Ronald Oremland (Former Employee)
Science and Products
Filter Total Items: 118
Reduction of elemental selenium to selenide: Experiments with anoxic sediments and bacteria that respire Se-oxyanions
A selenite-respiring bacterium, Bacillus selenitireducens, produced significant levels of Se(-II) (as aqueous HSe−) when supplied with Se(0). B. selenitireducens was also able to reduce selenite [Se(IV)] through Se(0) to Se(-II). Reduction of Se(0) by B. selenitireducens was more rapid in cells grown on colloidal sulfur [S(0)] or Se(IV) as their electron acceptor than for cell lines grown on fumar
Authors
M.J. Herbel, J.S. Blum, R.S. Oremland, S.E. Borglin
The ecology of arsenic
Arsenic is a metalloid whose name conjures up images of murder. Nonetheless, certain prokaryotes use arsenic oxyanions for energy generation, either by oxidizing arsenite or by respiring arsenate. These microbes are phylogenetically diverse and occur in a wide range of habitats. Arsenic cycling may take place in the absence of oxygen and can contribute to organic matter oxidation. In aquifers, the
Authors
Ronald S. Oremland, John F. Stolz
Leisingera methylohalidivorans gen. nov., sp. nov., a marine methylotroph that grows on methyl bromide
A marine methylotroph, designated strain MB2T, was isolated for its ability to grow on methyl bromide as a sole carbon and energy source. Methyl chloride and methyl iodide also supported growth, as did methionine and glycine betaine. A limited amount of growth was observed with dimethyl sulfide. Growth was also noted with unidentified components of the complex media marine broth 2216, yeast extrac
Authors
J.K. Schaefer, K.D. Goodwin, I.R. McDonald, J.C. Murrell, Ronald S. Oremland
Distribution, production, and ecophysiology of Picocystis strain ML in Mono Lake, California
A recently described unicellular chlorophytic alga isolated from meromictic Mono Lake, California, occupies a niche that spans two environments: the upper oxic mixolimnion and the deeper anoxic and highly reducing monimolimnion. This organism, Picocystis sp. strain ML, accounts for nearly 25% of the primary production during the winter bloom and more than 50% at other times of the year. In incubat
Authors
Collin S. Roesler, Charles W. Culbertson, Stacey M. Etheridge, Ralf Goericke, Ronald P. Kiene, Laurence G. Miller, Ronald S. Oremland
Anaerobic oxidation of arsenite in Mono Lake water and by a facultative, arsenite-oxidizing chemoautotroph, strain MLHE-1
Arsenite [As(III)]-enriched anoxic bottom water from Mono Lake, California, produced arsenate [As(V)] during incubation with either nitrate or nitrite. No such oxidation occurred in killed controls or in live samples incubated without added nitrate or nitrite. A small amount of biological As(III) oxidation was observed in samples amended with Fe(III) chelated with nitrolotriacetic acid, although s
Authors
Ronald S. Oremland, S.E. Hoeft, J.M. Santini, N. Bano, R.A. Hollibaugh, J.T. Hollibaugh
Bacterial respiration of arsenate and its significance in the environment
No abstract available.
Authors
Ronald S. Oremland, Diane Newman, B.W. Kail, J.F. Stolz
Consumption of tropospheric levels of methyl bromide by C1 compound-utilizing bacteria and comparison to saturation kinetics
Pure cultures of methylotrophs and methanotrophs are known to oxidize methyl bromide (MeBr); however, their ability to oxidize tropospheric concentrations (parts per trillion by volume [pptv]) has not been tested. Methylotrophs and methanotrophs were able to consume MeBr provided at levels that mimicked the tropospheric mixing ratio of MeBr (12 pptv) at equilibrium with surface waters (≈2 pM). Kin
Authors
K.D. Goodwin, R.K. Varner, P.M. Crill, Ronald S. Oremland
Diversity of anaerobic halophilic microorganisms
Life in the presence of high salt concentrations is compatible with life in the absence of oxygen. Halophilic and halotolerant anaerobic prokaryotes are found both in the archaeal and in the bacterial domain, and they display a great metabolic diversity. Many of the representatives of the Halobacteriales (Archaea), which are generally considered aerobes, have the potential of anaerobic growth. Som
Authors
Aharon Oren, Ronald S. Oremland
Methyl-mercury degradation pathways: A comparison among three mercury impacted ecosystems
We examined microbial methylmercury (MeHg) degradation in sediment of the Florida Everglades, Carson River (NV), and San Carlos Creek (CA), three freshwater environments that differ in the extent and type of mercury contamination and sediment biogeochemistry. Degradation rate constant (kdeg) values increased with total mercury (Hgt) contamination both among and within ecosystems. The highest kdeg'
Authors
M. Marvin-DiPasquale, J. Agee, C. Mcgowan, R.S. Oremland, M. Thomas, D. Krabbenhoft, C.C. Gilmour
Mobilization of arsenite by dissimilatory reduction of adsorbed arsenate
Sulfurospirillum barnesii is capable of anaerobic growth using ferric iron or arsenate as electron acceptors. Cell suspensions of S. barnesii were able to reduce arsenate to arsenite when the former oxyanion was dissolved in solution, or when it was adsorbed onto the surface of ferrihydrite, a common soil mineral, by a variety of mechanisms (e.g., coprecipitation, presorption). Reduction of Fe(III
Authors
J. Zobrist, P.R. Dowdle, J.A. Davis, Ronald S. Oremland
Radiotracer studies of bacterial methanogenesis in sediments from the Dead Sea and Solar Lake (Sinai)
No abstract available.
