Bioactive molecules from haloarchaea: Scope and prospects for industrial and therapeutic applications

Abstract

Marine environments and salty inland ecosystems encompass various environmental conditions, such as extremes of temperature, salinity, pH, pressure, altitude, dry conditions, and nutrient scarcity. The extremely halophilic archaea (also called haloarchaea) are a group of microorganisms requiring high salt concentrations (2–6 M NaCl) for optimal growth. Haloarchaea have different metabolic adaptations to withstand these extreme conditions. Among the adaptations, several vesicles, granules, primary and secondary metabolites are produced that are highly significant in biotechnology, such as carotenoids, halocins, enzymes, and granules of polyhydroxyalkanoates (PHAs). Among halophilic enzymes, reductases play a significant role in the textile industry and the degradation of hydrocarbon compounds. Enzymes like dehydrogenases, glycosyl hydrolases, lipases, esterases, and proteases can also be used in several industrial procedures. More recently, several studies stated that carotenoids, gas vacuoles, and liposomes produced by haloarchaea have specific applications in medicine and pharmacy. Additionally, the production of biodegradable and biocompatible polymers by haloarchaea to store carbon makes them potent candidates to be used as cell factories in the industrial production of bioplastics. Furthermore, some haloarchaeal species can synthesize nanoparticles during heavy metal detoxification, thus shedding light on a new approach to producing nanoparticles on a large scale. Recent studies also highlight that exopolysaccharides from haloarchaea can bind the SARS-CoV-2 spike protein. This review explores the potential of haloarchaea in the industry and biotechnology as cellular factories to upscale the production of diverse bioactive compounds.

Characterization of Plant-Growth Promoting Archaea Associated with the Rhizosphere of Salsola stocksii and Atriplex a

“…A number of previous studies also showed that halophilic archaea includingHaloferax , Halobacterium, Halococcus , Haloarcula , and Halorubrum have heavy metal resistance genes on their plasmids and chromosomal DNA. These microorganisms help plants to grow under saline polluted soils [27][28][29].…”

“…Halophilic archaeal genera includingNatrinema, Halobacterium and Halococcus have been reported for P-solubilization and production of organic acids such as citric, succinic, oxalic, lactic, acetic and isovaleric acids [20,26]. Halophilic archaea isolated from hypersaline polluted environments also have the ability to tolerate heavy metal resistance for nickel, cadmium, uranium, chromium and zinc [27][28][29].…”

PHBV cycle of life using waste as a starting point: from production to recyclability

“…Additionally, they produce other biomolecules with high biotechnological interest, like carotenoids (Flemming, 2016;Giani et al, 2019;Giani et al, 2022;Giani et al, 2021;Pfeifer et al, 2021) and exopolysaccharides (Flemming, 2016;Costa et al, 2018;Blackburn and Green, 2022). Besides, some haloarchaea can be used in the bioremediation processes to remove heavy metals and inorganic anions from brines and salty water (Oren, 2010;Nájera-Fernández et al, 2012;Martínez-Espinosa et al, 2015;Hou and Cui, 2018;Zuo et al, 2018;Pacholak et al, 2021;Pfeifer et al, 2021;Martínez et al, 2022;Moopantakath et al, 2023). Within haloarchaea, the most promising microorganism is Haloferax mediterranei (Pfeifer et al, 2021;Hagagy et al, 2022;Costa et al, 2023;Diankristanti et al, 2023), because it can synthesize PHBV without using any HV precursor (as required by other microorganisms) and can use different carbon sources to accomplish it (Tan et al, 2014b;Han et al, 2015;Parroquin-Gonzalez and Winterburn, 2023).…”

Bacterioruberin: Biosynthesis, Antioxidant Activity, and Therapeutic Applications in Cancer and Immune Pathologies

“…Haloarchaea have attracted global scientific attention due to their unique features related to the molecular machinery of nitrogen, biodegradable polymers, and carotenoid metabolism; their easy manipulation; their reduced space requirements for cultivation compared to other organisms like microalgae or yeast from which highly marketed compounds can be obtained; and their capacity to produce a wide array of biomolecules and metabolites with potential biotechnological applications compared to plants, bacteria, fungi, or eukaryotic algae [8,9]. Their remarkable resilience and functionality even in the face of challenging environmental conditions, including high salinity, intense ultraviolet (UV) radiation, elevated ion concentrations, and extreme temperatures and pH, make them good model organisms to be used as cell factories for different purposes compared to their bacterial counterparts [10][11][12].…”