The need for new antibiotics has become increasing apparent in the last years with the rise of antibiotic resistant bacteria. The aim of this study is to isolate the bacteria from digestive system of Iran endemic slug, which produce antimicrobial components and antimicrobial effects.
Sampling was done from slug’s digestive system and all bacteria were isolated by nutrient agar according to their colonies morphology and colors. Identification of bacteria was done with phylogeny method and standard biochemical tests. To detect antimicrobial activity, agar diffusion tests with standard test organisms. Sterile antibiotic assay disks were soaked with supernatant of culture broth of the strains and put on plates with standard test organisms and checked afterwards for inhibition zones. For extraction of antimicrobial component, chloroform, n-hexan and ethyl acetate used as solvent that were mixed with supernatant and antimicrobial test was done from these solvents and watery phases.
Four bacteria were isolated that the best bacterium of them was selected to more studying. This bacterium is an obligate aerobic, Gram negative, coccubasil-shaped, catalase-positive, oxidase-positive producing green-blue pigment. The mentioned bacterium seems to have an affinity with standard test organisms. Analyses were showed the antimicrobial product is nonpolar.
Due to high antimicrobial effects of this bacterium as well as increscent need to new antibiotics, purification and identification of this antimicrobial component  seem to be necessary for introducing of new medicinal source.
Keywords: slug, antimicrobial component, disk diffusion