Hydrogen-oxidizing hydrogenases 1 and 2 of Escherichia coli regulate the onset of hydrogen evolution and ATPase activity, respectively, during glucose fermentation at alkaline pH

Authors

  • Anna Poladyan,

    1. Department of Microbiology, Plants and Microbes Biotechnology, Faculty of Biology, Yerevan State University, Yerevan, Armenia
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  • Karen Trchounian,

    1. Department of Biophysics, Faculty of Biology, Yerevan State University, Yerevan, Armenia
    2. Institute of Biology/Microbiology, Martin Luther University of Halle-Wittenberg, Halle, Germany
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  • R. Gary Sawers,

    1. Institute of Biology/Microbiology, Martin Luther University of Halle-Wittenberg, Halle, Germany
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  • Armen Trchounian

    Corresponding author
    1. Department of Microbiology, Plants and Microbes Biotechnology, Faculty of Biology, Yerevan State University, Yerevan, Armenia
    • Correspondence: Armen Trchounian, Department of Microbiology & Plants and Microbes Biotechnology, Faculty of Biology at Yerevan State University, 1 A. Manoukian Street, 0025 Yerevan, Armenia. Tel.: (37410) 570591; fax: (37410) 554641; e-mail: Trchounian@ysu.am

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Abstract

Simultaneous measurement of redox potential (Eh) and determination of H2 evolution kinetics using a pair of titanium silicate and platinum redox electrodes in fermenting cultures of Escherichia coli wild type and different mutants lacking hydrogenases 1 (Hyd-1) or 2 (Hyd-2) revealed that Hyd-1 controls the onset of H2 evolution at slightly alkaline pH (pH 7.5) and under oxidizing Eh. In addition, Hyd-2 influences the N,N'-dicyclohexylcarbodiimide-inhibited ATPase activity in fermenting cells and thus regulates the proton F0F1-ATPase at the alkaline pH but under reducing Eh.

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