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Multi‐stage chemostat investigation of interspecies interactions in a hexanoate‐catabolizing microbial association isolated from anoxic landfill

Author:
Coutts, D. A. P., Senior, E., Balba, M. T. M.
Source:
Journal of applied microbiology 1987 v.62 no.3 pp. 251-260
ISSN:
1364-5072
Subject:
carbon dioxide, electrons, habitats, interspecific competition, landfills, metabolism, methane production, methanogens, models, oxidation
Abstract:
Spatial separations of physico‐chemical environments (habitat domains) with maintenance of overlapping zones of influence (activity domains) with multi‐stage chemostat models were used to facilitate examination of interspecies interactions within a hexanoate‐catabolizing microbial association isolated from anoxic landfill. Under a constant dilution rate regime, in the presence of 1.4 and 5 mmol/l influent sulphate, consolidation of the major metabolic events of hexanoate catabolism, sulphate reduction, acetogenesis and methanogenesis took place in the first vessel of a five‐vessel array suggesting considerable overlap of activity domains or localization around the habitat domains. Evidence of partial competitive displacement was not apparent until 10 mmol/l of sulphate was used. Introduction of a non‐constant dilution rate regime to a three‐vessel model, subjected to an influent sulphate concentration of 1.4 mmol/l, effected the displacement of the methanogenic species and, as a consequence, in the presence of sulphate limitation, CO2 reduction became the major sink for excess electrons generated from hexanoate oxidation. A hypothetical scheme of anaerobic hexanoate catabolism by the interacting microbial association was developed.
Agid:
137531