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

Abstract

This study describes a Gram-stain-negative, rod-shaped, facultatively anaerobic bacterial species isolated from the octocoral Litophyton 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 Endozoicomonas 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 Endozoicomonas genus, based on comparisons with the designated novel type strain NE40^T. The closest 16S rRNA gene relatives to strain NE40^T are Endozoicomonas montiporae CL-33^T (98.2%), Endozoicomonas euniceicola EF212^T (97.6%) and Endozoicomonas gorgoniicola 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 Endozoicomonas 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 Endozoicomonas 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 ω6c and/or C_16 : 1 ω7c), summed feature 8 (C_18 : 1 ω6c and/or C_18 : 1 ω7c), C_16 :0 and C_14 :0. Strain NE40^T presents oxidase, catalase and β-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 Endozoicomonas lisbonensis sp. nov. (type strain NE40^T=DSM 118084^T=UCCCB 212^T).