Comamonas halotolerans sp. nov., isolated from the faecal sample of a zoo animal, Naemorhedus caudatus.

Abstract

Strain NoAH^T (=KACC 23135^T=JCM 35999^T), a novel Gram-negative, motile bacterium with a rod-shaped morphology, was isolated from the zoo animal faecal samples, specifically the long-tailed goral species Naemorhedus caudatus. The novel bacterial strain grew optimally in a nutrient broth medium under the following conditions: 1-2% (w/v) NaCl, pH 7-8 and 30 °C. The strain NoAH^T exhibited high tolerance to NaCl, with the ability to tolerate up to 7% (w/v) NaCl. Based on phylogenetic analyses using 16S rRNA gene sequencing, strain NoAH^T was found to have the closest relatedness to Comamonas jiangduensis YW1^T (98.5%), Comamonas aquatica ATCC 11330^T (97.9%), Comamonas resistens KCTC 82561^T (97.9%), Comamonas fluminis CJ34^T (97.7%) and Comamonas suwonensis EJ-4^T (97.6%). The genome size and genomic DNA G+C content of strain NoAH^T were 4.05 Mbp and 55.9 mol%, respectively. A whole-genome-level comparison of strain NoAH^T with C. jiangduensis YW^T, Comamonas kerstersii LMG 3475^T, C. aquatica NBRC 14918^T, Comamonas terrigena NBRC 12685^T and C. fluminis CJ34^T revealed the following orthologous average nucleotide identity values: 80.1, 79.0, 78.6, 76.3 and 75.2%, respectively. The major polar lipids of strain NoAH^T were phosphatidylethanolamine, phosphatidylglycerol and diphosphatidylglycerol. Considering our findings in chemotaxonomic, genotypic and phenotypic characteristics, strain NoAH^T is identified as a novel species within the genus Comamonas, for which the name Comamonas halotolerans sp. nov. is proposed.