The present work was devoted to investigations concerning the fructooligosaccharide producing activity of Cryptococcus sp. LEB-V2 (Laboratory of Bioprocess Engineering, Unicamp, Brazil) and its extracellular fructofuranosidase. After cell separation, the enzyme was purified by ethanol precipitation and anion exchange chromatography. The enzyme showed both fructofuranosidase (FA) and fructosyl transferase (FTA) activity. With sucrose as substrate, the data failed to fit the Michaelis-Menten behaviour, showing a substrate inhibitory model. The K (m), K (i) and v (max) values were shown to be 64 mM, 3 M and 159.6 mu mol mL(-1) min(-1) for FA and 131 mM, 1.6 M and 377.8 mu mol mL(-1) min(-1) for FTA, respectively. The optimum pH and temperature were found to be around 4.0 and 65 degrees C, while the best stability was achieved at pH 4.5 and temperatures below 60 degrees C, for both the FA and FTA. Despite the strong FA activity, the high transfructosylating activity allowed for good FOS production from sucrose (35% yield).2282213221