Bacteria

Question 1

What is the optimum temp range for psychrophiles?

Answer 1

-10 to 20, with an optimum at 10

Question 2

What is the optimum temp range for psychrotrophs?

Answer 2

0 to 30, with an optimum at 20-ish

Question 3

What is the optimum temp range for mesophiles?

Answer 3

10 to 50, with an optimum at 37-ish

Question 4

What is the optimum temp range for thermophiles?

Answer 4

40-70, with an optimum at 60

Question 5

What is the optimum temp range for hyperthermophies?

Answer 5

65-100, with an optimum 85-100 ish

Question 6

What are the types of oxygen requirements, and where would they be found growing in a tube?

Answer 6

microaerophilic anaerobe, grows mostly throughout the them, but especially in the middle of teh tube; fac. anaerobe grows all throughout the tube; obligate anaerobe grows only at the bottom; obligate aerobe grows only at the top; aerotolerant anaerobe mostly grows at the bottom;

Question 7

How does an anaerobic chamber work?

Answer 7

a packet with sodium bicarb and sodium borohydride binds the oxygen (?) and makes CO2; an indicator (methylene blue) shows when O2 has been removed from the environment

Question 8

What are the types of media?

Answer 8

Selective, differential, enrichment

Question 9

Desrcribe a MacConkey agar plate

Answer 9

Selective and differential; selects for gram -ve bacteria because ofn CV and bile salts, and differentiates between lactose fermenters and non-fermenters (yellow agar turns purple for Lac +)

Question 10

Describe an MSA plate

Answer 10

Selective and differential; Selects for halophiles; differentiates between mannitol (a sugar-alcohol) fermenters and non-fermenters; useful for detecting Staph aureus

Question 11

Describe a blood agar plate

Answer 11

Enrichment and differential; 5-10% sheep’s blood, differentiates between different types of hemolysis (bursting of blood cells to release iron); hemolysis may be enhanced in low-oxygen environments

Question 12

Describe a Sab’s Agar plate

Answer 12

Similar to nutrient agar but has high amount of glucose; sugar and acidic pH selects for yeasts and molds

Question 13

Describe a SIM deep

Answer 13

Differential x3; if H2S is produced (sulfur reduction), it will react with Ammonium Iron (II) Sulfate and turn the tube black; if tryptophan is metabolized (producing indole), then it will react with kovac’s reagent, turning the tube red; if organisms are motile, they will spread out and turn the tube cloudy

Question 14

What is the purpose of the oxidase test?

Answer 14

To see if organisms have the enzyme cytochrome 3 oxidase, which indicates they can use oxygen to produce ATP; disks or strips are wetted, a small colony is applied, and if they turn blue, then the organisms test positive for Cyt 3 Ox

Question 15

What are the nucleic acid inhibitors?

Answer 15

Rifampin and rifamyci; most useful against mycobacterium; inhibits mRNA synthesis; highly permeable into cells and cell walls; and quinilones–inhibits DNA gyrase and thus DNA replicatio; broad spectrum; ciprofloxin is most well known

Question 16

What are the folic acid inhibitors?

Answer 16

sulfonamides; block the enzymes used to generate folic acid which is needed for thymine and uracil; we take in dietary folic acid s these do not affect us;

Question 17

What are the modes of resistance

Answer 17

1. drug modification or destruction (beta-lactamases for penicillin); 2. Pathway protection (synthesis of false targets for tetracycline) 3. Target alteration (single mutation in ribosome to prevent binding); 4. Rapid efflux (create ways to pump drugs out of the cell); 5. Alternative pathways (being able to take in dietary folic acid rather than make it);