Isolation of Exopolysaccharides producing bacteria collected from fish pond in Ba Ria Vung Tau province.

Abstract

The objectives of this study were to isolate exopolysaccharide (EPSs) producing bacteria from different sample types collected from several fishponds in Ba Ria Vung Tau province, and morphologically and chemically classified them. From 24 samples, 13 EPS producing bacteria were isolated. The obtained results showed that biofilm and submerged wood samples provided larger numbers of EPS producing bacteria compared with mud and water samples. Morphological and chemical characterization showed that Bacillus was the most abundant genus among the EPS producing bacteria isolated and Bacillus cereus was found to produce highest amount of EPS (0.56g/L). The identification of this species was confirmed by 16S rRNA analysis by Nam Khoa-Biotek Co., Ltd. Effects of EPS producing bacteria (B. cereus) on probiotic bacteria (L. acidophilus) was also investigated by comparing cell growth (log CFU/mL) of L. acidophilus in its pure culture and in mixed culture of it with B. cereus. The obtained result revealed that B. cereus could enhance growth of L. acidophilus.

Key words: Bacillus, exopolysacchrides, fishpond, identifification, isolation