Soil Microbes, Nitrogen Cycle, Plaque Assay, & Water Testing

Flashcards covering key terms and definitions related to soil microbes, the nitrogen cycle, plaque assays, and water testing.

Soil Microbes

Microorganisms such as bacteria, fungi, and protists that play essential roles in soil health by participating in nutrient cycling and decomposition.

Nitrogen Fixation

The process through which microbes convert nitrogen gas (N2) into ammonia (NH3).

Ammonification

The process by which microbes convert organic nitrogen (from amino acids) into ammonia.

Nitrification

The microbial process of oxidizing ammonium ions (NH4+) into nitrites (NO2-) and nitrates (NO3-).

Denitrification

The process by which nitrates are reduced and nitrogen gas (N2) is released into the atmosphere.

Durham Tube

A tube used in microbiology to detect gas production during fermentation; a positive result is indicated by the presence of a bubble.

Peptone Broth

A type of nutrient medium containing partially hydrolyzed proteins used to cultivate bacteria, serving as a source of amino acids.

Plaque Assay

A method used to quantify the number of bacteriophages in a sample by counting clear zones (plaques) on a bacterial lawn.

Agar Overlay Method

A plating technique where a mixture of liquid agar and culture is poured over solid agar to allow for the growth of microorganisms.

Fecal Coliforms

Gram-negative bacteria, such as E. coli, that are indicators of fecal contamination in water.

Potable Water

Water that is safe to drink and contains virtually no coliforms.