Luteimonas padinae sp nov., an epiphytic bacterium isolated from an intertidal macroalga

A Gram-stain-negative, rod-shaped bacterium, forming yellow colonies and designated CDR SL 15(T), was isotated from the surface of Padina sp., a brown macroalga, which grows in the Western coastal regions of the state of Goa, India. The 16S rRNA gene sequence phylogeny placed the strain in the genus Luteimonas and it showed closest sequence similarity to Luteimonas terricola BZ92r(T) (97.6%) and <97.0% to other species of the genus Luteimonas. Chemotaxonomic features, such as having iso-C-15:0 and summed feature 9 (C-16:0 10-methyl/ iso-C-17:1 omega 9c) as the major fatty acids and 0-8 as the only ubiquinone further supported its placement within this genus. There were some critical differences in phenotypic properties between Luteimonas padinae sp. nov. CDR SL 15(T) and L. terricola DSM 22344(T) i.e. temperature range for growth and salinity range and optimum for growth (L. terricola is a psychrotolerant bacterium with a lower optimum temperature for growth), acid production and assimilation of substrates, enzyme activities and resistance to certain antibiotics. The DNA DNA relatedness value of the novel strain with its closest phylogenetic relative was only 40%, below the 70% threshold value recommended for species delineation. All these characteristics are consistent with strain CDR SL 15(T) representing a novel species of the genus Luteimonas, for which the name Luteimonas padinae sp. nov. is proposed. The type strain is CDR SL 15(T) (=DSM 101536(T)=KCTC 52403(T)).