Phylum Proteobacteria, Class Gammaproteobacteria, Order Pseudomonadales, Family Pseudomonadaceae, Genus Pseudomonas,
Pseudomonas rhizosphaerae Peix et al. 2003.
Gram-negative, nonspore-forming, rodshaped cells, 1.2-2.4 μm in length and 0.8-0.9
μm in diameter. Motile by one polar flagellum.
Colonies on YED agar are circular, convex, yellow, weakly translucent and usually 1-2
mm in diameter after 2 days growth at 28 ºC. No fluorescent pigments produced.
Produce a yellow pigment in media that contain glucose as the carbon source and
form a transparent ‘halo’ around colonies in media that contained insoluble bicalcium
phosphate as the phosphorus source.
Strictly aerobic, growth temperature 22-28 ºC (optimal 25 ºC). Can grow at 4 ºC but not
at 41 ºC. Other media: Nutrient agar.
Isolated from the rhizospheric soil of grasses in Spain.
- Peix, Alvaro, Rivas, Raul, Mateos, Pedro F., Martinez-Molina, Eustoquio, Rodriguez-Barrueco, Claudino, Velazquez, Encarna.
Pseudomonas rhizosphaerae sp. nov., a novel species that actively solubilizes phosphate in vitro. Int J Syst Evol Microbiol 2003
Positive for catalase, utilization as sole carbon source of: L-arabinose, D-arabinose, D-xylose, ribose, mannose, galactose, D-
fructose, L-sorbose, D-fucose, L-fucose, rhamnose, dulcitol, inositol, sorbitol, mannitol, adonitol, glycerol, erythritol, D-arabitol,
gentiobiose, D-turanose, D-tagatose, glucose, caprate, malate, gluconate, 2-ketogluconate, 5-ketogluconate & citrate.
Negative for arginine dehydrolase, caseinase, gelatinase, beta-galactosidase, indole production, H2S production, esculin hydrolysis,
oxidase, starch hydrolysis, tryptophan deaminase, urease, acid production from glucose, utilization of: N-acetylglucosamine, maltose,
adipate & phenylacetate.
(c) Costin Stoica