Wood-boring marine bug the four-spotted gribble aids biofuel research

The Times
January 28, 2009
Lewis Smith, Environment Reporter

A marine bug that eats boat bottoms and pier supports has been identified as the likely key to improving the efficiency of biofuel production.
Four-spotted gribbles are able to break down cellulose in wood to make sugar. Scientists are convinced that by mimicking the process they will be able to produce better biofuel.
Research is under way to pinpoint the enzymes produced in the bug's stomach, and the genes that control them, so that the process can be applied to woody biofuel crops such as willow.
The investigation is being carried out as part of research by the Sustainable Bioenergy Centre, a £27million initiative announced yesterday that is the biggest public investment in bioenergy research.

Getting at and breaking down the cellulose in woody plant material, such as wheat husks, straw and miscanthus grass, is a difficult task for biofuel producers. At present they lose more than 30 per cent of the potential energy and are anxious to identify how it is achieved in the natural world by organisms such as gribbles, termites, bacteria and fungi.
Gribbles, which live in pairs in holes bored into wood, were identified as ideal subjects for study because while many other creatures digest wood, such as shipworms, they are the only ones which have guts devoid of microbes.
The absence of microbes is expected to make the hunt for the enzymes and genes easier because the digestive system should be easier to understand.
Professor Simon McQueen-Mason, of the University of York, said of the gribble: “It's an isopod — it's like a marine woodlouse. It's a few millimetres long and bores into wood. The reason we focus on the gribble is that it is very unusual in that it has a sterile digestive tract.
“The gut is like a reactor with wood. We can go straight to the gribble itself and isolate the genes and enzymes that are involved in that wood degredation.”
The four-spotted gribble, Limnoria quadripunctata, is one of four species of gribble native to British waters, and is found mainly on the South Coast. More than 50 species are found worldwide.
Four-spotted gribbles are known to have caused damage to Yarmouth Pier in the Isle of Wight and to underwater wooden structures at Portsmouth Harbour, where it is collected for research.
Professor McQueen-Mason said that before becoming a scientist he was a fisherman in the Isle of Wight, where he had to clean the bottoms of wooden boats and became aware of the wood-boring abilities of the creature.
The study is being carried out on behalf of the Sustainable Bioenergy Centre, which was set up by the Biotechnology and Biological Sciences Research Council (BBSRC). The role of the centre, which will have bases at several universities, is to improve biofuel production so that dependence on fossil fuels can be reduced.
Second-generation biofuel crops include willow and other woody vegetation that is more difficult to break down into sugars and then to into ethanol than the first-generation crops.
Unlike first-generation biofuel crops, they can be grown without competing against food crops because they can thrive on marginal land. They can also include unwanted agricultural materials such as waste straw and husks.
Lord Drayson, the Science and Innovation Minister, said in London that the centre should play a significant role in helping Britain to reduce its fossil fuel consumption.
Professor Douglas Kell, the BBSRC chief executive, said of the creation of the research centre: “This is a huge breakthrough for second-generation biofuels. It's the way forward — one day our cars could be run by fuel obtained from straw.”