A bacterial culture having a specific oxygen uptake rate of 5 mmol O2 (g DCW)⁻¹ h⁻¹ is being grown aerobically in a fed-batch reactor. The maximum value of the volumetric oxygen transfer coefficient is 0.18 s⁻¹ for the stirred tank bioreactor and the critical dissolved oxygen concentration is 20% of the saturation concentration (8 mg L⁻¹). The maximum density to which the cells can be grown in the fed-batch process, without the growth being limited by oxygen transfer, is approximately

#Question id: 14316

#Section 5: Bioprocess Engineering and Process Biotechnology

Cellulomonas bacteria used as single-cell protein for human or animal food are produced from glucose under anaerobic conditions. All carbon in the substrate is converted into biomass; ammonia is used as nitrogen source. The molecular formula for the biomass is CH_I.560_0.54N_0.16; the cells also contain 5% ash. How does the yield of biomass from substrate in mass and molar terms compare with the maximum possible biomass yield?

#Question id: 14317

#Section 5: Bioprocess Engineering and Process Biotechnology

system for manufacture of single-cell protein is Methylophilus methylotrophus. This organism is produced aerobically from methanol with ammonia as nitrogen source. The molecular formula for the biomass is CH _1.680_0.36N_0.22; these cells contain 6% ash. What is the maximum possible biomass yield from methanol?

#Question id: 14318

#Section 5: Bioprocess Engineering and Process Biotechnology

system for manufacture of single-cell protein is Methylophilus methylotrophus. This organism is produced aerobically from methanol with ammonia as nitrogen source. The molecular formula for the biomass is CH _1.680_0.36N_0.22; these cells contain 6% ash. If the actual yield of biomass from methanol is 42% the thermodynamic maximum, what is the oxygen demand?

#Question id: 14319

#Section 5: Bioprocess Engineering and Process Biotechnology

Both Saccharomyces cerevisiae yeast and Zymomonas mobilis bacteria produce ethanol from glucose under anaerobic conditions without external electron acceptors. The biomass yield from glucose is 0.11 g g^-1 for yeast and 0.05 g g^-I for Z. mobilis. In both cases the nitrogen source is NH₃. Both cell compositions are represented by the formula CH_1.80_0.5N_0.2. What is the yield of ethanol from glucose by Saccharomyces cerevisiae yeast?

#Question id: 14321

#Section 5: Bioprocess Engineering and Process Biotechnology

Both Saccharomyces cerevisiae yeast and Zymomonas mobilis bacteria produce ethanol from glucose under anaerobic conditions without external electron acceptors. The biomass yield from glucose is 0.11 g g-1 for yeast and 0.05 g g-I for Z. mobilis. In both cases the nitrogen source is NH 3. Both cell compositions are represented by the formula CH 1.800.5N0.2. Compare actual yield with theoretical maximum for Zymomonas mobilis bacteria ?