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

Table 5

Estimated effect, regression coefficient, and corresponding 𝑡 and 𝑃 values for biosurfactant production in central composite design experiments.

Noun	Coefficient	𝐹 Inflation	Ecart-Type	𝑡.exp	Signification
𝑏0	2.877		0.071537292	40.21	***
𝑏1	−0.253	1.00	0.043336447	−5.83	***
𝑏2	−0.056	1.00	0.043336447	−1.03	NS
𝑏3	−0.130	1.00	0.043336447	−3.00	*
𝑏1-1	−0.240	1.00	0.043347065	−5.53	***
𝑏2-2	0.008	1.00	0.043347065	0.18	NS
𝑏3-3	−0.204	1.00	0.043347065	−4.71	**
𝑏1-2	0.100	1.00	0.056621757	1.77	NS
𝑏1-3	0.000	1.00	0.056621757	0.00	NS
𝑏2-3	0.025	1.00	0.056621757	0.44	NS

(***): significant at the level 99.9%.
(**): significant at the level 99%.
(*): significant at the level 95%.
NS: NonSignificant.