Optimization of Culture Conditions for Production of the Anti-Leukemic Glutaminase Free L-Asparaginase by Newly Isolated Streptomyces olivaceus NEAE-119 Using Response Surface Methodology

Table 4

Statistical analysis of Plackett-Burman design showing coefficient values, main effect, -test, values, and confidence level (%) for each variable affecting L-asparaginase production and analysis of variance.

(a)

Variables	Coefficients	Main effect	-Stat	value	Confidence level (%)
Intercept	16.196	32.392	20.4659	0.0000	99.996
Temperature (°C)	2.642	5.283	3.3382	0.0289	97.111
pH	−0.457	−0.914	−0.5776	0.5945	40.549
Incubation time (days)	−3.763	−7.527	−4.7554	0.0089	99.106
Inoculum size (%, v/v)	0.564	1.127	0.7123	0.5156	48.436
Inoculum age (h)	3.486	6.972	4.4049	0.0116	98.835
Agitation speed (rpm)	5.555	11.110	7.0197	0.0022	99.783
Dextrose (g/L)	1.543	3.086	1.9496	0.1230	87.699
Starch (g/L)	0.529	1.059	0.6691	0.5401	45.991
L-asparagine (g/L)	0.780	1.560	0.9856	0.3801	61.989
KNO3 (g/L)	−2.572	−5.144	−3.2499	0.0314	96.862
Yeast extract (g/L)	−1.351	−2.702	−1.7070	0.1630	83.700
K2HPO4 (g/L)	−0.962	−1.924	−1.2159	0.2909	70.912
MgSO4·7H2O (g/L)	−2.784	−5.568	−3.5180	0.0245	97.551
NaCl (g/L)	−4.560	−9.121	−5.7627	0.0045	99.550
FeSO4·7H2O (g/L)	−3.456	−6.912	−4.3669	0.0120	98.800

(b)

	Analysis of variance (ANOVA)
	df	SS	MS	-test	Significance ( value)
Regression	15	2356.0614	157.0707	12.5404	0.01262
Residual	4	50.100594	12.52514
Total	19	2406.1620

t: Student's test; : corresponding level of significance; df: degree of freedom; SS: sum of squares; MS: mean sum of squares; : Fishers's function; Significance : corresponding level of significance.
Multiple 0.9895, square 0.9791, and adjusted square 0.9010.