Factorial Design to Optimize Biosurfactant Production by Yarrowia lipolytica

Table 6

Experimental design and results of the central composite design.

Run	𝑧^a1	𝑧^a4	C/N	EI^b	ST^c
1	−1	−1	5.9	51.4	11.8
2	+1	−1	10.4	66.2	13.6
3	−1	+1	13.3	60.8	12.9
4	+1	+1	17.8	67.3	16.0
5	−1.41	0	8.7	54.1	12.1
6	+1.41	0	15.1	57.8	15
7	0	−1.41	6.6	61.4	12.4
8	0	+1.41	17.1	73.7	16.2
9	0	0	11.9	81.8	19.5
10	0	0	11.9	81.1	19.0
11	0	0	11.9	80.9	20.1

aThe coded variables 𝑧_𝑖 (𝑖 = 1, 4) are defined in Table 5. bEmulsification index (%) Variation in surface tension (mN m⁻¹)c.