Enhanced functionality and stabilization of a cold active laccase using nanotechnology based activation-immobilization

• A nanomaterial laccase (cold tolerant) system exhibited altered characteristics.
• Nano Cu (NP) enhanced activity and stability of laccase at 4 °C.
• Nanotube trapped laccase (+NP) stability at thermal extremes (4°, 80 °C).
• Multiple trap-release cycles retained laccase activity at the thermal extremes.
• Nanotube trapped laccase (+NP) maintained activity following repeated freeze–thaw.

A simple nanotechnology based immobilization technique for imparting psychrostability and enhanced activity to a psychrophilic laccase has been described here. Laccase from a psychrophile was supplemented with Copper oxide nanoparticles (NP) corresponding to copper (NP-laccase), the cationic activator of this enzyme and entrapped in single walled nanotube (SWNT). The activity and stability of laccase was enhanced both at temperatures as low as 4 °C and as high as 80 °C in presence of NP and SWNT. The enzyme could be released and re-trapped (in SWNT) multiple times while retaining significant activity. Laccase, immobilized in SWNT, retained its activity after repeated freezing and thawing. This unique capability of SWNT to activate and stabilize cold active enzymes at temperatures much lower or higher than their optimal range may be utilized for processes that require bio-conversion at low temperatures while allowing for shifts to higher temperature if so required.