Current status of genetic engineering for sophorolipids production.

Sophorolipids are a family of microbial biosurfactants that contain a hydrophilic sophorose head and a hydrophobic fatty acid tail. Sophorolipids have gained prominence within both academia and the commercial biochemical industry due to their potential as a more sustainable and functional substitute for petroleum-based surfactants in many applications, both traditional and novel. However, the sophorolipids market competitiveness and economic viability face significant challenges from the current level of production performance, production costs, as well as selectivity of sophorolipids forms and their associated functional properties. Genetic engineering of the producer organisms, such as the workhorse Starmerella bombicola and others, could be a powerful tool to improve various aspects of sophorolipids production, including sophorolipids: titers, yields, productivities, novel forms, product selectivity, improved utilization of novel or sustainable fermentation feedstocks, process scalability, and process intensification. This review is designed to provide a focused look at the current status of genetic engineering for sophorolipids production, including assessments of notable studies on the generation of recombinant sophorolipid producers, their specific aims and achievements, as well as their associated challenges and knowledge gaps to be addressed. Additionally, further discussions on how the genetic engineering toolbox and physiological understandings of sophorolipid producers need to be further improved are also provided. The perspectives, discussions, and recommendations provided should aid future research and development endeavors to further improve the genetic engineering of sophorolipids producers, sophorolipids bioprocess development, and their further commercialization.