Experimental sulfate amendment alters peatland bacterial community structure.
As part of a long-term, peatland-scale sulfate addition experiment, the impact of varying sulfate deposition on bacterial community responses was assessed using 16S tag encoded pyrosequencing. In three separate areas of the peatland, sulfate manipulations included an eight year quadrupling of atmospheric sulfate deposition (experimental), a 3-year recovery to background deposition following 5years of elevated deposition (recovery), and a control area. Peat concentrations of methylmercury (MeHg), a bioaccumulative neurotoxin, were measured, the production of which is attributable to a growing list of microorganisms, including many sulfate-reducing Deltaproteobacteria. The total bacterial and Deltaproteobacterial community structures in the experimental treatment differed significantly from those in the control and recovery treatments that were either indistinguishable or very similar to one another. Notably, the relatively rapid return (within three years) of bacterial community structure in the recovery treatment to a state similar to the control, demonstrates significant resilience of the peatland bacterial community to changes in atmospheric sulfate deposition. Changes in MeHg accumulation between sulfate treatments correlated with changes in the Deltaproteobacterial community, suggesting that sulfate may affect MeHg production through changes in the community structure of this group.
Department of Physical and Environmental Sciences, University of Toronto Scarborough, Scarborough, Ontario, Canada.
R J S
RJS
Strickman
Department of Physical and Environmental Sciences, University of Toronto Scarborough, Scarborough, Ontario, Canada.
R R
RR
Fulthorpe
St. Croix Watershed Research Station, Science Museum of Minnesota, Marine on St. Croix, MN, United States.
J K
JK
Coleman Wasik
St. Croix Watershed Research Station, Science Museum of Minnesota, Marine on St. Croix, MN, United States.
D R
DR
Engstrom
Department of Physical and Environmental Sciences, University of Toronto Scarborough, Scarborough, Ontario, Canada. Electronic address: carl.mitchell@mail.utoronto.ca.
C P J
CPJ
Mitchell
D000393:Air Pollutants / Q000032:analysis*; D001419:Bacteria; D001673:Biodegradation, Environmental; D020564:Deltaproteobacteria; D008767:Methylmercury Compounds / Q000032:analysis; D064307:Microbiota; D008910:Minnesota; D013431:Sulfates / Q000032:analysis*; D053833:Wetlands
D000393:Air Pollutants; D008767:Methylmercury Compounds; D013431:Sulfates
Mercury; Methylmercury; Microbial ecology; Sulfate reducing bacteria; Wetland