Hoeflea suaedae sp nov., an endophytic bacterium isolated from the root of the halophyte Suaeda maritima

Abstract

A Gram-negative, aerobic, short rod-shaped bacterium, designated strain YC6898(T), was isolated from the surface-sterilized root of a halophyte (Suaeda maritime) inhabiting tidal flat of Namhae Island, Korea. Strain YC6898(T) grew optimally at 30-37 degrees C and pH 6.5-7.5. The strain inhibited mycelial growth of Pythium ultimum and Phytophthora capsici. Phylogenetic analyses based on 16S rRNA gene sequences indicated that strain YC6898(T) belongs to the genus Hoe flea in the family Phyllobacteriaceae. Its closest relatives were Hoeflea alexandrii AM1V30(T) (96.7% 16S rRNA gene sequence similarity), Hoeflea anabaenae WH2K(T) (95.7%), Hoeflea phototrophica DFL-43(T) (95.5%) and Hoe flea marina LMG 128(T) (94.8 %). Strain YC6898(T) contained Q-10 as the major ubiquinone. The major fatty acids of strain YC6898(T) were C-18:1 omega 7C (61.1%), C-16:0 (11.9%), 11-methyl C-18:1 omega 7c (9.6 %) and C-19:0 cyclo omega 8c (8.0%). The polar lipids were phosphatidylcholine, phosphatidylethanolamine, phosphatidylmonomethylethanolamine, phosphatidylglycerol, unknown lipids and an unknown glycolipid. The total genomic DNA G+C content was 53.7 mol%. On the basis of phenotypic, chemotaxonomic and phylogenetic analysis, strain YC6898(T) represents a novel species of the genus Hoe flea, for which the name Hoe flea suaedae sp. nov. is proposed. The type strain is YC6898(T) (=KACC 14911(T)=NBRC 107700(T)).