Factors limiting aliphatic chlorocarbon degradation by Nitrosomonas europaea: cometabolic inactivation of ammonia monooxygenase and substrate specificity

• Published in: Applied and Environmental Microbiology Vol. 57; no. 10; pp. 2986 - 2994
• Main Authors: RASCHE, M. E, HYMAN, M. R, ARP, D. J
• Format: Journal Article
• Language: English
• Published: Washington, DC American Society for Microbiology 01.10.1991
• Subjects: 560300 > Chemicals Metabolism & Toxicology; actividad enzimatica; activite enzymatique; AMMONIA; ammonia monooxygenase; ammoniac; amoniaco; Analytical, structural and metabolic biochemistry; BACTERIA; biodegradacion; BIODEGRADATION; Biological and medical sciences; CARBON 14 COMPOUNDS; CARBON COMPOUNDS; CHEMICAL REACTIONS; CHLORINATED ALIPHATIC HYDROCARBONS; DECOMPOSITION; ENVIRONMENTAL SCIENCES; enzimas; enzyme; ENZYME INHIBITORS; ENZYMES; Enzymes and enzyme inhibitors; enzymic activity; flora del suelo; flore du sol; Fundamental and applied biological sciences. Psychology; HALOGENATED ALIPHATIC HYDROCARBONS; halogenated hydrocarbons; hidrocarburos halogenados; HYDRIDES; hydrocarbure halogene; HYDROGEN COMPOUNDS; INACTIVATION; ISOTOPE APPLICATIONS; LABELLED COMPOUNDS; METABOLISM; MICROORGANISMS; NITROGEN COMPOUNDS; NITROGEN HYDRIDES; ORGANIC CHLORINE COMPOUNDS; ORGANIC COMPOUNDS; ORGANIC HALOGEN COMPOUNDS; OXIDOREDUCTASES; OXYGENASES; Physiology and Biotechnology; PROTEINS 540220 > Environment, Terrestrial > Chemicals Monitoring & Transport > (1990-); RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT; radioactive labelling; soil flora; SUBSTRATES; TOXICITY; TRACER TECHNIQUES; trichloroethylene; Biodegradation; Enzyme inhibitor; Bacteria; Nitrosomonas europaea; Metabolism; Nitrobacteraceae
• ISSN: 0099-2240; 1098-5336
• DOI: 10.1128/aem.57.10.2986-2994.1991

The son nitrifying bacterium Nitrosomonas europaea is capable of degrading trichloroethylene. (TCE) and other halogenated hydrocarbons. TCE cometabolism by N. europaea resulted in an irreversible loss of TCE biodegradative capacity, ammonia-oxidizing activity, and ammonia-dependent O2, uptake by the cells. inactivation was not observed in the presence of allylthiourea, a specific inhibitor of the enzyme ammonia monooxygenase, or under anaerobic conditions, indicating that the TCE-mediated inactivation required ammonia monooxygenase activity. When N. europaea cells were incubated with [14C]TCE under conditions which allowed turnover of ammonia monooxygenase, a number of cellular proteins were covalently labeled with 14C. Treatment of cells with allylthiourea or acetylene prior to incubation with [14C]TCE prevented incorporation of 14C into proteins. The ammonia-oxidizing activity of cells inactivated in the presence of TCE could be recovered through a process requiring de novo protein synthesis. In addition to TCE, a series of chlorinated methanes, ethanes, and other ethylenes were screened as substrates for ammonia monooxygenase and for their ability to inactivate the ammonia-oxidizing system of N. europaea. The chlorocarbons could be divided into three classes depending on their biodegradability and inactivating potential: (i) compounds which were not biodegradable by N. europaea and which had no toxic effect on the cells; (ii) compounds which were cooxidized by N. europaea and had little or no toxic effect on the cells; and (iii) compounds which were cooxidized and produced a turnover-dependent inactivation of ammonia oxidation by N. europaea.