Sustainable rhamnolipids production in the next decade - Advancing with Burkholderia thailandensis as a potent biocatalytic strain

Abstract

Rhamnolipids are one of the most promising eco-friendly green glycolipids for bio-replacements of commercially available fossil fuel-based surfactants. However, the current industrial biotechnology practices cannot meet the required standards due to the low production yields, expensive biomass feedstocks, complicated processing, and opportunistic pathogenic nature of the conventional rhamnolipid producer strains. To overcome these problems, it has become important to realize non-pathogenic producer substitutes and high-yielding strategies supporting biomass-based production. We hereby review the inherent characteristics of Burkholderia thailandensis E264 which favor its competence towards such sustainable rhamnolipid biosynthesis. The underlying biosynthetic networks of this species have unveiled unique substrate specificity, carbon flux control and rhamnolipid congener profile. Acknowledging such desirable traits, the present review provides critical insights towards metabolism, regulation, upscaling, and applications of B. thailandensis rhamnolipids. Identification of their unique and naturally inducible physiology has proved to be beneficial for achieving previously unmet redox balance and metabolic flux requirements in rhamnolipids production. These developments in part are targeted by the strategic optimization of B. thailandensis valorizing low-cost substrates ranging from agro-industrial byproducts to next generation (waste) fractions. Accordingly, safer bioconversions can propel the industrial rhamnolipids in advanced biorefinery domains to promote circular economy, reduce carbon footprint and increased applicability as both social and environment friendly bioproducts.

Keywords: Bioprocess development; Biosurfactants; Di-rhamnolipids; Genetic optimization; Global regulators; Quorum sensing.