Fig. 1

Scheme of reconstruction of cellobiose-utilizing and xylose-utilizing pathway in C. glutamicum ATCC 13032. C. glutamicum wild-type is not able to utilize cellobiose and xylose as sole carbon source (left). No genes for xylose isomerase, cellobiose transporters, and β-glucosidase are annotated (shown as no arrow). Through metabolic engineering and adaptive evolution of C. glutamicum strains (right), the cells were able to utilize cellobiose and xylose. Extracellular cellobiose was transported and intracellular β-glucosidase encoded by the gh1-1 gene hydrolyzed intracellular cellobiose to glucose, which further was metabolized by glucokinase (Glk) into glycolysis. Xylose metabolic pathway consists of heterologous xylose isomerase (xylA from E. coli) and additional xylulose kinase (xylB from E. coli). Transporter of Gxf1 (Candida intermedia) and Sut1 (Pichia stipitis), respectively was introduced as a xylose transporter