Genome sequence and description of Blautia brookingsii str SG772 nov., a new species of anaerobic bacterium isolated from healthy human gut

Abstract

Strain SG-772 is a Gram positive, strictly anoxic bacterium isolated from the feces of a healthy human fecal donor. Based on 16S rRNA gene sequence, the strain showed maximum similarity (94.39%) with Blautia stercoris GAM6-1 in EZ-Taxon server and thus assigned the genus Blautia. The scanning electron micrograph of the bacterium revealed the characteristic coccobacillus shape as well as the complete absence of flagellum, suggesting its non-motile phenotype. This strain was found to utilize 27 substrates based on Biolog AN plates assay, with maximum preference for D-mannitol. Additionally, the strain was found to be resistant to tetracycline and streptomycin. Genome sequencing and analysis revealed an overall genome size of 3.49 Mbp and GC content of 43.97%. Based on RAST annotation server, the closest neighbor was Blautia hansenii DSM20583. Average Nucleotide Identity (ANI) of these strains were 81.69%, suggesting a high level of genomic variation. The comparative genome analysis of strain SG772 with B. hansenii DSM20583 revealed a total of 411 orthologous genes coding for basic metabolic functions. Furthermore, the genomes were functionally distinct based on COG categories. Thus, based on all these differences, we propose a novel species of genus Blautia named as Blautia brookingsii SG772.