Lab Practicum

Question 1

Obligate aerobe

Answer 1

Require oxygen to survive and grow

Question 2

Obligate anaerobe

Answer 2

Often bacteria, can only survive in environments without oxygen

Question 3

Facultative anaerobes

Answer 3

Organisms, usually bacteria, that can grow and produce energy with or without oxygen

Question 4

Microaerophiles

Answer 4

Requires environments containing lower levels of oxygen

Question 5

Broth (liquid) or solid media?

Answer 5

Broth is a liquid medium containing water and nutrients

Solid is a broth which has been solidified by the addition of AGAROSE, % determine rigidity

Question 6

Synthetic or non synthetic media?

Answer 6

Synthetic contains purified chemicals. 100% of ingredients will have exact chemical composition and formula. Ex: glucose, tryptophan, sodium citrate, mannitol, oleic acid, potassium nitrate, ammonium , etc

Non synthetic contains at least one ingredient that is NOT purified or characterized and does NOT have exact formula/comp. Ex: digested proteins, peptone, animal/plant extracts, beef

Question 7

General purpose or minimal?

Answer 7

General: numerous ingredients and will allow many different microbes to grow

Minimal: minimal # of ingredients that will allow an organism to grow

Question 8

Enriched media

Answer 8

Fastidious microbes may require many unknown and complex growth gators in order to grow. This problem may be solved by adding extra complex ingredients (blood, serum, yeast extract, brain infusions)

Question 9

Reducing media

Answer 9

Obligate anaerobes will not grow in presence O2 and microaerophiles will tolerate only small amount of oxygen. A reducing media contains a chemical ingredient that will deplete or remove oxygen. Thioglycollate, thiosulfate, & chemicals rich in sulfur such as cysteine and cystine

Question 10

Buffered media

Answer 10

Grow optimally at a specific range of pH values. Their growth is often inhibited by the dramatic pH changes resulting from microbial metabolism. To prevent this problem, buffers are added to stabilize the medium pH. Mono basic and diabetic phosphate buffers are often added tg. Ex: KH2PO4/K2HPO4

Question 11

Selective and differential media?

Answer 11

Selective: encourage growth of some pathogens but discourage or inhibit growth of others Ex: salt, low/high pH, dyes, narrow spectrum antibiotics, disinfectants, antibacterial, and bile salts
Differential: allow more than one species of interest to grow but hey are morphological my distinguishable from one another. Ex: mannitol, fermentation, lactose fermentation, blood hemolysis, and dyes such as eosin-meth blue

Question 12

Staph is what for catalyze test

Answer 12

Positive

Question 13

Strep is what for catalyze test

Answer 13

Neg

Question 14

Catalyze test

Answer 14

detects the enzyme catalase, which protects bacteria from the toxic effects of hydrogen peroxide by breaking it down into harmless water and oxygen.

Question 15

Where would obligate aerobe be found?

Answer 15

Slant since they need O2

Question 16

Where would obligate anaerobe be found?

Answer 16

Thiogly. Broth since they don’t need O2

Question 17

Where would facilative anaerobe be found?

Answer 17

Slant/tall/broth since they don’t have to have O2

Question 18

Where would microaerophile be found

Answer 18

Tall/broth since they need a small amount of O2

Question 19

What medium is used for catalyze test?

Answer 19

Solid medium