Genomic and taxonomic characterization of the Comamonas sp. nov., a bacterium isolated from Brazilian Cerrado soil.

Abstract

A novel strain identified as Comamonas sp. was isolated from the soil of the Brazilian savanna-like Cerrado biome, a global hotspot for biodiversity. Phylogenetic analysis based on 16 S rRNA gene sequences showed that this strain is classified as Betaproteobacteria from the family Comamonadaceae. The digital DNA-DNA hybridization (dDDH) and Average Nucleotide Identity (ANI) results, of respectively 48.6% and < 93%, indicated that Comamonas sp. consists in a new species with Comamonas testosteroni as its closest strain. Comamonas sp. is a Gram-negative, rod-shaped, and non-spore-forming bacterium. Its colonies typically exhibit a round, convex, and irregular shape with a clear color and spotted edges. It is characterized as non-fermenting, aerobic, and motile, presenting both oxidase and catalase activities. The optimal growth parameters for this bacterial strain are 30 °C, a pH range of 5-8, and 0% NaCl. In addition, its fatty acid profile included palmitic acid (C_16:0) at 26.94%, 13-Methyltetradecanoic Acid (iso-C_15:0) at 10.94%, myristic acid (C_14:0) at 8.94%, and a summed feature comprising 16:1 ω7c, 16:1 ω6c, or 16:1 at 15.8%. Genomic analysis of Comamonas sp. revealed a GC content of 62.1% across its 5.6 Mb genome. Phylogenomic and pangenome analyses, along with in silico phenotypic characterization indicate that this strain represents a novel species within the Comamonas genus, which we propose to name Comamonas brasiliensis nov.