Optimization of lipids’ ultrasonic extraction and production from Chlorella sp. using response-surface methodology

Table 5 Student test results for lipids production

	Coefficient	SD of coefficient	t	p-value
Constant	−32.738	93.242	− 0.351	0.729
Block	−0.828	2.336	−0.354	0.727
[NaNO₃]	21.260	5.592	3.802	0.001^b
[NaNO₃]²	−8.525	2.413	−3.533	0.002^b
[NaCl]	0.111	1.827	0.061	0.952
[NaCl]²	0.008	0.038	0.207	0.838
Light intensity	0.371	0.751	0.494	0.627
Light intensity²	−0.001	0.002	−0.389	0.701
[NaNO₃] × [NaCl]	0.048	0.087	0.547	0.590
[NaNO₃] × Light intensity	−0.028	0.008	−3.453	0.003^b
[NaCl] × Light intensity	−0.002	0.001	−2.247	0.037^a

ISSN: 1476-511X