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Dimethylsulfoniopropionate as a potential methanogenic substrate in Mono Lake sediments
A high concentration of dimethylsulfoniopropionate (DMSP) was found in the water column (0.1–1.8 µM particulate plus dissolved) of Mono Lake, CA, an alkaline, hypersaline waterbody. The dense Artemia monica population contained high levels of DMSP (1.7–2.5 mmol.g-1 wet weight), presumably as an osmolyte. Death of these brine shrimp caused accumulation of DMSP along the shoreline of the lake, where
Microbial cycling of methyl bromide
Environmental concern about brominated halocarbons like methyl bromide (MeBr) is focused on their potential to destroy stratospheric ozone. Photocatalysis of MeBr and other halocarbons in the stratosphere results in the liberation of reactive CI and Br atoms. Because Br atoms are perhaps as much as 100-fold more efficient at attacking ozone than are CI atoms, bromine’s lower abundance is partly co
Methanolobus taylorii sp nov, a new methylotropic, estuarine methanogen
Strain GS-16T (T = type strain) is a methylotrophic methanogen that was isolated from estuarine sediments from San Francisco Bay (4) and has been deposited in the Oregon Collection of Methanogens (Oregon Graduate Institute, Portland) as strain OCM 5ST. This strain was isolated by using dimethyl sulfide as the catabolic substrate (4), but it can also grow on methylamines (13) and methanethiol (8, 9
Isolation, growth, and metabolism of an obligately anaerobic, selenate- respiring bacterium, strain SES-3
A gram-negative, strictly anaerobic, motile vibrio was isolated from a selenate-respiring enrichment culture. The isolate, designated strain SES-3, grew by coupling the oxidation of lactate to acetate plus CO2 with the concomitant reduction of selenate to selenite or of nitrate to ammonium. No growth was observed on sulfate or selenite, but cell suspensions readily reduced selenite to elemental se
Aspects of the biogeochemistry of methane in Mono Lake and the Mono Basin of California
Above-ambient levels of methane and higher hydrocarbons were detected in the atmosphere of the Mono Basin. These gases emanated from several different sources, including natural gas seeps (thermogenic and biogenic), and methanogenic activity in sediments. Seeps were distributed over nearly 33% of the lake bottom and were also present in the exposed former lakebed. They originated from one or more
Meromixis in hypersaline Mono Lake, California. 3. Biogeochemical response to stratification and overturn
Mono Lake is a terminal, saline lake that became ectogenically meromictic in 1982–1983 and remained stratified until November 1988. During this period, the monimolimnion remained anoxic and nearly isothermal, while the upper mixolimnion was well oxygenated and exhibited a seasonal thermal regime. Dissolved sulfide and methane increased in the monimolimnion as a result of diffusive flux from the se
Evaluation of methyl fluoride and dimethyl ether as inhibitors of aerobic methane oxidation
Methyl fluoride (MF) and dimethyl ether (DME) were effective inhibitors of aerobic methanotrophy in a variety of soils. MF and DME blocked consumption of CH4 as well as the oxidation of 14CH4 to 14CO2, but neither MF nor DME affected the oxidation of [14C]methanol or [14C]formate to 14CO2. Cooxidation of ethane and propane by methane-oxidizing soils was also inhibited by MF. Nitrification (ammonia
Nitrate is a preferred electron acceptor for growth of freshwater selenate-respiring bacteria
An anaerobic, freshwater enrichment grew with either nitrate or selenate as an electron acceptor. With both ions present, nitrate reduction preceded selenate reduction. An isolate from the enrichment grew on either ion, but the presence of nitrate precluded the reduction of selenate. Stock cultures of denitrifiers grew anaerobically on nitrate but not on selenate.
