Effects of physical properties of wood on the water activity of wood meal media for the cultivation of edible mushrooms

The effects of physical properties of wood, including specific gravity, porosity, and water retention, on the water activity (a(w)) of wood meal media for the cultivation of edible mushrooms were examined. Five species of wood, selected from an initial set of 11 species, and six species of fungi popularly cultivated in Japan were used. The water activity of each fungal species was measured using liquid media in which aw had been reduced by adding NaCl, KCl, sucrose, or ethylene glycol. From the water activities of the media and fungi, we estimated the most suitable wood species for the cultivation of each edible mushroom in wood meal media. Suitable wood species for the wood meal cultivation of shiitake, nameko, and maitake, which had relatively high a(w), was limited to hardwoods like arakashi, konara, and irohakaede because of their higher water activities. Edible mushrooms with lower levels of a,, like hiratake, enokitake, and bunashimeji, could be cultivated in all kinds of wood species used in this experiment, but especially in sugi.