Simulated growth rates and proton fluxes through ATPases for Escherichia coli MG1655 and Synechocystis sp. PCC6803

Range Table - link
Organism bacteria
Reference Claassens NJ, Volpers M, dos Santos VA, van der Oost J, de Vos WM. Potential of proton-pumping rhodopsins: engineering photosystems into microorganisms. Trends Biotechnol. 2013 Nov31(11):633-42. doi: 10.1016/j.tibtech.2013.08.006. p.639 table 2PubMed ID24120288
Primary Source [54] Orth JD et al., A comprehensive genome-scale reconstruction of Escherichia coli metabolism2011. Mol Syst Biol. 2011 Oct 11 7: 535. doi: 10.1038/msb.2011.65. [58] Nogales, J. et al. (2013) Detailing the optimality of photosynthesis in cyanobacteria through systems biology analysis. Proc. Natl. Acad. Sci. U.S.A. 109, 2678–2683 doi: 10.1073/pnas.1117907109.PubMed ID21988831, 22308420
Method See 2nd column from right in table
Comments p.638 right column bottom paragraph:"In E. coli in which a proteorhodopsin has been introduced, increased ATP synthesis is demonstrated in light and in the absence of oxidative phosphorylation [ref 5]. The increased cellular ATP level from photophosphorylation has been measured, but this ATP increase is about four times lower than that from oxidative phosphorylation [ref 5]. For further quantitative comparison of PPR [proton-pumping rhodopsin] proton fluxes with respiratory proton fluxes, [investigators] have simulated standard aerobic growth on glucose (10 mM/g dry weight/h) of E. coli in a genome-scale metabolic reconstruction by performing a flux balance analysis [primary source 54, ref 55]. In this simulation, the predicted respiratory proton flux through the ATPase is ~22 times higher than [investigators’] estimate for a feasible PPR proton flux (Tables 1 [BNID 111309] and 2). When this estimated PPR proton flux is included in the simulation of aerobic growth of E. coli, a growth rate increase of only 2% is predicted (Table 2). Correspondingly, E. coli engineered with PPRs does not exhibit increased growth, whereas P. putida engineered with a PPR does increase aerobic growth rates in light, but only at low carbon substrate concentrations (J.D. Buck, PhD thesis, MIT, 2012)."
Entered by Uri M
ID 111699