Biology Reference
In-Depth Information
increased Hydrogen
Production by Genetic
Zhanmin Fan, Ling Yuan and Ranjini Chatterjee
AbstrAct
Escherichia coli is capable of producing hydrogen under anaerobic growth
conditions. Formate is converted to hydrogen in the fermenting cell by the for-
mate hydrogenlyase enzyme system. The specific hydrogen yield from glucose
was improved by the modification of transcriptional regulators and metabol-
ic enzymes involved in the dissimilation of pyruvate and formate. The engi-
neered E. coli strains ZF1 (
∆
focA; disrupted in a formate transporter gene)
and ZF3 (
∆
narL; disrupted in a global transcriptional regulator gene) pro-
duced 14.9, and 14.4 µmols of hydrogen/mg of dry cell weight, respectively,
compared to 9.8 µmols of hydrogen/mg of dry cell weight generated by wild-
type E. coli strain W3110. The molar yield of hydrogen for strain ZF3 was
0.96 mols of hydrogen/mol of glucose, compared to 0.54 mols of hydrogen/
mol of glucose for the wild-type E. coli strain. The expression of the global
