TRANSFORMATION OF CHRYSENE AND OTHER POLYCYCLIC AROMATIC HYDROCARBON MIXTURES BY THE FUNGUS CUNNINGHAMELLA-ELEGANS

Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous and persistent environmental pollutants; some are mutagenic, toxic, and carcinogenic and remain a public health concern. We investigated the metabolism of mixtures of PAHs and a tetracyclic aromatic hydrocarbon, chrysene, by the filamentous fungus, Cunninghamella elegans ATCC 36112. Cunninghame lla elegans metabolized a mixture of PAHs including the carcinogen ben zo[a]pyrene, phenanthrene, fluoranthene, pyrene, and acenaphthene comp letely to hydroxylated intermediates within 24 h. The metabolites from the PAH mixtures were similar to those formed in earlier studies of i ndividual PAH compounds. In separate experiments with chrysene, C. ele gans metabolized about 45% of the [5,6,11, 12-C-14]chrysene added to c ultures during 144 h incubation. The two major metabolites of chrysene were separated by reverse-phase high performance liquid chromatograph y and identified by ultraviolet-visible, mass spectral, and H-1-nuclea r magnetic resonance techniques as sulfate conjugates of 2,8-dihydroxy chrysene and 2-hydroxychrysene. The two major metabolites accounted fo r about 33% of the total metabolism. The formation of sulfate conjugat es of phenolic chrysene metabolites acid glucoside conjugates and hydr oxylated products of PAH mixtures by C, elagans may be a detoxificatio n step, because these types of products are generally less toxic than the parent compound.