In this study, fermented black soybeans were prepared using Schizophyllum commune (NBRC 4928). The antioxidant activity of fermented black soybean was higher than that of boiled black soybeans. Examination of changes in the isoflavone componnents of fermented black soybeans revealed that the glycoside-type isoflavones, daidzin and genistin, decreased, while the aglycone-type isoflavone, daidzein, increased. The findings also showed that dihydrodaidzein was produced in the fermented black soybean suspension. It is suggested that the isoflavones that are produced by ferment black soybeans with S. aerialis have antioxidant charactristics.
Bioluminescence is of chemical, biological and ecological interest. Currently, greater than 80 fungal bioluminescent species have been documented. The chemical mechanisms of Mycena lux-coeli bioluminescence are still not clear. In this study, a bioluminescent system was identified in M. lux-coeli pileus gills. Bioluminescence in living gills was induced by addition of trans-3-hydroxyhispidin (1), and the induced bioluminescence exhibited a max of 525 nm, which was in agreement with that of natural bioluminescence. The light-producing enzyme from 1 was partially purified from M. lux-coeli gills. Trans-3-hydroxyhispidin-induced bioluminescence and natural bioluminescence were not affected by the addition of trans-3-hydroxyhispidin analogue 2, which did not contain a hydroxyl group at the C-3 position of the phenyl group in 1, but were significantly inhibited by the addition of trans-3-hydroxyhispidin analogue 3, which did not contain two hydroxyl groups at the C-3 and C-4 positions of the phenyl group in 1. The characteristics of 1-induced bioluminescence were consistent with those of natural bioluminescence. This study concluded that 1 is a bioluminescent substrate for the natural bioluminescence of M. lux-coeli.
Transcriptional analysis showed a dramatic increase in the expression of polyketide synthase gene 1 (pks1) in mature and post-harvest fruiting bodies of Grifola frondosa. Therefore, PKS1 may be closely associated with melanin biosynthesis in this polypore mushroom, and melanin synthesis via the 1,8-dihydroxynaphthalene pathway might play a role in fruiting body spoilage.