Optimization of some variables that affect the synthesis of laccase by Pleurotus ostreatus

Abstract

The influence of initial pH, concentration of yeast extract, inducer, type of enzyme releaser and buffer system on the composition of a medium for laccase production by Pleurotus ostreatus DM-1513 was investigated. A 2⁵ full factorial experimental design was initially employed to evaluate the effects of these variables on the enzyme synthesis. Data analysis showed that low pH and high yeast extract concentration values, as well as the absence of both an inducer and a buffer system, had positive effects on the secreted enzyme levels, whereas the type of enzyme releaser did not have a significant effect. The highest levels of laccase activity (489–540 U/l) were obtained in optimization experiments using media with initial pH between 6.0 and 6.5 and yeast extract concentrations of 0–0.25%