S. AHAMED JOHN AND A. CHOLARAJAN
Abstract
Laccase activities were found after GLC analysis of culture liquid of mycelium extract Ganoderma lucidum grown on malt extract medium with or without inducers. These laccase enzyme (E.C.1.10.3.2 paradiphenol: oxygen oxidoreductase) catalysis the oxidation and polymerization of aromatic compounds in the presence of molecular oxygen. Laccase activity in the malt extract medium had on pH 3 -4 and was stable from pH 3- 10 during 24 hours at room temperature. This enzyme had wide substrates specificity on hydroquinone, methoxy-substituted monophenols and aromatic amines. The laccase activity was found only with compounds having a redox potential lower than 0.5 mV. The highest activity was obtained with methoxy, methyl-substituted p-hydroquinone and aromatic diamines. Some activity also occurred with the aliphatic compounds 3, 5 cyclohexadiene-1, 2 diol.