Effect of the carbon source and inoculum preparation method on laccase and manganese peroxidase production in submerged cultivation by the medicinal mushroom Ganoderma lucidum (W. Curt.: Fr.) P. Karst. (Aphyllophoromycetideae)

The genus Ganoderma includes medicinal species that belong to the group of white rot fungi due to their ability to produce extracellular ligninolytic enzymes: laccase and manganese peroxidase (MnP). The aim of this study was to evaluate the significance of various carbon and inoculum preparation methods for oxidative enzyme production by the medicinal mushroom G. lucidum. Mushroom growth, as well as the production of laccase and MnP, significantly depends on the inoculum age and cultivation method. Synthetic medium experiments have shown that xylose ensured the highest laccase activity of G. lucidum 447 accumulating 116 U L-1 after 12 days of submerged mushroom cultivation. In all lignocellulosic substrate experiment variants, laccase activity reached maximum after 8 days of mushroom cultivation. Analogical regularities were detected when the MnP activity was measured in submerged fermentation of ethanol production residue by G. lucidum 447. A more interesting finding is the fact that mycelium grown on solid agar medium and used as inoculum not only provided a 3-fold increase in laccase yield in submerged fermentation of both lignocellulosic substrates but also stimulated MnP accumulation by G. lucidum 447.