SAMIR Medjekal

BENBELKHIR Fatma Zohra

Optimisation par planification expérimentale des paramètres de bioformulation des spores d’actinobactéries antagonistes et application dans le biocontrôle

Bensadek Zineb , Bensoucha Aya

Isolement, identification et applications des algues microscopiques

Djeraoui Ikram , Serrai Soumya

L’impact de l’alimentation sur le cancer: ente prévention et risque

Benbelkhir Fatma Zohra

Optimisation par planification expérimentale des paramètres de bioformulation des spores d’actinobactéries antagonistes et application dans le biocontrôle

SEDDIKI ISSAM , SLIMANI CHADA LOUBNA, MOHAMED SEGHIR ZEYNEB ; SLINI CHAIMA.

Activité antibactérienne de l'huile essentielle de clou de girofle sur la bactérie responsable des caries dentaires

MIMOUNE Khouloud , DILMI Houda Niamat ELLAH, MAHMOUDI Zeyneb

Évaluation de l’activité antimicrobienne de Salvadora persica et de Mentha Spicata contre un pathogène oral

Bakri aida , Dahdouh Nor el houda, Ben aicha hind Taous

Etude bibliographique de l’activité biologique (antibactérienne et antioxydante) de l’écorce de pin maritime

Dogha Nor , Mohamed chicouche serrine, Gherabi Ikram

Etude bibliographique sur l’antiobiorésistance et son impact environnemental

KROUMI Nour Elhouda , DOUCENE Mansora, BAGHDADI Widad, BELOUADAH Narimane

Évaluation de la qualité physicochimique et bactériologique de trois source d’eaux potable à Hammam Dalaa (M’Sila).

DAHMANI CHOAYB , MANSOURI CHAFEQ BARA, BERBACHE AHLEM, REZZIG AHLEM

Etude Ethnobotanique et inventaire des plantes médicinales utilisées pour les maladies bucco-dentairesdans la région de M’sila

KESSIS Aida , HADJI Laarem

Effet de l’utilisation des plantes aromatiques sur les propriétés physicochimiques, microbiologiques et sensorielles du fromage traditionnel Jben (Djben)

BOUGUERFA Wissam , DELHOUM Khawla

Évaluation de la qualité physicochimique et bactériologique de trois source d’eaux potable à BOUSAADA sud de M’sila

SOUICI Aicha , ARSLANE Douniya, FERHATI Zineb

Effet de l’utilisation de sirop de datte sur les qualités organoleptiques et sensorielles du Popcorn

CHERRID Saida , DAHMANI Nadjat

Les enzymes dans la technologie des détergents

Meftah saida , Mechegueg Khaoula

Les microalgueso traitement des eaux usées et applications

BEN SELHOUB ILHEM , SITOUF BOCHRA

ELABORATTON DE LAIT AROMATISE ABASE DE SIROP DE FIGUES SECHEES

AOUINA Meriem , BOUKHARI Siham

Transformation des produits alimentaires par les enzymes

MYAH Oumhani , TOUATI Fairouz

Etude phytochimique et biologique de l’espèce urtica

SALMI Radja , GHADBANE Asma

Etude phytochimique et biologique de l’espèce Ocimum basilicum dans la région de M’sila

ABDELLI Marwa , DENIDNI Zineb

Suivi des paramètres microbiologiques et physico -chimiques du jus d’orange « Ramy » au cours du stockage

LARBAOUI Fatima , MECHIKI Saliha

Étude de l'analyse fourragère et la production de gaz in vitro d'Artemisia herba alba dans la région de M'sila

ZIANI Djihad

ANALYSES FOURRAGERES DE Daucus sahariensis ET Artemesia herba alba DANS LA REGION DE M'SILA

Avian malaria is a serious disease affecting diverse bird species worldwide, caused by protozoan parasites of the genus Plasmodium and transmitted exclusively by infected mosquitoes. The parasite completes its life cycle in both the avian host and the mosquito vector, undergoing multiple developmental stages. Clinical signs range from mild to severe and may include lethargy, anemia, respiratory distress, altered feeding behavior, and reduced activity, with young or immunocompromised birds particularly vulnerable to mortality. Diagnosis relies on a combination of clinical observations and laboratory methods, including traditional blood smears and serology alongside molecular tools such as Polymerase Chain Reaction (PCR), Next-Generation Sequencing (NGS), metagenomics, and transcriptomics. Treatment options are limited, typically involving antimalarial drugs such as chloroquine phosphate, primaquine phosphate, mefloquine, sulfachloropyrazine, sulfaquinoxaline, Trimethoprim, and Pyrimethamine-sulfadoxine combination along with supportive care and environmental management. Control strategies target both vectors and hosts, including habitat modifcation, chemical application, chemo-sterilization, the use of endosymbionts like Wolbachia, housing management, drainage of water bodies, biosecurity measures, vaccination, and the rearing of genetically resistant avian breeds. Ongoing research into the ecology of avian malaria and its vectors is essential for developing effective prevention strategies and mitigating its impact on vulnerable bird populations. This review synthesizes current knowledge on the epidemiology, transmission dynamics, and ecological consequences of avian malaria, with the goal of informing conservation and management strategies.

Citation

Samir MEDJEKAL , , (2025-12-20), Avian malaria: an in-depth overview on its biology, epidemiology, pathogenesis, clinical features, economic impacts, diagnostic, treatment and control strategies, Journal of Parasitic Diseases, Vol:49, Issue:4, pages:1-40, Springer

Treatment for oral well-being conditions is costly and ordinarily not a portion of the inclusive well-being scope (UHC), and most low and middle-income nations are incapable of supplying administrations to anticipate and treat oral well-being conditions. Clove, the dried flowering bud of Syzygium aromaticum (L.) is widely used as a spice all over the world for its strong aromatic smell and Clove extracts. Our study aims to assess the impact of clove essential oil on the bacteria responsible for dental caries. The essential oil was extracted by hydro-distillation, and the bacteria were collected from a dentist in Bou-Saâda, then isolated and identified as Streptococcus mutans. The disk diffusion method is then used to assess antibacterial activity. Essential oil yield was 6.08%, antibacterial activity was determined on a Streptococcus mutans (Gram+) bacterial strain, inhibition diameters (inhibitionzone) ranged from 3 mm to 15 mm, minimum inhibitory concentration (MIC) for S.mutans was 0.19. From these results, we can conclude that Syzygium aromaticum clove essential oil exerts antibacterial power in vitro on the bacterial strain studied and may have a better in vivo effect on the incidence of reduced biofilm formation in dental caries. Key words: Syzygium aromaticum, essential oil, dental caries, antibacterial activity

Citation

Samir MEDJEKAL , ,(2025-04-15), Antimicrobial Activity of Syzygium aromaticum Essential Oil in Oral Health Treatment,Le 1er Séminaire national en Santé et Sécurité sanitaire des aliments M’sila, le 14 et 15 Avril 2025,Université Mohamed Boudiaf -M'sila

Description du sujet : Proteases represented 60–65% of the total industrial enzyme market, most of which are alkaline proteases. Most of these find applications in the food industry, in the meat tenderization process, peptide synthesis, for infant formula preparations, detergent formulations, baking and brewing. Objectifs : This study aim was alkaline protease characterization and production from local bacterial strain Halobacillus salinus DZ28. Méthode: In this subject, a new Algerian Gram-positive, rod-shaped, endospore-forming, salt-philic bacteria (DZ28 strain) that overproduce extracellular alkaline proteases have been isolated from salt lake deposits in Lake Oubeira, El Taref. Strain DZ28 was assigned as Halobacillus salinus DZ28 on the basis of phenotypic properties and 16S rDNA gene sequencing (ripotyping). Résultats et discussion : The maximum protease activity registered after 36 hours of incubation in optimized medium at 30° C was 19,000 U / ml in a shaking bottle culture at 160 rpm. The crude extract protease showed optimal activity at 60 ° C temperature and pH 12. It is actively inhibited by PMSF and DIFP, indicating that it belongs to the serine protease family. Interestingly, the crude extract protease was not only very stable to nonionic surfactants and oxidants, but also showed high stability and compatibility with some commercial detergents. It retaining more than 100% of its initial activity after pre-incubation for 1 h at 40°C with ISIS, followed by Pril (98%), Tide (95%) and Dixan (90%). Interestingly, the performance evaluation of the wash revealed that blood stains can be effectively eliminated at a temperature of 40°C for 1 hour with minimal supplementation (500 U/mL). Conclusion : This study represents the initial report of a protease derived from Halobacillus salinus, indicating its potential as a highly promising bioadditive for future applications in detergent formulations. Mots clés : Halobacillus salinus, Protease, detergent, Wash performance.

Citation

Samir MEDJEKAL , MOULOUD Ghadbane , Laid BENDERRADJI , ,(2025-04-15), Identification of a novel protease from Halobacillus salinus strain DZ28 isolated from salt lake sediments in Algeria and their use as detergent bioadditives,Le 1er Séminaire national en Santé et Sécurité sanitaire des aliments,Université Mohamed boudiaf-M'sila

Valorisation des souches d'actinobactéries natives pour le biocontrôle des pucerons noirsde fève.

Citation

Samir MEDJEKAL , ,(2024-10-16), Valorisation des souches d'actinobactéries natives pour le biocontrôle des pucerons noirsde fève,2ème Séminaire National sur L'Agropastoralisme,CRAPast (Djelfa), le 16 Octobre 2024.

This research highlights the efficiency of a bioinsecticide based on Streptomyces griseoflavus PAL114 in controlling black bean aphids and its effect on fava beans. Three actinobacterial strains were tested in vitro for their aphicidal activity. The PAL114 strain was then formulated in talc powder and tested again. Formulation processes were performed with four spore suspension densities (102, 10 4, 10 6 and 10 8 spore ml−1) at a rate of 25 ml per 100 g of talc powder. Furthermore, the in vivo effect of bioinsecticide on fava bean plants was studied in pot experiments using two application methods: spray and spray + soil amendment. The results showed that only the PAL114 strain had a highly significant effect on mortality (p = .001).

