Enhancement of Cellulase Activity from a New Strain of Bacillus subtilis by Medium Optimization and Analysis with Various Cellulosic Substrates

Table 3

Full factorial central composite design matrix of three variables in coded units and real values (in parenthesis) with experimental and predicted response.

Run No	CMC (𝑋1) (g/L)	Peptone (𝑋2) (g/L)	Yeast extract (𝑋3) (g/L)	Enzyme activity (U/mL)
				Predicted	Observed
(1)	0 (10)	0 (5)	0 (5)	0.270	0.271
(2)	0 (10)	0 (5)	0 (5)	0.270	0.271
(3)	1 (14.76)	−1 (3.22)	1 (7.38)	0.341	0.330
(4)	−1 (5.24)	−1 (3.22)	−1 (2.62)	0.122	0.123
(5)	0 (10)	0 (5)	0 (5)	0.270	0.272
(6)	0 (10)	0 (5)	0 (5)	0.270	0.261
(7)	− α (2)	0 (5)	0 (5)	0.118	0.119
(8)	1 (14.76)	−1 (3.22)	−1 (2.62)	0.313	0.306
(9)	0 (10)	0 (5)	0 (5)	0.270	0.274
(10)	−1 (5.24)	−1 (3.22)	1 (7.38)	0.221	0.208
(11)	−1 (5.24)	1 (3.22)	1 (7.38)	0.215	0.214
(12)	0 (10)	0 (5)	0 (5)	0.270	0.271
(13)	+ α (18)	0 (5)	0 (5)	0.422	0.431
(14)	1 (14.76)	1 (6.78)	1 (7.38)	0.385	0.377
(15)	1 (14.76)	1 (6.78)	−1 (2.62)	0.364	0.371
(16)	0 (10)	− α (2.0)	0 (5)	0.269	0.283
(17)	−1 (5.24)	1 (6.78)	−1 (2.62)	0.123	0.128
(18)	0 (10)	0 (5)	+α (9.0)	0.276	0.292
(19)	0 (10)	+α (8.0)	0 (5)	0.307	0.302
(20)	0 (10)	0 (5)	− α (1.0)	0.175	0.168