Production optimization and molecular structure characterization of a newly isolated novel laccase from Fusarium solani MAS2, an anthracene-degrading fungus

To investigate the potential of laccase production from strain Fusarium solani MAS2, the response surface methodology (RSM) was employed, and the maximum laccase activity of 159.78 U ml(-1) was obtained at 20 C and pH 6.5 with 30 mg l(-1) of initial concentration of anthracene as the sole carbon source. Characterization of this laccase showed the similar properties with other reported laccases; however, the molecular identification, including matrix assisted laser desorption ionization-time of flight-tandem mass spectrum (MALDI-TOF-MS/MS) and gene cloning, demonstrated that this laccase was different from those available laccases, and only shared high homology with a non-identified, hypothetical oxidase from genome-sequenced strain Nectria haematococca, which was further annotated to be laccase. Further analysis on its nucleotide and amino acid sequences showed three introns present without detectable N-terminal signal peptide, indicating that this laccase might be synthesized within the cells. (C) 2013 Elsevier Ltd. All rights reserved.