Question

What is used to provide a constant flow of growth medium to keep microorganisms in a logarithmic phase of growth?

• A. Chemostat
• B. Autoclave
• C. Laminar flow
• D. Fermentor

Hint:

Think of a continuous culture system, not a batch culture.

Answer 1

The Correct Option is A

Step 1: In a normal batch culture, microorganisms go through lag, log, stationary and death phases because nutrients run out and waste builds up.

Step 2: A chemostat is a continuous culture device that constantly feeds in fresh medium at a fixed rate while removing an equal volume of culture, which keeps nutrient concentration and cell density steady.

Step 3: Because nutrients never get depleted, the population is held in the exponential (log) phase of growth for a long time.

Step 4: An autoclave sterilizes equipment and media, laminar flow provides a sterile air chamber for handling cultures, and a fermentor is a general vessel for large scale culture that need not be run continuously. So the specific answer is chemostat.