TY - JOUR

T1 - Abrupt permafrost thaw triggers activity of copiotrophs and microbiome predators

AU - Scheel, Maria

AU - Zervas, Athanasios

AU - Rijkers, Ruud

AU - Tveit, Alexander T.

AU - Ekelund, Flemming

AU - Campuzano Jiménez, Francisco

AU - Christensen, Torben R.

AU - Jacobsen, Carsten S.

N1 - Publisher Copyright: © The Author(s) 2023. Published by Oxford University Press on behalf of FEMS.

PY - 2023

Y1 - 2023

N2 - Permafrost soils store a substantial part of the global soil carbon and nitrogen. However, global warming causes abrupt erosion and gradual thaw, which make these stocks vulnerable to microbial decomposition into greenhouse gases. Here, we investigated the microbial response to abrupt in situ permafrost thaw. We sequenced the total RNA of a 1 m deep soil core consisting of up to 26 500-year-old permafrost material from an active abrupt erosion site. We analysed the microbial community in the active layer soil, the recently thawed, and the intact permafrost, and found maximum RNA:DNA ratios in recently thawed permafrost indicating a high microbial activity. In thawed permafrost, potentially copiotrophic Burkholderiales and Sphingobacteriales, but also microbiome predators dominated the community. Overall, both thaw-dependent and long-term soil properties significantly correlated with changes in community composition, as did microbiome predator abundance. Bacterial predators were dominated in shallower depths by Myxococcota, while protozoa, especially Cercozoa and Ciliophora, almost tripled in relative abundance in thawed layers. Our findings highlight the ecological importance of a diverse interkingdom and active microbial community highly abundant in abruptly thawing permafrost, as well as predation as potential biological control mechanism.

AB - Permafrost soils store a substantial part of the global soil carbon and nitrogen. However, global warming causes abrupt erosion and gradual thaw, which make these stocks vulnerable to microbial decomposition into greenhouse gases. Here, we investigated the microbial response to abrupt in situ permafrost thaw. We sequenced the total RNA of a 1 m deep soil core consisting of up to 26 500-year-old permafrost material from an active abrupt erosion site. We analysed the microbial community in the active layer soil, the recently thawed, and the intact permafrost, and found maximum RNA:DNA ratios in recently thawed permafrost indicating a high microbial activity. In thawed permafrost, potentially copiotrophic Burkholderiales and Sphingobacteriales, but also microbiome predators dominated the community. Overall, both thaw-dependent and long-term soil properties significantly correlated with changes in community composition, as did microbiome predator abundance. Bacterial predators were dominated in shallower depths by Myxococcota, while protozoa, especially Cercozoa and Ciliophora, almost tripled in relative abundance in thawed layers. Our findings highlight the ecological importance of a diverse interkingdom and active microbial community highly abundant in abruptly thawing permafrost, as well as predation as potential biological control mechanism.

KW - abrupt erosion

KW - copiotrophic

KW - permafrost

KW - protozoa

KW - transcriptomics

U2 - 10.1093/femsec/fiad123

DO - 10.1093/femsec/fiad123

M3 - Journal article

C2 - 37796894

AN - SCOPUS:85175269572

VL - 99

JO - F E M S Microbiology Ecology

JF - F E M S Microbiology Ecology

SN - 0168-6496

IS - 11

M1 - fiad123

ER -