6. Two continuous bioreactors containing the same organisms, fed with the same feed at the same dilution rate were compared. Reactor 1 started with an initial concentration of glucose of 10 g.l-1, while reactor 2 contained 0.1 g.l-1 of glucose at the start of the process then at steady state
Options
A. the concentration of glucose in reactor 1 would be greater than that in reactor 2
B. the concentration of glucose in reactor 1 would be equal to reactor 2
C. the concentration of glucose in reactor 1 would always be zero.
D. the concentration of glucose in reactor 1 would be less than that in reactor 2
Correct Answer: the concentration of glucose in reactor 1 would be equal to reactor 2
7. In a glucose-yeast extract medium, Lactococcus lactis has a maximum specific growth rate (um) of 1.23 h-1. What would be the specific growth rate of this organism at steady state in a 4 litre reactor being fed at 2 litres per hour?
Correct Answer: ferment in the presence of high concentrations of sugar and dissolved oxygen
10. Production of organic acids in batch culture is generally growth associated phase followed by non-growth associated production. The probable reason for this is that
Options
A. organic acids uncouple catabolism from anabolism
B. biomass yields increase as the fermentation proceeds
C. organic acids are secondary metabolites
D. high concentrations of organic acid promote the growth of the microbial population