Agarivorans aestuarii sp. nov., an agar-degrading bacterium isolated from a tidal flat.

Abstract

A Gram-reaction-negative, aerobic, non-spore forming, rod-shaped bacterium motile with a single polar flagellum, designated strain hydD622T, was isolated from the sediment of a tidal flat at Asan Bay, Korea. Strain hydD622T exhibited an agarolytic activity. Comparison of 16S rRNA gene sequences revealed that strain hydD622T was closely related to Agarivorans litoreus KCTC 42116T, Agarivorans albus KCTC 22256T and Agarivorans gilvus KCTC 32555T with similarities of 98.4, 98.0 and 96.5 %, respectively. Strain hydD622T was clustered distantly from the other genera in the family Alteromonadaceae but formed a unique clade within the genus Agarivorans based on the 16S rRNA gene sequence. The DNA-DNA relatedness with Agarivorans litoreus KCTC 42116T and Agarivorans. albus KCTC 22256T was 39.0 and 37.8 %, respectively. The major fatty acids (>10 %) were C16 : 0,C16 : 1ω6c/C16 : 1ω7c and C18 : 1ω6c/C18 : 1ω7c. The respiratory quinone was ubiquinone-8, and the polar lipid profile consisted of phosphatidylethanolamine, diphosphatidylglycerol, phosphatidylglycerol and an unidentified lipid. The DNA G+C content was 44 mol%. On the basis of physiological, chemotaxonomic and phylogenetic analyses, strain hydD622T represents a novel species within the genus Agarivorans, for which the name Agarivorans aestuarii sp. nov. is proposed. The type strain of Agarivorans aestuarii sp. nov. is hydD622T (=KCTC 32543T=CGMCC 1.12692T).