Question

Zymomonas mobilis was used to convert glucose to ethanol in a batch fermenter. 5g
of bacteria was inoculated into 50 L of the fermentation medium. If the specific growth
rate of the culture is approximately 0.3 h-1, determine the batch time required to produce
10 g of biomass.
Zymomonas mobilis was used to convert glucose to ethanol in a 60 L ideal continuous
stirred tank reactor (CSTR). At steady state the specific growth rate of the culture is
0.26 h-1 and the substrate concentration inside the reactor is 1.5 g/L. Determine the sterile
inlet feed flow rate in this Chemostat.

Answer 1

1. If 10 g biomass is produced by the reaction, the final amount of biomass present =(10+5)=15 g; maxmum specific growth rate of the culture= 0.3 h-1; therefore, final concentration, and initial concentration,

Batch time,

2. At steady state, specific growth rate of the culture, D=0.26 h-1; Volume of the tank reactor, V=60 L

Sterile inlet flow rate, L/h