King's medium B
(Redirected from Kings Medium B)
For distinguishing fluorescent pseudomonads from nonfluorescent pseudomonads
|Ingredient||1 L||500 ml|
|Distilled water||1 L||500 ml|
|proteose peptone #3 (Difco)||20 g||10 g|
|K2HPO4||1.5 g||0.75 g|
|MgSO4•7H2O||1.5 g||0.75 g|
|glycerol||10 mL||5 ml|
|agar||15 g||7.5 g|
- Mix water and peptone first
- Bring it to a boil and dissolve
- Add other chemicals
- Heat until all dissolve.
- This medium is the best general isolation medium for bacteria. Fluorescent pseudomonads produce a yellow pigment that fluoresces under longwave ultraviolet light (366 nm). Some isolates from the P. syringae group don’t fluoresce.
- This medium may not be suitable for longer term (more than 2 days) storage of Erwinia because some may die on it within a few days to a week.
- It is important to use proteose peptone #3 and not other peptones in order to allow colonies to produce fluorescent pigments.
- This mix is also commercially available as Difco Pseudomonas agar F.
- Schaad, N. W. 1980. Laboratory Guide for the Identification of Plant Pathogenic Bacteria. The American Phytopathological Society, St. Paul, MN. 72 pp. (p. 3)
From the Virginia Tech Mediabook; Orignially created by Robert Wick; contributed by Mary Ann Hansen