Alexander J. B. Zehnder

Water scarcity, pricing mechanism and institutional reform in northern China irrigated agriculture (2003)

Yang, Hong, Zhang, Xiaohe James, Zehnder, Alexander J. B.

With water scarcity becoming an increasing constraint to food production in northern China, pricing mechanism has been given a high priority in dealing with the problem. Using selected irrigation...

Water scarcity, pricing mechanism and institutional reform in northern China irrigated agriculture (2003)

Yang, Hong, Zhang, Xiaohe James, Zehnder, Alexander J. B.

With water scarcity becoming an increasing constraint to food production in northern China, pricing mechanism has been given a high priority in dealing with the problem. Using selected irrigation...

Oekologie der Methanbakterien. (1976)

Zehnder, Alexander J.B.

Diss. Nr. 5716 Naturwiss. ETH Zürich, 1976 (KA).

Molecular Diversity of Plasmids Bearing Genes That Encode Toluene and Xylene Metabolism in Pseudomonas Strains Isolated from Different Contaminated Sites in Belarus

Sentchilo, Vladimir S., Perebituk, Alexander N., Zehnder, Alexander J. B., Van Der Meer, Jan Roelof

Twenty different Pseudomonas strains utilizing m-toluate were isolated from oil-contaminated soil samples near Minsk, Belarus. Seventeen of these isolates carried plasmids ranging in size from 78 to...

Bacterial Phosphating of Mild (Unalloyed) Steel

Volkland, Hans-Peter, Harms, Hauke, Müller, Beat, Repphun, Gernot, Wanner, Oskar, Zehnder, Alexander J. B.

Mild (unalloyed) steel electrodes were incubated in phosphate-buffered cultures of aerobic, biofilm-forming Rhodococcus sp. strain C125 and Pseudomonas putida mt2. A resulting surface reaction...

In Vitro ATP Regeneration from Polyphosphate and AMP by Polyphosphate:AMP Phosphotransferase and Adenylate Kinase from Acinetobacter johnsonii 210A

Resnick, Sol M., Zehnder, Alexander J. B.

In vitro enzyme-based ATP regeneration systems are important for improving yields of ATP-dependent enzymatic reactions for preparative organic synthesis and biocatalysis. Several enzymatic ATP...

Characterization of a Second tfd Gene Cluster for Chlorophenol and Chlorocatechol Metabolism on Plasmid pJP4 in Ralstonia eutropha JMP134(pJP4)

Laemmli, Caroline M., Leveau, Johan H. J., Zehnder, Alexander J. B., Van Der Meer, Jan Roelof

Within the 5.9-kb DNA region between the tfdR and tfdK genes on the 2,4-dichlorophenoxyacetic acid (2,4-D) catabolic plasmid pJP4 from Ralstonia eutropha JMP134, we identified five open reading...

Grazing of a Tetrahymena sp. on Adhered Bacteria in Percolated Columns Monitored by In Situ Hybridization with Fluorescent Oligonucleotide Probes

Eisenmann, Heinrich, Harms, Hauke, Meckenstock, Rainer, Meyer, Elisabeth I., Zehnder, Alexander J. B.

Predation of attached Pseudomonas putida mt2 by the small ciliate Tetrahymena sp. was investigated with a percolated column system. Grazing rates were examined under static and dynamic conditions and...

Low-Frequency Horizontal Transfer of an Element Containing the Chlorocatechol Degradation Genes from Pseudomonas sp. Strain B13 to Pseudomonas putida F1 and to Indigenous Bacteria in Laboratory-Scale Activated-Sludge Microcosms

Ravatn, Roald, Zehnder, Alexander J. B., Van Der Meer, Jan Roelof

The possibilities for low-frequency horizontal transfer of the self-transmissible chlorocatechol degradative genes (clc) from Pseudomonas sp. strain B13 were investigated in activated-sludge...

The tfdK Gene Product Facilitates Uptake of 2,4-Dichlorophenoxyacetate by Ralstonia eutropha JMP134(pJP4)

Leveau, Johan H. J., Zehnder, Alexander J. B., Van Der Meer, Jan Roelof

Uptake of 2,4-dichlorophenoxyacetate (2,4-D) by Ralstonia eutropha JMP134(pJP4) was studied and shown to be an energy-dependent process. The uptake system was inducible with 2,4-D and followed...

