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Oligosaccharide formation and the production of transfructosylase and transglucosylase by Aureobasidium pullulans were studied in sucrose or maltose media, respectively. The initial uptake rates of substrate in sucrose-rich media were faster than that in maltose-rich media, also most parts of oligosaccharides formed and other monosaccharides released were utilized progressively as substrate during the cultivation periods. Howeve;when the initial amount of sucrose was raised to 100g/P, high concentration of monosaccharides were liberated, consequently high-level fructose was accumulated unused during fermentation. ´Me biggest molecule of oligosaccharide synthesized was hexasaccharide in all cultivation media examined, of which the organism could not utilize isomalto-oligosaccharide of DP6 synthesized in a maltose-rich medium. ´e maximum amount of oligosaccharides produced was 58g/P when 100g/P of sucrose and 5g/P of maltose were used as initial substrate. From the early stage of growth, both fructooligosaccharides and isomalto-oligosaccharides were synthesized and progressively utilized as substrates during the fermentation. Based on the experimental results, it was suggested that maltose could induce both transfructosylase and transglucosylase, whereas sucrose was unable to stimulate transglucosylase formation.
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