Sustainable and Eco-Friendly Conversions of Olive Mill Wastewater-Based Media by Pleurotus pulmonarius Cultures

Abstract

Pleurotus pulmonarius mushroom was cultivated on liquid cultures with olive mill wastewaters (OMWs) of initial phenolic compound concentrations of 0 (control), 1, 2 and 3 g/L and glucose at initial concentrations of 40 and 60 g/L. The ability of the fungus to grow on media containing toxic compounds enriched with glucose was assessed through biomass production, glucose consumption, polysaccharide (IPS) accumulation and total cellular lipids biosynthesis, while the total phenolic compounds (TPC) and antioxidant component monitoring were also assessed during a 43-day fermentation. An analysis of the total simple sugar composition of IPS and the total fatty acid composition of lipids was performed. The phenolic reduction and media decolorization were also monitored. Results showed that the addition of glucose in OMW-based media had a positive effect on biomass, IPS and lipid production and increased the unsaturated fatty acids and TPC concentration. The maximum recorded values were the following: biomass 32.76 g/L, IPS 4.38 g/L (14.70%, w/w in dry weight), lipids 2.85 g/L (11.69%, w/w in dry weight). The mycelial lipids were unsaturated and dominated by linoleic acid, whereas IPS were composed mainly of glucose. Significant phenolic compound reduction (87–95%) and color removal (70–85%) occurred. Results strongly suggest the potentiality of P. pulmonarius utilization in the OMW treatment.