浓香型酒醅中梭菌群落演替及其与理化性质的相关性分析

Dynamic clostridial community succession and its correlation with physicochemical factors in Jiupei for strong flavor Baijiu production

采用高通量测序和实时荧光定量PCR技术解析了浓香型酒醅发酵过程中梭菌纲细菌群落多样性、组成及演替规律,并对酒醅梭菌群落及其理化因子进行了冗余分析(redundancy analysis,RDA)和Pearson相关性分析。结果表明,梭菌的多样性和相对丰度在发酵第7天最低,45 d达到最高。供试样品中梭菌群落由1个目、13个科和39个属组成,其中Caproiciproducens(己酸菌属)和Clostridium_sensu_stricto_1(狭义梭菌属1)是主要的菌属,均呈现先减少后增加再减少的趋势。RDA结果表明,理化因子的贡献率依次为温度(45.5%)>含水量(17.8%)>铵态氮(11.0%)>还原糖(10.3%)>乙醇(8.0%)>pH(5.2%)>总酯(1.5%)>总酸(0.6%),温度与梭菌群落结构呈极显著关系(P<0.01)。Caproiciproducens、Fonticella、Anaerofilu与总酸呈显著正相关(0.01<P<0.05),与含水量呈极显著正相关(0.001<P<0.01)。此外,含水量与Butyrivibrio_2(丁酸弧菌属)具有更强的相关性(0.0001<P<0.001),温度与相对丰度前10种梭菌均呈负相关。该研究丰富了浓香型白酒发酵过程中对梭菌群落及其影响因素的认识,为发酵过程中梭菌群落的调控提供了理论支撑。

Based on the combination of high-throughput sequencing and real-time PCR technologies,the diversity,composition,and succession of the clostridial community in Jiupei of Chinese strong flavor Baijiu were analyzed.Moreover,the clostridial community and its physicochemical factors were analyzed by redundancy analysis(RDA)and Pearson correlation analysis,respectively.The results showed that both the diversity and relative abundance of clostridial were at the lowest level on the 7 th day for the fermentation but at the highest level on the 45 th day.The clostridial community was composed of 1 order,13 families,and 39 genera in the tested Jiupei samples.Among them,the Caproiciproducens and Clostridium_sensu_stricto_1,with relative abundance decreased first,then increased and then decreased during the fermentation process,were the dominant clostridial genera.RDA results showed that the contribution rates of physicochemical factors were temperature(45.5%)>water content(17.8%)>ammonium nitrogen(11.0%)>reducing sugar(10.3%)>ethanol(8.0%)>pH(5.2%)>total esters(1.5)>total acids(0.6%),respectively.There was a very significant relationship between temperature and clostridial community structure(P<0.01).Capriciproducens,Fonticella and Anaerofilu were significantly positively correlated with total acid composition(0.01<P<0.05)and extremely significantly positively correlated with water content(0.001<P<0.01).In addition,there was a stronger correlation(0.0001<P<0.001)between water content and Butyrivibrio_2 observed,and the temperature was negatively correlated with the relative abundances of the top 10 clostridial genera,respectively.This study enriched the understanding of the clostridial community and its influencing factors in Jiupei samples,which could provide the theoretical support for regulating the clostridial community during the fermentation process for the Chinese strong flavor Baijiu production.