Abstract
Effects of adding polysaccharide-degrading enzymes to the substrate during medium preparation on the fruiting body formation of Hericium erinaceus and Pholiota microspora were evaluated by the free glucose and a- and b-glucan content in the medium. The fruiting body yield of H. erinaceus was 1.4 times higher after addition of an amylase, mesophilic amylase (MPA) or heat-resistant amylase (HRA), than the control. After addition of b-1,3-glucanase (GLU), the fruiting body yield of H. erinaceus was similarly 1.5 times higher than the control, while a mixture of HRA and GLU (HRA+GLU) did not show any additional effect. In the case of P. microspora, yields of fruiting body were 10－20% higher after addition of MPA or HRA from 50 ppm to 500 ppm to the substrate than in the control without enzyme. Moreover, the weight of each fruiting body was also higher in medium containing MPA or HRA. Although the addition of GLU had no effect, higher fruiting body yield was observed after the addition of HRA+GLU than HRA alone, suggesting a complementary effect of the enzyme mixture. The content of free glucose and low molecular weight a- and b-glucan were all increased by the addition of MPA or HRA in both H. erinaceus and P. microspora cultures. In P. microspora, however, there was no change in glucose or a- or b-glucan after GLU addition, while the addition of GLU had a similar effect to the addition of amylase in the H. erinaceus culture. These results reflect well the yield of fruiting bodies of both mushrooms. The addition of polysaccharide-degrading enzymes during medium preparation is an effective way to increase fruiting body yield if the appropriate combination of mushroom and enzymes is carefully evaluated.
