Construction of an alternative glycerol-utilization pathway for improved beta-carotene production in Escherichia coli
Construction of an alternative glycerol-utilization pathway for improved beta-carotene production in Escherichia coli
复制标题
构建替代甘油利用途径以提高大肠杆菌中β-胡萝卜素的产量
DOI：
10.1007/s10295-018-2045-1
复制
发表时间：
2018
影响因子：
3.4
通讯作者：
Zhang Xue-Li
中科院分区：
文献类型：
--
作者：
Guo Jin-Ying;Hu Kun-Le;Bi Chang-Hao;Li Qing-Yan;Zhang Xue-Li
甘油是生物柴油生产中不可避免的副产物，由于其价格低廉、可获得性好和化学还原状态，是生产类胡萝卜素的理想碳源，这导致对额外还原当量的需求较低。本研究构建了一条碳源利用途径，使大肠杆菌能够更有效地利用甘油生产β-胡萝卜素。将来自Ralstonia eutrophaH 16的醛还原酶基因（alrd）和醛脱氢酶基因（aldH）整合到E. colichromosome形成一个新的甘油利用途径。β-胡萝卜素的比生产值在引入alrdandaldH后提高了50%。发现甘油激酶基因（garK）alrdandaldH是甘油代谢途径的瓶颈，通过mRS文库调控garK基因可使β-胡萝卜素比产量提高13%。最后，通过aldH-alrd操纵子基因的共调控，β-胡萝卜素的比生产值比没有甘油利用途径的菌株提高了86%，甘油利用率也有所提高。本研究对E.通过构建和优化替代甘油利用途径，显著提高了大肠杆菌的产量。该策略可潜在地用于使用甘油作为廉价且丰富的底物来改善其它类异戊二烯的生产，因此具有工业相关性。
Glycerol, which is an inevitable by-product of biodiesel production, is an ideal carbon source for the production of carotenoids due to its low price, good availability and chemically reduced status, which results in a low requirement for additional reducing equivalents. In this study, an alternative carbon-utilization pathway was constructed inEscherichia colito enable more efficient β-carotene production from glycerol. An aldehyde reductase gene (alrd) and an aldehyde dehydrogenase gene (aldH) fromRalstonia eutrophaH16 were integrated into theE. colichromosome to form a novel glycerol-utilization pathway. The β-carotene specific production value was increased by 50% after the introduction ofalrdandaldH. It was found that the glycerol kinase gene (garK),alrdandaldHwere the bottleneck of the alternative glycerol metabolic pathway, and modulation ofgarKgene with an mRS library further increased the β-carotene specific production value by 13%. Finally, co-modulation of genes in the introduced aldH–alrd operon led to 86% more of β-carotene specific production value than that of the strain without the alternative glycerol-utilization pathway and the glycerol-utilization rate was also increased. In this work, β-carotene production ofE. coliwas significantly improved by constructing and optimizing an alternative glycerol-utilization pathway. This strategy can potentially be used to improve the production of other isoprenoids using glycerol as a cheap and abundant substrate, and therefore has industrial relevance.