New antifoul discovery - 100% effective AND green

by Nancy Knudsen on 9 May 2009 A spectacular new study has shown there to be a natural fungus that, when added to hull paint, may completely solve the barnacle problem on the hulls of boats in the future.

The microscopic fungus called 'streptomyces avermitilis' lives in the ocean and is extremely poisonous to acorn barnacles and other crustaceans. When an extract from this fungus is added to paint for the hulls of vessels, the surface remains entirely free from barnacles. This has been recently demonstrated in a study from Göteborg University in Sweden.

'The fungus affects the nervous system of barnacles, and you only need a tiny amount of fungal extract to have an effect,' Hans Elwing, Professor at the Department of Cell and Molecular Biology at Göteborg University, announced yesterday.

Growths on the hulls of all vessels increase friction, which slows the vessel, requiring more wind power or a higher fuel consumption - which in turn causes more emissions.

At Göteborg University there have been several research projects conducted attempting to create environmentally friendly paints which prevent organisms from attaching to surfaces.

The discovery of how this microscopic fungus affects barnacles was made by a research team specializing in surface biophysics. As little as a 0.1 percent mixture of pure fungal extract in paint is sufficient to prevent any growth of acorn barnacles. Traditionally effective anti-foul paints have been problematic for the environment since the poison in the paint dissolves and spreads into the water.

'A sensational finding is that the fungal extract is toxic only as long as the paint is on a painted surface. When the paint is dissolved in sea water, the activation of the poison appears not to take place, making the paint apparently harmless to organisms in the open sea,' says Hans Elwing.

The scientists are basing their work on a theory that the fungal extract makes the paint imitate the fungus's natural and environmentally friendly defense against being eaten. Hans Elwing also believes that many other organisms in the sea have developed this type of environmentally friendly protection.

'The discovery that this fungal extract counteracts the growth of barnacles will probably create quite a stir around the world. No naturally occurring substance has previously been shown to have such a dramatic effect on barnacles in combination with being so easily degradable in the environment and probably completely safe for humans,' says Hans Elwing.

Hans Elwing's research team has joined up with SP Technical Research Institute of Sweden in Borås and Stockholm to develop their ideas. It is hoped that innovations in nanotechnology will facilitate the creation of new anti-fouling paints for boats.

'The fungal extract is probably both cheaper and, above all, more environmentally friendly that the paints based on copper compounds available on the market today,' says Hans Elwing.

For more information, please contact: Hans Elwing, Professor of Surface Biotechnology, Department of Cell and Molecular Biology at Göteborg University, e-mail: hans.elwing [at] gmm.gu.se