The team of Professor Huang Jianzhong of Fujian Normal University first reported the establishment of two new pathways for IAA microbial synthesis within E. coli cells

Original title: Professor Huang Jianzhong of Fujian Normal University, Professor Qi Feng and other teachers published research papers in Journal of Agricultural and Food Chemistry
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A research paper entitled "High-level production of indole-3-acetic acid in the me
tabolically engineered Escherichia coli" was published. In this study, the authors first reported the establishment of two new pathways for IAA microbial synthesis within E. coli cells: the coloramine (TAM) and pyridine-3-acetylamide (IAM) pathways, and the recombination of E. coli MG1655 high-yield IAA through whole-cell catalysis and head-to-head biosynthesis.
-3-acetic acid is an important chemical used by plants to regulate growth and development and physiological activity, and IAA stimulates and regulates numerous physiological reactions in plants, while growth hormones can also regulate other physiological activities such as plant repair through interactions with other hormones. However, the amount of IAA extracted from plants or their endogenes is very small, which is difficult to meet the requirements of modern agricultural production. Using metabolic engineering strategies, this paper constructs a synthetic IAA pyridine-3-acetylamide (acetylamide) by co-expression of the iaaM gene from Pseudomo
nas savastanoi and the ami1 gene from Arabidopsis thaliana. IAM pathway, which also creates a TAM pathway to synthesize IAA from the tdc gene of Catharanthus roseus, the aoc1 gene from Aspergillus niger, and the Iard1 gene from Ustilago maydis. In addition, this paper also constructs a head-to-head synthesis (de novo) approach that can produce IAA using glucose, and optimizes the supply and balance of in-cell reduction cofactors NADH and NADPH through Crispr/Cas9 technology to obtain high-yielding E. coli strains that can synthesize IAA from the head. When 10 g/L L-tryptophan is the substrate, the MIA-6 strain containing the isogenetic IAM pathway has the highest IAA yield, reaching 7.10g/L (1.34×103mg/gDCW), which is all-cell catalysis 98.4 times the TAM pathway, and by improving the utilization rate of NAD(P)H to optimize the IAA from the beginning synthesis path, and finally recombinant strain MG-adhE::icd with glucose as the base, the resulting IAA yield increased to 906 mg/L. In this paper, E. coli as a cell factory exogenetic expression of IAM and TAM approach to the production of IAA work, for the efficient use of microbial cells to produce amino acid derivatives to provide a new way of thinking.
Associate Professor Qi Feng and Professor Huang Jianzhong of the Engineering Center of the School of Life Sciences of Fujian Normal University are co-authors of the paper, and the key laboratories of the University of Fujian Normal University, the Engineering Center of the Ministry of Industrial Microbiology and the School of Life Sciences, are the communication units. Wu Hongxuan, a 2018 graduate student, and Yang Jinhua, a 2019 graduate student, are co-authors. The research was funded by the National Natural Science Foundation of China and the Xiyuanjiang Scholars Program of the School of Life Sciences of Fujian Normal University.
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