Journal
FEMS MICROBIOLOGY ECOLOGY
Volume 74, Issue 3, Pages 655-668Publisher
OXFORD UNIV PRESS
DOI: 10.1111/j.1574-6941.2010.00978.x
Keywords
Hg methylation; Sphagnum moss mats; sulfate-reducing bacteria; acidic Adirondack lake wetland
Categories
Funding
- National Science Foundation [ATM 0322022]
- New Jersey Water Resources Research Institute
Ask authors/readers for more resources
Processes leading to the bioaccumulation of methylmercury (MeHg) in northern wetlands are largely unknown. We have studied various ecological niches within a remote, acidic forested lake ecosystem in the southwestern Adirondacks, NY, to discover that mats comprised of Sphagnum moss were a hot spot for mercury (Hg) and MeHg accumulation (190.5 and 18.6 ng g-1 dw, respectively). Furthermore, significantly higher potential methylation rates were measured in Sphagnum mats as compared with other sites within Sunday Lake's ecosystem. Although MPN estimates showed a low biomass of sulfate-reducing bacteria (SRB), 2.8 x 104 cells mL-1 in mat samples, evidence consisting of (1) a twofold stimulation of potential methylation by the addition of sulfate, (2) a significant decrease in Hg methylation in the presence of the sulfate reduction inhibitor molybdate, and (3) presence of dsrAB-like genes in mat DNA extracts, suggested that SRB were involved in Hg methylation. Sequencing of dsrB genes indicated that novel SRB, incomplete oxidizers including Desulfobulbus spp. and Desulfovibrio spp., and syntrophs dominated the sulfate-reducing guild in the Sphagnum moss mat. Sphagnum, a bryophyte dominating boreal peatlands, and its associated microbial communities appear to play an important role in the production and accumulation of MeHg in high-latitude ecosystems.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available