Ronald Oremland (Former Employee)
Science and Products
Filter Total Items: 120
Bacterial Cycling of Methyl Halides Bacterial Cycling of Methyl Halides
This chapter focuses on the monohalogenated methanes methyl chloride (MeCl) and methyl bromide (MeBr), their natural and anthropogenic sources, and their degradation by microorganisms, specifically by aerobic bacteria that can use MeBr and MeCl as sole source of carbon and energy. The biogeochemical cycle of methyl halides and the microbiology, biochemistry, genetics, and...
Authors
Hendrik Schafer, Laurence G. Miller, Ronald S. Oremland, Colin Murrell
Effects of imposed salinity gradients on dissimilatory arsenate reduction, sulfate reduction, and other microbial processes in sediments from two California soda lakes Effects of imposed salinity gradients on dissimilatory arsenate reduction, sulfate reduction, and other microbial processes in sediments from two California soda lakes
Salinity effects on microbial community structure and on potential rates of arsenate reduction, arsenite oxidation, sulfate reduction, denitrification, and methanogenesis were examined in sediment slurries from two California soda lakes. We conducted experiments with Mono Lake and Searles Lake sediments over a wide range of salt concentrations (25 to 346 g liter−1). With the exception of...
Authors
T.R. Kulp, S. Han, C.W. Saltikov, B.D. Lanoil, K. Zargar, Ron Oremland
Formation of tellurium nanocrystals during anaerobic growth of bacteria that use Te oxyanions as respiratory electron acceptors Formation of tellurium nanocrystals during anaerobic growth of bacteria that use Te oxyanions as respiratory electron acceptors
Certain toxic elements support the metabolism of diverse prokaryotes by serving as respiratory electron acceptors for growth. Here, we demonstrate that two anaerobes previously shown to be capable of respiring oxyanions of selenium also achieve growth by reduction of either tellurate [Te(VI)] or tellurite [Te(IV)] to elemental tellurium [Te(0)]. This reduction achieves a sizeable stable...
Authors
Shaun M. Baesman, Thomas D. Bullen, J. Dewald, Donghui Zhang, S. Curran, F.S. Islam, T.J. Beveridge, Ronald S. Oremland
Arsenic in ground water: A review of current knowledge and relation to the CALFED solution area with recommendations for needed research Arsenic in ground water: A review of current knowledge and relation to the CALFED solution area with recommendations for needed research
Ground water with arsenic concentrations greater than the U.S. Environmental Protection Agency drinking water standard exists throughout much of the CALFED solution area. These high concentrations are of con-cern from the standpoint of both existing water supply and development of conjunctive use projects. Much is known about arsenic mobility in ground water subject to different...
Authors
Alan H. Welch, Ronald S. Oremland, James A. Davis, Sharon A. Watkins
Microbial transformations of arsenic in the environment: From soda lakes to aquifers Microbial transformations of arsenic in the environment: From soda lakes to aquifers
Arsenic is a highly toxic element that supports a surprising range of biogeochemical transformations. The biochemical basis of these microbial interactions is described, with an emphasis on energy-yielding redox biotransformations that cycle between the As5+ and As3+ oxidation states. The subsequent impact of As3+-oxidising and As 5+-reducing prokaryotes on the chemistry of selected...
Authors
J.R. Lloyd, R.S. Oremland
Dissimilatory arsenate and sulfate reduction in sediments of two hypersaline, arsenic-rich soda lakes: Mono and Searles Lakes, California Dissimilatory arsenate and sulfate reduction in sediments of two hypersaline, arsenic-rich soda lakes: Mono and Searles Lakes, California
A radioisotope method was devised to study bacterial respiratory reduction of arsenate in sediments. The following two arsenic-rich soda lakes in California were chosen for comparison on the basis of their different salinities: Mono Lake (∼90 g/liter) and Searles Lake (∼340 g/liter). Profiles of arsenate reduction and sulfate reduction were constructed for both lakes. Reduction of [73As...
