Phocaeicola acetigenes sp. nov., producing acetic acid and iso-butyric acid, isolated faeces from a healthy human

Abstract

An obligately anaerobic, non-motile, Gram-stain-negative, and rod-shaped strain KGMB11183^T was isolated from the feces of healthy Koreans. The growth of strain KGMB11183^T occurred at 30–45 °C (optimum 37 °C), at pH 6–9 (optimum pH 7), and in the presence of 0–0.5% NaCl (optimum 0%). Strain KGMB11183^T showed 16S rRNA gene sequence similarities of 95.4% and 94.2% to the closest recognized species, Phocaeicola plebeius M12^T, and Phocaeicola faecicola AGMB03916^T. Phylogenetic analysis showed that strain KGMB11183^T is a member of the genus Phocaeiocla. The major end products of fermentation are acetic acid and isobutyric acid. The major cellular fatty acids (> 10%) of this isolate were C_18:1 cis 9, anteiso-C_15:0, and summed feature 11 (iso-C_17:0 3-OH and/or C_18:2 DMA). The assembled draft genome sequences of strain KGMB11183^T consisted of 3,215,271 bp with a DNA G + C content of 41.4%. According to genomic analysis, strain KGMB11183^T has a number of genes that produce acetic acid. The genome of strain KGMB11183^T encoded the starch utilization system (Sus) operon, SusCDEF suggesting that strain uses many complex polysaccharides that cannot be digested by humans. Based on the physiological, chemotaxonomic, phenotypic, and phylogenetic data, strain KGMB11183^T is regarded a novel species of the genus Phocaeicola. The type strain is KGMB11183^T (= KCTC 25284^T = JCM 35696^T).