浓香型白酒窖泥中可挥发性风味物质与其细菌群落关系解析

Relationship between Volatile Flavor Compounds and Bacterial Communities in Pit Mud of Nongxiang Baijiu

窖泥质量是影响浓香型白酒质量的关键因素之一。为了揭示浓香型白酒窖泥中与挥发性物质积累有关的细菌群落的空间分布,对不同层次窖泥的理化性质进行了研究,采用顶空气相固相微萃取-气相色谱-质谱法(HS-SPME-GC-MS)分析挥发性风味物质,采用变性梯度凝胶电泳法(DGGE)分析窖泥中细菌群落特征,并对二者进行了相关分析。结果表明,主要分布于窖泥下层的Clostridium与己酸、己酸乙酯、丁酸乙酯、己醇有较强的相关性,与丁酸有中等的相关性,对浓香型白酒的香气和风味成分起关键作用,Lactobacillus与乳酸乙酯、正丁醇、2,3-丁二醇呈正相关,Petrimonas sulfuriphila与丙酸高度相关,Syntrophomonas curvata也与正丁醇有关,Proteiniphilum acetatigenes与2-甲基苯酚显著相关,而Hydrogenoanaerobacterium saccharovorans与3-甲基苯酚高度相关,Caloramator mitchellensis与十三酸乙酯呈显著正相关;位于窖泥下层的Lactobacillus acetotolerans、Anaeromassilibacillus senegalensis、Clostridium kluyveri、Clostridium luticellarii、Proteiniphilum saccharofermentans和Petrimonas sulfuriphila与总碳、腐殖质、K^(+)、NH_(4)^(+)-N、Mg^(2+)、PO_(4)^(3-)呈正相关,Clostridium jeddahense、Hydrogenoanaerobacterium saccharovorans、Sedimentibacter hydroxybenzoicus、Petrimonas mucosa,Ardenticatena maritima、Syntrophaceticus schinkii、Clostridium sporosphaeroides、Fermentimonas caenicola和Janthinobacterium lividum呈中等程度的正相关,Thermoclostridium caenicola、Clostridium kluyveri、Clostridium sporosphaeroides、Clostridium luticellarii和Clostridium jeddahense与总碳、腐殖质和镁离子呈显著正相关,Petrimonas sulfuriphila与腐殖质呈正相关,Christensenella massiliensis与NH_(4)^(+)-N、总碳、腐殖质、PO_(4)^(3-)呈负相关。结果可为进一步研究窖泥中挥发性化合物在不同层次中的积累机理提供依据。

The quality of pit mud is one of the critical factors affecting the quality of Nongxiang Baijiu.To reveal the spatial distribution of bacterial communities associated with the accumulation of volatile compounds in pit mud,the physicochemical properties of the pit mud of different layers were compared.HS-SPME-GC-MS was adopted to analyze the volatile flavor compounds,and DGGE was conducted to analyze the bacterial communities.The results showed that,Clostridium in the bottom layer of the pit mud played a key role in the formation of the aroma and flavor of Nongxiang Baijiu,and showed strong correlations with caproic acid,ethyl caproate,ethyl butyrate,and hexanol,and a moderate correlation with butyric acid;Lactobacillus was positively correlated with ethyl lactate,1-butanol,and 2,3-butanediol;Petrimonas sulfuriphila was highly related with propionic acid,Syntrophomonas curvata was related with 1-butanol,Proteiniphilum acetatigenes was significantly correlated with 2-methylphenol,Hydrogenoanaerobacterium saccharovorans was highly related with 3-methylphenol,Caloramator mitchellensis was significantly positively correlated with ethyl tridecanoate.Additionally,Lactobacillus acetotolerans,Anaeromassilibacillus senegalensis,Clostridium kluyveri,Clostridium luticellarii,Proteiniphilum saccharofermentans,and Petrimonas sulfuriphila were positively correlated with total carbon,humus,K^(+)、NH_(4)^(+)-N、Mg^(2+)、PO_(4)^(3-);Clostridium jeddahense,Hydrogenoanaerobacterium saccharovorans,Sedimentibacter hydroxybenzoicus,Petrimonas mucosa,Ardenticatena maritima,Syntrophaceticus schinkii,Clostridium sporosphaeroides,Fermentimonas caenicola,and Janthinobacterium lividum showed moderately positive correlation with those chemical properties;Thermoclostridium caenicola,Clostridium kluyveri,Clostridium sporosphaeroides,Clostridium luticellarii,and Clostridium jeddahense were significantly positively correlated with total carbon,humus,and Mg^(2+);Petrimonas sulfuriphila was positively correlated with humus,while Christensenella massiliensis was negatively correlated with NH_(4)^(+)-N,total carbon,humus,and PO_(4)^(3-).These results have provided a basis for further research on the accumulation mechanism of volatile compounds in different layers of pit mud.