Sulfitobacter delicatus sp. nov. and Sulfitobacter dubius sp. nov., respectively from a starfish (Stellaster equestris) and sea grass (Zostera marina)

On the basis of data from phenotypic and genotypic characterization and analysis of 16S rRNA gene sequences, two novel species belonging to the genus Sulfitobacter are described. Strains KMM 3584(T), a pale-yellowish, non-motile strain isolated from a starfish (Stellaster equestris), and KMM 3554(T), which is motile by means of a single subpolar flagellum and was isolated from sea grass (Zostera marina), are marine, Gram-negative, aerobic, rod-shaped organisms. Both strains have the ability to degrade gelatin, but not casein, chitin, agar, DNA, Tween 80 or starch. Strain KMM 3584(T) decomposed alginate and grew at NaCl concentrations of 1-8 % and temperatures of 12-37 degrees C, whereas strain KMM 3554(T) grew in 1-12 % NaCl and at temperatures of 10-30 degrees C. The predominant fatty acid was 18 : 1omega7, amounting to up to 80 % of the total fatty acids. The other characteristic feature was the presence of 18 : 2 isomers. The DNA G+C contents of KMM 3584(T) and KMM 3554(T) were respectively 60.0 and 63.7 mol%. The level of DNA similarity between the two strains was 33 %. DNA from KMM 3584(T) and KMM 3554(T) had hybridization values of 5-24 % and 10-41 %, respectively, with DNA from the type strains of Sulfitobacter pontiacus, Sulfitobacter brevis, Sulfitobacter mediterraneus and Staleya guttiformis. It is proposed that strains KMM 3584(T) (=LMG 20554(T)=ATCC BAA-321(T)) and KMM 3554(T) (=LMG 20555(T)=ATCC BAA-320(T)) represent two novel species, Sulfitobacter delicatus sp. nov. and Sulfitobacter dubius sp. nov., respectively.