Quiz #3

Question 1

purpose of Casein Hydrolysis Test

Answer 1

to ID bact. that produce caseinase

Question 2

function of caseinase

Answer 2

breaks down casein

Question 3

medium for Casein Hydrolysis Test and its color

Answer 3

milk agar (white due to casein)

Question 4

procedure for Casein Hydrolysis Test

Answer 4

1) streak a line of org onto Milk Agar Plate
2) incubate at 37°C for ~48 hours

Question 5

theory for Casein Hydrolysis Test

Answer 5

Casein (white protein)
-> caseinase ->
Amino Acids (clear)

Question 6

Casein Hydrolysis Test results

Answer 6

+ = clearing around the streak line
- = no clearing around the streak line

Question 7

purpose of Gelatin Hydrolysis Test

Answer 7

to ID bact. that produce gelatinase

Question 8

function of gelatinase

Answer 8

breaks down gelatin

Question 9

medium for Gelatin Hydrolysis Test and its solidifying agent

Answer 9

Nutrient Gelatin Deep
SA = gelatin

Question 10

Gelatin Hydrolysis Test procedure

Answer 10

1) inoculate org into Nutrient Gelatin Deep
2) Incubate at 25°C for >=48 hours

Question 11

Gelatin Hydrolysis Test theory

Answer 11

Gelatin (solid at room temp)
-> gelatinase ->
Amino Acids (liquid)

Question 12

Gelatin Hydrolysis Test results

Answer 12

+ = liquid
- = solid

Question 13

Purpose of Starch Hydrolysis Test

Answer 13

to ID bact. that produce amylase

Question 14

amylase function

Answer 14

breaks down starch

Question 15

Starch Hydrolysis Test medium

Answer 15

Starch Agar Slant

Question 16

Starch Hydrolysis Test procedure

Answer 16

1) inoculate org onto Starch Agar Slant
2) incubate at 37°C for ~48 hours

• after incubation, add Iodine -> binds to starch -> blue/black coloring

Question 17

Starch Hydrolysis Test theory

Answer 17

Starch (colorless)
-> Amylase ->
Simple Sugars (colorless)

Question 18

Which is a positive result for the Starch Hydrolysis Test and which is the negative

Answer 18

Left is positive (colorless portion)
right is negative (all blue)