A Biofactory for the Production of High Impact Flavour and Fragrance Compounds

挥发性有机硫化合物(VOSCs)是一种高冲击性的香料和香料(F&F)，其天然变种是珍贵的精细化学品。这个为期三年的项目的目标是利用生物催化中的植物和微生物多样性，从天然原料中衍生出一种新的生物工艺，用于商业生产VOSCs。由于F&F市场的专业性，正在开发的创新工艺被设计为适用于使用生物反应器技术可持续生产一系列VOSC。该项目由世界高影响力F&F精细化学品制造商牛津化学有限公司(OCL)领导，汇集了硫磺天然产品生物化学(达勒姆大学生物活性化学中心)、应用生物催化(Novacta BiosSystems)和生物反应器操作(加工创新中心)方面的专业知识。将采取的方法是基于两个层次的战略。在目标1(0-18个月)中，我们将开发一种基于酶的生物工艺，用于从天然产品前体扩大生产VOSCs。这一目标将提供在项目开始后18个月内生产新的高影响芳香化学品(HIAC)的能力。在目标2(12-36个月)中，我们将开发发酵技术，从基本的天然原料中可再生地生产VOSC前体。这一目标将提供使用新的代谢工程持续生产VOSC前体的手段，并将为该财团提供生产天然HIAC的新使能技术。技术途径是建立一种生物生产方法，使用保守的中心代谢途径和定制的酶控制底物的入口和产物的出口来生产各种VOSC化学物质。该方案建议使用三肽谷胱甘肽(？-Glu-Cys-Gly)作为供体，将硫引入到精油成分或植物浓缩物中发现的活性天然产品受体分子中。这种“进入”反应将由植物谷胱甘肽转移酶催化。使用重组细菌，得到的谷胱甘肽结合物将通过核心代谢途径进行处理，该途径依次将谷氨酸和甘氨酸部分水解，形成简单的半胱氨酸结合物。在该过程的最后阶段，半胱氨酸偶联物随后被“退出”的C-S裂解酶作用，该酶裂解半胱氨酸偶联物，使硫原子进入VOSC。拟议途径的所有最终产品和副产品都具有商业价值，该过程既减少了浪费，又最大限度地减少了能源消耗。达勒姆大学在该联盟中的学术合作伙伴的角色是开发使用生物反应器技术应用生产VOSCs所需的基础科学和技术(生物催化剂和代谢工程专业知识)。

Volatile organo-sulphur compounds (VOSCs) are high impact flavour and fragrances (F&Fs), with their natural variants being premium-valued fine chemicals. The objective of this three year project is to harness plant and microbial diversity in biocatalysis to derive a novel bioprocess for the commercial production of VOSCs from natural feed-stocks. Due to the specialized nature of the F&F market, the innovative process being developed is designed to be applicable to the sustainable production of a range of VOSCs using bioreactor technology. The project is led by Oxford Chemicals Ltd (OCL), a world player in high impact F&F fine chemicals and brings together the expertise in sulphur natural product biochemistry (Centre for Bioactive Chemistry, Durham University), applied biocatalysis (Novacta Biosystems) and bioreactor operation (Centre for Processing Innovation). The approach to be adopted is based on a two-tiered strategy. In objective 1 (0-18 months) we will develop an enzyme based bioprocess for the scaled up production of VOSCs from natural product precursors. This objective will deliver the capability of producing new high impact aroma chemicals (HIACs) within 18 months of the start of the project. In objective 2. (12- 36 months) we will develop fermentation technology to renewably produce VOSC precursors from basic naturl feedstocks. This objective will deliver the means to sustaniably produce VOSC precursors using novel metabolic engineering and will provide the consortium with new enabling technology to produce natural HIACs. The technical approach has been to establish a method for bioproduction which can produce a diverse range of VOSC chemistries using a conserved central metabolic pathway with custom enzymes controlling the entrance of substrates and the exit of products. The programme proposes to introduce sulphur into reactive natural products acceptor molecules found in essential oil components or plant concentrates using the tripeptide glutathione (?-Glu-Cys-Gly) as the donor. This 'entry' reaction will be catalysed by plant glutathione transferases. Using recombinant bacteria, the resulting glutathione conjugates will then be processed through a core metabolic pathway which sequentially hydrolyses the glutamate and glycine moieties to leave a simple cysteine conjugate. In the final stage of the process, the cysteine conjugates are then acted on by the 'exit' C-S lyase enzymes which cleave the cysteine conjugate, leaving the sulphur atom incorporated into the VOSC. All end products and by-products of the proposed pathway are of commercial value with the process both reducing waste and minimizing energy usage. The role of the Durham University academic partner within this consortium is to develop the basic science and technology (biocatalyts & metabolic engineering expertise) required for the applied production of VOSCs using bioreactor technology.