Question

The rate at which substrate is consumed by microorganisms is directly related to

• A. Only substrate concentration
• B. Only product concentration
• C. Cell concentration
• D. Temperature only

Hint:

According to microbial growth kinetics, \[ \boxed{ \text{Substrate utilization rate} \propto \text{Biomass (cell concentration).} } \] Increasing the number of active cells generally increases substrate consumption.

Answer 1

The Correct Option is C

Step 1: Recall substrate utilization kinetics. The rate of substrate consumption depends primarily on the amount of active microbial biomass present. More cells consume substrate at a faster rate.

Step 2: Identify the correct factor. Therefore, substrate consumption is directly proportional to \[ \boxed{\text{Cell concentration}.} \] Hence, \[ \boxed{(C)} \] is the correct answer.