Ronald Oremland (Former Employee)
Science and Products
Filter Total Items: 119
Arsenic, microbes and contaminated aquifers
The health of tens of millions of people world-wide is at risk from drinking arsenic-contaminated well water. In most cases this arsenic occurs naturally within the sub-surface aquifers, rather than being derived from identifiable point sources of pollution. The mobilization of arsenic into the aqueous phase is the first crucial step in a process that eventually leads to human arsenicosis. Increas
Authors
Ronald S. Oremland, John F. Stolz
Genus sulfurospirillum
No abstract available.
Authors
J.F. Stolz, Ronald S. Oremland, B.J. Paster, F.E. Dewhirst, P. Vandamme
Aminobacter ciceronei sp. nov. and Aminobacter lissarensis sp. nov., isolated from various terrestrial environments
The bacterial strains IMB-1T and CC495T, which are capable of growth on methyl chloride (CH3Cl, chloromethane) and methyl bromide (CH3Br, bromomethane), were isolated from agricultural soil in California fumigated with CH3Br, and woodland soil in Northern Ireland, respectively. Two pesticide-/herbicide-degrading bacteria, strains ER2 and C147, were isolated from agricultural soil in Canada. Strain
Authors
I.R. McDonald, P. Kampfer, E. Topp, K.L. Warner, M.J. Cox, Hancock T.L. Connell, L.G. Miller, M.J. Larkin, V. Ducrocq, C. Coulter, D.B. Harper, J.C. Murrell, R.S. Oremland
Microbiology: A microbial arsenic cycle in a salt-saturated, extreme environment
Searles Lake is a salt-saturated, alkaline brine unusually rich in the toxic element arsenic. Arsenic speciation changed from arsenate [As(V)] to arsenite [As(III)] with sediment depth. Incubated anoxic sediment slurries displayed dissimilatory As(V)-reductase activity that was markedly stimulated by H2 or sulfide, whereas aerobic slurries had rapid As(III)-oxidase activity. An anaerobic, extremel
Authors
R.S. Oremland, T.R. Kulp, J.S. Blum, S.E. Hoeft, S. Baesman, L.G. Miller, J.F. Stolz
Whither or wither geomicrobiology in the era of 'community metagenomics'
Molecular techniques are valuable tools that can improve our understanding of the structure of microbial communities. They provide the ability to probe for life in all niches of the biosphere, perhaps even supplanting the need to cultivate microorganisms or to conduct ecophysiological investigations. However, an overemphasis and strict dependence on such large information-driven endeavours as envi
Authors
R.S. Oremland, D.G. Capone, J.F. Stolz, J. Fuhrman
Dissimilatory arsenate reduction with sulfide as the electron donor--Experiments with Mono Lake water and isolation of strain MLMS-1, a chemoautotrophic arsenate-respirer
Anoxic bottom water from Mono Lake, California, can biologically reduce added arsenate without any addition of electron donors. Of the possible in situ inorganic electron donors present, only sulfide was sufficiently abundant to drive this reaction. We tested the ability of sulfide to serve as an electron donor for arsenate reduction in experiments with lake water. Reduction of arsenate to arsenit
Authors
Shelley E. Hoeft, Thomas R. Kulp, John F. Stolz, James T. Hollibaugh, Ronald S. Oremland
The microbial arsenic cycle in Mono Lake, California
Significant concentrations of dissolved inorganic arsenic can be found in the waters of a number of lakes located in the western USA and in other water bodies around the world. These lakes are often situated in arid, volcanic terrain. The highest concentrations of arsenic occur in hypersaline, closed basin soda lakes and their remnant brines. Although arsenic is a well-known toxicant to eukaryotes
Authors
Ronald S. Oremland, John F. Stolz, James T. Hollibaugh
Redox transformations of arsenic oxyanions in periphyton communities
Periphyton (Cladophora sp.) samples from a suburban stream lacking detectable dissolved As were able to reduce added As(V) to As(III) when incubated under anoxic conditions and, conversely, oxidized added As(III) to As(V) with aerobic incubation. Both types of activity were abolished in autoclaved controls, thereby demonstrating its biological nature. The reduction of As(V) was inhibited by chlora