Enantioselective Uptake and Degradation of the Chiral Herbicide Dichlorprop [(RS)-2-(2,4-Dichlorophenoxy)propanoic acid] by Sphingomonas herbicidovorans MH

Zipper, Christian, Bunk, Monika, Zehnder, Alexander J. B., Kohler, Hans-Peter E.

Sphingomonas herbicidovorans MH was able to completely degrade both enantiomers of the chiral herbicide dichlorprop [(RS)-2-(2,4-dichlorophenoxy)propanoic acid], with preferential degradation of the...

Chromosomal Integration, Tandem Amplification, and Deamplification in Pseudomonas putida F1 of a 105-Kilobase Genetic Element Containing the Chlorocatechol Degradative Genes from Pseudomonas sp. Strain B13

Ravatn, Roald, Studer, Sonja, Springael, Dirk, Zehnder, Alexander J. B., Van Der Meer, Jan Roelof

Analysis of chlorobenzene-degrading transconjugants of Pseudomonas putida F1 which had acquired the genes for chlorocatechol degradation (clc) from Pseudomonas sp. strain B13 revealed that the clc...

Int-B13, an Unusual Site-Specific Recombinase of the Bacteriophage P4 Integrase Family, Is Responsible for Chromosomal Insertion of the 105-Kilobase clc Element of Pseudomonas sp. Strain B13

Ravatn, Roald, Studer, Sonja, Zehnder, Alexander J. B.

Pseudomonas sp. strain B13 carries the clcRABDE genes encoding chlorocatechol-degradative enzymes on the self-transmissible 105-kb clc element. The element integrates site and orientation...

The Global Regulatory hns Gene Negatively Affects Adhesion to Solid Surfaces by Anaerobically Grown Escherichia coli by Modulating Expression of Flagellar Genes and Lipopolysaccharide Production

Landini, Paolo, Zehnder, Alexander J. B.

The initial binding of bacterial cells to a solid surface is a critical and essential step in biofilm formation. In this report we show that stationary-phase cultures of Escherichia coli W3100 (a...

Evidence for the Existence of Psychrophilic Methanogenic Communities in Anoxic Sediments of Deep Lakes

Nozhevnikova, Alla N., Zepp, Kornelia, Vazquez, Francisco, Zehnder, Alexander J. B., Holliger, Christof

In order to obtain evidence for the existence of psychrophilic methanogenic communities in sediments of deep lakes that are low-temperature environments (4 to 5°C), slurries were first incubated at...

Community Analysis of Ammonia and Nitrite Oxidizers during Start-Up of Nitritation Reactors

Egli, Konrad, Langer, Christian, Siegrist, Hans-Ruedi, Zehnder, Alexander J. B., Wagner, Michael, Van Der Meer, Jan Roelof

Partial nitrification of ammonium to nitrite under oxic conditions (nitritation) is a critical process for the effective use of alternative nitrogen removal technologies from wastewater. Here we...

Bacterial Adhesion under Static and Dynamic Conditions

Rijnaarts, Huub H. M., Norde, Willem, Bouwer, Edward J., Lyklema, Johannes, Zehnder, Alexander J. B.

The deposition of various pseudomonads and coryneform bacteria with different hydrophobicities (water contact angles) and negative cell surface charges on negatively charged Teflon and glass surfaces...

Physicochemical Cell Surface and Adhesive Properties of Coryneform Bacteria Related to the Presence and Chain Length of Mycolic Acids

Bendinger, Bernd, Rijnaarts, Huub H. M., Altendorf, Karlheinz, Zehnder, Alexander J. B.

The presence and chain length of mycolic acids of bacteria of the genera Corynebacterium, Rhodococcus, Gordona, Mycobacterium, and Arthrobacter and of coryneform bacteria containing a type B...

Xylose and Glucose Utilization by Bacteroides xylanolyticus X5-1 Cells Grown in Batch and Continuous Culture

Biesterveld, Steef, Zehnder, Alexander J. B., Stams, Alfons J. M.

During cultivation on a mixture of xylose and glucose, Bacteroides xylanolyticus X5-1 showed neither diauxic growth nor a substrate preference. Xylose-limited continuous-culture cells were able to...

Regulation of Product Formation in Bacteroides xylanolyticus X5-1 by Interspecies Electron Transfer

Biesterveld, Steven, Zehnder, Alexander J. B., Stams, Alfons J. M.

Bacteroides xylanolyticus X5-1 was grown in pure culture and in mixed culture with Methanospirillum hungatei JF-1 under xylose limitation in the chemostat. In the pure culture, ethanol, acetate, CO2,...

