Selective isolation of fluorescent and nonfluorescent Pseudomonas species from Sohag Governorate (Upper Egypt).

Three hundred and fourty nine isolates belonging to ten different species of Pseudomonas were isolated and identified from soil and water samples on four selective isolation media: Modified Trypticase soy agar (TSA), ACC-agar containing ampicillin-chloramphenicol-cycloheximide, Nitrate plus organic acid agar and Tryptophan substrate agar. The fluorescent species were P. putida (21.2% of the total Pseudomonas species), P. fluorescens (15.8%), P. aeruginosa (9.7%) and P. aureobaciens (2.6%), while the nonfluorescent species were P. stutzeri (12.4%), P. alcaligenes (11.2%), P. pseudoalcaligenes (9.5%), P. mendocina (8.3%), P. lemoignei (5.7%) and P. ruhlandii (3.4%). Modified TSA and ACC media were efficient for the isolation of both fluorescent and nonfluorescent species, whereas Nitrate and Tryptophan media were more selective for the isolation of nonfluorescent species. The optimum temperature for the isolation of different species ranged between 20 degrees and 37 degrees C.