Mansour Amin - Health Research Institute, Infectious and Tropical Diseases Research Center, Department of Microbiology,School of Medicine, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran
Zeinab Rakhisi - Islamic Azad University Fars Science and Research Branc, Fars, Iran
Amanollah Zarei Ahmady - Nanotechnology Research Center, Faculty of pharmacy, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran

Bacillus species being the predominant soil bacteria because of their resistant endospore formation and production of essential antibiotic like bacitracin. The aim of this study was to isolation of Bacillus Spp. from riverside soil and investigation of antimicrobial characteristics against some pathogenic bacteria. Fifty soil samples were collected from different sites of Bahmanshir riverside in Abadan city, and analysed for the presence of Bacillus species. The media used in this research was nutrient broth and agar. The Bacillus species were identified by their phenotypic and biochemical characteristics. The antimicrobial effect of Bacillus extracts against the target bacteria including Escherichia coli, Staphylococcus aureus, Salmonella typhi, Shigella dysenteriae and Corynebacterium diphtheriae was examined. The identified Bacillus species were included: B. cereus (86.6%), B. subtilis(6.6%), B. thuringiensis (3.3%) and B. pumilus (3.3%). The evaluation of theantimicrobial activity of extracted compounds was carried out against 5 bacteria. Antibiotic production tests indicated that two Bacillus strains belong to B. cereus showed antimicrobial properties. The MIC values of these compounds were ranged between 8.34 - 33.34 mg/ml for target bacteria. This study indicated that some Bacillus species have potential to produce antimicrobial compounds that can be use to control microbial infections.

Soil bacteria, antimicrobial, Bacillus species