Production of α-amylase by locally isolated strains of bacillus subtillus

العناوين الأخرى

إنتاج ألفا أميليز من قبل سلالات معزولة محليا من بكتريا Bacillus subtilis

مقدم أطروحة جامعية

Rustum, Bakhan Muhammad

مشرف أطروحة جامعية

Qujah, Abd al-Jabbar Umar

أعضاء اللجنة

Thlij, Karkaz Muhammad
Mahmud, Walid Ahmad
Nasib, Zaynab Muhammad

الجامعة

جامعة صلاح الدين

الكلية

كلية الزراعة

دولة الجامعة

العراق

الدرجة العلمية

ماجستير

تاريخ الدرجة العلمية

2010

الملخص الإنجليزي

-This study was carries out in the laboratory of Food technology department, College of Agriculture, University of Salahaddin-Erbil, at period 1st November 2008 to 1st October 2009, it was conducted to isolate and identification of Bacillus subtillus from soil samples takes at Erbil and Sulaimanyah cities.

The results were illustrated that one hundred and twenty two strains of bacteria were collected.

The isolates were inculated in culture medium contains 1% starch for determining there abilities of amylase production, starch hydrolyzing enzyme by making a clear zone around the bacterial colony.

According to the morphology and to biochemical reactions, 104 isolated of these bacteria have been characterized.

The ability of isolated strains for producing amylase enzyme were tested.

The enzyme production conditions which included the culture medium composition, incubation temperature, pH, agitation and incubation period were studied.

The best ten isolates having the maximum ability to produce amylase enzyme ranged between (169.33-115.62) enzyme unit/min for the strains (ST52 and ST63) respectively before optimization.

After optimization the enzyme production conditions, the activity was increased 2.42 and 1.54 folds to each strain ST44 and ST42 respectively.

The optimum conditions to produce alpha amylase are: 1.

Using production medium contains 1% starch as a carbon source and 0.6% peptone was chosen as the best concentration of nitrogen source.

2.

Using 50 ml of production medium with pH 7.0 and incubation temperature at 55°C, with 150 rpm agitation for 72 hrs was chosen as the optimal operational conditions for α-amylase production.

3.

The enzyme activity increased 4.55 and 4.25 folds for each of the strains ST52 and ST7 respectively after precipitation by using 70% of saturation of ammonium sulphate and 6.24 and 5.02 folds for each of the strains ST52 and ST7 by using 1 volume of acetone, respectively.

4.

After studying the best conditions of α-amylase enzyme production, the activity reached maximum in both exponential (log) and stationary phase.

5.

The enzyme retained 100% of its activity at 70°C.

6.

Michaelis-Menton proven reached the value 0.55 mili molar after precipitation

التخصصات الرئيسية

الأحياء

الموضوعات

• التكنولوجيا الحيوية
• الأميلاز

عدد الصفحات

92

قائمة المحتويات

• APA
• MLA
• AMA

لغة النص

الإنجليزية

نوع البيانات

رسائل جامعية

رقم السجل

BIM-311086