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Chemicals which stick to the interface between gases and liquids are called surface active agents, or surfactants for short. When surfactants are at an interface they change its properties in important ways. They are essential for life itself. For example, it is the surfactants in a newborn baby's lungs which enable her to first draw breath. They also feature in almost every industrial production process, and are behind many everyday products we use from detergents to ink jet printing.Currently, most of the surfactants we use in industry and at home are produced from oil sources. However, some bacteria will produce surfactants whilst feeding on a range of materials. A surfactant produced in this way is called a biosurfactant. Although individual bacteria are microscopically small and produce only tiny amounts of product, many millions of millions of cells can be farmed to produce substantial amounts of product.Biosurfactants are very interesting. They can easily outperform synthetic oil derived surfactants, whilst having the attraction of being made from renewable resources. Also, the structures of biosurfactant molecules are much more interesting than synthetic ones, giving them many useful properties which synthetic surfactants just don't have. Unfortunately, they are also very, very expensive, and this really limits how much we can explore and take advantage of them.This interdisciplinary project will engineer a novel process for the production of one such biosurfactant called surfactin. The aim is to advance the process engineering of biosurfactant production in general; the objective is to slash the cost of surfactin to a tenth of what it is now. The process will combine four innovations in process engineering and microbiology. Experimentation will give scientific insight into the process, lead to new technology, and produce small quantities of surfactin. Commercialisation will lead to a step-increase in surfactin availability, and step-decrease in price.Surfactin was named after its outstanding properties as a surfactant. Surfactin was identified in 1968 from products of the bacteria known as Bacillus subtilis. Upon discovery it was seen to affect the interface between water and air more than any other surfactant known at the time, and at very low concentrations. Even today, the most powerful industrial surfactants struggle to match its power, and require the use of much greater amounts of chemical. For example, over 250 times as much TRITON GR-5M (the most powerful surfactant marketed by DOW, the world's largest chemical company) is required to match surfactin's action.The global surfactant market in 2003 was 12m tonnes, worth 8.8b. The market is extremely competitive, so products with a distinct advantage are highly prized. Aside from its superior surfactant power, surfactin is renewable, biodegradable, biocompatible and has low toxicity. Consequently, surfactin is particularly attractive for environmental uses, such as cleaning pollutants from soil and enhancing production from oil wells. Current production costs severely limit surfactin's exploitation; there are only a very small number of large scale plants in the world.Exploration and exploitation of surfactin's great potential in medicine and biotechnology has also been inhibited its very high price. Surfactin is currently available as a fine chemical with a price equivalent to 6500/g, that's almost 800 times more expensive than gold. This high price is a result of labour intensive, small scale batch production and complex separation processes.This project will employ the latest innovative techniques to increase the efficiency of all biosurfactant production, and thus lead to a step-decrease in price and step-increase in availability. With this people, industry and society in general will be able to benefit more fully from the uniquely useful properties of biosurfactants.
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