Operative utility of salt-stable proteases of halophilic and halotolerant bacteria in the biotechnology sector

Abstract

Proteases are universal in existence in all organisms and are needed for metabolic activities of the cell. Also, proteases are the paramount hydrolytic enzymes widely used in industrial sector accounting ~65% of the aggregate worldwide enzyme market. The market revenue of global protease sale is estimated to be $ 2.21 billion by 2021. Currently, a widening expectation of biotechnology sector necessitates the availability of robust protease with industrially suitable operative features. The commercially-compatible protease should show stability and altered specificity in organic solvents, and be economically as well as ecologically sustainable. The proteolytic halophilic and halotolerant microorganisms are a novel source of salt-stable proteases. Beside stable in the presence of significant amount of salt, the halo-proteases could occasionally display the polyextremophilic attributes like tolerance to alkaline pH, high temperature, and organic solvent tolerance etc. This review describes - halophilic/halotolerant proteolytic microorganisms as source of salt-stable protease, mechanisms of high salt tolerance, various physical and nutritional parameters affecting the protease production, purification strategies for protease, characteristics of salt-stable proteases, and commercial significance of salt-stable proteases. The study revises the current status of the research on salt-stable proteases obtained from extremophile with their operative utility in the biotechnology field.

Keywords: Biomedical industry; Bioremediation; Detergent industry; Food industry; Halophiles; Halotolerant; Ionic liquids; Leather industry; Organic solvent; Salt-stable proteases.