Proteins and biosurfactants: Structures, functions, and recent applications

Synergies between surfactants and proteins are found everywhere in everyday life. Beneficial interactions are exploited in fields such as food processing, pharmaceutical production, and laundry, leading to better products and lower energy consumption. Nevertheless, there is still room for improvement regarding sustainability. Here, biosurfactants (BS) are an attractive alternative to petrochemical surfactants. Insights into BS-protein interactions can help replacing traditional surfactants with BS and uncover new opportunities. Here, we review recent work on proteins' interactions with BS, with focus on the self-assembly of protein:BS complexes and BS’ effects on enzymatic activity. Generally, interactions are milder than those with traditional ionic surfactants, leading to modest effects on protein structure and self-assembly, while enzymatic inhibition is generally observed above BS' critical micelle concentration. Mild interactions between proteins and BS show promise in forming functional complexes with proteins, however, further studies are required to understand and minimize the detrimental effects that do occur.