Malachite green decolorization by non-basidiomycete filamentous fungi of Penicillium pinophilum and Myrothecium roridum

Fourteen of non-basidiomycete fungi isolated from biota contaminated with xenobiotics were investigated for their ability to decolorize a synthetic dye Malachite green (MG) during the growth on solid as well as in liquid Czapek-Dox (CzD) medium. Two strains of the highest efficiency of MG removal were identified by molecular techniques as Penicillium pinophilum and Myrothecium roridum and chosen for the more detailed study. Decolorization experiments accompanied by enzymes (laccase and MG reductase) assay and mycelium microscopic observations allow to propose patterns of MG removal by P. pinophilum and M. roridum. Strain of P. pinophilum decolorized MG by simultaneous biosorption with intracellular dye biotransformation accompanied by the 3-times increase activity of MG reductase. Removal of MG by M. roridum seemed to be mostly resulted from extracellular laccase activity (which was over 6 times higher in cells exposed to dye as compared to control mycelium). LC/MS/MS analyses of the intermediate compounds produced during decolorization of MG suggested that in both fungi biodegradation of MG involved reduction to leucomalachite green and conversion to N-demethylated metabolites.

► Malachite green (MG) removal by two newly isolated non-basidiomycte fungi.
► Identification of strains as Penicillium pinophilum and Myrothecium roridum.
► Induction of intracellular MG reductase during dye removal by P. pinophilum.
► Induction of extracellular laccase during dye decolorization by M. roridum.
► MG reduction to leucomalachite green and conversion to N-demethylated metabolites.