Bilateral BBSRC-FAPESP - New approaches towards improved functionality of saccharolytic enzymes from fungi

This project proposal brings together scientists from the UK and Brazil in a collaborative project, relating to the production of biofuels, where they each bring expertise. There is a need to find realistic alternatives to the use of fossil fuels worldwide and there are targets for the amount of energy to be provided from renewables in many countries including the UK and Brazil. Those targets are challenging but the production of biofuels from agricultural wastes is targeted to make a contribution to the energy needs of many countries. Brazil leads the world in the production of ethanol from the fermentation of sugar by yeast to ethanol ('bioethanol'). That is an example of a first-generation process but that is not realistic in the UK where crops are grown for food and there is no capacity to grow crops specifically for biofuels. Therefore, second generation biofuels are designed to use non-food crops and one way of achieving that is to use agricultural waste materials. Those wastes do not contain easily-fermented sugars but they do contain a lot of plant cell wall material that is comprised mainly of cellulose and other polymers. In the production of second generation biofuels, these polymers are first degraded by enzymes to sugars and the sugars are then converted to ethanol by yeast. That enzyme step uses enzymes from fungi (moulds) that do that job naturally. That natural capacity of moulds needs to be understood so that it can then be transferred to a successful industrial process. Our previous research has shown that different fungi approach the problem of degrading polymers in different ways and this project aims to learn from those fungi in order to optimise the process.

This is a bilateral UK-Brazil proposal that brings together scientists from three leading laboratories that have current research into the use of filamentous fungi to produce enzymes for the saccharification of wheat straw (UK) and sugar cane bagasse (Brazil). Their existing data underpin the proposal that will use Aspergillus niger, Trichoderma reesei and Penicillium chrysogenum to provide new knowledge on aspects of the saccharification process. Those species respond to the lignocellulosic materials in different ways, especially with the induction of glycosyl hydrolases (GHs) and accessory proteins that optimise the functionality of the GHs. The market is already reasonably well-served with cellulases from fungi (mainly Trichoderma reesei) but less so with hemi-cellulases and accessory enzymes or non-enzymic proteins that assist in the process. Our preliminary data provide new leads relating to accessory proteins and also with the signals that regulate gene expression at the appropriate time when Aspergillus and Trichoderma are exposed to wheat straw. This project will build on those data to include sugar cane bagasse as another lignocellulosic material and the project will test the following hypotheses: i) that the combined polysaccharide-degrading activity of multiple fungi from distinct genera is more effective than that of each species alone, as this more accurately reflects plant cell wall degradation in nature; ii) that the functionality of fungal enzymes used in the saccharification of lignocellulose can be enhanced by previously undiscovered proteins that do not themselves catalyse the saccharification of lignocellulose. We will combine the respective strengths of the Nottingham group (e.g. RNAseq applied to fungal transcription) and those in Brazil (plant cell wall structure, fungal culture and proteome studies) with the aim of optimising fungal enzyme cocktails for release of sugars from wheat straw and bagasse.

Who will benefit from this research?
The principal beneficiaries will be all those who benefit from improved supply of bioenergy from biorenewables: companies, consumers, government. It is expected that the fungal research community will benefit from the research and especially those who study the regulation of gene expression or those who are engaged in research into the saccharification of biomass by fungal enzymes. While that is to be expected, there are other potential beneficiaries. Firstly, there is a widening discussion of renewable energy as an issue of government policy and public interest. Therefore, advances made in this project have the prospect of contributing to policy (what is possible in this area?) and to public debate. Also, there is the possibility that the new knowledge delivered by this project will provide new opportunities for applications. There are existing suppliers of fungal enzymes and a growing market for fungal enzymes at the commercial scale, so those companies will benefit from this research. Our initial research has already led to a high profile publication that suggests ways in which enzyme cocktails might be improved and this proposal builds upon that knowledge.

How will they benefit from this research?
At the research level, the new knowledge provided by the project will suggest new lines of research and will accelerate existing lines of research. Policy makers at government and inter-government levels will benefit by having a better understanding of innovation in the area of producing second generation biofuels that may influence predictions of what is realistic in terms of the conversion of plant materials to biofuels. Biofuels are an increasing part of our daily lives (e.g. fuels for cars) and the general public are increasingly exposed to information about biofuels. It is possible that this project will contribute to the debate about what is possible in the generation of biofuels, where the obstacles are and how to overcome them. The proposers would expect that the staff employed on this project would be very employable either academically or by industry. The timescale of impact is harder to estimate. It is not the aim of this project to have an immediate route to application but it is not unrealistic to suggest that the industrial companies could evaluate and adapt some of the findings from this project within 5 years.