Halocin Diversity Among Halophilic Archaea and Their Applications

Abstract

Haloarchaea and their metabolites show unusual properties such as stability under extreme conditions and create special interest for the search of novel products. In recent years, studies on systematics have intensified and identified many new genera and species. Haloarchaea belonging to class Halobacteria are divided into three orders: Halobacteriales, Haloferacales, and Natrialbales consisting of more than 48 genera and 216 species. Haloarchaea and their metabolites are useful for various industrial applications. Halophilic proteins and enzymes produced by haloarchaea remain functional under high salt concentrations, extreme pH, and high temperature at which bacterial counterparts denature. These features make haloarchaea an attractive source of a wide variety of biotechnological products, such as retinal proteins, osmolytes, carotenoids, various hydrolytic enzymes, polyhydroxyalkanoates (PHAs), and exopolysaccharides. The biomolecules produced by haloarchaea have important role in manufacturing of bioplastics, photoelectric devices, artificial retinas, holograms, bioremediation process, and numerous other potential applications in biotechnology. Further study is more focused to develop a low-cost platform for low-cost downstream process with better yield at larger scale. Halocins are the proteinaceous antimicrobial proteins/peptides (AMPs) secreted by several members of haloarchaea. The production, purification, and characterization of halocins have been studied from various members of haloarchaea to understand the unique importance for their possible applications. The therapeutic potential of halocins needs more exploration to decipher an alternate to clinical antibiotics.