Question

The supply of substrate for production and maintenance is different.

(a) True

(b) False

I have been asked this question in final exam.

I'm obligated to ask this question of Kinetics of Cell Substrate Uptake in Cell Culture in division Homogenous Reactions of Bioprocess Engineering

Answer 1

The correct answer is:

(a) True

Explanation:

In bioprocess engineering, particularly in the context of cell culture, the substrate supply is indeed different for production and maintenance.

• Substrate for production refers to the nutrients (like glucose, amino acids, etc.) used by cells to produce biomass and other metabolites, such as products of interest (e.g., enzymes, proteins, or biofuels). The primary goal is to support the growth and proliferation of the cells for efficient production of the target product.

• Substrate for maintenance refers to the nutrients that the cells need to maintain their viability and function, even in the absence of active growth. This includes energy needed for maintaining basic cellular functions like protein synthesis, ion transport, and repair mechanisms. Maintenance metabolism typically consumes substrate more slowly compared to growth metabolism.

The total substrate consumption in a bioreactor is typically the sum of the substrate used for both growth (production) and maintenance. However, these are distinct processes and are governed by different kinetic rates, and often, the rate of substrate uptake for maintenance is considered when cells are not actively dividing.

Thus, the statement is true.