Citation

Samir MEDJEKAL , , (2024-07-22), Development of bioinsecticide based on Streptomyces griseoflavus PAL114 for control of black bean aphids Aphis fabae, Biocontrol Science and Technology, Vol:8, Issue:34, pages:736–753, Taylor and Francis

La fève Vicia faba occupe 44.3 % de la surface dédiée aux cultures des légumineuses en Algérie. Sa composition riche en protéines ainsi qu’aux capacités fixatrices d’azote sont à l’origine de leur importance économique, nutritionnelle et agricole. L’amélioration du rendement de cette culture peut être induite par l’utilisation des biofertilisants à base des microorganismes ayant un pouvoir de promotion de croissance tel que les actinobactéries. L’objectif de ce travail est d’étudier l’effet in vivo d’une formulation actinobactérienne sur la fève. La formulation est produite à partir de suspension sporale de Streptomyces sp inoculé dans la poudre du talc stérile. Cette formulation est ensuite appliquée aux plantules de fève d’une variété locale cultivées dans des pots pour étudier l’effet dans les conditions de serre. L’application est effectuée en deux modes de pulvérisation et de pulvérisation + amendement de sol avec un témoin négatif dont les plantules n’ont subi aucun traitement. Après 30 jours de culture, les résultats des deux traitements ont montré un effet positif et promotion de croissance par augmentation de taux de germination, de poids frais et sec et de longueur de plante et racine par rapport au témoin négatif. Nos résultats prouvent également l’efficacité de méthode d’application des bioformulations par pulvérisation et non seulement par amendement de sol. La présente recherche ouvre des perspectives d’essais en plein champ de fèves pour la valorisation des actinobactéries en termes de production des biofertilisants à moindre coût sans risques environnementaux. Mots clés : Fève, Actinobactéries, Bioformulation, Biofertilisant.

Citation

Samir MEDJEKAL , ,(2024-06-26), Etude de l’effet d’un biofertilisant formulé à base de spores d’actinobactérie sur la fève,1 st International Seminar of AgriFood and Industrial Biotectinology,KHEMIS MELIANA UNIVIERSITY ALGERIA

Chemical reagent effects on in vitro seed germination of Retama sphaerocarpa using various culture media unser salt and salt stress

Citation

Samir MEDJEKAL , ,(2024-05-07), Chemical reagent effects on in vitro seed germination of Retama sphaerocarpa using various culture media unser salt and salt stress,First Conference on Plant Biotechnology and Breeding,Ecole Nationale superieure de Biotechnologie de Constantine

Les maladies bucco-dentaires représentent le troisième fléau mondial après les maladies cardiovasculaires et le cancer par conséquent c'est l'une des maladies traitées par les pratiques populaires qui sont basées sur les plantes médicinales. Une série d'enquêtes ethnobotaniques a été réalisée à l’aide de fiches questionnaires dans la région de Sétif auprès des herboristes et des habitants. Ainsi, un total de 143 espèces, réparties dans 60 familles ont été recensées. En considérant les résultats obtenus, 86 espèces utilisées pour les maladies des gencives, 74 pour les douleurs dentaires, 35 pour l'halitose, 53 pour les aphtes ont été identifiés. Les plantes utilisées sont principalement préparées en décoction (80,4%). Syzygium aromaticum, Juglans regia et Salvadora persica sont les espèces les plus couramment prescrites par les herboristes locaux et les populations rurales.

Citation

Samir MEDJEKAL , ,(2024-05-06), Plantes utilisées pour les maladies bucco-dentaires dans la région de sétif: Aspects Ethnobotanique,Le 2 eme Colloque National de Chimie (CNC2@2024),Université Mohamed boudiaf -M'sila

The nutritive value of some Algerian perennial plants species were examined on the premise of their in vitro gas production, chemical composition and fermentation kinetics. The plant species were Aristida pungens, Artemesia herbaalba, Artemesia vulgarus, Atriplex halimus, Genista saharae, Lygeum spartum, Retama retam, Stipa tenacissima. L and oat hay as a standard. Importants variation have been registered (P <0.05) regarding all the chemical components of the perennial plants species. The crude protein (CP) content value ranged between 5.02 and 16.15 (% DM), the highest CP value was recorded for Atriplex halimus (A. halimus). Acid detergent fiber (ADF) and Neutral detergent fiber (NDF) were generally high in Stipa tenacissima and low in Atriplex halimus (P <0.05). The organic matter digestibility (OMD) and the total gas production vary from 31.74 to 59.1 % and 15.46 to 39.52 (ml.g-1 DM), respectively. In general, high values of Organic matter digestibility (OMD) and gas production were noted for A. halimus succeeded by Genista saharae (G. saharae). This necessitates prudent nutritional interventions such as supplementation with barley and wheat bran. Additionally, in order to improve fibrous feeds digestibility, some exogenous fibrolytic enzymes are of growing interest as additives to ruminant nutrition. A. halimus is a valuable plant that provides wildlife habitat and food for livestock. It is a very effective fodder element in mixed diets and as a supplement for livestock, mainly during the dry season in arid and semi-arid regions.

Citation

Samir MEDJEKAL , , (2023-08-10), CHEMICAL COMPOSITION AND IN VITRO RUMEN BIOGAS PRODUCTION OF SOME PERENNIAL PLANTS SPECIES, Journal of Animal and Plants Sciences, Vol:33, Issue:4, pages:998-1005, The Pakistan Agricultural Scientists Forum (PAS FORUM)

The main objective of the present study was to investigate a strategy to bioconverte spineless cactus Opuntia Ficus-Indica (O. ficus indica) Cladodes, Medicago sativa L. (M. sativa) and barley straw (H. vulgare) based on their chemical composition, in vitro digestibility and fermentation parameters. The CP ranged from 51.41 to 156.09 g/kg DM, which was especially high within M. sativa and low in H. vulgare. O. ficus indica had the highest values in free condensed tannins. The most digestible plant sample was that from M. sativa and O.ficus indica. The maximum in vitro gas production was recorded with M. sativa and H. vulgare. The same trend was observed with the total gas production (144 h). Based on the results, it can be concluded that O. ficus indica could replace common plant species, especially in the arid and semi-arid areas in which the livestock production section frequently suffers low efficiency and big losses.

Citation

Samir MEDJEKAL , , (2023-03-27), Potential of Opuntia Ficus-Indica Cladodes In M’sila (North ALGERIA) as feed for ruminants: chemical composition and in vitro assessment, Acta Agriculturae Scandinavica, Section A — Animal Science, Vol:70, Issue:4, pages:1-7, Taylor and Francis Online

The main objective of the present study was to evaluate the volatile fatty acids (VFAs) and methane (CH4) production of cactus Opuntia Ficus-Indica (O. ficus indica) Cladodes, Medicago sativa L. (M. sativa) and barley straw (H. vulgare) using chemical composition and in vitro gas production. There were significant (p<0.05) differences among studied samples in all measured nutrients except dry matter (DM) value. O. ficus indica showed particularly the highest Ash content (284.07 g/kg DM). The crude protein (CP) of the studied feedstuff ranged from 51.41 to 156.09 g/kg DM and it was especially high within M. sativa and low in H. vulgare. No significant difference was observed in pH values, total VFAs, propionate concentrations and CH4 production (ml/100 gas) among plants species studied. The lowest Acetate concentration was observed in H. vulgare (711.17 mmol/mol) and M. sativa (715.33 mmol/mol), respectively (p < 0.05). The maximum in vitro gas production was recorded with M. sativa and H. vulgare. Based on the results, it can be concluded that O. ficus indica could replace common plants species, especially in the arid and semi-arid areas in which livestock production frequently suffers from low efficiency and big losses. Furthermore, these plantations in agroforestry development could consolidate the protection of the environment against erosion, allowing the fixation of the soil and its protection against water erosion.

Citation

Samir MEDJEKAL , , (2023), ASSESSMENT OF VOLATILE FATTY ACIDS AND METHANE PRODUCTION IN VITRO OF OPUNTIA FICUS-INDICA CLADODES IN AN ALGERIAN ARID AREA, Journal of Applied Biological Sciences, Vol:17, Issue:1, pages:46-54, Anatolia Academy of Sciences

Fermented foods are among the primary source of human nutrition. In Algeria, traditional dairy products are the number one in the family economy. The Jben and Klila cheeses are two of the most popular varieties. The samples of traditional dairy products were collected from the rural area of the Djelfa. Twenty lactic acid bacteria strains were isolated and identified, all belonging to the genus Lactobacillus. Isolates were phenotypically characterized by their capability to ferment different carbohydrates. Among these isolates, four were identified as having a high antibacterial potential against Staphylococcus aureus ATCC 65 38. In this study we conclude that species of, Lactobacillus genus isolated from traditional dairy products has been shown to have an antagonistic activities to Staphylococcus aureus; this makes it of great importance in the food industry.

Citation

Samir MEDJEKAL , , (2023), Antimicrobial activity of Lactobacillus spp. against Staphylococcus aureus ATCC 65 38, Bulgarian Journal of Agricultural Science, Vol:29, Issue:1, pages:171-175, Agricultural Academy of Bulgaria

Centaurea parviflora (C. parviflora), belonging to the family Asteraceae, is an Algerian medicinal plant used in folk medicine to treat different diseases related to hyperglycemic and inflammatory disorders, as well as in food. The present study aimed to assess the total phenolic content, in vitro antioxidant and antimicrobial activity and phytochemical profile of the extracts of C. parviflora. The extraction of phenolic compounds from aerial parts was conducted using solvents of increasing polarity starting from methanol, resulting in crude extract (CE), to chloroform extract (CHE), ethyl acetate extract (EAE) and butanol extract (BUE). The total phenolic, flavonoid and flavonol contents of the extracts were determined using the Folin–Ciocalteu and AlCl3 methods, respectively. The antioxidant activity was measured with seven methods: 2,2- diphenyl-1-picrylhydrazyl (DPPH) assay, galvinoxyl free-radical-scavenging test, 2,20-Azino-Bis(3- Ethylbenzothiazoline-6-Sulfonic Acid) (ABTS) assay, cupric reducing antioxidant capacity (CUPRAC), reducing power, Fe+2-phenanthroline reduction assay and superoxide-scavenging test. The discdiffusion method aimed at testing the sensitivity of bacterial strains toward our extracts. A qualitative analysis with thin-layer chromatography of the methanolic extract was performed. Moreover, HPLC-DAD-MS was used to establish the phytochemical profile of the BUE. The BUE was found to contain high amounts of total phenolics (175.27 ± 2.79 µg GAE/mg E), flavonoids (59.89 ± 0.91 µg QE/mg E) and flavonols (47.30 ± 0.51 µg RE/mg E). Using TLC, different components such as flavonoids and polyphenols were noted. The highest radical-scavenging ability was recorded for the BUE against DPPH (IC50 = 59.38 ± 0.72 µg/mL), galvinoxyl (IC50 = 36.25 ± 0.42 µg/mL), ABTS (IC50 = 49.52 ± 1.54 µg/mL) and superoxide (IC50 = 13.61 ± 0.38 µg/mL). The BUE had the best reducing power according to the CUPRAC (A0.5 = 71.80 ± 1.22 µg/mL), phenanthroline test (A0.5 = 20.29 ± 1.16 µg/mL) and FRAP (A0.5 = 119.17 ± 0.29 µg/mL). The LC-MS analysis of BUE allowed us to identify eight compounds including six phenolic acids and two flavonoids: quinic acid, five chlorogenic acid derivatives, rutin and quercetin 3-O-glucoside. This preliminary investigation revealed that the extracts of C. parviflora have a good biopharmaceutical activity. The BUE possesses an interesting potential for pharmaceutical/nutraceutical applications.

