Investigation of Antimicrobial Activity and Statistical Optimization of Bacillus subtilis SPB1 Biosurfactant Production in Solid-State Fermentation

Table 5

Estimate regression coefficients for biosurfactant production using data in coded units.

Number	Estimate coefficient	F. inflation	Standard deviation	𝑡 experimental	Significance
𝑏0	14.356		0.334	43.02	***
𝑏1	0.313	1.00	0.250	1.26	***
𝑏2	1.070	1.00	0.250	4.29	***
𝑏3	0.607	1.00	0.250	2.43	***
𝑏1-1	0.746	1.01	0.243	3.07	***
𝑏2-2	1.119	1.01	0.243	4.61	***
𝑏3-3	−0.379	1.01	0.242	−1.57	NS
𝑏1-2	1.064	1.00	0.334	3.18	***
𝑏1-3	0.396	1.00	0.336	1.18	***
𝑏2-3	0.138	1.00	0.336	0.41	NS

(***): Significant at the level 99.9%; (NS): nonsignificant at the level 95%.