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Motomura K, Sano K, Watanabe S, Kanbara A, Gamal Nasser AH, Ikeda T, Ishida T, Funabashi H, Kuroda A, Hirota R. Synthetic Phosphorus Metabolic Pathway for Biosafety and Contamination Management of Cyanobacterial Cultivation. ACS Synth Biol 2018; 7:2189-2198. [PMID: 30203964 DOI: 10.1021/acssynbio.8b00199] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Recent progress in genetic engineering and synthetic biology have greatly expanded the production capabilities of cyanobacteria, but concerns regarding biosafety issues and the risk of contamination of cultures in outdoor culture conditions remain to be resolved. With this dual goal in mind, we applied the recently established biological containment strategy based on phosphite (H3PO3, Pt) dependency to the model cyanobacterium Synechococcus elongatus PCC 7942 ( Syn 7942). Pt assimilation capability was conferred on Syn 7942 by the introduction of Pt dehydrogenase (PtxD) and hypophosphite transporter (HtxBCDE) genes that allow the uptake of Pt, but not phosphate (H3PO4, Pi). We then identified and disrupted the two indigenous Pi transporters, pst (Synpcc7942_2441 to 2445) and pit (Synpcc7942_0184). The resultant strain failed to grow on any media containing various types of P compounds other than Pt. The strain did not yield any escape mutants for at least 28 days with a detection limit of 3.6 × 10-11 per colony forming unit, and rapidly lost viability in the absence of Pt. Moreover, growth competition of the Pt-dependent strain with wild-type cyanobacteria revealed that the Pt-dependent strain could dominate in cultures containing Pt as the sole P source. Because Pt is rarely available in aquatic environments this strategy can contribute to both biosafety and contamination management of genetically engineered cyanobacteria.
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Affiliation(s)
- Kei Motomura
- Department of Molecular Biotechnology, Graduate School of Advanced Sciences of Matter, Hiroshima University, Higashi-Hiroshima, Hiroshima 739-8530, Japan
- Advanced Low Carbon Technology Research and Development Program, Japan Science and Technology Agency (JST-ALCA), Chiyoda-ku, Tokyo 102-0076, Japan
| | - Kosuke Sano
- Department of Molecular Biotechnology, Graduate School of Advanced Sciences of Matter, Hiroshima University, Higashi-Hiroshima, Hiroshima 739-8530, Japan
| | - Satoru Watanabe
- Advanced Low Carbon Technology Research and Development Program, Japan Science and Technology Agency (JST-ALCA), Chiyoda-ku, Tokyo 102-0076, Japan
- Department of Bioscience, Tokyo University of Agriculture, Tokyo 156-8502, Japan
| | - Akihiro Kanbara
- Department of Molecular Biotechnology, Graduate School of Advanced Sciences of Matter, Hiroshima University, Higashi-Hiroshima, Hiroshima 739-8530, Japan
| | - Abdel-Hady Gamal Nasser
- Department of Molecular Biotechnology, Graduate School of Advanced Sciences of Matter, Hiroshima University, Higashi-Hiroshima, Hiroshima 739-8530, Japan
| | - Takeshi Ikeda
- Department of Molecular Biotechnology, Graduate School of Advanced Sciences of Matter, Hiroshima University, Higashi-Hiroshima, Hiroshima 739-8530, Japan
| | - Takenori Ishida
- Department of Molecular Biotechnology, Graduate School of Advanced Sciences of Matter, Hiroshima University, Higashi-Hiroshima, Hiroshima 739-8530, Japan
| | - Hisakage Funabashi
- Department of Molecular Biotechnology, Graduate School of Advanced Sciences of Matter, Hiroshima University, Higashi-Hiroshima, Hiroshima 739-8530, Japan
| | - Akio Kuroda
- Department of Molecular Biotechnology, Graduate School of Advanced Sciences of Matter, Hiroshima University, Higashi-Hiroshima, Hiroshima 739-8530, Japan
- Advanced Low Carbon Technology Research and Development Program, Japan Science and Technology Agency (JST-ALCA), Chiyoda-ku, Tokyo 102-0076, Japan
| | - Ryuichi Hirota
- Department of Molecular Biotechnology, Graduate School of Advanced Sciences of Matter, Hiroshima University, Higashi-Hiroshima, Hiroshima 739-8530, Japan
- Advanced Low Carbon Technology Research and Development Program, Japan Science and Technology Agency (JST-ALCA), Chiyoda-ku, Tokyo 102-0076, Japan
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