Document Details

Document Type : Thesis 
Document Title :
Production of β-galactosidase by immobilized lactic acid bacteria
إنتاج إنزيم البيتا جالاكتوسيد يز بواسطة بكتريا حمض اللاكتيك
 
Subject : biological sciences department 
Document Language : Arabic 
Abstract : The β-galactosidase enzyme can be obtained from microorganisms, plants, and animals. The use of β-galactosidase for the hydrolysis of lactose in milk and whey is one of the promising enzymatic applications in food and dairy processing industries. The enzyme can be used in either soluble or immobilized forms. Immobilization has been found to be convenient method to make enzyme thermo stable and to prevent the loss of enzyme activity. Twenty Lactic acid bacterial isolates were obtained from dairy product samples which were collected from Jeddah, Saudi Arabia. All the bacterial isolates were screened for the presence of β-galactosidase on MRS agar medium. Only seven bacterial isolates showed green colons on MRS (Mann, Rogosa and Sharp ) agar medium containing X –gal .The amount of β-galactosidase was determined by spectrophotometry using oNPG as substrate . The highest β-galactosidase producer was the isolates KH2. A homogenization method was used for the release of β-galactosidase from lactic acid bacterial cells. For characterization of the most active isolate, it was examined with light and scanning electron microscope. Cell and culture morphology in addition to physiological characters and biochemical tests were studied. It was identified as an isolate belonging to lactobacillus acidophilus RK. Immobilization was used to enhance enzyme activity. The isolate Lactobacillus sp. was immobilized on calcium alginate beads intra-cellular and extra- cellular enzyme were determined and compared in immobilized and non-immobilized cells. Concerning the immobilized cells, both the intra-cellular and extra cellular enzymes production has higher activity compared to non immobilized cells enzyme. The effects of different factors on the enzyme production were studied. After immobilization, the maximums production was at 40oC (optimum temperature) and at initial pH at 4.8. The enzyme was precipitated using 80% of ammonium sulphate and purified using Sephadox G-100 column. The optimum temperature of pure enzyme activities was at 35oC and pH was at 6.2. The molecular weight of the enzyme was 112 kDa as shown by SDS -PAGE analysis 
Supervisor : Prof. Dr. Reda Fouad Allam Radi 
Thesis Type : Master Thesis 
Publishing Year : 1435 AH
2014 AD 
Added Date : Wednesday, July 2, 2014 

Researchers

Researcher Name (Arabic)Researcher Name (English)Researcher TypeDr GradeEmail
خضراء مساعد الزهرانيAl-Zahrani, Khadra MusaedResearcherMaster 

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