Eliciting novel microbial phenotypes through transcriptional, degradation, and translational engineering

生物技术计划化学、生物工程、环境和运输系统司通过转录、降解和翻译工程获得新的微生物表型格雷戈里·斯蒂芬诺普洛斯麻省理工学院CBET-0730238这项研究的目标是选择转录和翻译机制的成员，以丰富全球调控器库，从而在原核细胞中诱导出原本无法达到的新的表型。将开发量化不同调节剂及其组合工程产生的文库多样性的方法，作为指导最有希望的候选调节剂的表型改进过程的手段。最后，一系列专门设计的实验将阐明突变调节器与宿主细胞的固有机制相互作用产生新的表型的机制。这项研究的智力价值在于促进了对转录机制及其与全球细胞内范围突变调节因子相互作用的基本理解。此外，它还将通过确定影响基因表达的直接和间接分子相互作用来阐明转录调控。也许最持久的影响将是认识到许多细胞表型是许多基因的集体属性，因此，应该通过更具创造性的方法来优化，而不是像这里提出的全球调控工程那样的单基因调控。这项研究的更广泛的影响是开辟了一条全新的、完全未被探索的、表型诱导和菌株改良的途径。当人们考虑到对有毒化合物耐受性的特定表型时，这一点尤其重要。作为一个模型系统，将研究大肠杆菌对乙醇和其他生物质水解有毒副产物的耐受性。通过设计更耐受的菌株，整个生物质转化为生物燃料的过程将得到实质性改善。目前因耐受性有限而受损的其他生物技术过程也同样可以从这项研究中受益。

Biotechnology ProgramDivision of Chemical, Bioengineering, Environmental, and Transport SystemsEliciting Novel Microbial Phenotypes through Transcriptional, Degradation, and Translational EngineeringGregory StephanopoulosMassachusetts Institute of TechnologyCBET-0730238The goal of this research is to select members of the transcription and translation machinery in order to enrich the repertoire of global regulators by which new, otherwise unreachable, phenotypes can be elicited in prokaryotic cells. Methods to quantify the diversity of libraries resulting from the engineering of various regulators and their combinations will be developed as means of guiding the phenotype improvement process to the most promising candidate regulators. Finally, a series of specially designed experiments will elucidate the mechanism by which mutant regulators interact with the native machinery of the host cell in eliciting the new phenotypes. The intellectual merit of this research lies in advancing the fundamental understanding of the transcription mechanism and its interaction with mutant regulators of global intracellular reach. Additionally, it will elucidate transcriptional regulation by identifying direct and indirect molecular interactions by which gene expression is affected. Perhaps the most lasting impact will be the realization that many cellular phenotypes are the collective property of many genes and, as such, should be optimized by more creative methods than single gene modulation, like global regulator engineering proposed herein. The broader impact of the research is the opening of a new, totally unexplored, avenue to phenotype elicitation and strain improvement. This is of particular importance when one considers the specific phenotypes of tolerance to toxic compounds. As a model system, tolerance of E. coli to ethanol and other toxic byproducts of biomass hydrolysis will be studied. By engineering more tolerant strains, an overall biomass-to-biofuels conversion process will be substantially improved. Other biotechnological processes presently impaired from limited tolerances could similarly benefit from this research.