Purification and characterization of two thermostable laccases with high cold adapted characteristics from Pycnoporus sp. SYBC-L1

摘要: Abstract The white-rot fungus Pycnoporus sp. SYBC-L1 produced large amount of laccase in submerged fermentation. Two isozymes (LacI and LacII) were purified using (NH 4 ) 2 SO fractionation, DEAE-cellulose Sephadex G-100 column chromatography. molecular masses LacI Lac II 55.89 63.07 kDa, respectively by SDS-PAGE. Both the laccases showed acidic pH optima high catalytic activities at low temperature for oxidations 2,6-dimethoxyphenol (DMP), 2,2-azino-bis-(3-ethylbenzothiazoline-6-sulfonate acid) (ABTS), syringaldazine guaiacol. LacII not only with cold adaptation, but also fairly stable temperature. half-lives 50, 60 70 °C 69.31, 2.58 0.13 h, respectively, whereas was more 256.72, 21.00 2.06 h respectively. best substrates enzymes both found to be ABTS, which K m values 0.0166 0.0435 mM efficiencies 19640.36 31172.64 S −1  mM , EDTA concentration Cu 2+ Mn almost had non-inhibitions on their activities. syringaldehyde efficiently decolorized Remazol Brilliant Blue R. thermostabilities as well adapted properties made excellent candidates harsh industry.