Скачать или смотреть Plate Count Agar PCA I Purpose and Composition I General Purpose Media I Bacterial Culture Media

Plate Count Agar (PCA) is a general-purpose bacterial culture medium, composed of tryptone, yeast extract, glucose, and agar, mainly used for the enumeration of viable bacteria (CFU counts) in food, water, and environmental microbiology.
Plate Count Agar (PCA) is a general-purpose, non-selective solid medium.

Specifically designed for the enumeration of viable microorganisms in food, water, milk, and other samples.

Recommended by APHA (American Public Health Association) and ISO standards for total viable bacterial count.

2. Purpose / Uses

Used for standard plate count method (SPC) → to determine the colony-forming units (CFU/ml or CFU/g) in a sample.

Widely applied in food microbiology, dairy microbiology, and water testing.

Useful for monitoring hygiene, sanitation, and quality control in industries.

Suitable for non-fastidious bacteria (not for fastidious or pathogenic organisms).

Common in teaching labs for microbial enumeration experiments.

3. Composition (per liter, typical)

Tryptone (pancreatic digest of casein) – 5 g (source of nitrogen, peptides, amino acids).

Yeast extract – 2.5 g (provides vitamins, growth factors).

Glucose (dextrose) – 1 g (energy source).

Agar – 15 g (solidifying agent).

Distilled water – 1 L

Final pH – 7.0 ± 0.2 at 25 °C

4. Principle

Tryptone + yeast extract provide essential nutrients for microbial growth.

Glucose serves as an immediate energy source.

Agar solidifies the medium for colony isolation and enumeration.

Supports the growth of a broad range of non-fastidious aerobic and facultative anaerobic bacteria, making it ideal for total viable count.

5. Summary

Plate Count Agar (PCA):

Purpose: General-purpose medium for enumeration of viable microorganisms in food, water, and other samples.

Composition: Tryptone, yeast extract, glucose, agar, distilled water.

Key Point: Standard medium for colony counts (CFU/ml or g) in quality control and microbiology labs.

6. Key Points

PCA = standard plate count medium.

Used in food, dairy, and water microbiology.

Enumerates total viable bacterial population.

Not selective → does not differentiate or enrich fastidious organisms.