Scratching the surface
Roger Marchant asks whether chemicals produced by bacteria and yeast could replace the environmentally hazardous surfactants found in many everyday products
The Biologist 64(2) p7
Surfactants are a group of chemicals that have a daily impact on our lives and yet we have little awareness of their importance, or their ubiquitous use. The word 'surfactant' was coined many decades ago as a contraction of 'surface active agent', and has become a common term for a wide range of compounds that display physicochemical properties at the interfaces between liquids, gases and surfaces.
The most obvious manifestations of these effects are the foaming of liquids at the interface with air, and the stabilisation of emulsions formed of oil and water. It is these effects that make surfactants important components of the enormous range of detergents and surface cleaners we use every day.
Similarly, the emulsification capabilities of surfactants are crucial for the maintenance of stable emulsions in many foodstuffs, and in cosmetic and pharmaceutical preparations. There are even applications for surfactants in products such as paints and inks, and they are now finding a role in environmental remediation, particularly where hydrocarbon contamination or heavy metals are involved.
The world market for surfactants is huge, with total annual usage estimated to be more than 13 million tonnes.