Microbial Growth

Question 1

What is Microbial Growth

Answer 1

An increase in the number of organisms

Question 2

Different bacteria have different growth requirements. Microbiologists group these requirements into two groups. What are these groups?

Answer 2

Chemical Requirements and
Physical Requirements

Question 3

What are the 3 Categories of Physical Requirements for Growth?

Answer 3

1. Temperature
2. pH
3. Osmotic Pressure

Question 4

pH range for growth (depending on the bacteria

Answer 4

2-12

Question 5

Osmotic pressure range for growth (NaCl)

Answer 5

1% to 30% NaCl

Question 6

Temperature range for growth (descriptive)

Answer 6

Near Freezing to Past Boiling

Question 7

What are the 3 temperatures that cover the range at which a particular bacteria can grow?

Answer 7

Minimum Growth Temperature
Optimum Growth Temperature
Maximum Growth Temperature
(*not the maximum growth rate)

Question 8

Does Bacteria die outside of its growth range?

Answer 8

Not always

Question 9

Bacteria are classified into 5 categories based on their temperature tolerances. What are these 5 categories?

Answer 9

-Hyperthermophiles
-Thermophiles
-Mesophiles
-Psychrotrophs
-Psychrophiles

Question 10

Hyperthermophiles

Answer 10

Some members of Archaea, “Extreme Thermophiles”

Question 11

Psychrophiles

Answer 11

Cold Loving Microbes

Question 12

Mesophiles

Answer 12

Moderate Temperature *Most Common

Question 13

Thermophiles

Answer 13

Heat Loving Microbes

Question 14

Psychrotrophs

Answer 14

Capable of growing between 0 and 30 degrees Celsius (Refrigerator Temp)