Flavobacterium aestuarii sp. nov., a novel species isolated from the Pearl River Estuary

Strain SYSU M80003^T, a Gram-stain-negative and aerobic bacterium, was isolated from water sample of the Pearl River Estuary, Guangzhou, Guangdong, PR China. The strain could grow at 4-37 °C (optimal: 28 °C), pH 6.0-8.0 (optimal: 7.0), and with 0-1% NaCl (w/v, optimal: 0%). The main fatty acids were anteiso-C_14:0, Summed Feature 3 (C_16:1 ω7c and/or C_16:1 ω6c) and iso-C_15:0. The predominant respiratory quinone was MK-6. The polar lipids contained phosphatidylethanolamine, three unidentified aminolipids, two unidentified aminophospholipids, and two unidentified polar lipids. The genomic DNA G + C content was 35.06%. Phylogenetic analysis based on the 16S rRNA gene revealed that strain SYSU M80003^T was closely related to Flavobacterium aquicola JCM 30987 ^T with similarity of 97.28%. Furthermore, the average nucleotide identity (ANI) and digital DNA-DNA hybridization (dDDH) values between strain SYSU M80003^T and F. aquicola JCM 30987^T were 83.8% and 28.1%, respectively. Based upon the consensus of phylogenetic and ANI analyses, we conclude that strain SYSU M80003^T represents a novel species within the genus Flavobacterium, for which the name Flavobacterium aestuarii sp. nov. is proposed. The type strain is SYSU M80003^T (= GDMCC 1.4521^T = KCTC 102267^T).