초록
Different filamentous fungi isolated from molasses and jams (kiwi and fig) were screened for fructooligosaccharides (FOS) producing activity. Two strains, identified as Penicilium sizovae (CK1) and Cladosporium cladosporioides (CF<SUB>2</SUB>15), were selected on the basis of the FOS yield and kestose/nystose ratio. In both strains the activity was mostly mycelium-bound. Starting from 600g/L of sucrose, maximum FOS yield was 184 and 339g/L for P. sizovae and C. cladosporioides, respectively. Interestingly, the highest FOS concentration with C. cladosporioides was reached at 93% sucrose conversion, which indicated a notable transglycosylation to hydrolysis ratio. The main FOS in the reaction mixtures were identified by HPAEC-PAD chromatography. C. cladosporioides synthesized mainly 1-kestose (158g/L), nystose (97g/L), <SUP>1</SUP>F-fructosylnystose (19g/L), 6-kestose (12g/L), neokestose (10g/L) and a disaccharide (34g/L) that after its purification and NMR analysis was identified as blastose [Fru-β(2→6)-Glc]. P. sizovae was very selective for the formation of <SUP>1</SUP>F-FOS (in particular 1-kestose) with minor contribution of neoFOS and negligible of levan-type FOS.