Isolation and identification of acetoin-producing strain and its effect on solid-state multi-microbial fermentation products
Acetoin(ACT)is a key precursor of tetramethylpyrazine(TTMP),an important functional substance in Baijiu.Acetoin-producing strains were screened and isolated from sauce-flavor Daqu,identified by morphological observation and molecular biology techniques,and applied to solid-state multi-microbial fermentation to investigate their effects on physicochemical indexes,organic acids,and volatile flavor compounds of fermentation products.The results showed that an acetoin-producing strain A12F_C118 was isolated and screened,and identified as Bacillus sonorensis.The moisture reducing sugar,total acid contents,and pH of the multi-microbial fermentation products with strain A12F_C118 addition increased by 39.40％,38.46％,127.63％,and 11.93％,respectively compared with the blank group.A total of 51 volatile flavor compounds were detected in the multi-microbial fermen-tation products with strain A12F_C118 addition,among them,the contents of important flavor compounds such as 1-pentanol,ethyl phenylacetate,ethyl caproate,tetramethylpyrazine,2,5-dimethylpyrazine and trimethylpyrazine increased.Strain A12F_C118 could promote the synthesis of oxalic acid,L-malic acid,L-lactic acid,acetic acid and citric acid during solid-state multi-microbial fermentation,but its effect on succinic acid was not significant.
acetoinisolation and identification of strainsolid-state multi-microbial fermentationpyrazinesphysicochemical indexorganic acidflavor componet
万方数据
维普
