Electrofusion of Pleurotus cornucopiae protoplasts was conducted using the glass electrode electrofusion technique in which a pair of protoplasts was put into contact under a microscope and an electrical pulse was applied. Initially, the protoplast of the basidiomycete was too small for the glass electrode, but after incubation in a mixture of cell lytic enzymes, it increased in size into a giant protoplast. In screening studies of natural compounds effective in inducing fruiting body development in Pleurotus ostreatus on agar medium, a triterpenoid saponin was found to exert a hormone-like effect. In order to study the structure-activity relationship, a betulin glycoside was synthesized by linking a sugar moiety to a triterpenoid betulin derived from the outer bark of Betula platyphylla. The sugar chain was further lengthened by transglycosylation using chemical and enzymatic reactions. Betulin with added sugar moieties induced fruiting activity in Pleurotus ostreatus; this fruiting activity correlated with the sugar length. In addition, 3-O-alkyl-D-glucose (AG), a novel hydrophobic compound with an attached sugar chain that has been proposed to trigger fruiting in P. ostreatus, was synthesized; AG with an eight-carbon alkyl chain was shown to effectively induce P. ostreatus fruiting bodies. Thus, it was proven for the first time that a sugar-containing amphipathic compound could stimulate fruiting body development.

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Pholiota microspora is a popular edible mushroom in Japan. Here, molecular methods used to discriminate the wild-type strains of P. microspora are reported. These methods are used to identify strains for use as breeding material. P. microspora was divided into two groups by the presence or absence of 24 bases in the V4 region of the mtSSU rDNA. Two extremely early maturing strains with fruiting bodies that form in June in the wild belonged to the group lacking the 24-base deletion. IGS1 sequences differed among the wild strains and cultivars, and the IGS1 region might serve as an informative site to discriminate wild strains and cultivars. RAPD analysis identified polymorphisms among wild strains.

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We ascertained the influence of a medium additive (Prunus mume flesh) on the anti-inflammatory effects of Ganoderma lucidum extracts. Anti-inflammatory effects were evaluated by inhibition of interleukin-8 (IL-8) gene expression and platelet aggregation. All extracts caused suppression of IL-8 expression. Hot water extracts led to the lowest expression of IL-8. Inhibition of platelet aggregation was higher for extracts of G. lucidum cultured on a medium including P. mume flesh than for extracts from G. lucidum cultured on a normal medium. An 80 ℃ water extract of G. lucidum cultured on medium containing P. mume showed the highest inhibition on platelet aggregation regardless of the tested aggregating agents. The inhibitory effect on platelet aggregation by G. lucidum extracts was enhanced by addition of P. mume to the culture medium. This observation suggests that the medium additive influences the pharmacological actions of the mushroom.

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A procedure for a preparation of a Lyopyllum shimeji inoculum in soil medium was developed and 71 isolates of the fungus were assayed for mycorrhizal formation in Pinus densiflora seedlings. Three months after inoculation, the inocula of L. shimeji were categorized into three types: type 1, in which the inocula were filled with dense white mycelia, remaining firm; type 2, which although the inside of the fungus was white, the masses of inocula were weak and collapsed easily; and type 3, in which the inocula were infected by mold contaminants and did not remain the original shape. For the isolates with all-healthy inocula, the inoculum type was determined by the isolate, and there was no effect on the mycorrhizal formation rate. In many isolates with inoclula classified as type 1 or 2, the mycorrhizal formation rate exceeded 60%. But for some isolates, the mycorrhizal formation rates were less than 10%. These results suggest that the capability of ectomycorrhizal formation varied and depended on the isolate.

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