Analysis of Microbial Community Structure and Volatile Compounds in the Pit Mud Used for Manufacturing Taorong-type Baijiu Based on High-Throughput Sequencing

Abstract

In this study, the pit mud used in manufacturing Taorong-type Baijiu was collected from the upper, middle, lower and bottom layers of pits in Henan Yangshao Liquor Co., LTD. Besides, high-throughput sequencing (HTS) technology was adopted to analyze the microbial community structure of the pit mud. In addition, the volatile compounds in the pit mud were subjected to preliminarily qualitative analysis through headspace-solid phase microextraction (HS-SPME) and gas chromatography-mass spectrometry (GC-MS). The results of HTS demonstrated that there were 5, 3, 5 and 5 dominant bacterial phyla (including 11, 11, 9 and 8 dominant bacterial genera) and 3, 3, 3 and 3 dominant fungal phyla (including 4, 7, 7 and 5 dominant fungal genera) in the pit mud from F-S (upper), G-Z (middle), H-X (lower) and I-D (bottom), respectively. The qualitative analysis results of volatile compounds demonstrated that a total of 78 kinds of volatile compounds were detected in the pit mud, including 46, 45, 39 and 49 kinds in the pit mud from F-S, G-Z, H-X and I-D, respectively. Ester and acid were the two main components in the pit mud. Meanwhile, the correlation between microorganisms and main volatile compounds in the pit mud was analyzed. Moreover, Lentimicrobium, Syner-01 and Blvii28_wastewater-sludge group were found for the first time in the pit mud used for manufacturing Taorong-type Baijiu. The findings of this study could provide a theoretical foundation for improving the quality of pit mud and the flavor of Taorong-type Baijiu.