Erythritol production on D-xylose. The T. reesei (a) wild-type strain (blue bars) and the thereof derived err1 overexpression strain QPEC1 (red bars) as well as (b) Rut-C30 (blue bars) and the thereof derived err1 overexpression strain RPEC1 (red bars) were cultivated in shake flasks on D-xylose. Samples were taken after the indicated time and erythritol concentration was determined by GC-analysis from cell free extracts. Biological experiments (cultivations) were performed in duplicates. Standard deviations were obtained from two biological duplicates and measurements in triplicates each.