A consortium of EU-funded research institutes, universities and industrial partners is using spruce chips, wheat straw and waste bran as potential sources for fermentation by micro-organisms to produce bioethanol.
The consortium is also discovering new enzymes that could help carry out this process.
Wheat straw, spruce chips and wheat bran are all considered waste materials from different industries and are found in large quantities across Europe.
A major constituent of them is lignocellulose − a mixture of carbohydrate molecules bound to lignin, the component that forms the basis of wood.
Lignocellulose 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 micro-organisms that could otherwise convert it to simple sugar molecules needed to make biofuels.
The EU-funded DISCO project is searching for micro-organisms that can degrade the lignocellulosic material.
Micro-organisms 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 micro-organisms that have evolved the highly specialised ability to break down the resistant lignocellulose material.
Libraries of micro-organisms are a key resource for the research community and the DISCO project is making full use of them.
The Budapest University of Technology and Economics (BUTE), a partner in the DISCO project, holds a library of over 4,000 different micro-organisms obtained from a multitude of different sources.
From these, a number of promising candidates for lignocellulosic enzyme activity have already been indentified 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 Prof 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 micro-organism.’
The overall aim of the project is to end up with a cocktail of micro-organism-derived enzymes that can simultaneously break down the complex lignocellose into simple sugars and enable yeast co-fermentation to produce bioethanol.
Initially, a pilot-scale plant will be developed but the abundance of starting materials − namely wheat straw, bran and spruce − could lead to full-scale plants producing biofuels across the continent.