Prokaryotes and Bacteria 2 Flashcards
What was measured regarding the bacteria grown?
abundance and diversity
What is colony morphology?
describing overall colonies that bacteria are a part of
What happens if a replicate swab all have high abundance and low diversity?
the sample will be same if the same area is swabbed again
What happens if replicate swab have different colony results, and what five reasons may cause it?
Unreliable source
could be due to incorrect swabbing
different incubation periods
where it was swapped
temperature it was incubated
sources of contamination
How many colony shapes exist?
round
irregular
filamentous
rhizoid
curled
What are the colony edge/margins?
entire
filamentous
irregular undulate
irregular lobate
What are colony elevation?
raised
flat
convex
umbonate
growth into medium
Gram staining process (10)
- swab
- smear
- flame
- add 1-2 drops crystal violet- 20 seconds
- rinse with water- 2 seconds
- add 1-2 drops gram’s iodine- 1 minute.
- riunse with decolorizer (ethyl alcohol)
- rinse with water- 2 seconds
- add 1-2 drops safranin stain-1 minute
- rinse with water- 2 seconds
Why is a thin smear necessary? (3)
to see individual bacteria cells
to prevent stacking
to allow staining to penetrate, but not trap excess stain
what does flaming do?
dries bacteria and prevent it from being washed off
What does the crystal violet do
stains the peptidoglycan layer
Why do we rinse the crystal violet?
to rinse excess stain
what does iodine do?
act as a mordant, fixing the stain in place
what does the decolorizer do?
remove dye from the lipopolysaccharide
why do we rinse the decolorizer?
so it doesn’t remove dye from cells’ capsule on the peptidoglycan layer
