Evaluation of an oxygen‐dependent self‐inducible surfactin synthesis in B. subtilis by substitution of native promoter PsrfA by anaerobically active PnarG and PnasD

AMB Express

Table 3 Summary of main process data, calculated overall yields and specific growth rates of B. subtilis bioreactor cultivations

Strategy	Reference pO₂ set-point 20%	Fed-batch, constant aeration of 2 L/min		Fed-batch, constant aeration of 1.2 L/min		Fed-batch, constant aeration of 1.2 L/min
Evaluation until	End of batch	After batch glucose consumption	End of process	After batch glucose consumption	End of process	After batch glucose consumption	End of process
B. subtilis strain	JABs24	MG1		KM1016		MG14
Time of cultivation (h)	24	22	40	26	46	19	46
CDW_max (g)	77.51	104.55	196.97	61.54 ± 9.21	147.52 ± 8.22	55.78 ± 13.24	150.18 ± 3.33
Surfactin_max (g)	57.43	51.65	104.57	48.47 ± 11.81	82.14 ± 0.91	15.49 ± 6.40	31.56 ± 3.74
Y_P/X (g/g)	0.741	0.494	0.531	0.776 ± 0.088	0.557 ± 0.024	0.266 ± 0.039	0.211 ± 0.030
Y_X/S (g/g)	0.145	0.249	0.195	0.161 ± 0.011	0.131 ± 0.005	0.134 ± 0.016	0.123 ± 0.003
Y_P/S (g/g)	0.108	0.124	0.103	0.127 ± 0.022	0.073 ± 0.001	0.036 ± 0.010	0.026 ± 0.004
q (g/(g∙h))	0.031	0.022	0.013	0.030 ± 0.003	0.012 ± 0.001	0.014 ± 0.002	0.004 ± 0.001
µ (1/h)	0.222	0.272	0.165	0.204 ± 0.009	0.134 ± 0.005	0.271 ± 0.010	0.128 ± 0.003