Purification and particular characterization of laccase from the Ling Zhi or Reishi medicinal mushroom Ganoderma lucidum (W. Curt.: Fr.) P. Karst. 447 (Aphyllophoromycetideae)

The Ganoderma lucidum strain 447 was cultivated in a 10-L fermentor. We used the ethanol-production residue (by wheat) (REP) as the growth substrate and Cu as an inductor. Ganoderma lucidum was grown for 8 days before laccase reached the highest yield (188,600 U L-1). The purification enzyme appeared as two-laccase isozyme bands on SDS-PAGE. The molecular masses were 43 and 56 kDa by SDS-PAGE. The pH optimum for 2,2'-azino-bis-[3-ethyltiazoline-6-sulfonate] (ABTS) oxidation was 3 in citric/acetic buffers. In this study, the optimum temperature for laccase activity was determined to be 30°C. The kinetic of laccase was experimented on using 12 phenolic substrates. The lowest Km values (0.0048 and 0.005 mM) were found for syringaldazine and ABTS, respectively.