Role of Cations in Accumulation and Release of Phosphate by Acinetobacter Strain 210A

Van Groenestijn, Johan W., Anink, Désirée M. E., Deinema, Maria H., Zehnder, Alexander J. B.

Cells of the strictly aerobic Acinetobacter strain 210A, containing aerobically large amounts of polyphosphate (100 mg of phosphorus per g [dry weight] of biomass), released in the absence of oxygen...

Kinetics of Sulfate and Acetate Uptake by Desulfobacter postgatei

Ingvorsen, Kjeld, Zehnder, Alexander J. B., Jørgensen, Bo B.

The kinetics of sulfate and acetate uptake was studied in the sulfate-reducing bacterium Desulfobacter postgatei (DSM 2034). Kinetic parameters (Km and Vmax) were estimated from substrate consumption...

Methanogenesis in an Upflow Anaerobic Sludge Blanket Reactor at pH 6 on an Acetate-Propionate Mixture

Ten Brummeler, Erik, Pol, Look W. Hulshoff, Dolfing, Jan, Lettinga, Gatze, Zehnder, Alexander J. B.

High-rate anaerobic digestion can be applied in upflow anaerobic sludge blanket reactors for the treatment of various wastewaters. In upflow anaerobic sludge blanket reactors, sludge retention time...

Pathways of Propionate Degradation by Enriched Methanogenic Cultures

Koch, Markus, Dolfing, Jan, Wuhrmann, Karl, Zehnder, Alexander J. B.

A mixed methanogenic culture was highly enriched in a growth medium containing propionate as the sole organic carbon and energy source. With this culture, the pathways of propionate degradation were...

Measuring Radioactive Methane with the Liquid Scintillation Counter

Zehnder, Alexander J. B., Huser, Beat, Brock, Thomas D.

Although a gas proportional counter is the most convenient method of measuring the radioactivity of fixed gases such as methane, it cannot be used when high nonradioactive concentrations of methane...

Anaerobic Oxidation of Acetylene by Estuarine Sediments and Enrichment Cultures

Culbertson, Charles W., Zehnder, Alexander J. B., Oremland, Ronald S.

Acetylene disappeared from the gas phase of anaerobically incubated estuarine sediment slurries, and loss was accompanied by increased levels of carbon dioxide. Acetylene loss was inhibited by...

Anaerobic Methane Oxidation: Occurrence and Ecology

Zehnder, Alexander J. B., Brock, Thomas D.

Anoxic sediments and digested sewage sludge anaerobically oxidized methane to carbon dioxide while producing methane. This strictly anaerobic process showed a temperature optimum between 25 and...

Molecular Diversity of Plasmids Bearing Genes That Encode Toluene and Xylene Metabolism in Pseudomonas Strains Isolated from Different Contaminated Sites in Belarus

Sentchilo, Vladimir S., Perebituk, Alexander N., Zehnder, Alexander J. B., Van Der Meer, Jan Roelof

Twenty different Pseudomonas strains utilizing m-toluate were isolated from oil-contaminated soil samples near Minsk, Belarus. Seventeen of these isolates carried plasmids ranging in size from 78 to...

Bacterial Phosphating of Mild (Unalloyed) Steel

Volkland, Hans-Peter, Harms, Hauke, Müller, Beat, Repphun, Gernot, Wanner, Oskar, Zehnder, Alexander J. B.

Mild (unalloyed) steel electrodes were incubated in phosphate-buffered cultures of aerobic, biofilm-forming Rhodococcus sp. strain C125 and Pseudomonas putida mt2. A resulting surface reaction...

In Vitro ATP Regeneration from Polyphosphate and AMP by Polyphosphate:AMP Phosphotransferase and Adenylate Kinase from Acinetobacter johnsonii 210A

Resnick, Sol M., Zehnder, Alexander J. B.

In vitro enzyme-based ATP regeneration systems are important for improving yields of ATP-dependent enzymatic reactions for preparative organic synthesis and biocatalysis. Several enzymatic ATP...

Characterization of a Second tfd Gene Cluster for Chlorophenol and Chlorocatechol Metabolism on Plasmid pJP4 in Ralstonia eutropha JMP134(pJP4)

Laemmli, Caroline M., Leveau, Johan H. J., Zehnder, Alexander J. B., Van Der Meer, Jan Roelof

Within the 5.9-kb DNA region between the tfdR and tfdK genes on the 2,4-dichlorophenoxyacetic acid (2,4-D) catabolic plasmid pJP4 from Ralstonia eutropha JMP134, we identified five open reading...

