Gelatin liquefaction
From Bugwoodwiki
Purpose
Used for differentiating species in the non-soft rot group of Erwinia. Diagnostic for E. amylovora, E. herbicola pv. herbicola, E. herbicola pv. milletiae, E. anannas, and E. uredovora.
Ingredients
| Ingredient | 500 ml | 250 ml |
|---|---|---|
| Distilled water | 500 ml | 250 ml |
| Beef extract | 1.5 g | 0.75 g |
| Peptone | 2.5 g | 1.25 g |
| Gelatin | 60 g | 30 g |
Instructions
- Dissolve ingredients and dispense in 4-6 ml amounts in tubes. Autoclave and keep cool until inoculated.
- Stab-inoculate medium with 24-hr cultures. Incubate at 20-22 °C. After 3, 7, 14, and 21 days, place tubes at 4 °C for 30 min. prior to recording the results. If the medium flows readily as tube is gently tipped, the gelatin has been hydrolyzed and denotes a positive reaction for the test. The test is considered doubtful if a very slow flow of the medium occurs. Compare results with noninoculated medium incubated and cooled as above.
Notes
- The medium should be relatively fresh when used.
References
- Schaad, N. W. 1988. Laboratory Guide for the Identification of Plant Pathogenic Bacteria (2nd ed.). The American Phytopathological Society: St. Paul, MN. 164 pp. (p. 50)
Contributed by
From the Culture Media for Plant Pathogenic Fungi and Bacteria, University of Massachusetts: Contributed by Robert L. Wick
