Efficient production of d-1,2,4-butanetriol from d-xylose by engineered Escherichia coli whole-cell biocatalysts

we have developed a whole-cell bioconversion system for the production of d-1,2,4-butanetriol (bt) from renewable biomass. a plasmid petduet-xylb-yjhg-t7-adhp-t7-mdlc was constructed and transformed to escherichia coli bl21(de3) to obtain the whole cells of e. coli bl21-xyma capable of bioconversion d-xylose to bt. then, the factors including carbon sources, nitrogen sources, metal ions, and culture conditions (ph, temperature, iptg) were identified, and their effects on the whole-cell activity for bt production were investigated. to obtain the highest whole-cell activity, the optimal cultivation parameters are: 15 g·l–1 yeast extract, 5 g·l–1 sucrose, 3 g·l–1 kh2po4, 5 g·l–1 nacl, 3 g·l–1 nh4cl, 0.25 g·l–1 mgso4·7h2o and 1 ml·l–1 the mixture of trace elements. with the optimized whole cells of e. coli bl21-xyma, 60 g·l–1 of xylose was converted to 28 g·l–1 bt with a molar yield of 66 %, which is higher than those reported in the biotechnological system.