Chinese cereal vinegar mainly adopts the solid-state fermentation process and is extensively consumed as an acid condiment. In this study, the impacts of disturbance by fortified Cuqu (starter for vinegar) and ethanol on microbial community and metabolites in Sichuan bran vinegar were explored based on Illumina MiSeq platform and multiphase assay methods. The results indicated that there was a little contribution of fortified Cuqu to the change of bacterial community diversity, which was strongly decreased by ethanol disturbance. The microbial community was significantly affected, in particular, the abundance of Lactobacillus and Aspergillus in Cupei (fermented grain of vinegar) was dramatically enhanced by fortified Cuqu and ethanol. Furthermore, the productions of tetramethylpyrazine, acetoin, and 2,3-butanedione were enhanced by 1.36, 3.64, and 3.41 times, respectively, in matured Cupei via fortified Cuqu. Ethyl esters (ethyl phenylacetate, ethyl lactate, etc.) and alcohols (3-methyl-1-butanol, 2,3-butanediol, phenylethyl alcohol, etc.) were significantly positively related to Sphingomonas, Virgibacillus, Hyphopichia, Rhizomucor, and Rhizopus. In addition, the expressions of enzymes related to the synthesis of pyrazines and lactic acid were up-regulated by two kinds of disturbances. This study provided insight into regulating the microbial community and metabolites, and optimizing the process parameters of Sichuan bran vinegar.
[1] XIA T, ZHANG B, DUAN W H, et al.Nutrients and bioactive components from vinegar:A fermented and functional food[J].Journal of Functional Foods, 2020, 64:103681.
[2] KANDYLIS P, BEKATOROU A, DIMITRELLOU D, et al.Health promoting properties of cereal vinegars[J].Foods(Basel,Switzerland), 2021, 10(2):344.
[3] ZHANG L Q, HUANG J, ZHOU R Q, et al.Evaluating the feasibility of fermentation starter inoculated with Bacillus amyloliquefaciens for improving acetoin and tetramethylpyrazine in Baoning bran vinegar[J].International Journal of Food Microbiology, 2017, 255:42-50.
[4] LIU A P, PENG Y, AO X L, et al.Effects of Aspergillus niger biofortification on the microbial community and quality of Baoning vinegar[J].LWT, 2020, 131:109728.
[5] LIU A P, WANG R, LI J L, et al.Multiple rounds of Aspergillus niger biofortification confer relatively stable quality with minor changes of microbial community during industrial-scale Baoning vinegar production[J].Food Research International, 2021, 150:110768.
[6] CHAI L J, QIU T, LU Z M, et al.Modulating microbiota metabolism via bioaugmentation with Lactobacillus casei and Acetobacter pasteurianus to enhance acetoin accumulation during cereal vinegar fermentation[J].Food Research International, 2020, 138:109737.
[7] PENG M Y, ZHANG X J, HUANG T, et al.Komagataeibacter europaeus improves community stability and function in solid-state cereal vinegar fermentation ecosystem:Non-abundant species plays important role[J].Food Research International, 2021, 150:110815.
[8] JO Y, BAEK J Y, JEONG I Y, et al.Physicochemical properties and volatile components of wine vinegars with high acidity based on fermentation stage and initial alcohol concentration[J].Food Science and Biotechnology, 2015, 24(2):445-452.
[9] ZHENG Y, MOU J, NIU J W, et al.Succession sequence of lactic acid bacteria driven by environmental factors and substrates throughout the brewing process of Shanxi aged vinegar[J].Applied Microbiology ＆ Biotechnology, 2018, 102(6):2 645-2 658.
[10] 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, 111:1-8.
[11] COCCHI M, DURANTE C, GRANDI M, et al.Simultaneous determination of sugars and organic acids in aged vinegars and chemometric data analysis[J].Talanta, 2006, 69(5):1 166-1 175.
[12] ZHANG L Q, ZHOU R Q, CUI R Y, et al.Characterizing soy sauce moromi manufactured by high-salt dilute-dtate and low-salt solid-state fermentation using multiphase analyzing methods[J].Journal of Food Science, 2016, 81(11):C2 639-C2 646.
[13] CHEN X Q, WANG T T, JIN M, et al.Metabolomics analysis of growth inhibition of Lactobacillus plantarum under ethanol stress[J].International Journal of Food Science ＆ Technology, 2020, 55(11):3 441-3 454.
