رسائل ماجيستير
English
2015
Antimicrobial activity of a Number of Streptomyces species
ابتهال محمود ربيع عياد, سمير البرغوثي
كلية الدراسات العليا-جامعة القدس · فلسطين
Streptomycesa gram-positive filamentous bacteria, that is widely distributed in most soilsand decaying vegetation. Most Streptomycetesreproducebyspores anddistinct for their earthy odor that result fromtheproduction of a volatileterpene called geosminwhichis one of the most famous metabolites that are produced by this genus. The discovery of streptothricin in 1942was the starting point of history of antibiotics derived from Streptomyces, and thenthe discovery of streptomycin two years later, after which scientists intensified research’s for antibiotics within the genus. Today, a large number ofantibiotics are produced bythe genus Streptomyces, producing antibacterial, antifungal, and antiparasitic drugs, and also a large numberof other bioactive compounds, such as immunosuppressants. It is thought that the productions of the bioactive compounds produced by Streptomyces areinitiated during the time coinciding with the aerial hyphal formation from the substrate mycelium. Streptomycinand oleandomycinare examples of antimicrobial compounds against tuberculosisthat are produced by Streptomycesgriseus and Streptomyces antibioticusrespectively. FK506an immunosuppressant is another bioactive compound that is produced by Streptomyces tsukubaensis, while avermectin, bleomycin, and daunomycinare antitumor compoundsthat are produced by StreptomycesavermitilisStreptomyces verticillusandStreptomyces peuceticusrespectively.In this research, Streptomycespratensis QUBC97 was isolated on CCG medium and identified by molecular methods. The isolate produced an antibacterial agent when grown in CCG broth that showed tow distinguishable compounds from fresh or old cultures. The freshly produced compound was extracted in n-butanol and showed an Rfvalue of 0.86 when developed on silica gel TLC plates in n-butanol saturated with 1.7% ammonium acetate. The compound absorbed visible light at 426 and 440 nm. Putative identification of HPLC purified and concentrated compound using mass spectroscopy suggested the compound to be methoxy, 1-phenyl-, oxime. This work is a step in the direction of developing our capacity in detection, isolation, and industrialization of antimicrobial agents.