Disposal of agro-industrial by-products by organic cultivation of the culinary and medicinal mushroom Hypsizygus marmoreus

Organic mushroom cultivation is one of the fastest growing segments of agriculture. At the core of the organic philosophy lies a ban on the use of synthetic fertilizers, pesticides and herbicides, in addition to such tenets as animal welfare, energy efficiency, and social justice. Hypsizygus marmoreus (HM) is a highly praised cultivated culinary and medicinal mushroom. The objective of this paper was to assess the suitability of different spawn media and then the potential of various cultivation substrates to support HM mushroom production compatible with organic standards. This objective was met through the setup of a low-cost cultivation infrastructure. First, seven types of spawn media were tested; then we tested 24 substrates made from organic by-products for their biological efficiency (BE) with strain HM 830, using the liquid inoculation method. The best substrate in terms of BE was corn cob with bran and olive press cake, with a BE of 85.6%. The BE of the same composition but without olive press cake was only 67.5%. The next best substrates were cotton straw combinations with a BE of 31.5-53%. The spent mushroom substrate provides a good method for the disposal of solid waste. The guidance provided in this research complies with organic mushroom cultivation standards and can be used to produce certified organic mushrooms. In addition, it allows responsible and beneficial disposal of a large amount of solid agro-industrial waste.