Table 3.

Experimental range and levels of independent variables used for central composite design.

Variables	Components	−α	−1	0	+1	+α
A	CMC	2	5.24	10	14.76	18
B	Yeast extract	0.5	2.53	5.5	8.47	10.5
C	NaCl	2	4.43	8	11.57	14