Résumé
Twenty-six typical heterofermentative strains of Lactobacillus spp. isolated from Aswanese grape vines were identified with the aid of API 5O CHI system and by the analysis of the computerized comparative data of their total soluble cell protein patterns using the polyacrylamide gel electrophoresis technique. Ten strains were identified as Lactobacillus hiulgardii, eight as L. brevis, five as L. buchneri, two as L. Viridescens and only one strain as L. cellobiosus. Three strains of L. buchneri, four of L. hiulgardii, two of L. Brevis and one strain of L. viridescens produced H2S in peptone water supplemented with 0.01% cysteine. All strains produced mannitol from fructose and thus described heterofermentative lactic acid bacteria. Proteolytic activity was detected in all strains capable of digesting gelatine and also hydrolyzed casein. All strains except those of L. Viridescens decarboxylated L-malic acid to L-lactic acid
Résumé
Twelve strains of thermophilic fungi isolated from mud and water samples of Aswan High Dam Lake [AHDL] were screened for their lipase[s] production. Four strains exhibited the highest lipolytic productivities, thus chosen for studying some factors affecting lipase[s] productivities. Maximum lipase[s] productivities simultaneously with mycelial dry weights were recorded for the four strains on 6th day of incubation at 45 degrees. Lack of lipid material in the production medium did not inhibit lipase[s] synthesis which refers to their constitutive nature. The present fungal lipases were able to hydrolyze both natural and synthetic glycerides. They were particularly active within a temperature range of 45-50 degrees and a pH range of 5.5-6.5. The involvement of the present fungi in the formation of milk products, butter flavors in food products and even in spoilage of groundnuts during storage is suggested