Halophilic hydrolases as a new tool for the biotechnological industries

Abstract

Halophilic micro-organisms are able to survive in high salt concentrations because they have developed diverse biochemical, structural and physiological modifications, allowing the catalytic synthesis of proteins with interesting physicochemical and structural properties. The main characteristic of halophilic enzymes that allows them to be considered as a novel alternative for use in the biotechnological industries is their polyextremophilicity, i.e. they have the capacity to be thermostable, tolerate a wide range of pH, withstand denaturation and tolerate high salt concentrations. However, there have been relatively few studies on halophilic enzymes, with some being based on their isolation and others on their characterisation. These enzymes are scarcely researched because attention has been focused on other extremophile micro-organisms. Only a few industrial applications of halophilic enzymes, principally in the fermented food, textile, pharmaceutical and leather industries, have been reported. However, it is important to investigate applications of these enzymes in more biotechnological processes at both the chemical and the molecular level. This review discusses the modifications of these enzymes, their industrial applications and research perspectives in different biotechnological areas.

Structural characterization of a unique marine animal family 7 cellobiohydrolase suggests a mechanism of cellulase salt tolerance

“…S6 F-H). Highly negative electrostatic potential surface is one of the hallmarks of halophilic proteins, which not only require salts for optimum activity, but also remain active at high ionic strength values (45). We also examined the hydrolytic activity of LqCel7B in high salt conditions using PASC and Avicel as substrates (Fig.…”

Halophile isolation to produce halophilic protease, protease production and testing crude protease as a detergent ingredient

“…Different groups of enzymes are produced in halophilic bacteria particularly protease; these enzymes serve various industrial purposes (Mariana Delgado et al, 2012). Proteases are a single class of derivative enzymes that catalyze the cleavage of peptide bonds leading to total hydrolysis of proteins.…”

Hydrolytic Enzymes in Halophilic Bacteria, Properties and Biotechnological Potential

“…High salt concentration limits availability of water in a microenvironment around the protein inducing some changes in structural and functional dynamics of most enzymes. Enzymes in this condition must adapt to compete with salts for hydration (Delgado-García et al 2012 ;Karan et al 2012a ) in order to prevent protein aggregation by reducing the number of hydrophobic residues and increasing acidic residues on the surface of proteins (Rao and Argos 1981 ). On exteriors of haloenzymes acidic residues give negative charges to enzymes and bind to hydrated ions, which reduce enzyme surface hydrophobicity and aggregation at high salt concentration (Klibanov 2001 ;Marhuenda-Egea and Bonete 2002 ).…”

“…On exteriors of haloenzymes acidic residues give negative charges to enzymes and bind to hydrated ions, which reduce enzyme surface hydrophobicity and aggregation at high salt concentration (Klibanov 2001 ;Marhuenda-Egea and Bonete 2002 ). In fact, haloenzymes have multilayered hydration shells to maintain their functional conformation in the presence of high ionic concentration (Delgado-García et al 2012 ;Karan et al 2012a ).…”