Six fungal species were isolated from Egyptian soil and identified as Aspergillus flavus, Aspergillus niger, Penicillium canescens, Penicillium crustosum, Penicillium sp. and Fusarium sp. and were tested for their decolorization activity of direct blue dye (DB). Aspergillus flavus and Penicillium canescens were the best active fungal species for decolorization of direct blue dye. The optimum conditions for direct blue dye decolorization by both fungi grown on Czapeks Dox liquid medium were at a concentration of 0.01% Direct blue dye, sucrose as a carbon source, NaNO3 as a nitrogen source, incubation temperature 30°C and 35°C and pH 4, 5 for both fungi respectively and incubation time for 7 days. Addition of some metals (Ca, Ni, Co) to the growth medium exhibited little effect on dye decolorization. Whereas, Cu (2+) highly inhibited dye decolorization by both fungi.
Key words: Penicillium canescens, Direct Blue dye, Decolorization.
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