Characterization of thermoadaptive serine metalloprotease and application in waste management

Thermoadaptive enzymes offer new opportunities for bio-catalysis and bio-transformations owing to their ability to function over wide temperature ranges. Microbial alkaline proteases are important constituents of commercial enzyme preparations, accounting for more than 60% of the total industrial enzyme market. Fibrous proteins, such as horn, feathers etc. are abundantly available in nature as recalcitrant solid wastes. Extracellular alkaline proteases derived from microorganisms can be used for degradation of proteinaceous wastes and convert them into value-added products e.g. peptide concentrates or amino acids. The present study relates to the isolation of an extracellular, bacterial thermoadaptive serine metalloprotease from the soil. The purified protease showed a remarkable increase in thermostability (4 °C-100 °C) that was enhanced in the presence of Ca2+. The protease (+Ca2+) was utilized to efficiently degrade fish scales and feather to produce amino acids, as declogging agent and for removing blood stains from cloth with a short reaction time. The ability of the protease could be utilized in bulk for solid waste management providing for an eco-friendly and effective process.