生物强化和中间代谢物扰动对四川麸醋微生物群落结构及代谢组分的影响

Effects of bioaugmentation and intermediate metabolite disturbance onmicrobial community and metabolite in Sichuan bran vinegar

中国传统食醋主要采取固态酿造工艺,被广泛用作调味品。该文以四川麸醋为对象,基于Illumina MiSeq测序和多相检测方法,探讨了强化曲和乙醇扰动对微生物群落及代谢组分的影响规律。结果表明,强化曲扰动对细菌群落多样性影响较小,但乙醇扰动后其显著降低。2种扰动方式均显著影响了微生物群落结构,尤其是提高了Lactobacillus和Aspergillus的丰度。此外,强化曲扰动使熟醅四甲基吡嗪、乙偶姻及2,3-丁二酮的含量分别提高了1.36、3.64、3.41倍。多种乙酯类(如苯乙酸乙酯、乳酸乙酯)和醇类(如异戊醇、2,3-丁二醇、苯乙醇)与Sphingomonas、Virgibacillus、Hyphopichia、Rhizomucor和Rhizopus呈正相关。此外,基于PICRUSt2预测,2种扰动使吡嗪类和乳酸代谢途径的关键酶表达上调。该结果为调控四川麸醋微生物群落与代谢以及优化过程参数奠定重要的基础。

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.