Citation

Samir MEDJEKAL , , (2023), Phytochemicals, Antioxidant and Antimicrobial Potentials and LC-MS Analysis of Centaurea parviflora Desf. Extracts, molecules, Vol:28, Issue:2263, pages:1-22, MDPI

Centaurea parviflora (C. parviflora), belonging to the family Asteraceae, is an Algerian medicinal plant used in folk medicine to treat different diseases related to hyperglycemic and inflammatory disorders, as well as in food. The present study aimed to assess the total phenolic content, in vitro antioxidant and antimicrobial activity and phytochemical profile of the extracts of C. parviflora. The extraction of phenolic compounds from aerial parts was conducted using solvents of increasing polarity starting from methanol, resulting in crude extract (CE), to chloroform extract (CHE), ethyl acetate extract (EAE) and butanol extract (BUE). The total phenolic, flavonoid and flavonol contents of the extracts were determined using the Folin–Ciocalteu and AlCl3 methods, respectively. The antioxidant activity was measured with seven methods: 2,2- diphenyl-1-picrylhydrazyl (DPPH) assay, galvinoxyl free-radical-scavenging test, 2,20-Azino-Bis(3- Ethylbenzothiazoline-6-Sulfonic Acid) (ABTS) assay, cupric reducing antioxidant capacity (CUPRAC), reducing power, Fe+2-phenanthroline reduction assay and superoxide-scavenging test. The discdiffusion method aimed at testing the sensitivity of bacterial strains toward our extracts. A qualitative analysis with thin-layer chromatography of the methanolic extract was performed. Moreover, HPLC-DAD-MS was used to establish the phytochemical profile of the BUE. The BUE was found to contain high amounts of total phenolics (175.27 ± 2.79 µg GAE/mg E), flavonoids (59.89 ± 0.91 µg QE/mg E) and flavonols (47.30 ± 0.51 µg RE/mg E). Using TLC, different components such as flavonoids and polyphenols were noted. The highest radical-scavenging ability was recorded for the BUE against DPPH (IC50 = 59.38 ± 0.72 µg/mL), galvinoxyl (IC50 = 36.25 ± 0.42 µg/mL), ABTS (IC50 = 49.52 ± 1.54 µg/mL) and superoxide (IC50 = 13.61 ± 0.38 µg/mL). The BUE had the best reducing power according to the CUPRAC (A0.5 = 71.80 ± 1.22 µg/mL), phenanthroline test (A0.5 = 20.29 ± 1.16 µg/mL) and FRAP (A0.5 = 119.17 ± 0.29 µg/mL). The LC-MS analysis of BUE allowed us to identify eight compounds including six phenolic acids and two flavonoids: quinic acid, five chlorogenic acid derivatives, rutin and quercetin 3-O-glucoside. This preliminary investigation revealed that the extracts of C. parviflora have a good biopharmaceutical activity. The BUE possesses an interesting potential for pharmaceutical/nutraceutical applications. Keywords: antioxidant activity; antimicrobial; TLC; Centaurea parviflora; LC-MS; flavonoids; polyphenols

Citation

Samir MEDJEKAL , , (2023), Phytochemicals, Antioxidant and Antimicrobial Potentials and LC-MS Analysis of Centaurea parviflora Desf. Extracts, Molecules, Vol:28, Issue:2263, pages:1-22, MDPI

Natural dyes and pigments (vegetal, animal and microbial) are safer than synthetic dyes which have a polluting and harmful impact on the environment. Among natural microbial sources of pigments, microalgae are widely exploited for the production of phycobiliproteins, chlorophylls but especially carotenoids which have also health benefits. Production process of carotenoids from microalgae includes the steps of: biomass production and harvesting, extraction, saponification, separation and conservation. In this review the whole processes will be reviewed with special interest on different extraction steps and technics aiming to give a summarized overview of how carotenoids are produced from microalgae. Furthermore, improvements in cultivation and extraction systems, as well as carotenoid storage methods, are required for an economical, reproducible and ecofriendly large scale applications.

Citation

Fatma zohra BENBELKHIR , Samir MEDJEKAL , , (2022-08-23), Microalgal carotenoids: A promising alternative for synthetic dyes, Algal Reasearch, Vol:66, Issue:, pages:102823, Elsevier

Candidate genes expression for salinity tolerance was studied for both cationic transporters, namely: HKT1; 5 and HKT2; 1. The two genes were expressed in the root, and then, it showed that HKT1; 5 was better expressed in the root of HD cultivars. This suggests a more active function of HKT1; 5 genes in HD as a tolerant cultivar. Vacuolar antiporter Na+/H+, TNHX-1, expression was more elevated in roots, sheaths, and blades of HD than MD cultivar. Roots and sheaths of both two cultivars accumulate more transcripts of vacuolar TVP1 than the leaf blade. The two genes TNHX1 and TVP1 were expressed with high similarity in MD and HD cultivars, which suggesting equal efficiency storage in both genotypes. Na+/H+ antiporter localized in the plasma membrane (TaSOS1) was more accumulated in roots and sheaths of MD comparative to HD cultivar; suggesting that in addition to higher retention of Na+ in sheaths, HD prevents the accumulation of Na+ in the blade by activating its efflux via a high expression of the gene SOS1. Results showed that salinity tolerance in wheat (Triticum aestivum L.) is concordant to the ability to prevent Na+ accumulation toxic levels, linked to a high osmoregulation capacity coupled with an acceptable K+ level in the blade

Citation

Samir MEDJEKAL , , (2022-04-06), Multiple Genes (SOS, HKT, TVP) Expression in Two Contrasting Bread Wheat (Triticum aestivum L.), Cultivars on In Vitro Saline Stress Conditions, Sustainable Energy-Water-Environment Nexus in Deserts, Advances in Science, Technology & Innovation,, Vol:1, Issue:1, pages:635-642, Springer

A total of 33 lactic acid bacteria (LAB) were isolated from 5 samples of traditional dairy product (Jben) collected from various livestock farms in Oued El Malha, Djelfa, the Ouled Naïl Range of north-central Algeria. The taxonomic study of the strain B04 using a multiphase approach based on morphology, physiology, molecular (16S rRNA) and phylogenetic analyses allowed correlating this strain to Enterococcaceae. The difference of the 16S rRNA gene sequence of the isolate toward the most closely related genus Enterococcus was more than 6 % suggesting that the strain B04 represents a new genus. The results of the evaluation of some physiological tests indicated that B04 exhibited good biological activities including acidifying, proteolytic and bacterial inhibition. The strain B04 was antagonistic toward Staphylococcus aureus ATCC 6538, Escherichia coli ATCC 25922, and Bacillus cereus ATCC 10876.

Citation

Samir MEDJEKAL , , (2022), Phenotypic, genotypic, and technological characterization of new lactic acid bacterium isolated from traditional dairy product in Djelfa, Algeria, Nova Biotechnologica et Chimica, Vol:21, Issue:2, pages:e904, Nova Biotechnologica et Chimica

Date palm (Phoenix dactylifera L.) of Boussaâda has varietal diversity and a very important nutritional value in Algeria. Nevertheless, today the palm groves are threatened, not only climatically but also in terms of varietal diversity such as disappearance of varieties, the low production and even discharges serving mainly to vegetative propagation which can be used as a source of explants on in vitro somatic embryogenesis technique. The aim of this study is to use in vitro culture techniques to regenerate the phoenicicultural orchards at Boussaâda oasis. Two types of experimental protocol are used; firstly, to make an inventory in field in order to contain palm groves and then date palms existing; and the secondly is to applicant the somatic embryogenesis technique in the laboratory and then regenerate the good cultivar. Results indicate that plant growing is an important axis that needs to be developed in the oasis by introducing varieties to select the most suitable and profitable for a good diversification of cultivars and consequently the improvement of production.

Citation

Samir MEDJEKAL , , (2022), In vitro effects of culture media on potential regeneration of date palm (Phoenix dactylifera L.) in Boussaâda oasis, Algeria, Journal of Oasis Agriculture and Sustainable Development, Vol:1, Issue:2, pages:87-92, Institut des zones arides

The objective of the study was to evaluate the nutritional value of some native plants, collected from Algerian arid zones by in vitro gas production method. The volatile fatty acids (VFA) of samples were also determined in the culture medium. This work was carried out in 2011 and was conducted in comparison to a control substrate (oat vetch) considered as a reference plant in literature. The selected plants were collected in the arid areas of the Algerian desert. Nine forages including six dicotyledon plants (Atriplex halimus L., Artemisia campestris L., Artemisia herba-alba subsp. valentina, Astragalus gombiformis Pomel, Spartidium saharae (Coss. & Dur.) and Retama raetam Forssk., and three monocotyledon plants (Stipagrostis pungens (Desf.), Lygeum spartum L.and Stipa tenacissima L.) were selected. A. campestris, A. gombiformis and A. herba-alba recorded the highest values of gas production. The total VFA production of the different substrates is significantly different between them (p<0.0001). A. gombiformis had the highest total VFA (34.7 mmol/L) followed by A. campestris (32.8 mmol/L), while the lowest total production of VFA was observed in S. tenacissima (17.3 mmol/L). Generally, the plant studied can be classified in two groups, one group with poor-quality grasses (L. spartum. and S. tenacissima) and other with higher digestibility (A. gombiformis and Artemisia spp.). In conclusion, dicot species are therefore recommended for feeding ruminants.

Citation

Samir MEDJEKAL , , (2021-05-16), In vitro Gas Production and Fermentation Parameters of Some Plants Species Collected from Algerian Arid Rangelands, Journal of Rangeland Science, Vol:12, Issue:1, pages:77-86, Islamic Azad University

Rhizobia andmycorrhizalfungi promote non-Legumes growth.This study investigated the ability of Rhizobium leguminosarum GM01 and Glomus spp. A01 isolates on the growth and uptake of lead (Pb) by date palm (Phoenix dactylifera L.) grown in heavy metal-polluted soils. The combination of A01 with GM01 increases the mycorrhizal colonization of date palm by arbuscular mycorrhizal fungi (AMF) with frequency (F%) of 86.67%. The selected isolates GM01 and A01 increased all plant growth parameters of date palm. The initial results indicate that the AMF and Rhizobium as a promising agent for promoting growth of plants. The metal tolerance trait exhibited by A01 and GM01 strains indicates their potentials as effective agents for phytoremediation of heavy metals in polluted environments. This ability may be of particular importance during restoration practices into habitats with a history of heavy metal pollution.

