Halophiles and Their Vast Potential in Biofuel Production

Abstract

Global warming and the limitations of using fossil fuels are a main concern of all societies, and thus, the development of alternative fuel sources is crucial to improving the current global energy situation. Biofuels are known as the best alternatives of unrenewable fuels and justify increasing extensive research to develop new and less expensive methods for their production. The most frequent biofuels are bioethanol, biobutanol, biodiesel, and biogas. The production of these biofuels is the result of microbial activity on organic substrates like sugars, starch, oil crops, non-food biomasses, and agricultural and animal wastes. Several industrial production processes are carried out in the presence of high concentrations of NaCl and therefore, researchers have focused on halophiles for biofuel production. In this review, we focus on the role of halophilic microorganisms and their current utilization in the production of all types of biofuels. Also, the outstanding potential of them and their hydrolytic enzymes in the hydrolysis of different kind of biomasses and the production of biofuels are discussed.

Extremophile Microalgae: the potential for biotechnological application

“…, Amoozegar et al. ). From a more applied industrial biotechnology perspective, MAAs are becoming important as compounds of interest to supplement and/or replace commercially available sunscreens, particularly as the requirement for natural products and replacement of petrochemical based products is growing (Llewellyn and Airs ).…”

“…, Coker , Amoozegar et al. ) as well as the field of astrobiology (Chyba and Hand , Martins et al. , Cottin and Rettberg , Joseph et al.…”

Haloferax volcanii for biotechnology applications: challenges, current state and perspectives

“…Lignin and its derivatives are considered as serious contaminants in paper and pulp industries, tanneries and textile mills due to their poor biodegradability and intense colour (Costa et al 2017;Raghukumar et al 2008). Given that waste streams in these industries contain high concentrations of recycled salt, halophilic enzymes capable of lignin degradation could play a pivotal role in biopulping and biobleaching processes (Amoozegar et al 2019). Laccase is a multicopper oxidase enzyme that couples oxidation of phenolic compounds to the four-electron reduction of molecular oxygen to water (Solomon et al 1996).…”

“…Halophiles have been important in natural salt production since they facilitate salt crystallization through the absorption of solar radiation using their carotenoid pigments, which confers distinct pink-reddish hues to the saltern crystallizer ponds they inhabit. More recently, halophiles have been used in biotechnology as producers of antimicrobials, bioplastics, biofuel, extremozymes, extracellular polysaccharides, retinal proteins, coloured pigments and compatible solutes (Amoozegar et al 2019;Atanasova et al 2013;Koller 2019;Patel and Saraf 2015;Torregrosa-Crespo et al 2017). This has led to their applications in astrobiology, agriculture, food and nutrition industry, biosensor development and photochemical industry, bioremediation, textile and tanning industry, aquaculture, nanotechnology, sustainable chemical production and medical application (Le Borgne et al 2008;Lee 2013;Margesin and Schinner 2001;Rodrigo-Baños et al 2015).…”

“…Easy growth conditions, a short generation time and facile genetics have made it a model organism for haloarchaeal biology (Allers and Mevarech 2005;Leigh et al 2011). It encodes numerous biotechnologically attractive halophilic enzymes with application potentials in sustainable fine chemical synthesis, bioprocessing, bioremediation, biofuel and bioplastic production (Amoozegar et al 2019;Koller 2019;Lobasso et al 2015;Timpson et al 2013;Uthandi et al 2009). Developments of tools such as bioreactor-scale overexpression of functionally active proteins and immobilization of cells within a porous matrix have opened up new possibilities in exploiting H. volcanii for biotechnological applications (Haque et al 2019;Strillinger et al 2016).…”