Cultivation of Pleurotus spp., as an Alternative Solution to Dispose Olive Waste

Disposal of olive press cake (OPC) produced during olive oil production is an important problem in Mediterranean Basin. The objective of this paper is to investigate effectively removing OPC by production of Pleurotus spp. In the study, four substrate formulations containing variable OPC concentration were tested for cultivation of Pleurotus spp and determined effect of these substrates on productivity of P. djamor, P. eryngii and P. citrinopileatus species. Zero (0%), 25%, 50% and 75% portions of OPC were added to beech sawdust to prepare the growing substrates. It was observed that different portions of OPC affect spawn run time (day), time to first primordia initiation (day), time to first harvest (day), yield (g/kg) and biological efficiency (BE) of Pleurotus spp. No negative effect on mycelial growth of the three Pleurotus spp. was observed in any substrates during the spawn running period, but high concentration of OPC had a negative effect on earliness. On the other hand, 25 OPC and 50 OPC substrates showed higher biological efficiencies than the control substrate in all Pleurotus spp. Morever, the highest yield and BE were obtained in P. djamor grown on 75 OPC substrate. This study demostrated that high portions of OPC are promising as a substrate for P. djamor, P. citrinopileatus and P. eryngii cultivation and using OPC as a substrate in mushroom cultivation provides an eco-friendly method for disposing of OPC.