                            00.0 ± 0.0                                  00.0 ± 0.0                                              000.0 ± 0.0                                              00.0 ± 0.0                                               000.0 ± 0.0   Phe000Leu                            00.0 ± 0.0                                  000.0 ± 0.0                                             00.0 ± 0.0                                               000.0 ± 0.0                                              00.0 ± 0.0   Phe000His                            00.0 ± 0.0                                  00.0 ± 0.0                                              00.0 ± 0.0                                               000.0 ± 0.0                                              00.0 ± 0.0   Phe000Asn                            00.0 ± 0.0                                  00.0 ± 0.0                                              000.0 ± 0.0                                              00.0 ± 0.0                                               00.0 ± 0.0   Phe000Tyr                            00.0 ± 0.0                                  000.0 ± 0.0                                             000.0 ± 0.0                                              000.0 ± 0.0                                              000.0 ± 0.0  GOS was produced using 0.00 units/mL β-galactosidase wild-type and mutant enzymes with 00% (w/w) lactose \[in 000 mM sodium phosphate buffer (pH 0.0)\] incubated at 00 °C for 00 h.  Yields are calculated as grams of GOS produced from 000 g of initial lactose. Calibration curves for lactose, galactose, and glucose ranging from 00 to 0000 μM were used for quantification.  The yields are relative to that of the wild-type enzyme (000%), estimated by comparing the peak intensities in the HPAEC--PAD profiles.  