A Gram-negative, rod-shaped and motile bacterium, designated strain J95T, was isolated from the rhizosphere soil of a mangrove plant Kandeliacandel (L.) Druce in Mai Po Nature Reserve, Hong Kong. Growth of strain J95T was observed at pH 5.0-8.5 (optimum, 6.0-7.0), between 10-40 °C (30-37 °C) and in the presence of 0-9 % (w/v) NaCl (0.5-3 %). Chemotaxonomic analysis showed ubiquinone-10 as the predominant respiratory quinone and C18 : 1ω7c and C19 : 0 cycloω8c as the major fatty acids. The major polar lipids were lipid, aminolipid, phospholipid, phosphatidylcholine, phosphatidylglycerol and phosphatidylethanolamine. The genomic contained a circular chromosome of 5.48 Mb with a DNA G+C content of 65.7 mol%. The genome included 5299 genes. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain J95T belongs to the genus Ruegeria with highest sequence similarity (96.8 %) to the type strain Ruegeria marina ZH17T. The combined phenotypic, chemotaxonomic and phylogenetic data suggested that strain J95T represents a novel species of the genus Ruegeria, for which the name Ruegeria kandeliae sp. nov. is proposed. The type strain is J95T (=MCCC 1K03284T=DSM 104293T).
Keywords: Kandelia candel; Ruegeria kandeliae; rhizosphere soil.