Previous Article | Next Article ![]()
Appl. Environ. Microbiol., Jul 1995, 2720-2726, Vol 61, No. 7
RP Kiene and ME Hines
Peat bogs dominated by Sphagnum spp. have relatively high areal rates of
dimethyl sulfide (DMS) emission to the atmosphere. DMS was produced in
anoxic slurries of Sphagnum peat with a linear time course and with an
average rate of 40.4 (range, 22.0 to 68.6) nmol per liter of slurry
(middot) day(sup-1) observed in nine batches of slurry. Methanethiol (MeSH)
was produced at roughly similar rates over the typical 4- to 8-day
incubations. DMS and MeSH production in these acidic (pH 4.2 to 4.6) peats
were biological, as they were stopped completely by autoclaving and
inhibited strongly by addition of antibiotics and 500 (mu)M chloroform.
Endogenous DMS production may be due to the degradation of
S-methyl-methionine, dimethyl sulfoxide, or methoxyaromatic compounds
(e.g., syringic acid), each of which stimulated DMS formation when added at
5 to 10 (mu)M concentrations. However, on the basis of the high rates of
thiol (MeSH and ethanethiol) methylation activity that we observed and the
availability of endogenous MeSH, we suggest that methylation of MeSH is the
major pathway leading to DMS formation in anaerobic peat. Solid-phase
adsorption of MeSH plays a key role in its availability for biomethylation
reactions. Additions of acetate (1.5 mM) or compounds which could cause
acetate to accumulate (e.g., glucose, alanine, and 2-bromoethanesulfonate)
suppressed DMS formation. It is likely that acetogenic bacteria are
involved in DMS formation, but our data are insufficient to allow firm
conclusions about the metabolic pathways or organisms involved. Our
observations are the first which point to the methylation of MeSH as the
major mechanism for endogenous DMS production in any environment. The rates
of net DMS production observed are sufficient to explain the relatively
high fluxes of DMS emitted to the atmosphere from Sphagnum sp.-dominated
wetlands.
Copyright © 1995, American Society for Microbiology
Microbial Formation of Dimethyl Sulfide in Anoxic Sphagnum Peat
Department of Marine Sciences, University of South Alabama, Mobile, Alabama 36688; Alabama Marine Environmental Sciences Consortium, Dauphin Island Sea Lab, Dauphin Island, Alabama 36528; and Institute for the Study of Earth, Oceans, and Space, University of New Hampshire, Durham, New Hampshire 03824
This article has been cited by other articles:
Copyright © 2009 by the American Society for Microbiology. For an alternate route to Journals.ASM.org, visit: http://intl-journals.asm.org | More Info»