Final

Question 1

Obligate aerobes

Answer 1

require oxygen and will only grow at the top of the medium

Question 2

Obligate anaerobes

Answer 2

are harmed by oxygen and will only grow at the bottom of the medium

Question 3

Facultative anaerobes

Answer 3

grow in the presence and absence of oxygen and are more prevalent at the top of the broth (where the oxygen is) but will grow throughout the medium

Question 4

Microaerophiles

Answer 4

only survive in less than atmospheric levels of oxygen but still need a small amount of oxygen. They will grow from the middle to the upper middle region of the medium.

Question 5

Aerotolerant anaerobes

Answer 5

don’t require oxygen but aren’t harmed by it and will grow uniformly through the medium.

Question 6

Thioglycollate medium

Answer 6

special broth that has a gradient of oxygen levels. There is a dye called resazurin in it that is pink when oxidized and colorless when it is reduced.

Question 7

ubiquitous

Answer 7

means they can be found everywhere on our planet

Question 8

streak plate method

Answer 8

a way to separate bacteria in a mixed culture in order to isolate and subculture single species/types of bacteria into a pure culture

Question 9

anaerobic jar

Answer 9

permits the growth of anaerobic and facultative bacteria through the use of gas packets

Question 10

presence of CO2 (anaerobic jar)

Answer 10

Indicator turns from pink to yellow

Question 11

Blood agar plates

Answer 11

test for pathogenic bacteria

Question 12

Hemolysins are exotoxins that are able to destroy red blood

Answer 12

Hemoglobin

Question 13

blood agar is used to test bacteria for

Answer 13

ability of hemolysis.

Question 14

Beta-hemolysis (β-hemolysis)

Answer 14

complete destruction of red blood cells, and is indicated by a clearing around the growth

Question 15

Alpha-hemolysis (α-hemolysis)

Answer 15

damaging of the red blood cells (not complete destruction, only partial) and is indicated by a greenish discoloration.

Question 16

Gamma-hemolysis (γ-hemolysis)

Answer 16

actually nonhemolysis and this is indicated simply by normal growth with no clearing in the agar.

Question 17

Nitrate broth

Answer 17

differential medium. It is used to determine if an organism is capable of reducing nitrate (NO3- ) to nitrite (NO2-)or other nitrogenous compounds

Question 18

Simmons citrate medium

Answer 18

used in this test and it contains sodium citrate as the only carbon-containing compound source and ammonium ions as the only nitrogen source.

Question 19

pH increases,

Answer 19

turns blue, which indicates the bacteria are able to utilize the citrate.

Question 20

What significance does this test have in relation to microbial metabolism?

Answer 20

The significance of this test shows that only bacteria that had the ability to create enzymes citrate-permease were able to growth, as these enzymes allow citrate to be transported throughout the cell. The microbial metabolism is represented by the change in color (blue) or the indicator of growth.

Question 21

Voges-Proskauer tests

Answer 21

able to ferment glucose, but then convert the acid products to acetoin and 2,3-butanediol

Question 22

positive VP test is indicated by

Answer 22

Red

Question 23

Negative VP test is indicated by

Answer 23

Copper or no change in color

Question 24

mixed acid fermentation

Answer 24

produce more acid

Question 25

MR-VP test is used

Answer 25

determine some of those products. (convert the glucose to acids.)
MR-VP broth includes peptone, glucose, and a phosphate buffer.

Question 26

Amylase

Answer 26

(an enzyme released from the bacteria into its surroundings) that breaks starch by cleaving large starch

Question 27

Iodine

Answer 27

turns a blue/black color when it comes into contact with starch

Question 28

amylase is present

Answer 28

clearing in the agar where the iodine did not react with any starch.

Question 29

Kirby-Bauer method

Answer 29

disk-diffusion method, is a method used to test the effectiveness of antimicrobials against pathogenic microorganisms