study of biological activity of four strains of pv. and identification of their bioactive metabolites using GC-MS.

This research was carried out to study antibacterial activity of 4 strains of pv. () against G+ve and G-ve , haemolytic activity against the cell membrane of erythrocytes, the production of extracellular hydrolytic enzymes and finally, the pathogenicity against flesh blocks. Chemical structure of bioactive substances of the most bioactive strain (ICMP 11096) was established using gas chromatography-mass spectrometry (GC-MS). All the studied strains inhibited the growth of the two tested bacteria although some growing substrates negatively influenced the antimicrobial substance production. The same strains showed highly haemolytic activity and were able to produce 3 hydrolytic enzymes, i.e. chitinase, glucanase and protease. In pathogenicity assays, the considered strains resulted virulent for . . The GC-MS for compounds from ICMP 11096 were compatible with the structure of two bioactive fatty acids identified as methyl stearate and ethanol 2-butoxy phosphate with mass spectrum m/e 298 and 398, respectively.