Qipengyuania marincola sp. nov., Qipengyuania flavescens sp. nov. and Pseudoblastomonas aquimaris sp. nov., three novel members of the family Erythrobacteraceae isolated from seawater

Abstract

Three Gram-stain-negative, aerobic, rod-shaped, non-motile and orange-pigmented bacteria, designated as XHP0207^T, XHP0211^T and WL0013^T, were isolated from surface seawater collected from Nantong City, the Yellow Sea of China. Cells were positive for catalase and oxidase. These strains were all optimally grown at 28 ℃, pH 7.0 and 3% (w/v) NaCl and possessed Q-10 as the respiratory quinone. The 16S rRNA gene sequence analysis indicated that strains XHP0207^T, XHP0211^T and WL0013^T showed the highest sequence similarity to Qipengyuania profundimaris G39^T (99.0%), Q. profundimaris G39^T (100%) and Alteriqipengyuania flavescens SCSIO 75105^T (100%), respectively. However, a phylogenetic tree based on the 288 orthologous clusters indicated that both XHP0207^T and XHP0211^T were closely related to Qipengyuania proteolytica 6B39^T, and WL0013^T was closely related to Alterqipengyuania flavescens SCSIO 75105^T. The average nucleotide identity, average amino acid identity and digital DNA-DNA hybridization values among strains XHP0207^T, XHP0211^T and WL0013^T and closely related type strains were all below the species delineation cutoffs of 95%, 95% and 70%, respectively, though the values exceeded between strain XHP0207^T and a non-type strain. The genomic DNA G+C contents of strains XHP0207^T, XHP0211^T and WL0013^T were 63.0%, 63.0% and 65.5%, respectively. Based on the phenotypic, phylogenetic and chemotaxonomic characterizations, strains XHP0207^T and XHP0211^T represent two novel Qipengyuania species, and we thus propose the names Qipengyuania marincola sp. nov. (type strain, XHP0207^T=MCCC 1K07527^T=GDMCC 1.3090^T=JCM 35571^T) and Qipengyuania flavescens sp. nov. (type strain, XHP0211^T=MCCC 1K07528^T=GDMCC 1.3091^T=JCM 35572^T). Strain WL0013^T represents a novel Pseudoblastomonas species, for which the name Pseudoblastomonas aquimaris sp. nov. (type strain, WL0013^T=JCM 34654^T=GDMCC1.2439^T) is proposed. In addition, Alterqipengyuania flavescens is reclassified as Pseudoblastomonas flavescens comb. nov. (type strain, KCTC 92502^T=MCCC 1K07993^T=SCSIO 75105^T).

Keywords: Alteriqipengyuania; Pseudoblastomonas; Qipengyuania; astaxanthin; photosynthesis gene cluster (PGC).