Enzyme discoveries that will fuel the future

Wheat straw, spruce chips and wheat bran are all considered as waste materials from different industries, and are found in great abundance across Europe. A major constituent of them is lignocellulose, a complex mixture of carbohydrate molecules bound to lignin, the component that forms the basis of wood. Lignocellulose is what gives trees and plants their strength, and durability, and it is these properties that have held back the exploitation of lignocellulosic materials for biofuel production. The molecular nature of lignocellulose makes it resistant to the actions of microorganisms that could otherwise convert it to simple sugar molecules needed to make biofuels.

The new EU-funded project, known as DISCO, is searching for microorganisms that can degrade the lignocellulosic material. Microorganisms obtain their energy from breaking down the complex molecules in nature and turning them into simpler sugars and further to energy. The DISCO project is hoping to find species of microorganisms which have evolved the highly specialised ability to break down the resistant lignocellulose material.

Libraries of microorganisms are a key resource for the research community, and the DISCO project is making full use of them. For example, the Budapest University of Technology and Economics (BUTE), a partner in the DISCO project, holds a library of over 4000 different microorganisms obtained from a multitude of different sources. From these a number of promising candidates for lignocellulosic enzyme activity have already been identified and are being further characterised in the labs of other DISCO project partners.

"We're looking to nature to find answers to the problem of efficiently generating next-generation biofuels from renewable sources, in this case from abundant waste materials from farming and industry," said Professor Kristiina Kruus, an expert in the enzymology of plant cell wall polymers. "That answer could literally be lying in the soil, in an undiscovered and uncharacterised microorganism."

The overall aim of the project is to end up with a cocktail of microorganism-derived enzymes that can simultaneously breakdown the complex lignocellose into simple sugars, and enable yeast co-fermentation to produce bioethanol. Initially a pilot scale plant will be developed. However, the starting materials, wheat straw, bran and spruce, are found in abundance throughout Europe as waste materials, so it is hoped that the DISCO project will lead to full scale plants producing biofuels across the continent.