基于26S rDNA D1/D2序列分析酱香型白酒酒醅中酵母菌的群落结构

Composition and distribution of yeasts at different fermentation stages for Maotai-flavor Chinese liquor production

摘要:

摘要:【目的】比较分析不同发酵阶段的酱香型白酒北大仓酒醅中酵母菌的群落结构。【方法】酒醅样本采集自黑龙江省北大仓白酒不同阶段的发酵窖池，采用平板分离技术获得大量酵母菌纯培养物;基于26S rDNAD1/D2区域的碱基序列，准确鉴定酒醅中的酵母菌;根据酵母菌的数量变化、种类组成、相对频率、多样性指数及其相似性系数，研究酱香型北大仓白酒酒醅中酵母菌的群落结构特征。【结果】北大仓白酒酒醅中酵母菌数量在酿造过程中的变化，遵循着“升高-降低-升高-降低”的规律;第1 轮“升高-降低”的过程表现出急剧的“速升速降”特点，而第2 轮“升高-降低”的过程则具有相对来说比较温和的“缓升缓降”特征。酒醅内的酵母菌鉴定为8 属13种，总体多样性指数处于较高的水平，发酵初期酵母菌多样性指数逐渐增加，最高的多样性指数(1. 89)出现在发酵第5 d 的酒醅内;然后又逐渐下降，发酵至第11d时降至最低(0.66);酒醅发酵至 13 d 时开始直至发酵末期，多样性指数呈现出波动性变化。北大仓白酒酒醅中酵母菌的种类组成总体来说比较接近，大多数情况下相似性系数都高于0.5，说明在白酒酿造过程中酵母菌的组成和分布处于一个相对稳定的状态。对于北大仓白酒酒醅内存在的常见酵母菌来说，Issatchenkia orientalis、Pichia kudriavzevii和Saccharomyces cerevisiae可能在酿造过程中发挥更重要的作用。【结论】北大仓等酱香型白酒的酒醅内存在着丰富的酵母菌资源，阐明酒醅内酵母菌的群落结构可以为解析酱香型白酒的发酵机理提供基础数据和理论基础。

Abstract:

Abstract:［Objective］ In order to collect basic data for the analysis of metabolic mechanism，the composition and distribution patterns of yeasts at different fermentation stages for Maotai-flavor Chinese liquor production． ［Methods］By using plate screening techniques，a large number of yeast cultures were obtained from fermenting grains． Based on 26S rDNA D1 /D2 region sequencing，the yeasts were identified． According to quantitative change，species composition，relative frequency，diversity indices and similarity coefficients，the composition and distribution patterns of yeasts were studied． ［Results］The numbers of yeasts in fermenting grains showed a rule of“higher-lower-higher-lower”． A total of 13 species，8 genera of the yeasts were identified． The whole diversity index of the yeasts was comparatively high． That the similarity coefficient in most cases was significantly higher than 0. 5 showed that the species composition and distribution of yeasts were relatively stable． Issatchenkia orientalis，Pichia kudriavzevii and Saccharomyces cerevisiae play a very important role in the process of liquor fermentation． ［Conclusion］There were abundant yeast resources in fermenting grains of maotai-flavor liquor．