Reusing soy residue for the solid-state fermentation of Ganoderma lucidum.

Lingzhi has been a popular oriental medicine used to treat various human diseases. Soy residue from the waste of tofu manufacturing was used to culture Ganoderma lucidum in solid-state fermentation. The solid-state fermentation was conducted in three types of containers: test tube, 500-ml flask, and sterilize-able polypropylene plastic bag. The highest rate of mycelial growth of 6 mm/day was observed in the medium of carbon/nitrogen (C/N) ratio of 80 using test tubes. However, a growth rate of 7.5 mm/day was found at the C/N ratio of 70-80 in the 500-ml flasks. In the tests using plastic bags, the fruiting bodies were fully developed only for the C/N ratios of 70 and 80. The components of fruiting bodies obtained from different media were also analyzed and compared. The contents of ash, polysaccharides, and crude protein of fruiting bodies were found higher in the media of C/N ratio of 80.