Activity 9: BIOCHEMICAL TESTS AND REACTIONS

Question 1

For CHO fermentation
Air space in the smaller test tube indicates GAS production in LACTOSE BROTH

Answer 1

DURHAM FERMENTATION TUBE

Question 2

Bacteria used in converting one molecule of GLUCOSE into two molecules of LACTIC ACID
Used to ferment MILK and milk products

Answer 2

HOMOLACTIC FERMENTERS

Question 3

Yield CARBON DIOXIDE and ETHANOL + LACTIC ACID
leuconostoc, weissella

Answer 3

HETEROLACTIC FERMENTERS

Question 4

Pathway of GLYCOLYSIS
Used in HOMOLACTIC acid bacteria to produce LACTIC ACID
Used by SACCHAROMYCES (YEAST) to produce ETHANOL and CARBON DIOXIDE

Answer 4

EMBDEN-MEYERHOF PATHWAY

Question 5

Catabolize GLUCOSE to PYRUVATE
Occurs only in PROKARYOTES
Generally utilized by GRAM NEGATIVE BACTERIA

Answer 5

ENTNER-DOUDOROFF PATHWAY

Question 6

3 SUGARS IN TSI - TRIPLE SUGAR IRON

Answer 6

LACTOSE
SUCROSE
GLUCOSE

Question 7

Permits early detection of COLIFORM bacteria that ferment SUCROSE more rapidly than LACTOSE

Answer 7

TSI - TRIPLE SUGAR IRON

Question 8

TSI RESULT: RED COLOR INTERPRETATION?

Answer 8

Alkalinization/Non fermentation of the sugars

Question 9

TSI RESULT: YELLOW COLOR INTERPRETATION?

Answer 9

Acid Production

Question 10

TSI RESULT: GAS PRODUCTION INTERPRETATION?

Answer 10

Fermentation/Metabolic Activity

Question 11

TSI RESULT: BLACK PRECIPITATE IN THE BUTT INTERPRETATION?

Answer 11

Reaction between iron salts of ferrous sulfate and ferric ammonium citrate forming an insoluble black precipitate of ferrous sulfide

Question 12

TSI RESULT: K/A INTERPRETATION?

Answer 12

Alkaline Slant, Acid Butt

Question 13

TSI RESULT: K/A INTERPRETATION?

Answer 13

Acid Slant, Acid Butt

Question 14

INDOLE Test Purpose?

Answer 14

detects Production of INDOLE

Question 15

REAGENTS For INDOLE?

Answer 15

Kovac’s Reagent

Question 16

INDOLE Test Results

Answer 16

Positive = Pink
Negative = Yellow

Question 17

METHYL RED Test Purpose?

Answer 17

isolate organisms that can produce a strong ACID from glucose

Question 18

REAGENTS For METHYL RED?

Answer 18

Methyl Red

Question 19

METHYL RED Test Results

Answer 19

Positive = Red
Negative = Yellow

Question 20

VOGES-PROSKAUER Principle?

Answer 20

Formation of ACETYL METHYL CARBINOL ACETOIN from glucose fermentation

Question 21

REAGENTS For VOGES-PROSKAUER?

Answer 21

Alphanaphthol and KOH

Question 22

VOGES-PROSKAUER Test Results

Answer 22

Positive = Red/Brown
Negative = Yellow

Question 23

CITRATE Test Purpose?

Answer 23

test an ability of organism to use citrate as its sole source of carbon

Question 24

REAGENTS For CITRATE Test

Answer 24

Bromothymol Blue

Question 25

CITRATE TestTest Results

Answer 25

Positive = Blue
Negative = Green