Marinomonas epiphytica sp nov., isolated from a marine intertidal macroalga

A novel Gram-stain-negative, aerobic marine bacterial strain, SAB-3(T), was isolated from brown macroalgae (Dictyota sp.) growing in the Arabian sea, Goa, India. The strain grew optimally at 30 degrees C, with 2.0-4.0% (w/v) NaCl and at pH 7.0 on marine agar medium. Strain SAB-3T was unable to hydrolyse aesculin and did not grow in the presence of rifamycin but showed resistance to antibiotics such as cefadroxil and co-trimoxazole. The major fatty acids were summed feature 8 (C-18 : 1 omega 7c/C-18 : (1)omega 6c), summed feature 3 (C-16 : 1 omega 7c/C-16 : 1 omega 6c) and C-16 : 0, and Q-8 was the major ubiquinone. The major polar lipids were phosphatidylglycerol and phosphatidylethanolamine. The DNA G+C content was 41.0 mol%. 16S rRNA gene sequencing and phylogenetic analysis indicated that the strain was a member of the genus Marinomonas with Marinomonas aquiplantarum IVIA-Po-159(T) (97.6% similarity), Marinomonas posidonica IVIA-Po-181(T) (97.5 %) and Marinomonas dokdonensis DSM 17202(T) (97.4 %) as the closest relatives. Whole genome relatedness determined through DNA-DNA hybridization revealed values of 40-50% (below the 70% threshold recommended for species delineation) with the above three species, thus confirming it as representing a distinct and novel species of the genus Marinomonas for which the name Marinomonas epiphytica sp. nov. is proposed. The type strain is SAB-3(T) (= JCM 31365(T) = KCTC 52293(T) = MTCC 12569(T)).