Improvement of the initial stage of the autotrophic growth of hydrogen bacteria, strain 9-5 in sparged cultures was performed by employing air instead of pure oxygen as oxygen source. Elongation of exponential growth phase was also achieved with the aid of the determination of dissolved concentrations of hydrogen and oxygen. Under the gas composition, H2:O2:CO2=67:23:10, dissolved concentrations of both hydrogen and oxygen were reduced to zero at the end of the exponential growth phase in sparged cultures. In addition, theoretical considerations for obtaining the optimal ratio of hydrogen and oxygen for the maximum critical cell concentration were performed.
Japan Society for Bioscience, Biotechnology, and Agrochemistry