Citation

Samir MEDJEKAL , , (2021-04-10), Assessment of Arbuscular Mycorrhizal Fungi Status and Rhizobium on Date Palm (Phoenix dactylifera L.) Cultivated in a Pb Contaminated Soil, Recent Advances in Environmental Science from the Euro-Mediterranean and Surrounding Regions (2nd Edition), Environmental Science and Engineering,, Vol:2, Issue:1, pages:703-707, Springer

Heavy metal pollution of the soil is a relevant environmental problem. Plant growth promoting and tolerance heavy metal bacteria are a promising technique for phytoremediation. The aim of this study was to isolate heavy metaltolerant rhizobia from Calobota saharae. Tolerance to a range of heavy metal ions was determined by minimal inhibitory concentration (MIC) for Rhizobia which was isolated from Calobota saharae. The Rhizobium leguminosarum GM01 strain exhibited strong tolerance to a range of heavy metals including lead (Pb), Cobalt (Co), and zinc (Zn). R. leguminosarum GM01 have great potentials for plant growth promotion and phytoremediation of contaminated soils

Citation

Samir MEDJEKAL , , (2021-04-10), Plant Growth Promoting and Heavy Metal-Tolerant Rhizobia from Algeria, Recent Advances in Environmental Science from the Euro-Mediterranean and Surrounding Regions (2nd Edition), Environmental Science and Engineering,, Vol:2, Issue:1, pages:697-701, Springer

The chemical composition and phenolic compounds of eight herbals (Alpinia officinarum, Artemisia absinthium, Cuminumcyminum, Dittrichia viscosa, Mentha rotundifolia L., Nigella sativa, Rosmarinus officinalis L., and Zingiber officinale) were evaluated. Feed components were determined by proximate analysis, whereas phenolic and tannin compounds were analyzed by colorimetric procedures. The crude protein content of the herbal samples varied widely, being particularly high for Nigella sativa and low for Alpinia officinarum and Rosmarinus officinalis. The highest contents of total extractable phenols (TEP) and total extractable tannins(TET) were observed in the Cuminumcyminum and Dittrichiaviscose whereas herbals, Nigella sativa and Zingiber officinale showed lower concentrations. The tannin concentration varied considerably between species, but in general, the plants investigated in this study had low tannin contents (except for Alpinia officinarum). Based on the results above, it could be concluded that a large reserve of herbal species in the local flora is available that could be potentially used as additives for livestock feeding. These herbs appear to be promising alternatives to antibiotics in altering rumen fermentation and reducing methane production in ruminants.

Citation

Samir MEDJEKAL , ,(2021), Comparing Chemical Composition and Phenolic Compounds of Some Herbals as Potential Feed Additives in Ruminant Nutrition,Euro-Medeterranean conference for environmental integration,TUNISIA

Ocimum basilicum est une plante médicinale appartenant à la famille des Lamiaceae, elle est aromatique et donc riche en huiles essentielles (HEs). Notre travaille nous a permis de mettre en évidence le rendement des HEs ainsi que les tests phytochimiques et une étude des activités biologiques des HEs de quelque travaux précédentes. Le rendement d’extraction des huiles essentielles est 0.96%. Les tests phytochimiques ont mis en évidence la présence des polyphénols, flavonoïdes, alcaloïdes, tèrpenoïdes, tanins, ainsi que les coumarines et l’absence des anthocyanes et des saponines. L’activité antioxydante a été évaluée par la méthode de réduction de radical DPPH. Les résultats obtenus par les chercheurs ont montré que l’huile essentielle peut agir en tant que piégeurs de radicaux. L'activité antimicrobienne de l'huile essentielle des feuilles de la plante qui appliquée par les chercheurs contre certaines souches de bactéries et de champignons. Les résultats révèlent que les huiles essentielles possèdent un pouvoir antimicrobien sur les bactéries à Gram + plus que sur les bactéries à

Citation

Samir MEDJEKAL , ,(2021), Etude phytochimique et biologique de l’espèce Ocimum basilicum dans la région de M’sila,International Seminar on Biodiversity, Valorisation and Conservation of Urban and Forest Ecosystems: (In support of sustainable development),Université Mohamed Boudiaf M'sila

Urtica dioica est une plante herbacée, appartenant à la famille des Urticacées. Elle est utilisée dans différents domaines depuis la préhistoire. Le présent travail a comme but l’étude phytochimique de cette plante et également des extraits de la partie racinaire et de la partie aérienne. Les résultats des tests phytochimiques ont révélés la richesse d’extrait de la partie aérienne en composés phénoliques (flavonoïdes, polyphénols, tanins, anthraquinones et anthocyanes) et aussi en stérols et triterpènes. Cependant une présence des flavonoïdes, alcaloïdes, anthocyanes et triterpènes en faible quantité est marqué pour l’extrait de la partie racinaire. On note l’absence totale des coumarines, des saponosides et des quinones dans les deux extraits. Concernant les études réalisées sur les activités biologiques, elles ont montrées186 que cette plante est dotée des effets biologiques y compris d’activité antibactérienne contre quelques bactéries Gram positif et Gram négatif avec des zones d’inhibition allant jusqu’à 27 mm chez l’espèce Klebsiella pneumoniae, une activité antifongique contre certaines espèces fongiques ; avec une inhibition de 73% de croissance chez Alternaria solani, ainsi qu’une activité antioxydante hautement significative. L’ensemble de ces résultats suggèrent que cette plante peut être utilisé dans plusieurs domaines et plus particulièrement thérapeutiques et nutritionnel.

Citation

Samir MEDJEKAL , ,(2021), Etude phytochimique et biologique de l’espèce Urtica dioica L.,International Seminar on Biodiversity, Valorisation and Conservation of Urban and Forest Ecosystems: (In support of sustainable development),Université Mohamed Boudiaf M'sila

The objective was to evaluate levels of phenolics and tannins antinutritive factors of various Algerian shrubs and browse species (Arthrocnemum macrostachyum, Atriplex canescens, Artemesia herbaalba, Astragalus gombo, Calobota saharae Ceratonia siliqua (Pods), Gleditschia triacanthos (Pods), Hedysarum coronarium, Medicago sativa, Ononis natrix L, Hordeum vulgare (Straw) and Stipa tenacissima L.) grown in arid and semi-arid areas. Phenolic compounds were extracted following the procedures described by Makkar (2003) and determined using the Folin-Ciocalteau reagent and tannic acid as standard.The Total extractable phenols (TEP) content varied widely from 3.02 g.kg-1 DM in S. tenacissima to 85.30 g.kg-1 DM in G. triacanthos, whereas the content of Total extractable tannins (TET) ranged from 12.80 g.kg-1 DM in C. Saharae to 69.92 g.kg-1 DM in A. macrostachyum. The Free condensed tannins FCT varied widely from 4.6 g.kg-1 DM in A. herba-alba to 525.0 g.kg-1 DM in C. siliqua pods. Total condensed tannins TCT varied widely among species, being highest in C. siliqua and lowest in H. vulgare. The analysis of specific tannins gives an indication of the presence of some anti-nutritive factors in browse. Except for some few species (C. siliqua pods, G. triacanthos pods and H.coronarium, the plants material investigated in this study had low tannin contents, particularly in M.sativa, A. macrostachyum and c. saharae which would be of little significance in their effects on digestion of nutrients by ruminants. Low tannin contents may be beneficial to ruminants due their effect in reducing rumen degradation of forage proteins, which can be digested post-ruminally. However, high tannin contents in nutritionally important forage trees, shrubs, legumes, cereals and grains often limits their utilization as feeds tuffs.

Citation

Samir MEDJEKAL , , (2020-01-01), Total phenolic and tannins contents of some Algerian shrubs and browse species, Revue des Régions Arides. 46 (1): 79-81, Vol:46, Issue:1, pages:79-81, Revue des régions arides

This study investigated the ability of Streptomyces spp. and Glomus spp. isolates to control the fusarium wilt pathogen of date palm (Phoenix dactylifera L.), Fusarium oxysporum f.sp. albedinis, as well as the effect of these isolates on plant growth in the presence and absence of the pathogen. The genus Glomus is the most abundant fungi in rhizosphere of date palm in Biskra from Algeria. Streptomyces spp. BI21 showed the largest zone of inhibition against F. oxysporum f.sp. albedinis (35 ± 3 mm). In the absence or presence of the pathogen, the Streptomyces spp. BI21 and Glomus spp. A01 isolates increased all plant growth parameters of date palm. The initial results indicate the arbuscular mycorrhizal fungi and Streptomyces as a promising biocontrol agent for promoting growth of plants and also controlling palm date Fusarium wilt disease.

Citation

Samir MEDJEKAL , , (2020-01-01), Impact of Streptomyces spp. and Glomus spp. on growth of date palm (Phoenix dactylifera L.) and suppression of fusarium wilt. Revue des Régions Arides., Revue des Régions Arides, Vol:46, Issue:1, pages:735-747, Revue des régions arides

Messaâd forest is the richest and most diverse flora. Ethnobotanical surveys carried out among different categories of inhabitants bordering the study area have enabled us to identify 81 medicinal species belonging to 42 botanical families. The survey analysis shows that Asteraceae family is the highest dominant with 13.5% followed by the Lamiaceae family with 12.34%. These two families are the most abundant in the study area. Preparation methods of the most plants used by the inhabitants are the decoction with 38% then the infusion with 34%. The parts of the plants most used in traditional medicine are the leaves with 32%. Surveys have also shown that women have more knowledge of traditional medicine than men.

Citation

Samir MEDJEKAL , , (2020-01-01), Forêt de Djebel Messaâd dans la région de Boussaâda (Sud-Algérien) : Inventaire et utilisation thérapeutique de quelques plantes médicinales. Revue des Régions Arides., Revue des Régions Arides, Vol:46, Issue:1, pages:83-89, Revue des régions arides

The chemical composition and digestibility of twelve plant samples (Arthrocnemum macrostachyum, Atriplex canescens, Artemesia herba-alba, Astragalus gombo, Calobota saharae Ceratonia siliqua, Gleditsia triacanthos, Hedysarum coronarium, Medicago sativa, Ononis natrix L, Hordeum vulgare and Stipa tenacissima L.) grown in arid and semi-arid areas of Algeria were evaluated (in 2010). Feed components were determined by proximate analysis whereas phenolic and tannin compounds were analyzed by colorimetric procedures. Digestibility was assessed by conventional gravimetric in vitro and in situ methods. In general, crude protein content in dicotyledon (dicots) species was always greater than that in monocotyledon (monocots) grass showing higher Neutral and Acid Detergent Fiber (NDF and ADF) and lower lignin contents than dicots. The tannin concentration varied considerably between species, but in general, the plants investigated in this study had low tannin contents (except for Ceratonia siliqua, Gleditsia triacanthos and Hedysarum coronarium). Monocots showed lower in vitro and in situ, fermentation rate and cumulative gas production than dicots species. This study indicated that a large reserve of plant species in the local flora is available that could be potentially used for livestock feeding. These feeds, if fully exploited, could assist in increasing the level of production and productivity of the livestock resources in the region.

