14TSB_SynBio P2P: Pentoses to products

点击翻译按钮获取中文摘要

Synthetic biology provides extraordinary scope to bring engineering and biological approaches together to manufacture new devices and products. The earliest industrial impacts are expected to be in high value chemicals manufacturing, provided that reliable tools and services can be developed for biocatalyst development. Early success in synthetic biology applied to chemicals will have significant impact on the UK economy. The UK chemical industry comprises a major sector in the UK, with > 8% of the world market. In 2009, the UK had over 3,000 companies generating an annual turnover of around £55bn, and the sector has been growing at about 5% a year. However, the chemicals manufacturing industry is dependent on increasingly expensive oil and gas as the starting materials, and sustainable alternatives are needed. Fortunately, synthetic biology provides new opportunities to use wastes from agriculture, forestry and food processing to manufacture bio-based chemicals and drop-in biofuels. These wastes are rich in sugar polymers (cellulose and hemicellulose) that can be hydrolyzed to produce C5 and C6 sugars. Although the C6 sugars are already used widely as fermentation feedstocks, there are few economically viable uses for C5 sugars. Utilization of C5 sugars would transform the economics of bio-based manufacturing, by forming high value products from almost zero cost wastes. This project aims to develop innovative biocatalytic modules for conversion of C5 sugars to chemicals. Until now, the problem of engineering microorganisms for C5 utilization has employed a whole systems approach, based on metabolic engineering of naturally occurring pathways. Since these pathways are inefficient and the product range is restricted, we will use the engineering concepts of modularization, characterization and standardization to develop new, artificial pathways for C5 sugar conversion to chemicals. We will apply modularization by breaking the metabolic process down intocomponent metabolic units, to design flexible, interchangeable metabolic modules. These will then be assembled into complete biocatalytic systems to obtain optimum performance in manufacturing. The modules will comprise genes coding for enzymes needed to (a) convert C5 sugars to key metabolic intermediates (isocitrate or 2-oxoglutarate) and (b) convert the intermediates to useful chemical products. We will use a bioinformatics approach to design the most efficient and compatible sets of enzymes to assemble the modules. We will also check the metabolic map of E. coli to identify enzymes that would compete with our metabolic modules, so that we can delete the corresponding genes. We will then clone, express and characterize the enzymes (where literature information is missing), so that we can define and understand their behaviour and function when combined into the modules, and fine-tune the designs. We shall then proceed to construct defined, standardized core modules, and characterize their performance. Next, the modules will be interfaced with accessory metabolic modules to form useful chemical products, providing bespoke microbial systems for chemicals manufacturing. We will demonstrate a bespoke system for production of mesaconic acid, needed by Lucite for methacrylic acid production. This will identify any issues relating to context dependency and predictability, enabling the designs to be fine-tuned for robust, industrial biocatalysis. The new metabolic modules will provide standardized components for the chemicals manufacturing industry, enabling rapid, predictable assembly of new biocatalysts to manufacture chemical products. Modularity will greatly reduce development time for new biocatalytic processes and accelerate the journey to market. Overall, the project will reduce the commercial and technical risk associated with biocatalytic manufacturing.