How can plant waste be used to develop novel materials and products by utilising natural mechanisms in a solid-state biorefinery?

Project Goal: To determine whether bulk waste agricultural material can be reduced via novel low energy processes to produce high value chemicals suitable for further refining into polymers, pharmaceuticals, solvents and fuels.  Existing methods of treating agricultural waste use high-temperature, high pressure processes and have tended to focus on the production of relatively low value fuels such as ethanol.  This project set out to investigate the feasibility of using controlled fungal or bacterial processes to carry out the initial break down of the agricultural waste and to then investigate how the resulting chemical sludge can be refined to produce high value products such as polymers, lubricants, oils or fine chemicals.

Relevance of the Research:  This project aimed to create a sustainable, low energy, low cost manufacturing process capable of producing existing or novel materials for use in a wide range of applications including healthcare and the automotive industry.  The project team envisaged a highly efficient process that would take many types of agricultural waste, such a straw, and produce high value chemicals plus a residue that could be then refined into bio-fuel.

The Approach: The work was focussed on delivering the following key objectives 

• Plant genetics (Guy Barker / David Pink, HRI)
• Microbiology (Kerry Burton / Dan Eastwood, HRI)
• Chemical biology (Tim Bugg / Mark Ahmad, Chemistry)
• Organic chemistry (Andy Clark / Alana Collis, Chemistry)
• Chemical engineering (Claudia Koncsag, WMG)
• Polymer manufacturing (Kerry Kirwan / Stuart Coles, WMG). 

Partner Involvement: As the work was highly speculative there were no industrial partners involved at the start of the work.  However, as the research progressed a number of companies became involved including Boots Pharmaceuticals, SEKO (Sweden), Corgis and Akzo Nobel, the latter funding one PhD student to conduct research associated with the project aims.  SEKO supplied samples of lignin waste for tests to determine its suitability for biorefining while Cognis (a subsidiary of BASF) supplied samples of surfactants to assist in polymerisation reactions.

Research Outputs:

• It has been determined that different fungal and bacterial species produce different metabolic profiles when applied to the same substrate. One fungal species in particular produced a waxy layer as a by-product containing some commercially attractive materials.
• Procedures have also been developed that show applying two fungal species to the straw in different orders will also produce a different metabolic mixture.
• A library of potentially available chemicals has been generated which includes compounds such as vanillin and ferulic acid

Publications: The project has so far led to the publication of four peer reviewed journal papers

Notable Impacts:

• The fluorescence assay for lignin breakdown is novel, and will be of considerable use for the identification of new lignin-degrading strains. A paper describing this assay has been submitted to the RSC journal Molecular BioSystems.
• The identification of small molecule lignin breakdown products is also novel. These compounds are suitable for conversion to new materials such as polyester or polyurethane polymers.
• Kerry Burton gave a paper in August 2009, at the ‘Science in Society’ meeting in Cambridge, about the ethical and societal concern of bio-fuels and other environmental technologies and how politicians must use a range of evidence to make decisions about the adoption of these technologies.
• The work on a fluorescent assay for lignin degradation has led to a successful bid to the BBSRC IBTI Biorefinery Club by Tim Bugg, resulting in a 3-year post doctoral grant worth £480,000.  Tim Bugg also applied successfully for a PhD studentship from the Tuck Foundation (Enerbio) to study the enzymes of lignin degradation.
• Work from the WOW project was featured in the WIMRC funded WorldFirst racing car project which received recognition in Time Magazine (Top 50 inventions of 2009).
• The project was also showcased as part of the “Warwick on Wheels” road show which exhibited at The Gadget Show Live 2011.

Next Steps

The project team is currently actively pursuing IP protection of the process and applying for EPSRC follow-on funding

Interested? For further information and to discuss possible future collaboration please contact Kerry Kirwan, Head of Sustainable Materials, WMG, University of Warwick, CV4 7AL.