Genomic and Transcriptional Characteristics of Strain Rum-meliibacillus sp. TYF-LIM-RU47 with an Aptitude of Directly Producing Acetoin from Lignocellulose

Rummeliibacillus sp. TYF-LIM-RU47, isolated from the fermentation substrate of grain vinegar, could produce acetoin using a variety of carbon sources, including pentose, hexose and lignocellulose. The draft genome of TYF-LIM-RU47 was constructed and the genomic information revealed that TYF-LIM-RU47 contains genes related to starch and sucrose metabolism, pyruvate metabolism, the oxidative phosphorylation metabolic pathway and lignocellulosic metabolism. The acetoin anabolic pathway of TYF-LIM-RU47 has been deduced from the sequencing results, and acetoin is produced from α-acetolactate via decarboxylation and diacetyl reductase catalytic steps. The results of quantitative real-time PCR tests showed that the synthesis and degradation of acetoin had a dynamic balance in acetoin metabolism, and the transcription of the α-acetolactate synthase gene might exist to the extent of feedback regulation. This study can help researchers to better understand the bioinformation of thermophilic-lignocellulosic bacteria and the mechanisms of the acetoin biosynthesis pathway.