Resource And Diversity Of Fungi From Fermented Grains In Maotai-flavor Liquor

The fermentation pit is a kind of solid bioreactors for Chinese liquor.In the paper,characteristics of microbial community structure in the fermentation pit have significanteffects on the quality and style of the product. Diversity and function of the fungi in thefermentation pit are explained and research directions in future are put forward in the paper.One pit in BeiDacang distillery are chosen as the object analyzed,and research theresource of fungi by morphology characteristics.In one period,We collect the samplescontinuously,and then adopt the method of CFU to analyze the change of the fungi quantity.Atotal of328isolates of fungi are recovered,they are identified to13genera,23species,including3to Ascomycetes,1to Zygomycete and19to Mitosporic fungi.We researche the community composition and activity analysis of functional enzymes ofmold from fermented grains.The results show that the changing rule and tendency of numbersof mold are basically consistent respectively in upper, middle and lower fermented grains.Thenumbers of mold fall sharply after fermentation and then momently increased in middle stage.After that mold numbers again reduce in later period until the end. Of these the occurrencefrequency of Alternaria, Aspergillus, Cladosprium, Eurotium, Geotrichum, Monascus,Neurospora, Paecilomyces, Penicillium, Stachybotrys, Mucor in some fermentation stagereache above10%, but Geniculosporium and Scopulariopsis appeare with lower frequency.The total diversity index (1.47-2.57) of mold from fermented grains is high and the biggest isin early sealed pits. According to similarity coefficient, the community composition aresimilar in early fermentation period (1-3d), but community composition apparently chang inthe fifth day. The kinds of functional enzymes produce by Aspergillus and Penicillium areabundant and all functional enzymes have an important impact on the use of raw materialsand the formation of flavor substances.Community structure and the variety of yeasts in Bei Dacang fermentation pit areidentified according to the analysis of the26s rDNA.It is at a high level of the yeasts`totaldiversity index.,in early sealed pits,it increases gradually until the highest(1.89) apeared at thefifeh day.Then it drops step by step,and falls to the lowest point(0.66) at the eleventhday.From the thirteenth day to the evening fermentation period,the diversity index is changdewavely.The variety of the yeasts in the pits is similar totaly, similarity coefficient is greaterthan0.5in most situations. Issatchenkia orientalis,Pichia kudriavzevii and Saccharomyces cerevisiae are the dominant microbe,they bring into a inportant affect possibillity at thefermentation period of Beidacang.