Professor Huang Jianzhong’s team from the Engineering Center of Industrial Microbiology, Ministry of Education, Fujian Normal University, Fujian Normal University, Associate Professor Qi Feng, etc. published in the journal of Agricultural and Food Chemistry (SCI Area 1, Top, IF=4.192) in the field of food and agricultural engineering technology The research paper titled”High-level production of indole-3-acetic acid in the metabolically engineered Escherichia coli”. In this study, the author first reported the establishment of two new IAA microbial synthesis pathways in E. coli cells:tryptamine (TAM) and indole-3-acetamide (IAM) pathways, and through whole-cell catalysis and de novo The method of biosynthesis realizes the high-yield IAA of recombinant E. coli MG1655.
Indole-3-acetic acid is an important chemical substance used by plants to regulate growth, development and physiological activities. IAA can stimulate and regulate many physiological reactions in plants, and auxin can also regulate plants through interaction with other hormones. Repair and other physiological activities. However, the amount of IAA extracted from plants or their endophytic strains is very small, which is difficult to meet the requirements of modern agricultural production. In this paper, using the strategy of metabolic engineering, the indole-3 of synthetic IAA was constructed by co-expression of the iaaM gene from Pseudomonas savastanoi and the ami1 gene from Arabidopsis thaliana. -Acetamide (IAM) pathway; At the same time, the tdc gene from Catharanthus roseus, the aoc1 gene from Aspergillus niger and the iad1 gene from Ustilago maydis were jointly constructed to construct the TAM pathway to synthesize IAA . In addition, this article also constructed a de novo synthesis (de novo) pathway that can use glucose to produce IAA, and optimize the supply and balance of intracellular reduction cofactors NADH and NADPH through Crispr/Cas9 technology to obtain de novo synthesis of IAA High-yielding E. coli strain. When 10 g/L L-tryptophan was used as the substrate, the MIA-6 strain containing the heterologous IAM pathway had the highest IAA yield, reaching 7.10g/L (1.34×103mg/gDCW), which is the whole cell catalyzing the TAM pathway 98.4 times; In addition, the de novo synthesis pathway of IAA was optimized by increasing the utilization rate of NAD(P)H. Finally, the recombinant strain MGΔadhE::icd used glucose as a substrate, and the yield of IAA was increased to 906 mg/L. In this paper, E. coli is used as a cell factory to express the IAM pathway and the TAM pathway to produce IAA, which provides a new idea for the research on the efficient use of microbial cells to produce amino acid derivatives.
Associate Professor Qi Feng and Professor Huang Jianzhong from the Engineering Center of the College of Life Sciences of Fujian Normal University are the co-corresponding authors of the paper, and the Engineering Center of Industrial Microbiology of the Ministry of Education of Fujian Normal University and the Key Laboratory of Cellular Stress Response and Metabolic Regulation of the College of Life Sciences are the communication unit. 2018 graduate student Hongxuan Wu and 2019 graduate student Jinhua Yang are the co-first authors. This research was funded by the National Natural Science Foundation of China and the Xiyuanjiang Scholars Program of the College of Life Sciences, Fujian Normal University.
Full text link:https://pubs.acs.org/doi/10.1021/acs.jafc.0c08141