Removal of triphenylmethane dyes in single-dye and dye-metal mixtures by live and dead cells of metal-tolerant Penicillium simplicissimum

In the absence of various metal ions, live cells of Penicillium simplicissimum decolorized Crystal Violet (CV), Methyl Violet (MV), Malachite Green (MG) and Cotton Blue (CB) (75.6-90.8%, 0.5-2 h) more efficiently than dead cells (43.9-75.2%, 4 h). Cu(II) enhanced CB removal by live and dead cells (64.1-82.0%) but with Cd(II), Zn(II) and Cr(III), removal of CV, MV and MG were inhibited. Pb(II) inhibited dye removal by live cells (63.1-78.1%), while dead cells remained unaffected (40.6-74.0%). Dye removal was attributed to binding to hydroxyl, carbonyl, amino, phosphoryl and nitro groups based on FTIR analyses. Dye-metal-fungi interactions revealed new binding sites and non-involvement of specific functional groups that previously interacted with single dyes. Hence, this study indicated that isolate 10 (especially live cells) is capable of removing dyes from dye-metal solutions.