Yeast XR activity [IU/ml]   NADH NADPH IMB1 IMB2 n.d. n.d. 2.85 2.68 IMB3 n.d. 0.51 IMB4 n.d. 0.26 IMB5 n.d. 2.91

Table 5: XR activity of IMB yeast strains at 40°C (n.d. = non-detectable). The units are in IU/ml (μmol of cofactor oxidized / (ml cell free extract * min)).