SFM
Soy Flour Mannitol Medium
Soy Flour Mannitol (SFM) medium, also called Mannitol Soy Flour (MS) medium, is a complex medium used for the routine cultivation of Streptomyces sp. Most will sporulate well on this medium.
Preparation
Per Litre:
- 20g Mannitol
- 20g Soy Flour
- 20g Agar
- 1L with tap water
Instructions
- Dissolve 20g mannitol in 1L tap water
- Add 2g soy flour and 2g agar to each 250mL flask
- Add 100mL mannitol solution to each flask
- Autoclave
Uses
- Routine growth of Streptomyces sp.
- Conjugations
- Preparing spore stocks
Notes
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 SFM medium may be made by omitting the agar.
Kieser et al (2000) recommend autoclaving SFM 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 SFM.
Streptomyces venezuelae does not sporulate well on SFM medium.
References
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
