Decolorization of Dark Brown Pigments in Molasses Wastewater by Mutant Strains of Aspergillus usamii and Coriolus versicolor

Abstract

The dark brown pigments contained in molasses wastewater (MW) are hardly decomposed by usual microorganisms. In light of this, Aspergillus usamiiandCoriolus versicolorwere selected for mutation induction by C⁵⁺ion-beams or γ-irradiation to increase their ability to decolorize these brown pigments. In this study, the decolorization yield from crude MW was 40 to 42% after 2-3 d incubation at 8-fold dilutions by mutant strains of A.usamiiwhich were obtained by ion-beam irradiation while it was 30% by the parent strain. In the case of C. versicolor, the decolorization yield was increased to ca. 70% by the mutant strains after 5 to 6 d incubation at 8-hold dilutions whereas the yield was 51% by the parent strain.