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

挥发性有机硫化合物（vocs）是一种高影响的香精香料（F&Fs），其天然变体是优质的精细化学品。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，为从天然原料中生产挥发性有机碳的商业生产提供一种新的生物工艺。由于F&F市场的特殊性，正在开发的创新工艺旨在适用于使用生物反应器技术可持续生产一系列vocc。该项目由牛津化学有限公司（OCL）领导，该公司是高影响力F&F精细化学品领域的全球参与者，汇集了硫天然产物生物化学（杜伦大学生物活性化学中心）、应用生物催化（Novacta Biosystems）和生物反应器操作（加工创新中心）方面的专业知识。将采用的方法基于两层战略。在目标1（0-18个月）中，我们将开发一种基于酶的生物工艺，用于从天然产物前体中大规模生产vocs。该目标将在项目开始后的18个月内提供生产新型高影响芳香化学品（HIACs）的能力。在目标2中。（12- 36个月）我们将开发发酵技术，从基本的自然原料中再生生产vocc前体。这一目标将提供利用新型代谢工程可持续生产vocc前体的手段，并将为该联盟提供生产天然HIACs的新技术。技术方法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酶控制底物的入口和产物的出口，可以生产多种挥发性有机化合物。该计划建议使用三肽谷胱甘肽(？-Glu-Cys-Gly)作为捐赠者。这种“进入”反应将由植物谷胱甘肽转移酶催化。利用重组细菌，产生的谷胱甘肽缀合物将通过核心代谢途径进行加工，该途径依次水解谷氨酸和甘氨酸部分，留下简单的半胱氨酸缀合物。在该过程的最后阶段，半胱氨酸偶联物随后被“出口”C-S裂解酶作用，裂解半胱氨酸偶联物，留下硫原子并入VOSC。拟议途径的所有最终产品和副产品都具有商业价值，该过程既可以减少浪费，又可以最大限度地减少能源使用。杜伦大学在该联盟中的学术合作伙伴的作用是开发使用生物反应器技术生产vosc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.