Combinatorial assembly platform enabling engineering of genetically stable metabolic pathways in cyanobacteria

Taylor, George M.; Hitchcock, Andrew; Heap, John T

Abstract

Cyanobacteria are simple, efficient, genetically-tractable photosynthetic microorganisms which in principle represent ideal biocatalysts for CO2 capture and conversion. However, in practice, genetic instability and low productivity are key, linked problems in engineered cyanobacteria. We took a massively parallel approach, generating and characterising libraries of synthetic promoters and RBSs for the cyanobacterium Synechocystis sp. PCC 6803, and assembling a sparse combinatorial library of millions of metabolic pathway-encoding construct variants. Genetic instability was observed for some variants, which is expected when variants cause metabolic burden. Surprisingly however, in a single combinatorial round without iterative optimisation, 80% of variants chosen at random and cultured photoautotrophically over many generations accumulated the target terpenoid lycopene from atmospheric CO2, apparently overcoming genetic instability. This large-scale parallel metabolic engineering of cyanobacteria provides a new platform for development of genetically stable cyanobacterial biocatalysts for sustainable light-driven production of valuable products directly from CO2, avoiding fossil carbon or competition with food production.

Citation

Taylor, G. M., Hitchcock, A., & Heap, J. T. (2021). Combinatorial assembly platform enabling engineering of genetically stable metabolic pathways in cyanobacteria. Nucleic Acids Research, 49(21), e123-e123. https://doi.org/10.1093/nar/gkab791

• Journal Article Type: Article
• Acceptance Date: Aug 28, 2021
• Online Publication Date: Sep 23, 2021
• Publication Date: Dec 2, 2021
• Deposit Date: Sep 9, 2021
• Publicly Available Date: Sep 23, 2021
• Journal: Nucleic Acids Research
• Print ISSN: 0305-1048
• Electronic ISSN: 1362-4962
• Publisher: Oxford University Press
• Peer Reviewed: Peer Reviewed
• Volume: 49
• Issue: 21
• Pages: e123-e123
• DOI: https://doi.org/10.1093/nar/gkab791
• Keywords: Genetics
• Public URL: https://nottingham-repository.worktribe.com/output/6189036
• Publisher URL: https://academic.oup.com/nar/advance-article/doi/10.1093/nar/gkab791/6374482