ABSTRACT
Whole cells made permeable by chemical or physical treatment allow the conversion of substrates to useful, expensive products. Permeabilized cells are useful if substrate or product or both cannot enter the cell. As many commercially interesting bioconversions require cofactor-dependent enzymes, regeneration of expensive cofactors is necessary. This is possible in permeabilized cells. Thus, permeabilized cells are useful in bioconversions in which cofactors are required and substrates or products or both are not taken up or released by intact cells. In the future the integration of bioconversion, permeabilization, and downstream processing will certainly open new possibilities. Permeabilized cells do not carry out reactions that are catalyzed by membrane-dependent enzymes. Permeabilized cells can be a good tool for bioconversions, especially in microorganisms. As permeabilization of cells is most often achieved with organic solvents, the latter can serve at the same time for the solubilization of hydrophobic substrates and products.
