TY - JOUR
T1 - Comparative Metagenomics of the Active Layer and Permafrost from Low-Carbon Soil in the Canadian High Arctic
AU - Wu, Xiaofen
AU - Chauhan, Archana
AU - Layton, Alice C.
AU - Lau Vetter, Maggie C.Y.
AU - Stackhouse, Brandon T.
AU - Williams, Daniel E.
AU - Whyte, Lyle
AU - Pfiffner, Susan M.
AU - Onstott, Tullis C.
AU - Vishnivetskaya, Tatiana A.
N1 - Publisher Copyright:
© 2021 American Chemical Society
PY - 2021/9/21
Y1 - 2021/9/21
N2 - Approximately 87% of the Arctic consists of low-organic carbon mineral soil, but knowledge of microbial activity in low-carbon permafrost (PF) and active layer soils remains limited. This study investigated the taxonomic composition and genetic potential of microbial communities at contrasting depths of the active layer (5, 35, and 65 cm below surface, bls) and PF (80 cm bls). We showed microbial communities in PF to be taxonomically and functionally different from those in the active layer. 16S rRNA gene sequence analysis revealed higher biodiversity in the active layer than in PF, and biodiversity decreased significantly with depth. The reconstructed 91 metagenome-assembled genomes showed that PF was dominated by heterotrophic, fermenting Bacteroidota using nitrite as their main electron acceptor. Prevalent microbes identified in the active layer belonged to bacterial taxa, gaining energy via aerobic respiration. Gene abundance in metagenomes revealed enrichment of genes encoding the plant-derived polysaccharide degradation and metabolism of nitrate and sulfate in PF, whereas genes encoding methane/ammonia oxidation, cold-shock protein, and two-component systems were generally more abundant in the active layer, particularly at 5 cm bls. The results of this study deepen our understanding of the low-carbon Arctic soil microbiome and improve prediction of the impacts of thawing PF.
AB - Approximately 87% of the Arctic consists of low-organic carbon mineral soil, but knowledge of microbial activity in low-carbon permafrost (PF) and active layer soils remains limited. This study investigated the taxonomic composition and genetic potential of microbial communities at contrasting depths of the active layer (5, 35, and 65 cm below surface, bls) and PF (80 cm bls). We showed microbial communities in PF to be taxonomically and functionally different from those in the active layer. 16S rRNA gene sequence analysis revealed higher biodiversity in the active layer than in PF, and biodiversity decreased significantly with depth. The reconstructed 91 metagenome-assembled genomes showed that PF was dominated by heterotrophic, fermenting Bacteroidota using nitrite as their main electron acceptor. Prevalent microbes identified in the active layer belonged to bacterial taxa, gaining energy via aerobic respiration. Gene abundance in metagenomes revealed enrichment of genes encoding the plant-derived polysaccharide degradation and metabolism of nitrate and sulfate in PF, whereas genes encoding methane/ammonia oxidation, cold-shock protein, and two-component systems were generally more abundant in the active layer, particularly at 5 cm bls. The results of this study deepen our understanding of the low-carbon Arctic soil microbiome and improve prediction of the impacts of thawing PF.
KW - 16S rRNA
KW - Arctic
KW - active layer
KW - metabolism
KW - metagenome-assembled genome
KW - permafrost
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U2 - 10.1021/acs.est.1c00802
DO - 10.1021/acs.est.1c00802
M3 - Article
C2 - 34472853
AN - SCOPUS:85114949636
SN - 0013-936X
VL - 55
SP - 12683
EP - 12693
JO - Environmental Science and Technology
JF - Environmental Science and Technology
IS - 18
ER -