浓香型白酒发酵过程中窖内古菌群落分布特征

Distribution of archaeal community in the mud pit during strong-flavor baijiu fermentation

摘要:

泥窖池多菌种固态发酵是浓香型白酒的典型特点，其中古菌是重要的酿造功能菌，但目前对发酵过程古菌的群落分布及多样性尚缺乏研究。采用高通量测序技术，分析了浓香型白酒发酵过程酒醅与窖泥中古菌的生物量、群落组成与演替规律，并通过共现性网络分析了古菌与细菌的潜在互作关系。结果表明，窖泥中古菌平均生物量约是酒醅的200倍，两者之间古菌群落的结构差异不显著 (r=0.017，P=0.074)，但演替规律存在显著相关性 (r=0.30，P=0.03)。甲烷杆菌属 Methanobacterium 是酒醅与窖泥中丰度占比最高的古菌，其他优势群类依次为甲烷八叠球菌属 Methanosarcina、甲烷粒菌属 Methanocorpusculum、甲烷囊菌属 Methanoculleus 和甲烷短杆菌属 Methanobrevibacter。共现性网络分析显示甲烷杆菌属在酒醅与窖泥中与多数细菌为正相关，特别是与窖泥中主要细菌氢孢菌属Hydrogenispora 和产己酸菌属 Caproiciproducens。研究结果揭示了浓香型白酒窖池中古菌群落的时空分布特点及潜在功能。

关键词:浓香型白酒，酒醅，窖泥，发酵过程，共现性网络

Abstract:

Multi-species solid-state fermentation in a mud pit is one of the typical features of strong-flavor baijiu, in which archaea plays important roles, however, the archaeal community distribution and diversity during fermentation are still lack of research. The biomass, composition and succession of archaea communities in fermented grains and pit mud were analyzed by high throughput sequencing. The potential interaction between archaea and bacteria was analyzed by co-occurrence network. Results demonstrate that the average biomass of archaea in pit mud was about 200 times higher than that of fermented grains. There was no significant difference in archaeal community structure between fermented grains and pit mud (r=0.017, P=0.074), but succession patterns between them showed significant correlation (r=0.30, P=0.03). Methanobacterium was the most abundant archaea in fermented grains and pit mud, and other dominant groups included Methanosarcina, Methanocorpusculum, Methanoculleus, and Methanobrevibacter. The co-occurrence network analysis showed that Methanobacterium was positively correlated with most bacteria in fermented grains and pit mud, especially with Hydrogenispora and Caproiciproducens, the dominant bacteria in pit mud. Our results revealed the temporal and spatial distribution characteristics and potential functions of the archaeal community in the mud pit of strong-flavor baijiu.

Key words:strong-flavor baijiu, jiupei, pit mud, fermentation process, co-occurrence network