Flavivirga spongiicola sp. nov. and Flavivirga abyssicola sp. nov., Isolated from Marine Environments.

Abstract

Two novel Gram-stain-negative, strictly-aerobic, rod-shaped (1.2 ± 3.4 μm × 0.3 ± 0.7 μm), and non-motile marine bacterial species, designated MEBiC05379^T and MEBiC07777^T, were isolated from a marine sponge Pseudaxinella sp. in Gangneung City and deep-sea sediments of the Ulleung basin in the East Sea of Korea, respectively. The 16S rRNA gene sequence analysis revealed high levels of similarities between these strains and members of the genus Flavivirga (97.0-98.4% sequence identities). Both novel strains revealed as mesophilic, neutrophilic in pH and slightly halophilic. Similar to those of other Flavivirga members, the primary cellular fatty acids of both strains were iso-C_15:0, iso-C_15:1 G, iso-C_15:03-OH, and iso-C_17:0 3-OH, with MEBiC05379^T and MEBiC07777^T containing relatively higher proportions of C_12:0 and summed feature 3 (C_16:1ω7c and/or C_16:1ω6c). In both taxa, the major isoprenoid quinone was MK-6. The DNA G + C contents of MEBiC05379^T and MEBiC07777^T genomes were 32.62 and 32.46 mol%, respectively. Compared to other members of Flavivirga, both strains exhibited similar DNA G + C ratio and fatty acids pattern, yet enzyme expression and carbon sources utilization pattern were different. Genomes of the genus Flavivirga showed enzyme preferences to fucoidan and sulfated galactans. Considering the monophyly rule, AAI values delineate the genus Flavivirga from adjacent genera calculated to be 76.0-78.7%. Based on the phenotypic, genomic and biochemical data, strains for MEBiC05379^T and MEBiC07777^T thus represent two novel species in the genus Flavivirga, for which the names Flavivirga spongiicola sp. nov. (MEBiC05379^T [= KCTC 92527 ^T = JCM 16662 ^T]), and Flavivirga abyssicola sp. nov. (MEBiC07777^T [= KCTC 92563 ^T = JCM 36477 ^T]) are proposed.