Shmonova Ekaterina A, Savrasova Ekaterina A, Fedorova Elizaveta N, Doroshenko Vera G
Ajinomoto-Genetika Research Institute, 117545 Moscow, Russia.
Microorganisms. 2022 Jul 5;10(7):1357. doi: 10.3390/microorganisms10071357.
The production of 3,4-dihydroxybenzoic acid (3,4-DHBA or protocatechuate) is a relevant task owing to 3,4-DHBA's pharmaceutical properties and its use as a precursor for subsequent synthesis of high value-added chemicals. The microbial production of 3,4-DHBA using dehydroshikimate dehydratase (DSD) (EC: 4.2.1.118) has been demonstrated previously. DSDs from soil-dwelling organisms (where DSD is involved in quinate/shikimate degradation) and from spp. (synthesizing the 3,4-DHBA-containing siderophore) were compared in terms of the kinetic properties and their ability to produce 3,4-DHBA. Catabolic DSDs from (QsuB) and (Qa-4) had higher K (1 and 0.6 mM, respectively) and k (61 and 220 s, respectively) than biosynthetic AsbF from (K0.04 mM, k1 s). Product inhibition was found to be a crucial factor when choosing DSD for strain development. AsbF was more inhibited by 3,4-DHBA (IC~0.08 mM), and MG1655 Δ P- strain provided only 0.2 g/L 3,4-DHBA in test-tube fermentation. Isogenic strains MG1655 Δ P- and MG1655 Δ P- expressing QsuB and Qa-4 with IC ~0.35 mM and ~0.64 mM, respectively, accumulated 2.7 g/L 3,4-DHBA under the same conditions.
由于3,4-二羟基苯甲酸（3,4-DHBA或原儿茶酸）具有药物特性且可用作后续合成高附加值化学品的前体，其生产是一项重要任务。先前已证明利用脱氢莽草酸脱水酶（DSD）（EC：4.2.1.118）通过微生物生产3,4-DHBA。对来自土壤栖息生物（其中DSD参与奎尼酸/莽草酸降解）和来自某属（合成含3,4-DHBA的铁载体）的DSD在动力学特性及其产生3,4-DHBA的能力方面进行了比较。来自某菌（QsuB）和某菌（Qa-4）的分解代谢DSD的K值（分别为1和0.6 mM）和k值（分别为61和220 s）高于来自某菌的生物合成AsbF（K0.04 mM，k1 s）。发现产物抑制是选择用于菌株开发的DSD时的一个关键因素。AsbF受3,4-DHBA的抑制作用更强（IC0.08 mM），并且MG1655 ΔP-菌株在试管发酵中仅产生0.2 g/L的3,4-DHBA。分别表达IC约为0.35 mM和0.64 mM的QsuB和Qa-4的同基因菌株MG1655 ΔP-和MG1655 ΔP-在相同条件下积累了2.7 g/L的3,4-DHBA。
