Biochemical Tests for Bacteria Identification

Flashcards covering key vocabulary terms related to biochemical tests for bacterial identification, focusing on enzymes and reactions involved in carbohydrate and amino acid metabolism.

Gelatinase

Enzyme that breaks down the protein gelatin into amino acids.

Positive for Gelatinase

If bacteria have this enzyme, the gelatin will be broken down, so that gelatin is no longer solidified at room temperature, and it appears liquid.

Negative for Gelatinase

If bacteria lack this enzyme, the gelatin will remain solid at room temperature.

Tryptophanase

Enzyme that breaks down tryptophan into pyruvic acid and indole.

Kovac's Reagent

Reagent used as an indicator for indole production; turns pink in the presence of indole.

Cysteine Desulfurase

Enzyme that breaks down cysteine, releasing hydrogen sulfide gas.

Urea

A waste product from protein metabolism that can be broken down to generate energy.

Urease

Enzyme that breaks down urea into ammonia and carbon dioxide.

Phenol Red

Indicator used to detect pH changes in urea hydrolysis; turns pink under alkaline conditions due to ammonia production.

Nitrate Reductase

Enzyme that reduces nitrate (NO3) to nitrite (NO2).

Nitrite Reductase

Enzyme that reduces nitrite (NO2) to ammonia or nitrogen gas.

Nitrate Reagents A and B

Indicators that detect the presence of nitrite.

Zinc Catalyst

Used to catalyze the conversion of nitrate to nitrite.