Original Articles
Junyao He, Xuanyi Ye, Qingzhi
Abstract
The production of laccase from Armillariella tabescens by submerged fermentation was studied. Various agro industrial residues were tested to determine the most suitable solid substrate for laccase production. Wheat bran led to the highest levels of activity (6.1 U/mL) and was selected as substrate in this study. Peptone was the best nitrogen source for laccase production by this fungus. Ferulic acid, guaiacol as well as copper sulphate proved to be the effective inducers for laccase production, resulting in increases of activities higher than 50% as compared to control value. In addition, the effects of pH and temperature on enzyme activity were investigated. The optimum temperature and pH for the crude laccase were 45 °C and 1.5, respectively, when in citrate buffer, with 2, 2’-azinobis-( 3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) as substrate. Interestingly, the crude laccase is highly stable under acidic conditions, with pH values ranging from 1.5 to 5.0.