We have used the surface of _E. coli_ as a platform to display organophosphate hydrolase (OPH) for OP degradation. The OPH used in this study is a phosphotriesterase obtained from _Pseudomonas diminuta_.(66) Also known as parathion hydrolase, the enzyme specifically degrades synthetic OP triesters and phosphorofluoridates with high catalytic efficiency.(66) With its ability to efficiently degrade these toxic compounds, this OPH has been widely used for remediation purposes.(10,11,33) Using our previously-reported strategy employing the INPNC ice-nucleation sequence, OPH was displayed on the cell surface.(64) The ice-nucleation sequence circumvents the cytotoxic effects of the more common surface expression tag, OmpA.(39) Moreover, the cells are lyophilized following OPH expression, making their viability unnecessary for OP degradation and potentially increasing the length of their storage life(67)—both important for an optimal deployable technology. Extrapolating from previous INPNC _E. coli_ expression, we estimate approximately 50 000 enzymes to be expressed per lyophilized cell using our induction conditions.(64) The degradation of paraoxon by lyophilized OPH-_E. coli_ was confirmed by monitoring the OP degradation product, _p_-NP, using a colorimetric assay (Figure 1).(66) Under alkaline conditions, _p_-NP forms a phenolate ion, which is yellow in color and has a maximum absorbance at 400 nm.(68) The absorbance values obtained from the colorimetric assay were converted to _p_-NP concentrations with the help of a standard curve. We can therefore quantify paraoxon degradation through the production of _p_-NP at a fixed cell density (OD600 0.02) (Figure 1b). At each paraoxon concentration, rapid initial _p_-NP production followed by equilibration was observed. From these data, enzyme kinetic parameters were determined by fitting the Michaelis-Menten equation (Figure 1c). The Michaelis constant (_K_M) of paraoxon for the enzyme was calculated to be 197.9 ± 81.7 μM, which is slightly higher than the reported affinity of paraoxon for purified OPH.(66) This is hypothesized to be due to restricted substrate diffusion to the enzymes that are confined on the cells rather than free in solution.(69) To determine the effect of enzyme concentration on substrate turnover, a fixed concentration of paraoxon was added to varying concentrations of lyophilized OPH-_E. coli_ (Figure S1 [/doi/suppl/10.1021/acscentsci.1c00931/suppl_file/oc1c00931_si_001.pdf]). As anticipated, the initial reaction rate of paraoxon degradation is directly proportional to the cell concentration, and therefore, the OPH enzymes expressed on the _E. coli_ cell surface (Figure 1d). These results indicate that the OPH enzymes on the surface of _E. coli_ retain their biologically-relevant conformation even following lyophilization. The degradation of paraoxon, therefore, does not require viable _E. coli_ to proceed.