Citation

Samir MEDJEKAL , , (2020), Chemical Composition, In Situ Degradation and Fermentation Kinetics of Some Browse Plant Species Collected from Algerian Arid and Semi-Arid Areas, Journal of Rangeland Science, Vol:10, Issue:2, pages:188-204, IA University, Borujerd Branch

Following the trends in human health care towards herbal medicinal products and plant derived dietary supplements also in Veterinary medicine and livestock produc-tion an increasing use of herbs, essential oils and plant extracts can be observed. Herbs offer a new perspective in the strategy to achieve lower antibiotic use on farm, both to contrast antibiotic resistance and to reduce veterinary bills. As there is little information regarding the nutritive value of locally available herbs so the study was conducted to compare chemical composition and phenolic compounds of the different species of herbs as potential feed additives in ruminats animals. Eights herbals were used in this study: Alpinia officinarum (A. officinarum), Arte-misia absinthium (A. absinthium), Cuminum cyminum (C. cyminum), Dittrichia visco-sa (D. viscosa), Mentha rotundifolia L. (M. rotundifolia L.), Nigella sativa (N. sati-va), Rosmarinus Officinalis L. (R. Officinalis L.), Zingiber Officinale (Z. Officinale). Feed samples were analysed for Dry matter (DM) and following the method of AOAC (2000). Nitrogen was determined using the micro-Kjeldahl method (AOAC 2000). Crude Protein (CP) was calculated as N x 6.25. The Neutral Detergent Fiber (NDF), Acid Detergent Fiber (ADF) and Acid Detergent Lignin (ADL) were analyzed according to Van Soest et al. (1991) using the ANKOM Fiber Analyzer (ANKOM Technology, Fairport, NY). Based on the results above, it could be concluded that a large reserve of herbal species in the local flora is available that could be potentially used for livestock feeding. These herbs appear to be promising alternatives to antibiotics in altering rumen fermentation and reducing methane production in ruminants.

Citation

Samir MEDJEKAL , ,(2019), Comparing chemical composition and phenolic compounds of some herbals as potential feed additives in ruminant Nutrition,Euro-Mediterranean Conference for Environmental Integraion,Tunisia

Abstract The arid zones of North Africa are characterized by the dominance of date palm trees (Phoenix dactilyfera L.), which the vegetation represents more than 10 million date palm trees in Algeria. The yearly maintenance of date palm trees let considerable quantities of green leaves, roughly 20 kg per tree. This date palm by-product is traditionally used as complementary feeding source for livestock by oasian people. Then, the main objective of this study is assessing the nutritive value of agricultural by-products dry palm leave, Aristida pungens (local name: Drinn) in comparison to barley straw by chemical analysis, rumen fermentation characteristics and gas production technique in vitro. A quantitative analysis of gases produced from dry palm leaves was compared to that of Drinn and barley straw which are common feeds in the semi-arid and arid regions of Algeria. The results obtained show that the activity of goats’ rumen microflora is very important on the studied substrate of the arid regions, which indicates very significant digestibility coefficient. This situation is certainly due to the high content of barley straw of total soluble sugars and thus more easily fermentable. For dry palm leaves, the value of in vitro digestibility is 49.8 %. It is close to that of Drinn, probably owing to the fact that these substrates present almost the same level of lignin and of cellular wall contents. These results suggest a high potential of integrating dry palm leaves in ruminants’ feed in these areas leading to overcoming the problems of maintaining feed supply. Key words: In vitro fermentation, Dry palm leaves, Nutritive value, Rumen microflora

Citation

Samir MEDJEKAL , ,(2019), Nutritive Value Assessment of Phoenix Dactilyfera L. Leaves by Rumen Fermentation In Vitro,The international seminar of processing technologies of agricultural products in the Saharan regions,Douz - Tunisia

Evaluation de la valeur nutritionnelle des palmes sèches d’une région aride de l’Algérie par la technique de production de gaz in vitro Les palmes sèches sont produites annuellement en quantité appréciable et sont occasionnellement introduites dans l’alimentation du bétail des régions arides, sans pour autant que l’on connaisse leur valeur alimentaire. Dans cette étude, nous avons tenté de contribuer à caractériser l’apport réel de ce substrat à l’alimentation du bétail des régions arides. Dans ce cadre, nous avons utilisé la technique de production de gaz in vitro de MENKE , modifiée par LY et PEDRAZA qui ont permis à la méthode de base de refléter fidèlement l’intensité de l’activité microbienne en déterminant spécifiquement les apports spécifiques des différentes fractions pariétales, fraction soluble et fraction insoluble, au pool gazeux final. L’analyse quantitative de la production des gaz fermentaires à partir des palmes sèches est comparable à celle du Drinn mais elle reste toujours inférieure, comparativement à la paille d’orge. Cette situation est certainement dû à la teneur plus élevée de la paille d’orge en sucres totaux solubles et donc plus aisément fermentescibles. Alors que les teneurs plus importantes en ADF et NDF, en général complexés en composés ligno-cellulosiques, des palmes sèches et du Drinn constituent un facteur limitant majeur de leur fermentation. Il est maintenant nécessaire de compléter les lacunes des rations alimentaires par l’utilisation de sous produits de l’agronomie saharienne tels les palmes sèches et la paille d’orge ainsi que le Drinn. Leur valeur alimentaire est prouvée et ils peuvent contribuer à la satisfaction des besoins alimentaires des animaux, par leur potentiel de production d’AGV. Mots clés: microflore ruminale, production de gaz in vitro , Drinn

Citation

Samir MEDJEKAL , ,(2019), Université Mohamed boudiaf-M'sila,1er Séminaire National de l’Apport des Biotechnologies pour la Protection de l’Environnement ,15-16 décembre 2019,Université Mohamed boudiaf-M'sila

Etude de l’analyse fourragère et de production de gaz in vitro d’Artemisia herba alba dans la région de M’sila Ce travail avait pour objectif principal l’étude de valeur nutritive de la plante fourragère (Artemisia herba alba) destiné à l'alimentation des bétails dans la région de Msila et la paille d'orge comme substrat standard à travers plusieurs aspects: La caractérisation chimique et phytochimique de ces plantes et l’étude de l'activité fermentaire in vitro de la microflore ruminale des ovins par la mesure de la production de gaz. En premier lieu, l’estimation de la valeur nutritive de substrats retenus porte sur la détermination de leurs composition chimique (matière sèche, matière organique, matière minérale, matières azotée totale, fibres, composés secondaires). La deuxième partie est consacrée à l’étude de l’évaluation biologique de leur fermentation in vitro par le microbiote ruminal d’ovin selon la technique de production de gaz in vitro. L’analyse chimique révèle que le substrat est caractérisé par un teneur intermédiaire de MS (40%), teneur élevée en MO (91.17%) et une teneur faible en MM (8.83%), une faible teneur en constituants pariétaux (NDF et ADF) aussi est caractérisé par sa richesse en matières azotées (13.51%). Par contre, elles contiennent une très faible quantité en composés phénoliques. (TPT:25,14g/kg; TC:22.5g/kg). Les résultats de la fermentation in vitro par le microbiote ruminal des ovins révèlent que la production de gaz totale, engendrée par la dégradation anaérobie de ces substrats, montre que la plante testé (A. herba alba) est dégradée à un niveau élevé par apport à notre substrat de référence la paille d'orge. Le profil fermentaire de dégradation des substrats in vitro s’oriente vers une production accrue en dioxyde de carbone (CO2). Mots clés: A.herba alba, analyse chimique, microbiote ruminale, fermentation.

Citation

Samir MEDJEKAL , ,(2019), Université Mohamed boudiaf-M'sila,1er Séminaire National de l’Apport des Biotechnologies pour la Protection de l’Environnement ,15-16 décembre 2019,Université Mohamed boudiaf-M'sila

The chemical composition and digestibility of twelve plant samples (Arthrocnemum macrostachyum, Atriplex canescens, Artemesia herba-alba, Astragalus gombo, Calobota saharae Ceratonia siliqua, Gleditsia triacanthos, Hedysarum coronarium, Medicago sativa, Ononis natrix L, Hordeum vulgare and Stipa tenacissima L.) grown in arid and semi-arid areas of Algeria were evaluated (in 2010). Feed components were determined by proximate analysis whereas phenolic and tannin compounds were analyzed by colorimetric procedures. Digestibility was assessed by conventional gravimetric in vitro and in situ methods. In general, crude protein content in dicotyledon (dicots) species was always greater than that in monocotyledon (monocots) grass showing higher Neutral and Acid Detergent Fiber (NDF and ADF) and lower lignin contents than dicots. The tannin concentration varied considerably between species, but in general, the plants investigated in this study had low tannin contents (except for Ceratonia siliqua, Gleditsia triacanthos and Hedysarum coronarium). Monocots showed lower in vitro and in situ, fermentation rate and cumulative gas production than dicots species. This study indicated that a large reserve of plant species in the local flora is available that could be potentially used for livestock feeding. These feeds, if fully exploited, could assist in increasing the level of production and productivity of the livestock resources in the region.

