Optimization of the Nutritional Parameters for Enhanced Production of B. subtilis SPB1 Biosurfactant in Submerged Culture Using Response Surface Methodology

Table 1

The various media components included in Plackett-Burman experiments and their corresponding higher, medium, and lower concentration levels.

Variables code	Media constituents	Units	High level (+1)	Medium level (0)	Low level (−1)
𝐹1	Glucose	g/L	40	25	10
𝐹2	Urea	g/L	5	3	1
𝐹3	Ammonium sulfate	g/L	5	3	1
𝐹4	NaCl	g/L	5	2.75	0.5
𝐹5	MgSO4	g/L	2	1.1	0.2
𝐹6	KH2PO4	g/L	2	1.25	0.5
𝐹7	K2HPO4	g/L	2	1.25	0.5
𝐹8	MnSO4	g/L	0.01	0.0055	0.001
𝐹9	FeSO4	g/L	0.01	0.0055	0.001
𝐹10	ZnSO4	g/L	0.01	0.0055	0.001
𝐹11	CaCl2	g/L	0.01	0.0055	0.001