Exponential growth, inclusion body

In each culture the fraction of cells containing visible inclusion reached an approximately constant value during exponential phase growth (Figure 4). As the cells reached late exponential or early stationary phase the fraction then rose sharply so that eventually 90-95% of the cells contained at least one inclusion body. 

Bodies. The fraction of cells containing inclusion bodies was constant during exponential growth for a single inoculum, but depended strongly on the density... 

Figure 6. Influence of inoculum density on the fraction of cells containing inclusion bodies during exponential growth (10 - 10 CFU/mL).

The fraction of cells which contained visible inclusion bodies during exponential growth was constant but depended on the inoculum size. Larger inocula yielded cultures with significantly fewer inclusion body containing cells. The amount of prochymosin correlated to the number of ceUs showing visible inclusions. 

This model for inclusion body formation explains why only one inclusion body forms per cell. Under the assumption of exponential growth, all of the cells always have one pole between 0 and 1 generation old. If one generation is not enough time to synthesize enough protein to form a visible inclusion then one cell pole must be free of inclusion bodies. 

The observations made in this study on inclusion body formation are explained by a pole age model of ceU growth. The constant fraction of cells with inclusion b ies during exponential growth is a consequence of segmentation of ceU cytoplasmic regions by the nuclear material in the cell, and the fact that inclusion bodies are discrete objects which cannot migrate from one end of the... 

The pole age model does not explain why low inoculum densities resulted in a higher fraction of the cells with visible inclusion bodies and higher synthesis rates for prochymosin without decreasing the exponential specific growth rate in the cells. 

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