Genome Sequence Analysis of Clostridium tyrobutyricum, a Promising Microbial Host for Human Health and Industrial Applications.

Clostridium tyrobutyricum is a promising microbial host for the anaerobic production of bio-based chemicals, especially butyric acid. At the same time, it also has great potential as a probiotic for the production of short-chain fatty acids in the intestines. However, due to the insufficient knowledge of the genetic characteristics of this organism, there has been little progress in its genetic engineering to date. Here, we present the complete genome sequence of C. tyrobutyricum L319, which consists of a circular chromosome and a plasmid with a G + C content of 31.69%, encompassing approximately 3.09 Mb with 3052 protein-coding genes. Functional gene annotation revealed better results than previous studies based on KEGG pathway classification. Furthermore, we obtained detailed functional characterization of 93 genes previously annotated as putative proteins. Genomic analysis revealed that this organism contains multiple genes encoding enzymes involved in the CRISPR-Cas systems, substrate utilization, isopeptide and ester bonds, transcriptional regulation, and oxidative stress. The safety evaluation at genetic level indicated that this organism does not possess transferable resistance genes, invasive defensive pathogenicity factors, or harmful enzymes. The genome sequence data analyzed in this study will be available for further research and will facilitate the further understanding and development of potential applications of C. tyrobutyricum.