Citation

Samir MEDJEKAL , , (2019), Chemical Composition, In Situ Degradation, And Fermentation Kinetics Of Some Browse Plant Species Collected From Algerian Arid And Semi-Arid Areas, Journal of rangeland science, Vol:10, Issue:2, pages:1-10, IA University, Borujerd Branch

The aim of this study was to determine the chemical composition and in vitro digestibility, and to estimate the in vitro fermentation parameters of palm leaves and pedicels from Ghars palm variety. A rumen in situ technique was also used to examine In vitro Digestible Dry Matter (IDDM), In vitro Digestible Crude Protein (IDCP), and In vitro Digestible Neutral Fiber (IDNF), and rate and extent of gas production. Vetch-oat hay was taken as a reference feed material. The samples were collected in Tolga district (southeast Algeria). TheCrude Protein (CP) content of the plant species was low for pedicels and palm leaves (33 and 60 g kg−1 DM, respectively). The highest content of total extractable phenols, tannins and condensed tannins was observed in palm leaves whereas pedicels showed lower concentrations. In vitro digestibility and in situ DM disappearance were slightly different for the examined forages. Analogue trends were observed for the in vitro fermentation kinetics estimated from the gas production curves. Pedicels showed the highest DM effective degradability (ED; assuming a passage rate of 0.03 h-1) whereas palm leaves seemed to be a poorly degradable material with an ED coefficient of 0.39 and 0.14 g g -1DM, respectively. Despite the moderate CP and high fiber content along with in vitro digestibility and in situ DM disappearance found in pedicels, in comparison with vetch oat hay degradation, it indicated that this plant could have a greater nutritional value. Dry matter disappearance after 144 h of incubation was negatively correlated with phenolic compounds and total extractable tannins, suggesting that the in vitro techniques can be appropriate for detecting the presence of anti-nutritional substances in shrubs. Key Words: Chemical composition, In vitro digestibility, In situ technique, Tannins, Palm date

Citation

Samir MEDJEKAL , , (2019), Comparing Chemical Composition and Digestibility of Pedicels and Palm Leaves as a Source for Livestock Feeding by in vitro and in situ Techniques, Journal of rangeland science, Vol:9, Issue:4, pages:378-391, IA University, Borujerd Branch, IRAN

Les palmes sèches sont produites annuellement en quantité appréciable et sont occasionnellement introduites dans l’alimentation du bétail des régions arides, sans pour autant que l’on connaisse leur valeur alimentaire. Dans cette étude, nous avons tenté de contribuer { caractériser l’apport réel de ce substrat { l’alimentation du bétail des régions arides. Dans ce cadre, nous avons utilisé la technique de production de gaz in vitro de MENKE , modifiée par LY et PEDRAZA qui ont permis { la méthode de base de refléter fidèlement l’intensité de l’activité microbienne en déterminant spécifiquement les apports spécifiques des différentes fractions pariétales, fraction soluble et fraction insoluble, au pool gazeux final. L’analyse quantitative de la production des gaz fermentaires à partir des palmes sèches est comparable à celle du Drinn mais elle reste toujours inférieure, comparativement { la paille d’orge. Cette situation est certainement dû { la teneur plus élevée de la paille d’orge en sucres totaux solubles et donc plus aisément fermentescibles. Alors que les teneurs plus importantes en ADF et NDF, en général complexés en composés ligno-cellulosiques, des palmes sèches et du Drinn constituent un facteur limitant majeur de leur fermentation. Il est maintenant nécessaire de compléter les lacunes des rations alimentaires par l’utilisation de sous produits de l’agronomie saharienne tels les palmes sèches et la paille d’orge ainsi que le Drinn. Leur valeur alimentaire est prouvée et ils peuvent contribuer à la satisfaction des besoins alimentaires des animaux, par leur potentiel de production d’AGV.

Citation

Samir MEDJEKAL , ,(2019), Evaluation de la valeur nutritionnelle des palmes sèches d’une régions aride de l’Algérie par la technique de la production de gaz in vitro,1er Séminaire National de l’Apport des Biotechnologies sur la Protection de l’Environnement Université Mohamed Boudiaf-M’sila,Université Mohamed Boudiaf M'sila

Ce travail avait pour objectif principal l’étude de valeur nutritive de la plante fourragère (Artemisia herba alba) destiné à l'alimentation des bétails dans la région de Msila et la paille d'orge comme substrat standard à travers plusieurs aspects: La caractérisation chimique et phytochimique de ces plantes et l’étude de l'activité fermentaire in vitro de la microflore ruminale des ovins par la mesure de la production de gaz. En premier lieu, l’estimation de la valeur nutritive de substrats retenus porte sur la détermination de leurs composition chimique (matière sèche, matière organique, matière minérale, matières azotée totale, fibres, composés secondaires). La deuxième partie est consacrée { l’étude de l’évaluation biologique de leur fermentation in vitro par le microbiote ruminal d’ovin selon la technique de production de gaz in vitro. L’analyse chimique révèle que le substrat est caractérisé par un teneur intermédiaire de MS (40%), teneur élevée en MO (91.17%) et une teneur faible en MM (8.83%), une faible teneur en constituants pariétaux (NDF et ADF) aussi est caractérisé par sa richesse en matières azotées (13.51%). Par contre, elles contiennent une très faible quantité en composés phénoliques. (TPT:25,14g/kg; TC:22.5g/kg). Les résultats de la fermentation in vitro par le microbiote ruminal des ovins révèlent que la production de gaz totale, engendrée par la dégradation anaérobie de ces substrats, montre que la plante testé (A. herba alba) est dégradée à un niveau élevé par apport à notre substrat de référence la paille d'orge. Le profil fermentaire de dégradation des substrats in vitro s’oriente vers une production accrue en dioxyde de carbone (CO2).

Citation

Samir MEDJEKAL , ,(2019), Etude de l’analyse fourragère et de la production de gaz in vitro d’Artemisia herba alba dans la région de M’sila,1er Séminaire National de l’Apport des Biotechnologies sur la Protection de l’Environnement Université Mohamed Boudiaf-M’sila,Université Mohamed Boudiaf M'sila

The arid zones of North Africa are characterized by the dominance of date palm trees (Phoenix dactilyfera L.), which the vegetation represents more than 10 million date palm trees in Algeria. The yearly maintenance of date palm trees let considerable quantities of green leaves, roughly 20 kg per tree. This date palm by-product is traditionally used as complementary feeding source for livestock by oasian people. Then, the main objective of this study is assessing the nutritive value of agricultural by-products dry palm leave, Aristidapungens (local name: Drinn) in comparison to barley straw by chemical analysis, rumen fermentation characteristics and gas production technique in vitro. A quantitative analysis of gases produced from dry palm leaves was compared to that of Drinn and barley straw which are common feeds in the semi-arid and arid regions of Algeria. The results obtained show that the activity of goats‟ rumen microflora is very important on the studied substrate of the arid regions, which indicates very significant digestibility coefficient. This situation is certainly due to the high content of barley straw of total soluble sugars and thus more easily fermentable. For dry palm leaves, the value of in vitro digestibility is 49.8 %. It is close to that of Drinn, probably owing to the fact that these substrates present almost the same level of lignin and of cellular wall contents. These results suggest a high potential of integrating dry palm leaves in ruminants‟ feed in these areas leading to overcoming the problems of maintaining feed supply.

Citation

Samir MEDJEKAL , ,(2019), NUTRITIVE VALUE ASSESSMENT OF PHOENIX DACTILYFERA L.LEAVES BY RUMEN FERMENTATION IN VITRO,The 1st international seminar of processing technologies of agricultural products in the Saharan regions TAGS_2019,Tunisia

he objective of the study was to determine the in vitro rumen fermentation end-products of 10 browse species. Serum bottles containing 500 mg of substrate, 10 ml of sheep rumen fluid and 40 ml of buffered medium were incubated for 24 h. After incubation, pH, methane and volatile fatty acid (VFA) productions were recorded. There were differences among feedstuffs (p < .05) in pH and VFA production. Astragalus gombo resulted in the highest and Stipa tenacissima in the lowest VFA production. Gas production was highest for Medicago sativa and lowest for S. tenacissima. Methane production (ml/g DM incubated) varied greatly. The lowest methane production was for S. tenacissima and Arthrocnemum macrostachyum (11.4 and 11.5 ml/g DM, respectively) and the highest for M. sativa and A. gombo (25.8 and 22.7 ml/g DM, respectively). The differences among species shrank when methane was expressed per ml of total gas produced or per mol of VFA produced. This indicates that a lower methane production would be due to a low fermentability of the substrate incubated, rather than to a specific inhibitory effect on methanogenesis. Hence, the 10 browse species studied herein would show little potential for mitigating ruminal methane production.

Citation

Samir MEDJEKAL , , (2018), Volatile fatty acids and methane production from browse species of Algerian arid and semi-arid areas, Journal of applied animal research, Vol:46, Issue:1, pages:44-49, Taylor & Francis

The nutritive value of Ceratonia siliqua and Gleditsia triacanthos pods was determined on the basis of their chemical composition, in vitro gas production and rumen fermentation end-products. Medicago sativa was used as a reference feed material. The studied samples showed differences in chemical composition and phenolic compounds. Crude protein (CP) content was particulary low (80 g/kg DM) in carob and higher in Medicago sativa and G. triacanthos pods with (159.79 and 121.56 g/kg DM, respectively). Inclusion of Polyethylene glycol (PEG) in fermentation medium results in a significant increase (P< 0.05) of gas production in Ceratonia siliqua and Gleditsia triacanthos and no effect was observed with M. sativa. The highest values of gas production were observed for C. siliqua and G. triacanthos, whereas Medicago sativa had significantly low values. The highest asymptotic gas production was observed in Ceratonia siliqua and Gleditsia triacanthos (296.80 and 289.55 mL g-1 DM, respectively), whereas Medicago sativa recorded the lowest value (243.64 mL g-1 DM). The concentration of acetate differentiated two groups: Medicago sativa and Gleditsia triacanthos (86.58 and 66.32% respectively), while the fermentation of Ceratonia siliqua resulted in a lower acetate concentration (59.84%). Although there were noticeable differences among the three studied samples, Ceratonia siliqua and Gleditsia triacanthos pods showed better nutritional quality, indicating that they could be considered promising and interesting sources of feed for sheep during the dry season or as supplement to low quality diets.

Citation

Samir MEDJEKAL , , (2018), Evaluation of Carob (Ceratonia siliqua) and Honey Locust (Gleditsia triacanthos) Pods as a Feed for Sheep, Evaluation of Carob (Ceratonia siliqua) and Honey Locust (Gleditsia triacanthos) Pods as a Feed for Sheep, Vol:8, Issue:2, pages:247-256, Islamic Azad University-Rasht Branch

The objective of the study was to determine the in vitro rumen fermentation end-products of 10 browse species. Serum bottles containing 500 mg of substrate, 10 ml of sheep rumen fluid and 40 ml of buffered medium were incubated for 24 h. After incubation, pH, methane and volatile fatty acid (VFA) productions were recorded. There were differences among feedstuffs (p < .05) in pH and VFA production. Astragalus gombo resulted in the highest and Stipa tenacissima in the lowest VFA production. Gas production was highest for Medicago sativa and lowest for S. tenacissima. Methane production (ml/g DM incubated) varied greatly. The lowest methane production was for S. tenacissima and Arthrocnemum macrostachyum (11.4 and 11.5 ml/g DM, respectively) and the highest for M. sativa and A. gombo (25.8 and 22.7 ml/g DM, respectively). The differences among species shrank when methane was expressed per ml of total gas produced or per mol of VFA produced. This indicates that a lower methane production would be due to a low fermentability of the substrate incubated, rather than to a specific inhibitory effect on methanogenesis. Hence, the 10 browse species studied herein would show little potential for mitigating ruminal methane production.

