Which term refers to microorganisms that survive best in a microenvironment with a pH of 2-2.8?
A. acidophiles
B. alkaliphiles
C. pH tolerant
D. extreme alkaliphiles
The correct answer and explanation is :
The correct answer is:
A. Acidophiles
Explanation:
Acidophiles are microorganisms that thrive in acidic environments, particularly those with a pH range of around 2 to 2.8. These microorganisms have evolved unique adaptations that allow them to maintain their cellular functions and structural integrity in such harsh conditions. Acidophilic organisms are commonly found in environments like acid mine drainage, sulfuric hot springs, and acidic soils, where the pH is typically low.
Acidophiles can be further classified based on their tolerance to acidity:
- Moderate acidophiles: These organisms thrive in environments with a pH between 4.0 and 5.5.
- Extreme acidophiles: These microorganisms can survive and grow in highly acidic environments, often with a pH as low as 2.0 or even lower. They have specialized mechanisms to cope with the extreme acidity, such as the ability to pump out protons (H⁺ ions) to maintain a neutral internal pH.
The ability of acidophiles to survive in such low pH environments can be attributed to several biological mechanisms:
- Cell membrane adaptation: Acidophiles have specialized cell membranes that are more resistant to the damaging effects of acidic conditions.
- Proton pumps: These organisms often possess proton pumps that actively expel excess protons from their cells, maintaining a neutral internal pH.
- Enzyme activity: Enzymes in acidophiles are adapted to function optimally in acidic conditions, enabling these microorganisms to carry out metabolic processes efficiently.
Acidophiles are significant in various industrial applications, such as bioleaching, where they help extract metals from ores in acidic environments, or in the production of acidic foods and beverages like yogurt and pickles.
Other terms mentioned in the question:
- B. Alkaliphiles: These organisms thrive in basic (alkaline) environments, typically with a pH above 8.0.
- C. pH tolerant: This is a general term for organisms that can tolerate a wide range of pH conditions but don’t necessarily prefer extreme pH environments.
- D. Extreme alkaliphiles: These organisms thrive in environments with a pH above 9.0 and can survive in highly alkaline conditions.
Here is an illustration of an acidic environment where microorganisms called acidophiles thrive in a pH range of 2-2.8. It visually shows the acidic water or soil, and the acidophiles living in such conditions.