Photo-induction of electrical current with the cyanobacteriumAgmenellum quadruplicatum PR-6
We investigated the possibility of eliciting a measurable photoinduced electrical current from the cyanobacteriumAgmenellum quadruplicatum PR-6 (Synechococcus PCC 7002). This proved virtually impossible for intact cells. However, treated PR-6 cells fixed in an alginate matrix on tin oxide as the active electrode in a three electrode electrochemical cell gave rise to a significant light response. Cell treatments involving toluene, chloroform or detergents were effective and gave current responses up to 250 nA. Drying the cyanobacterial matrix increased the current yield at least fifty-fold. These effects were observed for light wavelengths > 650 nm and were not influenced by inhibitors or enhancers of photosynthesis nor by sustained argon bubbling of the electrolyte.
French pressure cell lysates facilitated distinction between two light induced current components. Lysates prepared without CaCl2 gave current induction kinetics that were indistinguishable from those on chemically treated cells i.e. slowly rising to a stable maximum in 10–15 min. When CaCl2 was present during lysis, a rapidly induced (<1 s) unstable component was observed. Toluenization of PR-6 either prior to or post lysing abolished the CaCl2 related effect. CaCl2 had no effect on current induction in strain PR-6008, which lacked the α and β subunits of phycocyanin and exhibited slow current induction kinetics.
The observed effects are interpreted as responses of components of the photosystems of PR-6 rather than in terms of an integrated photosynthetic process.
Key wordsAgmenellum quadruplicatum Synechococcus 7002 cyanobacteria photo-induced current electrochemical cell alignate thin film
- chl a
saturated calomel electrode
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- de Lorimier R, Bryant DA, Porter RD, Liu W-Y, Jay E, Stevens Jr SE (1984) Genes for the α and β subunits of phycocyanin. Proc. Natl. Acad. Sci. (USA) 81: 7946–7950.Google Scholar
- Haenel W, Heupel A, Hengstermann D (1978) Investigations on a galvanic cell driven by photosynthetic electron transport. Z. Naturforsch. Teil C 33: 392–401.Google Scholar
- Ho KK, Krogmann DW (1982) Photosynthesis In Carr NG, Whitton BA (eds), The Biology of Cyanobacteria, pp. 191–214. Blackwell Scientific Publications, Oxford.Google Scholar
- Janzen AF, Bolton JR (1979) Photochemical electron transfer in monolayer assemblies: 1. spectroscopic study of radicals produced in chlorophyll a/acceptors systems. J. Am. Chem. Soc. 101: 6337–6341.Google Scholar
- Janzen AF, Seibert M (1980) Photoelectrochemical conversion using reaction-centre electrodes. Nature 286: 584–585.Google Scholar
- Miyasaka TT, Watanabe A, Fujishima A, Honda K (1978) Light energy conversion with chlorophyll monolayer electrodes.In vitro electrochemical simulation of photosynthetic primary processes. J. Am. Chem. Soc. 100: 6657–6665.Google Scholar
- Miyasaka TT, Watanabe A, Fujishima A, Honda K (1979) Highly efficient quantum conversion at chlorophyll a-lecithin mixed monolayer coated electrodes. Nature 227: 638–640.Google Scholar
- Ochiai H, Shibata H, Fujishima A, Honda K (1979) Photocurrent by immobilized chloroplast film electrode. Agric. Biol. Chem. 43: 881–883.Google Scholar
- Ochiai H, Shibata H, Sawa Y, Katoh T (1980) ‘Living electrode’ as a long-lived photoconverter for biophotolysis of water. Proc. Natl. Acad. Sci (USA) 77: 2442–2444.Google Scholar
- Ochiai H, Shibata H, Sawa Y, Katoh T (1982) Properties of the chloroplast film electrode immobilized on an SnO2-coated glass plate. Photochem. Photobiol. 35: 149–155.Google Scholar
- Ochiai H, Shibata H, Sawa Y, Shoga M, Ochta S (1983) Properties of semiconductor electrodes coated with living films of cyanobacteria. Appl. Biochem. Biotechnol. 8: 289–303.Google Scholar
- Seibert M, Janzen AF, Kendall-Tobias MW (1982) Light-induced electron transport across semiconductor electrode/reaction-center film/electrolyte interfaces. Photochem. Photobiol. 35: 193–200.Google Scholar
- Seibert M, Kendall-Tobias MW (1982) Photoelectrochemical properties of electrodes coated with photoactive-membrane vesicles isolated from photosynthetic bacteria. Biochim. Biophys. Acta 681: 504–511.Google Scholar
- Stevens Jr SE, Van Baalen C (1970) Growth characteristics of selected mutants of a coccoid blue-green alga. Arch. Microbiol. 72: 1–8.Google Scholar
- Stevens Jr SE, Van Baalen C (1973) Characteristics of nitrate reduction in a mutant of the blue-green algaAgmenellum quadruplicatum Plant Physiol. 51: 350–356.Google Scholar
- Stevens Jr SE, Van Baalen C (1974) Control of nitrate reductase in a blue-green alga: the effects of inhibitors, blue-light, and ammonia. Arch. Biochem. Biophys. 161: 146–152.Google Scholar
- Stevens Jr SE, Porter RD (1980) Transformation inAgmenellum quadruplicatum. Proc. Natl. Acad. Sci. (USA) 77: 6052–6056.Google Scholar