Algoriphagus aestuarii sp. nov., a member of the Cyclobacteriaceae isolated from a tidal-flat sediment of the Yellow Sea in Korea

Abstract

A Gram-strain-negative, coccoid or oval-shaped, non-motile bacterial strain, designated MDM- 1T, was isolated from a tidal-flat sediment on the Korean peninsula. Strain MDM-1T was found to grow optimally at pH 7.0-8.0, at 30 °C and in the presence of 2-3% (w/v) NaCl. A neighbour-joining phylogenetic tree based on 16S rRNA gene sequences showed that strain MDM-1T falls within the clade comprising species of the genus Algoriphagus, clustering with the type strains of Algoriphagus halophilus, A. lutimaris, A. chungangensis and A. machipongonensis, with which it exhibited 97.2-98.5% 16S rRNA gene sequence similarity. Sequence similarities to the type strains of the other recognized species of the genus Algoriphagus were 92.8-97.6%. Strain MDM-1T was found to contain MK-7 as the predominant menaquinone and iso-C15: 0 and summed feature 3 (C16: 1ω6c and/or C16: 1ω7c) as the major fatty acids. The major polar lipids were identified as phosphatidylcholine, phosphatidylethanolamine and two unidentified lipids. The DNA G+C content of strain MDM-1T was determined to be 42.7 mol% and the mean DNA-DNA relatedness with A. halophilus KCTC 12051T, A. lutimaris S1-3T, A. chungangensis KCTC 23759T, A. machipongonensis DSM 24695T and A. ratkowskyi CIP 107452T was 19.7-5.2%. Differential phenotypic properties, together with the phylogenetic and genetic distinctiveness, revealed that strain MDM-1T is distinguishable from recognized species of the genus Algoriphagus. On the basis of the data presented, strain MDM-1T is proposed to represent a novel species of the genus Algoriphagus, for which the name Algoriphagus aestuarii sp. nov. is proposed. The type strain is MDM-1T (=KCTC 42199T=NBRC 110552T).