Experimental evidence for presence of a growth regulating extracellular laccase in some pleurotus species

Abstract

The aim ofthe present study was to find out a common laccase isoenzyme in five Pleuratus spp. which might be responsible for regulation of mycelial growth in producer organisms. Laccase activities were assayed from the extracellular culture filtrates and optimum dates for laccase production under stationary condition were detected. Partially purified 25th days culture filtrates were analyzed for activity staining in 10% Native PAGE. The culture filtrate of all the strains had shown the oxidization of o-dianisidine, guaiacol and ABTS with different efficiencies. P. ostreatus showed optimum laccase activity in 25th day whereas other strains shown optimum activities in 26th day. The highest laccase activity and biomass were found in P. ostreatus and lowest in P. florida. Though different Pleuratus species exhibited differentiallaccase isoenzyme expression patterns but one isoenzyme band had been found to be common in all the species, which resulted in similar r f value with that of a previously reported growth regulating laccase (L2) of P. florida.