Abstract
The effects of water content in substrate on the degree of maturity and yields of fruiting body of Sugi sawdust bed were investigated using shiitake fungus. Effects of lignin addition to the medium on the yield of fruiting body were also examined. The colonization period was longer in Sugi sawdust bed than in Konara sawdust bed. In Sugi sawdust bed, however, the period decreased with the increase in water content. The brinell hardness on the surface of Konara sawdust bed increased with the increase in incubation period. On the other hand, the hardness on the surface of Sugi sawdust bed gradually increased up to 40 days of incubation, whereas it gradually decreased thereafter. The results obtained suggest that brinell hardness can be used as an indicator for evaluating the maturity degree of sawdust bed. The lignin addition to the sugi sawdust bed remarkably promoted the yields of shiitake fruiting body, although little yield of fruiting body was obtained in Sugi sawdust bed without lignin addition. These results suggest that certain compounds derived from degraded lignin are involved in shiitake fruiting body formation.
