Ecological significance of Candidatus ARS69 and Gemmatimonadota in the Arctic glacier foreland ecosystems

In the present study, we investigated the ecological significance of phyla Candidatus ARS69 and Gemmatimonadota in the Arctic glacier foreland (GF) ecosystems through genome resolved metagenomics. We have reconstructed the first high-quality metagenome-assembled genome (MAG) belonging to Ca. ARS69 and 12 other MAGs belonging to phylum Gemmatimonadota from the three different Arctic GF samples.  We further elucidated these two groups phylogenetic lineage and their metabolic function through phylogenomic and pangenomic analysis. The study reveals the potential ecological role of Ca. ARS69 is associated with carbon fixation, denitrification, sulfite oxidation and reduction biochemical processes in the GF ecosystems. Similarly, the study demonstrates the widespread distribution of different classes of Gemmatimonadota across wide ranges of ecosystems and their metabolic functions, including in the polar region.