The selection oftherraotolerant lactic acid bacteria and applications for lactic acid production

Abstract

This study aimed to select thermotolerant lactic acid bacteria for the production of lactic acid. As a result, among 54 bacterial strains screened for lactic acid fermentation at 37°C, 16 strains were selected due to their significantly higher fermentation ability. The molecular sequencing and NCBI aligning evidences proved that the selected strains belonged to Lactobacillus delbrueckii, Lactobacillus casei, and Lactobacillus plantarum. Of which, Lactobacillus casei L9 showed the good acid production at 37°C (12.9 g/l), 39°C (18.9 g/l), and 41°C (18 g/l). In the fermentation test at one- liter scale by using L. casei L9 with the favourable conditions (pH 6.53, 6% (w/v) of glucose, 2.33% (v/v) of 10⁷ cells/ml starter), the fermentation yield could reach the 80.84% efficiency.