Naslov
Lipase catalyzed synthesis of glucose palmitate in ionic liquid

Autori
Gubicza, László ; Megyeri, Gábor ; Nemestóthy, Nándor ; Bélafi-Bakó, Katalin ; Findrik Blažević, Zvjezdana

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

Izvornik
Biotrans 2015 / - Beč : TU Wien Academic Press, 2015, 481-481

Skup
Biotrans 2015

Mjesto i datum
Beč, Austrija, 26.07.2015. - 30.07.2015

Vrsta sudjelovanja
Poster

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
lipase; sugar fatty acid ester; esterification; non-conventional media

Sažetak
Sugar fatty acid esters are odorless and tasteless compounds used as surfactants in food, cosmetic and pharmaceutical industry. The choice of solvent for their enzymatic synthesis is very difficult, because one reactant is polar (sugar), the other is nonpolar (fatty acid) and the resulting product is amphiphilic (sugar ester) [1]. In addition, most enzymes are quickly inactivated under hydrophilic organic solvents which are able to dissolve high concentration of both sugars and fatty acids [2]. The use of ionic liquids (ILs) as reaction media can enhance the reactivity, stability and selectivity of enzymes, however, the choice of ILs is not simple as well.In our work glucose palmitate synthesis by esterification of glucose and palmitic acid catalyzed by Novozyme 435 was carried out in three ILs: Cyphos 104, Cyphos 109 and [bmim][PF6]. The equilibrium conversion, as well as the amount of produced ester was the highest in the latter, i.e. X = 77%, 0.115 mmol g-1 of ester. Hence, it was chosen for further experiments. The enzyme was reused for four times at 50 and 70°C to evaluate its stability in [bmim][PF6]. It was found that the enzyme activity slowly decreases at both temperatures. The reaction conditions in [bmim][PF6] were optimized to achieve the best reaction yield or conversion using the factorial design of experiments. In the investigated variable range the highest concentration of ester that could be achieved after 48 h was 0.205 mmol g-1 at 70 °C, equimolar concentrations of substrates of 0.5 mmol g-1 and 0.5% of water. The highest substrate conversion after 48 h was 71%, and it could be achieved at 0.5 mmol g-1 of glucose, 0.15 mmol g-1 of palmitic acid, 0.1% of water and 70 °C. Since it takes more than 48 h to achieve equilibrium conditions, the equilibrium conversion and ester concentration at optimal conditions are even higher.

Izvorni jezik
Engleski

Znanstvena područja
Kemijsko inženjerstvo, Biotehnologija

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