Research Watch: Mercury methylation/sulfate reduction rates

1999 ◽  
Vol 33 (19) ◽  
pp. 427A-427A
Keyword(s):  
Sulfate Reduction ◽  
Mercury Methylation ◽  
Sulfate Reduction Rates

Coupling mercury methylation rates to sulfate reduction rates in marine sediments

1999 ◽  
Vol 18 (7) ◽  
pp. 1362-1369 ◽  
Author(s):  
Jeffrey K. King ◽  
F. Michael Saunders ◽  
Richard F. Lee ◽  
Richard A. Jahnke
Keyword(s):  
Sulfate Reduction ◽  
Marine Sediments ◽  
Mercury Methylation ◽  
Sulfate Reduction Rates

Interactions between filamentous sulfur bacteria, sulfate reducing bacteria and poly-P accumulating bacteria in anaerobic-oxic activated sludge from a municipal plant

1998 ◽  
Vol 37 (4-5) ◽  
pp. 599-603 ◽  
Author(s):  
Ryoko Yamamoto-Ikemoto ◽  
Saburo Matsui ◽  
Tomoaki Komori ◽  
Edja. Kofi. Bosque-Hamilton
Keyword(s):  
Activated Sludge ◽  
Sulfate Reduction ◽  
Reduction Rate ◽  
Sulfate Reducing Bacteria ◽  
Sulfate Reduction Rate ◽  
Filamentous Bulking ◽  
Sulfate Reducing ◽  
Sulfur Bacteria ◽  
Sulfate Reduction Rates ◽  
Reducing Bacteria

The interactions between filamentous sulfur bacteria (FSB), sulfate reducing bacteria (SRB) and poly-P accumulating bacteria (PAB) in the activated sludge of a municipal plant operated under anaerobic-oxic conditions were examined in batch experiments using return sludge (RAS) and settled sewage. Phosphate release and sulfate reduction occurred simultaneously under anaerobic conditions. SRB were more sensitive to temperature changes than PAB. SRB played an important role in the decomposition of propionate to acetate. When the sulfate reduction rates were high, there was a tendency for the maximum release of phosphate also to be high. This was explained by the fact that PAB utilized the acetate produced by SRB. Sulfur oxidizing bacteria were sensitive to temperature change. When the sulfate reduction rate was high, the sulfide oxidizing rate was also high and filamentous bulking occurred. The results showed that sulfate reduction was a cause of filamentous bulking due to Type 021N that could utilize reduced sulfur.

scholarly journals Complex Microbial Communities Drive Iron and Sulfur Cycling in Arctic Fjord Sediments

2019 ◽  
Vol 85 (14) ◽  
Author(s):  
J. Buongiorno ◽  
L. C. Herbert ◽  
L. M. Wehrmann ◽  
A. B. Michaud ◽  
K. Laufer ◽  
...  
Keyword(s):  
Organic Matter ◽  
Primary Production ◽  
Sulfate Reduction ◽  
The Arctic ◽  
Sulfur Cycling ◽  
Glacial Retreat ◽  
Sulfate Reducing ◽  
Glacial Runoff ◽  
Sulfate Reduction Rates ◽  
Fjord Sediments

ABSTRACTGlacial retreat is changing biogeochemical cycling in the Arctic, where glacial runoff contributes iron for oceanic shelf primary production. We hypothesize that in Svalbard fjords, microbes catalyze intense iron and sulfur cycling in low-organic-matter sediments. This is because low organic matter limits sulfide generation, allowing iron mobility to the water column instead of precipitation as iron monosulfides. In this study, we tested this with high-depth-resolution 16S rRNA gene libraries in the upper 20 cm at two sites in Van Keulenfjorden, Svalbard. At the site closer to the glaciers, iron-reducingDesulfuromonadales, iron-oxidizingGallionellaandMariprofundus, and sulfur-oxidizingThiotrichalesandEpsilonproteobacteriawere abundant above a 12-cm depth. Below this depth, the relative abundances of sequences for sulfate-reducingDesulfobacteraceaeandDesulfobulbaceaeincreased. At the outer station, the switch from iron-cycling clades to sulfate reducers occurred at shallower depths (∼5 cm), corresponding to higher sulfate reduction rates. Relatively labile organic matter (shown by δ13C and C/N ratios) was more abundant at this outer site, and ordination analysis suggested that this affected microbial community structure in surface sediments. Network analysis revealed more correlations between predicted iron- and sulfur-cycling taxa and with uncultured clades proximal to the glacier. Together, these results suggest that complex microbial communities catalyze redox cycling of iron and sulfur, especially closer to the glacier, where sulfate reduction is limited due to low availability of organic matter. Diminished sulfate reduction in upper sediments enables iron to flux into the overlying water, where it may be transported to the shelf.IMPORTANCEGlacial runoff is a key source of iron for primary production in the Arctic. In the fjords of the Svalbard archipelago, glacial retreat is predicted to stimulate phytoplankton blooms that were previously restricted to outer margins. Decreased sediment delivery and enhanced primary production have been hypothesized to alter sediment biogeochemistry, wherein any free reduced iron that could potentially be delivered to the shelf will instead become buried with sulfide generated through microbial sulfate reduction. We support this hypothesis with sequencing data that showed increases in the relative abundance of sulfate reducing taxa and sulfate reduction rates with increasing distance from the glaciers in Van Keulenfjorden, Svalbard. Community structure was driven by organic geochemistry, suggesting that enhanced input of organic material will stimulate sulfate reduction in interior fjord sediments as glaciers continue to recede.

