Uncovering the Fresh Snowfall Microbiome and Its Chemical Characteristics with Backward Trajectories in Daejeon, the Republic of Korea

Snow covers a large surface area of the Earth and provides a surface for the exchange of biological and chemical components. However, the microbial composition and chemical components of snow are poorly understood. We assessed the bacterial and fungal diversity and chemical characteristics in freshly deposited snowfall samples collected from a sub-urban site in Daejeon, the Republic of Korea. We analyzed the snow samples using DNA amplification followed by Illumina MiSeq Sequencing for the microbiome, ion chromatography for the cations (Na+, Ca2+, Mg2+, and NH4+) and anions (SO42−, NO3−, and Cl−), and a water-soluble organic carbon (WSOC) and water-soluble nitrogen (WSTN) analyzer for WSOC and WSTN. NO3−, Actinobacteria (bacteria), and Ascomycota (fungi) were the most abundant components in the fresh snowfall samples. The air mass backward trajectories arrived mostly at this site from the northwest direction during this study period, which included the regions belonging to Russia, China, Mongolia, the Gobi Desert, the Yellow Sea, and South Korea. Principal component analysis suggested that the snow components were associated with sources belonging to secondary chemical compounds, dust, and sea salt during the study period.