Intracellular isoforms of laccases produce by Pleurotus ostreatus grown in liquid fermentation at different initial pH of the culture medium

Abstract

Pleurotus ostreatus was grown in liquid fermentation at different pH (3.5, 4.5, 6.5 and 8.5) of the culture medium for laccases production. The activity and isoforms number of intracellular laccases were determined at different pH (3.5, 4.5, 6.5 and 8.5) using 2,6-dimethoxyphenol as substrate. The maximum activity value (4800 U/gX) was observed in the culture at pH of 4.5 evaluated at the same pH. In all fermentations, laccase activity showed the maximal values at final of the culture. The lowest laccase activity (120 U/gX) was obtained in the culture at pH of 8.5 evaluated at pH 6.5. Different isoforms patterns of laccase were obtained depending on the pH of the culture medium. These results showed that pH is an important parameter for the activity and isoforms of intracellular laccases of Pleurotus ostreatus.