Biotransforming Phenylpropanoids derived from Biorefining: a Toolkit Approach

使用植物作为可再生原料来取代石化产品，需要在提炼和回收有用产品方面达到类似的效率水平。生物燃料生产是目前用于从植物生物质中回收平台化学物质的最先进的精炼方法，在生物燃料生产中，相当数量的物质是不可发酵的，在过程结束时仍是一种低价值的副产品。对这种残渣进行分馏并增加其成分的价值将提高生物精炼的效率、经济性和最终的可持续性。在未发酵的物质中，一种相对丰富且容易回收的化学物质是次生代谢物阿魏酸，这是一种苯丙烷(PP)，广泛用于植物中，用于制造具有生物活性的多酚化合物。在本项目中，我们建议使用阿魏酸和其他PPS作为前体，在代谢工程酵母中通过发酵生产二氢查尔酮及其糖基化衍生物。这些二氢查尔酮在食品工业中被广泛用作人工甜味剂和调味剂，目前都是通过非化学转化的方法制备。在我们的过程中，我们将重建在植物中产生多酚的途径，并将它们改造成酵母，酵母在接受PPS的喂养后，将通过可持续的生物过程生产这些人工调味剂。作为人工调味剂，使用基因改造来生产这些化合物不会影响它们的市场价值，因为它们不是“天然”产品。此外，我们设计的途径的模块化组装和特定PP前体的喂养使我们有可能生产新型的二氢查尔酮，这些产品有可能被开发成食品工业的新风味增强产品。因此，该计划将为现有的利用植物原料的发酵过程增加价值。此外，该工艺还将与旨在解构木质素的工艺高度兼容，木质素是由PP中间体组成的木质生物质产生的主要非发酵产物。因此，该项目既具有立竿见影的效用，又建立了对生物精炼行业具有长期价值的有用技术，这些行业已将木质素的分解和各自产品的使用确定为未来的一个主要商业机会。

The use of plants as renewable feedstocks to replace petrochemicals requires similar levels of efficiency in terms of refining and recovery of useful products. In biofuel production, which is currently the most advanced refining applied to recover platform chemical from plant biomass, a considerable amount of material is non-fermentable and remains as a low value by-product at the end of the process. Fractionating this residue and adding value to its components would enhance the efficiency economics and ultimately sustainability of biorefining. One relatively abundant and easily recoverable chemical in the non-fermented material is the secondary metabolite ferulic acid, a phenylpropanoid (PP) used extensively in plants for making biologically active polyphenolic compounds. In this project we propose to use ferulic acid and other PPs as precursors to produce dihydrochalcones and their glycosylated derivatives through fermentation in metabolically engineered yeast. These dihydrochalcones are widely used as artificial sweetners and flavour masking agents in the food industry and are currently made by non-chemical transformation methods. In our process, we will reconstruct pathways which function to produce polyphenolics in plants and engineer them into yeast, which on feeding with PPs will then produce these artificial flavouring agents through a sustainable biological process. As artificial flavouring agents, the use of genetic modification to produce these compounds will not affect their market value, as they are not 'natural' products. Furthermore, the modular assembly of our engineered pathway and the feeding of specific PP pre-cursors gives us the potential to produce novel dihydrochalcones which have the potential to be developed into new flavour enhancing products for the food industry. The programme therefore will therefore add value to existing fermentation processes which utilise plant material. In addition the process would also be highly compatible with processes aimed at deconstructing lignin, which is a major non-fermentable product derived from woody biomass composed of PP intermediates. Thus the project is both of immediate utility and establishes useful technologies of longer term value to the biorefining industries which have identified lignin deconstruction and the use of the respective products as a major future commercial opportunity.