Characterization of Interphase Microbial Community in Luzhou-Flavored Liquor Manufacturing Pits of Various Ages by Polyphasic Detection Methods

Abstract

It is vital to understand the changing characteristics of interphase microbial communities and interspecies synergism during the fermentation of Chinese liquors. In this study, microbial communities in the three indispensable phases (pit mud, zaopei, and huangshui) of Luzhou-flavored liquor manufacturing pits and their shifts during cellars use were first investigated by polyphasic culture-independent approaches. The archaeal and eubacterial communities in the three phases were quantitatively assessed by combined phospholipid ether lipids/phospholipid fatty acid analysis and fluorescence in situ hybridization. In addition, qualitative information regarding the microbial community was analyzed by PCR-denaturing gradient gel electrophoresis. Results suggested that the interphase microbial community profiles were quite different, and the proportions of specific microbial groups evolved gradually. Anaerobic bacteria and gram-positive bacteria were dominant and their numbers were higher in pit mud (10 cells/g) than in huangshui (10 cells/ml) and zaopei (10cells/g). Hydrogenotrophic methanogenic archaea were the dominant archaea, and their proportions were virtually unchanged in pit mud (around 65%), whereas they first increased and then decreased in zaopei (59%-82%-47%) and increased with pit age in huangshui (82%-92%). Interactions between microbial communities, especially between eubacteria and methanogens, played a key role in the formation of favorable niches for liquor fermentation. Furthermore, daqu (an essential saccharifying and fermentative agent) and metabolic regulation parameters greatly affected the microbial community.

Characterisation and comparison of the microflora of traditional and pure culturexiaoquduring thebaijiuliquor brewing process

“…Bacillus can also produce aromatic and phenolic compounds, which improve the sensory appeal of the liquor . Lactobacillius and Lactococcus are common bacteria in jiuqu , and produce lactic acid which contributes to the formation of ethyl lactate, which is a vital flavour compound in light flavour type liquor . When considering low abundance bacteria, Gluconobacter oxydans , Oceanbacillus profundus , Weissella paramesenteroides , Methylobacterium aquaticum , Bacillus oleronius and Bacillus ginsengihumi occurred at different times in the liquor brewing process and further investigation is required to understand their contribution to the liquor brewing process.…”

Diversity, Function, and Application of Clostridium in Chinese Strong Flavor Baijiu Ecosystem: A Review

“…For example, C. ljungdahlii was able to cometabolize CO 2 and H 2 to acetate and ethanol, which can be used for the production of butyrate and caproic acid by C. kluyveri (Richter, Molitor, Diender, Sousa, & Angenent, ). Another synergistic interaction is the interspecies hydrogen transfer (Thauer, Kaster, Seedorf, Buckel, & Hedderich, ), as the existence of many hydrogen producing Clostridium bacteria and methanogenic archaea in the SFB ecosystem (Ding et al., , , ; Hu et al., ; Li et al., ; Luo et al., ; Tao et al., ; Wu, Ding, Huang, & Zhou, ; Zheng et al., ). Interspecies hydrogen transfer between Clostridium and methanogenic archaea is beneficial to maintain the stability of the community and niches and also for the forming of many valuable metabolites (Hu et al., ).…”

“…Other studies revealed that C. kluyveri was in highly co‐occurrence with the Methanobacteria class (Hu et al., ) . Methanobacterium is one of the predominant genera found in different pit muds (Ding et al., , , ; Hu et al., ; Li et al., ; Luo et al., ; Tao et al., ; Wu et al., ; Zheng et al., ) and Zaopei (Li et al., ; Sun et al., ). In addition, C. tyrobutyricum isolated from pit mud did not produce caproic acid in monoculture, but the yield of caproic acid reached 1.8 g/L when it was cocultured with Bacillus (unpublished data).…”

Design, Optimization and Verification of 16S rRNA Oligonucleotide Probes of Fluorescence in-situ Hybridization for Targeting Clostridium spp. and Clostridium kluyveri

“…These samples were pretreated prior to examination according to the method described by Li et al [22].…”

“…It has been used to characterize the archaeal community in complex environments [18,19]. In our previous researches, the microbial communities in PM were characterized by FISH using various order-specific oligonucleotide probes [20][21][22][23][24]. The composition of four orders methanogenicarchaeal (methanosarcinales, methanobacteriales, methanomicrobiales and methanococcales) in various aged PM were also estimated quantitatively [25].…”