Heterologous production ofPseudomonas aeruginosarhamnolipid under anaerobic conditions for microbial enhanced oil recovery

Abstract

This is the first study to achieve anaerobic and heterologous production of rhamnolipid. Results demonstrated the potential feasibility of Rhl as a promising strain to enhance oil recovery through anaerobic production of rhamnolipid.

Biodegradation of Petroleum Oil Effluents and Production of Biosurfactants: Effect of Initial Oil Concentration

“…In recent years, microorganisms have played a unique role in the degradation and detoxification of polluted soil and water environments, and this process has been termed bioreclamation (Mohammed et al, 2016). The diversity of bioemulsifiers/biosurfactants makes them an attractive group to play an important key role in various fields of industrial as well as biotechnological applications such as enhanced oil recovery (Changhong, 2018;Zhao et al, 2014), biodegradation of pollutants (Monika et al, 2018), and pharmaceutics. Environmental applications of microbial surfactants have been shown to be promising due to the solubilization of low-solubility compounds, their low toxicity, and their efficacy in improving biodegradation (Mohammed et al, 2016).…”

Enhanced rhamnolipid production of Pseudomonas aeruginosa SG by increasing copy number of rhlAB genes with modified promoter

“…In this study, 2.42 g l À1 and 3.56 g l À1 of rhamnolipid were produced by engineered strains PrhlAB and PoprAB in anaerobic medium, respectively. In other studies, we constructed an engineered strain P. stutzeri Rhl which produced 1.61 g l À1 of rhamnolipid under anaerobic conditions; 19 and P. stutzeri Rhl can produce 3.12 g l À1 of rhamnolipid under anaerobic conditions aer medium optimization. 21 Increasing the copy number of rhlAB genes with the modied promoter efficiently enhanced the anaerobic production of rhamnolipid by P. aeruginosa SG.…”

“…4,15 Over 65 years have passed since the rst rhamnolipid was described; studies on rhamnolipid production by P. aeruginosa are not a few. And conceivable strategies for rhamnolipid production improvement were studied, such as metabolic engineering, 16 production in heterologous hosts [17][18][19] and fermentation approaches. 20,21 In order to improve production of desirable product by microorganisms, researchers tend to use genetic modulation methods, such as overexpression of the key genes and increase the copy numbers of key genes.…”

Enhancing rhamnolipid production and exploring the mechanisms of low-foaming fermentation under weak-acid conditions

“…One of the major reasons was due to the severe foaming in fermentation [12][13][14]. Although a large quantity of fermentation strategies, including anaerobic [15,16] and solid fermentation [14,17,18] have attempted to solve the severe foaming, submerged liquid fermentation still seems to be the sole approach for the high-yield production of rhamnolipid at present [19]. Therefore, to reduce foaming behavior in submerged liquid fermentation of rhamnolipid have become an urgent requirement for the large-scale production and application of rhamnolipid [13].…”