TY - JOUR
T1 - Glacial runoff promotes deep burial of sulfur cycling-associated microorganisms in marine sediments
AU - Pelikan, Claus
AU - Jaussi, Marion
AU - Wasmund, Kenneth
AU - Seidenkrantz, Marit Solveig
AU - Pearce, Christof
AU - Kuzyk, Zou Zou Anna
AU - Herbold, Craig W.
AU - Røy, Hans
AU - Kjeldsen, Kasper Urup
AU - Loy, Alexander
N1 - Funding Information:
We thank the crew of the R/V Sanna and the scientific party during the 2013 sampling campaign, and Britta Poulsen and Susanne Nielsen for laboratory technical assistance. We also thank David Waite for providing DsrAB sequences from MAGs that were included in the DsrAB reference tree. We acknowledge the use of imagery from the NASA Worldview application (https://worldview.earthdata.nasa.gov), part of the NASA Earth Observing System Data and Information System (EOSDIS). This is a contribution to the Arctic Science Partnership (ASP). Funding. The cruise was led by M-SS and funded by the Arctic Research Centre, Aarhus University. This work was financially supported by the Austrian Science Fund (P29426-B29 to KW and P25111-B22 to AL) and the Danish National Research Foundation (Grant DNRF104). M-SS was funded by the Independent Research Fund Denmark (Grant No. 7014-00113B/FNU).
Publisher Copyright:
© Copyright © 2019 Pelikan, Jaussi, Wasmund, Seidenkrantz, Pearce, Kuzyk, Herbold, Røy, Kjeldsen and Loy.
PY - 2019/11/7
Y1 - 2019/11/7
N2 - Marine fjords with active glacier outlets are hot spots for organic matter burial in the sediments and subsequent microbial mineralization. Here, we investigated controls on microbial community assembly in sub-arctic glacier-influenced (GI) and non-glacier-influenced (NGI) marine sediments in the Godthåbsfjord region, south-western Greenland. We used a correlative approach integrating 16S rRNA gene and dissimilatory sulfite reductase (dsrB) amplicon sequence data over six meters of depth with biogeochemistry, sulfur-cycling activities, and sediment ages. GI sediments were characterized by comparably high sedimentation rates and had “young” sediment ages of <500 years even at 6 m sediment depth. In contrast, NGI stations reached ages of approximately 10,000 years at these depths. Sediment age-depth relationships, sulfate reduction rates (SRR), and C/N ratios were strongly correlated with differences in microbial community composition between GI and NGI sediments, indicating that age and diagenetic state were key drivers of microbial community assembly in subsurface sediments. Similar bacterial and archaeal communities were present in the surface sediments of all stations, whereas only in GI sediments were many surface taxa also abundant through the whole sediment core. The relative abundance of these taxa, including diverse Desulfobacteraceae members, correlated positively with SRRs, indicating their active contributions to sulfur-cycling processes. In contrast, other surface community members, such as Desulfatiglans, Atribacteria, and Chloroflexi, survived the slow sediment burial at NGI stations and dominated in the deepest sediment layers. These taxa are typical for the energy-limited marine deep biosphere and their relative abundances correlated positively with sediment age. In conclusion, our data suggests that high rates of sediment accumulation caused by glacier runoff and associated changes in biogeochemistry, promote persistence of sulfur-cycling activity and burial of a larger fraction of the surface microbial community into the deep subsurface.
AB - Marine fjords with active glacier outlets are hot spots for organic matter burial in the sediments and subsequent microbial mineralization. Here, we investigated controls on microbial community assembly in sub-arctic glacier-influenced (GI) and non-glacier-influenced (NGI) marine sediments in the Godthåbsfjord region, south-western Greenland. We used a correlative approach integrating 16S rRNA gene and dissimilatory sulfite reductase (dsrB) amplicon sequence data over six meters of depth with biogeochemistry, sulfur-cycling activities, and sediment ages. GI sediments were characterized by comparably high sedimentation rates and had “young” sediment ages of <500 years even at 6 m sediment depth. In contrast, NGI stations reached ages of approximately 10,000 years at these depths. Sediment age-depth relationships, sulfate reduction rates (SRR), and C/N ratios were strongly correlated with differences in microbial community composition between GI and NGI sediments, indicating that age and diagenetic state were key drivers of microbial community assembly in subsurface sediments. Similar bacterial and archaeal communities were present in the surface sediments of all stations, whereas only in GI sediments were many surface taxa also abundant through the whole sediment core. The relative abundance of these taxa, including diverse Desulfobacteraceae members, correlated positively with SRRs, indicating their active contributions to sulfur-cycling processes. In contrast, other surface community members, such as Desulfatiglans, Atribacteria, and Chloroflexi, survived the slow sediment burial at NGI stations and dominated in the deepest sediment layers. These taxa are typical for the energy-limited marine deep biosphere and their relative abundances correlated positively with sediment age. In conclusion, our data suggests that high rates of sediment accumulation caused by glacier runoff and associated changes in biogeochemistry, promote persistence of sulfur-cycling activity and burial of a larger fraction of the surface microbial community into the deep subsurface.
KW - arctic
KW - deep biosphere
KW - glacial impact
KW - Greenland
KW - marine sediment
KW - microbial community assembly
KW - sulfate-reducing microorganisms
UR - http://www.scopus.com/inward/record.url?scp=85075581969&partnerID=8YFLogxK
U2 - 10.3389/fmicb.2019.02558
DO - 10.3389/fmicb.2019.02558
M3 - Article
AN - SCOPUS:85075581969
SN - 1664-302X
VL - 10
JO - Frontiers in Microbiology
JF - Frontiers in Microbiology
M1 - 2558
ER -