Effects of substrates and reaction conditions on production of cyclodextrins using cyclodextrin glucanotransferase from newly isolated Bacillus agaradhaerens KSU-A11
Full Text
Reprint PDF

Keywords

Bacillus agaradhaerens
cyclodextrin glucanotransferase
cyclodextrinc
enzymatic reaction
starch

How to Cite

1.
Ibrahim AS, El-Tayeb MA, Elbadawi YB, Al-Salamah AA. Effects of substrates and reaction conditions on production of cyclodextrins using cyclodextrin glucanotransferase from newly isolated Bacillus agaradhaerens KSU-A11. Electron. J. Biotechnol. [Internet]. 2011 Sep. 15 [cited 2024 Oct. 7];14(5). Available from: https://www.ejbiotechnology.info/index.php/ejbiotechnology/article/view/v14n5-4

Abstract

The effects of reaction conditions on cyclodextrins (CDs) production by CGTase from newly isolated Bacillus agaradhaerens KSU-A11 is reported. Among six types of starch tested, potato starch gave highest starch conversion into CDs. In addition, CDs yield was about three fold higher when using gelatinized potato starch in comparison to raw starch. The total CDs production was increased with increasing pH, showing maximum starch conversion at pH 10. Furthermore, the proportion of γ-CD was relatively higher under slightly acidic-neutral conditions than at alkaline pH with a maximum proportion of 35.6% at pH 7 compared to 7.6% at pH 10. Maximum starch conversion into CDs was seen at reaction temperature of 55ºC. Lower reaction temperature led to higher proportion of γ-CD with maximum percentage at 35ºC. Cyclization reaction was significantly promoted in the presence CaCl2 (10 mM), while in the presence of ethyl alcohol there was significant decrease in CD production particularly at high concentration. β-CD was the major product up to 1 hr reaction period with traces of α-CD and no detectable γ-CD. However, as the reaction proceed, γ-CD started to be synthesised and α-CD concentration increased up to 4 hrs, where the CDs ratios were 0.27:0.65:0.07 for α-CD:β-CD:γ-CD, respectively. In addition, optimum CGTase/starch ratio was obtained at 80 U/g starch, showing highest starch conversion into CDs. All the parameters involved have been shown to affect the products yield and/or specificity of B. agaradhaerens KSU-A11 CGTase.

Full Text
Reprint PDF

Upon acceptance of an article by the journal, authors will be asked to transfer the copyright to Electronic Journal of Biotechnology, which is committed to maintain the electronic access to the journal and to administer a policy of fair control and ensure the widest possible dissemination of the information. The author can use the article for academic purposes, stating clearly the following: "Published in Electronic Journal of Biotechnology at DOI:10.2225/volXX-issueX-fulltext-XX".

The Copyright Transfer Agreement must be submitted as a signed scanned copy to biotec@ucv.cl. All authors must send a copy of this document.