Controlling microbial growth in vitro

Question 1

Factors that affect Microbial Growth

Answer 1

1. Availability of nutrients
2. Moisture
3. Temperature
4. pH
5. Osmotic pressure
6. Salinity
7. barometric pressure
8. gaseous atmosphere

Question 2

removal of moisture or a dry environment

Answer 2

Dessication

Question 3

is the temperature required by organisms to grow best

Answer 3

Optimum temperature

Question 4

organisms that grow at high temperatures (they love heat)

examples: Cynobacteria

Answer 4

thermophiles

Question 5

organisms that favor growth above 100c

examples: pyrolobus fumarii

Answer 5

Extreme thermophiles or Hyperthermophiles

Question 6

organisms that grow at a moderate temperature (37c)

Answer 6

Mesophiles

Question 7

cold loving organisms; grows best at-13c

examples: yersinia monocytogenes

Answer 7

psychrophiles

Question 8

refrigerator temperature; optimum growth temperature of 4c

examples: bread molds

Answer 8

Psychotrops

Question 9

prefer warm temperatures but can tolerate cold temperature

Answer 9

Psychoduric organisms

Question 10

prefer a pH of 2-5

Answer 10

Acidophiles

examples: Lactobacillus acidophilus

Question 11

prefer pH >8.5

Answer 11

Alkaliphiles

Example: Vibrio cholerae

Question 12

pressure that is exerted on a cell membrane by solutions both inside and outside the cell

Answer 12

Osmotic pressure

Question 13

Movement of solvent through a permeable membrane from a solution having a lower concentration to a higher concentration

Answer 13

osmosis

Question 14

A solution with INCREASE concentration of solutes

Answer 14

hypertonic solution

Question 15

bacterial cell membrane and cytoplasm SHRINK away from the bacterial cell wall

Answer 15

plasmolysis

happens when placed in a HYPERTONIC SOLUTION

Question 16

A solution with DECREASE concentration of solutes

Answer 16

hypotonic solution

Question 17

bacterial cell RUPTURES and the cytosol escapes

Answer 17

Plasmoptysis

happens when placed in a HYPOTONIC solution

Question 18

Concentration of the fluid where the cells are suspended is equal to the concentration of the fluids inside the cells

Answer 18

isotonic solution

Question 19

organisms that grown BEST at a salty environment ; “halo” salty

Answer 19

halophilic organisms

example: Vibrio spp

Question 20

organisms that DO NOT prefer salty environment but CAN SURVIVE

Answer 20

haloduric organisms

example; Staphyloccocus Aureus

Question 21

microorganisms that survive deep in the ocean or in oil wells where atmospheric pressure is very high

Answer 21

Piezophiles

Question 22

Organisms which REQUIRE OXYGEN to live

Answer 22

Obligate aerobes

Question 23

bacteria that grow on the ABSENCE of atmospheric or free oxygen and obtain oxygen from oxygen-containing compound

Answer 23

Obligate anaerobes

Examples : Mycobacterium and micrococus

Question 24

an anaerobes, but can grow in the PRESENCE of atmospheric oxygen

Answer 24

Facultative aerobes

Question 25

Require increase Carbon dioxide

Answer 25

Capnophiles

Question 26

DOES NOT GROW WELL, but survives in the presence of atmospheric oxygen q

Answer 26

Aerotolerant

Question 27

Requires REDUCED oxygen

Answer 27

Microaerophiles

Question 28

Artificial or synthetic media used in the laboratory to grow microorganisma

Answer 28

Culture media

Question 29

destruction of or elimination of all microbes, including cells, spores, and viruses

Answer 29

Sterilization

Question 30

elimination of most or all pathogens except bacterial spores, form nonliving objects

Answer 30

Disinfection

Question 31

Chemical used to disinfect inanimate objects are called

Answer 31

Disinfectant

Question 32

Chemicals used to disinfect skin and other living tissues are calles

Answer 32

Antiseptic

Question 33

method used to disinfect liquids, milk, wine, and other beverages

Answer 33

pasteurization

Question 34

Reduction of bacterial population to levels considered safe by Public Health Standard

Answer 34

Sanitization

Question 35

Drugs or chemical that KILL bacteria

Answer 35

bactericidal Agents

Question 36

Used to kill bacterial Endospore

Answer 36

Sporicidal agents

Question 37

drugs or chemical that can inhibit growth and multiplication of bacteria

Answer 37

bacteriostatic agents

Question 38

The process of dehydration (drying) followed by freezing to preserve the bacteria for future use and study

Answer 38

lyophilization

Question 39

Refers to the presence of pathogen in blood or tissue

Answer 39

Sepsis

Question 40

absence of pathogen

Answer 40

Asepsis

Question 41

is the prevention of infection

Answer 41

Antisepsis

Question 42

Mechanical removal of microbes rather than killing from a limited area, for example the skin around an injection site

Answer 42

Degerming/Degermation

Question 43

the time necessary to kill microorganisms is DIRECTLY PROPORTIONAL to the number of microorganisms present

Answer 43

TRUE

Question 44

hard water may REDUCE the rate of killing microorganisms

Answer 44

TRUE

Question 45

70% alcohol is more effective that 95% alcohol due to its water content

Answer 45

TRUE