Method of determining propensity of dissolved oxygen instability
AssigneeGenentech, Inc.
InventorJames R. Swartz
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Abstract
A process for producing a polypeptide of interest from fermentation of bacterial host cells comprising nucleic acid encoding the polypeptide is provided. In this method, the host cells employed have an inactivated electron transport chain. Further provided is a method for determining if a particular bacterial cell culture has a propensity for dissolved oxygen instability when fermented on a large scale.
Claims9
A method for determining the propensity of a bacterial cell culture for sudden changes in dissolved oxygen concentration in the culture medium in a large-scale fermentor comprising (a) culturing the cell culture in the presence of a carbon/energy source introduced at a set feed rate in a small-scale fermentor configured so that the dissolved oxygen concentration throughout the cell culture is not homogeneous during fermentation, (b) after cell mass has been produced in an amount that brings the dissolved oxygen concentration to zero or nearly zero during growth of the cells, increasing the feed rate of the carbon/energy source, and (c) determining if non-linearity occurs in the slope of dissolved oxygen concentration versus time or if oscillations in dissolved oxygen concentration are induced after the feed rate of the carbon/energy source is increased, wherein a propensity for sudden changes in dissolved oxygen concentration is indicated when either (i) a gradual slope is changed to a rapid slope in a graph of dissolved oxygen concentration vs. time or (ii) oscillations in dissolved oxygen concentration occur with increased carbon/energy source feed rate.
Dependencies are inferred from the claim text.