Etude de la bioprospection de levures : criblage des activités enzymatiques d’intérêt biotechnologique.

Abstract

In this study, we focused on the isolation and selection of yeast strains that produce enzymes of iotechnological interest. Isolation was performed from four samples: cow's milk, whey curd, and potato peel. These microbial niches allowed the isolation of 7 strains on YPG. The identification of the 7 selected strains was carried out through the study of morphological and physiological characteristics.A macroscopic study was conducted to determine the cultural characteristics of the isolated yeast strains, and a microscopic study was performed to determine their shape and size. Different carbon sources such as lactose, maltose, sucrose, and galactose were used for physiological identification through fermentation. For nitrogen assimilation, nitrogenous ubstrates including glutamic acid, alanine, tryptophan, and potassium nitrate (KNO3) were used. The enzymatic potential of the studied isolates was evaluated for the production of 4 different enzymes by culturing microorganisms on different substrates. The enzymes studied were alpha-amylase, pectinase, maltase, and protease. The results showed that all selected strains produce the mentioned enzymes, except for strain S5, which does not produce maltase and pectinase