افزايش توليد آنتي‌بيوتيك تايلوزين در باكتري Streptomycess fradiae با استفاده از روش موتاسيون

Enhancement of tylosin production in Streptomyces fradiae by Mutation

در اين بررسي از دو موتاژن اشعه uv با طول موج nm 280 و (EMS (Ethylmethanesulfonate با غلظت‌هاي متفاوت براي ايجاد موتاسيون و افزايش توليد تايلوزين در باكتري Streptomycess fradiae استفاده شد. منحني مرگ براي هر دو موتاژن رسم گرديد و شرايط بهينه براي ايجاد موتاسيون توسط اشعه uvبا فاصله 20 سانتي‌متري و مدت زمان 40 تا 60 ثانيه و براي EMS مدت زمان 30 دقيقه و غلظت (w/v) 4 درصد تشخيص داده شد. در مرحله اول، موتاسيون با uv انجام شد و سويه‌هاي داراي توليد بالا به روش پلاك آگار ارزيابي شدند. در غربال‌گري ثانويه سويه 24U با توليد mg/ml 892/0 تايلوزين و 28/1 برابر بيشتر از سويه وحشي به عنوان سويه مناسب انتخاب شد و در مرحله دوم تحت تيمار با EMS قرار گرفت. در نهايت سويه موتانتي با توليد mg/ml 18/2 تايلوزين و 12/3 برابر افزايش توليد نسبت به سويه وحشي بدست آمد.

In order to increase tylosin production by Streptomyces fradiae, two mutagens, i. e. uv and EMS (Ethylmethanesulfonate) were used. Death curves were plotted for these mutagens. Optimum condition for obtaining mutants by uv radiation was determined by using a uv source lamp at a distance of 20 cm for 40-60 seconds. When EMS was used at 4% (w/v) concentration, the best mutants were isolated after 30 minutes of exposure to the mutagen. In the first mutation step, which was done by uv radiation, high tylosin producing strains were isolated by Plaque Agar method as the first screening step. For the second step of screening, a mutant strain (U24) with a production of 0.892 mg tylosin per ml was isolated, which was 1.27 times more productive than the wild type. The secondary mutation step on this mutant strain was performed by EMS. Finally, a mutant strain (UE1) with a production of 2.18 mg tylosin per ml was obtained, which was 3.12 times more productive than the wild type.