Motility medium
From BugwoodWiki
Contents |
Purpose
Allows motile bacteria to diffuse out into the medium for detection of motility of bacteria.
Ingredients
| Ingredient | 250 ml | 100 ml |
|---|---|---|
| Distilled water | 250 ml | 100 ml |
| Bacto tryptose | 2.5 g | 1 g |
| NaCl | 1.25 g | 0.5 g |
| Bacto agar | 1.25 g | 0.5 g |
Instructions
- Combine ingredients and heat with frequent agitation to melt agar and mix thoroughly.
- Dispense melted agar mixture into tubes and autoclave at 121° C for 15 minutes. Let cool.
- Inoculate with a straight needle by stabbing vertically to produce a sharply delineated line.
- Incubate plant pathogenic bacteria at 27 °C for up to 5 days. For Enterobacteriaceae, excluding Erwinia, incubate at 37 °C for 2 days. If negative, incubate at 22-25 °C for an additional 5 days.
Notes
- Bacterial motility can be observed from examination of the tubes following incubation.
- Growth spreads out from the line of inoculation if the bacteria are motile.
- Growth of non-motile bacteria only occurs along the stab line.
- The hanging drop technique works fine for bacteria that are relatively motile, but may not distinguish those that move weakly.
- The slushy agar of the motility medium allows motile bacteria to diffuse out into the medium.
- This test is not typically used for plant pathogenic bacteria because only the coryneform bacteria are non-motile.
References
- Difco Manual, 10th Ed. 1984. Difco Laboratories, Detroit, MI. 1155 pp.
- Edwards, P. R., and Ewing, W. H. 1972. Identification of Enterobacteriaceae, Third Edition. Burgess Publishing Co. Minneapolis, MN. 362 pp.
Contributed by
From the Culture Media for Plant Pathogenic Fungi and Bacteria, University of Massachusetts: Contributed by Robert L. Wick
