Brewing Microbes Analyzing And Fermentation Study Of Issatchenkia Orientalis In Baiyunbian Liquor

In this study,7 yeast strains were isolated from fermenting packing materials and fermented grains of Baiyunbian Liquor,and were named as Z1,Z2,Z3,Z4,FJ5,BYB-2 and BYB-3 separately.Then five distinct strains were isolated from the wheat , high temperature daqu, and medium temperature starter supplied by Baiyunbian Liquor,using Rose Bengal Medium,Beef extract-peptone medium and Koji extract medium and also were named as WB-1,WB-2,WP-1,ZP-1 and ZP-2.The 16 S rDNA,18S rDNA and 26 S rDNA sequences of the strains were obtained by PCR amplification and were subjected to homology search and identified.The 4 following yeast strains Z1,Z2,Z3 and FJ5 were all belonged to Issatchenkia orientalis.The 3 rest yeast strains Z4,BYB-2 and BYB-3 were belonged to Candida tropicalis,Saccharomyces cerevisiae and Pichia galeiformis or Pichia manshurica respectively.The strains WB-1 and WB-2 were shown to be 99% and 100% phylogenetically similar to the type strains of Bacillus amyloliquefaciens and Bacillus subtils, respectively . Strain ZB-1 were showed to be 88% phylogenetically similar to the type strains Methylobacillus sp. or Methylophilus sp.. The strains WP-1,ZP-1 and ZP-2 were shown to be 99%,100% and 88% phylogenetically similar to the type strains of Paecilomyces spectabilis,Absidia corymbifera and Rhizomucor pusillus, respectively.The results showed that,the main type of yeasts of fermenting packing materials and fermented grains is Issatchenkia orientalis;the main types of fungi and bacteria in the material wheat are basically similar with high temperature daqu,while the medium temperature starter are quite different from it.The advantage fungi in Baiyunbian high temperature daqu is Paecilomyces spectabilis,and no high temperature fungi was found.According to this study,Issatchenkia orientalis Z1 is proved to be the best strain during the Alcohol tolerance,heat-resisting ability and fermentation study.It has a good ability at acetate ethyl producing,and in mixed fermentations it also keeps a high acetate ethyl production,while having no negative influence on ethanol producing .