Control of Bacteria

Question 1

Sterile

Answer 1

Has no living microorganisms

Aseptic

Question 2

Disinfected

Answer 2

All living vegetative cells are gone but spores and viruses may be present
[Medical definition: all pathogenic organisms are killed]

Question 3

Antiseptic

Answer 3

A chemical disinfectant that is safe to use on human tissue

Question 4

Degerming

Answer 4

The mechanical removal of microbes from a surface. Good at removing transient bacteria

Question 5

Sanitizing

Answer 5

Microbe levels are reduced to safe public health levels

Question 6

Thermal Death Point

Answer 6

TDP. Min temp that will kill all cells of a given species in a liquid medium in 10 minutes

Question 7

Thermal Death Time

Answer 7

TDT. Min time to kill all cells of a given species in a liquid medium at a given temp

Question 8

Decimal Reduction Time

Answer 8

DRT. D-value. Time (in min) in which 90% of a type of cell in a liquid medium will be killed at a given temperature.

Question 9

Physical Methods of Control

Answer 9

• Heat (most common)
• Radiation
• Filtration
• Cold
• Drying
• Lyophilization (freeze-drying)
• Treat with High Salt or High Sugar