High-throughput Sequencing Revealed Fungal Community Structures In Traditional Shaoxing Huangjiu Brewing

Huangjiu is a traditional alcoholic fermented beverage in China with mellow taste and unique flavor.Because the traditional microbial culture methods have some limitations and can not fully reflect the microbial diversity of Huangjiu brewing,high-throughput sequencing technique was used to analyze the community structure of fungi in traditional Shaoxing Huangjiu brewing.The fungal diversity,community composition structure and correlation analysis of Maiqu,Linfanjiumu,fermentation mash of Huangjiu in Shaoxing five Huangjiu enterprises were studied.To provide a certain theoretical basis for understanding the microbial diversity of Huangjiu brewing and improving the quality of Huangjiu,the main conclusions of this paper are as follows: The main results are as follows:(1)This paper analyzed the diversity of community structure of brewing fungi in saccharification starter of Shaoxing Hunagjiu,then explored the relevant fungi community from four local enterprises.It was found that the fungal diversity of Huangjiu saccharifying agent was higher than that of Huangjiu starter in J,K,Z and G enterprises.The brewing fungi diversity of saccharifying starter in J enterprise was the highest,while K enterprise was the most abundant.The community structure of brewing fungi in Huangjiu saccharifying starter was analyzed at the phylum level,and it was found that Ascomycota were all dominant phylum.At the genus level,the dominant genera of saccharifying agents from different sources were different.Saccharomyces and Saccharomycopsis were the dominant fungi of Huangjiu fermentation agents of the four major enterprises,indicating that saccharification fermentation agents of different enterprises have similar community structure composition of brewing fungi,with certain differences in their relative abundance and composition ratio.It further analyzed the species difference between Linfanjiumu and Maiqu,indicating that there were differences in the fungal species composition of saccharification starter from different enterprises.Compared with Linfanjiumu and Maiqu,there were more distinct fungal species in Maiqu.According to the analysis of the correlation network diagram,it can be found that there were 6 positively related Hubs and 3negatively related Hubs for brewing fungi in the saccharification starter of Huangjiu,also 6positively related Hubs in Maiqu,which was stronger than negative correlation and played an important role in the stability of the ecosystem of Huangjiu brewing fungi.(2)In order to reveal the formation mechanism of fungal community and diversity during the production of Shaoxing Huangjiu,high-throughput sequencing platform was used to study the fungal resources in the samples of Linfanjiumu,Maiqu and fermentation mash from W enterprise.A total of 136000,215283,166150 and 143624 sequences were obtained from the samples of Linfanjiumu,Maiqu,initial mash and mature mash,respectively.After clustering,32,133,107 and 84 OTU(operational taxonomic units)were obtained respectively.The diversity and richness of fungi were in order of Maiqu > initial mash > mature mash > Linfanjiumu.At the level of phylum,Ascomycota in all samples were dominant;at the level of genus,Saccharomyces showed an obvious distribution advantage in Linfanjiumu,Aspergillus was the dominant fungi in Maiqu,and Saccharomyces and Aspergillus were the dominant fungi in the initial and mature mash.With the extension of the fermentation time of Huangjiu,the proportion of Saccharomyces in the mash gradually increased,while other fungal groups including Aspergillus showed a decreasing trend.According to the results of PCo A analysis and similarity cluster analysis of fungal community,the structure of fungi in Linfanjiumu,initial mash and mature mash was much more similar,while the fungal resources in Maiqu were quite different from other samples.The analysis of fungal community characteristics in the initial mash showed that the Linfanjiumu and Maiqu had an important impact on the formation of fungal diversity in Shaoxing Huangjiu.The dominant species of saccharification and fermentation starter(Linfanjiumu and Maiqu)played a leading role in the community construction of fermentation fungi.