[14] LOURENÇO A B, ROQUE F C, TEIXEIRA M C, et al.Quantitative 1H-NMR-metabolomics reveals extensive metabolic reprogramming and the effect of the aquaglyceroporin FPS1 in ethanol-stressed yeast cells[J].PLoS One, 2013, 8(2):e55439.
[15] ZHANG Q, FU C X, ZHAO C M, et al.Monitoring microbial succession and metabolic activity during manual and mechanical solid-state fermentation of Chinese cereal vinegar[J].LWT, 2020, 133:109868.
[16] WANG Z M, LU Z M, SHI J S, et al.Exploring flavour-producing core microbiota in multi species solid-state fermentation of traditional Chinese vinegar[J].Scientific Reports, 2016, 6:26818.
[17] NIE Z Q, ZHENG Y, XIE S K, et al.Unraveling the correlation between microbiota succession and metabolite changes in traditional Shanxi aged vinegar[J].Scientific Reports, 2017, 7(1):1-12.
[18] LU Z M, LIU N, WANG L J, et al.Elucidating and regulating the acetoin production role of microbial functional groups in multi species acetic acid fermentation[J].Applied and Environmental Microbiology, 2016, 82(19):5 860-5 868.
[19] PATAKOVA P.Monascus secondary metabolites:Production and biological activity[J].Journal of Industrial Microbiology and Biotechnology, 2013, 40(2):169-181.
[20] DE ALMEIDA M N, GUIMARÃES V M, BISCHOFF K M, et al.Cellulases and hemicellulases from endophytic Acremonium species and its application on sugarcane bagasse hydrolysis[J].Applied Biochemistry and Biotechnology, 2011, 165(2):594-610.
[21] CHEN L, ZHAO Z J, YU W, et al.Nutritional quality improvement of soybean meal by Bacillus velezensis and Lactobacillus plantarum during two-stage solid-state fermentation[J].AMB Express, 2021, 11(1):23.
[22] D SANTOS A F, PACHECO C A, VALLE R S, et al.Enzymes produced by halotolerant spore-forming gram-positive bacterial strains isolated from a resting habitat (Restinga de Jurubatiba) in Rio de Janeiro, Brazil:Focus on proteases[J].Applied Biochemistry and Biotechnology, 2014, 174(8):2 748-2 761.
[23] 余宁华, 陆震鸣, 许伟, 等.基于主成分分析的中国发酵食醋有机酸含量差异性分析[J].食品与发酵工业, 2010, 36(10):144-148.
YU N H, LU Z M, XU W, et al.Regional difference of organic acid contents in Chinese fermented vinegar based on principal component analysis[J].Food and Fermentation Industries, 2010, 36(10):144-148.
[24] WU Y F, XIA M L, ZHAO N, et al.Metabolic profile of main organic acids and its regulatory mechanism in solid-state fermentation of Chinese cereal vinegar[J].Food Research International, 2021, 145:110400.
[25] ZHANG L J, CAO Y L, TONG J N, et al.An alkylpyrazine synthesis mechanism involving l-threonine-3-dehydrogenase describes the production of 2,5-dimethylpyrazine and 2,3,5-trimethylpyrazine by Bacillus subtilis[J].Applied and Environmental Microbiology, 2019, 85(24):e01807-e01819.
[26] MENG W, DING F, WANG R M, et al.Enhanced production of tetramethylpyrazine in Bacillus licheniformis BL1 through aldC over-expression and acetaldehyde supplementation[J].Scientific Reports, 2020:3544.
[27] 孙宗保, 尹俊玲, 赵杰文, 等.杂环化合物在镇江香醋陈酿过程中的变化[J].中国食品学报, 2015, 15(6):199-205.
SUN Z B, YIN J L, ZHAO J W, et al.The changes of heterocyclic compounds in Zhenjiang aromatic vinegar during ageing[J].Journal of Chinese Institute of Food Science and Technology, 2015, 15(6):199-205.
[28] LI S, LI P, LIU X, et al.Bacterial dynamics and metabolite changes in solid-state acetic acid fermentation of Shanxi aged vinegar[J].Applied Microbiology and Biotechnology, 2016, 100(10):4 395-4 411.
[29] YIN X Y, ZHONG W K, HUO J, et al.Production of vinegar using edible alcohol as feedstock through high efficient biotransformation by acetic acid bacteria[J].Food Science and Biotechnology, 2017, 27(2):519-524.
