Author(s)

Simona Di Gregorio, Francesco Balestri, Maria Basile, Valentina Matteini, Francesco Gini, Stefania Giansanti, Maria Grazia Tozzi, Riccardo Basosi, Roberto Lorenzi

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Synthetic dyes are recalcitrant to degradation and toxic to different organisms. Physical-chemical treatments of textile wastewaters are not sustainable in terms of costs. Biological treatments can be more convenient and the lig-nin-degrading extracellular enzymatic battery of basidiomycetes are capable to discolor synthetic dyes. Many basidi-omycetes are edible mushrooms whose industrial production generates significant amount of spent mushroom substrate (SMS) with residual high levels of lignin-degrading extracellular enzymatic activities. We have demon-strated that the low cost organic substrate, the SMS deriving from the cultivation of the basidiomycetes Pleurotus ostreatus, is able to discolor anthraquinonic, diazo and monoazo-dyes when incubated in dying chromo-reactive and chromo-acid baths containing surfactants and anti-foams, where the concentrations of the different dyes are exceeding the one recovered in the corresponding wastewaters. Laccase was the lignin-degrading extracellular enzyme involved in the discolouring process. The exploitation of the low cost SMS in the treatment of textile wastewaters is proposed. Accordingly, a toxicological assessment, based on a cyto-toxicity test on a human amnion epithelial cell line (WISH) and the estimation of the germination index (GI%) of Lactuca sativa, Cucumis sativus and Sorghum bicolor, has been performed, showing the loss of toxicity of the chromo-baths after being discoloured by the SMS.

Anthraquinonic Dye, Diazo Dye, Laccase, Monoazo Dye, White Rot Fungi, Spent Mushroom Substrate

S. Gregorio, F. Balestri, M. Basile, V. Matteini, F. Gini, S. Giansanti, M. Tozzi, R. Basosi and R. Lorenzi, "Sustainable Discoloration of Textile Chromo-Baths by Spent Mushroom Substrate from the Industrial Cultivation of Pleurotus ostreatus," Journal of Environmental Protection, Vol. 1 No. 2, 2010, pp. 85-94. doi: 10.4236/jep.2010.12011.