Superfund Research Program
P450 Systems and Microbial Biodegradation
Project Summary (1995-2000)The goal of this research is to develop and characterize microbes and microbial systems capable of detoxifying environmentally recalcitrant hazardous chemicals. The project's focus is upon P450 gene systems of environmental yeasts and filamentous fungi which are known to use such systems in the metabolism of toxic pollutants. P450 metabolites of these pollutants are made either during degradation of the compound as a carbon source, as occurs with petroleum alkanes for some of these organisms, or as products of detoxication. Cunninghamella elegans is an attractive organism for the molecular characterization of detoxifying P450 systems. It was the first filamentous fungus shown to carry out P450 reactions and has since been demonstrated to express a wide range of P450 degradative activity in vivo, including monooxygenation of benzo[a]pyrene and similar multi-ring compounds. Study of P450 genes from halotolerant yeasts such as Debaryomyces hansenii may be useful in developing yeast-mediated transformation of mixtures of aliphatic and aromatic pollutants in toxic waste sites. Isolation of P450 genes from fungi known to metabolize environmental toxicants will lead to new levels of understanding of the P450 genes and their expression and how this knowledge can be put to practical use for public health.