Yeosuana aromativorans gen. nov., sp nov., a mesophilic marine bacterium belonging to the family Flavobacteriaceae, isolated from estuarine sediment of the South Sea, Korea

Abstract

A marine bacterium, GW1-1(T), capable of degrading benzo[a]pyrene (BaP), was isolated from estuarine sediments of the South Sea (the Korea Strait), Korea, after an enrichment culture maintained for 2 years in a medium supplemented with a mixture of BaP and pyrene. The strain formed yellowish-brown colonies on marine agar 2216. Cells were strictly aerobic, non-motile, Gram-negative rods and produced non-diffusible carotenoid pigments. Optimal growth occurred in the presence of 1% (w/v) NaCl and at pH 7 and 33-36 degrees C. No growth occurred without supplementation with either CaCl2 or MgCl2, even in the presence of NaCl. Phylogenetic analysis based on the nearly complete sequence of the 16S rRNA gene revealed that the isolate formed a phyletic lineage with the genera Gelidibacter (93.9-94.7% gene sequence similarity), Subsaximicrobium (93.3%) and Subsaxibacter (93.9%). The isolate also showed high sequence similarities to Gaetbulibacter saemankumensis (94.5%), Algibacter lectus (94.2%), members of the genus Bizionia (93.6-94.3%) and Formosa algae (93.2%), even though it belonged to a different phyletic line. The major respiratory quinones of the isolate were menaquinones MK-5 and MK-6. The DNA G+C content was 51.4 mol%. Dominant fatty acids were i-15: 0, a-15: 0, i-15: 1 omega 10c and 16: 1. On the basis of this polyphasic taxonomic evidence, strain GW1-1(T) is classified as a member of a novel genus and species in the family Flavobacteriaceae, for which the name Yeosuana aromativorans gen. nov., sp. nov. is proposed. The type strain of the type species is GW1-1(T) (= KCCM 42019(T)=JCM 12862(T)).