Lab 8: Oxidative and Fermentation Tests Overview

Oxidative test

Determines if organism uses oxygen for respiration.

Fermentation test

Identifies if organism ferments sugars for energy.

O/F Glucose test

Differential medium for oxidative or fermentative organisms.

Glucose

Simple sugar used in fermentation tests.

Peptone

Source of nitrogen in O/F glucose test.

Brom-thymol blue

pH indicator that turns yellow in acidity.

Anaerobic condition

Environment without oxygen for fermentation testing.

Aerobic condition

Environment with oxygen for respiration testing.

E. coli

Facultative anaerobe used as control organism.

Pseudomonas aeruginosa

Strict aerobe used for oxidative testing.

Durham tube

Detects gas production in fermentation tests.

Phenol red

pH indicator for acid detection in fermentation.

Mixed acid fermentation

Produces lactic, acetic, and formic acids from glucose.

MR-VP medium

Used for mixed acid and butanediol fermentation tests.

2,3-Butanediol fermentation

Produces neutral end product from glucose fermentation.

Barritt's reagent

Detects 2,3-butanediol in fermentation tests.

Citrate fermentation

Breaks down citrate to produce various acids.

Simmons citrate agar

Medium for testing citrate utilization by bacteria.

Cytochrome oxidase test

Detects cytochrome oxidase enzyme in aerobic bacteria.

Catalase test

Detects catalase enzyme that breaks down hydrogen peroxide.

Nitrate reduction

Bacteria reduce nitrates to nitrites or nitrogen gas.

Beef extract medium

Used for nitrate reduction tests with potassium nitrate.

Nitrate reagent A and B

Reagents that detect nitrite presence with color change.

Gas end products

N2O or N2 produced from nitrate reduction.

Acid production

Indicated by color change in fermentation tests.