Bioprocess Engineering 2nd Edition by Fikret Kargi,Michael Shuler

Exercise 8

A batch fermenter receives 1 l of medium with 5 g/l of glucose, which is the growth-rate-
limiting nutrient for a mixed population of two bacteria (a strain of E. coli and Azotobacter
vinelandii). A. vinelandii is five times larger than E. coli. The replication rates for the two or-
ganisms are: The yield coefficients are: The inoculum for the fermenter is 0.03 g dw/l of E. coli and 0.15 g dw/l of
A. vinelandii cells/ml).
What will be the ratio of A. vinelandii to E. coli at the time when all of the glucose is
consumed?
Example 16.1.
Competition of two species for the same growth-rate-limiting substrate is common. Deter- mine when the two organisms may stably coexist if both A and B follow Monod kinetics.