TITLE:
Sustainable Discoloration of Textile Chromo-Baths by Spent Mushroom Substrate from the Industrial Cultivation of Pleurotus ostreatus
AUTHORS:
Simona Di Gregorio, Francesco Balestri, Maria Basile, Valentina Matteini, Francesco Gini, Stefania Giansanti, Maria Grazia Tozzi, Riccardo Basosi, Roberto Lorenzi
KEYWORDS:
Anthraquinonic Dye, Diazo Dye, Laccase, Monoazo Dye, White Rot Fungi, Spent Mushroom Substrate
JOURNAL NAME:
Journal of Environmental Protection,
Vol.1 No.2,
June
29,
2010
ABSTRACT: 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.