Optimizing Laccase Production in Auricularia Cornea by Submerged Fermentation With Wheat Bran Extract: Applications in Decolorization of Malachite Green Dye

Abstract Wheat bran extract may enhance laccase activity of Auricularia cornea in submerged fermentation. The laccase activity of A. cornea was maximal (768.78 U/mL) at 26.9 ℃, pH 5, a time point of 6 d, 22 h, and an inducer concentration of 10%. Laccase from A. cornea AC5 decolorized 83.27% of 75 mg/L malachite green within 12 h. High performance liquid chromatography (HPLC) analysis of the extracted metabolites suggested that the decolorization occurred through biodegradation. Malachite green induced cytotoxic damage including formation of a micronucleus and chromosome bridge at anaphase. Degradation products of malachite green proved to be less toxic and had negligible effects on chromosomal aberrations.