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Projects: Projects for Investigator
Reference Number	BB/M003523/1
Title	Mechanistic Enzymology of Bacterial Lignin Degradation
Status	Completed
Energy Categories	Renewable Energy Sources(Bio-Energy, Other bio-energy) 30%; Not Energy Related 70%;
Research Types	Basic and strategic applied research 100%
Science and Technology Fields	BIOLOGICAL AND AGRICULTURAL SCIENCES (Biological Sciences) 100%
UKERC Cross Cutting Characterisation	Not Cross-cutting 100%
Principal Investigator	Professor TDH Bugg No email address given Chemistry University of Warwick
Award Type	Research Grant
Funding Source	BBSRC
Start Date	29 November 2014
End Date	28 November 2017
Duration	36 months
Total Grant Value	£536,606
Industrial Sectors	Healthcare
Region	West Midlands
Programme
Investigators	Principal Investigator	Professor TDH Bugg , Chemistry, University of Warwick (99.999%)
	Other Investigator	Dr AD Cameron , School of Life Sciences, University of Warwick (0.001%)
Web Site
Objectives	The production of useful chemicals from lignin breakdown in good yield would be of considerable interest to companies involved in commodity chemicals production, plastics & bio-plastics manufacture, and fine chemicals production, and would be of great interest to companies working in biofuel & biorefinery applications, who could use these discoveries to add value to waste streams. TDHB has a current TSB-funded pilot study with Biome Bioplastics Ltd, who are interested in the production of aromatic chemicals from lignin that could be used to make bioplastics. Novel enzymes for lignin breakdown would also be of considerable interest to biocatalysis & enzymes companies, and TDHB has had discussions in March 2013 with Ingenza Ltd in this area.This research could therefore lead to intellectual property in areas of biotechnology, that would be protected with the advice of Warwick Ventures. The outputs of the research project would also be disseminated to local schools and the general public through an active schools outreach programme run by the Department of Chemistry, and through popular science articles.
Abstract	We wish to carry out detailed mechanistic and structural studies on two recently characterized bacterial lignin-degrading enzymes, a Mn superoxide dismutase enzyme in Sphingobacterium sp. T2, and Dyp peroxidases from Pseudomonas fluorescens and Thermobifida fusca, and to identify further accessory enzymes required for bacterial lignin breakdown.For Sphingobacterium Mn superoxide dismutase, we will study the catalytic cycle of this enzyme using pre-steady state kinetic methods, to establish whether the reactive species in the catalytic cycle is Mn(III) or hydroxyl radical. We will also seek to determine the crystal structure of this enzyme.We have recently found a 35 kDa Dyp peroxidase enzyme from Pseudomonas fluorescens that is active in vitro against lignocellulose, releasing a small molecule product. We will determine the structure of the product, and study the mechanism for its formation, using lignin model compounds. We have also recently determined the crystal structure of a Dyp peroxidase from Thermobifida fusca, which we will use to carry out directed evolution studies on this enzyme, to enhance its activity towards lignin substrates. As well as the primary lignin-oxidising enzymes, we believe that there are several important accessory enzymes and proteins for bacterial lignin degradation. In this project we will seek to identify an extracellular ferulate esterase enzyme responsible for hydrolysis of lignin-xylan ester linkages in lignocellulose; and we will seek to identify a redox protein responsible for quenching radical intermediates formed during lignin breakdown, for which we propose an extracellular dihydrolipoamide dehydrogenase as a likely candidate. We will then test combinations of accessory enzymes with Dyp peroxidases and Mn superoxide dismutase enzymes for bioconversion of lignin-containing feedstocks in vitro, and examine whether they can produce useful yields of small molecular aromatic products.
Publications	(none)
Final Report	(none)
Added to Database	08/04/16