Comparison of Bacterial Diversity Between Two Traditional Starters and the Round-Koji-Maker Starter for Traditional Cantonese Chi-Flavor Liquor Brewing.

Jie Wang,Xiang Fang,Yigang Tong,Zhenlin Liao,Hanrong Li,Li Wang,Qingping Zhong,Yingying Yang

doi:10.3389/fmicb.2018.01053

Jie Wang, Xiang Fang + Show 6 more

Open Access

https://doi.org/10.3389/fmicb.2018.01053

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Abstract

Xiaoqu is a traditional fermentation starter that is used for Chinese liquor production. Although microorganisms in the starters are closely associated with the quality and flavor of liquor, knowledge of the microbiota in xiaoqu is still far from complete, let alone the starters produced by new processes. Here, Illumina MiSeq high-throughput sequencing was applied to study bacterial composition in three types of xiaoqu used in Cantonese soybean-flavor (Chi-flavor) liquor, namely two traditional starters (Jiu Bing and Bing Wan) and a Round-Koji-maker starter (San qu) produced by the automatic starter-making disk machine. The results showed bacterial diversity in traditional starters was similar and higher than that in the Round-Koji-maker starter. Lactobacillus and Pediococcus were the dominant genera in all starters, while other different dominant genera also existed in different starters, which were Weissella, Acetobacter, and Gluconobacter for Jiu Bing, Weissella for Bing Wan, and Bacillus, Acetobacter, Acinetobacter and Klebsiella for San qu, respectively. Meanwhile, Cytophagaceae, one particular microbial family, and some pathogens including Klebsiella, Cronobacter, and Enterobacter were also found in San qu, indicating the automatic starter-making disk machine should be ameliorated before applied into industrial production. These results enriched our knowledge on xiaoqu-related microorganisms and might be helpful in industrial Chi-flavor liquor production and the development of fermentation technology.

Highlights

Many different types of liquor, produced by various processes and material in different regions of China, can be distinguished based on the fermentation material, manufacturing techniques, fermentation starters, and product flavors (Zheng and Han, 2016)
Knowledge of the microbiota in xiaoqu is still far from complete, let alone a new type of starter produced by new processes, i.e., the Round-Koji-maker starter produced by using the automatic starter-making disk machine which decreases the influence of operators and reduces labor costs and fermentation time compared with the traditional methods (Cao et al, 2017)
All of the rarefaction curves based on the Operational taxonomic units (OTUs) (Figure 2) tended to reach saturation, indicating that obtained sequenced reads were sufficient to represent the bacterial diversity in different samples

Summary

Introduction

Many different types of liquor (baijiu), produced by various processes and material in different regions of China, can be distinguished based on the fermentation material, manufacturing techniques, fermentation starters, and product flavors (Zheng and Han, 2016). The archaic liquor stems from cereals such as rice and soybean by complex fermentation processes using a natural blended cultural starter called xiaoqu which is one of three different types of the starters called JiuQu used in Chinese liquor (Gou et al, 2015), and the complex fermentation involved numerous steps, such as making starter, distilling, packing and so on This kind of starter works as a saccharifying and fermenting agent for the production of soybean-flavor liquor and contains a variety of microorganisms, enzymes, metabolites and degradation products as well as important flavor compounds, which would contribute to the aroma of the final distillate (Gou et al, 2015). To the best of our knowledge, the bacterial composition of a Round-Koji-maker starter named with San qu was analyzed and compared with that of two traditional fermentation starters named with Bing Wan and Jiu Bing by Illumina MiSeq analysis in this study

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