CHARECTERIZATION OF ENTEROTOXIN PRODUCED BY LOCAL ISOLATE OF YERSINIA ENTEROCOLITICA an‎d STUDY OF THE INHIBITORY EFFECT OF ERUCA SATIVA ON ITS ACTIVITY

Enterotoxin produced by local isolate of Yersinia enterocolitica was purified from the culture supernatant .The purification procedure involved precipitation by ammonium sulfate (50% saturation ) and analyzed by sodium dodecyl sulfate- poly acrylamide gel electrophoresis (SDS-PAGE), ( 159.4) fold purification was achieved with yield of (17.9)%. The molecular weight of purified enterotoxin was 11,000 Dalton. The purified enterotoxin was heat stable at 100 оC for 15 min, and the activity was lost after incubation with 3mM dithiotheritol as reducing agent. Enterotoxic activity of Y. enterocolitica was neutralized by antiserum from mice immunized with the purified enterotoxin .The inhibitory activity of Eruca sativa extracts was tested, both seed and leave extracts had inhibitory activity in a dose- dependent manner.