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Ch. 6 - Microbial Growth
Tortora - Microbiology: An Introduction 14th Edition
Tortora14th EditionMicrobiology: An IntroductionISBN: 9780138200398Not the one you use?Change textbook
Chapter 6, Problem 9

Which of the following is true about the optimum growth temperature of most mesophiles?
a) They can grow well at 37^0C.
b) They are more likely to grow at refrigerator temperatures.
c) They can strive well in extremely high temperatures.
d) All of the above.

Verified step by step guidance
1
Step 1: Understand the definition of mesophiles. Mesophiles are microorganisms that grow best at moderate temperatures, typically between 20°C and 45°C.
Step 2: Analyze option (a): 'They can grow well at 37^0C.' Since 37°C is within the optimal temperature range for mesophiles, this statement is true.
Step 3: Analyze option (b): 'They are more likely to grow at refrigerator temperatures.' Refrigerator temperatures are usually around 4°C, which is below the optimal range for mesophiles, so this statement is false.
Step 4: Analyze option (c): 'They can strive well in extremely high temperatures.' Extremely high temperatures refer to thermophilic conditions (above 45°C), which are not suitable for mesophiles, so this statement is false.
Step 5: Conclude that only option (a) is true based on the temperature preferences of mesophiles.

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Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

Mesophiles and Their Growth Temperature

Mesophiles are microorganisms that grow best at moderate temperatures, typically between 20°C and 45°C. Most mesophiles thrive around human body temperature (37°C), making this range optimal for their growth and metabolic activities.
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Temperature Ranges for Microbial Growth

Microorganisms are classified based on their preferred temperature ranges: psychrophiles grow best in cold environments (0-15°C), mesophiles in moderate temperatures (20-45°C), and thermophiles in high temperatures (above 45°C). This classification helps predict where microbes can survive and multiply.
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Impact of Temperature on Microbial Metabolism

Temperature affects enzyme activity and membrane fluidity in microbes, influencing their growth rate. At optimum temperatures, enzymes function efficiently, supporting rapid growth, while temperatures too low or too high can inhibit metabolism or cause cell damage.
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