Bacteria Diversity And Dynamic Evolution In The Fermentation Process Of Pi Xian Broad Bean Paste

So many research studied on the microorganisms existed in the fermentation process of broad bean paste nowadays.They mainly amid at some special periods,some kinds of functional microorganisms and some research methods.While,a comprehensive study on bacterial diversity and dynamic evolution in the fermentation process of broad bean paste was not appeared.Therefore,the aim of this project was to solve that problem by using the pure culture method and high-throughput sequencing technologies.On the basis of high-throughput sequencing data,OTU clustering analysis,Alpha diversity index analysis,beta diversity analysis and different classification of the phylum and genus level were used to detection the fermentation bacteria in different stages of broad bean paste.The results confirned that the sample of PJ3 Y contained the most abundant bacteria species.The number of bacteria remain stable in the process of petals fermentation,but the species were not the same.Bacterial species showed a trend of increased after decreased first in mixed samples.Dynamic succession analysis of bacteria showed that Pantoea,Enterobacter and Pseudomonas were the dominant bacteria in chill fermentation.Staphylococcus,Corynebacterium and Brevibacterium were the mainly bacteria in the early stage of broad bean fermentation.It is a trend of decline in Brevibacterium content along with the fermentation and a gradually increasing in Bacillus genus that lead it to be preponderance in fermentation metaphase.At the end of fermentation,Lactobacillus and Pediococcus became active which grew quickly.In mixed fermentation period,the dominant bacteria were Staphylococcus,Weissella and Tetragenococcus.As mixed fermentation continues,the content of Staphylococcus and Tetragenococcus showed a tendency of increase,meanwhile slowly declined happened in Weissella.It's worth noting that Staphylococcus is the main community in the whole fermentation process.Six kinds of improved culture medium adding different salt concentration used for separation of bacteria in pure culture.The result indicated that early fermentation had the most abundant bacteria species.Seven different species were detected in this experiment,such as Bacillus,Oceanobacillus,Halomonas,Lactobacillus,Virgibacillus,Enterobacter and Gracilibacillus.Along with the fermentation,primitive bacteria species decreased gradually and no new species detected in whole period.Only Bacillus,Oceanobacillus and Halomonas exists in the various periods of fermentation.In general,the species were very rich in broad bean paste fermentation process.with a large number of increase and decrease in original species and occurrence of secondary species,uncultured bacterium gradually increased.It is the mainly component at the end of fermentation.