An extracellular laccase with potent dye decolorizing ability from white rot fungus Trametes sp. LAC-01

• Published in: International journal of biological macromolecules Vol. 81; pp. 785 - 793
• Main Authors: Ling, Zhuo-Ren, Wang, Shan-Shan, Zhu, Meng-Juan, Ning, Ying-Jie, Wang, Shou-Nan, Li, Bing, Yang, Ai-Zhen, Zhang, Guo-Qing, Zhao, Xiao-Meng
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 01.11.2015
• Subjects: Chromatography, Liquid; Coloring Agents - chemistry; Copper - chemistry; DNA, Intergenic; Dye decolorizing activity; Enzyme Activation; Enzyme Stability; Fermentation; Fungi - classification; Fungi - enzymology; Fungi - genetics; Hydrogen-Ion Concentration; Kinetics; Laccase; Laccase - biosynthesis; Laccase - chemistry; Laccase - isolation & purification; Molecular Weight; Phylogeny; Substrate Specificity; Tandem Mass Spectrometry; Temperature; Trametes - classification; Trametes - enzymology; Trametes - genetics; Trametes sanguinea; Trametes sanguinea; Dye decolorizing activity; Laccase
• ISSN: 0141-8130; 1879-0003
• DOI: 10.1016/j.ijbiomac.2015.09.011

A novel laccase was purified from fermentation broth of white rot fungus Trametes sp. LAC-01 using an isolation procedure involving three ion-exchange chromatography steps on DEAE-cellulose, SP-Sepharose, and Q-Sepharose, and one gel-filtration step. The purified enzyme (TSL) was proved as a monomeric protein with a Mr of 59kDa based on SDS-PAGE and FPLC. Partial amino acid sequences were obtained by LC–MS/MS sharing considerably high sequence similarity with that of other laccases. It possessed optimal pH of 2.6 and temperature of 60°C using ABTS as the substrate. The Km of the laccase toward ABTS was estimated to 30.28μM at pH 2.6 and 40°C. TSL manifested considerably high oxidizing activity toward ABTS, but was avoid of degradative activity toward benzidine, caftaric acid, etc. It was effective in the decolorization of phenolic dyes – Bromothymol Blue and Malachite Green with decolorization rate higher than 60% after 24h of incubation. Adjunction of Cu2+ with the final concentration of 2.0mmol/L significantly activated laccase production with a steady high level of 275.8-282.2U/mL in 96-144h. The high yield and short production period makes Trametes sp. LAC-01 and TSL potentially useful for industrial and environmental application and commercialization.