Research on Screening and Physiological Characteristics of Preferable Lactic Acid Bacteria from Fermented Lotus Sprout

In this experiment,using the aquatic vegetable lotus sprout as raw material,two strains were isolated and screened from the natural fermentated lotus sprout pickle juice,which possessed the excellent characteristics of strong capability of acid production,low nitrite content and pleasant fermentation flavor,and they were identified as Lactobacillus plantarum and L.brevis by physiological and biochemical tests.The optimal pH value of the two strains was 5.0 to 6.0. L.brevis could grow well when the pH value was 3.0,but its growth was inhibited when the pH value was higher than 8.0.L.plantarum grew slowly when the pH value was 3.0,but it was still surviving to some extent when the pH value was higher than 9.0.Both the strains could grow normally when the salt concentration was below 6%,but their growth was restrained when the salt concentration was 10%.L.plantarum was tolerant of salt concentration of 8%.The two strains had considerably wide temperature tolerance,with the temperature ranged from 20℃ to 37℃,and the optimal temperature was 30℃,but they could grow slowly when the temperature was 15℃.L.plantarum and L.brevis depleted 89.65% and 97.40% nitrite in Man Rogosa Sharpe broth cultural medium,and the initial nitrite content of the cultural medium was 100 μg/mL.