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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. [ABSTRACT FROM AUTHOR]

In this study, the physicochemical characteristics and bacterial community structure of Yunmen medium-high temperature Daqu were investigated. At the same time, the bacterial community structures of medium-high temperature Daqu from Yunmen and Yingtan were compared and analyzed. The results showed that Yunmen medium-high temperature Daqu was rich in culturable bacteria, and the highest number of Bacillus amyloliquefaciens (33.33 %). The moisture content (8.28 % ± 0.62 %) of Yunmen medium-high temperature Daqu was low, but its acidity (9.26 ± 2.08 mmoL/10 g) and starch content (66.20 % ± 2.80 %) were high, which were related to the relative abundance of Latilactobacillus , Companilactobacillus , Weissella , and Bacillus. Compared with Yingtan medium-high temperature Daqu, the significantly lower Shannon index and Simpson index (P < 0.05); the weaker correlation between bacterial networks, especially positive correlation; and the lower relative abundance of core bacterial communities of Yunmen medium-high temperature Daqu. Overall, this study evaluated the quality of Yunmen medium-high temperature Daqu and revealed the bacterial community structure of medium-high temperature Daqu from two different regions. The results could guide the future exploration of fermentation mechanisms in medium-high temperature Daqu. [Display omitted] • Excavating the lactic acid bacteria and Bacillus from Yunmen medium-high temperature Daqu. • Elucidating the relationship between dominant bacterial genera and physicochemical characteristics of Yunmen medium-high temperature Daqu. • Exploring the potential functional bacteria of medium-high temperature Daqu in different regions. • Revealing the core bacterial communities of medium-high temperature Daqu. [ABSTRACT FROM AUTHOR]

The varying degrees of browning due to the Maillard reaction result in distinct characteristics across different parts within the cross-section of Houhuo low-temperature Daqu (LTD). However, the microbial community structure of the peel and core of Daqu is still poorly understood. In this study, using a combination of high-throughput sequencing and pure culture techniques, the microbial communities present in the peel and core of Houhuo LTD were compared and analyzed. Bacillus (58.84%) and Saccharomycopsis (87.61%) were the main bacterial and fungal genera present in Houhuo LTD. The abundance and diversity of fungi were significantly lower in peel samples (P < 0.01). At the bacterial genus level, Sphingobium , Staphylococcus , and Streptomyces were significantly enriched in peel samples, while Saccharopolyspora was significantly enriched in core samples (P < 0.05). At the fungal genus level, Saccharomycopsis and Clavispora were significantly enriched in peel samples, while Monascus and Aspergillus were significantly enriched in core samples (P < 0.05). Differences in the layers of LTD block had a greater effect on the correlation between bacterial genera, and the microbial networks in the peel samples were more compact. Some microbial groups were common to the two groups, including the main bacterial genera Bacillus , Saccharopolyspora , Streptomyces , and Staphylococcus and the main fungal genera Saccharomycopsis and Monascus. Pure culture techniques revealed that B. paralicheniformis , Pediococcus pentosaceus , and S. fibuligera were the most abundant strains of Bacillus , lactic acid bacteria, and yeast in all samples, respectively. The findings could support the optimization of the Daqu-making processes and the screening of microbial strains for brewing. • There are differences in the microbial community structure between the peel and core of Houhuo Low-temperature Daqu (LTD). • Yeast was more abundant in the peel of Houhuo LTD, and mold was more abundant in the core of Daqu. • Bacillus and Saccharomycopsis were the main microbial communities of Houhuo LTD. [ABSTRACT FROM AUTHOR]

