Shaun Baesman
Shaun Baesman is a Biologist for the USGS Water Resources Mission Area.
Science and Products
Detection of diazotrophy in the acetylene-fermenting anaerobe Pelobacter sp. strain SFB93
Acetylene (C2H2) is a trace constituent of the present Earth's oxidizing atmosphere, reflecting a mixture of terrestrial and marine emissions from anthropogenic, biomass-burning, and unidentified biogenic sources. Fermentation of acetylene was serendipitously discovered during C2H2 block assays of N2O reductase, and Pelobacter acetylenicus was shown to grow on C2H2 via acetylene hydratase (AH). AH
Authors
Denise M. Akob, Shaun Baesman, John M. Sutton, Janna L. Fierst, Adam Mumford, Yesha Shrestha, Amisha T. Poret-Peterson, Stacy C. Bennett, Darren S. Dunlap, Karl B. Haase, Ronald S. Oremland
Acetylene fuels TCE reductive dechlorination by defined Dehalococcoides/Pelobacter consortia
Acetylene (C2H2) can be generated in contaminated groundwater sites as a consequence of chemical degradation of trichloroethene (TCE) by in situ minerals, and C2H2 is known to inhibit bacterial dechlorination. In this study, we show that while high C2H2 (1.3 mM) concentrations reversibly inhibit reductive dechlorination of TCE by Dehalococcoides mccartyi isolates as well as enrichment cultures con
Authors
Xinwei Mao, Ronald S. Oremland, Tong Liu, Abigail A Landers, Shaun Baesman, Lisa Alvarez-Cohen
Stable carbon isotope fractionation during bacterial acetylene fermentation: Potential for life detection in hydrocarbon-rich volatiles of icy planet(oid)s
We report the first study of stable carbon isotope fractionation during microbial fermentation of acetylene (C2H2) in sediments, sediment enrichments, and bacterial cultures. Kinetic isotope effects (KIEs) averaged 3.7 ± 0.5‰ for slurries prepared with sediment collected at an intertidal mudflat in San Francisco Bay and 2.7 ± 0.2‰ for a pure culture of Pelobacter sp. isolated from these sediments.
Authors
Laurence Miller, Shaun Baesman, Ron Oremland
Methane oxidation and molecular characterization of methanotrophs from a former mercury mine impoundment
The Herman Pit, once a mercury mine, is an impoundment located in an active geothermal area. Its acidic waters are permeated by hundreds of gas seeps. One seep was sampled and found to be composed of mostly CO2 with some CH4 present. The δ13CH4 value suggested a complex origin for the methane: i.e., a thermogenic component plus a biological methanogenic portion. The relatively 12C-enriched CO2 sug
Authors
Shaun Baesman, Laurence G. Miller, Jeremy H. Wei, Yirang Cho, Emily D. Matys, Roger E. Summons, Paula V. Welander, Ronald S. Oremland
Methane oxidation linked to chlorite dismutation
We examined the potential for CH4 oxidation to be coupled with oxygen derived from the dissimilatory reduction of perchlorate, chlorate, or via chlorite (ClO−2) dismutation. Although dissimilatory reduction of ClO−4 and ClO−3 could be inferred from the accumulation of chloride ions either in spent media or in soil slurries prepared from exposed freshwater lake sediment, neither of these oxyanions
Authors
Laurence G. Miller, Shaun M. Baesman, Charlotte I. Carlström, John D. Coates, Ronald S. Oremland
A biogeochemical and genetic survey of acetylene fermentation by environmental samples and bacterial isolates
Anoxic samples (sediment and groundwater) from 13 chemically diverse field sites were assayed for their ability to consume acetylene (C2H2). Over incubation periods ranging from ˜ 10 to 80 days, selected samples from 7 of the 13 tested sites displayed significant C2H2 removal. No significant formation of ethylene was noted in these incubations; therefore, C2H2 consumption could be attributed to ac
Authors
Laurence G. Miller, Shaun M. Baesman, Julie Kirshtein, Mary A. Voytek, Ronald S. Oremland
Strong nonlinear photonic responses from microbiologically synthesized tellurium nanocomposites
A new class of nanomaterials, namely microbiologically-formed nanorods composed of elemental tellurium [Te(0)] that forms unusual nanocomposites when combined with poly(m-phenylenevinylene-co-2,5-dioctoxy-phenylenevinylene) (PmPV) is described. These bio-nanocomposites exhibit excellent broadband optical limiting at 532 and 1064 nm. Nonlinear scattering, originating from the laser induced solvent
