State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, 200240, China.
National Experimental Teaching Center for Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, 200240, China.
World J Microbiol Biotechnol. 2020 Mar 10;36(3):49. doi: 10.1007/s11274-020-02824-3.
Glycerol is a by-product of biodiesel, and it has a great application prospect to be transformed to synthesize high value-added compounds. Pseudomonas chlororaphis GP72 isolated from the green pepper rhizosphere is a plant growth promoting rhizobacteria that can utilize amount of glycerol to synthesize phenazine-1-carboxylic acid (PCA). PCA has been commercially registered as "Shenqinmycin" in China due to its characteristics of preventing pepper blight and rice sheath blight. The aim of this study was to engineer glycerol utilization pathway in P. chlororaphis GP72. First, the two genes glpF and glpK from the glycerol metabolism pathway were overexpressed in GP72ANO separately. Then, the two genes were co-expressed in GP72ANO, improving PCA production from 729.4 mg/L to 993.4 mg/L at 36 h. Moreover, the shunt pathway was blocked to enhance glycerol utilization, resulting in 1493.3 mg/L PCA production. Additionally, we confirmed the inhibition of glpR on glycerol metabolism pathway in P. chlororaphis GP72. This study provides a good example for improving the utilization of glycerol to synthesize high value-added compounds in Pseudomonas.
甘油是生物柴油的副产品，具有很大的应用前景，可以转化为合成高附加值的化合物。从青椒根际分离到的假单胞菌 GP72 是一种植物促生根瘤菌，可以利用大量的甘油来合成吩嗪-1-羧酸（PCA）。PCA 因其防治辣椒疫病和稻瘟病的特点，在中国已被商业注册为“申嗪霉素”。本研究旨在对 GP72 中的甘油利用途径进行工程改造。首先，在 GP72ANO 中分别过表达甘油代谢途径中的两个基因 glpF 和 glpK。然后，在 GP72ANO 中共表达这两个基因，将 PCA 的产量从 36 小时的 729.4mg/L 提高到 993.4mg/L。此外，还阻断了分流途径以增强甘油的利用，导致 PCA 的产量达到 1493.3mg/L。此外，我们还证实了 glpR 对 GP72 中甘油代谢途径的抑制作用。本研究为提高假单胞菌利用甘油合成高附加值化合物提供了一个很好的范例。
