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Engineered microorganisms such as the probiotic strain Escherichia coli Nissle 1917 (EcN) offer a strategy to sense and modulate the concentration of metabolites or therapeutics in the gastrointestinal tract. Here, we present an approach to regulate the production of the depression-associated metabolite gamma-aminobutyric acid (GABA) in EcN using genetic circuits that implement negative feedback. We engineered EcN to produce GABA by overexpressing glutamate decarboxylase and applied an intracellular GABA biosensor to identify growth conditions that improve GABA biosynthesis. We next employed characterized genetically encoded NOT gates to construct genetic circuits with layered feedback to control the rate of GABA biosynthesis and the concentration of GABA produced. Looking ahead, this approach may be utilized to design feedback control of microbial metabolite biosynthesis to achieve designable smart microbes that act as living therapeutics.
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Engineering living therapeutics and diagnostics: A new frontier in human health
Traditional therapeutics aim to diagnose, treat, and cure diseases through various synthetic and natural approaches. The emerging field of engineered living therapeutics (ELTs) genetically functionalizes living cells to alter the paradigm of designed solutions. In this review, we focus on ELTs derived from microbial cell scaffolds. We propose three synergistic modalities for the rational design of ELTs: first, use of regulatory operations to regulate genetic expression; second, integration of alternative biosensing inputs for directed application; third, choice of microbial chassis to deliver solutions. We highlight the challenges and future opportunities within each group and conclude by providing a prospective outlook for ELTs.
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- PAR ID:
- 10530222
- Publisher / Repository:
- Current Opinion in Systems Biology
- Date Published:
- Journal Name:
- Current Opinion in Systems Biology
- Volume:
- 37
- Issue:
- C
- ISSN:
- 2452-3100
- Page Range / eLocation ID:
- 100484
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
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Accepted Manuscript1.0
- Journal Article:
- https://doi.org/10.1016/j.coisb.2023.100484
