Journal of Biotechnology 116 (2005) 347–357 Investigations of the transfructosylation reaction by fructosyltransferase from B. subtilis NCIMB 11871 for the synthesis of the sucrose analogue galactosyl-fructoside I.-E. Baciu, H.-J. J ¨ ordening ∗ , J. Seibel, K. Buchholz Technical Chemistry, Departmentfor Carbohydrate Technology, Technical UniversityBraunschweig, Langer Kamp 5, D-38106 Braunschweig, Germany Received 12 February 2004; received in revised form 4 October 2004; accepted 14 October 2004 Abstract The exo-fructosyltransferase produced from B.subtilis NCIMB 11871 strain transfers the fructose moiety from donor  12 linked saccharides such as sucrose, raffinose and stachyose to the acceptor d-galactose, leading to the sucrose analogue, galactosyl- fructoside. Here, we report detailed kinetic studies. The enzyme showed a remarkably high optimal temperature at 50 ◦ C and was effectively immobilised on Eupergit ® C 250 L and Trisopor ® -Amino. This is also the first report about the equilibrium of the transfructosylation reaction, its activation energy determination, the structure of the product and its preparative scale isolation. © 2004 Elsevier B.V. All rights reserved. Keywords: B. subtillis NCIMB 11871; Fructosyltransferase; Galactosyl-fructoside; Preparative IEC; Eupergit ® C; Trisopor ® -Amino 1. Introduction Oligosaccharides (OS) have been commercialised since the 1980s as alternative sweeteners. More re- cently, they gained much interest as building blocks in pharmaceuticals and functional food. There are several prebiotic OSs on the European and US market, such as inulin type fructans, fructooligosaccharides (FOS), iso- maltooligosaccharides (IMO) (Buchholz and Seibel, ∗ Corresponding author. Tel.: +49 531 234 4784; fax: +49 531 391 7263. E-mail address: a.joerdening@tu-bs.de (H.-J. J ¨ ordening). 2003) and galactooligosaccharides. New alternative sweeteners, on this basis, are important not only be- cause of their sweetness, but also because of their func- tional properties. Some of the desirable characteris- tics of FOSs are: low caloric, safe sugars for diabetics and non-cariogenic (Yun, 1996). Such non digestible food ingredients are better known under the name pre- biotics, that beneficially affect host health by selec- tively stimulating the growth and/ or activity of one or a limited number of bacteria of the microflora in the colon (indigenous Bifidobacterium and Lactobacillus genera), which are generic called probiotics (Rastall and Hotchkiss, 2003). 0168-1656/$ – see front matter © 2004 Elsevier B.V. All rights reserved. doi:10.1016/j.jbiotec.2004.10.019