Isolation and identification of cholesterol-reducing lactic acid bacteria from indigenously fermented pickles and dried-sausage

Abstract:

Abstract: [Objective] To obtain cholesterol-reducing lactic acid bacteria (LAB), we isolated and identified strains of LAB from indigenously fermented pickles and dried-sausage. [Methods] We screened original LAB strains based on the Calcium Carbonate-MRS medium (Calcium Carbonate-Man Rogosa and Sharp Medium) from pickles and sausage. The cholesterol-reducing strains were confirmed by screening with in vitro cholesterol levels. These strains were identified by methods of morphologic observation, catalase reaction, carbohydrate reaction and 16SrRNA sequencing. [Results] We obtained two strains of LAB (LpT1 and LpT2), which presented a comparatively high ability of cholesterol reducing. The two strains also showed high acid resistance and bile salt tolerance. The time of LpT1 entering the logarithm phase of growth and stationary phase of growth was 14 hours and 22 hours after cultivated, while that of LpT2 was 12 hours and 20 hours after cultivated. These two strains survived for at least 4 hours in the MRS broth with pH 2.0 and grew well in the MRS broth containing 0.2% bile salt, and we identified these two strains to be Lactobacillus plantarum by 16SrRNA sequencing. [Conclusion]The two LAB strains could reduce cholesterol in vitro and resist acid and bile salt.

Key words:Keywords: cholesterol reducing; lactic acid bacteria; 16S rRNA; identification