Bacterial Communities and Prediction of Microbial Metabolic Pathway in Rice Wine Koji From Different Regions in China

Abstract

Rice wine koji, a traditional homemade starter culture in China, is nutritious and delicious. The final quality of rice wine koji is closely related to the structure of its microbial community. However, the diversity of natural microorganisms in rice wine koji from different regions has not been evaluated. In this study, the microbial population of 92 naturally fermented rice koji samples collected from Hubei, Guangxi, and Sichuan was systematically analyzed by high-throughput sequencing. From all the rice wine koji samples, 22 phyla and 479 bacterial genera were identified. Weissella, Pediococcus, Lactobacillus, Enterobacter, Lactococcus, Pantoea, Bacillus, Staphylococcus, and Leuconostoc were the dominant genera in rice wine koji. The bacterial community structure of rice wine koji samples from different regions was significantly different (p < 0.05). The bacterial community composition of the samples from Hubei and Guangxi was similar, but significantly different from that of SC samples (p < 0.05). These differences may be caused by variations in geography, environment, or manufacturing. In addition, the results of microbial phenotype prediction by BugBase and bacterial functional potential prediction by PICRUSt showed that eight of the nine predicted phenotypic functions of rice wine koji samples from different regions were significantly different (p < 0.05) and that vigorous bacterial metabolism occurred in rice wine koji samples.

Microbial Communities and Correlation between Microbiota and Volatile Compounds in Fermentation Starters of Chinese Sweet Rice Wine from Different Regions

“…Moreover, LAB play critical roles in the production of proteins and metabolites such as esterases, lipases, and alcohol acetyl transferases that reportedly contribute to the formation of flavor-related components of wine [10]. Among the prevalent LAB genera, Weissella showed the highest abundance, especially in YC1, YC2, and XG starters, consistent with previous studies that found Weissella is the dominant genus in rice wine koji [6], although other studies have identified Bacillus as a dominant genus among starter microbiota [1]. In addition, Weissella is a representative genus in CSRW starters of Hubei province, which was consistent with previous studies that showed Weissella was a representative genus in Wheat Qu of Hubei province [13].…”

“…Hierarchical clustering of the CSRW starter samples based on the abundance of bacterial and fungal genera showed similar results to the PCoA plot (Figure 4C,D). Taken together, these results showed that the microbial communities of CSRW starters from different regions exhibited both variability and similarities, which was consistent with findings in previous analyses of CSRW starters [1,6]. The close position among samples indicated similarities in the composition of principal genera, while more distant samples in the PCoA plot reflected differences in these principal genera.…”

“…The Jiuqu for CSRW is made with rice flour and Chinese herbal medicine under open conditions, which is different from the wheat Qu (fermented by Aspergillus) used for Chinese yellow rice wine [4,5]. Regional variations in the wild native microbes and environmental conditions of Jiuqu production can potentially influence the microbial community composition and quality of Jiuqu, especially in non-sterile fermentation processes [6]. The influence of environment in different regions can also lead to differences in CSRW starters, which may impart distinct sensory profiles, flavors, and other characteristics to the CSRW [7].…”

Research Progress on Flavor and Quality of Chinese Rice Wine in the Brewing Process

“…BR14 is considered a probiotic Saccharomyces cerevisiae that can significantly increase alcohol content and total acidity. Additionally, cofermentation of BR14 can significantly reduce the urea content of EC formation . Yuan et al.…”

“…Additionally, cofermentation of BR14 can significantly reduce the urea content of EC formation. 56 Yuan et al. isolated a yeast strain (YB-12), for which the gene sequence was highly similar to that of Meyerozyma , and found that YB-12 could significantly reduce the content of fusel alcohols in CRW.…”