Application of transformation method in transfer of antibiotic production property from streptomyces sp. to Escherichia coli pBR322

العناوين الأخرى

تطبيق طريقة التحول الوراثي في نقل صفة إنتاج مضاد حيوي Streptomyces sp. من بكتريا Escherichia coli pBR إلى 322

مقدم أطروحة جامعية

al-Hajjaj, Murtaqab Yunus Ubayd

مشرف أطروحة جامعية

Mahdi, Kawthar H.
Abd Allah, Fawziyah A.

أعضاء اللجنة

Hassan, Talib F.
Ali, Dawud S.
al-Badran, Adnan Isa

الجامعة

جامعة البصرة

الكلية

كلية الطب البيطري

القسم الأكاديمي

قسم الأحياء المجهرية

دولة الجامعة

العراق

الدرجة العلمية

ماجستير

تاريخ الدرجة العلمية

2006

الملخص الإنجليزي

The local Streptomyces sp.

strain was subjected to cultural, microscopical and biochemical tests, which confirmed that this strain kept its characteristics prior to storage.

This strain showed an ability to produce antimicrobial metabolite active against standard strains Bacillus subtilis (PCI 219), Escherichia coli (NCTC 5933), Klebsiella pneumoniae (ATCC 10031) and Staphylococcus aureus (NCTC 6571), in primary and secondary screening.

Two modified fermentation media with the a standard one were used to obtain the highest antibiotic production, which was calculated according to the growth inhibition zones of the standard strains, the F.M.III was chosen as the best F.M.

that gave 24 mm IZD against Staph.

aureus (NCTC 6571).

Then different cultivation conditions were used to obtain the optimum antibiotic production, which was observed at 28oC, pH 6.8 and 7, NaCl concentration 4%, and shaking at 180rpm.

The produced antibiotic was extracted, purified and identified by different chemical colour tests, melting point and solubility, physical tests, IR and UV.

Spectra, which demonstrated that the antibiotic was peptide, and produced about 1.4 g/l antibiotic in F.M.III at optimum production conditions.

The biological properties: MIC showed different values, the minimum was 0.25 μg/ml against Staph.

aureus (NCTC 6571) and the maximum was 9.3 μg/ml against Pseudomonas aeruginosa (NCTC 6750).

The LD50 was 5500 mg/kg.

There was an inverse effect for orange acridine dye on the grown colonies number of S.

sp., the 28 g/ml dye concentration was chosen as the best concentration because it led to colonies killing by 95%.

Extraction of plasmid DNA solution had a positive reaction in diphenylamine, with only one band on electrophoresis.

The E.

coli pBR 322 showed negative results against the standard strains in primary screening, which means that the E.

coli pBR 322 did not have any antimicrobial effect before transformation, while transformed E.

coli pBR322 showed positive results after plasmid DNA transformation.

The antibiotic produced by trans.

E.

coli pBR322 was extracted, purified and identified by the same ways that were done for the antibiotic produced by S.

sp.

all these tests (melting point, chemical colour test, infrared and ultraviolet spectrum) and the biological properties, MIC and LD50 indicated that this antibiotic was the same antibiotic produced by S.

sp.

with an increase of 2.2 g/l in the quantity.

التخصصات الرئيسية

الطب البيطري

عدد الصفحات

124

قائمة المحتويات

• APA
• MLA
• AMA

لغة النص

الإنجليزية

نوع البيانات

رسائل جامعية

رقم السجل

BIM-755931