Analysis of TTMP Biosynthesis Relation Genes in Bacillus velezensis CS1.13 and Its Fermentation Regulation
In order to characterize the biosynthetic pathway of 2,3,5,6-Tetramethylpyrazine(TTMP)in Bacillus spp.,the whole-genome information of Bacillus velezensis CS1.13 screened from high-salt liquid-state moromi was annotated,and its TTMP biosynthetic pathway and regulatory characteristics were studied in combination with solid-state fermenta-tion.The results show that CS1.13 is rich in genes involved in amino acid metabolism and transport,carbohydrate metabolism and transport and coding glycoside hydrolase by COG,GO and carbohydrate active enzyme annotations.And KEGG annotation reveals that CS1.13 has a complete metabolic pathway of Acetoin,a key substrate of TTMP.The sol-id-state fermentation process revealed that the reducing sugar and amino acid nitrogen contents increased by 53.63 g/kg and 8.28 g/kg,respectively,and TTMP accumulated 159.86 mg/kg at 72 h of fermentation,which proved that CS1.13 has good carbon and nitrogen metabolism ability and TTMP synthesis potential.According to the TTMP synthesis path-way,the key substances such as threonine,acetic acid,pyruvic acid and 2,3-butanediol were selected to study the regulation of TTMP biosynthesis.The maximum accumulation of TTMP was achieved when threonine 2mg/g,acetic acid 0.2 mg/g,pyruvic acid 0.2 mg/g and 2,3-butanediol 0.8 mg/g were added respectively,which increased 32.82％,10.30％,222.46％and 160.93％compared with the control sample.The accumulation of TTMP decreased as the content of the above additive increased.In addition to the amino donor threonine,the accumulation of the three pyrazines(TTMP,2,5-dimethylpyrazine and 2,3,5-trimethylpyrazine)was favored by the lower concentrations of carbon skeleton donors acetate,pyruvic acid or 2,3-butanediol,and the accumulation of butanedione family compounds was favored by excessive carbon skeleton donors instead,suggesting that the synthesis of TTMP was regulated by the amino donor and carbon skeleton donor.The analysis of TTMP biosynthesis relation genes combined with fermentation regulation explored a feasible and effective way for Bacillus velezensis CS1.13 to accumulate TTMP efficiently,which will also lay the founda-tion for its application in rapid aroma enhancement in Jiang-flavor foods.
万方数据
维普