Authors
K.-S. Liao, Jingyuan Wang, S. Dias, J. Dewald, N.J. Alley, Shaun Baesman, Ronald S. Oremland, W.J. Blau, S.A. Curran
Enrichment and isolation of Bacillus beveridgei sp. nov., a facultative anaerobic haloalkaliphile from Mono Lake, California, that respires oxyanions of tellurium, selenium, and arsenic
Mono Lake sediment slurries incubated with lactate and tellurite [Te(IV)] turned progressively black with time because of the precipitation of elemental tellurium [Te(0)]. An enrichment culture was established from these slurries that demonstrated Te(IV)-dependent growth. The enrichment was purified by picking isolated black colonies from lactate/Te(IV) agar plates, followed by repeated streaking
Authors
S.M. Baesman, J.F. Stolz, T.R. Kulp, R.S. Oremland
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-Te-isotopi
Authors
Shaun M. Baesman, Thomas D. Bullen, J. Dewald, Donghui Zhang, S. Curran, F.S. Islam, T.J. Beveridge, Ronald S. Oremland
Laboratory determination of the carbon kinetic isotope effects (KIEs) for reactions of methyl halides with various nucleophiles in solution
Large carbon kinetic isotope effects (KIEs) were measured for reactions of methyl bromide (MeBr), methyl chloride (MeCl), and methyl iodide (MeI) with various nucleophiles at 287 and 306 K in aqueous solutions. Rates of reaction of MeBr and MeI with H2O (neutral hydrolysis) or Cl− (halide substitution) were consistent with previous measurements. Hydrolysis rates increased with increasing temperatu
Authors
S.M. Baesman, L.G. Miller
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
Bioreactors for removing methyl bromide following contained fumigations
Use of methyl bromide (MeBr) as a quarantine, commodity, or structural fumigant is under scrutiny because its release to the atmosphere contributes to the depletion of stratospheric ozone. A closed-system bioreactor consisting of 0.5 L of a growing culture of a previously described bacterium, strain IMB-1, removed MeBr (>110 μmol L-1) from recirculating air. Strain IMB-1 grew slowly to high cell d
Authors
Laurence G. Miller, Shaun Baesman, Ronald S. Oremland
Science and Products
- Publications
Detection of diazotrophy in the acetylene-fermenting anaerobe Pelobacter sp. strain SFB93
Acetylene (C2H2) is a trace constituent of the present Earth's oxidizing atmosphere, reflecting a mixture of terrestrial and marine emissions from anthropogenic, biomass-burning, and unidentified biogenic sources. Fermentation of acetylene was serendipitously discovered during C2H2 block assays of N2O reductase, and Pelobacter acetylenicus was shown to grow on C2H2 via acetylene hydratase (AH). AHAuthorsDenise M. Akob, Shaun Baesman, John M. Sutton, Janna L. Fierst, Adam Mumford, Yesha Shrestha, Amisha T. Poret-Peterson, Stacy C. Bennett, Darren S. Dunlap, Karl B. Haase, Ronald S. OremlandAcetylene fuels TCE reductive dechlorination by defined Dehalococcoides/Pelobacter consortia
Acetylene (C2H2) can be generated in contaminated groundwater sites as a consequence of chemical degradation of trichloroethene (TCE) by in situ minerals, and C2H2 is known to inhibit bacterial dechlorination. In this study, we show that while high C2H2 (1.3 mM) concentrations reversibly inhibit reductive dechlorination of TCE by Dehalococcoides mccartyi isolates as well as enrichment cultures conAuthorsXinwei Mao, Ronald S. Oremland, Tong Liu, Abigail A Landers, Shaun Baesman, Lisa Alvarez-CohenStable carbon isotope fractionation during bacterial acetylene fermentation: Potential for life detection in hydrocarbon-rich volatiles of icy planet(oid)s
We report the first study of stable carbon isotope fractionation during microbial fermentation of acetylene (C2H2) in sediments, sediment enrichments, and bacterial cultures. Kinetic isotope effects (KIEs) averaged 3.7 ± 0.5‰ for slurries prepared with sediment collected at an intertidal mudflat in San Francisco Bay and 2.7 ± 0.2‰ for a pure culture of Pelobacter sp. isolated from these sediments.AuthorsLaurence Miller, Shaun Baesman, Ron OremlandMethane oxidation and molecular characterization of methanotrophs from a former mercury mine impoundment
