Endozoicomonas lisbonensis sp. nov., a novel marine bacterium isolated from the soft coral Litophyton sp. at Oceanário de Lisboa in Portugal

This study describes a Gram-stain-negative, rod-shaped, facultatively anaerobic bacterial species isolated from the octocoral <i>Litophyton</i> sp. inhabiting the live coral aquarium at Oceanário de Lisboa in Portugal. Four strains, NE35, NE40^T, NE41 and NE43, were classified into the genus <i>Endozoicomonas</i> by means of 16S rRNA gene and whole-genome sequence homologies. We then performed phylogenetic, phylogenomic and biochemical analyses to examine their novel species status within the <i>Endozoicomonas</i> genus, based on comparisons with the designated novel type strain NE40^T. The closest 16S rRNA gene relatives to strain NE40^T are <i>Endozoicomonas montiporae</i> CL-33^T (98.2%), <i>Endozoicomonas euniceicola</i> EF212^T (97.6%) and <i>Endozoicomonas gorgoniicola</i> PS125^T (97.2%). The four strains show genome-wide average nucleotide identity scores above the species level cut-off (95%) with one another and below the cut-off with all <i>Endozoicomonas</i> type strains with publicly available genomes. Digital DNA-DNA hybridization further supported the classification of the strains as a novel species, showing values below 70% when compared with other <i>Endozoicomonas</i> type strains. The DNA G+C content of NE40^T was 49.0 mol%, and its genome size was 5.45 Mb. Strain NE40^T grows from 15 to 37 °C, with 1-5% (w/v) NaCl, and between pH 6.0 and 8.0 in marine broth and shows optimal growth at 28-32 °C, 2-3% NaCl and pH 7.0-8.0. The predominant cellular fatty acids are summed feature 3 (C_{16 : 1} ω6<i>c</i> and/or C_{16 : 1} ω7<i>c</i>), summed feature 8 (C_{18 : 1} ω6<i>c</i> and/or C_{18 : 1} ω7<i>c</i>), C_{16 :0} and C_{14 :0}. Strain NE40^T presents oxidase, catalase and <i>β</i>-galactosidase activities and can reduce nitrates to nitrites and degrade cellulose, chitin, agarose and xylan. Based on the polyphasic approach employed in this study, we propose the novel species name <i>Endozoicomonas lisbonensis</i> sp. nov. (type strain NE40^T=DSM 118084^T=UCCCB 212^T).