Abstract
An endophytic, Gram-staining-negative bacterium was isolated from sterilized roots of a plant, Suaeda maritima, growing on tidal flats. Cells of the strain were motile by means of a single polar flagellum and colonies were pigmented light brown. Strain YC6927(T) was able to grow at 15-37 °C (optimum at 28-30 °C) and at pH 5.0-10.0 (optimum at pH 7.0-8.0). The strain was able to grow at NaCl concentrations of 0-9.0 % (w/v), with optimum growth at 0-5.0 % NaCl. Comparison of 16S rRNA gene sequences showed that the strain was a member of the genus Labrenzia, exhibiting the highest similarity to Labrenzia marina mano18(T) (97.6 % sequence similarity). Strain YC6927(T) produced light-brown carotenoid pigments. The major respiratory quinone was Q-10 and the DNA G+C content was 58.5 mol%. The DNA-DNA relatedness between strain YC6927(T) and closely related strains was between 8.2±1.8 and 20.3±1.5 %. Strain YC6927(T) contained summed feature 8 (C18 : 1ω7c and/or C18 : 1ω6c) and C14 : 0 3-OH as major fatty acids, confirming the affiliation of the strain with the genus Labrenzia. The polar lipids consisted of phosphatidylglycerol, diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylcholine, phosphatidylmonomethylethanolamine, an unknown aminolipid, an unknown phospholipid and five unknown lipids. On the basis of phylogenetic analysis, physiological and biochemical characterization and DNA-DNA hybridization data, strain YC6927(T) should be assigned to a novel species of the genus Labrenzia, for which the name Labrenzia suaedae sp. nov. is proposed. The type strain is YC6927(T) ( = KACC 13772(T) = DSM 22153(T)). An emended description of the genus Labrenzia is also proposed.