Persistence of the antivibrio property of the potential
antagonistic probiotics, Pseudomonas MCCB 102 and
103, at di¡erent temperatures, pH and in organic solvents
was studied. The antivibrio compound was extracted,
puri¢ed and characterized using thin-layer
chromatography, high-pressure liquid chromatography,
liquid chromatography-mass spectroscopy, UV^
Vis and nuclear magnetic resonance spectroscopy
and identi¢ed as N-methyl-1-hydroxyphenazine, a
phenazine antibiotic. The toxicity of the compound
was tested in Penaeus monodon haemocyte culture
and the IC50 valuewas found to be1.4 _ 0.31mg L_1.
The compound was found to be bacteriostatic at
0.5mg L_1. Its stability to varying temperature, pH,
organic solvents, prolonged shelf-life and vibriostatic
nature point to its suitability for prophylatic aquaculture
application
