Studies on modelling and simulation of lactose hydrolysis by free and immobilized β-galactosidase from Aspergillus niger

Papayannakos, N; Markas, G; Kekos, D

dc.contributor.author	Papayannakos, N	en
dc.contributor.author	Markas, G	en
dc.contributor.author	Kekos, D	en
dc.date.accessioned	2014-03-01T01:41:56Z
dc.date.available	2014-03-01T01:41:56Z
dc.date.issued	1993	en
dc.identifier.issn	03009467	en
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/23673
dc.relation.uri	http://www.scopus.com/inward/record.url?eid=2-s2.0-0027639561&partnerID=40&md5=03af3dfc8ca21d443c1c37f738d5cc12	en
dc.subject.other	Hydrolysis	en
dc.subject.other	PH	en
dc.subject.other	Pollution control	en
dc.subject.other	Waste utilization	en
dc.subject.other	Cottage cheese	en
dc.subject.other	Dairy industry	en
dc.subject.other	Immobilization	en
dc.subject.other	Organic carriers	en
dc.subject.other	Sweetening valve	en
dc.subject.other	Enzyme kinetics	en
dc.title	Studies on modelling and simulation of lactose hydrolysis by free and immobilized β-galactosidase from Aspergillus niger	en
heal.type	journalArticle	en
heal.publicationDate	1993	en
heal.abstract	β-Galactosidase from Aspergillus niger was immobilized effectively on a porous ceramic monolith by adsorption and intermolecular cross-linking. The binding efficiency reached 80% and no enzyme leaching was observed even under vigorous mechanical agitation. Immobilization did not change the pH optimum of lactose hydrolysis. The enzyme decay followed first-order kinetics and the thermal stability of the immobilized lactase was considerably enhanced. At 50 °C and pH 3.6 the half-life of the immobilized lactase was 180 days and that of the free enzyme 24 days. The kinetics of lactose hydrolysis by both free and immobilized lactase were studied in a batch reactor system in the absence of any mass transfer limitations. In both cases the totally competitive galactose inhibition kinetic model predicted the experimental data. Simulation of the performance of a laboratory continuous flow immobilized lactase reactor system showed that experimental results could be predicted by the ideal plug flow model when an apparent effectiveness factor nf=0.65 is used to take into account the external mass transfer limitations. © 1993.	en
heal.journalName	The Chemical Engineering Journal	en
dc.identifier.volume	52	en
dc.identifier.issue	1	en
dc.identifier.spage	B1	en
dc.identifier.epage	B12	en