title: Kinetics of biodegradation of p-nitrobenzoate and inhibition by benzoate in a pseudomonad.
abstract: The degradation of p-nitrobenzoate (p-NBA) by domestic sewage was inhibited by benzoate, and a model for this behavior was found in a soil isolate. The isolate, a pseudomonad, utilized p-NBA and benzoate by separate adaptive enzyme pathways. In oxygen uptake experiments, the degradation of p-NBA was competitively inhibited by benzoate, but the degradation of benzoate was not affected by the presence of p-NBA. 4-Nitrocatechol was not implicated in the inhibition. p-Hydroxybenzoate, which is the p-NBA degradation pathway, also had a decreased rate od degradation when benzoate was present. The growth rate of the isolate on the aromatic substrates and on glucose autoclaved in the medium was 0.3 h-1. When glucose was autoclaved separately, the growth rate was less, about 0.2 h-1. The apparent Km in oxygen uptake experiments was 25 micrometer for p-NBA and benzoate and 5 micrometer for p-hydroxybenzoate.
mesh_terms: D001565:Benzoates / Q000378:metabolism*; D001673:Biodegradation, Environmental; D009579:Nitrobenzoates / Q000378:metabolism*; D010101:Oxygen Consumption; D011549:Pseudomonas / Q000378:metabolism*; D012722:Sewage; D012988:Soil Microbiology; D014871:Water Microbiology
chemical_list: D001565:Benzoates; D009579:Nitrobenzoates; D012722:Sewage