Figure 4

Cultivation of the wild-type and err1 overexpression strains on wheat straw. The T. reesei wild-type strain (blue bars), and the err1 overexpression strains QPEC1 (red bars) and QBEC2 (yellow bars) were cultivated in bench-top bioreactors on pretreated wheat straw. Samples were taken after 48 and 72 h. (a) Sodium soluble protein concentration (given in g/l cultivation broth) was measured in triplicates in cultivation broth samples after cell disruption to indicate biomass formation. Standard deviations were below 5%. (b) Xylanase activity (given in U/l cultivation broth) was measured in triplicates in the cultivation supernatants. Standard deviations were below 5%. (c) Erythritol concentration (given in mg/l cultivation broth) was measured in triplicates by GC in cultivation broth samples after cell disruption. Error bars indicate standard deviations. (d) Transcript analysis of err1 (given as relative transcript ratio in logarithmic scale (lg)) was performed by qPCR in triplicates using sar1 and act1 as genes for data normalization and levels always refer to the wild-type strain cultivated for 48 h (as indicated by an asterisk). Error bars indicate standard deviations. Biological experiments (cultivations) were performed in duplicates.