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

Abstract

ABSTRACT 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.