PRODUCTION OF ANTIBIOTICS BY SOME EGYPTIAN SOIL STREPTOMYCETES

Abstract

The occurrence of extensive antibiotics resistant bacteria increased the demands for getting out new sources of antimicrobial agents. Streptomyces's, have get considerable attention worldwide due to production of many useful bioactive metabolites. In the present study Different strains of streptomycetes will be isolated from various local soil types collected from different locations in Giza and Sharkia Governorate .Primary and secondary screening were performed against Bacillus cereus, Staphylococcus aureus ,methicillin-resistant Staphylococcus aureus, Salmonella typhimurium and E. coli O157. Active isolates were selected for further studies such as antimicrobial and antitumor. Microbial strains were identified on the basis of 16SrRNA sequence. Also, GC-MS analysis of most active Actinomycetes (AC14) extracted fraction secondary active metabolites was studied. The obtained results can be summarized as The Following: 1- A total of 37 Streptomyces's were isolated from agricultural soil rhizosphere samples in Egypt. 2- All isolates were characterized based on colony morphology, mycelium coloration, and pigment diffusion 3-. The isolates were screened for their capabilities to show antimicrobial activities against different indicator pathogens, and only 18 isolates have shown significant antimicrobial activities against at least one of the tested indicator bacterial pathogens. 4-The isolate AC2 showed the same antibacterial activity against Bacillus cereus and methicillin resistance Staphylococcus aureus with inhibition zone 11 cm and showed the highest antibacterial activity against Staphylococcus aureus and salmonella with inhibition zone 14 and 15 cm, respectively