Characterization a Novel Butyric Acid-Producing Bacterium Collinsella aerofaciens Subsp. Shenzhenensis Subsp. Nov.

Butyrate-producing bacteria can biosynthesize butyrate and alleviate inflammatory diseases. However, few studies have reported that the genus <i>Collinsella</i> has the ability to produce butyric acid. Here, our study depicts a <i>Collinsella</i> strain, which is a rod-shaped obligate anaerobe that is able to produce butyric acid. This microorganism was isolated from a human gut, and the optimal growth conditions were found to be 37 °C on PYG medium with pH 6.5. The 16S rRNA gene sequence demonstrated that this microorganism shared 99.93% similarity with <i>C</i>. <i>aerofaciens</i> ATCC 25986^T, which was higher than the threshold (98.65%) for differentiating two species. Digital DNA⁻DNA hybridization and average nucleotide identity values also supported that this microorganism belonged to the species <i>C. aerofaciens</i>. Distinct phenotypic characteristics between TF06-26 and the type strain of <i>C</i>. <i>aerofaciens</i>, such as the fermentation of D-lactose, D-fructose and D-maltose, positive growth under pH 5 and 0.2% (<i>w</i>/<i>v</i>) cholate, suggested this strain was a novel subspecies. Comparative genome analysis revealed that butyric acid kinase and phosphate butyryltransferase enzymes were coded exclusively by this strain, indicating a specific butyric acid-producing function of this <i>C</i>. <i>aerofaciens</i> subspecies within the genus <i>Collinsella</i>. Thus, <i>Collinsella</i> <i>aerofaciens</i> subsp. <i>shenzhenensis</i> subsp. nov. was proposed, with set strain TF06-26^T (=CGMCC 1.5216^T = DSM 105138^T) as the type strain.