Screening and identification of a bacterial strain for the production of tetramethylpyrazine through solid-state fermentation and determination of its high-yield mechanism

In this study, a strain producing a high yield (1.72 mg·g–1) of tetramethylpyrazine (TTMP) was screened under solid-state conditions from high-temperature Daqu and was identified as Bacillus velezensis using 16S rDNA molecular technology. The highest TTMP yield (4.11 mg·g–1) was obtained in the presence of sucrose, when compared to other carbon sources. Subsequently, the high yield molecular mechanism was revealed using transcriptome technology. KEGG (Kyoto Encyclopaedia of Genes and Genomes) annotations indicated that the starch and sucrose metabolism, arginine biosynthesis, fructose and mannose metabolism, and histidine metabolism pathways enhanced TTMP biosynthesis through the generation of more precursors. Key genes involved in TTMP biosynthesis, such as gmuE and argJ, were identified. This study provides a potential strain and approach for enhancing TTMP yield while also deepening the theoretical understanding of the underpinning mechanisms.