Analysis of neofructooligosaccharides production mediated by the extracellular β-fructofuranosidase from Xanthophyllomyces dendrorhous.

The extracellular β-fructofuranosidase Xd-INV from the yeast Xanthophyllomyces dendrorhous mainly synthesizes the neo-fructooligosaccharides (neo-FOS) neokestose and neonystose. This enzyme is a glycoprotein with a content of 59-67% N-linked carbohydrates and an estimated molecular mass of 160-200 kDa. The extent level of glycosylation affects the thermal behaviour of the enzyme but not its hydrolase and transferase activities, which are optimal at 60-70 °C. The neo-FOS yield of this enzyme was increased from 40 to 168 g/L when the sucrose concentration increased from 420 to 600 g/L and when the reaction was carried out at 60 °C. The neo-FOS levels obtained (168 g/L) in this work are the largest reported for any microbial β-fructofuranosidase.