兼香型白酒不同轮次酒醅中酵母菌的种类与数量分析

摘要

采用稀释平板测数和酵母菌分子分类鉴定方法，对白云边酒机械化酿造和传统酿造工艺过程中的第1轮至第7轮入池前堆积料和第3轮至第7轮出池酒醅中酵母菌的数量和种类进行了分析。结果表明，机械化酿造对酵母菌数量的影响具有一定的波动性，不同轮次酒醅中酵母菌的数量与该轮次酒的出酒率和品质呈正相关。从机械化和传统酿造工艺过程中共分离到69株酵母菌，采用酵母菌26S rDNA D1/D2区域序列扩增及同源比对方法，将这些酵母菌株鉴定为7个属7个种，分别为：Pichia. galeiformis、Issatchenkia. orientalis、Saccharomyces. Cere-visiae、Candida. humilis、Torulaspora. delbrueckii、Zygosaccharomyces. bailii、Schizosaccharom. pombe。两种工艺操作过程中，Pichia. galeiformis和Issatchenkia. orientalis均占优势，其中，入池前的堆积醅中均以Issatchenkia. orien-talis和Pichia. galeiformis占优势，而出池酒醅均以Saccharomyces. cerevisiae为优势种，从两种操作工艺中分离的酵母菌种群结构无明显差异。%In this study, in the process of Baiyunbian liquor production (mechanical operation and traditional production respectively), the spe-cies and quantities of yeast strains in stacking grains before pit-entry (from the 1st production cycle to the 7th production cycle) and in ferment-ed grains after pit-exit (from the 3rd production cycle to the 7th production cycle) were analyzed by dilution plate counting coupled with molec-ular classification and identification of yeast strains. The results showed that, the quantities of yeast strains changed up and down in mechanical operations, and the quantities of yeast strains of different turns were positively correlated with the quality and the yield of liquor. 69 yeast strains in total were isolated in the production process and those yeast strains were divided into seven species by homology comparison of 26S rDNA D1/D2 region sequences including Pichia galeiformis, Issatchenkia orientalis, Saccharomyces cerevisiae, Candida humilis, Torulaspora delbrueckii, Zygosaccharomyces bailii and Schizosaccharom pombe. Among them, Pichia galeiformis and Issatchenkia orientalis were domi-nant yeast species in both mechanical operation and traditional production. Issatchenkia orientalis and Pichia galeiformis were the dominant strains in staking grains before pit-entry, while Saccharomyces cerevisiae was the dominant strain in fermented grains after pit-exit. There was no significant difference in yeast community structure for both kinds of operation patterns.