Leftover bread as a substrate for Pleurotus ostreatus cultivation

Many different leftover materials have been used as substrates for mushroom cultivation in the past decades, solving problems with their deposition, their negative impact on the environment, reducing price of the substrates and some of them even raising quality and quantity of harvested fruiting bodies. Leftover bread as being one of those materials has, as far as we are aware, never been tested before as an ingredient of mushroom cultivation substrate. 12.000 to 15.000 tons of leftover bread is dumped each year in Slovenia alone, representing a burden for bakery industry and a negative effect on the environment. In this research leftover bread showed to be an appropriate supplement for wood based substrate used for P. ostreatus fruiting bodies cultivation, resulting in 63 % biological efficiency. In comparison to wheat bran and crushed corn seed containing substrates P. ostreatus fruiting bodies yields were higher on substrates composed of leftover bread, sawdust and CaCO3. Using leftover bread for mushroom cultivation could be an appropriate solution for its problematic deposition, resulting in solving financial problems of its producers, negative impact on the environment and in substrate price reduction.