利用大肠杆菌细胞工厂生产吲哚-3-乙酸的研究

目的:利用重组大肠杆菌全细胞转化色氨酸生产IAA.方法:在大肠杆菌胞内构建两条全新的IAA合成途径,即吲哚-3-乙酰胺(indole-3-acetamide,IAM)途径和色胺(tryptamine,TRP)途径.结果:IAM途径涉及两个酶,分别是色氨酸-2-单加氧酶(IAAM)和酰胺酶(AMI1),构建好的重组大肠杆...

Study on the Production of Indole-3-acetic Acid Using E. coli Cell Factory

Objective:Indole-3-acetic acid(IAA)was produced from tryptophan in the metabolically engineered E.coli MG1655 using whole-cell catalysis.Methods:Two novel IAA biosynthetic pathways,the indole-3-acetamide(IAM)pathway and the tryptamine(TRP)pathway,were constructed in E.coli MG1655.Results:The IAM pathway involves two enzymes,tryptophan-2-monooxygenase(IAAM)and amidase(AMI1).2 g/L tryptophan as a substrate was used by the constructed recombinant E.coli strain TPA-4.TPA-4 can produce 0.803 g/L of IAA;however,in the strain MPA-3 that was knocked out the gene tnaA which divert flux from tryptophan synthesis,the yield of IAA reached 1.43 g/L,an increase of 78% compared with the control.The second TRP pathway biosynthesis of IAA involves three enzymes:L-tryptophan decarboxylase(TDC),diamine oxidase(AOC1)and indole-3-acetaldehyde dehydrogenase(IAD1).The recombinant E.coli TPTA-2 that included the TRP pathway can only synthesize 13.0 mg/L IAA with 2 g/L tryptophan as substrate.In the strain MPTA-3 with disruption of tnaA gene,21.0 mg/L of IAA was finally produced,and the yield increased by 61.5%.Conclusion:It is the first report to realize production of IAA using the metabolically engineered E.coli through the IAM pathway and TRP pathway via whole-cell catalysis.IAA production from the IAM pathway is relatively higher,and it probably has an industrial application prospect.