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

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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.