Naslov
The influence of calcium ions on α -amylase stabilization during starch hydrolysis

Autori
Visković, Katica ; Vrsalović Presečki, Ana ; Findrik, Zvjezdana ; Vasić-Rački, Đurđa

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, ostalo

Izvornik
1st Conference on ˝Applied Biocatalysis˝ and 5th meeting of students and university professors from Maribor and Zagreb, Book of Abstracts / Habulin, Maja ; Primožič, Mateja - Maribor : Tiskarna tehniških fakultet Maribor, 2009, 65-66

ISBN
978-961-248-153-7

Skup
1st Conference on ˝Applied Biocatalysis˝ and 5th meeting of students and university professors from Maribor and Zagreb

Mjesto i datum
Maribor, Slovenija, 26.05.2009. - 27.05.2009

Vrsta sudjelovanja
Predavanje

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
 -amylase; starch hydrolysis; modelling

Sažetak
Starch hydrolysis is enzymatic process which is usually carried out in two stages: the first step is liquefaction catalyzed by  -amylase, and the second step is the saccharification process catalyzed by glucoamylase [1]. Glucose as the reaction product can be further used as a substrate for ethanol production during fermentation, as raw material for chemical synthesis (sorbitol), or it can be used for the production of fructose by isomerization [2]. Starch liquefaction catalyzed by two  -amylases: Termamyl and Liquozyme was studied in this work. Considering that both enzymes deactivate during the prolonged use at high temperatures (65 and 80 °C), the possibility of their stabilization by Ca2+ ions was studied [3]. The experiments were carried out at two temperatures (65 and 80 °C) and in the repetitive batch and fed batch reactors for both enzymes in the presence of 5 mM calcium ions. Mathematical models for different reactor types were developed and enzyme deactivation constants were estimated. The enhancements on the  -amylases stability by calcium ions were observed at both temperatures. Those were confirmed by significantly lower deactivation constants estimated in the experiments, which were carried out in the presence of calcium ions. The impact of calcium ions on the activity of glucoamylase (Dextrozyme) was investigated at the temperature of 65 °C and considerable stabilization effect was also observed in the case of this enzyme.

Izvorni jezik
Engleski

Znanstvena područja
Biotehnologija

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