Recycling of the waste bed logs used in the Shiitake cultivation into the resource of sawdust material for the cultivation of the commercial strain of Pleurotus ostreatus and the wild strain of Flammulina velutipes was examined. The yield of fruit bodies on the substrate using the saw dust from the waste bed logs was slightly lower than on the substrate using the sawdust from Abies sachalinensis Mast, which is a usual sawdust material in the Hokkaido area, in Japan, but it showed was almost equivalent productivity as compared with that of Quercus mongolica var. grosseserrata Rehd. et Wils.. However, the days required for fruiting initiation and for the harvest of the former substrate from waste bed logs were significantly shorter than on the latter sawdust substrate. These results suggest that the sawdust from the waste bed logs could be used as the resource for the cultivation of P. ostreatus and F. velutipes.

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Erythritol is the only sugar alcohol which can be used as non-calorie sweetener among food materials. The used-erythritol-producing -yeast (UEPY), a by-product in erythritol production, was examined as a supplement for Pleurotus ostreatus cultivation. It was shown that: 1. When UEPY was substituted with 25%〜75% of rice bran in dry weight basis, fruit body yields increased 27%〜44 % as compared with that in the medium using with a single use of rice bran. 2. In the case that only UEPY was used as a replacement of rice bran as only nutrient component, the mycelia of P. ostreatus could grow, but fruiting did not occur. 3. The supply of additional N and C sources, the amounts of which were calculated from the difference in the contents between UEPY and rice bran media, could not increase the fruit body yield with UEPY. 4. When K, Mg or P was added into the UEPY media, fruit bodies appeared. It was suggested that the insufficient K content in UEPY might lead the failure of fruit body production in the UEPY medium. The supplementation of KCl into the UEPY medium the most effectively increased the fruit body yield. 5. It was also suggested that the fungus required the different doses of mineral elements for supporting mycelial growth and fruiting.

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Samples of mycelium-colonized compost were taken from cultures of the edible mushroom, Agaricus bisporus during fruit body development. The steady-state levels of messenger RNA for led and cel3 genes were assessed by the use of Northern blot and competitive PCR analysis. The level of the laccase transcripts, for lcc1 was greatest in colonized cultures prior to fruiting, declined to non-detectable levels during fruiting and increased after harvesting and in second flush cultures. For the cel3 gene no transcripts were detectable from colonized pre-fruiting cultures. Levels rose to a maximum at the fruit body veil break stage, declined, and then increased again in the second flush. Gene expression for laccase and cellulase therefore correlates directly to the measurable level of extracellular enzyme activity.

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Various methods were examined to apply judgment for sawdust-based culture maturity of shiitake, Lentinula edodes, at different fruit body development stages. Glucosamine content showed a peak at the fruit body senescent stage. Glucosamine increased steadily to the sporophore senescent stage, and then declined sharply crop treatment. Lipid phosphate and ergosterol contents showed a peak at pinning and button break stages, respectively. The content of both were quite higher at the fully colonized stage prior to fruiting and increased rapidly on the fruiting culture, and were concluded to the convenient measurement for judgment of culture maturity and fruiting potentials. These methods may be applicable for detecting the fungal growth and maturity in L. edodes sawdust-based culture. The maturity linked to control the fruit body flush timing.

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The Effects of the storage temperature, length of storage, and wrapping the mushrooms in plastic film on the suppression of rotting in fruit-bodies during postharvest storage in Maitake-mushroom (Grifola frondosa (Dicks.: Fr.) Sing.) were surveyed. The amount of exudate in weight from fruit bodies causing by autolysis was applied as an index for the progress of rotting. The amount of exudate from the fruit bodies that were preserved by wrapping with plastic films was increased by increasing the storage temperature from 3 to 22℃. The storage of fruit bodies at 3℃ for 3 weeks, wrapped with any one of plastic films tested (polyvinylidene chloride: 10 μm in thickness, polyethylene: 10, 35 and 63μm in thickness) produced only a small amount of exudate. On the other hand, a remarkable amount of exudate was produced when stocked at 16 and 22℃ to 2 weeks, regardless of the kinds of films. The thicker films may suppress the rotting of fruit bodies in the storage at home.

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