Fig. 3.

Fermentation performance of wild-type strains and strains with mutated LpXIs integrated into the chromosome in glucose/xylose co-fermentation under micro-aerobic conditions. Batch fermentation examinations were performed under the same conditions as in Fig. 2. The fermentation properties of control strain SS81 (wild-type LpXI) and four representative strains having improved d-xylose consumption rates are shown: SS82 (LpXI-T63I/A121A), SS89 (LpXI-L78S), SS92 (LpXI-V162A/T273T/N303T) and SS93 (LpXI-R191K/E192K). The mutated LpXI expression cassettes were introduced into the AUR1 locus of the chromosome of the parental strain SS29 via homologous recombination. The dots and error bars in the panels represent the mean concentrations and standard deviations, respectively, of the following metabolites in biological triplicates: glucose (blue), xylose (red), xylitol (yellow green), glycerol (purple), acetate (light blue) and ethanol (orange). The details for the metabolite concentrations are shown in Additional file 7: Table S5