Bacillus Identification and Transformation

Question 1

What are the ingredients in mannitol salt agar? Is MSA selective, differential, or both?

Answer 1

7.5% NaCl, carbohydrate substrate mannitol, and pH indicator phenol red. MSA is both selective (for halotolerant organisms) and differential (for mannitol fermentation)

Question 2

What are the ingredients in Bile Esculin Agar slants? What does a positive reaction to esculin hydrolysis look like?

Answer 2

Bile salts, esculin, ferric ammonium citrate, and beef and gelation extracts. A positive reaction looks like 50% or more of black precipitate

Question 3

What are the ingredients in starch media?

Answer 3

Starch

Question 4

What enzymes degrade starch?

Answer 4

Amylase and maltase

Question 5

What does starch hydrolysis look like on a starch plate?

Answer 5

Clearing around the growth of the microorganism

Question 6

What reagent needs to be added to the starch plate?

Answer 6

Gram’s Iodine

Question 7

What is the lipid substrate in lipid media?

Answer 7

Tributyrin

Question 8

Name the enzymes that degrade lipids

Answer 8

Lipase

Question 9

What does lipid hydrolysis look like on a lipid plate?

Answer 9

Clearing around the growth of the organism

Question 10

What are the ingredients in casein media?

Answer 10

Casein

Question 11

What enzymes degrade casein?

Answer 11

Protease and or casease

Question 12

What does casein hydrolysis look like?

Answer 12

Clearing around the growth of the microorganism

Question 13

What is the peptonization process when it comes to casein?

Answer 13

Enzymes degrade casein, the protein is broken into peptones, then into polypeptides, then dipeptides, and finally into amino acids

Question 14

What is the name of the enzyme that hydrolyzes gelatin?

Answer 14

Gelatinase

Question 15

Why was media containing ampicillin used to select for transformants of E.coli?

Answer 15

E.coli is resistant to ampicillin