A Glucose-Sensing Toggle Switch for Autonomous, High Productivity Genetic Control
A Glucose-Sensing Toggle Switch for Autonomous, High Productivity Genetic Control
复制标题
DOI：
10.1021/acssynbio.6b00257
复制
发表时间：
2017-07-01
影响因子：
4.7
通讯作者：
Tyo, Keith E. J.
中科院分区：
文献类型：
--
作者：
Bothfeld, William;Kapov, Grace;Tyo, Keith E. J.
许多生物合成策略与生长相结合，这是固有的限制，因为（1）过量的原料（例如，糖）可以转化为生物质而不是产物，（2）必须保持必需基因，和（3）必须控制生长毒性。分离的增长和生产阶段战略可以避免这些问题。我们开发了一种拨动开关，使用葡萄糖传感来实现这种两相策略。临时葡萄糖饥饿精确地和自主地激活丰富或基本培养基中的产物途径表达，避免了对昂贵诱导剂的需求。即使在重新引入葡萄糖之后，开关也稳定地保持在新状态。在聚羟基丁酸酯（PHB）生物合成的背景下，我们的系统能够实现更短的生长期和与组成型表达的PHB菌株相当的滴度。这种两阶段生产策略，特别是葡萄糖切换开关，应该广泛适用于启动许多类型的遗传程序的代谢工程应用。
Many biosynthetic strategies are coupled to growth, which is inherently limiting, as (1) excess feedstock (e.g., sugar) may be converted to biomass, instead of product, (2) essential genes must be maintained, and (3) growth toxicity must be managed. A decoupled growth and production phase strategy could avoid these issues. We have developed a toggle switch that uses glucose sensing to enable this two-phase strategy. Temporary glucose starvation precisely and autonomously activates product pathway expression in rich or minimal media, obviating the requirement for expensive inducers. The switch remains stably in the new state even after reintroduction of glucose. In the context of polyhydroxybutyrate (PHB) biosynthesis, our system enables shorter growth phases and comparable titers to a constitutively expressing PHB strain. This two-phase production strategy, and specifically the glucose toggle switch, should be broadly useful to initiate many types of genetic program for metabolic engineering applications.