strain comparison in glucose-xylose fermentations on defined substrates and in high-gravity SSCF: convergence in strain performance despite differences in genetic and evolutionary engineering history.

The most advanced strains of xylose-fermenting still utilize xylose far less efficiently than glucose， despite the extensive metabolic and evolutionary engineering applied in their development. Systematic comparison of strains across literature is difficult due to widely varying conditions used for determining key physiological parameters. Here， we evaluate an industrial and a laboratory strain， which has the assimilation of xylose via xylitol in common， but differ fundamentally in the history of their adaptive laboratory evolution development， and in the cofactor specificity of the xylose reductase (XR) and xylitol dehydrogenase (XDH).