EFFECT OF TEMPERATURE ON MICROBIAL GROWTH

Question 1

What is the physical factor that may critically affect microbial growth?

Answer 1

Temperature

Question 2

Define optimal growth temperature

Answer 2

the specific biochemical reactions progress at maximum speed

Question 3

What are the bacterias that grow at extreme temperatures (0°C) called?

Answer 3

Psychrophiles

Question 4

What are the bacterias that require high temperatures (75°C) called?

Answer 4

Thermophiles

Question 5

What is the term that describes the bacterias that grow between the temperatures of 20 and 45° (normal)?

Answer 5

Mesophiles

Question 6

What is the purpose of the effect of temperature on microbial growth experiment?

Answer 6

to measure the effects of various temperatures on the growth rate and pigment production of different bacteria

Question 7

What are the types of broth cultures used for the temperature experiment?

Answer 7

• Staphylococcus aureus (lvl 2)
• Serratia marcescens
• Pseudomonas fluorescens
• Bacillus stearothermophilus

Question 8

What are the types of slant culture used?

and its slant cultures on the agar

Answer 8

Sabouraud’s agar slant
- Saccharomyces cerevisiae (yeast)
- Aspergillus niger (fungi)

Question 9

What are the species that resulted white/mold growth?

Answer 9

Aspergillus niger and Pseudomonas fluorescens

Question 10

Name 2 cellular components involved in metabolism that are influenced by temperature changes?

Answer 10

Ribosomes and enzymes

Question 11

Differentiate between thermophile and psychrophiles. Give an example of each

Answer 11

Thermophiles - grow above 55° (pseudomonas fluroscens)
Psychrophiles - grow below 20° (serratia marscens)

Question 12

What is the optimum growth temperature for most human pathogens?

Answer 12

37°, because that is the human body’s temperature

Question 13

What was the optimal growth temperature for Bacillus stearothermophilus?

Answer 13

higher, therefore 55-75 degrees