Arbutin hydrolysis (B-Glucosidase)
From Bugwoodwiki
Purpose
Used to identify strains of Pseudomonas syringae. The test detects the presence of the enzyme, β-glucosidase, which is present in some strains of P. syringae and which splits the glucoside, arbutin.
Ingredients
| Ingredient | 1 L | 500 ml |
|---|---|---|
| Distilled water | 1000 ml | 500 ml |
| Arbutin | 5 g | 2.5 g |
| Peptone | 10 g | 5 g |
| Yeast extract | 3 g | 1.5 g |
| D-Glucose | 1 g | 0.5 g |
| Ferric citrate | 0.5 g | 0.25 g |
| Noble (purified) agar | 12 g | 6 g |
Instructions
- Add the solids to the water, adjust the pH to approximately 7.0, and autoclave.
- Plates of the medium are spotted with no more than two well separated strains and incubated at 25 28C for up to 10 days.
- A positive result is indicated by growth and browning of the medium. Care must be used in reading the results when more than one strain is cultured on a plate as often strong positive results can obscure weak positive results.
Notes
Arbutin and salicin are glucosides. The enzyme splits glucosides in such a manner that the sugar residue cannot be used for growth. Strains which utilize one of these glucosides for growth are using the aglycone portion.
References
Schaad, N. W., Jones, J. B. and Chun, W. 2001. Laboratory guide for the identification of plant pathogenic bacteria, 3rd edition. The American Phytopathological Society, St. Paul, MN. 373pp.
Contributed by
From the Culture Media for Plant Pathogenic Fungi and Bacteria, University of Massachusetts: Contributed by Robert L. Wick
