Hydrogenophaga aromaticivorans sp. nov., isolated from a para-xylene-degrading enrichment culture, capable of degrading benzene, meta- and para-xylene

Abstract

A benzene, para- and meta-xylene-degrading Gram-stain-negative, aerobic, yellow-pigmented bacterium, designated as D2P1T, was isolated from a para-xylene-degrading enrichment culture. Phylogenetic analyses based on 16S rRNA genes showed that D2P1T shares a distinct phyletic lineage within the genus Hydrogenophaga and shows highest 16S rRNA gene sequence similarity to Hydrogenophaga taeniospiralis NBRC 102512T (99.2 %) and Hydrogenophaga palleronii NBRC 102513T (98.3 %). The draft genome sequence of D2P1T is 5.63 Mb long and the genomic DNA G+C content is 65.5 %. Orthologous average nucleotide identity (OrthoANI) and digital DNA–DNA hybridization (dDDH) analyses confirmed low genomic relatedness to its closest relatives (OrthoANI <86 %; dDDH <30 %). D2P1T contains ubiquinone 8 (Q-8) as the only respiratory quinone and phospholipid, phosphatidylglycerol, phosphatidylethanolamine, diphosphatidylglycerol as major polar lipids. The main whole-cell fatty acids of D2P1T are summed feature 3 (C16 : 1  ω7c/C16 : 1  ω6c), C16 : 0 and summed feature 8 (C18 : 1  ω7c/C18 : 1  ω6c). The polyphasic taxonomic results indicated that strain D2P1T represents a novel species of the genus Hydrogenophaga , for which the name Hydrogenophaga aromaticivorans sp. nov. is proposed. The type strain is D2P1T (=LMG 31780T=NCAIM B 02655T).