Organophosphorus compounds are widely used in many pesticides (Paraoxon, Parathion, Coumaphos, and Diazinon) and chemical nerve agents (Sarin and Soman). Organophosphorus hydrolase (OPH) from Pseudomonas diminuta or Flavobacterium sp. is a homodimeric organophosphotriesterase that can degrade a broad spectrum of toxic organophosphates. This enzyme can hydrolyse various phosphorus-ester bonds including P-O, P-F, P-CN, and P-S bonds. The application of OPH for bioremediation is of great interest due to its high turnover rate. Recombinant E. coli expressing OPH can degrade a variety of organophosphates. The ability of E. coli to grow into much higher cell densities than P. diminuta and Flavobacterium enables the development of large-scale detoxification processes. However, recombinant E. coli has a low production yield of OPH due to its very low solubility. Therefore, several strategies have been attempted to enhance OPH production yield or bioconversion efficiency such as insertion of multiple gene fusions, fusion with a soluble partner to increase solubility, and display on cell surface. We have been studying on several cellular redesigns for development of new recombinant whole cell biocatalysis bioconversion system. The attempted strategies for cellular redesign include enhancement of cellular OPH expression and localization control of OPH expression into periplasmic space or cell surface.