Study Of Microbial Community Structure Involved In Different Types Of Daqu Based On Gene Clone Libraries Method

Daqu, as the main microbial resource of Chinese liquor brewing, it’s quality can directlyaffect the yield and quality of liquor. In order to further understand the relationship betweenmicrobial community structure of different Daqus and liquor flavor types, five Daqu samples——Fenjiu-Daqus (Qingcha Daqu, Houhuo Daqu, and Hongxin Daqu), Luzhoulaojiao Daqu,Langjiu Daqu were collected as the experimental objects. The microbial community structuresinvolved in different types of Daqu were compared through the gene clone library technologyand PCR-RFLP technology. The main results were indicated as below:(1)The bacterial community composition of different types Daqus:①T he bacteria in thethree types Fen-Daqus were all distribute in Bacilli, Actinobacteridae and Gammaproteobacteria.Lactobacillus and Staphylococcus were the dominant bacteria in Qingcha Daqu (the ratio to totalclones were37.78%and22.22%separately); Lactobacillus, Staphylococcus, Bacillus andWeissella were the dominant bacteria in Houhuo Daqu (the ratio to total clones were35%,16.67%,16.67%,13.33%separately); Lactobacillus, Bacillus and Thermoactinomyces were thedominant bacteria in Hongxin Daqu (the ratio to total clones were26.67%,28.89%,17.78%separately).②The bacteria in Luzhou Daqu were distribute in Bacilli, Actinobacteridae andClostridia. Weissella, Thermoactinomyces and Lactobacillus were the dominant bacteria (theratio to total clones were30.35%,28.57%,19.65%separately).③The bacteria in Langjiu Daquwere distribute in Bacilli. Virgibacillus and Thermoactinomyces were the dominant bacteria (theratio to total clones were44.83%,43.1%separately).(2)The fungal community composition of different types Daqu:①The fungi in the threetypes Fen-Daqus were all distribute in, Saccharomycetales and Mucorales. Pichia and Rhizopuswere the dominant fungi in Qingcha Daqu (the ratio to total clones were66.7%and30%separately); Pichia was the sominant fungi in Houhuo Daqu (the ratio to total clones was80.24%); Rhizopus and Lichtheimia were the dominant fungi in Hongxin Daqu (the ratio to totalclones were38.89%and33.3%separately).②The fungi in Luzhou Daqu were distribute in Eurotiales, Mucorales and Saccharomycetales. Aspergillus and Saccharomycopsis were thedominant fungi in Luzhou Daqu (the ratio to total clones were36.9%and25%separately);③T he fungal community in Langjiu Daqu were similar as that of Luzhou Daqu, were distributein Eurotiales, Mucorales and Saccharomycetales. Aspergillus and Thermomyces were thedominant fungi in Langjiu Daqu (the ratio to total clones were40.26%and38.96%separately).(3)The differences of bacterial community structure between different types Daqu:①Bacterial diversity ofthe5types Daqus from high to low were as below: Houhuo Daqu＞Qingcha Daqu＞Luzhou Daqu＞Hongxin Daqu＞Langjiu Daqu. The fungal diversity of the5types Daqus from high to low were as below: Luzhou Daqu＞Hongxin Daqu＞Langjiu Daqu＞Qingcha Daqu＞Houhuo Daqu.②The microbial community structure were obvious differentamong the5types Daqus. And with the rise of starter-making temperature, high temperatureresistant bacteria (Bacillus and Thermoactinomyces), Thermophilic or heat risistant mold alsogradually increased.③Compared with the traditional cultivation method, this experiment foundsome new microorganism, such as Virgibacillus, Leuconostoc, Staphylococcus,Thermoactinomyces, Streptomyces, Saccharopolyspora, Aspergillus penicillioides, Xeromycesbisporus, Thermomucor indicae-seudaticae, Trichomonascus ciferrii.