Reaction engineering studies of autohydrogenotrophic nitrate respiration of Cupriavidus necator
Armin Tiemeyer, doctoral thesis Technische Universität München, 2007
So far the cultivation of the bacterium Cupriavidus necator with hydrogen, carbon dioxide and oxygen was described for the production of a biodegradable polymer (polyhydroxybutyrate) from carbon dioxide. In contrast to oxygen respiration the use of nitrate as terminal electron acceptor would improve process safety and would enable an industrial scale process at ambient pressure. Consequently, the goal of this work was the identification of the kinetics of the autohydrogenotrophic growth of Cupriavidus necator with nitrate as terminal electron acceptor. Kinetic models with 9 parameters were found to be sufficient to describe batch and fedbatch growth as well as substrate consumption rates in stirred-tank bioreactors. The identified maximum specific growth rate of Cupriavidus necator (0.749 1/d) appeared to be unexpected low with nitrate as terminal electron acceptor.