Authors
Mark Marvin-DePasquale, Yoram. Geological Survey (U.S.) Cohen, Ronald S. Oremland, A. Oren
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Filter Total Items: 118
Reduction of elemental selenium to selenide: Experiments with anoxic sediments and bacteria that respire Se-oxyanions
A selenite-respiring bacterium, Bacillus selenitireducens, produced significant levels of Se(-II) (as aqueous HSe−) when supplied with Se(0). B. selenitireducens was also able to reduce selenite [Se(IV)] through Se(0) to Se(-II). Reduction of Se(0) by B. selenitireducens was more rapid in cells grown on colloidal sulfur [S(0)] or Se(IV) as their electron acceptor than for cell lines grown on fumarAuthorsM.J. Herbel, J.S. Blum, R.S. Oremland, S.E. BorglinThe ecology of arsenic
Arsenic is a metalloid whose name conjures up images of murder. Nonetheless, certain prokaryotes use arsenic oxyanions for energy generation, either by oxidizing arsenite or by respiring arsenate. These microbes are phylogenetically diverse and occur in a wide range of habitats. Arsenic cycling may take place in the absence of oxygen and can contribute to organic matter oxidation. In aquifers, theAuthorsRonald S. Oremland, John F. StolzLeisingera methylohalidivorans gen. nov., sp. nov., a marine methylotroph that grows on methyl bromide
A marine methylotroph, designated strain MB2T, was isolated for its ability to grow on methyl bromide as a sole carbon and energy source. Methyl chloride and methyl iodide also supported growth, as did methionine and glycine betaine. A limited amount of growth was observed with dimethyl sulfide. Growth was also noted with unidentified components of the complex media marine broth 2216, yeast extracAuthorsJ.K. Schaefer, K.D. Goodwin, I.R. McDonald, J.C. Murrell, Ronald S. OremlandDistribution, production, and ecophysiology of Picocystis strain ML in Mono Lake, California
A recently described unicellular chlorophytic alga isolated from meromictic Mono Lake, California, occupies a niche that spans two environments: the upper oxic mixolimnion and the deeper anoxic and highly reducing monimolimnion. This organism, Picocystis sp. strain ML, accounts for nearly 25% of the primary production during the winter bloom and more than 50% at other times of the year. In incubatAuthorsCollin S. Roesler, Charles W. Culbertson, Stacey M. Etheridge, Ralf Goericke, Ronald P. Kiene, Laurence G. Miller, Ronald S. OremlandAnaerobic oxidation of arsenite in Mono Lake water and by a facultative, arsenite-oxidizing chemoautotroph, strain MLHE-1
Arsenite [As(III)]-enriched anoxic bottom water from Mono Lake, California, produced arsenate [As(V)] during incubation with either nitrate or nitrite. No such oxidation occurred in killed controls or in live samples incubated without added nitrate or nitrite. A small amount of biological As(III) oxidation was observed in samples amended with Fe(III) chelated with nitrolotriacetic acid, although sAuthorsRonald S. Oremland, S.E. Hoeft, J.M. Santini, N. Bano, R.A. Hollibaugh, J.T. HollibaughBacterial respiration of arsenate and its significance in the environment
No abstract available.AuthorsRonald S. Oremland, Diane Newman, B.W. Kail, J.F. StolzConsumption of tropospheric levels of methyl bromide by C1 compound-utilizing bacteria and comparison to saturation kinetics
Pure cultures of methylotrophs and methanotrophs are known to oxidize methyl bromide (MeBr); however, their ability to oxidize tropospheric concentrations (parts per trillion by volume [pptv]) has not been tested. Methylotrophs and methanotrophs were able to consume MeBr provided at levels that mimicked the tropospheric mixing ratio of MeBr (12 pptv) at equilibrium with surface waters (≈2 pM). KinAuthorsK.D. Goodwin, R.K. Varner, P.M. Crill, Ronald S. OremlandDiversity of anaerobic halophilic microorganisms
Life in the presence of high salt concentrations is compatible with life in the absence of oxygen. Halophilic and halotolerant anaerobic prokaryotes are found both in the archaeal and in the bacterial domain, and they display a great metabolic diversity. Many of the representatives of the Halobacteriales (Archaea), which are generally considered aerobes, have the potential of anaerobic growth. SomAuthorsAharon Oren, Ronald S. OremlandMethyl-mercury degradation pathways: A comparison among three mercury impacted ecosystems
We examined microbial methylmercury (MeHg) degradation in sediment of the Florida Everglades, Carson River (NV), and San Carlos Creek (CA), three freshwater environments that differ in the extent and type of mercury contamination and sediment biogeochemistry. Degradation rate constant (kdeg) values increased with total mercury (Hgt) contamination both among and within ecosystems. The highest kdeg'AuthorsM. Marvin-DiPasquale, J. Agee, C. Mcgowan, R.S. Oremland, M. Thomas, D. Krabbenhoft, C.C. GilmourMobilization of arsenite by dissimilatory reduction of adsorbed arsenate
Sulfurospirillum barnesii is capable of anaerobic growth using ferric iron or arsenate as electron acceptors. Cell suspensions of S. barnesii were able to reduce arsenate to arsenite when the former oxyanion was dissolved in solution, or when it was adsorbed onto the surface of ferrihydrite, a common soil mineral, by a variety of mechanisms (e.g., coprecipitation, presorption). Reduction of Fe(IIIAuthorsJ. Zobrist, P.R. Dowdle, J.A. Davis, Ronald S. OremlandRadiotracer studies of bacterial methanogenesis in sediments from the Dead Sea and Solar Lake (Sinai)
No abstract available.AuthorsMark Marvin-DePasquale, Yoram. Geological Survey (U.S.) Cohen, Ronald S. Oremland, A. Oren