FIG 3.

In vitro enzyme assays with intracellular extracts of E. coli BL21(DE3) cells expressing the three candidate genes FEZ21_09870 (red lines), PP_3839 (green lines), and calA (PP_2426) (purple lines) and the negative-control pNIC28-Bsa4KpnI (blue lines), with two different substrates (vanillyl alcohol and coniferyl alcohol) and two different redox cofactors (NAD⁺ and NADP⁺) in order to determine the preference of each enzyme for substrates and cofactors. Due to overlap in the absorbance (Abs) of products and reduced cofactors, the monitored absorbance was shifted from 340 to 365 nm, and no activity units were calculated. Experiments were performed in duplicate, and the standard deviations are displayed with error bars.