Lab Final

Question 1

Voges-Proskauer Test

Answer 1

detect production of 2,3- butanediol from glucose fermentation (pH neutral end product). POS = red NEG = clear

Question 2

Simmons Citrate slant

Answer 2

Determines the utilization of citrate. POS = pH indicator turns from green to blue

Question 3

Kliger’s Iron Deep Slant

Answer 3

H2S production from cysteine. POS = black butt

Question 4

Urea Broth

Answer 4

Production of urease. POS = pink medium

Question 5

Motility

Answer 5

TTC turns red when reduced due to cell growth.
POS = pink throughout NEG = sharp line

Question 6

Phenol Red Broths

Answer 6

Ability to ferment carbs; acid byproduct. POS = red to yellow broth

Question 7

Indole

Answer 7

Degradation of tryptophan. Add Kovac’s reagent. POS = red ring NEG = yellow ring

Question 8

Phenylalanine Deaminase

Answer 8

Deamination of phenylalanine. Ferric chloride reacts with phenylpyruvic acid. POS = turns green NEG = yellow

Question 9

Nitrate Reduction

Answer 9

POS = Red. NEG = colorless. Add Zn to determine if true negative.

Question 10

EMB

Answer 10

selective media, allows for growth of gram negative. differential for lactose fermentation. POS lactose = colonies turn dark purple and may produce metallic green sheen

Question 11

Oxidase

Answer 11

determines presence of cytochrome C oxidase. POS = turns purple within 30 seconds

Question 12

Catalase

Answer 12

breakdownn H2O2 into water and oxygen. POS = bubbling