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Author(s): Neri, David
Balcão, Victor
Costa, Rafael
Rocha, Isabel
Ferreira, Eugénio
Torres, Duarte
Rodrigues, Lígia
Carvalho Jr., Luiz
Teixeira, José
Title: Galacto-oligosaccharides production during lactose hydrolysis by free Aspergillus oryzae β-galactosidase and immobilized on magnetic polysiloxane-polyvinyl alcohol
Issue Date: 2009
Abstract: The synthesis of galacto-oligosaccharides (GOS) by the action of Aspergillus oryzae b-galactosidase freeand immobilized on magnetic polysiloxane-polyvinyl alcohol (mPOS-PVA) was studied. A maximumGOS concentration of 26% (w/v) of total sugars was achieved at near 55% lactose conversion from 50%,w/v lactose solution at pH 4.5 and 40 C. Trisaccharides accounted for more than 81% of the total GOS produced.GOS formation was not considerably affected by pH and temperature. The concentrations of glucoseand galactose encountered near maximum GOS concentration greatly inhibited the reactions andreduced GOS yield. GOS formation was not affected by enzyme immobilization in the mPOS-PVA matrix,indicating the absence of diffusional limitations in the enzyme carrier. Furthermore, this water insolublemagnetic derivative was reutilized 10-times and retained about 84% of the initial activity. In addition, thekinetic parameters for various initial lactose concentrations were determined and compared for the freeand immobilized enzyme.
Subject: Biotecnologia industrial
Industrial biotechnology
Scientific areas: Ciências da engenharia e tecnologias::Biotecnologia industrial
Engineering and technology::Industrial biotechnology
Document Type: Artigo em Revista Científica Internacional
Rights: restrictedAccess
Appears in Collections:FCNAUP - Artigo em Revista Científica Internacional

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