Aspergillus niger IMI 303386 produced higher levels of intra-and extracellular beta-fructofuranosidase and inulinase on inulin than on sucrose. Intracellular beta-fructofuranosidase from sucrose medium catalysed the best transfructosylation reaction. The concentration of fructooligosaccharides (FOS) reached a maximum in 72 h with 25% (w/v) sucrose. The FOS were purified and the main products were kestose and nystose. Inulinase hydrolysed inulin in an exofashion and released mainly fructose.