The Investigation Of Microbial Diversity In Stinky Tofu Brine

The microbial diversity in Stinky Tofu brine was investigated by the traditional microbial identification methods combined with modern molecular biological techniques. What's more, the enzyme production capacity of the microbial isolated from the Stinky Tofu brine and the lactic acid production capacity of lactic acid bacteria were approved.Six bacteria were isolated from the Stinky Tofu brine, which were identified as the: Bacillus subtilis, Bacillus pumilus, Bacillus licheniformis, Bacillus marinus, and Acinetobacter lwoffii. Bacterial diversity was analyzed by restriction fragment length polymorphism (RFLP) of 16S rRNA gene, and fourteen genotypes were gotten, which were sequenced and compared by BLAST with sequences in the Genbank. Three strains are beneficial Lactobacillus. The bacteria diversity of Stinky Tofu brine was demonstrated comprehensively.The changes of bacterial diversity on season in Stinky Tofu brine were analyzed by traditional microbial identification methods and denatured gradient gel electrophoresis, which indicate that the bacterial diversity in summer and autumn was more plenty than that in winter and spring. Four strains could not be identified by 16S rDNA, were identified by the API test strips. Three are Bacillus inactive type, one is Bacillus cereus.Seventeen fungi were isolated from Stinky Tofu brine. Besides one can not continue to grow, the other sixteen strains belonged to seven species:Cryptococcus neoformans var. neoformans (ten), Aspergillus clavatus (two), Candida parapsilosis (one), Candida albicans (one), Aspergillus flavus (one), and Penicillium marneffei (one).20 strains of lactic acid bacteria were isolated and identified by 16S rDNA,16 strains belonged to 7 species, Lactobacillus fermentum (5 strains), Lactobacillus plantarum (3 strains), Lactobacillus delbrueckii subsp. Bulgaricus (tree), Lactobacillus paracasei subsp. Paracasei (two), Lactobacillus brevis (one), Pediococcus acidilactici (one) and Lactobacillus crispatus (one). One strain was further identified as Lactobacillus brevis by API 50 CH test strips, and three strains of lactic acid bacteria were not identified by both 16S rDNA and the API 50 CH test strips, which may be the new lactic acid bacteria.The enzyme production capacity of the bacteria and fungi isolated from the Stinky Tofu brine were approved. The lipase production capacity of the Bacillus subtilis and Bacillus amyloliquefaciens are stronger than others. The protease production capacity of Bacillus pumilus and Bacillus licheniformis are stronger than others. The cellulose production capacity of Bacillus licheniformis, Bacillus pumilus and Bacillys sp. B14905 are stronger than others. The lipase production capacity of the Cryptococcus neoformans var. neoformans is the strongest. The cellulose production capacity of Candida albicans and Aspergillus clavatus are stronger than others. For the lactic acid production capacity, Lactobacillus paracasei subsp. Paracasei, Lactobacillus plantarum, Lactobacillus brevis and S1L20 are stronger than others, and the S1L20 is the strongest.