Lecture 2 (cover videos A & B)
Abbreviations:
Tuesday, January 12, 2021 10:21 PM
Ex. = for example,
b/w = between
b/c = because
w/ = with
Bacterial Identification (week 1 notes continued)
LECTURE PRACTICE PROBLEMS
• (After we have isolated bacteria from week 1) Are our single colonies a pure culture?
Catalase/Oxidase tests lets you determine aerobe versus anaerobe. Y or N? No! Whether a
No, bacteria just have enough space on media to grow independently.
bacterium is an anaerobe or aerobe is NOT dependent on these tests! That is determined
• Pure cultures can be identified when all single colonies look similar.
by whether the bacterium can grow without OR with oxygen. -> You cannot assume
• Isolation -> confirm pure culture -> complete Gram stain of the unknowns -> ABA DABA
bacteria is an anaerobe/aerobe from these tests. The catalase/oxidase tests do not tell us if the
tests
organism utilizes O2 in its metabolic pathway.
• ABA DBA test: aides in identifying the family/genus of unknown bacteria. Includes:
○ Catalase test, oxidase test, phenol red test, minimal media test, fluorescent
What is the ABA DABA designation?
pigment test, motility test.
1. Isolate A - Gram positive, rod shaped, oxidase negative, catalase positive, pigment
• How to read any scientific paper:
negative, grows on minimal media, phenol red negative, non-spore forming, motile ->
○ What is the main question the authors are asking (purpose of the paper)?
+AAB. Assumed it was an obligate aerobe b/c it possesses catalase (breaks down O2
○ What is the answer to that question?
radicals by-producted from the ETC) and it does not undergo fermentation (cannot
○ For each figure –What is the purpose of the figure?–What do the authors learn and
ferment glucose).
how does that tie into the main question?
2. Isolate B - Gram negative, cocci, oxidase positive, catalase positive, pigment negative,
does not grow on minimal media, phenol red positive, non-motile -> -ACB. Can ferment
• Scientific Paper 1:
glucose, BUT also possesses cytochrome c oxidase and expresses catalase-- most
○ Spectrophotometer: measures growth of a bacteria. Gives an optical density-- how
likely grows w/ O2.
many cells are detected when light passes thru a sample. Ex. The higher the
Abbreviations:
Tuesday, January 12, 2021 10:21 PM
Ex. = for example,
b/w = between
b/c = because
w/ = with
Bacterial Identification (week 1 notes continued)
LECTURE PRACTICE PROBLEMS
• (After we have isolated bacteria from week 1) Are our single colonies a pure culture?
Catalase/Oxidase tests lets you determine aerobe versus anaerobe. Y or N? No! Whether a
No, bacteria just have enough space on media to grow independently.
bacterium is an anaerobe or aerobe is NOT dependent on these tests! That is determined
• Pure cultures can be identified when all single colonies look similar.
by whether the bacterium can grow without OR with oxygen. -> You cannot assume
• Isolation -> confirm pure culture -> complete Gram stain of the unknowns -> ABA DABA
bacteria is an anaerobe/aerobe from these tests. The catalase/oxidase tests do not tell us if the
tests
organism utilizes O2 in its metabolic pathway.
• ABA DBA test: aides in identifying the family/genus of unknown bacteria. Includes:
○ Catalase test, oxidase test, phenol red test, minimal media test, fluorescent
What is the ABA DABA designation?
pigment test, motility test.
1. Isolate A - Gram positive, rod shaped, oxidase negative, catalase positive, pigment
• How to read any scientific paper:
negative, grows on minimal media, phenol red negative, non-spore forming, motile ->
○ What is the main question the authors are asking (purpose of the paper)?
+AAB. Assumed it was an obligate aerobe b/c it possesses catalase (breaks down O2
○ What is the answer to that question?
radicals by-producted from the ETC) and it does not undergo fermentation (cannot
○ For each figure –What is the purpose of the figure?–What do the authors learn and
ferment glucose).
how does that tie into the main question?
2. Isolate B - Gram negative, cocci, oxidase positive, catalase positive, pigment negative,
does not grow on minimal media, phenol red positive, non-motile -> -ACB. Can ferment
• Scientific Paper 1:
glucose, BUT also possesses cytochrome c oxidase and expresses catalase-- most
○ Spectrophotometer: measures growth of a bacteria. Gives an optical density-- how
likely grows w/ O2.
many cells are detected when light passes thru a sample. Ex. The higher the
