Figure 4.

GOX stability at different temperatures. Time course of residual GOX activity was measured after incubation at (A) 37°C; (B) 55°C, and (C) 60°C. Activity measurements were always carried out at 37°C and pH 4.5. Each point is the mean of a duplicate assay. The error bars show standard deviations. 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 Methods section. Standard: commercial GOX from A. niger (Product B6916, Sigma, USA).