Proteiniclasticum sediminis sp. nov., an obligate anaerobic bacterium isolated from anaerobic sludge

An obligate anaerobic bacterial BAD-10 T was isolated from anaerobic acetochlor-degrading sludge. The strain was Gram-stain negative, curved rod-shaped, non-motile and non-spore-forming. Growth was observed in PYT medium at pH 6.0–9.0 (optimum, pH 7.5), at 25–47 °C (37 °C) and with 0–1.0% NaCl (w/v, 0%). Strain BAD-10 T could degrade acetochlor. The major fermentation products from peptone-yeast (PY) medium were acetate and butyrate. The predominant cellular fatty acids were iso-C 15:0 FAME, anteiso-C 15:0 FAME and C 16:0 FAME. Phylogenetic analysis based on 16S rRNA gene sequences revealed that the strain BAD-10 T showed closest affiliation to Proteiniclasticum ruminis D3RC-2 T , with a sequence similarity of 97.6%. Genome sequencing revealed a genome size of 2,983,986 bp, a G + C content of 51.4 mol% and protein-coding genes of 3,102. The average nucleotide identity and in silico DNA–DNA hybridization values between strain BAD-10 T and Proteiniclasticum ruminis D3RC-2 T were 71.0% and 20.4%, respectively, which were below the standard thresholds for species differentiation. On the basis of phenotypic, physiological and phylogenetic evidence, strain BAD-10 T represents a novel species in the genus Proteiniclasticum , for which the name Proteiniclasticum sediminis sp. nov. is proposed. Strain BAD-10 T (= CCTCC AB 2021091 T = KCTC 25288 T ) is the type strain of the proposed novel species.