Microbio Lab Quiz 3

General

Growth media with a non-specific purpose; wide range

Selective

Growth media that allows the growth of some kinds of organisms and restricts growth of others

Differential

Growth medium that yield specific and observable change/characteristic associated with certain kinds of bacteria

Triple Sugar Iron

Growth medium that determines ability to ferment specific sugars, produce gas, and produce hydrogen sulfide

Glucose Fermentation

Top is red, bottom is yellow

All three sugars fermented

All yellow

Gas produced

Bottom pushed up/air bubble

Hydrogen Sulfide production

Yellow bottom, to black, to red

Phenol red

pH indicator

Acidic

Turns Yellow

Basic

Turns Red

Motile

Organisms swim out

Non Motile

Organisms remain trapped in the medium

Oxidase Test

Tests the presence of cytochrome c

Cytochrome C

Intracellular oxidase enzyme; oxidizes the reagent

Starch Hydrolysis

Tests for presence of amylase

Positive

Clear zone around growth; “halo“

Negative

All Black

Carbohydrate Test

Determines if specific carbohydrate is fermented