Grazing of a Tetrahymena sp. on Adhered Bacteria in Percolated Columns Monitored by In Situ Hybridization with Fluorescent Oligonucleotide Probes

Eisenmann, Heinrich, Harms, Hauke, Meckenstock, Rainer, Meyer, Elisabeth I., Zehnder, Alexander J. B.

Predation of attached Pseudomonas putida mt2 by the small ciliate Tetrahymena sp. was investigated with a percolated column system. Grazing rates were examined under static and dynamic conditions and...

Low-Frequency Horizontal Transfer of an Element Containing the Chlorocatechol Degradation Genes from Pseudomonas sp. Strain B13 to Pseudomonas putida F1 and to Indigenous Bacteria in Laboratory-Scale Activated-Sludge Microcosms

Ravatn, Roald, Zehnder, Alexander J. B., Van Der Meer, Jan Roelof

The possibilities for low-frequency horizontal transfer of the self-transmissible chlorocatechol degradative genes (clc) from Pseudomonas sp. strain B13 were investigated in activated-sludge...

The tfdK Gene Product Facilitates Uptake of 2,4-Dichlorophenoxyacetate by Ralstonia eutropha JMP134(pJP4)

Leveau, Johan H. J., Zehnder, Alexander J. B., Van Der Meer, Jan Roelof

Uptake of 2,4-dichlorophenoxyacetate (2,4-D) by Ralstonia eutropha JMP134(pJP4) was studied and shown to be an energy-dependent process. The uptake system was inducible with 2,4-D and followed...

Enantioselective Uptake and Degradation of the Chiral Herbicide Dichlorprop [(RS)-2-(2,4-Dichlorophenoxy)propanoic acid] by Sphingomonas herbicidovorans MH

Zipper, Christian, Bunk, Monika, Zehnder, Alexander J. B., Kohler, Hans-Peter E.

Sphingomonas herbicidovorans MH was able to completely degrade both enantiomers of the chiral herbicide dichlorprop [(RS)-2-(2,4-dichlorophenoxy)propanoic acid], with preferential degradation of the...

Chromosomal Integration, Tandem Amplification, and Deamplification in Pseudomonas putida F1 of a 105-Kilobase Genetic Element Containing the Chlorocatechol Degradative Genes from Pseudomonas sp. Strain B13

Ravatn, Roald, Studer, Sonja, Springael, Dirk, Zehnder, Alexander J. B., Van Der Meer, Jan Roelof

Analysis of chlorobenzene-degrading transconjugants of Pseudomonas putida F1 which had acquired the genes for chlorocatechol degradation (clc) from Pseudomonas sp. strain B13 revealed that the clc...

Int-B13, an Unusual Site-Specific Recombinase of the Bacteriophage P4 Integrase Family, Is Responsible for Chromosomal Insertion of the 105-Kilobase clc Element of Pseudomonas sp. Strain B13

Ravatn, Roald, Studer, Sonja, Zehnder, Alexander J. B.

Pseudomonas sp. strain B13 carries the clcRABDE genes encoding chlorocatechol-degradative enzymes on the self-transmissible 105-kb clc element. The element integrates site and orientation...

The Global Regulatory hns Gene Negatively Affects Adhesion to Solid Surfaces by Anaerobically Grown Escherichia coli by Modulating Expression of Flagellar Genes and Lipopolysaccharide Production

Landini, Paolo, Zehnder, Alexander J. B.

The initial binding of bacterial cells to a solid surface is a critical and essential step in biofilm formation. In this report we show that stationary-phase cultures of Escherichia coli W3100 (a...

Evidence for the Existence of Psychrophilic Methanogenic Communities in Anoxic Sediments of Deep Lakes

Nozhevnikova, Alla N., Zepp, Kornelia, Vazquez, Francisco, Zehnder, Alexander J. B., Holliger, Christof

In order to obtain evidence for the existence of psychrophilic methanogenic communities in sediments of deep lakes that are low-temperature environments (4 to 5°C), slurries were first incubated at...

Community Analysis of Ammonia and Nitrite Oxidizers during Start-Up of Nitritation Reactors

Egli, Konrad, Langer, Christian, Siegrist, Hans-Ruedi, Zehnder, Alexander J. B., Wagner, Michael, Van Der Meer, Jan Roelof

Partial nitrification of ammonium to nitrite under oxic conditions (nitritation) is a critical process for the effective use of alternative nitrogen removal technologies from wastewater. Here we...

