Production parameters and nutritional value of Pleurotus ostreatus mushroom cultivated on agricultural wastes

The influence of two alternative agro-residues (barley and oat straw-ΒΟ and beech wood residues-ΒW) used as main cultivation substrates in respect to wheat straw-WS was examined on the production and quality characteristics of Pleurotus ostreatus, strain AMRL 144. Evaluation included fungal bio-transformation efficiency with respect to substrate colonization and carposome production time, biological efficiency-BE%, as well as mushroom number, size, colour and firmness. The effect of these wastes was also evaluated on moisture content, crude protein, total polysaccharides, lipid and phenolic content of whole sporophores. First mushrooms appeared 19-42 days after inoculation, with WS and BOS substrates promoting earlier sporophore initiation than BW did. As for BE%, the highest values were recorded at BOS and BW wastes (75.30% and 64.26% respectively) compared to the conventional WS. Mushroom protein content was significantly increased when BW was used (28.25% versus 11.02 in WS) and so did colour lightness in BOS (L*=78.16). Firmer mushrooms were also produced in BOS and BW substrates (7.25 N) than in WS (6.56 N), while polysaccharides were synthesised in high amount, mostly in mushrooms cultivated in BW (35.47%) and consisted mainly of glucose (in higher than 70.5% w/w). Phenolic synthesis was promoted in BO and BW (640 mg/l GAE) versus WS (400 mg/l GAE) substrates. Mushroom lipid content, on the contrary, was not affected by the substrate used.