Microbial Growth Lecture 2

Question 1

Autotrophs

Answer 1

Obtain carbon from CO2 and carbonates

Question 2

Heterotrophs

Answer 2

Obtain carbon and other nutrients from organic compounds

Question 3

Phototrophs

Answer 3

Obtain energy from light

Question 4

Chemotrophs

Answer 4

Obtain energy from oxidation of inorganic compounds (chemoautotrophs) or organic compounds (chemoheterotrophs)

Question 5

Cardinal temperatures

Answer 5

The minimum, optimum, and maximum temperatures for bacterial growth

Question 6

Psychrophiles

Answer 6

Cold, optimum temperature 15 degrees or below
E.g. Listeria monocytogenes
Cytoplasmic membrane has greater content of unsaturated fatty acid chains

Question 7

Mesophiles

Answer 7

Grow best at body temperature

Question 8

Thermophiles & hyperthermophiles

Answer 8

Grow best in warm conditions.

High proportion of saturated fatty acids in cytoplasmic membrane

Question 9

Halophiles

Answer 9

Require some salt for growth

Question 10

Halotolerant

Answer 10

Can withstand some reduction in aw (water availability)

Question 11

Extreme halophile

Answer 11

Can survive very salty conditions

Question 12

What is selective media?

Answer 12

Contains a compound that inhibits growth of specific microorganisms

Question 13

What is differential media?

Answer 13

An indicator is used (dye) to distinguish between organisms with different metabolic/chemical reactions

Question 14

What do Brilliant Green Agar and Eosin Methylene Blue agars select for?

Answer 14

Selects for Gram negative, inhibits positive.

Question 15

How does Rambach media differentiate bacteria?

Answer 15

Salmonella is red