The BBSRC Sustainable Bioenergy Centre (BSBEC): Perennial Bioenergy Crops Programme

The greenhouse gas (GHG) emissions that result from burning fossil fuels are a major contributor to climate change. Energy usage is increasing globally and alternative forms that are renewable and reduce GHG emissions are urgently needed. New forms of liquid transport fuels are particularly important, as the number of vehicles is increasing rapidly worldwide. Plants are 'biological solar panels'. Through photosynthesis, plants capture sunlight energy and use it to convert carbon molecules from atmospheric carbon dioxide to form carbohydrate. Plants use energy from carbohydrates for growth and the production of new dry matter (biomass). They also store carbohydrates in different forms as reserves. Liquid transport biofuels can be produced from plant carbohydrates by biological conversion processes such as fermentation. These enzymatic processes operate best when the carbohydrates are in simple forms, such as sucrose and starch, as these are easily accessed and broken down. In the UK, bioethanol is produced from sugar and starchy food crops such as sugar beet and wheat, respectively. However, growing such crops requires high inputs of nutrients particularly nitrogen (N) fertilisers. As N fertilisers require fossil fuels to make there is little overall energy saving or reduction in GHG emissions. Producing biofuels from arable crops can also conflict with food production. Perennial biomass crops, such as willows and the grass Miscanthus, are fast growing non-food crops which can produce biomass with little N fertiliser. Biofuels from these crops would give higher energy savings and GHG reductions. However, most of the carbon is in the form of lignocellulose which makes up the plant cell wall and complex linkages make it difficult for enzymes to access the carbon in this form. In the BBSRC Sustainable Bioenergy Centre (BSBEC) Perennial Bioenergy Crops Programme, we will bring together leading experts in plant biology, crop breeding, genomics, biochemistry, biomathematics and bioenergy to over come these limitations and thus underpin the improvements needed in willows and Miscanthus to develop biofuels from plant lignocellulose. Our focus will be on: (1) Optimising biomass yield. We will investigate ways of capturing more energy by developing leaf canopies earlier and extending the growing season and by improving the canopy architecture and we will investigate how carbon is partitioned into different parts of the plant e.g. shoots, roots, organs, tissues, cells and cell walls. (2) Optimising the biomass composition (specifically the accessibility of carbon in cell walls) for processing to biofuels. This will be done by first improving our understanding of biomass composition, how it varies naturally in Miscanthus and willow and how this variation influences the processibility of the biomass. We will also use gene discovery techniques to identify genes that affect cell wall composition and accessibility of the carbon. We have over two decades of experience with breeding and improving willow and Miscanthus. We also have exciting scientific leads in both crops. Our industrial partners (Shell and Ceres) have complementary strengths and expertise that will help develop these and new innovation within the programme and bring it to international markets.

The need to reduce fossil fuel contributions to climate change is the most significant and pressing challenge of this century. The overall aim of the BBSRC Sustainable Bioenergy Centre (BSBEC): Perennial Bioenergy Crops Programme is to underpin the development of a sustainable biofuels sector by optimising feedstocks from perennial biomass (non-food) crops whilst maximising energy savings and minimising greenhouse gas (GHG) emissions. This programme will capitalise on (i) more than two decades of energy crop development and energy crop resources in Miscanthus and willow, giving the UK an internationally leading position; (ii) active breeding programmes linked to our research, which will allow the delivery of improved energy crops and;(iii) the active engagement of Shell and Ceres. Our science programme on Miscanthus and willow addresses two main objectives: (1) Optimising biomass yield. Approached by genetics, QTLs and genomics. Hypotheses (H) investigated are: H1: Radiation interception for C fixation may be maximised by improving thermal sensitivity and cold tolerance for early canopy expansion; H2: Carbon fixation may be maximised by altering crop morphology/architecture and, H3: Sustainable yields can be achieved by selecting for an optimal allocation ratio of above- (harvested carbon) and below-ground biomass (reserve carbon); (2) Optimising biomass composition. Approached by analytical and gene discovery routes. Hypotheses investigated are: H4: The efficiency of processing for sugar release and biofuel production can be improved by identifying and selecting for natural (and modified) crop variants with improved biomass composition and; H5: Improved understanding of cell wall synthesis and assembly can be exploited to develop new tools for selection of genotypes with improved accessibility of carbon in biomass.