Impact of Lactic acid bacteria (LAB) as probiotic against bacterial pathogen from Cyprinus carpio L

The aim of the present study is to investigate the potential of lactic acid bacteria as a probiotic (biologicl dieases control). Six strains of lactic acid bacteria J1, J3, J4, J6, J7, J8 was Isolated from intestines of the common carp Cyprinus carpio were compared as to the antagonistic activity against fish pathogen bacteria Aeromonas hydrophila, Pseudomonas luteola Pseudomonas aeroginosa Sarratia rabidaeae and staph sp. Different method were used for measuring growth by optical density, agar well diffusion and cross- streak method also screened from bile salt and antibiotic tolerance. All strains of LAB showed different spectra of inhibition against pathogenic bacteria. The highest inhibition measured against serratia rubidaeae and A. hydrophila, moderate inhibition occure against. P. luteola and P aeroginosa and lower inhibition to staph sp. Also culture supernatant free fluid of all LAB showed no antagonistic activity against pathogenic bacteria moreover all strain show resistance to all antibiotic sensitivity OA2A–P disc except J1, J3, J4 were sensitive to erythromycin in concentrate 60 mcg after incubation for 48 hr and only J1, J3, J4, J6 were exhibited tolerance reaction to bile salt at concentration not more than 3000 ppm the present study recommend to use lactic acid bacteria J6 as a good probiotic remedy to the fish culture in Iraq.