Bacterial Adhesion under Static and Dynamic Conditions

Rijnaarts, Huub H. M., Norde, Willem, Bouwer, Edward J., Lyklema, Johannes, Zehnder, Alexander J. B.

The deposition of various pseudomonads and coryneform bacteria with different hydrophobicities (water contact angles) and negative cell surface charges on negatively charged Teflon and glass surfaces...

Physicochemical Cell Surface and Adhesive Properties of Coryneform Bacteria Related to the Presence and Chain Length of Mycolic Acids

Bendinger, Bernd, Rijnaarts, Huub H. M., Altendorf, Karlheinz, Zehnder, Alexander J. B.

The presence and chain length of mycolic acids of bacteria of the genera Corynebacterium, Rhodococcus, Gordona, Mycobacterium, and Arthrobacter and of coryneform bacteria containing a type B...

Xylose and Glucose Utilization by Bacteroides xylanolyticus X5-1 Cells Grown in Batch and Continuous Culture

Biesterveld, Steef, Zehnder, Alexander J. B., Stams, Alfons J. M.

During cultivation on a mixture of xylose and glucose, Bacteroides xylanolyticus X5-1 showed neither diauxic growth nor a substrate preference. Xylose-limited continuous-culture cells were able to...

Regulation of Product Formation in Bacteroides xylanolyticus X5-1 by Interspecies Electron Transfer

Biesterveld, Steven, Zehnder, Alexander J. B., Stams, Alfons J. M.

Bacteroides xylanolyticus X5-1 was grown in pure culture and in mixed culture with Methanospirillum hungatei JF-1 under xylose limitation in the chemostat. In the pure culture, ethanol, acetate, CO2,...

Role of Cations in Accumulation and Release of Phosphate by Acinetobacter Strain 210A

Van Groenestijn, Johan W., Anink, Désirée M. E., Deinema, Maria H., Zehnder, Alexander J. B.

Cells of the strictly aerobic Acinetobacter strain 210A, containing aerobically large amounts of polyphosphate (100 mg of phosphorus per g [dry weight] of biomass), released in the absence of oxygen...

Kinetics of Sulfate and Acetate Uptake by Desulfobacter postgatei

Ingvorsen, Kjeld, Zehnder, Alexander J. B., Jørgensen, Bo B.

The kinetics of sulfate and acetate uptake was studied in the sulfate-reducing bacterium Desulfobacter postgatei (DSM 2034). Kinetic parameters (Km and Vmax) were estimated from substrate consumption...

Methanogenesis in an Upflow Anaerobic Sludge Blanket Reactor at pH 6 on an Acetate-Propionate Mixture

Ten Brummeler, Erik, Pol, Look W. Hulshoff, Dolfing, Jan, Lettinga, Gatze, Zehnder, Alexander J. B.

High-rate anaerobic digestion can be applied in upflow anaerobic sludge blanket reactors for the treatment of various wastewaters. In upflow anaerobic sludge blanket reactors, sludge retention time...

Pathways of Propionate Degradation by Enriched Methanogenic Cultures

Koch, Markus, Dolfing, Jan, Wuhrmann, Karl, Zehnder, Alexander J. B.

A mixed methanogenic culture was highly enriched in a growth medium containing propionate as the sole organic carbon and energy source. With this culture, the pathways of propionate degradation were...

Measuring Radioactive Methane with the Liquid Scintillation Counter

Zehnder, Alexander J. B., Huser, Beat, Brock, Thomas D.

Although a gas proportional counter is the most convenient method of measuring the radioactivity of fixed gases such as methane, it cannot be used when high nonradioactive concentrations of methane...

Anaerobic Oxidation of Acetylene by Estuarine Sediments and Enrichment Cultures

Culbertson, Charles W., Zehnder, Alexander J. B., Oremland, Ronald S.

Acetylene disappeared from the gas phase of anaerobically incubated estuarine sediment slurries, and loss was accompanied by increased levels of carbon dioxide. Acetylene loss was inhibited by...

Anaerobic Methane Oxidation: Occurrence and Ecology

Zehnder, Alexander J. B., Brock, Thomas D.

Anoxic sediments and digested sewage sludge anaerobically oxidized methane to carbon dioxide while producing methane. This strictly anaerobic process showed a temperature optimum between 25 and...