Paracoccus jiaweipingae sp. nov. and Paracoccus zhouxuedongae sp. nov., isolated from blowhole swab samples of Yangtze finless porpoise (Neophocaena asiaeorientalis asiaeorientalis)

Four novel strains, designated p1-h21^T/p2-l61 and p3-h83^T/p4-l81, characterized as Gram-stain-negative, oxidase-positive, catalase-positive, obligately aerobic, non-motile and rod-shaped, isolated from blowhole swab samples of Yangtze finless porpoise (<i>Neophocaena asiaeorientalis asiaeorientalis</i>), collected from Hubei Province, China. Pairwise sequence comparisons of the 16S rRNA genes showed that these isolates were separated into two species. Strains p1-h21^T and p2-l61 were most closely related to <i>Paracoccus endophyticus</i> SYSUP0003^T (97.18% similarity) and <i>Paracoccus aurantiacus</i> TK008^T (97.03% similarity), whereas strains p3-h83^T and p4-l81 exhibited 96.89% similarity to <i>Paracoccus kondratievae</i> GB^T, and 96.53% similarity to <i>Phaeovulum vinaykumarii</i> DSM 18714^T. The DNA G+C contents of type strains p1-h21^T and p3-h83^T are 65.7 mol% and 66.9 mol%, respectively. These strains had summed feature 8 (comprising C_{18 : 1} <i> ω</i>6<i>c</i> and/or C_{18 : 1} <i> ω</i>7<i>c</i>) as major cellular fatty acids, ubiquinone 10 as the sole respiratory quinone and diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine and phosphatidylcholine as major polar lipids, which are typical for members of the genus <i>Paracoccus</i>. However, the average nucleotide identity (ANI) and digital DNA-DNA hybridization (dDDH) values between the four novel strains and their reference strains (ANI <75.3%, dDDH <20.5%) are lower than the species delineation thresholds, along with distinct phenotypic and biochemical characteristics, distinguishing them from their closest relatives and other recognized <i>Paracoccus</i> species. Therefore, strains p1-h21^T/p2-l61 and p3-h83^T/p4-l81 represent two novel species in the genus <i>Paracoccus</i>, for which the names <i>Paracoccus jiaweipingae</i> sp. nov. and <i>Paracoccus zhouxuedongae</i> sp. nov. are proposed, with p1-h21^T (=GDMCC 1.4971^T=JCM 37697^T) and p3-h83^T (=GDMCC 1.4972^T=JCM 37698^T) as type strains.