Halophiles: biology, adaptation, and their role in decontamination of hypersaline environments

Abstract

The unique cellular enzymatic machinery of halophilic microbes allows them to thrive in extreme saline environments. That these microorganisms can prosper in hypersaline environments has been correlated with the elevated acidic amino acid content in their proteins, which increase the negative protein surface potential. Because these microorganisms effectively use hydrocarbons as their sole carbon and energy sources, they may prove to be valuable bioremediation agents for the treatment of saline effluents and hypersaline waters contaminated with toxic compounds that are resistant to degradation. This review highlights the various strategies adopted by halophiles to compensate for their saline surroundings and includes descriptions of recent studies that have used these microorganisms for bioremediation of environments contaminated by petroleum hydrocarbons. The known halotolerant dehalogenase-producing microbes, their dehalogenation mechanisms, and how their proteins are stabilized is also reviewed. In view of their robustness in saline environments, efforts to document their full potential regarding remediation of contaminated hypersaline ecosystems merits further exploration.

Haloferax mediterranei, an Archaeal Model for Denitrification in Saline Systems, Characterized Through Integrated Physiological and Transcriptional Analyses

“…Hypersaline environments accommodate representatives of all the three Domains of Life, but when the salt concentration exceeds 16%, haloarchaea dominate (Andrei et al, 2012;Edbeib et al, 2016;Torregrosa-Crespo et al, 2019). Among them are several denitrifiers and the microorganism that has emerged as a representative model is Haloferax mediterranei.…”

Denitrifying haloarchaea within the genus Haloferax display divergent respiratory phenotypes, with implications for their release of nitrogenous gases

“…The biodiversity under hypersalinity is lower than in other, less extreme environments (Oren, 2002), but higher than one might expect. All three domains of Life are represented, but Haloarchaea have been found to dominate when the salt concentration exceeds 16% (Andrei et al, 2012;Edbeib et al, 2016;Torregrosa-Crespo et al, 2016).…”

Diversity of Culturable Halophilic Archaea and Bacteria from Chott Tinsilt and El Malah Salt-Lake in Algeria

“…In recent years, halophilic prokaryotes have been widely explored and have been found in a wide range of saline environments. For their biotechnological applications, extreme and moderate halophilic bacteria have received high attention (Edbeib et al, 2016;Margesin and Schinner 2001;Oren, 2002). However, culture-based methods remain an essential approach to obtaining new microbes that offer application of new potentials and an understanding of their ecophysiological and environmental functions (Menasria et al, 2018).…”