Research Article Laccase Production from a Temperature and pH Tolerant Fungal

License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Laccase production by a temperature and pH tolerant fungal strain (GBPI-CDF-03) isolated from a glacial site in IndianHimalayan Region (IHR) has been investigated. The fungus developed white cottony mass on potato dextrose agar and revealed thread-like mycelium under microscope. ITS region analysis of fungus showed its 100 % similarity with Trametes hirsuta. The fungus tolerated temperature from 4 to 48∘C ± 2 (25∘C opt.) and pH 3–13 (5–7 opt.). Molecular weight of laccase was determined approximately 45 kDa by native PAGE. Amplification of laccase gene fragment (corresponding to the copper-binding conserved domain) contained 200 bp. The optimum pH for laccase production, at optimum growth temperature, was determined between 5.5 and 7.5. In optimization experiments, fructose and ammonium sulfate were found to be the best carbon and nitrogen sources, respectively, for enhancing the laccase production. Production of laccase was favored by high carbon/nitrogen ratio. Addition of CuSO 4 (up to 1.0mM) induced laccase production up to 2-fold, in case of 0.4mM concentration. Addition of organic solvents also induced the production of laccase; acetone showed the highest (2-fold) induction. The study has implications in bioprospecting of ecologically resilient microbial strains. 1