PHENOTYPIC CHARACTERIZATION OF PSEUDOMONAS SYRINGAE pv. TABACI, THE CAUSAL AGENT OF TOBACCO WILDFIRE

Tobacco wildfire caused by Pseudomonas syringae is a major destructive foliar bacterial disease worldwide. Phenotypic characterization of the pathogen was investigated to provide some basic information on biology and pathology by using BIOLOG Phenotype MicroArray (PM). Using PM plates 1 to 10, 950 different growth conditions were tested. Results showed that the pathogen was able to metabolize 37.89% of tested carbon sources, 13.42% of nitrogen sources, and 10.17% of phosphorus sources, whereas it metabolized none of the tested sulfur sources and presented no biosynthetic pathways. The most informative utilization patterns for carbon sources of P. syringae were carbohydrates and amino acids, and for nitrogen were only amino acids. It showed active metabolism at 3% sodium chloride, at the combination of N, N-dimethyl-glycine with 6% sodium chloride, at the combination of trigonelline with 6% sodium chloride, at 4% potassium chloride, at 3% and 5% sodium sulfate, at 15% ethylene glycol, at 1% sodium lactate, at 100 mM sodium nitrate, with up to 200 mM sodium phosphate (pH 7), and with up to 50 mM ammonium sulfate (pH 8). It exhibited active metabolism in the range of pH values between 5.5 and 6. P. syringae showed poor decarboxylase activity, whereas no deaminase activity in the presence of various amino acids was noted.