Enzyme breakthrough paves way for new plant waste products

A study led by Professor John McGeehan from the University of Portsmouth has discovered a type of enzyme with the unique ability to break down lignin – a key component in plants. The discovery paves the way for plant waste to be recycled in such a way to produce products including nylon, chemicals, plastics and fuels.

Detailing the study, Professor McGeehan explains: “we have assembled an international team for the discovery and engineering of naturally occurring enzymes. Enzymes are biological catalysts that can perform incredible reactions, breaking down some of our toughest natural and man-made polymers. To protect their sugar-containing cellulose, plants have evolved a fascinatingly complicated material called lignin that only a small selection of fungi and bacteria can tackle. However, lignin represents a vast potential source of sustainable chemicals, so if we can find a way to extract and use those building blocks, we can create great things.”

The study, published in Nature Communications, was also worked on by Dr Gregg Beckham at the US Department of Energy’s National Renewable Energy Laboratory (NREL), Professor Jen Dubois at Montana State University, and Professor Ken Houk at the University of California, Los Angeles.

Sam Mallinson, a PhD student in structural biology at the University of Portsmouth and first author on the paper adds: “there is a long-standing phrase – you can make anything out of lignin except money – but by harnessing the power of enzymes, this is set to change. Using advanced techniques, from X-ray crystallography at the Diamond Light Source synchrotron, to advanced computer modelling, we have been able to understand the detailed workings of a brand new enzyme system.”

In addition to the industrial benefits of the new enzyme, a greater reliance on lignin could alleviate the current dependency on oil in the manufacturing of consumer goods.