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

Two Gram-stain-negative, rod-shaped, non-motile, aerobic and carotenoid-producing strains, belonging to the family Erythrobacteraceae, designated as H149^T and Z2^T, were isolated from tidal flat sediment samples collected in Hainan and Zhejiang, PR China, respectively. Growth of strain H149^T 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 Z2^T 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 H149^T were C_16 : 0, summed feature 3 and summed feature 8, while those of strain Z2^T were C_17 : 1  ω6c, summed feature 3 and summed feature 8. Strains H149^T and Z2^T shared diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, phosphatidylcholine and sphingoglycolipid as major polar lipids. The 16S rRNA gene sequence identity analysis indicated that strain H149^T had the highest sequence identity of 98.4 % with Aurantiacibacter odishensis KCTC 23981^T, and strain Z2^T had that of 98.2 % with Qipengyuania pacifica NZ-96^T. Phylogenetic trees based on 16S rRNA gene and core-genome sequences revealed that strains H149^T and Z2^T formed two independent clades in the genera Aurantiacibacter and Qipengyuania, respectively. Strain H149^T 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 Z2^T had values of 73.3-78.7 % and 14.5-33.3 % with Qipengyuania type strains. The genomic DNA G+C contents of strains H149^T and Z2^T were 64.3 and 61.8 %, respectively. Based on the genetic, genomic, phylogenetic, physiological and chemotaxonomic results, strains H149^T (=KCTC 8397^T=MCCC 1K08920^T) and Z2^T (=KCTC 8396^T=MCCC 1K08946^T) are concluded to represent two novel Erythrobacteraceae species for which the names Aurantiacibacter hainanensis sp. nov. and Qipengyuania zhejiangensis sp. nov. are proposed, respectively.