Aurantiacibacter hainanensis sp. nov. and Qipengyuania zhejiangensis sp. nov., two novel Erythrobacteraceae species isolated from tidal flat sediments

Abstract

Two Gram-stain-negative, rod-shaped, non-motile, aerobic and carotenoid-producing strains, belonging to the family Erythrobacteraceae, designated as H149T and Z2T, were isolated from tidal flat sediment samples collected in Hainan and Zhejiang, PR China, respectively. Growth of strain H149T occurred at 15–42 °C, 0–10.0 % (w/v) NaCl, and pH 6.0–8.5, with the optima at 35–37 °C, 3.0–3.5 % (w/v) NaCl and pH 7.0. Strain Z2T grew at 15–37 °C, 0–6.0 % (w/v) NaCl, and pH 6.0–9.5, with the optima at 25–30 °C, 0.5–1.0 % (w/v) NaCl and pH 6.0–6.5. Ubiquinone-10 was the sole ubiquinone in two strains. The predominant cellular fatty acids of strain H149T were C16 : 0, summed feature 3 and summed feature 8, while those of strain Z2T were C17 : 1  ω6c, summed feature 3 and summed feature 8. Strains H149T and Z2T shared diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, phosphatidylcholine and sphingoglycolipid as major polar lipids. The 16S rRNA gene sequence identity analysis indicated that strain H149T had the highest sequence identity of 98.4 % with Aurantiacibacter odishensis KCTC 23981T, and strain Z2T had that of 98.2 % with Qipengyuania pacifica NZ-96T. Phylogenetic trees based on 16S rRNA gene and core-genome sequences revealed that strains H149T and Z2T formed two independent clades in the genera Aurantiacibacter and Qipengyuania, respectively. Strain H149T had average nucleotide identity values of 74.0–81.3 % and in silico DNA–DNA hybridization values of 18.5–23.1 % with Aurantiacibacter type strains, while strain Z2T had values of 73.3–78.7 % and 14.5–33.3 % with Qipengyuania type strains. The genomic DNA G+C contents of strains H149T and Z2T were 64.3 and 61.8 %, respectively. Based on the genetic, genomic, phylogenetic, physiological and chemotaxonomic results, strains H149T (=KCTC 8397T=MCCC 1K08920T) and Z2T (=KCTC 8396T=MCCC 1K08946T) are concluded to represent two novel Erythrobacteraceae species for which the names Aurantiacibacter hainanensis sp. nov. and Qipengyuania zhejiangensis sp. nov. are proposed, respectively.