http://depot.umc.edu.dz/handle/123456789/10154 Thu, 30 Apr 2026 14:11:12 GMT 2026-04-30T14:11:12Z http://depot.umc.edu.dz/handle/123456789/10213 Isolement de souches bactériennes potentiellement productrices de lipases alcalines, à partir du beurre cru et du beurre fermenté « Dhan ». Belhoula, Nora; Bekhouche, Farida Considerable interest is carried currently for lipase, mainly to industrial sectors, as well as for the lipolytic flora of the local traditional products. In this context, settles the goal of our work on isolation of lipolytic strains from raw butter and smen, which are two traditional Algerian dairy products. As well as the screening of the best bacterial isolates producing lipases. To achieve our goals, six samples of varied origin were used for the physicochemical analysis and the isolation of lipolytic bacterial strains. We used several media, all these are supplemented with Of egg yolk or olive oil and / or Tween 80. The strains obtained are classified for its activities on agar medium and then grown on Liquid media. Titration is the method used to estimate free fatty acids or lipase activity. Physicochemical characterization results showed that there was a significant difference between the measured parameters of butter and smen samples. Screening yielded to obtaining of several lipolytic isolates from raw materials rich in fat, namely : raw butter and smen. The test of the lipolytic activity has allowed selecting Forty-nine bacterial strains which are approximated on the basis of the phenetic results of six types : 49% (24) are Gram-positive, Branched filamentous, catalase positive, asporulated and immobile ; 31% (15) are Gram-positive, cocci, catalase positive, asporulated, immobile and degrade mannitol ; 10% (5) are Gram-positive, rod, catalase positive, asporulated and immobile ; 4% (2) are Gram-positive, cocci, Catalase positive, asporulated, immobile, does not degrade mannitol and have a yellow color ; 4% (2) are Gram-positive, rod, catalase positive, sporulated and mobile and 2% (1) are Gramnegative, cocci, catalase positive, asporulated and immobile. The test of production of lipase on liquid medium containing inducers of the production of the enzyme (Tween 80, olive oil with or without Tween 80) yielded to the selection of eight strains (SG (5, 8, 9, 14, 25, 26 ) ; BG (32) ; SS (46)), potentially producing true lipases independently of the nature of the lipid source. This finding reveals the degree of adaptation of these strains to various media, giving it various biotechnological applications. Thu, 09 Mar 2017 00:00:00 GMT http://depot.umc.edu.dz/handle/123456789/10213 2017-03-09T00:00:00Z http://depot.umc.edu.dz/handle/123456789/10212 Viande cunicole; situation de l’élevage dans l’Est algérien, comparaison des paramètres physico chimiques, biochimiques, etsensoriels de la race Néo-Zélandaise et la population locale « El Arbia » Sanah, Ibtissem; kharroub, Karima The first objective of this research was to study the situation of the cunicultural sector in eastern Algeria by launching a survey with herders, butchers and consumers, the second objective being the comparison of morphological, physico-chemical, biochemical and sensory parameters determining the quality of the meat for the local Algerian breed ""El Arbia"" and the ""New Zealand"" foreign breed. To reach our objectives, a survey was carried out among 80 breeders, 32 butchers and 360 consumers across 15 towns in eastern Algeria. The main results of the survey show that rabbit farms are concentrated mainly in Mila, Setif, Bordj Bou Arreridj, and Constantine. The situation of cuniculture has been judged to be continuously evolving, but several constraints hinder its development. As for butchers, rabbit meat is considered among the most expensive meats. Concerning consumers, rabbit meat is as appreciated as that of broilers. But its frequency of consumption is low. Thirty rabbits (15/15) of the two breeds were used for the extraction of the muscle Longissimus dorsi (LD), for the analysis of the physicochemical and biochemical parameters as well as the instrumental measurement of tenderness at Penetrometer. While the thighs were taken for use in sensory analysis, and muscle weight