Bioconversion of cereal straw into mushroom compost

Agaricus bisporus mushrooms are cultivated on straw compost prepared in the sequence phase I and phase II. Phase I is a process at 70–80 °C for several days up to 2 weeks. Phase II is a controlled process at 45 °C for 6 days. In phase II the thermophilic fungus Scytalidium thermophilum becomes abundant. Its density in finished compost is correlated with the yield of mushrooms. It stimulates the growth rate of mushroom mycelium. Scytalidium thermophilum was inoculated in batches of 1 tonne of pasteurized compost for experimental phase II. Mushroom yields on these composts were twice those of controls (pasteurized, not inoculated). This indicated that S. thermophilum is important for the conversion of straw to compost. The essential actions for mushroom crop productivity of high temperatures during phase I and of S. thermophilum during phase II are unclear.