Marinomonas algicola sp. nov. and Marinomonas colpomeniae sp. nov., isolated from marine macroalgae

Two Gram-stain-negative, aerobic, rod-shaped bacteria, polar flagellated, designated strains SM2066T and SM1966T, were respectively isolated from the surfaces of Colpomenia sinuosa and Ulva pertusa macroalgae collected off the coastal areas of Rongcheng, PR China. Strain SM2066(T) grew at 8?37 degrees C and with 0.5?7.0 % (w/v) NaCl, while strain SM1966(T) grew at 5?30 degrees C and with 0.5?8.5% (w/v) NaCl. Both of them reduced nitrate to nitrite and required Na+ for growth but neither of them hydrolysed starch and DNA. Phylogenetic analysis based on 16S rRNA gene and single -copy orthologous cluster sequences revealed that both strains SM2066T and SM1966(T) were affiliated with the genus Marinomonas but formed distinct phylogenetic branches from known Marinomonas species, respectively sharing the highest 16S rRNA gene sequence similarities with type strains of Marinomonas ushuaiensis (97.9 %) and Marinomonas blandensis (96.7 %). The digital DNA-DNA hybridization and average nucleotide identity values between strains SM2066T and SM1966T and type strains of closely related Marinomonas species were all below 22.9 and 79.9 mol%, respectively. The major fatty acids of the two strains were summed feature 3 (C16:1 ?6c/C16:1 ?7c), summed feature 8 (C18:1 omega 7c) and C16:0, with their predominant polar lipids being phosphatidylethanolamine and phosphatidylglycerol, and their sole respiratory quinone being Q-8. The genomic DNA G+C contents of strains SM2066(T) and SM1966(T) determined from genomic sequences were 40.3 and 41.6 mol%, respectively. On the basis of the polyphasic evidence presented in this study, strains SM2066(T) and SM1966(T) are considered to represent two novel species within the genus Marinomonas, for which the names Marinomonas colpomeniae sp. nov. and Marinomonas algicola sp. nov. are proposed. The type strains are SM2066(T) (=MCCC 1K04390(T)= KCTC 82372(T)) and SM1966T (=MCCC 1K04387(T)= KCTC 72848(T)), respectively.