Decolourisation of mushroom farm wastewater by Pleurotus ostreatus

Abstract

Mushroom production on coffee pulp as substrate generates an intense black residual liquid, which requires suitable treatment. In the present study, Pleurotus ostreatus growth in wastewater from mushroom farm was evaluated as a potential biological treatment process for decolourisation as well as to obtain biomass (liquid inoculum). Culture medium components affecting mycelial growth were determined, evaluating colour removal. Laccase activity was monitored during the process. P. ostreatus was able to grow in non diluted WCP. Highest biomass yield was obtained when glucose (10 g/l) was added. The addition of this carbon source was necessary for efficient decolourisation. Agitation of the culture improved biodegradation of WCP as well as fungal biomass production. Laccase and manganese-independent peroxidase activities were detected during fungal treatment of the WCP by P. ostreatus CCEBI 3024. The laccase enzyme showed good correlation with colour loss. Both wastewater colour and pollution load (as chemical oxygen demand) decreased more than 50% after 10 days of culture. Phenols were reduced by 92%.

Sustainable Discoloration of Textile Chromo-Baths by Spent Mushroom Substrate from the Industrial Cultivation of Pleurotus ostreatus

“…Ligninolytic basidiomycetes causing white rot on wood, were shown to be the most promising fungi because of their capacity to produce a complex array of lignin-degrading extra-cellular enzymes, with very low substrate specificity towards xenobiotics [9]. The ligninolytic battery of extracellular enzymes of the basidiomycetes P. ostreatus has been described as capable to transform a very broad spectrum of waste substrates [14][15][16] including textile dyes [17]. However, it is worth to mention that P. ostreatus and many other basidiomycetes are edible mushrooms and their industrial cultivation produces a significant amount of spent mushroom substrate (SMS), reported as harboring high levels of residual oxidative enzymatic activity [18].…”

Mycoremediation of PCBs by Pleurotus ostreatus: Possibilities and Prospects

“…The process of PCB biodegradation mediated by fungi is also well established. Fungi's capacity to transform several PCB congeners in liquid medium have been described [18][19][20][21][22][23][24][25][26][27][28][29][30][31][32][33][34][35][36]. A few studies established the successful fungal transformation capacity in soils [18][19][20][21][22][23][24].…”

“…P. ostreatus produces ligninolytic enzymes which are able to interact with a plethora of waste substrates [33][34][35], including PCBs [36]. This mushroom's industrial cultivation faces a problem: the huge turnover of spent mushroom substrate (SMS), a lignocellulosic matrix, that has to be disposed of [56].…”

“…Myco-augmentation of contaminated matrices by this fungus is operational via substrate-unspecific extracellular and intracellular oxido reductases, laccases, and Mn-dependent and -independent peroxidases [28][29][30], enabling them to transform PCBs [24]. Additionally, P. ostreatus produces ligninolytic enzymes, which is an added asset, whereby it orchestrates the transformation of a plethora of waste substrates [31][32][33] including PCBs [34][35][36]. The exact mechanism whereby P. ostreatus degrades PCB is not worked out, but with the rich reservoirs of enzymes such as Lignin Peroxidases, managanese peroxidases, and laccases, there is no doubt that these enzymes will play a synergistic role, if not for individual contributions (Figure 1).…”

Immobilization of Mycelial Pellets from Liquid Spawn of Oyster Mushroom Based on Carrier Adsorption

“…The results showed that immobilized spawn on the basis of the mycelial pellets of liquid spawn adsorbed in carrier can be used to extend the storage time and simplify transportation of liquid spawn of edible mushroom. O yster mushroom is one of the most widely cultivated edible mushrooms in the world (Chang, 1999); it is also used in medicine (El-Fakharany et al, 2010;Gern et al, 2008), environmental remediation (Rodríguez Pérez et al, 2008;Yan et al, 2009), and biofuel (Okamura-Matsui et al, 2003). Like most other edible mushrooms, its spawn for cultivation is in solid state, which is composed of manure-grass, sawdust, wood block, branch wood, and grain.…”