Table 1.

Statistical analysis of the model by Plackett–Burman design for l‐DOPA production.

Source	Sum of squares	d.f.	Mean square	F‐value	P‐value P > F
Model	0.072669	4	0.018167	28.4801	0.0002*
X1 – pH	0.007651	1	0.007651	11.99379	0.0105*
X2 – tryptone	0.00913	1	0.00913	14.31288	0.0069*
X7 – l‐tyrosine	0.049024	1	0.049024	76.85316	< 0.0001*
X8 – CuSO4	0.006864	1	0.006864	10.76056	0.0135*
Residual	0.081013	1	0.081013
Corrected total	0.004465	7

^*Significant P‐values at P ≤ 0.05.