ME: Collaborative Research: Metabolic Engineering of E. coli Sugar-Utilization Regulatory Systems for the Consumption of Plant Biomass Sugars

该项目的总体目标是对大肠杆菌糖利用调节系统(SURS)进行新陈代谢工程，以利用从植物生物质中获得的糖混合物。首席调查员(PI)将对SUR引入特定的基因修改，并在细胞水平上分析这些变化的后果。其具体目标是：(1)构建具有修饰的SURS的大肠杆菌菌株，并评估它们有效利用糖混合物(葡萄糖、木糖和阿拉伯糖)的能力；(2)评估基因表达调控在基因组水平上的变化；(3)利用一种新的基于2D核磁共振键标记实验的核苷酸分析的通量分析技术，识别SURS突变体和野生型菌株中的功能代谢途径，并量化它们的通量；(4)使用结合基因表达和代谢通量数据的基于遗传网络的代谢通量分析(MFA)模型来整合这些结果；以及(5)建议进一步进行遗传/环境改造，以提高SURS突变株发酵糖类混合物的能力。这个项目将带来两方面的好处。首先，从应用的角度来看，该项目将为设计合理的SURS修饰提供强有力的工具，以获得能够有效代谢糖混合物的重组菌株。其次，从根本上讲，这个项目将有助于更好地理解SURs在调节糖利用和其他几种细胞功能方面的作用。

The overall objective of this project is to metabolically engineer the E. coli Sugar-Utilization Regulatory Systems (SURS) to utilize sugar mixtures obtained from plant biomass. The Principal Investigators (PIs) will introduce specific genetic modifications to the SURS and analyze the consequences of these changes at the cellular level. The specific goals are to: (1) construct E. coli strains with modified SURS and evaluate their capability to efficiently utilize sugar mixtures (glucose, xylose and arabinose); (2) evaluate changes in the regulation of gene expression at the genomic scale resulting from engineering E. coli SURS; (3) identify functional metabolic pathways and quantify their fluxes in SURS mutants and wild type strains by using a novel flux analysis technique based on bondomer analysis of 2D NMR bond-labeling experiments; (4) integrate these results using a novel genetic network-based metabolic flux analysis (MFA) model that combines gene expression and metabolic flux data; and (5) propose further genetic/environmental modification for improving the capacity of SURS mutants for fermenting sugar mixtures. The benefits from this project will be two-fold. First, from an applied standpoint, the project will provide a powerful tool for designing of rational modifications of the SURS to obtain recombinant strains capable of efficiently metabolizing sugar mixtures. Second, from a fundamental standpoint, this project will contribute to a better understanding of the role of SURS in regulating both sugar utilization and several other cellular functions.