Table 1. Structure of the carbohydrate compounds used for primary and secondary screening and number of hit clones isolated from the fecal (F) and the ileum mucosa (I) libraries.
| compounds | Screening stepse | Structure | Number of hit clones (Hit yield) | |
| F library | I library | |||
| XOSa | 1 and 2 | Xyl-β(1,4)-[Xyl]n (1≤n≤7) | 4 (0.20‰) | 27 (1.35‰) |
| FOSa | 1 and 2 | Glc-α(1,2)-[β(1,2)-Fru]n (1≤n≤4) | 7 (0.35‰)b | 8 (0.4‰)b |
| Inulin | 2 | Glc-α(1,2)-[β(1,2)-Fru]n (10≤n) | 7 (0.35‰) | 8 (0.4‰) |
| AZCL-galactan | 1 | [β(1,4)-Gal]n (n≈100) | 107 (0.79‰) | NTd |
| GOSa | 2 | [β(1,4)-Gal]n-Gal-β(1,4)-Glc (0≤n≤14) | 107 (0.79‰)c | 11 (0.55‰)c |
| Lactulose | 1 and 2 | Gal-β(1,4)-Fru | NTd | 14 (0.7‰) |
a
XOS, xylo-oligosaccharides; FOS, fructo-oligosaccharides; GOS, galacto-oligosaccharides.
b
Clones positive on fructo-oligosaccharides were further assayed for inulin degrading activity.
c
Clones positive on lactulose (I library) and those identified by screening the entire F library (136, 000 clones) on AZCL-galactan were further assayed on galacto-oligosaccharides.
d
NT: non tested.
e
Screening steps: 1, high-throughput primary screen; 2, HPAEC-PAD based secondary screen.