Citation

Samir MEDJEKAL , MOULOUD Ghadbane , Raúl Bodas, Hacène Bousseboua, Secundino López, , (2018), Volatile fatty acids and methane production from browse species of Algerian arid and semi-arid areas, Journal of Applied Animal Research, Vol:46, Issue:1, pages:44-49, Taylor&Francis

The objective of the study was to determine the in vitro rumen fermentation end-products of 10 browse species. Serum bottles containing 500 mg of substrate, 10 ml of sheep rumen fluid and 40 ml of buffered medium were incubated for 24 h. After incubation, pH, methane and volatile fatty acid (VFA) productions were recorded. There were differences among feedstuffs (p < .05) in pH and VFA production. Astragalus gombo resulted in the highest and Stipa tenacissima in the lowest VFA production. Gas production was highest for Medicago sativa and lowest for S. tenacissima. Methane production (ml/g DM incubated) varied greatly. The lowest methane production was for S. tenacissima and Arthrocnemum macrostachyum (11.4 and 11.5 ml/g DM, respectively) and the highest for M. sativa and A. gombo (25.8 and 22.7 ml/g DM, respectively). The differences among species shrank when methane was expressed per ml of total gas produced or per mol of VFA produced. This indicates that a lower methane production would be due to a low fermentability of the substrate incubated, rather than to a specific inhibitory effect on methanogenesis. Hence, the 10 browse species studied herein would show little potential for mitigating ruminal methane production.

Citation

Samir MEDJEKAL , MOULOUD Ghadbane , Raúl Bodas, Hacène Bousseboua, Secundino López, , (2018), Volatile fatty acids and methane production from browse species of Algerian arid and semi-arid areas, Journal of Applied Animal Research, Vol:4, Issue:1, pages:44-49, Taylor and Francis

Effects of three selected medicinal plants on fermentation patterns and to evaluate their potential as antimethanogenic additives in ruminant feeds were studied. Effects of Nigella sativa, Rosmarinus officinalis and Zingiber officinale, which were added to the fermentation substrate as a dry powder, on ruminal fermentation, fibre digestion and methane production, were studied in vitro in batch cultures of mixed rumen microorganisms. Serum bottles containing 500 mg of substrate (a mixture of 500 mg of alfalfa hay, 400 mg of grass hay and 100 mg of barley grain per gram), 50 mg of the plant tested and 50 ml of buffered rumen fluid (10 ml sheep rumen fluid + 40 ml culture medium) were incubated at 39 ºC for 24 h. After incubation, gas and methane production, pH and volatile fatty acid (VFA) concentration in the incubation medium and dry matter and neutral detergent fibre disappearance were recorded. The amounts of methane produced after 24 hours of fermentation varied between 0.28 and 1.12mmol/gDM. A significant methane reduction was observed with monensin (75% less methane than control) and Nigella sativa (20% less methane than control) and no effect was observed with the other treatments. Further studies are warranted to confirm the antimethanogenic activity of Nigella sativa, establish a dose-response relationship, examine the stability in time of the effects, and test if the effects can be reproduced in vivo with animals.

Citation

Samir MEDJEKAL , , (2017), Evaluation of three medicinal plants for methane production potential, fiber digestion and rumen fermentation in vitro, Energy Procedia, Vol:119, Issue:119, pages:632-641, Elsevier

Ruminants establish a symbiotic relationship with rumen microorganisms by which the animal provides nutrients and optimal environmental conditions, and microorganisms degrade fiber and synthesize microbial protein and protein supply for the animal.

Citation

SamirMEDJEKAL , ,(2017); Methane Production from Browse Species of Algerian Arid Areas,,Springer, Cham

Le présent travail a pour l’objectif d’effectuer une étude phytochimique et d’évaluer l’activité antioxydante et analgésique de la plante Mentha pulegium L. Une série de tests préliminaires a montré la présence de différents métabolites secondaires. L’extraction des polyphénols et des flavonoïdes a été réalisé par deux méthodes à savoir : Soxhlet et Markham. Les résultats obtenus ont montré que parmi les quatre extraits, l’EBr représente le rendement le plus élevé 17.16%. L’analyse de ces extraits par CCM a révélé la richesse des extraits EBr et EAc en composés phénoliques, ce qui confirme les résultats du dosage des polyphénols par la méthode de Folin-Ciocalteu, ou les teneurs sont respectivement de 180,09±12,12 et 244,38±15,48 mg EAG/g M.S. Par contre le dosage des flavonoïdes par la méthode d’Alcl3 a montré que les extraits ECh et EAc ont les teneurs les plus élevées respectivement de 41,57±1,8 mg EQ/g M.S. L’évaluation d’activité antioxydante par la méthode de DPPH a montré que les extraits polaires EBr et EAq sont les plus actifs comme des piégeurs des radicaux libres ou les IC50 sont respectivement de 24±5,65 et 22±2,82. L’activité analgésique a été testée sur des rats Wistar albinos, les résultats ont montré que la dose 100 mg/kg de la plante a un effet analgésique plus important que celui de paracétamol statistiquement significatif avec un pourcentage d’inhibition de 71,18%. Mots-clés : Plantes médicinales, Mentha pulegium L., activités biologiques, flavonoïdes, polyphénols.

Citation

Samir MEDJEKAL , , (2017), Etude phytochimique et activités biologiques d’une plante médicinale de la région de m’sila Mentha pulegium L., Revue des Régions Arides, Vol:43, Issue:3, pages:607-613, Institut des Régions Arides-Médenine-Tunisie

Les bonnes pratiques d'utilisation des animaux de laboratoire

Citation

Samir MEDJEKAL , ,(2017), Les bonnes pratiques d'utilisation des animaux de laboratoire,Les bonnes pratiques d'utilisation des animaux de laboratoire,Université Mohamed boudiaf-M'sila

Dans ce travail, nous nous sommes intéressés à évaluer l’effet de la saison de collecte sur la valeur nutritive et la production de méthane et de tannins condensés par le microbiote d’ovins en présence d’Astragalus gombo (ASGO), prélevé d’une région semi-aride d’Algérie. On observe des variations significatives (p < 0,05) entre les trois saisons dans tous les composants chimiques d’ASGO, sauf en tannins condensés liés aux protéines. La plante présente des valeurs de protéines brutes (PB) très variables. Le taux le plus faible de PB est noté chez ASGO collecté en été avec une valeur de 166±2 g/kg MS, et la valeur la plus élevée chez ASGO prélevé en hiver (285±14 g/kg MS). De faibles teneurs en tannins condensés totaux sont enregistrées avec de faibles variations d’une saison à l’autre. Globalement, les tannins varient de 19,0 ±0,6 à 24,2±0,6 (g/kg MS). ASGO prélevé durant l’hiver et l’été est le plus producteur de gaz, avec 68,5±24,5 et 70,3±22,5 ml/g MS respectivement. Il est suivi de ASGO au printemps avec 50,8±21,1 ml/kg MS. ASGO, par sa richesse en protéines brutes et ses faibles teneurs en lignine, montre un bon potentiel nutritif pour les ruminants des zones arides, soit en pâturage libre sur les parcours pastoraux, ou bien en complémentation des rations riches en fibres. On peut donc constater que, malgré les caractéristiques exceptionnelles d’adaptation de la flore spontanée saharienne aux conditions climatiques très rudes de leur milieu désertique, il est évident que la survie, le développement et la composition chimique de ces plantes dépendent étroitement des variations climatiques. Mots-clés: Algérie, alimentation, production de gaz in vitro, ruminant, wilaya de M’sila

Citation

Samir MEDJEKAL , , (2016), Effets de la saison de collecte sur la valeur nutritive et la production de méthane et de tannins condensés d’Astragalus gombo, Livestock Research for Rural Development, Vol:28, Issue:12, pages:1-9, Published by Fundación CIPAV, Cali, Colombia Centro para la Investigación en Sistemas Sostenibles de Producción Agropecuaria, Cali, Colombia

Cette thèse avait pour objectifs principaux l’étude, dans une première partie, de l’effet de la saison de collecte sur la valeur nutritive, la teneur en tannins et la production de méthane de trois arbustes fourragers locaux : Atriplex canesens, Astragalus gombo et Calobota saharae, prélevés d’une zone aride d’Algérie sur trois saisons consécutives. Le travail a consisté à caractériser divers paramètres : la composition chimique des plantes, l’évaluation de leur potentiel nutritif par la mesure de leur fermentescibilité et leur digestibilité in vitro. Dans une deuxième partie, un essai de réduction de la méthanogénèse ruminale in vitro a été testé en présence de trois plantes médicinales locales : Nigella sativa, Rosmarinus officinalis.L et Zingiber officinale. Les paramètres étudiés sont : le profil de la fermentation ruminale, la production de gaz totaux, la production de méthane et la digestibilité, de même que leur impact sur la production quantitative et qualitative d’acides gras volatiles. L’analyse chimique révèle que la saison de collecte a un effet significatif sur tous les composants chimiques des trois arbustes étudiés, sauf en tanins condensés. Atriplex canescens détient une teneur très élevée en protéines brutes durant l’hiver qui atteint 200g/kgMS. Concernant sa teneur en constituants pariétaux, elle est très élevée en hiver et au printemps, par rapport aux valeurs d’été. Les mêmes variations en composition chimique sont enregistrées pour Astragalus gombo, contrairement à Calobota saharae dont les teneurs sont très élevées en été par rapport à l’hiver et au printemps. Cette situation est probablement due aux conditions climatiques qui règnent dans la région de M’sila, caractérisée par des températures élevées et une faible pluviométrie. Du point de vue chimique, les variations temporelles démontrent que l’effet saison sur les différents résultats obtenus est significatif. Cet effet s’exerce par les variations climatiques qui lui sont associées. En effet, est enregistrée une variabilité nette pour la teneur en matière azotée totale et en constituants pariétaux. Malgré les caractéristiques exceptionnelles d’adaptation de la flore spontanée saharienne aux rudes conditions du milieu, il est évident que sa survie, sa prolifération et sa composition chimique dépendent étroitement des variations climatiques. Cette étude a des implications pratiques pour le développement des technologies agro-forestières. Les trois plantes étudiées ont un bon potentiel comme arbustes fourragers pour les projets de réhabilitation des écosystèmes dégradés dans les zones arides et semi-arides. Les plantes médicinales représentent une source naturelle de molécules bioactives qui peuvent modifier positivement la fermentation ruminale. Une réduction significative de la production de méthane est observée avec le Monensin. Pour ce qui est du Nigella sativa, il est établi que cette plante est très riche en lipides et en stérols, cet état pourrait être à l’origine de son action anti-méthanogène. Quant aux autres traitements testés, ils sont sans effet.

