Open AccessInactivation of the Escherichia coli K‐12 twin‐arginine translocation system promotes increased hydrogen production
Author(s) -
Penfold David W.,
Sargent Frank,
Macaskie Lynne E.
Publication year - 2006
Publication title -
fems microbiology letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.899
H-Index - 151
eISSN - 1574-6968
pISSN - 0378-1097
DOI - 10.1111/j.1574-6968.2006.00333.x
Subject(s) - formate , escherichia coli , mutant , chromosomal translocation , strain (injury) , arginine , chemistry , hydrogenase , hydrogen , biology , translocase , hydrogen production , biochemistry , gene , amino acid , enzyme , catalysis , organic chemistry , anatomy
The effect of deleting the genes encoding the twin‐arginine translocation (Tat) system on H 2 production by Escherichia coli strain MC4100 and its formate hydrogenlyase upregulated mutant (Δ hycA ) was investigated. H 2 evolution tests using two mutant strains defective in Tat transport (Δ tatC and Δ tatA‐E ) showed that the rate doubled from 0.88±0.28 mL H 2 mg dry weight −1 L culture −1 in the parental strain, to 1.70±0.15 and 1.75±0.18 mL H 2 mg dry weight −1 L culture −1 , respectively, in the Δ tatC and Δ tatA‐E strains. This increase was comparable to that of a previously characterized hydrogen over‐producing E. coli strain carrying a Δ hycA allele. Construction of a tatC , Δ hycA double deletion strain did not increase hydrogen production further. Inactivation of the Tat system prevents correct assembly of the uptake hydrogenases and formate dehydrogenases in the cytoplasmic membrane and it is postulated that the subsequent loss of basal levels of respiratory‐linked hydrogen and formate oxidation accounts for the observed increases in formate‐dependent hydrogen evolution.