Synthetic materials colonization by Aureobasidium pullulans fungi for fructo-oligosaccharides production

Fructo-oligosaccharides (FOS) are fructose oligomers with important functional properties [1]. They have been mainly used in food and pharmaceutical industries, as non-digestible and non-cariogenic sweeteners. FOS are known also to control the intestinal flora and thus prevent and treat a large number of intestinal disorders [2]. At the industrial scale, FOS can be produced by microbial transfructosylating enzymes, such as Aureobasidium pullulans enzymes, through sucrose [3]. Cells immobilization can be performed in order to increase the yield and the percentage of FOS in a mixture, since it allows obtaining more concentrated and stable cell cultures [4]. The improved performance of the immobilization systems is although dependent of the accurate selection of the suitable carrier to be used through fermentations [5].
The capacity of A.pullulans to colonize different synthetic materials, namely, foams, vegetal and synthetic fibers, clay, pumice, porous stone and glass wool, was evaluated. Cells were immobilized through direct contact to the carriers at the beginning of the batch fermentations.