使用逆β-氧化 (rBOX) 途径为选择性1-十醇生产的工程大肠杆菌
1Department of Chemical, Biological and Materials Engineering, University of South Florida, Tampa, FL, USA.
Metabolic engineering
|July 23, 2023
概括
通过逆β-氧化 (rBOX) 途径,工程化大肠杆菌产生1-十醇. 实现了高位数和产量,证明了工业酒精生产的潜力.
科学领域:
- 代谢工程是代谢工程.
- 合成生物学 合成生物学
- 生物技术是生物技术.
背景情况:
- 1-Decanol是一种有价值的化学物质,在制药,香水和更广泛的化学工业中具有应用.
- 对于工业的可持续性来说,1-decanol的高效和选择性的微生物生产是可取的.
- 现有的1 - 甲醇合成方法经常面临产量,标位和特异性的挑战.
研究的目的:
- 为了设计大肠杆菌为选择性生物合成的1-decanol.
- 为了优化反向β氧化 (rBOX) 路径和终端模块,以高效地生产1-十醇醇.
- 通过代谢工程策略和发酵优化来增强1-十醇的生产.
主要方法:
- 使用核心逆β氧化 (rBOX) 途径和特定终结酶的工程大肠杆菌.
- 选乙基-CoA减少酶终结酶和调节rBOX通路的表达.
- 代谢工程包括pyruvate异样化优化 (pyruvate脱酶) 和铁酶淘汰 (YigI).
- 双相发酵与多德干覆盖,以减轻毒性和增强运输.
- 途径表达的优化,细胞生长条件 (氧气可用性) 和介质组成 (丰富与最小).
主要成果:
- 获得了1.4g/L的初始1-decanol标位,通过进一步的工程改进到1.9g/L.
- 双相发酵在36小时内产生了4.4g/L的1-decanol (0.21g/g的产量).
- 优化条件导致在摇瓶中产生6.1 g/L (0.26 g/g收益率),在生物反应器中使用丰富介质产生10.05 g/L (0.2 g/g收益率).
- 最小的基质发酵达到2.8g/L (0.14g/g收益率) 的100%的特异性.
- 取得的标位,产量和纯度明显高于之前报告的 (至少是10倍).
结论:
- 改造的大肠杆菌菌株显示出对工业规模生产1-decanol的巨大潜力.
- 将rBOX路径与特定的终结酶和底盘工程相结合,是选择性酒精生产的有效策略.
- 开发的代谢工程和发酵方法为生产有价值的长链酒精提供了强大的平台.
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