Authors
T.R. Kulp, S.E. Hoeft, R.S. Oremland
Degradation of methyl bromide and methyl chloride in soil microcosms: Use of stable C isotope fractionation and stable isotope probing to identify reactions and the responsible microorganisms
Bacteria in soil microcosm experiments oxidized elevated levels of methyl chloride (MeCl) and methyl bromide (MeBr), the former compound more rapidly than the latter. MeBr was also removed by chemical reactions while MeCl was not. Chemical degradation dominated the early removal of MeBr and accounted for more than half of its total loss. Fractionation of stable carbon isotopes during chemical degr
Authors
L.G. Miller, K.L. Warner, S.M. Baesman, R.S. Oremland, I.R. McDonald, S. Radajewski, J.C. Murrell
Structural and spectral features of selenium nanospheres produced by Se-respiring bacteria
Certain anaerobic bacteria respire toxic selenium oxyanions and in doing so produce extracellular accumulations of elemental selenium [Se(0)]. We examined three physiologically and phylogenetically diverse species of selenate- and selenite-respiring bacteria, Sulfurospirillum barnesii, Bacillus selenitireducens, and Selenihalanaerobacter shriftii, for the occurrence of this phenomenon. When grown
Authors
R.S. Oremland, M.J. Herbel, J.S. Blum, S. Langley, T.J. Beveridge, P.M. Ajayan, T. Sutto, A.V. Ellis, S. Curran
Microbial degradation of atmospheric halocarbons
Halocarbons are present in the atmosphere at parts-per-trillion (ppt) mixing ratios and are represented by such substances as chlorofluorocarbons (CFCs), hydrochlolofluorocarbons (HCFCs), hydrofluorocarbons (HFCs), and methyl halides like methyl bromide (MeBr) and their further substituted halomethane analogues (e. g., dibromomethane, bromoform). Many Halocarbons have only an anthropogenic origin
Authors
Ronald S. Oremland
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
Science and Products
Filter Total Items: 119
Arsenic, microbes and contaminated aquifers
The health of tens of millions of people world-wide is at risk from drinking arsenic-contaminated well water. In most cases this arsenic occurs naturally within the sub-surface aquifers, rather than being derived from identifiable point sources of pollution. The mobilization of arsenic into the aqueous phase is the first crucial step in a process that eventually leads to human arsenicosis. Increas
Authors
Ronald S. Oremland, John F. Stolz
Genus sulfurospirillum
No abstract available.
Authors
J.F. Stolz, Ronald S. Oremland, B.J. Paster, F.E. Dewhirst, P. Vandamme
Aminobacter ciceronei sp. nov. and Aminobacter lissarensis sp. nov., isolated from various terrestrial environments
The bacterial strains IMB-1T and CC495T, which are capable of growth on methyl chloride (CH3Cl, chloromethane) and methyl bromide (CH3Br, bromomethane), were isolated from agricultural soil in California fumigated with CH3Br, and woodland soil in Northern Ireland, respectively. Two pesticide-/herbicide-degrading bacteria, strains ER2 and C147, were isolated from agricultural soil in Canada. Strain
Authors
I.R. McDonald, P. Kampfer, E. Topp, K.L. Warner, M.J. Cox, Hancock T.L. Connell, L.G. Miller, M.J. Larkin, V. Ducrocq, C. Coulter, D.B. Harper, J.C. Murrell, R.S. Oremland
Microbiology: A microbial arsenic cycle in a salt-saturated, extreme environment
Searles Lake is a salt-saturated, alkaline brine unusually rich in the toxic element arsenic. Arsenic speciation changed from arsenate [As(V)] to arsenite [As(III)] with sediment depth. Incubated anoxic sediment slurries displayed dissimilatory As(V)-reductase activity that was markedly stimulated by H2 or sulfide, whereas aerobic slurries had rapid As(III)-oxidase activity. An anaerobic, extremel
Authors
R.S. Oremland, T.R. Kulp, J.S. Blum, S.E. Hoeft, S. Baesman, L.G. Miller, J.F. Stolz
Whither or wither geomicrobiology in the era of 'community metagenomics'
