Wei Xin, Zhang Miao, Wang Guang-Yuan, Liu Guang-Lei, Chi Zhen-Ming, Chi Zhe
College of Marine Life Sciences, Ocean University of China, Yushan Road, No. 5, Qingdao, China.
College of Life Science, Shandong Province Key Laboratory of Applied Mycology, Qingdao Agricultural University, Qingdao, 266109, China.
Synth Syst Biotechnol. 2022 Oct 19;8(1):33-45. doi: 10.1016/j.synbio.2022.10.004. eCollection 2023 Mar.
The current petroleum chemical methods for fumaric acid production can cause heavy pollution and global warming. In this study, the engineered strains of var. were found to be suitable for green fumaric acid producer. Removal and complementation of the relevant genes showed only the ornithine-urea cycle (OUC) was involved in high level fumarate biosynthesis which was controlled by the Ca signaling pathway. Removal of both the gene encoding glucose oxidase and the gene encoding the polyketide synthase for 3,5-dihydroxydecanoic acid biosynthesis and overexpression of the gene encoding pyruvate carboxylase made the strain e-PYC produce 88.1 ± 4.3 g/L of fumarate at flask level and 93.9 ± 0.8 g/L of fumarate during the fed-batch fermentation. As a yeast-like fungal strain, it was very easy to cultivate var. DH177 and their mutants in the bioreactor and to edit its genomic DNAs to enhance fumarate production. It was found that 2 mol of CO could be fixed during a maximal theoretical yield of 2 mol of fumarate per mole of glucose consumed in the OUC. Therefore, the OUC-mediated fumarate biosynthesis pathway in var. was a green and eco-friendly process for the global sustainable development and carbon neutrality.
目前用于生产富马酸的石油化学方法会造成严重污染并导致全球变暖。在本研究中，发现工程菌株适合作为绿色富马酸生产者。相关基因的去除和互补表明，只有鸟氨酸-尿素循环（OUC）参与了由钙信号通路控制的高水平富马酸生物合成。去除编码葡萄糖氧化酶的基因和编码用于3,5-二羟基癸酸生物合成的聚酮合酶的基因，并过表达编码丙酮酸羧化酶的基因，使得菌株e-PYC在摇瓶水平下产生88.1±4.3 g/L的富马酸，在分批补料发酵过程中产生93.9±0.8 g/L的富马酸。作为一种酵母样真菌菌株，在生物反应器中培养DH177及其突变体并编辑其基因组DNA以提高富马酸产量非常容易。发现在OUC中，每消耗1摩尔葡萄糖最大理论产量为2摩尔富马酸的过程中可以固定2摩尔CO₂。因此，OUC介导的富马酸生物合成途径是一个有利于全球可持续发展和碳中和的绿色环保过程。
