A Study on Isolation and Identification of Exopolysaccharide (EPS) producing Bacteria from Soil

Abstract

Polysaccharides are important potent molecules with their structural and compositional complexity which led to wide range of applications in various industries. The exopolysaccharides of microbial origin are released in response to extreme environmental conditions for the purpose of survival. The present study focuses on the isolation of exopolysaccharide producing bacteria from the soil sample and oil contaminated soil sample. Screening for the EPS production by the isolates is determined by the dry weight determination of precipitates of EPS and quantitative estimation of glucose content of EPS by PhenolSulphuric acid method. In the present study, out of 5 bacterial isolates isolated on screening, Lactobacillus sps and Pseudomonas sps. isolates produced the precipitates of EPS whose dry weight was determined to be 0.09g and 0.17g respectively. Further, glucose concentration of EPS was quantitatively determined. The glucose content of Lactobacillus sps. isolate was 0.1125mg/ml and Pseudomonas sps. isolate is 0.2875mg/ml. The EPS producing isolates were further grown in the presence of carbon sources like Glucose, Lactose, Maltose and Sucrose to determine the best utilizable carbon for their growth. The most utilizable carbon source for maximum growth of EPS producing isolates was determined to be sucrose with 2% concentration. All the 5 bacterial isolates were screened for their ability of antibiotic resistance. The EPS producing isolates, Lactobacillus sps, Pseudomonas sps were found to be resistant towards all the antimicrobial agents owing to the presence of EPS protective layer around their cell wall than non-EPS producing isolates. Keywords: Exopolysaccharide, Screening, Carbon sources, Antibiotic resistance.