Donghicola mangrovi sp. nov., a member of the family Rhodobacteraceae isolated from mangrove forest in Thailand

Two novel Gram-stain-negative, rod-shaped and non-motile bacterial strains, designated B5-SW-15(T) and C2-DW-16, were isolated from water collected in mangrove forests in Ranong Province, Thailand. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strains B5-SW-15(T) and C2-DW-16 belonged to the genus Donghicola and were most closely related to Donghicola tyrosinivorans DSM 100212(T) (98.2 and 98.1%, respectively) and Donghicola eburneus DSM 29127(T) (97.7 and 97.6%, respectively). The average nucleotide identity and digital DNA-DNA hybridization values between strain B5-SW-15(T), strain C2-DW-16 and related species were 95.8 and 71.6% (to strain C2-DW-16), 76.8 and 21.3% (to D. tyrosinivorans DSM 100212(T)) and 80.3 and 24.2 % (to D. eburneus DSM 29127(T)), respectively. The predominant cellular fatty acids (>5 %) were summed feature 8 (C-18:1 omega 6c and/or C-18:1 omega 7c), C-16:0 and C-12:1 3-OH. Ubiquinone Q-10 was the sole respiratory quinone. DNA G+C contents of the isolates were 61.0 and 61.2 mol% based on whole genome sequences. Strains B5-SW-15(T) and C2-DW-16 contained aminolipid, phosphatidylcholine, phosphatidylethanolamine and phosphatidylglycerol as the major polar lipids. On the basis of the results from phenotypic, chemotaxonomic and phylogenetic analyses, strains B5-SW-15(T) and C2-DW-16 constitute a novel species of the genus Donghicola in the family Rhodobacteraceae for which the name Donghicola mangrovi sp. nov. is proposed. The type strain is B5-SW-15(T) (=BCC 56522(T)=TBRC 9562(T)=KCTC 72743(T)).