Combined action of a bacterial monooxygenase and a fungal laccase for the biodegradation of mono- and poly-aromatic hydrocarbons

The combined action of a wide substrate range toluene o-xylene monooxygenase from Pseudomonas sp. OX I, able to convert many aromatic compounds into mono- and di-hydroxylated derivatives, and fungal laccases from Pleurotus ostreatus which oxidize these hydroxylated products yielding polymers with reduced toxicity is described. This strategy permits to overcome many of the substrate specificity problems and dead end toxic products formation generally encountered in complex bacterial biodegradation pathways. Toluene and naphthalene degradations were tested as representative of mono- and poly-aromatic pollutants. The combined biological action was optimized in micellar and microemulsion systems able to increase the bioavailability of the hydrophobic aromatic pollutants. This approach allows efficient hydroxylations of hydrophobic substrates thus favoring the further action of fungal oxidases. (c) 2008 Elsevier Ltd, All rights reserved.