Protease immobilized nanoparticles: a cleaner and sustainable approach to dehairing of skin

Leather industry has been undergoing a paradigm shift from chemical to enzyme-based processes for removal of hair and opening up of fibers from skin prior to its conversion into leather. This involves the use of protease for hair removal and amylase for opening the fibers in the place of sodium sulfide and calcium hydroxide, respectively. The enzymes are currently applied through various methods such as the use of salt, kaolin, and sawdust. Additionally, the robustness of the enzymatic approach under various environmental conditions needs to be ensured to enhance its popularity. With a view to this, the possibility of utilizing enzyme immobilized on zinc oxide nanoparticles was explored. Enzyme immobilized nanoparticles (nano-biocatalyst) at a concentration of 1.0% was optimized for hair removal, and compared to conventional sodium sulfide method. The decrease in the time required for matching efficiencies has been observed with the use of nano-biocatalyst. Histopathology results confirmed that there is no distortion of fibers with the usage of nano-biocatalyst. The study demonstrates the potential use of enzyme immobilized nanoparticles in leather processing and could ideally turn out to be a sustainable approach on account of reduction in emission loads from the process.