Laccase from Truncatella angustata showing Pb2+ induced burst of activity and dye decolourization without mediator and carbon footprint in cold climate

Abstract

A cold-active laccase is required for multiple applications in cold climate, and reducing carbon footprint. Thus laccase from the psychrophilic fungus T. angustata BPF5 originally isolated from Baramullah (India) soil was characterized. The enzyme showed apparent molecular masses of 36 kDa and 49 kDa, maximal activity at 15 °C, >98 % activity between pH 3.0 and 5.0, and burst of activity in presence of Pb2+. The enzyme was stable at 15 °C and acidic pH (3.0–5.0) for 24 h losing only 30 % activity in 48 h. It was tolerant to Na1+ and other tested metals and organic solvents. The enzyme could decolourize dyes belonging to azo and triphenyl amine at cold temperatures, and without any mediator to spectrophotometric zero level. Pb+2 though amplified laccase activity had no impact on the dyes decolourization rate. The enzyme is potentially applicable in cold climate and unraveling the novel mechanism of Pb2+ induced burst of activity.