Quantitative immunologic analysis of the methanogenic flora of digestors reveals a considerable diversity.
(1/5)
To determine which methanogens occur in digestors, we performed a quantitative immunologic analysis of a variety of samples. A comprehensive panel of calibrated polyclonal antibody probes of predefined specificity spectra was used. This allowed precise identification of bacteria by antigenic fingerprinting. A considerable diversity of methanogens was uncovered, much larger than previously reported, encompassing at least 14 strains of 11 species. Strategies were developed to measure the load of any given methanogen in a sample and to compare samples quantitatively. Two methanogens were found to predominate which were antigenically closely related with either Methanobacterium formicicum MF or Methanobrevibacter arboriphilus AZ. Fundamental data, probes, and methods are now available to monitor methanogenic subpopulations during digestor operation and thus learn about their respective roles and predictive significance. (+info)
Direct characterization of methanogens in two high-rate anaerobic biological reactors.
(2/5)
The methanogenic flora from two types of turbulent, high-rate reactors was studied by immunologic methods as well as by phase-contrast, fluorescence, and scanning electron microscopy. The reactors were a fluidized sand-bed biofilm ANITRON reactor and an ultrafiltration membrane-associated suspended growth MARS reactor (both trademarks of Air Products and Chemicals, Inc., Allentown, Pa.). Conventional microscopic methods revealed complex mixtures of microbes of a range of sizes and shapes, among which morphotypes resembling Methanothrix spp. and Methanosarcina spp. were noticed. Precise identification of these and other methanogens was accomplished by antigenic fingerprinting with a comprehensive panel of calibrated antibody probes of predefined specificity spectra. The methanogens identified showed morphotypes and antigenic fingerprints indicating their close similarity with the following reference organisms: Methanobacterium formicicum MF and Methanosarcina barkeri W in the ANITRON reactor only; Methanosarcina barkeri R1M3, M. mazei S6, Methanogenium cariaci JR1, and Methanobrevibacter arboriphilus AZ in the MARS reactor only; and Methanobrevibacter smithii ALI and Methanothrix soehngenii Opfikon in both reactors. Species diversity and distribution appeared to be, at least in part, dependent on the degree of turbulence inside the reactor. (+info)
Isolation and characterization of methanogenic bacteria from landfills.
(3/5)
Methanogenic bacteria were isolated from landfill sites in the United Kingdom. Strains of Methanobacterium formicicum, Methanosarcina barkeri, several different immunotypes of Methanobacterium bryantii, and a coccoid methanogen distinct from the reference immunotypes were identified. (+info)
Shifts in methanogenic subpopulations measured with antibody probes in a fixed-bed loop anaerobic bioreactor treating sulfite evaporator condensate.
(4/5)
A fixed-bed loop, high-rate anaerobic bioreactor treating sulfite evaporator condensate was sampled when it reached steady state and afterwards following perturbations during a 14-month period. By using immunotechnology, it was observed that shifts in methanogenic subpopulations occurred in association with perturbations, such as restarting and relocating the biomass into a different tank. Methanogens related to Methanobacterium bryantii MoHG and Methanobrevibacter smithii ALI were numerous throughout the observation period, while Methanosarcina mazei S6 and Methanosarcina thermophila TM1 were found in the early and late samples, respectively. Also, Methanobacterium formicicum was more numerous at the top portion of the bioreactor, while Methanobrevibacter arboriphilus AZ and DC were at the bottom. Sample formalinization required for prolonged storage proved suitable for antigen preservation. (+info)
Diversity and population dynamics of methanogenic bacteria in a granular consortium.
(5/5)
Upflow anaerobic sludge blanket bioreactor granules were used as an experimental model microbial consortium to study the dynamics and distribution of methanogens. Immunologic methods revealed a considerable diversity of methanogens that was greater in mesophilic granules than in the same granules 4 months after a temperature shift from 38 to 55 degrees C. During this period, the sizes of the methanogenic subpopulations changed with distinctive profiles after the initial reduction caused by the shift. Methanogens antigenically related to Methanobrevibacter smithii PS and ALI, Methanobacterium hungatei JF1, and Methanosarcina thermophila TM1 increased rapidly, reached a short plateau, and then fell to lower concentrations that persisted for the duration of the experiment. A methanogen related to Methanogenium cariaci JR1 followed a similar profile at the beginning, but it soon diminished below detection levels. Methanothrix rods weakly related to the strain Opfikon increased rapidly, reaching a high-level, long-lasting plateau. Two methanogens related to Methanobrevibacter arboriphilus AZ and Methanobacterium thermoautotrophicum DeltaH emerged from very low levels before the temperature shift and multiplied to attain their highest numbers 4 months after the shift. Histochemistry and immunohistochemistry revealed thick layers, globular clusters, and lawns of variable density which were distinctive of the methanogens related to M. thermoautotrophicum DeltaH, M. thermophila TM1, and M. arboriphilus AZ and M. soehngenii Opfikon, respectively, in thin sections of granules grown at 55 degrees C for 4 months. Mesophilic granules showed a different pattern of methanogenic subpopulations. (+info)