loss. Comparison of morphological, biochemical and physico-chemical parameters revealed the following main results: The breed factor has significantly affected slaughter yields, muscle weight loss, as well as the juiciness of the meat, and also morphological parameters such as: length Total, length of the loins ... at 5% threshold An identical pattern of fall in temperature, pH, water holding capacity, cooking losses, myofibril fragmentation index, the profile of penetration depth, the electrophoretic characterization (SDS-PAGE) of sarcoplasmic and myofibril proteins The results obtained morphologically confirm the defects of the local population; on the other hand, the quality of the meat seems to be very interesting organoleptically and technologically. Wed, 15 Mar 2017 00:00:00 GMT http://depot.umc.edu.dz/handle/123456789/10212 2017-03-15T00:00:00Z http://depot.umc.edu.dz/handle/123456789/10211 Mise en évidence des activités hydrolytiques extracellulaires de microorganismes halophiles et halotolérants des environnements hypersalins sahariens. Bouras, Biya; Kharroub, Karima Halophilic and halotolerant microorganisms in hypersaline environments have developed strategies to adapt to environmental constraints. They thus present original biomolecules, in particular enzymes which enable them to develop optimally in their biotopes. The exploitation of these microorganisms and their molecules is a boon for biotechnology. The objective of this study is to demonstrate extracellular hydrolytic activities in halophilic and halotolerant microorganisms of sebkha Melghir and chott Merouane (wilaya of El Oued), and chott Aïn El Beida (wilaya of Ouargla). This work resulted in the isolation of seventy-two strains from brine and sediment samples. A preliminary characterization based on cultural, morphological, biochemical and physiological aspects is carried out. 29 pigmented, Gram-negative and extreme halophilic strains (optimum at 20% (w/v) salt) possess the properties of haloarchaea. The remainder of the isolates are distributed between moderate halophiles and halotolerants, and often Grampositive. The spherical cellular form is predominant. All strains have a broad growth temperature range with an optimum at 37°C or 45°C; They are moderate mesophiles or thermophiles. About 50 strains have extracellular hydrolases, dominated by the hydrolysis capacity of gelatin. However, amylolytic activity appears to be more important in strains of Archaea. In addition, many isolates produce up to four types of hydrolases. Thu, 15 Dec 2016 00:00:00 GMT http://depot.umc.edu.dz/handle/123456789/10211 2016-12-15T00:00:00Z http://depot.umc.edu.dz/handle/123456789/10209 Effet des procédés technologiques (industriel et artisanal) sur quelques antioxydants de la conserve Harissa. Djabali, Saliha; Barkat, Malika The aim of this study is the evaluation of antifungal activity of polyphenols extracted from two varieties of dry bean, presenting white (Tima) and red (MGT djedida) color. Determination of moisture for the two varieties showed that these grains are favorable for moulds growth. Purification and microscopic study of the isolated stocks allowed the identification of 6 moulds genera: Alternaria, Aspergillus, Moniliella, Fusarium, Penicillium and Rhizopus. Extraction of total polyphenols was carried by a polar solvent and their quantification was based on the reaction of Folin Ciocalteu. The total polyphenolic content was 0,40±0,005 mg EAG/g for the red variety and 0,27±0,005 mg EAG/g for the white variety. The antifungal activity carried by the methods of direct contact, dilution, and antifungal index (IA100) made possible to prove the antifungal capacity of polyphenols, most sensitive stocks are Alternaria sp., Moniliella sp. and Rhizopus sp.. The most active polyphenols are the red healthy bean polyphenols. Among this study, we can show that the promising results obtained incent creation of varieties with high percentage of polyphenols, preservative, bio-effective and natural agents, which can be an alternative solution for chemical agents used for the protection of harvests in storage structures. 134 f. Sun, 01 Jan 2012 00:00:00 GMT http://depot.umc.edu.dz/handle/123456789/10209 2012-01-01T00:00:00Z