Figure 3
From: Heterologous expression of glucose oxidase in the yeast Kluyveromyces marxianus
Effect of pH on heterologous GOX activity. (A) GOX activity was measured from pH 3 to 12; and (B) residual GOX activity was measured after 2 hours of enzyme incubation at the corresponding pH (here, activity measurements were always carried out at 37°C and pH 4.5). The following buffers were used: acetate (3.0, 4.0, 5.0); HEPES (6.0, 7.0, 8.0); Tris (9.0, 10.0, 11.0, 12.0). Each point is the mean of a duplicate assay. Km supernatant and Km cell wall: GOX produced by Km2 construction. Kl supernatant and Kl cell wall: GOX produced by Kl1 construction. Both clones were cultivated as described in the Methods section. Standard: commercial GOX from A. niger (Product B6916, Sigma, USA).