Phylum Proteobacteria, Class Gammaproteobacteria, Order Pseudomonadales, Family Pseudomonadaceae, Genus Pseudomonas,
Pseudomonas agarici Young 1970.
Gram-negative rods, motile by one, rarely two, polar flagella.
Circular, 2 mm in diameter, domed, whitish, with a buttery consistency colonies.Aerobic, optimum growth temperature 26 ºC.
Media: Nutrient agar, Nutrient broth, King's B medium.
Isolated from soil & comestible mushrooms (Agaricus bisporus).
Causes “Drippy gill” of mushroom (cream-grey droplets that develop on the gills) or superficial brown discolorations on the caps and
stalks of deformed sporophores.
- Young J.M.: Drippy gill: a bacterial disease of cultivated mushrooms caused by Pseudomonas agarici n. sp. New Zealand
Journal of Agricultural Research, 1970, 13, 977-990.
- George M. Garrity, Julia A. Bell & Timothy Lilburn: Order IX Pseudomonadales Orla-Jensen 1921 In: Bergey’s Manual of
Systematic Bacteriology, Second edition,Vol two, part B, George M. Garrity (Editor-in-Chief), 2005, pp. 323-442.
- Pietro Lo Cantore & Nicola S. Iacobellis: First report of brown discoloration of Agaricus bisporus caused by Pseudomonas
agarici in southern Italy. Phytopathol. Mediterr. (2004) 43, 35–38.
Green, fluorescent pigment produced (weak fluorescence).
Acid is produced from arabinose, glucose, mannitol, fructose, galactose & ribose.
Acetate, benzoate, citrate, formate, fumarate, gluconate, lactate, propionate, succinate
& beta-alanine are utilized. Oxidase & catalase positive.
Acid is not produced from rhamnose, xylose, mannose, lactose, sucrose, maltose,
dextrin, glycogen, inositol, sorbitol, adonitol & salicin. Galacturonate, oxalate, tartrate,
trehalose, 2-ketogluconate, meso-inositol, ethanol, histamine & nicotinate are not
utilized. Nitrates reduction, pectate liquefaction, starch hydrolysis, esculin hydrolysis,
levan production from sucrose, arginine dihydrolase & gelatin hydrolysis are negative.
L-valine utilization is variable.
(c) Costin Stoica