Hydrogen sulfide production
From Bugwoodwiki
Purpose
Useful for distinguishing between Erwinia and Xanthomonas. Many species of Erwinia will produce H2S from cysteine.
Ingredients
| Ingredient | 500 ml | 250 ml |
|---|---|---|
| Distilled water | 500 ml | 250 ml |
| NH4H2PO4 | 0.25 g | 0.125 g |
| K2HPO4 | 0.25 g | 0.125 g |
| MgSO4 • 7H2O | 0.1 g | 0.05 g |
| NaCl | 2.5 g | 1.25 g |
| Yeast extract | 2.5 g | 1.25 g |
| Cysteine hydrochloride | 0.05 g | 0.025 g |
Instructions
- Dispense in 5 ml lots and autoclave.
- After inoculation, suspend a lead acetate strip over the medium; hold in place by cap. Examine up to 14 days afterwards for blackening of the lead acetate strip, which indicates hydrogen sulfide release from cysteine.
Notes
- Hydrogen sulfide is released from cysteine.
References
- Fahy, P. C. & Persley, G. J. 1983. Plant Bacterial Diseases, A Diagnostic Guide. Academic Press, NY. 393 pp. (p. 357)
Contributed by
From the Culture Media for Plant Pathogenic Fungi and Bacteria, University of Massachusetts: Contributed by Robert L. Wick
