Question

Bacteria which grow in 0.5 to 3.0% salt are called:

• A. Psychrophiles
• B. Halophilic
• C. Mesophilic
• D. Thermophilic

Hint:

The word "Halo" comes from the Greek word for salt. Most marine bacteria are slight halophiles as the average salinity of seawater is about 3.5%.

Answer 1

The Correct Option is B

Concept: Microorganisms are classified based on their environmental requirements for growth.

• Temperature-based: Psychrophiles (cold), Mesophiles (medium), Thermophiles (hot).

• Salt-based: Halophiles (salt-loving).

Step 1: Defining Halophiles.
Halophiles are "salt-loving" organisms that require salt for growth. They are adapted to high osmotic pressure environments.

Step 2: Classification by concentration.
Slight halophiles grow best in 0.5% to 3% salt. Moderate halophiles prefer 3% to 15% salt. Extreme halophiles require 15% to 30% salt.

Step 3: Matching with the question.
The range 0.5% to 3.0% corresponds to the halophilic category. Final Answer: (B)