The Research On Dynamic Change Rule Of Microbes In The High Temperature Stage Of Solid State Fermentation Of Pu-erh Tea

In this study,the whole genomic DNA of the microbes is extracted from the upper,middle and lower layers of the Pu-erh tea with high temperature of more than 45 ?.The 16 S r DNA and ITS fragments are amplified by illumina Miseq technique,and the results of the sequencing of the obtained strains are compared with the database to obtain the specific classification information of the microorganisms in the level of phylum,the class,the order,the family,the genus and the species.In the research,the microbial-specific ecosystems in the various stages of the solid-state fermentation of Pu-erh tea are studied systematically.It will be helpful for us to understand the intrinsic basis of the quality and efficacy of Pu-erh tea.There are two characteristics in this research as follows:(1)The test material is selected from solid state fermentation of the important periods of the upper,middle and lower three full of Pu-erh tea samples.(2)The non-culture of molecular biology technology is applied to obtain a precise fungi and bacterial community accounting data.The main conclusions of this paper are concluded as follows:(1)In most of the Pu-erh tea fermentation period is more than 45 ?high temperature stage,and the middle layer temperature is significantly higher than the upper and lower layers;Raw tea material is dark green color,faint scent,green and yellow soup color;Pu-erh fermented tea is red brown color,significant Chen fragrance,red soup color,sweet taste,reddish brown slightly hard leaves;During Pu-erh tea fermentation,the conversion of quality in the middle is faster than the lower.(2)Through the Shannon curve,Rarefaction curve,Chao1 curve and Species curve,it is found that the sequencing data could reflect the majority of microbial information in the samples;The number of fungal species in the raw material is much higher than the number of fungal species in the other fermentation stages;The diversity of bacteria in 2st middle,5st middle of fermentation group and 5st middle ?of fermentation ? group is significantly higher than that of raw materials and the rest of the samples.(3)Through the analysis of the sequence fragments,it is not found that the fungal fragments did not get classified information after the filtration.The number of fungal species in the raw material is significantly higher than that in the other stages.It is found many bacterial fragments did not get classified information after the filtration,and the richness is much higher than fungi fragments;The number of bacterial species in different fermentation stages has changed dramatically,but there is no significant difference in the number of species in the raw material and the rest of the stages.(4)During high temperature of Pu-erh tea solid-state fermentation,the fungi of Aspergillus,Blastobotrys,Rhizomucor,Thermomyces,Debaryomyces,Candida and Penicillium are dominate,exceeding half of the whole;The bacteria of Pediococcus,Bacillus,Brachybacterium,Erwinia,Trabulsiella,Lactobacillus and Brevibacterium occupy a large amount,but the overall proportion does not exceed 50%.(5)In the process of high temperature solid state fermentation of Pu-erh tea,the fungi group has been showing a concentration trend,and Aspergillus has an absolute advantage in the early stage,and the latter was dominated by Blastobotrys of yeast.The other fungi such as Rhizomucor,owing high proportion occasionally,and there is a big difference between the fungal structure of raw materials and the other stages.The number of Pediococcus species increases significantly in the middle stage of high temperature fermentation,and the number of Bacillus species increases significantly at the late stage of high temperature fermentation.The number of Lactobacillus species changes significantly in the early and late stages of high temperature fermentation,presenting most intense in the lower;The number of species of Erwinia has been a decreasing trend,to the heap when the number has become very little.(6)Through the analysis of PCA principal component analysis,PCo A principal coordinate analysis and UPGMA cluster analysis,it is found that the fermentation of raw materials,fermentation group ?,the middle and lower layers,the proportion of the fungal community in the middle and the ?group is significantly different from that of the other groups.The total composition of the fungal community is relatively unitary,and Ascomycota and Zygomycota are dominated;The common composition of the bacterial community is very variety,and the strain of Proteobacteria,Firmicutes and Cyanobacteria have occupied the dominant position.