محمد مدرسی

introduction: Cyanobacteria produce intra and extra cellular metabolite as biocontrol agents bacteria. The objective of this study was to investigate cyanobacteria. Phormidum sp. antibacterial characteristics versus pathogenic bacteria (klebsiella pneumoniae ). method: the antibacterial activity of cyanobacteria species for Phormidium sp at levels30, 50, 100, 150 ?l were studied using Antibacterial examination included well diffusion method. The methanolic extract was obtained with a 24-hour exposure of methanol and were used for antagonistic activity against klebsiella pneumoniae Result: the Result of the antibacterial examination showed growth inhibition zone versus klebsiella pneumoniae for concentration 30, 50, 100 and 150?l but didn’t show growth inhibition zone for 30?l .