Fig. 1
Metabolic engineering for xylitol biosynthesis from various carbon sources in P. pastoris. A high-yield xylitol-producing cell factory was constructed by introducing two synthetic pathways, enhancing the pentose phosphate pathway, performing enzyme engineering, and optimizing fermentation conditions. The engineered strain is capable of producing xylitol from C1, C3, and C6 carbon sources, including methanol, glycerol, and glucose. The key enzymes encoded by the genes used in this study are: ZWF, glucose6-phosphate dehydrogenase; PGL, phosphogluconolactonase; GND, Phosphogluconate dehydrogenase (decarboxylation); RPE, ribulose-phosphate-3-epimerase; Xks1, xylulose kinase; AraL, xylose phosphatase from B. subtilis; KpDalD, D-arabitol dehydrogenase from K. pneumoniae; PsXyl2, xylitol dehydrogenases from P. stipitis