Profiling of Intra- and Extracellular Enzymes Involved in Fructification of the Lingzhi or Reishi Medicinal Mushroom, Ganoderma lucidum (Agaricomycetes)

Fruiting bodies of Ganoderma lucidum have been widely used as a source of potent nutraceutical products. However, the key proteins involved in fructifying G. lucidum, to our knowledge, have not yet been reported. We evaluated the protein profile of fruiting and nonfruiting G. lucidum strains at various developmental stages: mycelia, spawn running, pinning, and fruiting body. Four strains of G. lucidum (GL-I to GL-IV) were grown in both liquid medium (mushroom minimal medium broth) and bags of wheat straw, after which the biomass and fruiting bodies were harvested. Enzyme studies revealed enhanced intracellular and extracellular enzymatic activities during the spawn run stage compared with that during mycelial growth in broth. The esterase and peroxidase activities increased significantly during the pinning of the fruiting cultures, thus indicating their positive role in fructification. Fourier transform infrared spectroscopy of proteins at 3 stages of cultivation-spawn run, pin head formation, and fruiting-exhibited the presence of hydrophobic amino acids and an ordered protein structure in fruiting strains (GL-I and GL-II), indicating the presence of hydrophobin proteins and their role in mushroom fructification. However, basic and aromatic amino acids predominated in the nonfruiting strain GL-IV, and an unordered protein structure was present, which indicate the positive role of hydrophobic amino acids and hydrophobin proteins in mushroom fructification.