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Combining retinal-based and chlorophyll-based (oxygenic) photosynthesis: Proteorhodopsin expression increases growth rate and fitness of a ∆PSI strain of Synechocystis sp. PCC6803.
- Source :
-
Metabolic engineering [Metab Eng] 2019 Mar; Vol. 52, pp. 68-76. Date of Electronic Publication: 2018 Nov 14. - Publication Year :
- 2019
-
Abstract
- To fill the "green absorption gap", a green absorbing proteorhodopsin was expressed in a PSI-deletion strain (ΔPSI) of Synechocystis sp. PCC6803. Growth-rate measurements, competition experiments and physiological characterization of the proteorhodopsin-expressing strains, relative to the ΔPSI control strain, allow us to conclude that proteorhodopsin can enhance the rate of photoheterotrophic growth of ΔPSI Synechocystis strain. The physiological characterization included measurement of the amount of residual glucose in the spent medium and analysis of oxygen uptake- and production rates. To explore the use of solar radiation beyond the PAR region, a red-shifted variant Proteorhodopsin-D212N/F234S was expressed in a retinal-deficient PSI-deletion strain (ΔPSI/ΔSynACO). Via exogenous addition of retinal analogue an infrared absorbing pigment (maximally at 740 nm) was reconstituted in vivo. However, upon illumination with 746 nm light, it did not significantly stimulate the growth (rate) of this mutant. The inability of the proteorhodopsin-expressing ΔPSI strain to grow photoautotrophically is most likely due to a kinetic rather than a thermodynamic limitation of its NADPH-dehydrogenase in NADP <superscript>+</superscript> -reduction.<br /> (Copyright © 2018 International Metabolic Engineering Society. Published by Elsevier Inc. All rights reserved.)
- Subjects :
- Conjugation, Genetic genetics
Culture Media
Escherichia coli metabolism
Glucose metabolism
Light
NADPH Dehydrogenase metabolism
Oxygen metabolism
Rhodopsins, Microbial genetics
Synechocystis genetics
Chlorophyll metabolism
Photosynthesis genetics
Retinaldehyde metabolism
Rhodopsins, Microbial biosynthesis
Synechocystis metabolism
Subjects
Details
- Language :
- English
- ISSN :
- 1096-7184
- Volume :
- 52
- Database :
- MEDLINE
- Journal :
- Metabolic engineering
- Publication Type :
- Academic Journal
- Accession number :
- 30447329
- Full Text :
- https://doi.org/10.1016/j.ymben.2018.11.002