Molecular techniques are valuable tools that can improve our understanding of the structure of microbial communities. They provide the ability to probe for life in all niches of the biosphere, perhaps even supplanting the need to cultivate microorganisms or to conduct ecophysiological investigations. However, an overemphasis and strict dependence on such large information-driven endeavours as envi
Authors
R.S. Oremland, D.G. Capone, J.F. Stolz, J. Fuhrman
Dissimilatory arsenate reduction with sulfide as the electron donor--Experiments with Mono Lake water and isolation of strain MLMS-1, a chemoautotrophic arsenate-respirer
Anoxic bottom water from Mono Lake, California, can biologically reduce added arsenate without any addition of electron donors. Of the possible in situ inorganic electron donors present, only sulfide was sufficiently abundant to drive this reaction. We tested the ability of sulfide to serve as an electron donor for arsenate reduction in experiments with lake water. Reduction of arsenate to arsenit
Authors
Shelley E. Hoeft, Thomas R. Kulp, John F. Stolz, James T. Hollibaugh, Ronald S. Oremland
The microbial arsenic cycle in Mono Lake, California
Significant concentrations of dissolved inorganic arsenic can be found in the waters of a number of lakes located in the western USA and in other water bodies around the world. These lakes are often situated in arid, volcanic terrain. The highest concentrations of arsenic occur in hypersaline, closed basin soda lakes and their remnant brines. Although arsenic is a well-known toxicant to eukaryotes
Authors
Ronald S. Oremland, John F. Stolz, James T. Hollibaugh
Redox transformations of arsenic oxyanions in periphyton communities
Periphyton (Cladophora sp.) samples from a suburban stream lacking detectable dissolved As were able to reduce added As(V) to As(III) when incubated under anoxic conditions and, conversely, oxidized added As(III) to As(V) with aerobic incubation. Both types of activity were abolished in autoclaved controls, thereby demonstrating its biological nature. The reduction of As(V) was inhibited by chlora
Authors
T.R. Kulp, S.E. Hoeft, R.S. Oremland
Degradation of methyl bromide and methyl chloride in soil microcosms: Use of stable C isotope fractionation and stable isotope probing to identify reactions and the responsible microorganisms
Bacteria in soil microcosm experiments oxidized elevated levels of methyl chloride (MeCl) and methyl bromide (MeBr), the former compound more rapidly than the latter. MeBr was also removed by chemical reactions while MeCl was not. Chemical degradation dominated the early removal of MeBr and accounted for more than half of its total loss. Fractionation of stable carbon isotopes during chemical degr
Authors
L.G. Miller, K.L. Warner, S.M. Baesman, R.S. Oremland, I.R. McDonald, S. Radajewski, J.C. Murrell
Structural and spectral features of selenium nanospheres produced by Se-respiring bacteria
Certain anaerobic bacteria respire toxic selenium oxyanions and in doing so produce extracellular accumulations of elemental selenium [Se(0)]. We examined three physiologically and phylogenetically diverse species of selenate- and selenite-respiring bacteria, Sulfurospirillum barnesii, Bacillus selenitireducens, and Selenihalanaerobacter shriftii, for the occurrence of this phenomenon. When grown
Authors
R.S. Oremland, M.J. Herbel, J.S. Blum, S. Langley, T.J. Beveridge, P.M. Ajayan, T. Sutto, A.V. Ellis, S. Curran
Microbial degradation of atmospheric halocarbons
Halocarbons are present in the atmosphere at parts-per-trillion (ppt) mixing ratios and are represented by such substances as chlorofluorocarbons (CFCs), hydrochlolofluorocarbons (HCFCs), hydrofluorocarbons (HFCs), and methyl halides like methyl bromide (MeBr) and their further substituted halomethane analogues (e. g., dibromomethane, bromoform). Many Halocarbons have only an anthropogenic origin
Authors
Ronald S. Oremland
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