Discoloration of textile dyes by spent mushroom substrate of Agaricus bisporus

The textile industry discharges up to 5 % of their dyes in aqueous effluents. Here, use of spent mushroom substrate (SMS) of commercial white button mushroom production and its aqueous extract, SMS tea, was assessed to remove textile dyes from water. A total of 30–90 % and 5–85 % of the dyes was removed after a 24 h incubation in SMS and SMS tea, respectively. Removal of malachite green and remazol brilliant blue R was similar in SMS and its tea. In contrast, removal of crystal violet, orange G, and rose bengal was higher in SMS, explained by sorption to SMS and by the role of non-water-extractable SMS components in discoloration. Heat-treating SMS and its tea, thereby inactivating enzymes, reduced dye removal to 8–58 % and 0–31 %, respectively, indicating that dyes are removed by both enzymatic and non-enzymatic activities. Together, SMS of white button mushroom production has high potential to treat textile-dye-polluted aqueous effluents.</p

Enzymatic and non-enzymatic removal of organic micropollutants with spent mushroom substrate of Agaricus bisporus

Water bodies are increasingly contaminated with a diversity of organic micropollutants (OMPs). This impacts the quality of ecosystems due to their recalcitrant nature. In this study, we assessed the removal of OMPs by spent mushroom substrate (SMS) of the white button mushroom (Agaricus bisporus) and by its aqueous tea extract. Removal of acesulfame K, antipyrine, bentazon, caffeine, carbamazepine, chloridazon, clofibric acid, and N, N-diethyl-meta-toluamide (DEET) by SMS and its tea was between 10 and 90% and 0–26%, respectively, in a 7-day period. Sorption to SMS particles was between 0 and 29%, which can thus not explain the removal difference between SMS and its tea, the latter lacking these particles. Carbamazepine was removed most efficiently by both SMS and its tea. Removal of OMPs (except caffeine) by SMS tea was not affected by heat treatment. By contrast, heat-treatment of SMS reduced OMP removal to &lt; 10% except for carbamazepine with a removal of 90%. These results indicate that OMP removal by SMS and its tea is mediated by both enzymatic and non-enzymatic activities. The presence of copper, manganese, and iron (0.03, 0.88, and 0.33 µg L -1, respectively) as well as H 2O 2 (1.5 µM) in SMS tea indicated that the Fenton reaction represents (part of) the non-enzymatic activity. Indeed, the in vitro reconstituted Fenton reaction removed OMPs &gt; 50% better than the teas. From these data it is concluded that spent mushroom substrate of the white button mushroom, which is widely available as a waste-stream, can be used to purify water from OMPs.</p

Waste treating waste: Organic micropollutant removal from water by Agaricus bisporus spent mushroom substrate

The continual increase in domestic and industrial wastewater poses a significant challenge, as conventional wastewater treatment methods struggle to effectively remove persistent organic micropollutants (OMPs). OMPs, including pharmaceuticals, personal care products (PPCPs), and pesticides, persist in treated water, posing risks to human health and ecosystems. Current water quality in Europe is compromised by the prevalence of OMPs. While various technologies exist for OMP removal, they often entail high costs and carbon footprints. This study explores the potential of bioremediation, particularly using wood and litter-degrading fungi (WLDF), such as Agaricus bisporus, as a sustainable and cost-effective solution. A. bisporus, commonly known as the champignon mushroom, is a prolific WLDF. The mushroom's substrate, a waste product after harvest, is rich in lignin-modifying enzymes (LMEs) that have demonstrated OMP removal capabilities. LMEs, including lignin peroxidase (LiP), manganese peroxidase (MnP), versatile peroxidase (VP), and laccase (Lcc), are essential in mineralizing lignin. This study investigates whether A. bisporus spent mushroom substrate (SMS) can be utilized for OMP removal from water and aims to elucidate the underlying mechanisms. Research indicates that A. bisporus SMS and its tea exhibit substantial OMP removal capabilities. They effectively remove a variety of dyes, PPCPs, pesticides, and even industrial compounds like per- and polyfluoroalkyl substances (PFAS). This study reports, for the first time, the removal of PFAS using SMS and its tea. Furthermore, other WLDF, such as Pleurotus ostreatus and Trametes versicolor, also show potential for OMP removal. Mechanisms of OMP removal by A. bisporus involve both enzymatic and non-enzymatic processes. LMEs play a crucial role, but non-enzymatic activities, such as the Fenton reaction, also contribute to OMP removal. The study suggests that a combination of these mechanisms is responsible for the observed effectiveness in OMP removal. Interestingly, SMS outperforms its tea in OMP removal, indicating the importance of solid particles and potential stabilization of enzymes on these particles. Heat treatment of SMS and its tea highlights both enzymatic (heat-dependent) and non-enzymatic (heat-independent) activities contributing to OMP removal. The presence of metal ions and hydrogen peroxide supports the hypothesis that the Fenton reaction is involved in the process. Individual LMEs, when overexpressed in Schizophyllum commune, exhibit enhanced removal of specific OMPs. However, the study suggests that multiple enzymes and non-enzymatic activities collectively contribute to OMP removal, emphasizing the need for further research into enzyme combinations and interactions. In conclusion, A. bisporus SMS emerges as a sustainable and effective solution for OMP removal from water. The study lays the foundation for developing eco-friendly water purification technologies that mitigate the environmental impact of OMPs and contribute to improved water quality

A screening method for decoloration of xenobiotic dyes by fungi

Wood degrading fungi are often screened for their ability to degrade xenobiotics such as dyes. Dye decoloration by these fungi on solid media could until now only be assessed qualitatively. We here describe a fast quantitative method to screen for dye decoloration on such media. Decoloration of crystal violet (CV), malachite green (MG), orange G (OG), rose bengal (RB) and remazol brilliant blue R (RBBR) by 124 isolates of the basidiomycete Schizophyllum commune was quantified with a flatbed scanner and the CIE-L*a*b* model. Colour and intensity changes were calculated with the Euclidean distance formula. More than 10 strains showed high MG decoloration. Isolates 136, 140 and 213 showed superior CV decoloration, while OG was most effectively decolorized by isolates 183, 216 and 227. Six strains showed high RB decoloration with isolate 216 being superior. The latter strain was also highly active on RBBR together with isolates 177 and 227. Together, dye decoloration was highly variable between the 124 isolates but strain 216 showed high activity on 3 out of 5 dyes. The fast screening method described in this paper enables identification of strains effectively decolorizing dyes

A screening method for decoloration of xenobiotic dyes by fungi

Wood degrading fungi are often screened for their ability to degrade xenobiotics such as dyes. Dye decoloration by these fungi on solid media could until now only be assessed qualitatively. We here describe a fast quantitative method to screen for dye decoloration on such media. Decoloration of crystal violet (CV), malachite green (MG), orange G (OG), rose bengal (RB) and remazol brilliant blue R (RBBR) by 124 isolates of the basidiomycete Schizophyllum commune was quantified with a flatbed scanner and the CIE-L*a*b* model. Colour and intensity changes were calculated with the Euclidean distance formula. More than 10 strains showed high MG decoloration. Isolates 136, 140 and 213 showed superior CV decoloration, while OG was most effectively decolorized by isolates 183, 216 and 227. Six strains showed high RB decoloration with isolate 216 being superior. The latter strain was also highly active on RBBR together with isolates 177 and 227. Together, dye decoloration was highly variable between the 124 isolates but strain 216 showed high activity on 3 out of 5 dyes. The fast screening method described in this paper enables identification of strains effectively decolorizing dyes