Complete genome sequence of a novel Pseudomonas sp. GW-45 isolated from Antarctic Ardley cove showing DMSP...

Pseudomonas species are ubiquitous and have been frequently detected in Arctic and Antarctic environments. They participate in the biogeochemical cycling of carbon, nitrogen, and sulfur in local habitats. Pseudomonas sp. GW-45 was isolated from seawater in Ardley Cove, King George Island, Antarctica. The strain was capable of growing with dimethylsulfoniopropionate (DMSP) as the sole carbon source and producing dimethyl sulfide (DMS). The strain contained a 4,025,523 bp chromosome (G + C content of 55.71 mol%) and two plasmids with lengths of 189,931 and 2183 bp, respectively. A total of 3890 protein-coding DNA sequences, 50 tRNA genes, nine rRNA genes, and one tmRNA gene were identified. Genome-based relatedness analysis revealed that strain GW-45 represented a novel species within the genus Pseudomonas. It harbored genes involved in DMSP biosynthesis (e.g., dsyB) and catabolism (e.g., dmdA and dddP), as well as genes related to nitrate reduction (e.g., glnA, nasA, nirB, nirS, and nosZ). Three types of mobile genetic elements including insertion sequence, genomic island, and prophage were detected in the genome. These findings contribute to an improved understanding of the ecological role and adaptive evolution of Pseudomonas species in the Antarctic coastal marine environment.