Rice wine, a traditional fermented alcoholic beverage in China, is produced with grains such as rice, which are fermented with saccharifying starter-koji. Its flavor quality is closely associated to the starter culture-koji, which is made by mixing botanical materials with high-class glutinous rice in certain ecological context. However, there are few reports on the microbial community structure of rice wine koji. In this paper, bacterial community structures of rice wine koji were analyzed using 16S rRNA gene sequencing based on Illumina MiSeq high-throughput technology in 20 samples collected from Xiaogan area, Hubei province and Dazhu area, Sichuan province (10 from each area). We found rice wine koji flora mainly consisted of Weissella, Lactobacillus, Lactococcus, Bacillus, Enterococcus, and Cronobacter, with relative abundances of 29.49%, 10.93%, 8.85%, 4.75%, 1.16% and 1.15%, respectively, as well as an accumulative average relative abundance of 58.71%. They all belonged to Firmicutes and Proteobacteria—the two known dominant genus. Genus-level PCA (Principal component analysis) and OTU-level PCoA (Principal coordinates analysis) based on unweighted UniFrac distances showed that the bacterial community structure differed significantly between the samples from the 2 areas. 7 OTUs were detected in all samples, accounting for 4.4% of the total qualified assembly. Among the 7 OTUs, 3 OTUs were identified as Enterococcus, 2 OTUs were identified as Cronobacter, 1 OTU was identified as Bacillus and 1 OTU was identified as Alkaliphilus. Fifty-eight lactic acid bacteria (LAB) strains were isolated from the 20 koji samples with traditional microbial methods. Among them, Enterococcus faecium and Pediococcus pentosaceus were the dominant LAB isolates, with relative abundances of 51.72% and 31.03%. Despite the differences, a large number of shared bacteria were detected in samples from the two areas. [ABSTRACT FROM AUTHOR]

Sea buckthorn has been proved to be a good substrate for lactic acid bacteria (LAB), but the research on the fermentation of sea buckthorn juice (SBJ) by LAB is still rare. This study was designed to determine the performance of fermented SBJ (FSBJ) in four LAB and investigate the sensory aspects of FSBJ. The results showed that the utilization rates of reducing sugar, titratable acid, and malic acid of SBJ fermented by Lactobacillus casei (SBJLc) were the highest and that lactic acid content was the greatest. The organic acid compositions of the four kinds of FSBJs were also different. The viable counts of all FSBJs was greater than 7 log CFU/mL, and that the viable count of SBJ fermented by SBJLc was the highest. In this study, the Electronic tongue combined with Electronic nose was used for the first time to study SBJ. Results showed that compared with the control, the response value of Sourness was significantly increased, while Bitterness and Astringency were significantly decreased. There was a significant difference in four FSBJs. The results of the electronic nose showed that SBJ fermented by Lactobacillus plantarum LP56 (SBJLp) could be well identified by sensors sensitive to aromatic substances. The volatile compound contents before and after fermentation were significantly different, the highest being SBJLp. Finally, the results of sensory evaluation experiments showed that SBJLp was the most acceptable to consumers in terms of sensory evaluation. [ABSTRACT FROM AUTHOR]

Jujube juice was separately undergoing controlled lactic acid fermentation at 37°C for 24 hr with 90 different lactic acid bacteria (LAB) strains comprising 30 Lactobacillus casei strains, 30 Lactobacillus plantarum strains, and 30 Enterococcus faecium strains. Electronic nose and Electronic tongue combined with multivariate statistical analysis methods were applied for the investigation of how different LAB strains affecting the flavor profile of fermented jujube juice. A clear distinction of all the fermented jujube juice was achieved. It was found that compared with L. casei‐fermented jujube juice and E. faecium‐fermented jujube juice, L. plantarum‐fermented jujube juice produce more aromatics compounds and less sulfur organic compounds, while its taste is mostly characterized by sourness, and is perceived less bitterness and astringent for better consumer preference. What's more, the high acid‐producing ability of L. plantarum may contribute to an extension of microbial safety and shelf life for the product. Practical applications: L. plantarum is considered as a microorganism with a documented history of food use with the generally recognized as safe (GRAS) status from the US Food and Drug Administration (US FDA) and the qualified presumption of safety (QPS) status from the European Food Safety Authorities (EFSA). Based on the findings of this research, L. plantarum could improve the flavor profile of the jujube juice and may contribute to an extension of microbial safety and shelf life for the product leads to antibacterial an excellent potential for future research and development. [ABSTRACT FROM AUTHOR]

