Phialophora Melinii (NFCCI 3617): A Newly Isolated Psychrotolerant Fungus That Produces Enhanced Laccase Under the Influence of Organic Solvents

Abstract

A psychrotolerant fungus, isolated from decomposing pine needle debris, is investigated for laccase production under the influence of 5 organic solvents. The fungus was identified as Phialophora melinii and was able to grow between 4 to 35 °C (opt. 25 °C) and 2-14 pH (opt. 5-7). In quantitative estimations that were carried out at optimum growth temperature and pH, the fungal laccase was estimated to be 21.0 ± 4.0 U/L. Native PAGE study revealed 35 kDa molecular mass of the fungal laccase. Supplementation of organic solvents namely, methanol, ethanol, acetone, n-propanol and iso-propanol in varying concentrations (0.5%-2.0%, separately), significantly affected the production of fungal laccase. Out of 5 solvents used, n-propanol was found to be the most efficient enhancer of laccase production. n-Propanol (0.5%) resulted in maximum enhancement (7 folds) in laccase production at 18th day of incubation. Methanol, iso-propanol and ethanol were able to enhance laccase production up to 5-6 folds in comparison to control with respect to the varying concentration and incubation length. Age of the fungal culture (incubation days) was observed as an important factor for laccase production. Use of low molecular compounds in enhancing the fungal laccase production may be considered as an eco-friendly approach.