Isolation and identification of Lactobacillus casei in tofu acid pulp and its application as tofu coagulant

A strain of lactic acid bacteria was screened out from the tofu acid pulp by the plate coating method and high performance liquid chromatography with the p H and lactic acid yield as indexes. The morphological observation, colony morphological observation, physiological and biochemical identification and 16S rDNA sequence analysis of the strain were carried out, and the results showed that the lactic acid bacteria belonged to Lactobacillus casei. The isolated Lactobacillus casei YQ336 was inoculated into bean curd water and fermented into tofu coagulant to make tofu, compared with tofu made from natural fermented acid pulp, it was found that there was no significant difference between the two sensory scores ( p > 0.05) .The result indicated that Lactobacillus casei YQ336 can be developed and used as a new tofu coagulant.