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Table 3 In vitro NAD+ reduction activity of various strains

From: Increasing the metabolic capacity of Escherichia coli for hydrogen production through heterologous expression of the Ralstonia eutropha SH operon

Strain Relevant genotype μmol NADH min-1mg-1
R. eutropha H16 Wild type 6.1 ± 0.4
 FTD147   ΔhyaB ΔhybC ΔhycE 0
 JW135   Δhya-Km, Δhyb-Km 0.04 ± 0.009
 FTD147 +pJWPH5 ΔhyaB ΔhybC ΔhycE 0.94 ± 0.16
 JW135 +pJWPH5 Δhya-Km, Δhyb-Km 1.09 ± 0..003
 FTGH2 +pJWPH5 FTD147 adhE, ldhA, mdh 3.9 ± 0.06
 FTJWDC3 +pJWPH5 FTD147 adhE, mdh 6.4 ± 0.10
 JWGH1 +pJWPH5 JW135 adhE, ldhA, arcA 7.1 ± 0.31
 DJ1 +pJWPH5 JW135 arcA 4.45 ± 0.003
 DG2 +pJWPH5 FTD147 adhE, ldhA, arcA 3.56 ± 0.11
 FTDPH10 +pJWPH5 FTD147 adhE, ldhA 3.5 ± 0.1
  1. The in vitro NAD-linked hydrogenase activity of extracts of anaerobically grown cultures of R. eutropha H16, E. coli FTD147, and E. coli FTAB1 were assayed spectrophotometrically (Schneider and Schlegel (1976)). Twenty μg of extract were incubated in a stoppered cuvette containing 1.9 ml of hydrogen-saturated Tris buffer (50 mM, pH 8, 30C°) that had been flushed with hydrogen. The reaction was initiated by the addition of NAD+ to 0.8 mM, and the reduction of NAD+ followed at 365 nm.