The headspace solid-phase microextraction combined with gas chromatography-mass spectrometry(HS-SPME-GC-MS) and high-throughput sequencing were used to investigate the relationship between Scopulibacillus and Daqu flavor. The results showed that the abundance of Scopulibacillus increased significantly with the deepening color of Daqu, and Scopulibacillus had a significantly positive correlation with six flavor compounds. A pure strain of Scopulibacillus daqui LBM32026 was isolated from the black Daqu, and the growth characteristics and flavor metabolism of the strain were analyzed at different temperatures. It was found that it grew rapidly at 50 and 60 ℃, but grew slowly or even inhibited at 30 ℃ and 40 ℃. A total of 40 volatile compounds, including 8 alcohols, 2 esters, 3 acids, 8 nitrogenous, 7 aromatics, 4 phenols, 5 aldehydes, 1 ketone, 1 lactone and 1 other compound, were detected in the solid-state fermentation of monobacteria. This research contributes to the study of thermophilic microorganisms in high-temperature Daqu and provides a theoretical basis for their future production application in the Daqu production process.
[1] DIMIDI E, COX S R, ROSSI M, et al.Fermented foods:Definitions and characteristics, impact on the gut microbiota and effects on gastrointestinal health and disease[J].Nutrients, 2019, 11(8):1806.
[2] JIN G Y, ZHU Y, XU Y.Mystery behind Chinese liquor fermentation[J].Trends in Food Science & Technology, 2017, 63:18-28.
[3] 范文来, 徐岩.酱香型白酒中呈酱香物质研究的回顾与展望[J].酿酒, 2012, 39(3):8-16.
FAN W L, XU Y.Current practice and future trends of key aroma compounds in Chinese soy sauce aroma type liquor[J].Liquor Making, 2012, 39(3):8-16.
[4] DUAN J W, YANG S Q, LI H H, et al.Why the key aroma compound of soy sauce aroma type Baijiu has not been revealed yet?[J].LWT, 2022, 154:112735.
[5] ZHANG Y D, DING F, SHEN Y, et al.Characteristics of the microbiota and metabolic profile of high-temperature Daqu with different grades[J].World Journal of Microbiology and Biotechnology, 2022, 38(8):137.
[6] WANG Y R, CAI W C, WANG W P, et al.Analysis of microbial diversity and functional differences in different types of high-temperature Daqu[J].Food Science & Nutrition, 2020, 9(2):1003-1016.
[7] 吴盛露, 杜海, 徐岩.生物热对传统固态发酵菌群演替及其代谢影响的研究进展[J].微生物学通报, 2022, 49(6):2281-2294.
WU S L, DU H, XU Y.Effect of bio-heat on microbial succession and metabolism in traditional solid-state fermentation:A review[J].Microbiology China, 2022, 49(6):2281-2294.
[8] XIAO C, LU Z M, ZHANG X J, et al.Bio-heat is a key environmental driver shaping the microbial community of medium-temperature Daqu[J].Applied and Environmental Microbiology, 2017, 83(23):e01550-e01517.
[9] HE G Q, DONG Y, HUANG J, et al.Alteration of microbial community for improving flavor character of Daqu by inoculation with Bacillus velezensis and Bacillus subtilis[J].LWT, 2019, 111:1-8.
[10] XU B Y, XU S S, CAI J, et al.Analysis of the microbial community and the metabolic profile in medium-temperature Daqu after inoculation with Bacillus licheniformis and Bacillus velezensis[J].LWT, 2022, 160:113214.
[11] YANG Y, ZOU Y F, ZENG K J, et al.Effect of Bacillus subtilis fortified inoculation on the microbial communities in different niches of Daqu[J].Journal of Bioscience and Bioengineering, 2022, 134(5):407-415.
[12] YAO S, ZHAI L, XIN C H, et al.Scopulibacillus daqui sp.nov., a thermophilic bacterium isolated from high temperature Daqu[J].International Journal of Systematic and Evolutionary Microbiology, 2016, 66(11):4723-4728.
[13] ZHANG H X, DU H, XU Y.Volatile organic compound-mediated antifungal activity of Pichia spp.and its effect on the metabolic profiles of fermentation communities[J].Applied and Environmental Microbiology, 2021, 87(9):e02992-e02920.
[14] WANG X S, DU H, ZHANG Y, et al.Environmental microbiota drives microbial succession and metabolic profiles during Chinese liquor fermentation[J].Applied and Environmental Microbiology, 2018, 84(4):e02369-e02317.
[15] YANG L, FAN W L, XU Y.GC × GC-TOF/MS and UPLC-Q-TOF/MS based untargeted metabolomics coupled with physicochemical properties to reveal the characteristics of different type daqus for making soy sauce aroma and flavor type Baijiu[J].LWT, 2021, 146:111416.
[16] WANG P, WU Q, JIANG X J, et al.Bacillus licheniformis affects the microbial community and metabolic profile in the spontaneous fermentation of Daqu starter for Chinese liquor making[J].International Journal of Food Microbiology, 2017, 250:59-67.
[17] ZHU C T, CHENG Y X, ZUO Q C, et al.Exploring the impacts of traditional crafts on microbial community succession in Jiang-flavored Daqu[J].Food Research International, 2022, 158:111568.
[18] SHI W, CHAI L J, FANG G Y, et al.Spatial heterogeneity of the microbiome and metabolome profiles of high-temperature Daqu in the same workshop[J].Food Research International, 2022, 156:111298.
[19] KOEHLER P E, ODELL G V.Factors affecting the formation of pyrazine compounds in sugar-amine reactions[J].Journal of Agricultural and Food Chemistry, 1970, 18(5):895-898.
[20] YAN Y, CHEN S, NIE Y, et al.Quantitative analysis of pyrazines and their perceptual interactions in soy sauce aroma type Baijiu[J].Foods, 2021, 10(2):441.
[21] 于海燕, 姚文倩, 陈臣, 等.内酯类化合物在食品中的风味贡献及形成机制[J].现代食品科技, 2022, 38(5):337-349;55.
YU H Y, YAO W Q, CHEN C, et al.Flavor contribution and biosynthesis mechanism of lactone compounds in food[J].Modern Food Science and Technology, 2022, 38(5):337-349;55.
[22] 王勇, 徐岩, 范文来, 等.应用GC-O技术分析牛栏山二锅头白酒中的香气化合物[J].酿酒科技, 2011(2):74-76;79.
WANG Y, XU Y, FAN W L, et al.Determination of aroma compounds in Niulanshan Erguotou liquor by GC-O[J].Liquor-Making Science & Technology, 2011(2):74-76;79.
