Heterologous Ectoine Production in Escherichia coli: Optimization Using Response Surface Methodology

Table 1

Experimental design for optimization of ectoine production by the recombinant E. coli.

Variable	Parameter	Level
Equations (1) and (2)	Optimization I	−1.682	−1	0	1	1.682
X1	Glucose (% w/v)	0.3	0.6	1.0	1.4	1.7
X2	NaCl (% w/v)	0.1	0.6	1.4	2.2	2.7
X3	Temperature (°C)	15	21	30	39	45
Equations (3) and (4)	Optimization II	−1.414	−1	0	1	1.414
X1	OD before induction	0.3	0.4	0.8	1.1	1.2
X2	Final concentration of inducer (mM)	0.1	0.3	0.8	1.3	1.5