Lab quiz 3 Microbiology

Gelatin is a

protein and is hydrolyzed to obtain amino acid building blocks.

How did you know that the GasPak was truly an anaerobic environment?

The indicator, reazurin, is pink in the presence of oxygen but colorless in its absence.

When positive, the Kovac's reagent has reacted with what chemical?

indole

A positive reaction with the Kovac's reagent on SIM medium indicates that _____ has been hydrolyzed.

tryptophan

How would you know that you were dealing with a strict aerobe in FTM?

It would only grow along the top of the tube of medium

In the citrate test you are testing whether your organism can use sodium citrate as the sole _______ source.

 

carbon

The strongest lactose fermenters will appear purple on EMB.

False, the strongest lactose fermenters will appear metallic green.

What color indicates a positive oxidase test?

purple

The small upside down test tube contained in the fermentation broth tubs is there to

check for gas production

When phenol red turns yellow it means the medium has turned

acidic

What pattern of growth does a facultative anaerobe show in FTM?

growth throughout tube

Vogues Proskauer tests for acetoin and is a test for which fermentation pathway?

butanediol

What molecule is produced by the chemical packet in the anaerobe jar that is responsible for reacting with and thus removing oxygen gas?

hydrogen gas H2

What is the indicator of oxygen diffusion in the fluid thioglycollate medium?

resazurin

The indicator in the carbohydrate test tubes was

phenol red