@article{open872, volume = {9}, number = {2}, author = {P R Patnaik}, note = {Copyright of this article belongs to Elsevier Science.}, title = {Enhancement of protein activity in a recombinant fermentation by optimizing fluid dispersion and initial plasmid copy number distribution}, publisher = {Elsevier Science}, year = {2001}, journal = {Biochemical Engineering Journal}, pages = {111--118}, keywords = {Recombinant fermentation; Plasmid copy number distribution; Fluid dispersion; GAPDH activity}, url = {http://crdd.osdd.net/open/872/}, abstract = {Recombinant fermentations carried out in large bioreactors are characterized by incomplete dispersion of fluid and a distribution of plasmid copy numbers among the cells. The effects of both features have been studied for the batch production of glyceraldehyde-3-phosphate dehydrogenase (GAPDH) by E. coli harboring the plasmid pBR Eco gap. GAPDH activity is maximized by a large average copy number (within metabolically permissible limits) of the cell population and intermediate optimal values of its variance and of dispersion in the broth (expressed by the Peclet number). The optimum conditions, however, should be chosen judiciously because, although GAPDH activities are high, the incremental benefits are lower than under non-optimal operation.} }