ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Production of high-content galacto-oligosaccharides mixture using β-galactosidase and Kluyveromyces marxianus entrapped in polyvinylalcohol gel

Silvia Tokošová, Helena Hronská, and Michal Rosenberg

Institute of Biotechnology, Faculty of Chemical and Food Technology in Bratislava, Slovak University of Technology in Bratislava, Radlinského 9, 81237 Bratislava, Slovak Republic

E-mail: helena.hronska@stuba.sk

Abstract: The production of a high-content galacto-oligosaccharides mixture (GOS) by immobilised β-galactosidase and yeasts in LentiKats® lens-shaped polyvinylalcohol (PVA) capsules was evaluated. Galacto-oligosaccharides were produced from lactose (300 g L^-1) by immobilised fungal β-galactosidase and the yeast Kluyveromyces marxianus in polyvinylalcohol hydrogel in batch mode. The low-content GOS mixture produced by the immobilised enzyme consisted of 71.7 g L^-1 with a final purity of 22.7 % after 30 h of transgalactosylation reaction at 30°C and pH 4.5. The low-content GOS mixtures were subsequently used in 20 repeated batch runs with immobilised yeasts for increasing the GOS content. Digestible sugars were fermented to ethanol and the resulting mixture consisted of 88 mass % of GOS after 26 h of fermentation. The PVA lenses exhibited high fermentative stability without any mechanical deformations.

Keywords: galacto-oligosaccharide – β-galactosidase – immobilisation – LentiKats® – yeast

Full paper is available at www.springerlink.com.

DOI: 10.1515/chempap-2016-0081

Chemical Papers 70 (11) 1445–1451 (2016)