Survival and Energy Producing Strategies of Alkane Degraders Under Extreme Conditions and Their Biotechnological Potential

Abstract

Many petroleum-polluted areas are considered as extreme environments because of co-occurrence of low and high temperatures, high salt, and acidic and anaerobic conditions. Alkanes, which are major constituents of crude oils, can be degraded under extreme conditions, both aerobically and anaerobically by bacteria and archaea of different phyla. Alkane degraders possess exclusive metabolic pathways and survival strategies, which involve the use of protein and RNA chaperones, compatible solutes, biosurfactants, and exopolysaccharide production for self-protection during harsh environmental conditions such as oxidative and osmotic stress, and ionic nutrient-shortage. Recent findings suggest that the thermophilic sulfate-reducing archaeon Archaeoglobus fulgidus uses a novel alkylsuccinate synthase for long-chain alkane degradation, and the thermophilic Candidatus Syntrophoarchaeum butanivorans anaerobically oxidizes butane via alkyl-coenzyme M formation. In addition, gene expression data suggest that extremophiles produce energy via the glyoxylate shunt and the Pta-AckA pathway when grown on a diverse range of alkanes under stress conditions. Alkane degraders possess biotechnological potential for bioremediation because of their unusual characteristics. This review will provide genomic and molecular insights on alkane degraders under extreme conditions.

Efficient biodegradation of petroleum n-alkanes and polycyclic aromatic hydrocarbons by polyextremophilic Pseudomonas aeruginosa san ai with multidegradative capacity

“…53 Besides, key enzymes of the glyoxylate cycle, isocitrate lyase and malate synthase, are induced by n-alkane. 54,55 Taking all these metabolic facts together, it becomes clear why the respiration levels of hydrocarbons do not entirely correlate with the degradation percentages.…”

Newly Isolated Alkane Hydroxylase and Lipase Producing Geobacillus and Anoxybacillus Species Involved in Crude Oil Degradation

“…These studies have led to numerous microorganisms and their enzymes to be isolated and characterized. Despite its complexity and inertness, alkane, which made up the major components of crude oil, can be broken down aerobically by groups of cooperative enzymes such as alkane hydroxylase, alcohol dehydrogenase, aldehyde dehydrogenase, esterase, and lipase [10,11].…”

“…Furthermore, most of the studies and current available commercial enzymes were done on various mesophilic microorganisms [3,11,13,14]. Thermophiles and their enzymes are more robust and stable as compared to mesophiles and psychrophiles.…”

Crude Cell-Free Extract From Deinococcus radiodurans Exhibit Anticancer Activity by Inducing Apoptosis in Triple-Negative Breast Cancer Cells

“…The approaches to treat TNBC are limited and a major challenge for breast cancer drug discovery facing the breast cancer field ( Reis-Filho and Tutt, 2008 ), making it necessary to formulate novel anticancer drugs. The survival strategies of extremophilic organisms are frequently accompanied by modifications of gene regulation and pathways of metabolic reactions, increasing the possibility of discovering pharmaceutically important novel and efficient metabolites ( Park and Park, 2018 ). The D. radiodurans employs pyrroloquinoline quinone (PQQ) ( He et al, 2003 ; Ishii et al, 2010 ) and carotenoids (deinoxanthine) as predominant secondary antioxidant metabolites ( Khairnar et al, 2003 ).…”