BACE Bioprocessing and Fermentation 3

Question 1

What is the purpose of a 'seed train' in biopharmaceutical manufacturing?

Accepted Answer

To progressively expand cell cultures from a small vial to volumes large enough to inoculate the production bioreactor

Answer

A seed train is a series of sequential culture steps that expand cell numbers from a frozen working cell bank vial up to production bioreactor inoculation volume.

Question 2

Which method is commonly used to separate cells from fermentation broth during harvest?

Accepted Answer

Centrifugation or depth filtration

Answer

Centrifugation and depth filtration are primary harvest methods that separate cells (or cell debris) from the broth containing the desired product.

Question 3

What is 'fed-batch fermentation'?

Accepted Answer

A process where nutrients are periodically or continuously added to the bioreactor during the run without removing broth

Answer

Fed-batch fermentation adds nutrients incrementally during the process to prevent substrate inhibition and extend the productive growth phase.

Question 4

What is the significance of the 'specific growth rate' (μ) in fermentation?

Accepted Answer

It describes how fast cells are growing relative to the existing cell mass at a given moment

Answer

Specific growth rate (μ, units: h⁻¹) expresses the rate of increase in biomass per unit of existing biomass, defining the exponential growth kinetics.

Question 5

Why is controlling temperature important during cell culture in a bioreactor?

Accepted Answer

Because temperature affects enzyme activity, cell growth rate, product formation, and product quality

Answer

Temperature directly influences metabolic enzyme kinetics, protein folding, glycosylation patterns, and cell viability, all affecting yield and product quality.

BACE - Biotechnician Assistant Credentialing Exam Practice Test

BACE - Biotechnician Assistant Credentialing Exam Practice Test

BACE Bioprocessing and Fermentation 3