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

燃烧化石燃料产生的温室气体（GHG）排放是气候变化的主要原因。全球能源使用量不断增加，迫切需要可再生和减少温室气体排放的替代能源。随着全世界车辆数量的迅速增加，新型液体运输燃料尤为重要。植物是“生物太阳能电池板”。通过光合作用，植物捕获阳光能量并利用它将大气中的二氧化碳中的碳分子转化为碳水化合物。植物利用碳水化合物的能量来生长和生产新的干物质（生物量）。它们还以不同的形式储存碳水化合物作为储备。液体运输生物燃料可以通过发酵等生物转化过程从植物碳水化合物中生产出来。当碳水化合物以简单的形式存在时，如蔗糖和淀粉，这些酶的作用最好，因为它们很容易获得和分解。在英国，生物乙醇分别由糖和淀粉类粮食作物（如甜菜和小麦）生产。然而，种植这类作物需要大量的养分投入，特别是氮肥。由于氮肥的生产需要化石燃料，因此在整体节能或减少温室气体排放方面收效甚微。从可耕地作物中生产生物燃料也可能与粮食生产相冲突。多年生生物质作物，如柳树和芒草，是快速生长的非粮食作物，可以在少量氮肥的情况下产生生物质。从这些作物中提取的生物燃料将节省更多的能源，减少温室气体排放。然而，大多数碳是以木质纤维素的形式存在的，木质纤维素构成了植物的细胞壁，复杂的化学键使得酶很难接触到这种形式的碳。在BBSRC可持续生物能源中心（BSBEC）多年生生物能源作物计划中，我们将汇集植物生物学、作物育种、基因组学、生物化学、生物数学和生物能源方面的领先专家，以克服这些限制，从而巩固柳树和芒草所需的改进，从植物木质纤维素中开发生物燃料。我们的重点将放在：(1)优化生物质产量。我们将研究通过早期发展叶冠、延长生长季节和改善冠层结构来捕获更多能量的方法，我们将研究碳是如何分配到植物的不同部分的，如芽、根、器官、组织、细胞和细胞壁。(2)优化生物质组成（特别是细胞壁中碳的可及性），以加工成生物燃料。这将通过首先提高我们对生物量组成的理解来完成，它如何在芒草和柳树中自然变化，以及这种变化如何影响生物量的可加工性。我们还将使用基因发现技术来鉴定影响细胞壁组成和碳的可及性的基因。我们在培育和改良柳树和芒草方面有超过二十年的经验。我们在这两种作物上也取得了令人兴奋的科学领先。我们的工业合作伙伴（壳牌和Ceres）具有互补的优势和专业知识，将有助于在该计划中开发这些和新的创新，并将其推向国际市场。

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.