Agarivorans sediminis sp. nov., an alginate-degrading bacterium isolated from sediment

A marine bacterium capable of degrading alginate, designated as strain TSD2052^T, was isolated from a tidal flat sediment sample collected in Taean County, Republic of Korea. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain TSD2052^T belonged to the genus <i>Agarivorans,</i> showing 96.2-97.8% sequence similarity. The whole genome of strain TSD2052^T was 4.62 Mb, with a DNA G+C content of 44.3 mol%. The average nucleotide identity, average amino acid identity and digital DNA-DNA hybridization values between strain TSD2052^T and all genome-sequenced species of the genus <i>Agarivorans</i> were below 76.7%, 81.7% and 20.6%, respectively, indicating values lower than the standard cut-off for species delineation. Growth was observed at 10-35 °C (optimum 25 °C), pH 6-10 (optimum pH 8) and 1-5% (w/v) NaCl (optimum 3%). The major fatty acids (>10%) were C_12:0, C_16:0, summed feature 3 (C_{16 : 1} <i>ω</i>6<i>c</i> and/or C_{16 : 1}ω<i>7c</i>) and summed feature 8 (C_{18 : 1} <i>ω</i>6<i>c</i> and/or C_18:1ω<i>7c</i>). The respiratory quinone was ubiquinone-8. The major polar lipids were phosphatidylethanolamine, phosphatidylglycerol, an unidentified aminolipid and four unidentified lipids. Based on the results of phenotypic characterization, phylogenetic analysis and genome-based comparisons, strain TSD2052^T represents a novel species in the genus <i>Agarivorans</i>, for which we propose the name <i>Agarivorans sediminis</i> sp. nov. (=KCTC 92288^T=JCM 35392^T).