Enzyme from wood-eating gribble could help turn waste into biofuel

Scientists have discovered a new enzyme in an odd source that could prove an important step in the quest to turn paper, scrap wood and straw waste into liquid fuel.

To do this they turned to the destructive power of tiny marine wood-borers called ‘gribble’, which have been known to destroy seaside piers.

Gribble are of interest as they are voracious consumers of wood and have all the enzymes needed for its digestion. The enzymes attach to a long chain of complex sugars and chop off small soluble molecules that can be easily digested or fermented. The researchers identified a cellulase from gribble that has some unusual properties and used the latest imaging technology to understand more about it.

Using advanced biochemical analysis and X-ray imaging techniques, researchers from the University of York, University of Portsmouth and the National Renewable Energy Laboratory in the USA have determined the structure and function of a key enzyme used by gribble to break down wood.

The findings will help the researchers to reproduce the enzymes effects on an industrial scale in a bid to create sustainable liquid biofuels.

To create liquid fuel from woody biomass, such as wood and straw, the polysaccharides (sugar polymers) that make up the bulk of these materials have to be broken down into simple sugars. These are then fermented to produce liquid biofuels. This is a difficult process and making biofuels in this way is currently too expensive. 

Simon McQueen-Mason, the research team leader from the University of York, explains: ‘Enzymes are proteins that serve as catalysts, in this case one that degrades cellulose. Their function is determined by their three-dimensional shape, but these are tiny entities that cannot be seen with high power microscopes. Instead, we make crystals of the proteins, where millions of copies of the protein are arrayed in the same orientation.’