Enhancement of minor laccases production in the basidiomycete Marsasmius quercophilus C30

The white-rot fungus Marasmius quercophilus C30 is able to produce several laccases. The proportion of the enzymes produced depends on culture conditi ons. On malt medium, LACI was produced continuously over the 14 days of the cultivation period and was the only activity detectable. Copper increased total laccase activity by a factor 10 and induced the transient expression of one or more extra laccases in the culture medium. A combination of coppe r and p-hydroxybenzoic acid made it possible to extend the expression of in duced laccase activities over the cultivation period and to reach a maximum activity 30 times higher than in non-induced culture. Extracellular laccas es produced in this last condition were eluted as four peaks on an anion ex change column and were partially characterized. (C) 2001 Federation of Euro pean Microbiological Societies. Published by Elsevier Science B.V. All righ ts reserved.