Hydrolytic enzyme protease in sludge: Recovery and its application

Excess of sludge generated by industries and municipal waste treatment is becomes a serious issue, mainly due to the growth of population and urbanization or development of new cities and the increases in the industrial activity. Protease refers to a group of important enzymes that hydrolyze or breakdown the protein molecules and involved in variety of biochemical pathways in living cells. They are required for many cellular functions because they are very useful in the digestion as they breakdown the peptide bonds in the protein of food stuff and liberate the amino acids needed for the body. Proteases have been used for a long time in various forms of therapy and industrial application. Industries like paper mills, pulp mills, textile industries and leather industries generate significant amounts of biodegradable sludge. This sludge is an industrial waste and contaminates the environment. Microorganisms degrade this sludge and produce protease and other hydrolytic enzymes. Biodegradation of the industrial sludge would be a great effort in terms of waste management as well as recovery of valuable protease for multifarious application. Emerging evidence from the literature proves the competence and vast application of protease for mankind. It has been used in many applications in the fields of food, medicine, fabric, leather in past decades. Present manuscript describes the key issues related to protease recovery from different industrial and municipal sludge using different approaches and its potential application in life.