Importance of methane-oxidizing bacteria in the methane budget as revealed by the use of a specific inhibitor
METHANE is a greenhouse gas whose concentration in the atmosphere is increasing. Much of this methane is derived from the metabolism of methane-generating (methanogenic) bacteria and over the past two decades much has been learned about the ecology of methanogens; specific inhibitors of methanogenesis, such as 2-bromoethanesulphonic acid, have proved useful in this regard. In contrast, although mu
Measurement of in situ rates of selenate removal by dissimilatory bacterial reduction in sediments
A radioisotope method for measurement of bacteria respiratory reduction of selenate to elemental selenium in aquatic sediments was devised. Sediments were labeled with [75Se]selenate, incubated, and washed, and 75Se0(s) was determined as counts remaining in the sediments. Core profiles of selenate reduction, sulfate reduction, and denitrification were made simultaneously in the sediments of an agr
Selenate reduction to elemental selenium by anaerobic bacteria in sediments and culture: Biogeochemical significance of a novel, sulfate-independent respiration
Interstitial water profiles of SeO42−, SeO32−, SO42−, and Cl− in anoxic sediments indicated removal of the seleno-oxyanions by a near-surface process unrelated to sulfate reduction. In sediment slurry experiments, a complete reductive removal of SeO42− occurred under anaerobic conditions, was more rapid with H2 or acetate, and was inhibited by O2, NO3−, MnO2, or autoclaving but not by SO42− or FeO
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Filter Total Items: 115
Dimethylsulfoniopropionate as a potential methanogenic substrate in Mono Lake sediments
A high concentration of dimethylsulfoniopropionate (DMSP) was found in the water column (0.1–1.8 µM particulate plus dissolved) of Mono Lake, CA, an alkaline, hypersaline waterbody. The dense Artemia monica population contained high levels of DMSP (1.7–2.5 mmol.g-1 wet weight), presumably as an osmolyte. Death of these brine shrimp caused accumulation of DMSP along the shoreline of the lake, whereMicrobial cycling of methyl bromide
Environmental concern about brominated halocarbons like methyl bromide (MeBr) is focused on their potential to destroy stratospheric ozone. Photocatalysis of MeBr and other halocarbons in the stratosphere results in the liberation of reactive CI and Br atoms. Because Br atoms are perhaps as much as 100-fold more efficient at attacking ozone than are CI atoms, bromine’s lower abundance is partly coMethanolobus taylorii sp nov, a new methylotropic, estuarine methanogen
Strain GS-16T (T = type strain) is a methylotrophic methanogen that was isolated from estuarine sediments from San Francisco Bay (4) and has been deposited in the Oregon Collection of Methanogens (Oregon Graduate Institute, Portland) as strain OCM 5ST. This strain was isolated by using dimethyl sulfide as the catabolic substrate (4), but it can also grow on methylamines (13) and methanethiol (8, 9Isolation, growth, and metabolism of an obligately anaerobic, selenate- respiring bacterium, strain SES-3
A gram-negative, strictly anaerobic, motile vibrio was isolated from a selenate-respiring enrichment culture. The isolate, designated strain SES-3, grew by coupling the oxidation of lactate to acetate plus CO2 with the concomitant reduction of selenate to selenite or of nitrate to ammonium. No growth was observed on sulfate or selenite, but cell suspensions readily reduced selenite to elemental seAspects of the biogeochemistry of methane in Mono Lake and the Mono Basin of California
Above-ambient levels of methane and higher hydrocarbons were detected in the atmosphere of the Mono Basin. These gases emanated from several different sources, including natural gas seeps (thermogenic and biogenic), and methanogenic activity in sediments. Seeps were distributed over nearly 33% of the lake bottom and were also present in the exposed former lakebed. They originated from one or moreMeromixis in hypersaline Mono Lake, California. 3. Biogeochemical response to stratification and overturn
Mono Lake is a terminal, saline lake that became ectogenically meromictic in 1982–1983 and remained stratified until November 1988. During this period, the monimolimnion remained anoxic and nearly isothermal, while the upper mixolimnion was well oxygenated and exhibited a seasonal thermal regime. Dissolved sulfide and methane increased in the monimolimnion as a result of diffusive flux from the seEvaluation of methyl fluoride and dimethyl ether as inhibitors of aerobic methane oxidation
Methyl fluoride (MF) and dimethyl ether (DME) were effective inhibitors of aerobic methanotrophy in a variety of soils. MF and DME blocked consumption of CH4 as well as the oxidation of 14CH4 to 14CO2, but neither MF nor DME affected the oxidation of [14C]methanol or [14C]formate to 14CO2. Cooxidation of ethane and propane by methane-oxidizing soils was also inhibited by MF. Nitrification (ammoniaNitrate is a preferred electron acceptor for growth of freshwater selenate-respiring bacteria
An anaerobic, freshwater enrichment grew with either nitrate or selenate as an electron acceptor. With both ions present, nitrate reduction preceded selenate reduction. An isolate from the enrichment grew on either ion, but the presence of nitrate precluded the reduction of selenate. Stock cultures of denitrifiers grew anaerobically on nitrate but not on selenate.Importance of methane-oxidizing bacteria in the methane budget as revealed by the use of a specific inhibitor
METHANE is a greenhouse gas whose concentration in the atmosphere is increasing. Much of this methane is derived from the metabolism of methane-generating (methanogenic) bacteria and over the past two decades much has been learned about the ecology of methanogens; specific inhibitors of methanogenesis, such as 2-bromoethanesulphonic acid, have proved useful in this regard. In contrast, although muMeasurement of in situ rates of selenate removal by dissimilatory bacterial reduction in sediments
A radioisotope method for measurement of bacteria respiratory reduction of selenate to elemental selenium in aquatic sediments was devised. Sediments were labeled with [75Se]selenate, incubated, and washed, and 75Se0(s) was determined as counts remaining in the sediments. Core profiles of selenate reduction, sulfate reduction, and denitrification were made simultaneously in the sediments of an agrSelenate reduction to elemental selenium by anaerobic bacteria in sediments and culture: Biogeochemical significance of a novel, sulfate-independent respiration
Interstitial water profiles of SeO42−, SeO32−, SO42−, and Cl− in anoxic sediments indicated removal of the seleno-oxyanions by a near-surface process unrelated to sulfate reduction. In sediment slurry experiments, a complete reductive removal of SeO42− occurred under anaerobic conditions, was more rapid with H2 or acetate, and was inhibited by O2, NO3−, MnO2, or autoclaving but not by SO42− or FeO