scholarly journals Shifts in mercury methylation across a peatland chronosequence: From sulfate reduction to methanogenesis and syntrophy

2020 ◽  
Vol 387 ◽  
pp. 121967 ◽  
Author(s):  
Haiyan Hu ◽  
Baolin Wang ◽  
Andrea G. Bravo ◽  
Erik Björn ◽  
Ulf Skyllberg ◽  
...  
Keyword(s):  
Sulfate Reduction ◽  
Mercury Methylation

scholarly journals Sulfur Isotope Enrichment during Maintenance Metabolism in the Thermophilic Sulfate-Reducing Bacterium Desulfotomaculum putei

2009 ◽  
Vol 75 (17) ◽  
pp. 5621-5630 ◽  
Author(s):  
Mark M. Davidson ◽  
M. E. Bisher ◽  
Lisa M. Pratt ◽  
Jon Fong ◽  
Gordon Southam ◽  
...  
Keyword(s):  
Sulfate Reduction ◽  
Batch Culture ◽  
Marine Sediments ◽  
Maintenance Phase ◽  
Laboratory Culture ◽  
Specific Rate ◽  
Culture Vessel ◽  
Isotope Enrichment ◽  
Sulfate Reducing ◽  
Sulfate Reduction Rates

ABSTRACT Values of Δ34S ( \batchmode \documentclass[fleqn,10pt,legalpaper]{article} \usepackage{amssymb} \usepackage{amsfonts} \usepackage{amsmath} \pagestyle{empty} \begin{document} \({=}{\delta}^{34}S_{HS}{-}{\delta}^{34}S_{SO_{4}}\) \end{document} , where δ34SHS and \batchmode \documentclass[fleqn,10pt,legalpaper]{article} \usepackage{amssymb} \usepackage{amsfonts} \usepackage{amsmath} \pagestyle{empty} \begin{document} \({\delta}^{34}S_{SO_{4}}\) \end{document} indicate the differences in the isotopic compositions of the HS− and SO4 2− in the eluent, respectively) for many modern marine sediments are in the range of −55 to −75‰, much greater than the −2 to −46‰ ε34S (kinetic isotope enrichment) values commonly observed for microbial sulfate reduction in laboratory batch culture and chemostat experiments. It has been proposed that at extremely low sulfate reduction rates under hypersulfidic conditions with a nonlimited supply of sulfate, isotopic enrichment in laboratory culture experiments should increase to the levels recorded in nature. We examined the effect of extremely low sulfate reduction rates and electron donor limitation on S isotope fractionation by culturing a thermophilic, sulfate-reducing bacterium, Desulfotomaculum putei, in a biomass-recycling culture vessel, or “retentostat.” The cell-specific rate of sulfate reduction and the specific growth rate decreased progressively from the exponential phase to the maintenance phase, yielding average maintenance coefficients of 10−16 to 10−18 mol of SO4 cell−1 h−1 toward the end of the experiments. Overall S mass and isotopic balance were conserved during the experiment. The differences in the δ34S values of the sulfate and sulfide eluting from the retentostat were significantly larger, attaining a maximum Δ34S of −20.9‰, than the −9.7‰ observed during the batch culture experiment, but differences did not attain the values observed in marine sediments.

scholarly journals Relative contributions of mercury bioavailability and microbial growth rate on net methylmercury production by anaerobic mixed cultures

2015 ◽  
Vol 17 (9) ◽  
pp. 1568-1577 ◽  
Author(s):  
Katarzyna H. Kucharzyk ◽  
Marc A. Deshusses ◽  
Kaitlyn A. Porter ◽  
Heileen Hsu-Kim
Keyword(s):  
Growth Rate ◽  
Sulfate Reduction ◽  
Microbial Growth ◽  
Mixed Cultures ◽  
Net Production ◽  
Sulfate Reduction Rates ◽  
Methylmercury Production

Net production of methylmercury correlated with sulfate reduction rates in cultures exposed to dissolved Hg, but was insensitive to sulfate reduction rates for cultures exposed to nanoparticulate HgS.

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