Alteromonas flava sp. nov. and Alteromonas facilis sp. nov., two novel copper tolerating bacteria isolated from a sea cucumber culture pond in China.

Two bacterial strains, P0211 and P0213, were isolated from a sea cucumber culture pond in China. The strains were able to resist high copper levels. These two strains were characterized at the phenotypic, chemotaxonomic, and genomic level. They were completely different colors, but the 16S rRNA genes showed 99.30% similarity. Phylogenetic analysis based on the sequences of the 16S rRNA gene and five housekeeping genes (dnaK, sucC, rpoB, gyrB, and rpoD) supported the inclusion of these strains within the genus Alteromonas, and the two isolated strains formed a group separated from the closest species Alteromonas aestuariivivens KCTC 52655. Genomic analyses, including average nucleotide identity (ANIb and ANIm), DNA-DNA hybridization (DDH), and the percentage of conserved proteins (POCP), clearly separated strains P0211 and P0213 from the other species within the genus Alteromonas with values below the thresholds for species delineation. The chemotaxonomic features (including fatty acid and polar lipid analysis) of strains P0211 and P0213 also confirmed their differentiation from the related taxa. The results demonstrated that strains P0211 and P0213 represented two novel species in the genus Alteromonas, for which we propose the names Alteromonas flava sp. nov., type strain P0211 (=KCTC 62078=MCCC 1H00242), and Alteromonas facilis sp. nov., type strain P0213 (=KCTC 62079=MCCC 1H00243).