Isolation of exopolysaccharides producing lactic acid bacteria from dairy products

Abstract

Currently, much attention is being paid for improving the texture of food by screening the new exopolysaccharides (EPS) producing strains. The aim of the present work was to isolate EPS producing Lactic acid bacteria (LAB) strains from raw milk and milk products samples. Total of thirty eight dahi, lassi and raw milk samples were collected from different villages and towns of Karnal and Delhi District. The samples were plated on milk agar and colonies showing ropy polysaccharides production were subjected to biochemical test. After molecular identification 2 were found as S. thermophilus, 2 were Lb. rhamnosus and 2 were confirmed as Lb. fermentum. Two S. thermophilus strains (PD7 and PD11) and Lb. fermentum strains (AL6 and AD3) showed better curdling pattern, acidity, exopolysaccharides production, and sensory properties. These cultures can be used for manufacture of indigenous fermented milk products.