BIO SCI M118L (MICROBIO LAB) QUIZ 1 Ques ons and
answers/updated
Where do you dispose contaminated items?
biohazard containers
Where do you dispose broken glass?
disposable glass containers
Where do you place non-disposable items?
dirty dish carts
What sources do bacteria require to survive?
carbon and nitrogen (possibly amino acids, vitamins, and other growth factors)
defined media
all components have been characterized and are known
complex media
contains one or more ingredients of unknown composi"on
peptones
unknown components; nutrient rich extracts from milk, yeast, beef, etc.
selec"ve media
inhibits growth of a group of organisms
example of selec"ve media
MacConkey agar: contains bile salts that destroy the cell walls of gram posi"ve bacteria,
inhibi"ng their growth -> only gram nega"ve bacteria can grow
enriched media
contains ingredients that promote the growth of fas"dious organisms
fas"dious organisms
organisms that only grow when there are certain nutrients available
example of enriched media
, chocolate agar: contains red blood cells lysed with heat -> permits growth of organisms that
require growth factors found inside red blood cells
differen"al media
allows one to dis"nguish between different types of bacteria growing on a single plate
- colored dyes taken up by specific organisms
- pH indicators that alter the color of media surrounding a colony depending on the secre"on
example of differen"al media
MacConkey agar: contains pH indicator neutral red
- organisms that ferment lactose (sugar in the media) produce an acid end product -> lowers pH
-> turns red
- organisms that do not ferment lactose remain colorless
purpose of streaking
to dilute original sample to obtain single colonies
purpose of ABA DABA process
ini"al iden"fica"on of the organism; either gives you the family or genus of the bacterium
wet mount test
determines whether organism is mo"le
fluorescent pigment test
determines whether organism secretes a water soluble pigment
endospore test
determines whether organism can form spores
EMB media
- Differen"al: contains eosin and methylene blue (dyes) that are taken up by lactose fermen"ng
organisms
- Selec"ve: prevent growth of gram posi"ve organisms by interfering with the forma"on of their
cell walls
S1 (Gould's formula"on) media
Selec"ve:
- Contains SLS, a detergent that alters the cell membrane of Gram posi"ve bacteria and prevents
answers/updated
Where do you dispose contaminated items?
biohazard containers
Where do you dispose broken glass?
disposable glass containers
Where do you place non-disposable items?
dirty dish carts
What sources do bacteria require to survive?
carbon and nitrogen (possibly amino acids, vitamins, and other growth factors)
defined media
all components have been characterized and are known
complex media
contains one or more ingredients of unknown composi"on
peptones
unknown components; nutrient rich extracts from milk, yeast, beef, etc.
selec"ve media
inhibits growth of a group of organisms
example of selec"ve media
MacConkey agar: contains bile salts that destroy the cell walls of gram posi"ve bacteria,
inhibi"ng their growth -> only gram nega"ve bacteria can grow
enriched media
contains ingredients that promote the growth of fas"dious organisms
fas"dious organisms
organisms that only grow when there are certain nutrients available
example of enriched media
, chocolate agar: contains red blood cells lysed with heat -> permits growth of organisms that
require growth factors found inside red blood cells
differen"al media
allows one to dis"nguish between different types of bacteria growing on a single plate
- colored dyes taken up by specific organisms
- pH indicators that alter the color of media surrounding a colony depending on the secre"on
example of differen"al media
MacConkey agar: contains pH indicator neutral red
- organisms that ferment lactose (sugar in the media) produce an acid end product -> lowers pH
-> turns red
- organisms that do not ferment lactose remain colorless
purpose of streaking
to dilute original sample to obtain single colonies
purpose of ABA DABA process
ini"al iden"fica"on of the organism; either gives you the family or genus of the bacterium
wet mount test
determines whether organism is mo"le
fluorescent pigment test
determines whether organism secretes a water soluble pigment
endospore test
determines whether organism can form spores
EMB media
- Differen"al: contains eosin and methylene blue (dyes) that are taken up by lactose fermen"ng
organisms
- Selec"ve: prevent growth of gram posi"ve organisms by interfering with the forma"on of their
cell walls
S1 (Gould's formula"on) media
Selec"ve:
- Contains SLS, a detergent that alters the cell membrane of Gram posi"ve bacteria and prevents
