Seonamhaeicola algicola sp. nov., a complex-polysaccharide-degrading bacterium isolated from Gracilaria blodgettii, and emended description of the genus Seonamhaeicola.

Abstract

A novel Gram-stain-negative, yellow, rod-shaped, facultatively anaerobic, gliding bacterial strain, designated Gy8T, was isolated from the surface of Gracilaria blodgettii. This bacterium was able to degrade various polysaccharides, especially agar and alginate. The major cellular fatty acids (>10 % of the total fatty acids) were C15 : 0, iso-C15 : 0, C15 : 0 3-OH and iso-C15 : 1. The major menaquinone was MK-6. The DNA G+C content was 35.3 mol%. The major polar lipids consisted of phosphatidylethanolamine and two unknown polar lipids. Strain Gy8T showed highest 16S rRNA gene sequence similarity to Seonamhaeicola aphaedonensis AH-M5T (95.6 %), and these two strains formed a distinct branch in phylogenetic trees generated with the neighbour-joining, maximum-likelihood and maximum-parsimony algorithms. The novel strain and the reference type strain of the single species described to date in the genus Seonamhaeicola contained MK-6 as the major menaquinone, iso-C15 : 0 and iso-C15 : 1 as the major fatty acids, and phosphatidylethanolamine and an unknown lipid as the major polar lipids. Based on phenotypic, chemotaxonomic and phylogenetic analysis, strain Gy8T is considered to represent a novel species within the genus Seonamhaeicola in the family Flavobacteriaceae, phylum Bacteroidetes, for which the name Seonamhaeicola algicola sp. nov. is proposed. The type strain is Gy8T ( = KCTC 42396T = CICC 23816T).