Isolement et identification biotechnologique des souches de Leuconostoc

Abstract

Lactic acid bacteria are known for their ability to produce active compounds during growth, i.e. organic acids that acidify the environment, and their use for a given industrial application is determined by their functional and technological properties. Leuconostocs are Gram-positive, catalase-negative, non-pathogenic, acid-tolerant lactic acid bacteria, making them the third genus of lactic acid bacteria. In this study, 8 strains of Leuconostoc were isolated from four Milk origins (cow, ewe, goat and Camel). After isolation, the strains were characterized and identified by classical morphological, physiological and biochemical tests to identify the genus, then tested for their technological potential: proteolytic activity, production of exopolysaccharides (dextran), antibacterial power against pathogenic bacteria: E. coli ATCC 2592, S. aureus ATCC 25923, Pseudomonas aeruginosa ATCC9027 and sugar degradation, arginine hydrolysis, etc. The results show that all strains have interesting technological characteristics: production of exopolysaccharides (EPS), high proteolytic power, arginine hydrolysis, sugar degradation, antibiotic resistance and inhibitory power against the pathogens used.