3.2 Cultivation
The cultivation results are summarized in Figures S1and S2 . Figure S1 indicates the time courses of cell growth as OD660. Figure S2 demonstrates the time courses of GFP fluorescence intensities. In the control experiment using M9 minimal medium (Figure S1U and Figure S2U), the cell growth was weak and the final yield was 1.11±0.25. GFP production was also weakly induced, and the final GFP yield was 1.83×104±1.52×102 after 9 h. All of the yeast extracts stimulated cell growth and GFP expression. Cell growth and GFP drastically increased between 2 h and 4 h after inoculation, and then the curves plateaued or decreased slightly. The fold changes in growth after adding yeast extracts were between 2.72 and 4.50, and E3 was the best enhancer. The fold changes in GFP were between 1.62 and 2.84, and the best enhancer was E4. Experimental-grade yeast extracts tended to stimulate more cell growth and GFP production than manufacturing-grade yeast extracts. Interestingly, mixing both experimental-grade and manufacturing-grade yeast extracts increased the cell growth and GFP production.