Study on growth characteristics of lactic acid bacteria from the acid slurry bean curd of Yunnan Jianshui

To screen the suitable lactic acid bacteria fermentation acid whey,the growth curve,acid production,acid tolerance and osmotic pressure tolerance ability of five lactic acid bacteria which isolated from tofu acid whey of Yunnan Jianshui acid slurry bean curd were compared. The results of growth curve experiment showed that the strain SYG02 had the strongest reproductive capacity,followed by the strain SYG03,and the growth rates of strains SYG05,SYG04,SYG01 were significantly slower. SYG02 produced the most acid within the least time,followed by SYG03,SYG05 and SYG04,and SYG01 was the weakest. All of the five strains could well-grown at the condition of pH4.0,and could survive at the condition of pH3.0,while the total plant counts were only 10²~10⁴ CFU/mL,SYG02 and SYG03 showed better acid resistance than other three strains. In terms of osmotic tolerance,SYG02 showed strong tolerance to 8%(w/V)NaCl,the growth of the other 4 strains was inhibited obviously when the content of NaCl was more than 6%(w/V). A conclusion was drawn from the comparison of the pH and acid production of the fermentation tofu whey that the acid producing ability of mixed strains was better than single strain that the acid producing ability of mixed strains was better than single strain,the strain SYG02 and SYG03 had the best effect on fermentation tofu whey,after 72 h fermentation tofu whey pH was 3.52,acid production reached 6.46 g/L. Accordingly,SYG02 has good abilities of producing acid and resisting osmotic pressure,the strain have a good application potential and can play an important role for the commercial process of acid slurry bean curd.