Behnam Farjami - Department of Fisheries, Faculty of Natural Resources, University of Tehran, Karaj, Iran.
Mohammad Ali Nematollahi - Department of Fisheries, Faculty of Natural Resources, University of Tehran, Karaj, Iran.
Yazdan Moradi - Iranian Fisheries Research Institute, Tehran, Iran.
GholamReza Irajian - Faculty of Medicine, Iran University of Medical Sciences, Tehran, Iran.
Melika Nazemi - Iranian Fisheries Research Institute, Tehran, Iran.
Abdollah Ardebili - Department of microbiology, Faculty of medicine, Golestan University of medical science, Gorgan, Iran.
Abazar Pournajaf - Faculty of Medicine, Iran University of Medical Sciences, Tehran, Iran.

Aquatics are a source of bioactive compounds that these compounds have different properties such as antimicrobial activity. In this study, antibacterial activity of methanol, chloroform and hexane extracts from body wall, gonad and intestine of sea cucumber Holothuria leucospilota was evaluated against Bacillus subtilis, Pseudomonas aeruginosa and Staphylococcus aureus. Bioactive compounds of body wall, gonad and intestine of the sea cucumber Holothuria leucospilota collected from the north coast of the Persian Gulf were extracted using methanol, chloroform and hexane. The antibacterial activity was determined using the serial dilution method. The minimum inhibitory concentration and minimum bactericidal concentration was evaluated by broth micro dilution method. Results demonstrated that the P.aeruginosa was shown to be the most sensitive microorganism. All concentrations of methanol extracts from body wall, gonad and intestine did not show antibacterial activity against B.subtilis and S.aureus. Methanol extracts of gonad and intestine and chloroform extract from body wall showed no antibacterial activity against P. aeruginosa. Hexane extract from gonad had no inhibitory effect on the growth of B. subtilis in any of the concentrations. Other extracts had antibacterial effect in certain concentrations studied. None of the extracts showed any bactericidal effect against B. subtilis. Based on findings of this study, sea cucumber extracts can be considered as a natural antibiotic in the future research.

antibacterial activity, bioactive compound, sea cucumber