Optimization of wheat and oilseed rape straw co-products for bio-alcohol production

Various forms of biomass represent potential feedstocks for degradation and fermentation to produce alcohols as liquid biofuels, with residual protein-rich materials being suitable for further exploitation, such as processing for animal feed. This provides the potential to substantially substitute for fossil fuels, with the associated sustainability and environmental benefits. However, many of the sources evaluated in recent years, such as willow or Switchgrass, would compete directly with UK food crops for land use. With the growing recognition of the vulnerabilities of world (and UK) food security, and associated food price volatility, it is becoming increasingly clear that the displacement of food crops by crops grown solely for biofuel is inappropriate. There are, however, several sources of 'waste' biomass associated with the UK production and processing of food crops. These provide potential feedstocks for 'biorefining' to recover biofuels and animal feed from residues after grain/seed recovery. This approach does not compete with food crops; indeed the increased value of co-products such as straw should enhance the financial viability of food crop production in the UK. Major UK food crops such as wheat and oilseed rape produce more straw co-product than harvested grain or seeds. This straw constitutes a plentiful potential feedstock. However, these crops have been bred for the quality and yield of grain or seeds, not for the composition of the straw they produce. Past studies of straw composition have revealed surprisingly extensive variation between varieties (and between different morphological components of the straw) for the major chemical constituents of importance for bioalcohol production. We are already involved in an ongoing research programme, funded by Defra, which is developing the methodology for the efficient exploitation of biomass residues from the food chain. The proposed research dovetails with this project, providing the means to optimise the principal feedstocks: wheat and oilseed rape straw. Combined, these two projects will establish the supply chain (from breeders and farmers to bio-alcohol producers and the motor industry) needed to deliver the financial and societal benefits of the science. We aim to thoroughly analyse the composition of straw from current wheat and oilseed rape varieties, and of genetic material in use by breeders, for compositional characteristics of importance for biofuel production. We will use recently-developed technologies to explore variation of the sequences and expression of tens of thousands of genes in each of wheat and oilseed rape, and relate these genetic characteristics to the compositional characteristics of the lines in order to develop markers for use in subsequent breeding programmes. Using the information we have gained, we will hypothesise the processability characteristics of differing potential feedstocks and test these using a pilot plant system.

The purpose of this study is to evaluate wheat and oilseed rape straw from a range of varieties for key structural characteristics of the cell walls which determine both the potential yield of bio-alcohol from pentoses and hexoses, and the ease of degradation and fermentation. These characteristics will be related to the underlying genetic make-up of the feedstock. The latter will provide new opportunities for the future development of varieties with improved feedstock quality. The project involves three main research activities: (1) A survey of variation across wheat and oilseed rape germplasm (48 lines each of wheat and oilseed rape) and management regimes for the composition of straw for known determinants of processability for bio-alcohol production. (2) An understanding of the genetic basis for variation of processability traits will be developed and markers for the acceleration of subsequent breeding will be identified. (3) We will develop processability hypotheses and test them by the processing of materials through a pilot plant system. The lines selected for analysis represent the range of crop varieties presently available to farmers plus germplasm representing the genetic variation presently available to the breeding industry. Methods for morphological and analytical analyses are well-developed, drawing upon previous work of the research partners. Methods for marker discovery, as single nucleotide polymorphisms (SNP) are newly-developed and exploit 'next generation' sequencing technology to provide polymorphism data at around three orders of magnitude lower cost per locus than previous approaches for marker discovery, such as simple sequence repeats (SSR). This approach also provides an excellent quantification of gene expression using the same dataset.

The research consortium also involves two members of the industry: KWS UK is the UK's leading breeder specializing in both wheat and oilseed rape. They are a member of the IBTI club, which ensures efficient exploitation through the club. They also represent the initial industry beneficiary, as the recipient of knowledge of trait variation and SNP markers to assist breeding. Velcourt Ltd. is Europes largest Farm Management Company and is unique in the fact that they have their own Research and Development Department which undertakes a significant quantity of crop production trials each year. Velcourt are largely behind current thinking within the industry of the use of seed rates, nitrogen usage and different plant growth regulator types to manipulate crop height and straw strength. The consortium will draw on this knowledge and Velcourt (along with other farmers) will benefit from the project by gaining access to varieties with lignification and agronomic characteristics which mean that they can be grown successfully for their grain/seed and the straw can be sold to the bioalcohol industry. The partners in this project represent a complete supply chain for the optimization and supply of wheat and oilseed rape straw as feedstocks for bio-alcohol production: two research institutions, a plant breeder and a farm management company. The project integrates with an ongoing programme (LK0848) that has assembled partners representing the remainder of the supply chain to the consumer: a pre-processing engineer, an enzyme manufacturer, a bio-alcohol producer and a motor manufacturer. This supply chain is scalable into the industrial take-up phase. I. Bancroft and K. Waldron are both involved in LK0848 and will work together to ensure that the activities dovetail. Thus the anticipated joint outcome of these projects is the substitution of a significant proportion of fossil fuel used by the motor industry, and other applications, with biofuel. This represents a broad societal benefit, contributing to mitigation of climate change whilst reducing the cost of biofuels (by optimizing production efficiency) and UK-produced food (by adding value to wheat and oilseed rape straw co-product, making grain production more cost-effective, and by providing fermentation co-product as a low-cost animal feed, reducing the cost of livestock production). The sequence variation that we will characterize will be of value as molecular markers for use in the breeding of wheat and oilseed rape for many other traits, such as yield, disease resistance and input use efficiency. This project will also serve as an exemplar for the use of association genetics and association transcriptomics for the improvement of a wider range of crops. The proposed research supports UK government policy, which is to promote biofuels and support the EU objective of 10% renewable transport fuels by 2020. The latest biofuels position of UK government is based on the findings of the ''Review of the Indirect Effects of Biofuels'' authored by Professor Ed Gallagher, the head of the government's Renewable Fuels Agency. This report recommends that government should ''amend but not abandon its biofuel policy'' as biofuels can play a role in tackling climate change. It concludes that ''there is a future for a sustainable biofuels industry''. However, this must be achieved in a way that reduces the perception of biomass and biofuel crops pushing up food prices or leading to unsustainable land use changes. The proposed research fits precisely with this policy. It eliminates competition between food and biofuel crops as it synergises with food production, exploiting and adding value to waste products and