Microbial Growth and its control

Question 1

Environmental factors that influence bacterial growth

Answer 1

Temperature, pH, Water and Osmotic pressure, Absence or presence of Oxygen

Question 2

Optimum growth temperature for bacteria that are involved with infectious diseases

Answer 2

35-40 degrees Celsius

Question 3

Most bacteria are neutrophiles, meaning ——. So most bacteria live in environments with a pH range of ——–. The internal pH of a bacterial cell is ———.

Answer 3

Their pH optimum is near neutral.
pH range of 5-8.
The internal pH is pH 7.

Question 4

Examples of Moist Heat methods to control microbial growth

Answer 4

Boiling, Pasteurization, Autoclaving

Question 5

Examples of Dry Heat methods to control microbial growth

Answer 5

Incineration
Hot Air Sterilization

Question 6

Refrigeration has a ‘bacteriostatic’ effect. What does this mean?

Answer 6

Stops bacteria from growing, slows the rate for energy production

Question 7

What chemical agent(s) is most suitable for decontamination of blood spills?

Answer 7

Chlorine

Question 8

What process cannot achieve sterilization?

Answer 8

Pasteurization