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Mannitol Soya Flour (MS) a.k.a. Soya Flour Mannitol (SFM) Medium

Streptomyces coelicolor growing on SFM agar

Mannitol Soya Flour (MS) medium or as it is often called Soya Flour Mannitol (SFM)* medium, is a complex medium used for the routine cultivation of Streptomyces sp. Most species will sporulate well on this medium.

*SFM became routinely used as an acronym for this media to avoid confusion with the plant growth medium Murashige & Skoog medium in the John Innes Media kitchen.


Per Litre:

  • 20 g Mannitol
  • 20 g Soya Flour
  • 20 g Agar
  • 1 L tap water


  1. Dissolve 20g mannitol in 1L tap water
  2. Add 2g soya flour and 2g agar to each 250mL flask
  3. Add 100mL mannitol solution to each flask
  4. Autoclave



Soya flour is available from many health food shops and supermarkets (it is not necessary to purchase the more expensive material from a laboratory supplier).

Liquid MS medium may be made by omitting the agar.

Kieser et al (2000) recommend autoclaving MS twice. Though this is not strictly necessary, the second autoclave cycle can help to break down some of the complex carbohydrates present in the soy flour, making them more readily available to the Streptomyces. Thus, you may observe improved growth and/or development when growing your strains on 2x autoclaved MS.

Streptomyces venezuelae and Streptomyces clavuligerus do not sporulate well on MS medium.

MS may also be used for bioassays, especially if supplemented with e.g. N-acetylglucosamine or sodium butyrate to elicit antibiotic production.


Kieser, T., Bibb, M.J., Buttner, M.J., Chater, K.F. and Hopwood, D.A. (2000) Practical Streptomyces Genetics: John Innes Foundation, Norwich Research Park, Colney, Norwich NR4 7UH, UK

Hobbs, G, Frazer, CM, Gardner, DCJ, Cullum, JA & Oliver, SG 1989, 'Dispersed growth of Streptomyces in liquid culture', Applied microbiology and biotechnology, vol. 31, no. 3, pp. 272-277. https://doi.org/10.1007/BF00258408