Lu Nan, Zhang Chenglin, Zhang Wenjie, Xu Haoran, Li Yuhong, Wei Minhua, Meng Jing, Meng Yan, Wang Junzhe, Chen Ning
College of Biotechnology, Tianjin University of Science and Technology, Tianjin, China.
Front Bioeng Biotechnol. 2021 Nov 15;9:746322. doi: 10.3389/fbioe.2021.746322. eCollection 2021.
is one of the important industrial microorganisms for production of amino acids and other value-added compounds. Most expression vectors used in are based on inducible promoter (P or P ) activated by isopropyl-β-D-thiogalactopyranoside (IPTG). However, these vectors seem unsuitable for large-scale industrial production due to the high cost and toxicity of IPTG. Myo-inositol is an ideal inducer because of its non-toxicity and lower price. In this study, a myo-inositol-inducible expression vector pMI-4, derived from the expression vector pXMJ19, was constructed. Besides the original chloramphenicol resistance gene , multiple cloning sites, and terminator, the pMI-4 (6,643 bp) contains the cassette and the myo-inositol-inducible promoter P . The pMI-4 could stably replicate in the host. Meanwhile, the non-myo-inositol degradation host strain ΔΔΔΔ for maintaining the pMI-4 was developed. Overexpression of and using pMI-4 resulted in a significant accumulation of 5-aminolevulinic acid, indicating its potential application in metabolic engineering and industrial fermentation.
是生产氨基酸和其他增值化合物的重要工业微生物之一。大多数用于的表达载体基于由异丙基-β-D-硫代半乳糖苷（IPTG）激活的诱导型启动子（P或P）。然而，由于IPTG的高成本和毒性，这些载体似乎不适合大规模工业生产。肌醇因其无毒且价格较低而成为理想的诱导剂。在本研究中，构建了一种源自表达载体pXMJ19的肌醇诱导型表达载体pMI-4。除了原始的氯霉素抗性基因、多克隆位点和终止子外，pMI-4（6,643 bp）还包含盒式结构和肌醇诱导型启动子P。pMI-4可以在宿主中稳定复制。同时，开发了用于维持pMI-4的非肌醇降解宿主菌株ΔΔΔΔ。使用pMI-4过表达和导致5-氨基乙酰丙酸大量积累，表明其在代谢工程和工业发酵中的潜在应用。
