Extracellular Laccase from a Newly Isolated Psychrotolerant Strain of Cladosporium tenuissimum (NFCCI 2608)

A newly isolated psychrotolerant fungus from cold desert in Indian Himalaya has been investigated for laccase production. Based on phenotypic and genotypic characters, the fungus has been identified as Cladosporiumtenuissimum. The fungus could grow between 4 and 30 °C (optimum 24 °C). In ABTS plate assays, the efficiency for enzyme production was relatively higher at low temperature. In quantitative estimations, the laccase activity was recorded almost twice (15.10 ± 0.78 UL⁻¹) at 14 °C in comparison to the activity (8.05 ± 0.94 UL⁻¹) at 24 °C. Optimum pH for fungal growth as well as laccase production was 5.5. The molecular mass of laccase determined by native PAGE was approximately 48 kDa. Km and Vmax values of the enzyme were determined as 0.21 mM and 0.38 mM min⁻¹, respectively. Addition of carbon and nitrogen sources and organic solvents (supplements) affected enzyme activity significantly; ethanol being the best enhancer.