BIO 150 Microbiology Lab Packet II Flashcards

Here are the flashcards based on the Microbiology Lab Packet II. Learn key terms, vocabulary, and much more related to the Microbiology Lab Packet II with the help of our flashcards quizzes with ease. ​ ​

20 cards   |   Total Attempts: 182
  

Cards In This Set

Front Back
Nonpathogenic Lactose Fermenters (name 3)
E. coli, Enterobacter. Klebsiella
Nonpathogenic Lactose Non-fermenters (name 1)
Proteus
Pathogenic Lactose Non-fermenters (name 2)
Salmonella, Shigella
Question 4
Oxidase test. Direct method used on Pseudomonas aeruginosa and Escherichia coli. Which is the positive result and which is the negative?
Answer 4
Pseudomonas: Positive with a purple/blue color change.
Escherichia: Negative with no color change.
Pseudomonads are obligate aerobes and use an electron transport (or oxidation-phosphorylation) system that includes an enzyme called....
Cytochrome c oxidase

(Cytochrome c oxidase picks up electrons and passes them to a pigment called cytochrome c, which is part of the electron transport pigment system needed for aerobic respiration. This oxidase reagent acts as a false electron donor so if Cytochrome c oxidase is present, it will take the electrons from the oxidase reagent. When the reagent becomes oxidized, by giving away the electrons, it turns purple.)
Question 6
Lactose fermentation tests using Phenol red lactose broth (PR lactose broth) used on Escherichia coli and Salmonella typhimurium.
Answer 6
Escherichia coli: Positive with yellow (acidic) coloration; Positive for gas production.

Salmonella typhimurium: Negative with orange/red (neutral) coloration; Negative for gas production.
Phenol red shifts (pH and coloration)
Alkaline pH -------> cerise pink
Neutral pH --------> red (when lactose is present)
Acidic pH ----------> yellow (positive)

Remember: Most enterics are Lactose fermenters (LF) while potential pathogens will be Lactose nonfermenters (LNF).
Question 8
Lactose fermentation and bile salt tolerance using MacConkey's Agar (MAC), Eosin Methylene Blue Agar (EMB), and Hektoen Enteric Agar (HEA).

On MAC, anything that grows is.....
Bile salt/dye tolerant
Question 9
Lactose fermentation and bile salt tolerance using MacConkey's Agar (MAC), Eosin Methylene Blue Agar (EMB), and Hektoen Enteric Agar (HEA).

On MAC, any growth that is pink or pinkish is a ......
Lactose Fermenter (LF)
Question 10
Lactose fermentation and bile salt tolerance using MacConkey's Agar (MAC), Eosin Methylene Blue Agar (EMB), and Hektoen Enteric Agar (HEA).

On MAC, any growth that is clear or colorless is a ......
Lactose nonfermenter (LNF).
Question 11
Lactose fermentation and bile salt tolerance using MacConkey's Agar (MAC), Eosin Methylene Blue Agar (EMB), and Hektoen Enteric Agar (HEA).

On EMB, anything that grows is.....
Dye tolerant
Question 12
Lactose fermentation and bile salt tolerance using MacConkey's Agar (MAC), Eosin Methylene Blue Agar (EMB), and Hektoen Enteric Agar (HEA).

On EMB, any growth that is dark purple or purplish is a .......
Lactose fermenter
Question 13
Lactose fermentation and bile salt tolerance using MacConkey's Agar (MAC), Eosin Methylene Blue Agar (EMB), and Hektoen Enteric Agar (HEA).

On EMB, any growth that is transparent is a ........
Lactose nonfermenter
Lactose fermentation and bile salt tolerance using MacConkey's Agar (MAC), Eosin Methylene Blue Agar (EMB), and Hektoen Enteric Agar (HEA).

On HEA, anything that grows is .....
Bile salt/dye tolerant
Lactose fermentation and bile salt tolerance using MacConkey's Agar (MAC), Eosin Methylene Blue Agar (EMB), and Hektoen Enteric Agar (HEA).

On HEA, any growth that is bright orange to salmon pink is a ......
Lactose fermenter