Phellinus linteus, a well-known traditional medicinal mushroom, has been shown to exhibit potent biological activity. Recently, functional foods using cultured mycelia of P. linteus have been widely produced. This review on P. linteus presents current uniform and stabilization technology using genetic analysis, establishment of a culture technique, and various function properties of its mycelia. In particular, functional research on various assays is presented that examine anti-oxygen, anti-tumor, anti-allergy, including some novel findings suggesting that the cultured mycelium of P. linteus and its effective components have the potential to be applied to future therapies of various diseases.

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Using substrates containing rice bran, wheat bran or their mixture as a nutrient, supplemented with or without 3% trehalose, fruit bodies of Lentinula edodes were cultivated. On wheat bran substrate with trehalose, the total yield and number of fruit bodies larger than "M" size and trehalose content in fruit bodies were comparatively greater than on that without trehalose. However, the L^* value of pilei, a factor of brightness, were not sufficiently high in any flush, after fruit bodies grown on substrate supplemented with trehalose were preserved at 15℃ for six days, suggesting that trehalose had no effect on freshness preservation. On taste evaluation, the total score was markedly higher for fruit bodies grown on wheat bran substrate than substrates with the other nutrients. Thus, trehalose supplementation favorably influenced yield, trehalose content and taste of fruit bodies grown on substrate with wheat bran as the nutrient.

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An assay using the coagulometer semi-automated mechanical clot detection system for determination of blood or other samples was adapted for determination of milk clotting activity (MCA). The detection range of MCA was 0.005 to 5mg/ml in rennet from Mucor miehei, with a liner relationship (γ=0.997) between the rennet concentration and clotting time. The relative standard deviation of activity was 4.93%. The coagulometer method showed improved sensitivity over the Arima method, the conventional method applied for determination of MCA. In addition, a high correlation was found between the coagulometer and conventional methods (γ=0.998). Determination of MCA in crude enzyme from various mushrooms also resulted in high correlation between these methods (γ=0.917).

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The relation between the invasive activity and mycelial growth rate of fungal contaminants was investigated for 6 kinds of edible mushrooms and 17 strains of contaminants collected from several mushroom cultivation sites in the Kyushu district of Japan. The growth index was determined as the ratio of the mycelial growth rate of the contaminant to that of the edible mushroom, and invasive activity was obtained by the dual culture method using glass tubes for each combination. Contaminants with mycelial growth rates that were almost the same as or less than those of edible mushrooms had lower levels of invasive activity to the edible mushroom, while contaminants with higher invasion activity also tended to have higher mycelial growth rates. Most contaminants that grew two or three times faster than the edible mushroom showed substantial invasion of edible mushroom colonies. These results showed that the magnitude of invasive activity of the contaminant can be estimated from the ratio of the mycelial growth rates.

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Using four strains of Ganoderma lucidum, the influences of strain and basic culture material on fruit body formation and angiotensin I-converting enzyme (ACE) inhibition were investigated. For all four strains, mycelial growth rate on SMY-agar medium showed a good correlation with the length of cultivation until fruiting was initiated on wood meal-wheat bran medium. In addition, no obvious in-strain differences were found for mycelial growth rate and the timing of fruiting initiation between wood meals with regard to the basic culture materials obtained from Prunus mume and Quercus serrata. In contrast, inhibitory effects of extracts from fruit bodies on ACE activity varied significantly among the strains. In conclusion, screening for the optimal strain in medicinal uses of G. lucidum requires direct evaluation of the pharmacological activity of extracts in addition to indirect evaluation of the productivity of fruiting bodies. Moreover, the potential use of pruned branches of P. mume as the basic culture material was verified.

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