title: Diversity and population dynamics of methanogenic bacteria in a granular consortium.
abstract: 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.
authors.affiliation: Department of Microbiology and Department of Environmental Technology and Wadsworth Center for Laboratories and Research, New York State Department of Health, State University of New York at Albany, Albany, New York 12201-0509.
authors.forename: F A
authors.initials: FA
authors.lastname: Visser
authors.forename: J B
authors.initials: JB
authors.lastname: van Lier
authors.forename: A J
authors.initials: AJ
authors.lastname: Macario
authors.forename: E
authors.initials: E
authors.lastname: Conway de Macario
mesh_terms: D019844:Antibodies, Archaeal / Q000378:metabolism; D019845:Antigens, Archaeal / Q000032:analysis; D044822:Biodiversity; D019149:Bioreactors / Q000382:microbiology*; D015169:Colony Count, Microbial; D019605:Euryarchaeota / Q000502:physiology*; D012722:Sewage / Q000382:microbiology*
chemical_list: D019844:Antibodies, Archaeal; D019845:Antigens, Archaeal; D012722:Sewage