Table 6 Analysis of variance (ANOVA) for the experimental results in the central composite design quadratic model and response regarding to total carotenoid production by strain MBLA0099. A: pH; B; yeast extract; C; NaCl; D; inoculum volume; E; incubation time. df means degree of freedom

Model

20

0.00452

-0.424

0.394366

78.4

0

A

1

0.0027

-0.0017

0.180964

719.55

0***

B

1

+ 0.0669

0.000038

0.15

0.699

C

1

+ 0.02525

0.000927

3.69

0.065

D

1

+ 0.00053

0.003047

12.12

0.002**

E

1

-0.0172

0.015377

61.14

0***

A²

1

0.0101

+ 0.00025

0.000001

0

0.956

B²

1

-0.005743

0.01519

60.4

0***

C²

1

-0.000698

0.003807

15.14

0.001**

D²

1

-0.000542

0.000298

1.18

0.286

E²

1

-0.00136

0.000368

1.46

0.237

AB

1

0.0028

+ 0.001306

0.001677

6.67

0.016*

AC

1

+ 0.000194

0.000153

0.61

0.443

AD

1

+ 0.001

0.001459

5.8

0.023*

AE

1

+ 0.004601

0.013717

54.54

0***

BC

1

+ 0.000225

0.001244

4.95

0.035*

BD

1

+ 0.000389

0.001335

5.31

0.029*

BE

1

+ 0.000632

0.00157

6.24

0.019*

CD

1

-0.000131

0.000621

2.47

0.128

CE

1

+ 0.000171

0.000475

1.89

0.181

DE

1

+ 0.000034

0.000007

0.03

0.87