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

Table 3

Estimated coded coefficients and values for ectoine production by recombinant E. coli, optimized using response surface methodology.

Factor	Coefficient	value
Intracellular ectoine (g/L)
Linear
X1	0.00047	0.781
X2	0.00786	0.000
X3	−0.00015	0.921
Square
	−0.00140	0.402
	−0.01084	0.000
	−0.00978	0.000
Interaction
X2X3	0.01042	0.000
Extracellular ectoine (g/L)
Linear
X1	−0.0070	0.499
X2	−0.0717	0.000
X3	0.0356	0.004
Square
	−0.02001	0.061
	−0.02468	0.025
	−0.03795	0.002
Interaction
X2X3
Productivity (mg ect./g cdw)
Linear
X1	2.81	0.121
X2	27.55	0.000
X3	−24.88	0.000
Square
	4.68	0.016
	6.10	0.004
	11.55	0.000
Interaction
X2X3	−12.10	0.000

Significant, X₁ = glucose, X₂ = NaCl, and X₃ = temperature.