CHARACTERIZATION OF BACTERIA ISOLATED FROM PENAEUS MONODON DIGESTIVE TRACT WITH CYTOTOXIC EVALUATION

A gram negative, motile, lactose fermenting, Pseudomonas aeruginosa was isolated from the dissected digestive tract of Penaeus monodon by plating the sample onto an agar solidified LB medium. The optimum growth of the bacteria was observed at pH 7.5 and at temperature 300C. Cytotoxic effect of bacteria and bacteriocin was tested on Artemia salina through LC50 to evaluate whether they have any beneficial effect or not. LC50 for bacteria was 205.9645 ?l (O.D.=600) and the regression equation was Y = -1.064911 + 2.621199 X, while the 95% confidence limits are 143.3878 to 295.8508 ?l for 12h exposure. Whereas for bacteriocin LC50 was 65.65591 ?l and the regression equation was Y = 2.166407 + 1.559255 X, while the 95% confidence limits are 25.40323 to 69.691 ?l for 6h exposure only. So, the bacteriocin has adverse effect on Artemia salina and the bacteria showed resistant against Gentamycin, Ceftazidime and Nalidixic acid and the MIC value was 12.5 ?g/ml against Gentamycin.