Electronic Thesis and Dissertation Repository


Master of Engineering Science


Chemical and Biochemical Engineering


Lars Rehmann


Two bioprocesses were separately investigated based on their common interest of using gaseous substrates that have low solubility. The first process involved the development of a mixed culture using two organisms capable of utilizing glycerol and carbon monoxide separately to increase biobutanol production, while the second process involved an investigation of different production media used in aerobic xanthan production of Xanthomonas campestris with pressurization effects. It was determined that Clostridium pasteurianum should be used with an organism like Clostridium carboxidivorans or Eubacterium limosum in order for butyrate uptake at 3 g/L to occur with a minimum 0.1 g/L butyrate production. Likewise, a good-performing medium for xanthan production was chosen and increasing pressure saw increases to oxygen mass transfer coefficients for better yields up to 13 g/L biomass and 250 mPa·s of viscosity. Future work should be applied in connecting the results of the second process to that of the first.