Enhanced production of laccase using a new isolate of white rot fungus WR-1

A new strain of white rot fungus WR-1 isolated from tree bark was found to produce high activities of laccase during fermentation. A simple medium containing glucose gave laccase activity of 124 U/ml using WR-1. The fermentation medium was optimized using a combination of one factor at a time and orthogonal array methods. Optimized medium containing 2% starch gave laccase activity of 288 U/ml. These values are very high as compared to most of the reported strains. Hence, the new isolate was further explored for enhancement in laccase production. Laccase production was enhanced considerably by incorporation of copper in the medium. Addition of I MM copper gave laccase activity of 410 U/ml in optimized medium. Different aromatic inducers such as 2,5-xylidine, ferulic acid, p-anisidine, etc. were used in optimized medium to further enhance laccase activity. All the inducers stimulated laccase production. The highest laccase activity of 692 U/ml was achieved using 0.8 mM 2,5-xylidine with optimized medium. Thus, the new isolate WR-1 is an efficient and excellent producer of laccase. (c) 2005 Elsevier Ltd. All rights reserved.