Investigating Microbial Communities in Svalbard Permafrost

Global warming is progressing and arctic permafrost, one of the largest reservoirs of organic carbon on Earth, is experiencing the severe effects of this. The Svalbard permafrost undergoes changes in its physical and chemical properties upon thawing that may impact human and natural systems. Literature suggests that once permafrost is thawed, microbes will potentially be reactivated and metabolize the accessible freshly thawed carbon. This study aims to explore the diversity of microbes found in permafrost in relation to depth through metagenomics. Soil core samples were drilled from completely frozen active-layer and permafrost in Ny Ålesund, Svalbard. Eight boreholes were drilled in March of 2021 and three in March of 2022. Core depths varied from 0.34 to 4.2 m below the surface. Cores were removed from core liners and sliced into 5 cm depth intervals. DNA was extracted from core samples of each site using Qiagen DNeasy PowerSoil Pro Kit within hours of retrieval. A total of 44% of samples collected in 2021 did not yield a measurable amount of DNA, while average amount of DNA in the rest of the samples was 0.14 mg per 1 g of soil. The latter samples were sequenced on an Illumina NextSeq. Metagenomes recovered were an average of 1.5 Gb. Metagenome reads were processed with the use of the metaWRAP pipeline to trim, assemble and bin sequences. Over 40 bins were obtained and 15 of them had above 80% completeness and less than 2% contamination. Bins will be mapped back accordingly to generate MAGs which will give further insight into the diversity and function of microbes within permafrost.