Hydrogen Peroxide Inhibits the Growth of Cyanobacteria

V. D. Samuilov^*, D. V. Bezryadnov, M. V. Gusev, A. V. Kitashov, and T. A. Fedorenko

Department of Cell Physiology and Immunology, School of Biology, Lomonosov Moscow State University, Moscow, 119899 Russia; fax: (095) 939-3807

^* To whom correspondence should be addressed.

Received July 17, 1998; Revision received July 27, 1998

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H₂O₂ at concentrations of 10^-5-10^-4 M suppresses phototrophic growth of Anacystis nidulans and Anabaena variabilis in dialysis culture. The growth of the cyanobacteria resumed after a long adaptation period. In batch cultures, the growth of A. nidulans and A. variabilis was suppressed after one-time addition of 10^-2 and 10^-3-10^-2 M H₂O₂, respectively. Inducing intracellular H₂O₂ formation by adding methylviologen, vitamin K₃, or phenazine methosulfate suppresses the growth of both cyanobacteria. The catalase inhibitor salicylic acid suppresses the growth of A. nidulans and A. variabilis at a concentration of 5·10^-3 M. The data suggest an inhibitory effect of H₂O₂ on the growth of the cyanobacteria. H₂O₂ is unlikely to serve as an electron donor during photosynthesis.

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KEY WORDS: photosynthesis, water-oxidizing complex, photosystem II, photosynthetic oxygen, hydrogen peroxide, cyanobacteria, Anacystis nidulans, Anabaena variabilis

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