Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
6494174 | Metabolic Engineering | 2016 | 26 Pages |
Abstract
We introduced a plasmid (pCadCS) carrying genes for itaconic acid production into E. coli and applied a model-based approach to construct a high yield production strain. Based on the concept of minimal cut sets, we identified intervention strategies that guarantee high itaconic acid yield while still allowing growth. One cut set was selected and the corresponding genes were iteratively knocked-out. As a conceptual novelty, we pursued an adaptive approach allowing changes in the model and initially calculated intervention strategy if a genetic modification induces changes in byproduct formation. Using this approach, we iteratively implemented five interventions leading to high yield itaconic acid production in minimal medium with glucose as substrate supplemented with small amounts of glutamic acid. The derived E. coli strain (ita23: MG1655 âaceA âsucCD âpykA âpykF âpta âPicd::cam_BBa_J23115 pCadCS) synthesized 2.27Â g/l itaconic acid with an excellent yield of 0.77Â mol/(mol glucose). In a fed-batch cultivation, this strain produced 32Â g/l itaconic acid with an overall yield of 0.68Â mol/(mol glucose) and a peak productivity of 0.45Â g/l/h. These values are by far the highest that have ever been achieved for heterologous itaconic acid production and indicate that realistic applications come into reach.
Related Topics
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Authors
Björn-Johannes Harder, Katja Bettenbrock, Steffen Klamt,