Naslov
Immobilization of biocatalyst within microchannel

Autori
Šalić, Anita ; Pindrić, Katarina ; Purić, Jelena ; Zelić, Bruno

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

Izvornik
Book of Abstracts of the 11th International Chemical and Biological Engineering Conference / - Lisabon : Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, 2011, 211-212

Skup
11th International Chemical and Biological Engineering Conference

Mjesto i datum
Lisabon, Portugal, 05.09.2011. - 07.09.2011

Vrsta sudjelovanja
Poster

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
microchannel; immobilisation; alcohol dehydrogenase; baker’s yeast; mathematical model

Sažetak
Microreaction technology is gaining important place in different fields of application from scientific researches to industrial production. Large surface area to volume ratio, very effective heath and mass transfer, better process control and new production concepts by numbering up instead of scale-up, are advantages what makes them so interesting (Žnidaršić – Plazl and Plazl, 2009). Important area of investigation in this field is use of enzymatic microreactors. Based on their application enzymatic microreactors can be divided in two types, those used for biotransformation and those used for screening substrates, enzymes and examine their kinetics (Urban et al., 2006). In enzyme microreactors, enzymes can be used as dissolved or as immobilized. Immobilization of enzymes in microreactors could be performed by covalent immobilization or by co-polymerization (trapping the enzyme in a polymer) (Posthuma-Trumpie et al., 2007). Hexanal is a part of the group of the natural volatile chemicals, so called “green notes”. They are used to impart a green sign associated with freshness (Santiago-Gómez et al., 2009) and their organoleptic fresh note is what makes them so interesting for the consumer in the pharmaceutical, agrochemical and aroma industry (Shade et al, 2003). Nowadays, several methods are applied for green chemical production: halogenation of alkyl aromatics followed by hydrolysis, vapor-phase oxidation of alkyl aromatics and reduction of acid halides hydrogenation of carboxylic acids by molecular hydrogen and oxidation of dehydrogenation of aromatic alcohols (Yokoyama and Yamagata, 2001). Main problem of these traditional methods is that due to low yields, formation of unwanted by- products and large quantities of wastes they can not provide a sufficient amounts of green chemicals (Akacha and Gregouri, 2009). Application of microreactors could be the next generation of producing process, and biotransformation in microreactors, after process optimization, could be a good alternative to classical chemical synthesis processes. In this study, aplication of microchannels with immobilised biocatalysts was explored. Enzymatic oxidation of hexanol to hexanal using immobilized NAD+ dependent commercial alcohol dehydrogenase (from S. cerevisiae) and immobilized whole baker’s yeast cells was performed. The catalysts were immobilized on the surface of polytetrafluoroethylene (PTEF) microchannel wall. Reaction was carried out in continuously operated microchannel at different flow rates (0 – 200 μL/min). In experiments with whole baker’s yeast cells they were permeabilized in order to enhance mass transfer through cell membrane. Obtained results, both with immobilised enzymes and immobilized whole baker’s yeast cells, were compared with results from batch experiments (Vrsalović-Presečki, 2006) and microreactor experimenst performed with enzyme suspension. A mathematical model for the hexanol oxidation catalysed by immobilised NAD+ dependent alcohol dehydrogenase from baker’s yeast in microchannel was developed. Enzyme kinetics was described with the double substrate Michaelis-Menten equation, where kinetic constants were estimated independently from initial reaction rate experiments in microreactor. Based on results and good agreement between model predictions and experimental results, obtained model simulation results could be used for further process optimization and development of new microreactors.

Izvorni jezik
Engleski

Znanstvena područja
Kemijsko inženjerstvo

Napomena
Ovaj se tekst temelji na radu koji je financirala Nacionalna zaklada za znanost, visoko školstvo i tehnologijski razvoj Republike Hrvatske.

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