Antimicrobial activity of agent produced by Streptomyces spp.isolated from soil samples

Abstract

Twenty two soil samples were collected from Hilla City. Twelve isolates of Actinomycetes were found. Eight isolates of Streptomyces spp. was detected according to morphological test on yeast malt extract agar. Theses isolates are positive for gram stain and having grey aerial mycelium and yellow-brown substrate mycelium. Activity of Streptomyces spp. isolates were tested against S.aureus. Streptomyces spp.6 was given higher inhibition zones (20)mm compared with low inhibition zone by other Streptomyces spp. isolates.Streptomyces.6 was chosen for agent extraction. Streptomyces spp.6 having grey aerial mycelium and yellow-brown substrate mycelium , unable for melanin production and able to ferment glucose, mannitol, sucrose, and negative for urea and catalase test. Agent was extracted from Streptomyces spp.6.Activity of agent was examined against clinical bacterial isolates. The results showed that this agent having antimicrobial activity against clinical isolates with inhibition zone about (12- 22 mm).