To investigate the bacterial profiles and taste characteristics of rice wine from the Xiaogan and Dazhou regions, this study employed a combination of High-throughput sequencing, traditional pure culture techniques, and bionics equipment. The findings revealed a significant difference (P < 0.05) in bacterial diversity and community structure between the rice wine from Xiaogan and Dazhou. In particular, Leuconostoc , Lactococcus , Lacticaseibacillus , Exiguobacterium , Gluconobacter , Streptococcus , and Pantoea were significantly enriched in Xiaogan rice wine, Limosilactobacillus , Pediococcus , and Lactobacillus were significantly enriched in Dazhou rice wine. Notably, the most dominant group of bacteria in rice wine was lactic acid bacteria (LAB), and the main culturable isolates were Limosilactobacillus fermentum and Pediococcus pentosaceus. Additionally, the dominant bacterial genera showed a significant correlation with the taste characteristics of rice wine. Limosilactobacillus , Pediococcus , Lactobacillus , and Pseudomonas were positively correlated with the lactic acid, citric acid, pH value, Ala, Ile, and Leu of rice wine. Meanwhile, Exiguobacterium , Lacticaseibacillus , and Streptococcus were positively correlated with the richness of rice wine. This study provides insights into the bacterial diversity and taste characteristics of rice wine from different regions of the Yangtze River Basin and highlights the potential of traditional fermented foods as resources for LAB. • Bacterial communities in rice wines from different regions differed significantly. • Mainly lactic acid bacteria were isolated from traditionally fermented rice wine. • A relationship was found between the bacteria and taste characteristics in rice wine. [ABSTRACT FROM AUTHOR]

In this study, 11 strains of lactic acid bacteria (LAB) from 4 species were comprehensively characterized for their ability to improve the functional properties and flavor quality of jujube–wolfberry composite juice. The results revealed that the jujube–wolfberry fresh juice was a favorable substrate for LAB growth, and the total number of LAB colonies remained above 7.93 log CFU/mL after fermentation. Fermentation with Lactiplantibacillus plantarum 9-2 (LP9-2) increased the total phenolic content by 16.67% and reduced the total flavonoid content by 14.15%; correspondingly, the antioxidant capacity significantly increased (p < 0.05) and was positively correlated with the content of gallic acid and rutin. In total, 56 volatile compounds were identified and quantified from the fermented juice. In total, 11 volatile compounds with relative odor activity value ≥ 1 were identified. In particular, LP9-2 increased the levels of (E)-2-hexenal, hexanal, and benzaldehyde, which resulted in an enhanced "jujube and wolfberry" flavor in the final product. • Fermentation enhances the antioxidant activity of jujube-wolfberry composite juice. • Lactic acid bacteria fermentation increased the content of acid, alcohol and ester. • A total of 56 volatile compounds were identified and quantified. • A total of 11 key volatile compounds with rOAV >1 were identified. [ABSTRACT FROM AUTHOR]

In this study, we comparatively analyzed the microbial community structure of light-flavored Daqu (LFD) from Taiyuan and Suizhou regions using a combined strategy of single-molecule real-time sequencing and pure culture techniques. The results indicated that the dominant bacteria and fungi in all LFD were Bacillus licheniformis (22.61%) and Saccharomycopsis fibuligera (80.98%), respectively. The abundance and diversity of fungi were significantly lower in the LFD from Taiyuan region (Taiyuan-LFD) (p < 0.05). The LFD from both regions exhibited differences mainly in terms of lactic acid bacteria and thermophilic flora; Leuconostoc were significantly enriched in the Taiyuan-LFD, whereas Weissella , Thermoascus aurantiacus , and Thermoactinomyces sanguinis were significantly enriched in the LFD from Suizhou region (Suizhou-LFD) (p < 0.05). The correlating network between the microbiota of the Suizhou-LFD was denser than the Taiyuan-LFD. The core microorganisms of the LFD in both regions were mainly Ba. licheniformis , Burkholderia contaminans , and Saccharomycopsis fibuligera. Bacillus , lactic acid bacteria, and yeast isolated from all samples mainly consisted Ba. licheniformis (28 strains), Pediococcus pentosaceus (22 strains), and Saccharomycopsis fibuligera (44 strains), respectively. This study provided insights into the variations in microbiota in the LFD from different regions and laid the foundation for screening excellently suited functional microorganisms for brewing. • The microbial community in the light-flavor Daqu of Taiyuan and Suizhou regions was fully revealed. • The fungal diversity and abundance of the LFD in the Taiyuan region were lower than LFD in the Suizhou region. • Bacillus licheniformis and Saccharomycosis fibulifera were the main core flora of LFD in two regions. [ABSTRACT FROM AUTHOR]

