Kinetics of Butyrate, Acetate, and Hydrogen Metabolism in a Thermophilic, Anaerobic, Butyrate-Degrading Triculture

Kinetics of butyrate, acetate, and hydrogen metabolism were determined with butyrate-limited, chemostat-grown tricultures of a thermophilic butyrate-utilizing bacterium together with Methanobacterium thermoautotrophicum and the TAM organism, a thermophilic acetate-utilizing methanogenic rod. Kinetic parameters were determined from progress curves fitted to the integrated form of the Michaelis-Menten equation. The apparent half-saturation constants, Km, for butyrate, acetate, and dissolved hydrogen were 76 μM, 0.4 mM, and 8.5 μM, respectively. Butyrate and hydrogen were metabolized to a concentration of less than 1 μM, whereas acetate uptake usually ceased at a concentration of 25 to 75 μM, indicating a threshold level for acetate uptake. No significant differences in Km values for butyrate degradation were found between chemostat- and batch-grown tricultures, although the maximum growth rate was somewhat higher in the batch cultures in which the medium was supplemented with yeast extract. Acetate utilization was found to be the rate-limiting reaction for complete degradation of butyrate to methane and carbon dioxide in continuous culture. Increasing the dilution rate resulted in a gradual accumulation of acetate. The results explain the low concentrations of butyrate and hydrogen normally found during anaerobic digestion and the observation that acetate is the first volatile fatty acid to accumulate upon a decrease in retention time or increase in organic loading of a digestor.

[1]  Stephen H. Zinder,et al.  Isolation and Characterization of a Thermophilic Strain of Methanosarcina Unable to Use H2-CO2 for Methanogenesis , 1979, Applied and environmental microbiology.

[2]  J. Robinson,et al.  Method for measuring dissolved hydrogen in anaerobic ecosystems: application to the rumen , 1981, Applied and environmental microbiology.

[3]  M. P. Bryant,et al.  Growth of Desulfovibrio in Lactate or Ethanol Media Low in Sulfate in Association with H2-Utilizing Methanogenic Bacteria , 1977, Applied and environmental microbiology.

[4]  R. Mah,et al.  Growth and Methanogenesis by Methanosarcina Strain 227 on Acetate and Methanol , 1978, Applied and Environmental Microbiology.

[5]  J. A. Robinson,et al.  Kinetics of Hydrogen Consumption by Rumen Fluid, Anaerobic Digestor Sludge, and Sediment , 1982, Applied and environmental microbiology.

[6]  M. P. Bryant,et al.  Commentary on the Hungate technique for culture of anaerobic bacteria. , 1972, The American journal of clinical nutrition.

[7]  B. Ahring,et al.  Isolation and characterization of a thermophilic, acetate-utilizing methanogenic bacterium , 1984 .

[8]  J. Tiedje,et al.  Kinetic Parameters of the Conversion of Methane Precursors to Methane in a Hypereutrophic Lake Sediment , 1978, Applied and environmental microbiology.

[9]  Birgitte K. Ahring,et al.  Thermophilic Anaerobic Degradation of Butyrate by a Butyrate-Utilizing Bacterium in Coculture and Triculture with Methanogenic Bacteria , 1987, Applied and environmental microbiology.

[10]  R S Wolfe,et al.  New approach to the cultivation of methanogenic bacteria: 2-mercaptoethanesulfonic acid (HS-CoM)-dependent growth of Methanobacterium ruminantium in a pressureized atmosphere , 1976, Applied and environmental microbiology.

[11]  K. Wuhrmann,et al.  Kinetic parameters and relative turnovers of some important catabolic reactions in digesting sludge , 1978, Applied and environmental microbiology.

[12]  B. Ahring,et al.  Methanogenesis from acetate: Physiology of a thermophilic, acetate-utilizing methanogenic bacterium , 1985 .

[13]  M. P. Bryant,et al.  Metabolic Activity of Fatty Acid-Oxidizing Bacteria and the Contribution of Acetate, Propionate, Butyrate, and CO2 to Methanogenesis in Cattle Waste at 40 and 60°C , 1981, Applied and environmental microbiology.

[14]  T. J. Phelps,et al.  Gas Metabolism Evidence in Support of the Juxtaposition of Hydrogen-Producing and Methanogenic Bacteria in Sewage Sludge and Lake Sediments , 1985, Applied and environmental microbiology.

[15]  J. Tiedje,et al.  Isolation and Partial Characterization of Bacteria in an Anaerobic Consortium That Mineralizes 3-Chlorobenzoic Acid , 1984, Applied and environmental microbiology.

[16]  R. J. Hall,et al.  Kinetics of two subgroups of propionate-using organisms in anaerobic digestion , 1983, Applied and environmental microbiology.

[17]  L. Dijkhuizen,et al.  Strategies of mixed substrate utilization in microorganisms. , 1982, Philosophical transactions of the Royal Society of London. Series B, Biological sciences.

[18]  R. E. Hungate,et al.  The anaerobic mesophilic cellulolytic bacteria. , 1950, Bacteriological reviews.

[19]  S. Zinder,et al.  Isolation and Characterization of a Thermophilic Strain of Methanosarcina Unable to Use H(2)-CO(2) for Methanogenesis. , 1979, Applied and environmental microbiology.

[20]  M. P. Bryant,et al.  Syntrophomonas wolfei gen. nov. sp. nov., an Anaerobic, Syntrophic, Fatty Acid-Oxidizing Bacterium , 1981, Applied and environmental microbiology.

[21]  M. P. Bryant,et al.  Anaerobic Degradation of Lactate by Syntrophic Associations of Methanosarcina barkeri and Desulfovibrio Species and Effect of H2 on Acetate Degradation , 1981, Applied and environmental microbiology.

[22]  J. Henson,et al.  Isolation of a Butyrate-Utilizing Bacterium in Coculture with Methanobacterium thermoautotrophicum from a Thermophilic Digester , 1985, Applied and environmental microbiology.

[23]  Marvin P. Bryant,et al.  Microbial Methane Production—Theoretical Aspects , 1979 .

[24]  M. P. Bryant,et al.  Propionate-Degrading Bacterium, Syntrophobacter wolinii sp. nov. gen. nov., from Methanogenic Ecosystems , 1980, Applied and environmental microbiology.

[25]  F. A. Tomei,et al.  Interactions in Syntrophic Associations of Endospore-Forming, Butyrate-Degrading Bacteria and H2-Consuming Bacteria , 1985, Applied and environmental microbiology.