A Novel Phosphorus-Recovering Bacterium Pelagibacterium mangrovi sp. nov., Isolated from Mangrove Sediment.

An aerobic phosphorus-recovering strain, designated WS-203, was isolated from mangrove sediment. Strain WS-203 showed the highest 16S rRNA gene sequence similarity to the type strain of Pelagibacterium lacus (98.1%). A phylogenetic tree based on 16S rRNA gene sequences indicated that strain WS-203 clustered with members of the genus Pelagibacterium. Growth of strain WS-203 was observed at 20-37 °C (optimum, 30 °C), pH 6.0-9.5 (optimum, pH 7.5) and with 0-9.0% (w/v) NaCl (optimum, 3.0%). Strain WS-203 contained Q-10 as the respiratory quinone and C ω6c/C ω7c and C ω8c cyclo as the major fatty acids. The polar lipids detected in the strain were diphosphatidylglycerol, phosphatidylglycerol, two unidentified phospholipids, two unidentified lipids and four unidentified glycolipids. The genomic DNA G + C content of strain WS-203 was 62.2%. The average nucleotide identity (ANI) and digital DNA-DNA hybridization (dDDH) values between strain WS-203 and the closely related Pelagibacterium lacus were 78.6% and 21.7%, respectively, which were lower than the cut-off value (ANI 95-96% and dDDH 70%) for prokaryotic species delineation. On the basis of these results, strain WS-203 represents a novel species of the genus Pelagibacterium, for which the name Pelagibacterium mangrovi sp. nov. is proposed. The type strain is WS-203 (= GDMCC 1.4694 = KCTC 8652).