Fermentative production of monomeric phenylpropanoids

单体苯丙素的发酵生产

• 批准号: 299511745
• 负责人: Dr. Kristina Haslinger
• 金额: --
• 依托单位: Department of Chemical Engineering
• 依托单位国家: 德国
• 项目类别: Research Fellowships
• 财政年份: 2016
• 资助国家: 德国
• 起止时间: 2015-12-31 至 无数据
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/299511745?language=en
• 关键词: Fermentative; production; monomeric; phenylpropanoids

Sustainable synthesis of valuable chemicals is often dependent on plant natural products such as the phenylpropanoids. The building blocks are mainly derived from decomposition of plant material, a costly and energy-demanding process. With the advance of genetic engineering of microbes, new routes have emerged relying on de novo biosynthesis in microbial hosts. However, these processes need years of bioengineering to obtain high product yields. Such bottom-up synthesis of monomeric phenylpropanoids as building blocks for the chemical industry has recently become achievable by establishing the initial steps of a synthetic pathway in microbes. The yield and diversity of products obtained are, however, still lagging behind the natural biosynthetic pathways found in plants. The project aims to expand the power of this synthetic pathway by engineering approaches on various levels: the availability of precursors, the efficiency of individual catalytic steps and the diversification of the product range. Since the established pathway depends on the availability of L-tyrosine, microbial hosts will be screened for improved performance on species and strain level, in particular strains of the traditional workhorse for industrial amino acid production, Corynebacterium glutamicum, designed to overproduce aromatic amino acids. The efficiency of the following catalytic steps is then going to be enhanced by screening for alternative enzymes and enzyme constructs. In particular for the Cytochrome P450-catalyzed step, modular tethering strategies with interacting redox enzymes will be developed that can also be applied to other pathways and thus provide means to overcome low enzyme activity, often a major hurdle in pathway design. In addition, downstream processing of the monomeric precursors by methylation will be established to finally provide a broad range of natural monolignols via microbial fermentation. Therefore, a range of O-methyltransferases from various organisms is going to be functionally characterized to gain insight into this crucial product tailoring step for pathway engineering projects in general and the phenylpropanoid pathway in particular. Lastly, a CRISPR/Cas9-based genome-editing system will be developed for C. glutamicum to facilitate the stable integration of pathways into this model organism and to increase its value for pathway engineering. The proposed study will not only increase the efficiency of the synthetic phenylpropanoid pathway but provide tools to further our abilities in manipulating microbial hosts for the fermentative production of valuable chemicals.

有价值化学品的可持续合成通常依赖于植物天然产物，如苯丙素类。建筑材料主要来自植物材料的分解，这是一个昂贵且耗能的过程。随着微生物基因工程的发展，依靠微生物宿主从头生物合成的新途径不断出现。然而，这些过程需要多年的生物工程来获得高的产品产量。这种自下而上的单体苯丙素类化合物的合成作为化学工业的结构单元，最近已成为通过建立微生物中的合成途径的初始步骤来实现的。然而，所获得的产品的产量和多样性仍然落后于植物中发现的天然生物合成途径。该项目旨在通过在各个层面上的工程方法来扩大这一合成途径的力量：前体的可用性，单个催化步骤的效率和产品范围的多样化。由于已建立的途径取决于L-酪氨酸的可用性，因此将筛选微生物宿主以在物种和菌株水平上改善性能，特别是用于工业氨基酸生产的传统主力菌株谷氨酸棒杆菌（Corynebacterium glutamicum），其被设计为过量生产芳香族氨基酸。随后的催化步骤的效率将通过筛选替代酶和酶构建体来增强。特别是对于细胞色素P450催化的步骤，将开发具有相互作用的氧化还原酶的模块化拴系策略，其也可以应用于其他途径，从而提供克服低酶活性的手段，这通常是途径设计中的主要障碍。此外，将建立通过甲基化对单体前体的下游加工，以最终通过微生物发酵提供广泛的天然单木质醇。因此，一系列的O-甲基转移酶从各种生物体的功能特性，以深入了解这一关键的产品定制步骤的途径工程项目一般和苯丙烷途径，特别是。最后，将为C开发基于CRISPR/Cas9的基因组编辑系统。谷氨酸杆菌，以促进途径稳定整合到该模式生物中，并增加其对途径工程的价值。拟议的研究不仅将提高合成苯丙烷途径的效率，而且还将提供工具，进一步提高我们操纵微生物宿主发酵生产有价值化学品的能力。