The Herman Pit, once a mercury mine, is an impoundment located in an active geothermal area. Its acidic waters are permeated by hundreds of gas seeps. One seep was sampled and found to be composed of mostly CO2 with some CH4 present. The δ13CH4 value suggested a complex origin for the methane: i.e., a thermogenic component plus a biological methanogenic portion. The relatively 12C-enriched CO2 sugAuthorsShaun Baesman, Laurence G. Miller, Jeremy H. Wei, Yirang Cho, Emily D. Matys, Roger E. Summons, Paula V. Welander, Ronald S. OremlandMethane oxidation linked to chlorite dismutation
We examined the potential for CH4 oxidation to be coupled with oxygen derived from the dissimilatory reduction of perchlorate, chlorate, or via chlorite (ClO−2) dismutation. Although dissimilatory reduction of ClO−4 and ClO−3 could be inferred from the accumulation of chloride ions either in spent media or in soil slurries prepared from exposed freshwater lake sediment, neither of these oxyanionsAuthorsLaurence G. Miller, Shaun M. Baesman, Charlotte I. Carlström, John D. Coates, Ronald S. OremlandA biogeochemical and genetic survey of acetylene fermentation by environmental samples and bacterial isolates
Anoxic samples (sediment and groundwater) from 13 chemically diverse field sites were assayed for their ability to consume acetylene (C2H2). Over incubation periods ranging from ˜ 10 to 80 days, selected samples from 7 of the 13 tested sites displayed significant C2H2 removal. No significant formation of ethylene was noted in these incubations; therefore, C2H2 consumption could be attributed to acAuthorsLaurence G. Miller, Shaun M. Baesman, Julie Kirshtein, Mary A. Voytek, Ronald S. OremlandStrong nonlinear photonic responses from microbiologically synthesized tellurium nanocomposites
A new class of nanomaterials, namely microbiologically-formed nanorods composed of elemental tellurium [Te(0)] that forms unusual nanocomposites when combined with poly(m-phenylenevinylene-co-2,5-dioctoxy-phenylenevinylene) (PmPV) is described. These bio-nanocomposites exhibit excellent broadband optical limiting at 532 and 1064 nm. Nonlinear scattering, originating from the laser induced solventAuthorsK.-S. Liao, Jingyuan Wang, S. Dias, J. Dewald, N.J. Alley, Shaun Baesman, Ronald S. Oremland, W.J. Blau, S.A. CurranEnrichment and isolation of Bacillus beveridgei sp. nov., a facultative anaerobic haloalkaliphile from Mono Lake, California, that respires oxyanions of tellurium, selenium, and arsenic
Mono Lake sediment slurries incubated with lactate and tellurite [Te(IV)] turned progressively black with time because of the precipitation of elemental tellurium [Te(0)]. An enrichment culture was established from these slurries that demonstrated Te(IV)-dependent growth. The enrichment was purified by picking isolated black colonies from lactate/Te(IV) agar plates, followed by repeated streakingAuthorsS.M. Baesman, J.F. Stolz, T.R. Kulp, R.S. OremlandFormation 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-Te-isotopiAuthorsShaun M. Baesman, Thomas D. Bullen, J. Dewald, Donghui Zhang, S. Curran, F.S. Islam, T.J. Beveridge, Ronald S. OremlandLaboratory determination of the carbon kinetic isotope effects (KIEs) for reactions of methyl halides with various nucleophiles in solution
Large carbon kinetic isotope effects (KIEs) were measured for reactions of methyl bromide (MeBr), methyl chloride (MeCl), and methyl iodide (MeI) with various nucleophiles at 287 and 306 K in aqueous solutions. Rates of reaction of MeBr and MeI with H2O (neutral hydrolysis) or Cl− (halide substitution) were consistent with previous measurements. Hydrolysis rates increased with increasing temperatuAuthorsS.M. Baesman, L.G. MillerDegradation 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 degrAuthorsL.G. Miller, K.L. Warner, S.M. Baesman, R.S. Oremland, I.R. McDonald, S. Radajewski, J.C. MurrellBioreactors for removing methyl bromide following contained fumigations
Use of methyl bromide (MeBr) as a quarantine, commodity, or structural fumigant is under scrutiny because its release to the atmosphere contributes to the depletion of stratospheric ozone. A closed-system bioreactor consisting of 0.5 L of a growing culture of a previously described bacterium, strain IMB-1, removed MeBr (>110 μmol L-1) from recirculating air. Strain IMB-1 grew slowly to high cell dAuthorsLaurence G. Miller, Shaun Baesman, Ronald S. Oremland