Challenges and prospects for microbial biosurfactant research

The use of surfactants spans most industrial fields due to their useful tensio-active properties. These typically chemically synthesized molecules face increasing scrutiny and regulation due to some combination of low biodegradability, toxicity, and a manufacturing process that requires nonrenewable resources such as petroleum-derived hydrocarbons. The resulting need for highly efficient environmental-friendly substitutes that are synthetized from renewable sources has been an important driver for microbial surfactant (biosurfactant) research. Recent advances have led to the commercial scale-up and new applications for biosurfactants, particularly glycolipids such as rhamnolipids produced by Pseudomonas and sophorolipids produced by Starmerella bombicola and other yeasts. The emerging market availability of these biosurfactants is certainly a remarkable achievement, and we anticipate that this is only the beginning. There is a long way to go to reach the full potential of the entire diversity of biosurfactants and their applications that have been discovered. We predict there will be a continuing acceleration in new developments in this area as we begin to discover and bring to fruition the full potential of these amazing molecules. Biosurfactant research is wide ranging, including: the search for new molecules and for microorganisms that produce them; the physicochemical characterization of biosurfactants; the use of genetic engineering and of -omics strategies to develop microbes with enhanced productivity or new biosynthetic capabilities; the use of nonconventional substrates and fermentation processes for the large-scale production of biosurfactants; and the use of green chemistry and enzymatic catalysis and for the production of novel bioinspired surfactants. These advances in biosurfactant research are presented in this book and some will be highlighted in this final summary chapter.