[Display omitted] • Peak temperature affects microbiota, functions and flavor of low-temperature Daqu. • Each type of low-temperature Daqu contributed to the flavor of light-flavor Baijiu. • The taste profiles of different types of low-temperature Daqu differed more. • Bacteria mainly affected the taste, while fungi mainly affected the aroma. Light-flavor Baijiu is made from grain materials using a combination of three types of low-temperature Daqu (Hongxin, Houhuo, and Qingcha). This study comprehensively examined the microbial structure, microbial functions, and flavor characteristics of the three types of low-temperature Daqu using high-throughput sequencing and electronic senses, and it further clarified the relationship between the microbiota and flavor in low-temperature Daqu. The results showed that Hongxin had the highest bacterial richness and diversity, while Houhuo had the lowest. Both fungal richness and diversity were significantly higher in Qingcha than in Hongxin and Houhuo. The differences in peak temperature during Daqu-making led to significant differences in the structure of microbial communities, microbial functions, and flavor quality in the three types of low-temperature Daqu, and could be leveraged for screening and enriching functional microorganisms for Baijiu-making. Co-exclusion patterns between lactic acid bacteria and Bacillus in low-temperature Daqu resulted in a negative correlation between amino acid transport metabolism and carbohydrate transport metabolism. The different types of low-temperature Daqu had distinct flavor profiles, and the differences in the taste profiles were more significant. Dominated by Thermoactinomyces and Lactobacillus , and together with Saccharopolyspora , Bacillus , Streptomyces , Saccharomycopsis , and Thermoascus , they formed the core microbiota that influencing the flavor of low-temperature Daqu. The bacteria mainly influenced the taste of low-temperature Daqu, whereas the fungi mainly influenced the aroma. Each type of low-temperature Daqu contributed to the flavor of light-flavor Baijiu: Hongxin could elevate the levels of aromatic compounds, Houhuo could regulate the bitterness and sourness, and Qingcha could inhibit the generation of sulfur organic compounds. The results of the present study enrich and refine our knowledge of low-temperature Daqu, promoting the further evolution of traditional brewing methods. [ABSTRACT FROM AUTHOR]

[Display omitted] • Lactic acid bacteria dominate in zha-chili and have a great impact on the quality. • Different rice varieties lead to differences in microbiota and flavor. • The differences in microbiota mainly affect the sourness and umami of zha-chilli. • Relationships among rice varieties, bacterial microbiota and flavor were clarified. The structure and diversity of bacterial communities in spontaneously fermented zha-chili prepared using two different rice varieties (glutinous rice and indica rice) were investigated using high-throughput sequencing. Through metabolic pathway prediction, electronic senses and metabolite analysis, the relationships among the rice varieties used for preparation and the bacterial microbiota, flavor, and organic acid/amino acid metabolites in zha-chili were elucidated. We observed that the structure of bacterial communities in zha-chili samples differed significantly with the rice variety used during fermentation (p < 0.05), and that there was a greater abundance of bacterial species in zha-chili prepared using glutinous rice. Lactic acid bacteria were predominant in zha-chili, with an average relative abundance of 77.09%. The aroma of zha-chili was influenced by the raw material itself, while the characteristic tastes of zha-chili — including sourness, umami and richness — were significantly correlated with the bacterial microbiota. In addition, the abundance of lactic acid bacteria was positively correlated with the levels of organic acids and negatively correlated with the levels of amino acids. This also made the zha-chili prepared using glutinous rice sourer and imparted more umami taste to the zha-chili prepared using indica rice. Our observations provide a reference for the evaluation of zha-chili quality and could effectively guide the improvement of zha-chili products. [ABSTRACT FROM AUTHOR]