Nitrate reductase

Definition

Nitrate reductase is an enzyme that reduces nitrate (NO3-) to nitrite (NO2-) during the process of anaerobic respiration in certain bacteria. It plays a crucial role in nitrogen metabolism and can be used as a diagnostic marker for bacterial infections.

5 Must Know Facts For Your Next Test

1. Nitrate reductase activity is commonly tested in urinary tract infections (UTIs) to identify the presence of nitrate-reducing bacteria.
2. The enzyme is produced by several types of bacteria, including Escherichia coli and Klebsiella species, which are common uropathogens.
3. A positive nitrate reductase test indicates bacterial reduction of nitrate to nitrite, suggesting a bacterial infection.
4. Not all bacteria produce nitrate reductase; therefore, a negative test does not rule out infection.
5. The presence of nitrites in urine can be detected using dipstick tests, which are part of standard UTI diagnostic procedures.

Review Questions

• What role does nitrate reductase play in diagnosing urinary tract infections?
• Which common uropathogenic bacteria produce nitrate reductase?
• Why might a negative nitrate reductase test not definitively rule out a bacterial infection?

Related terms

Anaerobic Respiration:

A form of respiration that occurs without oxygen, where organisms convert energy through the reduction of nitrates.

Escherichia coli:

A type of bacteria commonly found in the intestines and a frequent cause of urinary tract infections.

Nitrite Test: A diagnostic tool used to detect the presence of nitrites in urine, often indicative of bacterial infection.