In this run without in situ extraction the medium had to be con- tinuously refreshed with a dilution rate of 0.75d−1 to keep cell numbers constant, giving a net specific growth rate of 0.75 d−1 . This is 1.3 times higher than the total growth rate in the first run with in situ extraction.
In Fig. 5 the cell concentration in the reactor for this run is shown, together with the cellular carotenoid content and cell size. With a cell concentration of 1.2 × 109 cells LRV −1 and a cellular -carotene