The Dynamics Analysis of Fungal Community Diversity During the Fermentation Process of Chinese Traditional Soybean Paste

Purpose The aim of this work was to monitor the microflora and the changing principle of the fungi family at the natural fermented soybean paste different fermentation stage. Methods It obtained the V4 and V5 regions of the 18S rDNA by extracting the fungal genomic DNA from the natural fermented soybean paste. DGGE fingerprint of fungal 18S rDNA V4 (partial), V5 sections during the different soybean paste fermentation periods of 17 samples were line analyzed. The abundance, the absorbance and the degree of dominance and diversity indexes of fungal community were determined by the denaturing gradient gel electrophoresis (DGGE). Results The V4, V5 regions of 18S rDNA of the complex microbial community in the fermentation of traditional soybean paste were around 762 bp and 422 bp, and there were 9 kinds of microorganisms discovered, which were Penicillium expansum , Aspergillus oryzae , Mucor , P. commune , Absidia corymbifera , M. racemosus , Actinomucor elegans , Aspergillus, and an unculturable fungi. The DGGE ecological analysis showed that the unculturable fungi and A. oryzae were dominant microorganisms all the time, and the highest diversion index of 2.87 was reached at 56 days of fermentation. Conclusion This study laid a foundation for researching suitable soybean paste artificial inoculation and also provided a good help for the fermentation process of soybean paste. Graphic Abstract