https://repository.kopri.re.kr/handle/201206/11553 2026-04-15T00:47:15Z 2026-04-15T00:47:15Z Hwang, Kyuin Kim, Kyung Mo Lee, Hanbyul Cho, Ahnna Davis Christina L. Christner Brent C. Priscu John C. Kim, Ok-Sun https://repository.kopri.re.kr/handle/201206/16130 2025-10-16T07:27:25Z 2025-08-01T00:00:00Z

Title: Genetic isolation and metabolic complexity of an Antarctic subglacial microbiome Authors: Hwang, Kyuin; Kim, Kyung Mo; Lee, Hanbyul; Cho, Ahnna; Davis Christina L.; Christner Brent C.; Priscu John C.; Kim, Ok-Sun Abstract: Microbes inhabiting and evolving in aquatic ecosystems beneath polar ice sheets subsist under energy-limited conditions while in relative isolation from surface gene pools and their common ancestral populations of origin. Samples obtained from beneath West Antarctic Ice Sheet (WAIS) allowed us to examine evolutionary relationships of and identify metabolic pathways in microbial genomes recovered from the Mercer Subglacial Lake (SLM) ecosystem. We obtained 1,374 single-cell amplified genomes (SAGs) from individual bacterial and archaeal cells that were isolated from samples of SLM's water column and sediments. These genomes reveal that a diversity of microorganisms including Patescibacteria exists in SLM. Comparative analyses show that most genomes correspond to new species and taxonomic groups, with phylogenomic and functional evidence supporting their genetic isolation from marine and surface biomes. Genomic data reveal diverse metabolisms in SLM that are capable of oxidizing organic and inorganic compounds via aerobic or anaerobic respiration. Distinct metabolic guild structures are observed for the subglacial populations, where trophic shifts from organotrophy to chemolithotrophy may depend on oxygen availability. Our SAG data suggest versatile metabolic capabilities in the characterized microbial assemblage, reveal key energy-generating strategies in the subglacial aquatic ecosystem, and provide a framework to assess microbial evolution beneath WAIS.

2025-08-01T00:00:00Z Hwang, Kyuin Choe, Hanna Nasir, Arshan Kim, Kyung Mo https://repository.kopri.re.kr/handle/201206/11779 2022-03-24T07:14:52Z 2021-02-01T00:00:00Z

Title: Complete genome of Polaromonas vacuolata KCTC 22033T isolated from beneath Antarctic Sea ice Authors: Hwang, Kyuin; Choe, Hanna; Nasir, Arshan; Kim, Kyung Mo Abstract: Polaromonas vacuolata KCTC 22033T is an obligate aerobic, Gram-negative, psychrophilic and rod-shaped bacterium isolated from beneath the sea ice off the coast of the Palmer Peninsula, Anvers Islands, Antarctica. P. vacuolata is the type species of Polaromonas genus and the first example of gas vacuolate Betaproteobacteria isolated from marine habitats. Here, we report a complete genome of P. vacuolata KCTC 22033T, which consists of 3,837,686 bp (G + C content of 52.07%) with a single chromosome, 3461 protein-coding genes, 56 tRNAs and 6 rRNA operons. Genomic analysis revealed the presence of genes involved in bacterial adaptation under saline conditions, cold adaptation via the production of gas vesicles and cell adhesion proteins, and a photoheterotrophic lifestyle when challenged by starvation. Intriguingly, several of these genes were likely acquired from species outside the Polaromonas genus. The genomic information therefore describes the unique evolution and adaptation of P. vacuolata to its extraordinary habitat, i.e., beneath the Antarctic sea ice.

2021-02-01T00:00:00Z Cho, Ahnna Cho, Yong-Joon Kim, Soyeon Kim, Ok-Sun https://repository.kopri.re.kr/handle/201206/11970 2022-03-24T07:14:50Z 2020-05-01T00:00:00Z

Title: Draft Genome Sequence of the Psychrotolerant Bacterium Methylobacterium sp. Strain BTF04, Isolated from Freshwater in Antarctica Authors: Cho, Ahnna; Cho, Yong-Joon; Kim, Soyeon; Kim, Ok-Sun Abstract: Methylobacterium sp. BTF04, a pink-pigmented psychrotolerant bacterium, was isolated from freshwater on Barton Peninsula of King George Island, Antarctica. Here, we report the assembled draft genome sequence of Methylobacterium sp. BTF04.

2020-05-01T00:00:00Z