MORPHOLOGICAL, PHYSICOCHEMICAL AND BIOLOGICAL VARIATIONS IN VIBRIO-ANGUILLARUM CULTURED AT LOW OSMOLARITY

The Authors studied the morphological, biochemical, physico-chemical a nd biological characteristics of Vibvio anguillarum cultured on differ ent growth conditions, characterized by low osmolarity and high temper ature (37 degrees). One culture was subcultured for several days in tr yptone soya agar with 0.5% Nacl at 37 degrees C incubation until the c ell morphology was stabilized. The low osmolarity, through an osmotic shock, induced remarkable morphological modifications in the strain, e videnced by optic and electron microscopic studied; in addition SDS-PA GE analysis of saline extracts from the culture at 37 degrees C showed a specific new protein band of about 66KDa. This band was correlated with remarkable differences in outer membrane protein composition (OMP s) evidenced by Ag/Ab cross-reactions with rabbit hyperimmune sera aga inst the modified and the reference V. anguillarum strains. Finally, t he modified strain proved to be non pathogenic for trout and sea bass.