Screening of probiotic potentiality of lactobacilli strains, isolated from fermented bamboo shoots of assam.

Abstract

Lactic acid bacteria were isolated from collected samples of fermented bamboo shoot of two different species of bamboo from distinguished communities of Namrup, Dibrugarh district of Assam. Pure culture and biochemical characterization of the isolated LAB were done which were grown on De Man Rogosa and Sharpe Agar medium. Probiotic characteristics of isolated lactobacilli were tested by NaCl tolerance and in-vitro studies of gastro-intestinal performance by applying the acid tolerance (pH 3) and bile salt tolerance(0.3% ox gall) test, that was evaluated through observing the viable counts after grown on MRS Agar and measuring the absorbance spectrophotometrically at 600nm. A total of eight lactobacilli were primarily isolated based on their negative result of catalase test and absence of any spores. They were further investigated for the utilization of nine types of sugar, based on which isolates are biochemically screened out as Lactobacillus plantarum, Lactobacillus brevis and Lactobacillus helveticus. This experimental result also facilitated with the test of API 50 CH (bioMerieux). In the study of in vitro gastrointestinal performance it shows that out of the 8 isolated LAB, Lactobacillus plantarum that we have screened shows good tolerance to pH 3 having survivability difference in comparison to control is less than 0.14 in log of CFU/ml, which also shows reduction in cell viability less than 0.14 log unit after growing in 0.3% bile containing MRS medium. The isolated all Lactobacillus brevis and Lactobacillus helveticus indicates poor growth in MRS medium of pH 3 but, all the three Lactobacillus brevis shows good tolerance to bile. The isolated Lactobacillus helveticus only shows the growth at the pH 4.5- 6.5, which is also not tolerate 0.3% bile (ox gall) containing medium.