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Cloning, extracellular expression and characterization of a predominant β-CGTase from Bacillus sp. G1 in E. coli

Ong, Rui Min and Goh, Kian Mau and Mahadi, Nor Muhammad and Hassan, Osman and Rahman, Raja Noor Zaliha Raja Abdul and Illias, Rosli Md. (2008) Cloning, extracellular expression and characterization of a predominant β-CGTase from Bacillus sp. G1 in E. coli. Journal of Industrial Microbiology and Biotechnology, 35 (12). pp. 1705-1714. ISSN 1367-5435 (Print) 1476-5535 (Online)

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Official URL: http://dx.doi.org/10.1007/s10295-008-0462-2

Abstract

The cyclodextrin glucanotransferase (CGTase, EC 2.4.1.19) gene from Bacillus sp. G1 was successfully isolated and cloned into Escherichia coli. Analysis of the nucleotide sequence revealed the presence of an open reading frame of 2,109 bp and encoded a 674 amino acid protein. Purified CGTase exhibited a molecular weight of 75 kDa and had optimum activity at pH 6 and 60°C. Heterologous recombinant protein expression in E. coli is commonly problematic causing intracellular localization and formation of inactive inclusion bodies. This paper shows that the majority of CGTase was secreted into the medium due to the signal peptide of Bacillus sp. G1 that also works well in E. coli, leading to easier purification steps. When reacted with starch, CGTase G1 produced 90% β-cyclodextrin (CD) and 10% γ-CD. This enzyme also preferred the economical tapioca starch as a substrate, based on kinetics studies. Therefore, CGTase G1 could potentially serve as an industrial enzyme for the production of β-CD.

Item Type:Article
Uncontrolled Keywords:Bacillus sp. G1, cyclodextrin, cyclodextrin glucanotransferase, extracellular expression, predominant β, CGTase, signal peptide
Subjects:T Technology > TP Chemical technology
Divisions:Chemical and Natural Resources Engineering
ID Code:7263
Deposited By: Maznira Sylvia Azra Mansor
Deposited On:01 Jan 2009 04:28
Last Modified:22 Oct 2017 08:51

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