Han Baolin, Gong Hucheng, Ren Xiaohu, Tian Shulin, Wang Yu, Zhang Shufan, Zhang Jiaxu, Luo Jing
College of Bioengineering, Sichuan University of Science & Engineering, Yibin, Sichuan, China.
Chengdu Shuzhiyuan Liquor Industry Co., Ltd, Chengdu, Sichuan, China.
PeerJ. 2024 Feb 29;12:e17000. doi: 10.7717/peerj.17000. eCollection 2024.
Pit mud (PM) is among the key factors determining the quality of Nongxiangxing baijiu, a Chinese liquor. Microorganisms present inside PM are crucial for the unique taste and flavor of this liquor. In this study, headspace solid-phase microextraction was used in combination with gas chromatography and high-throughput sequencing to determine the volatile compounds and microbial community structure of 10- and 40-year PM samples from different spaces. The basic physicochemical properties of the PM were also determined. LEfSe and RDA were used to systematically study the PM in different time spaces. The physicochemical properties and ester content of the 40-year PM were higher than those of the 10-year PM, but the spatial distribution of the two years PM samples exhibited no consistency, except in terms of pH, available phosphorus content, and ester content. In all samples, 29 phyla, 276 families, and 540 genera of bacteria, including four dominant phyla and 20 dominant genera, as well as eight phyla, 24 families, and 34 genera of archaea, including four dominant phyla and seven dominant genera, were identified. The LEfSe analysis yielded 18 differential bacteria and five differential archaea. According to the RDA, the physicochemical properties and ethyl caproate, ethyl octanoate, hexanoic acid, and octanoic acid positively correlated with the differential microorganisms of the 40-year PM, whereas negatively correlated with the differential microorganisms of the 10-year PM. Thus, we inferred that , , and play a dominant and indispensable role in the PM. This study systematically unveils the differences that affect the quality of PM in different time spaces and offers a theoretical basis for improving the declining PM, promoting PM aging, maintaining cellars, and cultivating an artificial PM at a later stage.
窖泥是决定中国白酒浓香型白酒品质的关键因素之一。窖泥中存在的微生物对于这种白酒独特的口感和风味至关重要。在本研究中，采用顶空固相微萃取结合气相色谱和高通量测序技术，测定了来自不同空间的10年和40年窖泥样品中的挥发性化合物和微生物群落结构。还测定了窖泥的基本理化性质。利用线性判别分析效应大小（LEfSe）和冗余分析（RDA）系统地研究了不同时空的窖泥。40年窖泥的理化性质和酯类含量高于10年窖泥，但除pH值、有效磷含量和酯类含量外，这两年窖泥样品的空间分布没有一致性。在所有样品中，共鉴定出29个细菌门、276个细菌科和540个细菌属，包括4个优势门和20个优势属，以及8个古菌门、24个古菌科和34个古菌属，包括4个优势门和7个优势属。LEfSe分析产生了18种差异细菌和5种差异古菌。根据RDA分析，理化性质与己酸乙酯、辛酸乙酯、己酸和辛酸与40年窖泥的差异微生物呈正相关，而与10年窖泥的差异微生物呈负相关。因此，我们推断， 、 和 在窖泥中起主导和不可或缺的作用。本研究系统地揭示了不同时空影响窖泥质量的差异，为改善窖泥质量下降、促进窖泥老化、维护窖池以及后期人工窖泥培养提供了理论依据。
