Recent fermentation developments for improved rhamnolipid production

Rhamnolipids (RL) are microbial amphiphilic molecules containing a hydrophilic rhamnose head and a hydrophobic fatty acid tail. RL are of interest to academia and industry due to their potential as a biosurfactant, being used to substitute petroleum-based surfactants in traditional applications or in novel bioremediation and biomedical applications. Currently, commercialization of RL is still in a nascent state, and improved RL production in terms of titers, yields, and productivities could benefit their techno-economic viability and market competitiveness. This review provides a detailed assessment of recent studies that have achieved higher RL production through improvements in microbial producers, media formulation, fermentation design, and operations. Key successes and areas for future work are identified and discussed in detail, as well as put into context with pilot-scale and techno-economic analysis of RL production from the wider literature. This review provides an updated perspective on the current status of RL production. The discussions and insights provided could potentially be used to improve future RL and biosurfactant commercialization efforts.