Denitrification and Nitrate Reduction

These flashcards cover key concepts related to denitrification and the nitrate reduction test, providing definitions for important terms and processes.

Denitrification

Reduction of nitrate to nitrite to nitrogen gas.

Anaerobic respiration

A type of respiration that occurs without oxygen.

Nitrate Broth

A medium used to determine the ability of microbes to reduce nitrate.

Potassium nitrate

The nitrogen source found in nitrate broth.

Nitrate reduction

The process of converting nitrate to nitrite or nitrogen gas.

Nitrate A + B reagents

Chemical indicators used to detect nitrite in the nitrate reduction test.

Zinc

A metal used to confirm the presence of unreduced nitrate by turning red.

Durham tube

An indicator used to detect gas production during denitrification.

Complete denitrification

Indicated by the presence of gas (N₂) in the Durham tube.

Partial reduction

Indicated by red coloration after adding Nitrate A + B reagents.

No reduction

Indicated by red coloration after the addition of zinc.

By-product detected by A+B

Nitrite.

Gas [+]

Presence of N₂ indicates complete denitrification.

Nitrite [+]

Presence of nitrite indicates partial reduction.

Nitrate [+]

Presence of nitrate indicates no reduction.