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Kinetic model of hydrogen generation by Rhodobacter sphaeroides in the presence of NH 4 + ions
Author(s) -
Waligórska M.,
Seifert K.,
Górecki K.,
Moritz M.,
Łaniecki M.
Publication year - 2009
Publication title -
journal of applied microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.889
H-Index - 156
eISSN - 1365-2672
pISSN - 1364-5072
DOI - 10.1111/j.1365-2672.2009.04314.x
Subject(s) - rhodobacter sphaeroides , hydrogen production , hydrogen , ammonium , chemistry , ion , inorganic chemistry , biomass (ecology) , nitrogen , ammonium sulfate , photosynthesis , organic chemistry , biochemistry , ecology , biology
Aims: To examine the effects of ammonium ion concentration and illumination intensity on the effectivness of the hydrogen generation process of Rhodobacter sphaeroides . Methods and Results: In all experiments the amount of evolved hydrogen, biomass growth, concentration of ammonium ions, pH and chemical oxygen demand were measured. A nonstructural kinetic model was applied in description of biomass growth, the amount of evolved hydrogen and consumption of organic compounds and ammonium ions. An increase of ammonium ions concentration resulted in a decrease of maximal specific hydrogen potential production. At higher ammonium ion concentrations, no hydrogen evolution was observed. The efficiency of malic acid conversion into hydrogen and the PHB content in the biomass were the highest with lower concentrations of nitrogen compounds. Conclusion: The presence of ammonium ions inhibits hydrogen photogeneration. A good agreement between the experimental data and model simulations were obtained. In all cases, hydrogen evolution started after an exhaustion of ammonium ions and the increase was proportional to the C/N ratio in the medium. The accumulation of PHB competes with the hydrogen evolution process while the conversion of acids into biomass was limited at higher levels of hydrogen generation. Significance and Impact of the Study: Confirmation of the suitability of the selected model for kinetic studies of hydrogen photoevolution.