Starch Casein Agar (SCA) – Composition, Principle, Uses, Preparation and Result Interpretation

Starch Casein Agar (SCA) is used for the detection of saccharolytic marine bacteria and mostly actinomycetes. Actinomycetes are a fungi-like bacteria forming long filaments that stretch through the soil. They are large group of gram positive filamentous and/ or branching bacilli. Actinomycetes have been isolated from terrestrial sources, although the first report of mycelium forming actinomycetes being recovered from marine sediments appeared several decades ago. Marine sediments are known potential sources for isolation of novel actinomycetes yielding new products and are recognized as source of novel antibiotic and anticancer agents. The actinomycetes have an extensive impact on the environment by decomposing and transforming a wide variety of complex organic residues. Actinomycetes thus represent an important group of microbes found in environment and plays significant role not only in therapeutic applications but also on recycling of organic matter.

Composition of Starch Casein Agar

Ingredients Gms / Litre
Soluble starch 10.00
Casein (Vitamin Free) 0.30
KNO3 2.00
MgSO4.7H2O 0.05
K2HPO4 2.00
NaCl 2.00
CaCO3 0.02
FeSO4.7H2O 0.01
Agar 18.00

Filtered Sea Water (Distilled Water) = 1000 ml

pH ( at 25°C) 7.0 ± 0.1

HIMEDIA Starch Casein Agar Composition

Ingredients Gms / Litre
Casein Powder 1.00
Starch 10.00
Sea Water 37.00
Agar 15.00

Distilled Water = 1000 ml

pH ( at 25°C) 7.2±0.2

Principle of Starch Casein Agar

This medium has starch as the complex carbohydrate source and casein as nitrogen source. The salts of seawater provides complex ionic sources that makes the medium suitable for marine microbial flora and also buffers the medium.

Uses of Starch Casein Agar

  1. It is used for the detection of saccharolytic marine bacteria.
  2. It is used for the isolation of actinomycetes.

Preparation of Starch Casein Agar

  1. Suspend 63.0 grams of Starch Casein Agar in 1000 ml distilled water.
  2. Heat to boiling to dissolve the medium completely.
  3. Sterilize by autoclaving at 15 lbs pressure (121°C) for 15 minutes.
  4. Mix well and pour into sterile Petri plates.

Result Interpretation on Starch Casein Agar

Actinomycetes: Off-white to yellow colored homogeneous free flowing powder.

Actinomycetes on Starch Casein Agar (SCA)


  1. Balakrishna, A. Shiva Shanker and Pavan Kumar Pindi. Isolation of Phosphate Solibulizing Actinomycetes from Forest Soils of Mahabubnagar District. IOSR Journal of Pharmacy. Mar.-Apr. 2012, Vol. 2(2) pp: 271-275.
  2. Starch Casein Agar. HiMedia Laboratories Pvt. Ltd.
  4. Starch Casein Agar, Culture Media. My Bio Source.
  5. Mojtaba Mohseni, Hamed Norouzi, Javad Hamedi, Aboulghasem Roohi. Screening of Antibacterial Producing Actinomycetes from Sediments of the Caspian Sea. IJMCM Original Article Spring 2013, Vol 2, No 2.

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