TY - JOUR

T1 - Bacterial and protozoan dynamics upon thawing and freezing of an active layer permafrost soil

AU - Schostag, Morten

AU - Priemé, Anders

AU - Jacquiod, Samuel

AU - Russel, Jakob

AU - Ekelund, Flemming

AU - Jacobsen, Carsten Suhr

N1 - CENPERM[2019]

PY - 2019

Y1 - 2019

N2 - The active layer of soil overlaying permafrost in the Arctic is subjected to annual changes in temperature and soil chemistry, which we hypothesize to affect the overall soil microbial community. We investigated changes in soil microorganisms at different temperatures during warming and freezing of the active layer soil from Svalbard, Norway. Soil community data were obtained by direct shotgun sequencing of total extracted RNA. No changes in soil microbial communities were detected when warming from −10 to −2 °C or when freezing from −2 to −10 °C. In contrast, within a few days we observed changes when warming from −2 to +2 °C with a decrease in fungal rRNA and an increase in several OTUs belonging to Gemmatimonadetes, Bacteroidetes and Betaproteobacteria. Even more substantial changes occurred when incubating at 2 °C for 16 days, with declines in total fungal potential activity and decreases in oligotrophic members from Actinobacteria and Acidobacteria. Additionally, we detected an increase in transcriptome sequences of bacterial phyla Bacteriodetes, Firmicutes, Betaproteobacteria and Gammaproteobacteria—collectively presumed to be copiotrophic. Furthermore, we detected an increase in putative bacterivorous heterotrophic flagellates, likely due to predation upon the bacterial community via grazing. Although this grazing activity may explain relatively large changes in the bacterial community composition, no changes in total 16S rRNA gene copy number were observed and the total RNA level remained stable during the incubation. Together, these results are showing the first comprehensive ecological evaluation across prokaryotic and eukaryotic microbial communities on thawing and freezing of soil by application of the TotalRNA technique.

AB - The active layer of soil overlaying permafrost in the Arctic is subjected to annual changes in temperature and soil chemistry, which we hypothesize to affect the overall soil microbial community. We investigated changes in soil microorganisms at different temperatures during warming and freezing of the active layer soil from Svalbard, Norway. Soil community data were obtained by direct shotgun sequencing of total extracted RNA. No changes in soil microbial communities were detected when warming from −10 to −2 °C or when freezing from −2 to −10 °C. In contrast, within a few days we observed changes when warming from −2 to +2 °C with a decrease in fungal rRNA and an increase in several OTUs belonging to Gemmatimonadetes, Bacteroidetes and Betaproteobacteria. Even more substantial changes occurred when incubating at 2 °C for 16 days, with declines in total fungal potential activity and decreases in oligotrophic members from Actinobacteria and Acidobacteria. Additionally, we detected an increase in transcriptome sequences of bacterial phyla Bacteriodetes, Firmicutes, Betaproteobacteria and Gammaproteobacteria—collectively presumed to be copiotrophic. Furthermore, we detected an increase in putative bacterivorous heterotrophic flagellates, likely due to predation upon the bacterial community via grazing. Although this grazing activity may explain relatively large changes in the bacterial community composition, no changes in total 16S rRNA gene copy number were observed and the total RNA level remained stable during the incubation. Together, these results are showing the first comprehensive ecological evaluation across prokaryotic and eukaryotic microbial communities on thawing and freezing of soil by application of the TotalRNA technique.

U2 - 10.1038/s41396-019-0351-x

DO - 10.1038/s41396-019-0351-x

M3 - Journal article

C2 - 30692629

AN - SCOPUS:85060816205

VL - 13

SP - 1345

EP - 1359

JO - I S M E Journal

JF - I S M E Journal

SN - 1751-7362

ER -