Citation

SamirMEDJEKAL , ,(2016); Effet de la saison de collecte sur la valeur nutritive, la production de méthane et de tannins condensés d’arbustes fourragers locaux. Essai de contrôle in vitro de la méthanogénèse ruminale d’ovins par l’utilisation de plantes médicinales.,Université Mentouri Constantine 1,

The current trial was conducted to study the effect of season on the potential nutritive value, methane production and condensed tannin of Calobota saharaeshrub harvested at three different seasons, in winter (mid-January), spring (mid-May) and summer (end of July). Leaves, thin twigs, some flower and seeds (when existing) were clipped with scissors fromthe aerial part of the plants then dried and analysed for chemical composition. Gas and methane production were determined at 24 h incubation time. Season of harvest had a significant effect (p <0.05) on the chemical composition, gas production and in vitrodigestibility of Tilley and Terrybut no effect on metabolisable energy. Neutral detergent fibre (NDF), Acid detergent fibre (ADF) and acid detergent lignin (ADL) of Calobota saharaewere high during summer (dry season) and low in spring and winter (wetseason). The NDF, ADF and ADL contents ranged from 463.05 to 616.82 and 352.27 to 488.21 and 121.19 to151.73 (g/kg DM) respectively. The CP content was lower (p <0.05) in summer (96.84g/kg DM) versus spring (138.85 g/kg DM) and winter (139.42g/kg DM). Thegas and methane production at 24 h incubation varied between 65.75 to 77.75 and 6.50 to 10.17 (ml/g DM) respectively and decreased significantly (p <0.05) from spring to summer. In conclusion, season had a significant effect on the nutritive value of Calobota saharaeshrub.Calobota saharaeshould be grazed or harvested during winter and spring since these seasons provide this shrub with high ME and CP content for ruminant.

Citation

Samir MEDJEKAL , , (2015), Impact of season of harvest on potential nutritive value, methane production and condensed tannins content of calobota saharae in msila, north-central Algeria, J. Polish Agric. Univ, Vol:18, Issue:2, pages:1-9, Copyright © Wydawnictwo Uniwersytetu Przyrodniczego we Wroclawiu, ISSN 1505-0297

Methane (CH4) emitted from ruminant livestock is regarded as a loss of feed energy and also a contributor to global warming. Methane is synthesized in the rumen as one of the hydrogen sink products that are unavoidable for efficient succession of anaerobic microbial fermentation. Strategies for reduction of methane emissions from the rumen have been proposed, mainly through rumen microbial manipulation, by the use of agents including chemicals, antibiotics and natural products such as oils, fatty acids and plant extracts. A more recent approach is the development of vaccines against methanogenic bacteria. While ionophore antibiotics have been widely used due to their efficacy and affordable prices, the use of alternative natural materials is becoming more attractive due to health concerns regarding antibiotics. It was concluded that the most promising areas for future research for reducing methanogenesis are the development of new product/delivery systems for antimethanogenic compounds in the rumen and reduction in protozoan numbers in rumen. Whatever the approach proposed, however, before practical solutions are applied in the field, the sustainability of CH4 suppressing strategies is an important issue that has to be considered. The evaluation of different strategies, in terms of total greenhouse gas emissions for a given production system, is discussed.

Citation

Samir MEDJEKAL , , (2015), Strategies to Mitigate Methane Emissions during the Digestive Process in Ruminants: A review, Australian Journal of Basic and Applied Sciences, Vol:9, Issue:27, pages:9-18, Australian Journal

The current trail was conducted to study the effect of season on the potential nutritive value, methane production and condensed tannin of Atriplex canescens sampled at three different seasons (winter, spring and summer). Gas and methane productions of Atriplex canescens were determined at 24 h incubation time. Season of sampling had a significant effect (p <0.05) on the chemical composition, gas production, methane production, metabolizable energy and in vitro dry matter digestibility of Telly and Terry. The CP content was lower in spring (167.68 g/kg DM) and summer (171.08 g/kg DM) versus winter (200.89 g/kg DM). In winter and spring, Atrilplex canescens had higher (p <0.05) NDF, ADF, ADL and HCL contents than in summer. In all the seasons, condensed tannins and EE content were generally low, whereas the ash content was extremely high (p <0.05) with (243.8 g/kg DM) in spring and (197.3 g/kg DM) in winter. Sampling season had a significant effect on the nutritive value of Atrilplex canescens. Its nutritive value decreased in spring and increase in summer and winter. Atrilplex canescens should be grazed or harvested during winter and summer since these seasons provide this shrub with high ME and CP content for ruminant.

Citation

Samir MEDJEKAL , , (2015), Effect of Season on Potential Nutritive Value, Methane Production and Condensed Tannin Content of Fourwing Saltbush (Atrilplex canescens), Global Veterinaria, Vol:14, Issue:2, pages:166-172, International Digital Organization for Scientific Information (IDOSI)

The nutritive value of some Algerian browse species was studied on the basis of their chemical composition, in vitro gas production and fermentation kinetics (gas production technique). The browse species were Stipagrostis pungens, Lygeum spartum L. and Stipa tenacissima L. Generally, there were significant variations P< 0.05 between chemical components of all browse species studied herein, except in condensed tannins (CT) content. The organic matter (OM) contents varied with a narrow range from 843.52 to 867.87 g/kg DM. The crude protein (CP) content value of the edible components ranged between 47.06-75.20 g/kg DM, the highest CP value was recorded for Lygeum spartum L. The Neutral detergent fiber (NDF) and ADF contents were relatively high P< 0.05 in Stipa tenacissima L. and low in Lygeum spartum L. The total gas production and organic matter digestibility (OMD) ranged from 56.49 to 91.15 (ml/g DM) and 38.15 to 59.03%, respectively. Generally, high values of gas production and Organic matter digestibility OMD were recorded by Lygeum spartum L. followed by Stipagrostis pungens. As conclusion, browse species evaluated in the present study show high content of fiber and low crude protein concentration. Nitrogen supplementation and effects of alkaline treatments are then expected to be highly beneficial for in vitro organic matter digestibility, as observed in more conventional low quality forages.

Citation

Samir MEDJEKAL , , (2015), Chemical Composition and in vitro Gas Production of Three Local Poaceaes in El Djelfa’s Region, North-Central Algeria, World Applied Sciences Journal, Vol:23, Issue:2, pages:271-277, International Digital Organization for Scientific Information (IDOSI)

The main objective of this study is assessing the nutritive value of agricultural by-products dry palm leave, Aristida pungens in comparison to barley straw by chemical analysis, rumen fermentation characteristics and gas production technique in vitro. A quantitative analysis of gases produced from dry palm leaves was compared to that of Drin and barley straw which are common feeds in the semi arid and arid regions of Algeria. The results obtained show that the activity of goats’ rumen microflora is very important on the studied substrate of the arid regions, which indicates very significant digestibility coefficient. This situation is certainly due to the high content of barley straw of total soluble sugars and thus more easily fermentable. For dry palm leaves, the value of in vitro gas digestibility is 49.8 ℅. It is close to that of Drinn, probably owing to the fact that these substrates present almost the same level of lignin and of cellular wall contents. These results suggest a high potential of integrating dry palm leaves in ruminants’ feed in these areas leading to overcoming the problems of maintaining feed supply. Key words: Drinn, goats, dry palm leaves, in vitro gas production, rumen microflora

Citation

Samir MEDJEKAL , , (2011), Nutritive value assessment of some desert by-products by gas production and rumen fermentation in vitro, Livestock Research for Rural Development, Vol:23, Issue:3, pages:1-9, Published by Fundación CIPAV, Cali, Colombia Centro para la Investigación en Sistemas Sostenibles de Producción Agropecuaria, Cali, Colombia

la Proteine": "Production et Purification des protèines recombinantes chez E.Coli"

Citation

Samir MEDJEKAL , ,(2009), la Proteine": "Production et Purification des protèines recombinantes chez E.Coli",Atelier de formation N° 1 "Du gène à la Proteine": "Production et Purification des protèines recombinantes chez E.Coli",Université Mentouri Constantine

TRANSFERT ALGERIE: Creation et Gestion d'un Enseignement Ouvert et Distant

Citation

Samir MEDJEKAL , ,(2008), TRANSFERT ALGERIE: Creation et Gestion d'un Enseignement Ouvert et Distant,TRANSFERT ALGERIE: Creation et Gestion d'un Enseignement Ouvert et Distant,Université Mentouri de Constantine

Formation aux premiers secours

Citation

Samir MEDJEKAL , ,(2007), Formation aux premiers secours,Formation aux premiers secours,Croissant rouge Algerien -Direction de soucourisme wilaya de Mila

Notre travail a pour but l’étude de l’activité fermentaire in vitro de la microflore ruminale des caprins vis à vis des sous produits d’agronomie saharienne :les palmes sèches, le Drinn ainsi que la paille d’orge prise comme substrat standard de référence, notre indicateur de fermentation est la production de gaz. Les résultats d’étude quantitative et qualitative du pool gazeux ont montré que les palmes sèches autant que sous produit d’agronomie produisent un pool gazeux abondant et diversifier et comparable à celui du Drinn .Mais inférieur à celui de la paille d’orge. Le Washing losses de différents substrats obtenue par la méthode des filtre révèle que la fraction pariétale des trois substrats est lentement dégradée comparativement à leurs substrat brut et nécessite un temps de latence plus ou moins élevé requit pour l’adaptation de la microflore ruminale à la synthèse d’enzyme responsable. Un cas particulier est signalé après l’étude de la fermentation de la fraction pariétale du palmes sèches, où on assiste à une amélioration du pool gazeux total. Cela indique clairement que les palmes sèches contient des substances indésirables voir toxiques à la microflore ruminale et leur lavage à l’eau distillée a permit l’amélioration de la production de gaz totale issue de la fraction pariétale, donc le Washing losses s’avère utile pour l’étude de la fermentation des parois végétales et parfois détecte la présence des substrats indésirables.

Citation

SamirMEDJEKAL , ,(2003); Etude de la fermentescibilité in vitro de sous produits de l’agronomie saharienne par la microflore ruminale de caprins. Utilisation de la technique du Washing loss pour la détermination de la dégradation spécifique des fractions pariétales des substrats.,Université Mentouri Constantine 1,