monorhamnolipid

Monorhamnolipid is a subset of rhamnolipids, a class of glycolipid biosurfactants produced by certain bacteria. It consists of a single rhamnose sugar head group linked to a lipid moiety formed by two β-hydroxy fatty acid chains, yielding an amphiphilic molecule capable of lowering surface tension and stabilizing oil–water emulsions. Typical congeners feature lipid chains in the C8–C14 range, and the rhamnose head group provides hydrophilicity.

Production and biosynthesis: Monorhamnolipids are mainly produced by Pseudomonas aeruginosa via the rhl and rml gene pathways. The rhamnose donor comes from the rmlABCD pathway, while rhlA and rhlB enzymes assemble the lipid tails and form the mono-rhamnolipid. Environmental conditions, carbon source, and oxygen levels influence yield. Because P. aeruginosa is an opportunistic human pathogen, non-pathogenic producers or engineered strains are explored for safer production.

Properties: They exhibit low surface tension with a critical micelle concentration in the low milligram-per-liter range, and they effectively emulsify hydrophobic substrates. They are biodegradable and generally show lower acute toxicity than many synthetic surfactants, though toxicity is concentration dependent and can affect aquatic organisms.

Applications: Monorhamnolipids are studied for bioremediation of hydrocarbon-contaminated soils and waters and for enhanced oil recovery. They are also evaluated for use in cleaning formulations, agricultural adjuvants, and have potential antimicrobial or anti-biofilm activities in medical contexts.

Considerations: Production costs, regulatory issues, and the choice of safe production strains influence commercial use. Ongoing research aims to optimize yield, tailor lipid composition, and enable scalable fermentation.