Figure 1.

The OsmY(WT)-Tfu0937 activity in the spent medium was measured with the pNPG assay using an absorbance at 405 nm. (a) The pNPG assay was performed in a 96-well microplate for OsmY(WT)-Tfu0937-expressing C41(DE3) cells cultivated in a 96-well deep well plates. The coefficient of variance was calculated using the absolute values measured at 405 nm. (b) The pNPG assay was conducted using 5–50 µL of spent medium. The activity value is linear to the volume of spent medium used with an R² = 0.992.