Authors
T.R. Kulp, S.E. Hoeft, L.G. Miller, C. Saltikov, J.N. Murphy, S. Han, B. Lanoil, R.S. Oremland
Science and Products
Filter Total Items: 120
Bacterial Cycling of Methyl Halides Bacterial Cycling of Methyl Halides
This chapter focuses on the monohalogenated methanes methyl chloride (MeCl) and methyl bromide (MeBr), their natural and anthropogenic sources, and their degradation by microorganisms, specifically by aerobic bacteria that can use MeBr and MeCl as sole source of carbon and energy. The biogeochemical cycle of methyl halides and the microbiology, biochemistry, genetics, and...
Authors
Hendrik Schafer, Laurence G. Miller, Ronald S. Oremland, Colin Murrell
Effects of imposed salinity gradients on dissimilatory arsenate reduction, sulfate reduction, and other microbial processes in sediments from two California soda lakes Effects of imposed salinity gradients on dissimilatory arsenate reduction, sulfate reduction, and other microbial processes in sediments from two California soda lakes
Salinity effects on microbial community structure and on potential rates of arsenate reduction, arsenite oxidation, sulfate reduction, denitrification, and methanogenesis were examined in sediment slurries from two California soda lakes. We conducted experiments with Mono Lake and Searles Lake sediments over a wide range of salt concentrations (25 to 346 g liter−1). With the exception of...
Authors
T.R. Kulp, S. Han, C.W. Saltikov, B.D. Lanoil, K. Zargar, Ron Oremland
Formation of tellurium nanocrystals during anaerobic growth of bacteria that use Te oxyanions as respiratory electron acceptors Formation of tellurium nanocrystals during anaerobic growth of bacteria that use Te oxyanions as respiratory electron acceptors
Certain toxic elements support the metabolism of diverse prokaryotes by serving as respiratory electron acceptors for growth. Here, we demonstrate that two anaerobes previously shown to be capable of respiring oxyanions of selenium also achieve growth by reduction of either tellurate [Te(VI)] or tellurite [Te(IV)] to elemental tellurium [Te(0)]. This reduction achieves a sizeable stable...
Authors
Shaun M. Baesman, Thomas D. Bullen, J. Dewald, Donghui Zhang, S. Curran, F.S. Islam, T.J. Beveridge, Ronald S. Oremland
Arsenic in ground water: A review of current knowledge and relation to the CALFED solution area with recommendations for needed research Arsenic in ground water: A review of current knowledge and relation to the CALFED solution area with recommendations for needed research
Ground water with arsenic concentrations greater than the U.S. Environmental Protection Agency drinking water standard exists throughout much of the CALFED solution area. These high concentrations are of con-cern from the standpoint of both existing water supply and development of conjunctive use projects. Much is known about arsenic mobility in ground water subject to different...
Authors
Alan H. Welch, Ronald S. Oremland, James A. Davis, Sharon A. Watkins
Microbial transformations of arsenic in the environment: From soda lakes to aquifers Microbial transformations of arsenic in the environment: From soda lakes to aquifers
Arsenic is a highly toxic element that supports a surprising range of biogeochemical transformations. The biochemical basis of these microbial interactions is described, with an emphasis on energy-yielding redox biotransformations that cycle between the As5+ and As3+ oxidation states. The subsequent impact of As3+-oxidising and As 5+-reducing prokaryotes on the chemistry of selected...
Authors
J.R. Lloyd, R.S. Oremland
Dissimilatory arsenate and sulfate reduction in sediments of two hypersaline, arsenic-rich soda lakes: Mono and Searles Lakes, California Dissimilatory arsenate and sulfate reduction in sediments of two hypersaline, arsenic-rich soda lakes: Mono and Searles Lakes, California
A radioisotope method was devised to study bacterial respiratory reduction of arsenate in sediments. The following two arsenic-rich soda lakes in California were chosen for comparison on the basis of their different salinities: Mono Lake (∼90 g/liter) and Searles Lake (∼340 g/liter). Profiles of arsenate reduction and sulfate reduction were constructed for both lakes. Reduction of [73As...
Authors
T.R. Kulp, S.E. Hoeft, L.G. Miller, C. Saltikov, J.N. Murphy, S. Han, B. Lanoil, R.S. Oremland