Metagenomics reveals global-scale contrasts in nitrogen cycling and cyanobacterial light-harvesting mechanisms in glacier cryoconite

作者：Takumi Murakami, Nozomu Takeuchi, Hiroshi Mori, Yuu Hirose, Arwyn Edwards, Tristram D. L. Irvine-Fynn, Zhongqin Li, Satoshi Ishii, Takahiro Segawa · 发表于：Microbiome · 年份：2022 · DOI：10.1186/s40168-022-01238-7 · 被引用次数：42 · 研究领域：Polar Research and Ecology、Photosynthetic Processes and Mechanisms、Cryospheric studies and observations

BACKGROUND: Cryoconite granules are mineral-microbial aggregates found on glacier surfaces worldwide and are hotspots of biogeochemical reactions in glacier ecosystems. However, despite their importance within glacier ecosystems, the geographical diversity of taxonomic assemblages and metabolic potential of cryoconite communities around the globe remain unclear. In particular, the genomic content of cryoconite communities on Asia's high mountain glaciers, which represent a substantial portion of Earth's ice masses, has rarely been reported. Therefore, in this study, to elucidate the taxonomic and ecological diversities of cryoconite bacterial consortia on a global scale, we conducted shotgun metagenomic sequencing of cryoconite acquired from a range of geographical areas comprising Polar (Arctic and Antarctic) and Asian alpine regions. RESULTS: Our metagenomic data indicate that compositions of both bacterial taxa and functional genes are particularly distinctive for Asian cryoconite. Read abundance of the genes responsible for denitrification was significantly more abundant in Asian cryoconite than the Polar cryoconite, implying that denitrification is more enhanced in Asian glaciers. The taxonomic composition of Cyanobacteria, the key primary producers in cryoconite communities, also differs between the Polar and Asian samples. Analyses on the metagenome-assembled genomes and fluorescence emission spectra reveal that Asian cryoconite is dominated by multiple cyanobacterial ...