Potato rhizosphere soil and tuber samples were collected from Hamadan, Esfahan, Ardabil and Tehran provinces. A total of 170 strains of fluorescent pseudomonas were isolated using Pseudomonas agar F medium. By comparasion of total protein pattern 28 representatives were selected, and their phenotypic features as well as ability to produce antibiotic and siderophore were evaluated. Tested strains were positive for gelatin, arginine dihydrolase, oxidase, lecithinase and growth at 4?C but for HR reaction on tobacco leaf, production of non fluorescent pigment, levan and potato rot performed negatively. Most of the tested strains were capable of reduction of nitrate to nitrite as well as growth at 41?C. Tested strains could use different carbon sources including L–arabinose, D-xylose, D-galactose, sucrose, D-alanine, L-tartrate acid but did not use propionate, adonitol, ethanol, geraniol. A few strains were positive for sorbitol, trehalose, M-inositol, butyrate, valerate, phenylacetate, nicotinate and butylamine consumption. Based on the characterized features, tested strains mainly belonged to P. fluorescens Biovars III, IV and V with biovar III being predominant. The isolates produced antibiotic and siderophore in in vitro conditions.
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