200 Best MCQs on Fermentation Reactors- biochemical engineering
Q9). Immobilized cell reactors for wastewater treatment have the advantage of having/being
a).higher cell concentration
b).more stable and prevent washout
c).higher dilution rate before the cells washout
d).all of the above
Correct Answer:
all of the above
Explaination:
Q10). Which of the statement is true for continuous reactor at steady state?
a).The rates of biomass, substrate and product concentrations are zero
b).Biomass, substrate and product concentrations are zero
c).Biomass, substrate and product concentrations do not change with time
d).Biomass, substrate and product concentrations change with time
Correct Answer:
Biomass, substrate and product concentrations do not change with time
Explaination:
Q11). A continuous bioreactor in which only the flow rate is used to control the rate of cell or product productivity is called
a).turbidostat
b).chemostat
c).level stat
d).pH
Correct Answer:
chemostat
Explaination:
Q12). For organisms growing in a chemostat, the specific growth rate
a).cannot be determined
b).can be determined from the dilution rate
c).equals to the maximum specific growth rate of the culture
d).none of the above
Correct Answer:
can be determined from the dilution rate
Explaination:
Q13). Saccharomyces cerevisiaeis being grown in a chemostat converts glucose to biomass, ethanol, glycerol and carbon dioxide. At steady state, the concentration of glucose, biomass, ethanol and glycerol will
a).decrease with time
b).increase with time
c).be constant
d).change randomly with time
Correct Answer:
be constant
Explaination:
Q14). In aerobic yeast fermentation for production of citric acid from alkanes using a fed-batch culture, why alkanes are slowly fed to the yeast?
a).Citric acid is toxic to the cells
b).Alkanes cause foaming
c).Fast addition of alkanes will inhibit the cells and reduce oxygen transfer rates
d).Fast addition of alkanes will cause the cells to grow too quickly
Correct Answer:
Fast addition of alkanes will inhibit the cells and reduce oxygen transfer rates
Explaination:
Q15). A continuous reactor has a dilution rate of 0.5 h^-1. Its residence time would be
a).ln(2)/0.5
b).ln(2) x 0.5
c).0.5 h
d).2 h
Correct Answer:
2 h
Explaination:
Q16). Which of the following is used to calculate mass of substrate in the reactor?
a).Flow rate x substrate concentration in the reactor
b).Volume of reactor x substrate concentration in reactor
c).Flow rate x mass of reactor
d).Volume of reactor x Flow rate
Correct Answer:
Volume of reactor x substrate concentration in reactor
Explaination: