Nutritional and Environmental Conditions for the Growth of Coriolus versicolor, a Wood Decaying and Medical Fungus

Abstract

Coriolus versicolor is a wood decaying fungus, it also has been used as a medicine in chinese tradition to cure many chronic diseases. However, it is also a harmful fungus on the logs in shiitake cultivation. Heavily infection of the logs by C. versicolor easily wiped out the production of shiitake. Three isolates of C. versicolor were used to explore the nutritional requirements and environmental conditions for the mycelial growth and fruiting body formation of C. versicolor. Results of the PDA plate culture indicated that all three isolates grew very well between 28 and 32℃ and 12 hours of alternating lights was better than continuous light or darkness. In stationary liquid culture, optimal pH value and C/N ratio were 6.0 and 81 Glucose and mannose were superior to the other carbon sources. A, nmonium chloride was best among the nitrogen sources. Urea and sodium nitrite hampered the mycelial growth of C. versicolor. Medium amount in the culture container also affected its mycelial growth. In the 300ml flasks, best growth was found with 120ml of medium or 2.5/1 (v/v). Among the amino acids used in the mycelial growth tests, DL-asparatic acid was found best and DL-3: 4 dihydroxy phenyl-alanine was harmful. In sawdust cultures, best growth was recorded at the moisture content of 54%. Although the cultural filtrate of C. versicolor inhibited the mycelial growth of C. versi-color itself, agar medium containing 1000 or 2000ppm of the cultural filtrate of C. versicolor favored the mycelial growth of shiitake (Lentinus edodes). Formation of fruiting bodies of C. versi color was observed 4 months after inoculation in the sawdust medium consisting of rice bran, wheat meal and calcium carbonate as it is used in shiitake cultivation.