Enhancement of Antibacterial Activity of Paludifilum halophilum and Identification of N-(1-Carboxy-ethyl)-phthalamic Acid as the Main Bioactive Compound

Table 3

Box–Behnken design with observed and predicted values of biomass production (Y₁) and antibacterial activity (Y₂) after 7 days of P. halophilum SMBg3 culture.

Run	Independent variable			Y 1: biomass production (mg/mL)		Y 2: antibacterial activity (mm)
	X 1 (T, °C)	X 2 (pH)	X 3 (% MgSO4·7H2O)	Observed	Predicted	Observed	Predicted
1	−1	−1	0	7	6.34	12	11.55
2	1	1	0	8.30	9.6	13	13.13
3	−1	1	0	10.2	8.88	13	12.92
4	1	1	0	7.80	8.57	10	10.54
5	−1	0	−1	6.6	8.03	13.5	14.04
6	1	0	−1	9.6	8.76	10.5	10.37
7	−1	0	1	6.6	7.45	12	12.06
8	1	0	1	11	9.67	15.5	14.92
9	0	−1	−1	4.7	4.02	12.7	12.66
10	0	1	−1	3.7	3.94	11.7	11.43
11	0	−1	1	3.3	3.52	13	13.33
12	0	1	1	4.1	4.94	13.3	13.33
13	0	0	0	6.6	5.76	10	11.47
14	0	0	0	5.6	5.76	11.50	11.47
15	0	0	0	4.2	5.76	13	11.47
16	0	0	0	4.6	5.76	11	11.47