Niastella caeni sp. nov., isolated from activated sludge

Abstract

A Gram-stain-negative, aerobic, non-flagellated and filamentous-shaped bacterium, HX-16-21T, was isolated from activated sludge. Strain HX-16-21T was able to degrade gentisate, protocatechuic acid and p-hydroxybenzoic acid and herbicides quizalofop-p-ethyl and diclofop-methyl. The strain shared 97.2 % 16S rRNA gene sequence similarity to Niastella vici CCTCC AB 2015052T and less than 97 % similarities to other type strains. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain HX-16-21T belonged to the genus Niastella and formed a subclade with N. vici CCTCC AB 2015052T. The major polar lipids were phosphatidylethanolamine, phosphatidylcholine and six unidentified lipids. The major fatty acids were iso-C15:0, iso-C15:1 G and iso-C17:0 3-OH. The predominant respiratory quinone was menaquinone 7 (MK-7). The draft genome of strain HX-16-21T was 8.1 Mb, and the G+C content was 43.5 mol%. The average nucleotide identity and digital DNA–DNA hybridization values between strain HX-16-21T and N. vici CCTCC AB 2015052T were 80.6 and 26.8 %, respectively. Based on both phenotypic and phylogenetic evidence, strain HX-16-21T is considered to represent a novel species in the genus Niastella , for which the name Niastella caeni sp. nov. is proposed. The type strain is HX-16-21T (=KCTC 72288T=ACCC 61580T).