Rhamnose lipids - biosynthesis, microbial production and application potential

Biosurfactants containing rhamnose and beta-hydroxydecanoic acid and called rhamnolipids are reviewed with respect to microbial producers, their physi ological role, biosynthesis and genetics, and especially their microbial ov erproduction, physicochemical properties and potential applications. With P seudomonas species, more than 100 g l(-1) rhamnolipids were produced from 1 60 g l(-1) soybean oil at a volumetric productivity of 0.3 g l(-1) h(-1). T he individual rhamnolipids are able to lower the surface tension of water f rom 72 mN m(-1) to 25-30 mN m(-1) at concentrations of 10-200 mg l(-1). Aft er initial testing, rhamnolipids seem to have potential applications in com bating marine oil pollution. removing oil from sand and in combating zoospo ric phytopathogens. Rhamnolipids are also a source of L-rhamnose, which is already used for the industrial production of high-quality flavor component s.