Production and Characterisation of Cyclodextrin Glycosyltransferase from a Locally Isolated Bacillus Sp

Ai Noi, Sauvaphap (2006) Production and Characterisation of Cyclodextrin Glycosyltransferase from a Locally Isolated Bacillus Sp. Masters thesis, Universiti Putra Malaysia.

[img] PDF
413Kb

Abstract

Cyclodextrin glycosyltransferase (E.C.2.4.1.19) synthesise cyclic oligosaccharide which is also known as cyclodextrin, from starch. Most of the known CGTases produce a mixture of a-, B- and Y-CD at different ratios. CGTase producing microorganism was isolated from local soils on selective agar medium containing soluble starch which produced clear zones as qualitative measurement of the enzyme present. A total of 250 isolates were collected but only one isolate (Strain MK 6) was selected for further studies based on its highest activity. Strain MK 6 was identified as gram positive rod, motile and produced spore. Biochemical identification using API CHB/E medium confirmed the strain MK 6 was the Bacilllus sp with 85% similarities. CGTase isolated from alkalophilic Bacillus sp. was further characterized. Optimum activity obtained at temperature of 70oC and the enzyme shows a wide range of pH stability ranging from 4 -10 when stored at 4oC for 24 hours and temperature stability ranging from 30oC - 80oC at 1 h incubation period. The CGTase activity was even maintained at 0.4 U/ml at 90oC for 40 min incubation. Prior to optimisation of CGTase production, selection for the best carbon source through detection on modified phenolphthalein method containing different types of starch were performed. Sago starch gave significant result and was used for further optimisation using statistical analysis namely Response Surface Methodology (RSM). The optimal calculated values were 3.34% sago starch, initial pH of 10.15 and agitation speed of 187 rpm; with predicted activity of 2.07 U/ml of CGTase. These predicted optimal parameters were confirmed in the laboratory and the final CGTase activity obtained was very close to the predicted value at 2.56 U/ml. The optimised crude enzyme produced mainly y-CD (61.6% of the total cyclodextrin amount) with only y-CD as minimal product without detection of y-CD.

Item Type:Thesis (Masters)
Subject:Cyclodextrins
Subject:Glycosyltransferases
Chairman Supervisor:Professor Madya Suraini Abd. Aziz, PhD
Call Number:FBSB 2006 35
Faculty or Institute:Faculty of Biotechnology and Biomolecular Sciences
ID Code:4843
Deposited By: Nurul Hayatie Hashim
Deposited On:31 Mar 2010 10:24
Last Modified:27 May 2013 07:18

Repository Staff Only: item control page

Document Download Statistics

This item has been downloaded for since 31 Mar 2010 10:24.

View statistics for "Production and Characterisation of Cyclodextrin Glycosyltransferase from a Locally Isolated Bacillus Sp"


Universiti Putra Malaysia Institutional Repository

Universiti Putra Malaysia Institutional Repository is an on-line digital archive that serves as a central collection and storage of scientific information and research at the Universiti Putra Malaysia.

Currently, the collections deposited in the IR consists of Master and PhD theses, Master and PhD Project Report, Journal Articles, Journal Bulletins, Conference Papers, UPM News, Newspaper Cuttings, Patents and Inaugural Lectures.

As the policy of the university does not permit users to view thesis in full text, access is only given to the first 24 pages only.