6. Mixing in an anaerobic sludge blanket reactor is due to

A. rapid change in water temperatures throughout the reactor
B. release of gases by the microbial populations
C. swimming of microbes
D. none of the above

7. In batch culture, protogon is produced from peptone during the stationary phase with a yield of 0.4 protogon mg per g of peptone. If it is to be produced in a chemostat at a dilution rate of 0.5 h^-1 from a medium containing 10 g.l^-1 of peptone, then the rate of protogon synthesis would be

A. 0 g.l^-1h^-1
B. 0.5 g.l^-1h^-1
C. 1 g.l^-1h^-1
D. 2 g.l^-1h^-1

8. Formation of end product by Lactococcus lactis will become non-growth associated as lactic acid accumulates because

A. cells will redirect ATP to anabolism
B. cells will redirect NAD⁺to anabolism
C. cells will redirect ATP to facilitate the diffusion of lactic acid and H⁺out of the cells
D. cells will redirect ATP to the active transport of lactic acid and H⁺out of the cells

9. Which of the following would not be subjected to the “glucose effect”?

A. Aspergillus fumigatus
B. Saccharomyces cerevisiae
C. Escherichia coli
D. Aspergillus niger

10. 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