Cold adaptation and response genes of Antarctic Cryobacterium sp. SO2 from the Fildes Peninsula, King George Island

Abstract

Cryobacterium spp. are Gram-positive bacteria that inhabit diverse geographical locations, particularly extremely cold environments like the Polar Regions. However, strategies that enable them to survive in harsh Antarctic environments are not fully understood. In this study, we conducted a comparative genomic analysis of the Antarctic Cryobacterium sp. SO2 as well as other members of the Cryobacterium genus. Phylogenetic analysis revealed that strain SO2 formed a distinct cluster with the validly described species: C. adonitolivorans, C. actose, C. soli, C. arcticum, and C. zongtaii. Comparative analysis based on ANI and AAI indicated that strain SO2 is a novel species. Relative Synonymous Codon Usage (RSCU) of Cryobacterium species exhibits a bias towards codon ending with G/C. The genomes of all strains harbored numerous genes associated with environmental-associated stress responses, including oxidative stress response, general stress response, heat-stress response, cold-stress response, cell envelope alteration, and osmotic stress response. Strain SO2 and related strains possess genes involved in breaking down and utilization of both plant and animal carbohydrate-containing materials. KEGG annotation indicated that strain SO2 and related species shared almost the same genes for the metabolism of trehalose (TreS, partial TPS/TPP, and TreY-TreZ pathway) and glycogen (classical and non-classical pathway). The results from this work helped us to better understand the genomic characteristics of Cryobacterium spp. in terms of genomic diversity and adaptation strategies, which may have significant implications for biotechnology and climate change research.