Analysis Of Mrcrobial Community Strucyure And Diversity In Underground Pit Mud

In this paper,the underground pit is used to build the fermentation cellar room under the ground,the temperature and humidity of the undergroud pit are more constant,which can be produced continuously in hot summer.The fermentation process of Luzhou-flavor liquor is used pit mud for media,the pit mud quality determine the liquor's quality and output.In this paper,seleted ground and underground pit mud for experimental subject.The physical and chemical indexses of pit mud in these two pits and the change trend of microbial community structure in spring,summer and winter were studied.The specific conclusions were as follows:The change trend of physical and chemical indexes of the two kinds of pit mud in different seasons:?1?The difference between the two kinds of pit mud was not obvious in terms of color,smell and sensory index.The contents of water,ammonium nitrogen,total nitrogen,pH vaule,calcium and iron of the pit mud in underground cellar room were exceed pit mud in underground cellar room in deffirent seasons.But the contents of humic acid,available phosphorus were opposite.The contents of humic acid,pH value,available phosphorus and iron in the two kinds of pit mud changed little with the seasons.The water,ammonium nitrogen,calcium and total nitrogen of the pit mud in underground pit changed little with the seasons,while the contents of the three physical and chemical factors of the pit mud in ground pit changed more with the seasons.?2?Differences of bacteria between the two kinds of pit mud in different season: The microbial community structures of the two kinds of pit mud were analyzed by high throughput sequencing.On average,314 OTUs classifications were obtained form the mud samples of underground pit,and 351 OTUs classifications were obtained form the mud samples of ground pit.Six different categories were detected in both pits,and the dominant bacteria were firmicutes and bacteroidetes.In class classification level,there are obvious difference between the two kinds of pit mud,the dominant bacterial community in ground are Petrimonas ? Hydrogenispora ?Christensenellaceae_R-7_group and Proteiniphilum,and the dominant bacterial community in underground were Caproiciproducena-Prevotella₇,Caldicoprobacter and Petrimonas.Caldicoprobacter and Clostridium were functional bacteria in Luzhou-flavor liquor produce.the both two functional bacteria's content in pit mud in ground pit exceed pit mud in underground pit,and the change trend in diffirent seasons were more steady.?3?Differences of archaea between the two kinds of pit mud in different seasons: Nine OTU classifications were obtained in each mud of ground pit,and seven OTU classifications were obtained in each mud of underground pit.There was no significant difference in the richness and diversity of the two kinds of archaea of pit mud.There was only Euryarchaeota of the two kinds of pit mud,which was archaea,two classes,three families and four genera were detected.In the level of genus,Methanobacteria account for the largest proportion in underground pit mud.The dominant class of ground pit mud were methanobacteria and methanobacteria.?4?There are correlations btween physicochemical factors and microbial community structure.The ammonium nitrogen and total nitrogen content in pit mud in underground pit exceed pit mud in ground pit,and the thick wall bacteria and actinomycetes' s content were higher.