07 Bioprocessing and Bioreactors Online Quiz Questions

In a stirred-tank bioreactor, what is the main purpose of baffles?

In a batch process, the main nutrients are supplied at the start of cultivation, and the culture proceeds until harvest.

What is the term for the sequence of progressively larger cultures used to expand cells before they are inoculated into a production bioreactor?

An aerobic culture needs gas supplied as bubbles. Which stirred-tank component performs this function?

Which of the following are common process variables monitored during bioreactor operation? Select all that apply.

When scaling up a bioprocess, engineers generally cannot keep every scale-up criterion constant at the same time.

Use $\text{OTR} = k_La(C^* - C_L)$. If $k_La = 4\,\text{h}^{-1}$, $C^* = 8\,\text{mg/L}$, and $C_L = 3\,\text{mg/L}$, what is the oxygen transfer rate?

An aerobic culture has low dissolved oxygen. Which response is described as a possible control action, subject to process limits?

Which of the following are examples of criteria engineers may use to guide bioprocess scale-up? Select all that apply.

A process team considers increasing agitation to address oxygen limitation. Explain one potential benefit and two potential costs or risks, and state why the choice should depend on the particular culture.

A production culture receives additional nutrients during cultivation, and operators adjust the feed rate to help manage growth and product formation. Which operating mode is being used?

A production culture receives additional nutrients while cultivation is underway. Which operating mode is being used?

In a stirred-tank bioreactor, which component introduces air or other gases into the culture as bubbles?

During bioprocess scale-up, can engineers generally keep all selected scale-up criteria—such as constant kLa, constant P/V, and similar mixing time—constant at the same time?

What term describes a sequence of progressively larger cultures used to expand cells before inoculation into the production bioreactor?

A stirred-tank culture swirls strongly, and mixing needs improvement. What is the main role of adding baffles?

A bioreactor’s pH needs correction during cultivation. Which control action is consistent with the process described in the material?

A team has completed cultivation in its production bioreactor and harvested the culture. What is the name of the processing stage that follows upstream production?