Table 2 Analysis of variance (ANOVA) and regression statistics for the experimental results of Plackett Burman design of melanin production by S. djakartensis NSS-3

Model

3420.80

17

201.22

122.51

0.0081*

99.19

Incubation period (A)

674.99

1

674.99

410.94

0.0024*

99.76

pH (B)

129.51

1

129.51

78.85

0.0124*

98.76

Temperature (C)

303.13

1

303.13

184.55

0.0054*

99.46

Inoculum size (D)

1.69

1

1.69

1.03

0.4174*

58.26

Agitation speed (E)

4.12

1

4.12

2.51

0.2541*

74.59

Yeast extract (F)

74.58

1

74.58

45.40

0.0213*

97.87

Peptone (G)

34.02

1

34.02

20.71

0.0450*

95.5

Peptic digest (H)

117.63

1

117.63

71.62

0.0137*

98.63

L-tyrosine (J)

713.46

1

713.46

434.37

0.0023*

99.77

Copper sulphate (K)

36.45

1

36.45

22.19

0.0422*

95.78

Ferric ammonium citrate (L)

389.38

1

389.38

237.06

0.0042*

99.58

Dipotassium phosphate (M)

51.08

1

51.08

31.10

0.0307*

96.93

Sodium thiosulphate (N)

1.49

1

1.49

0.9056

0.4417*

55.83

Residual

3.29

2

1.64

Cor Total

3424.09

19

R-Squared

0.9990

Std. Dev

1.28

Mean

35.35

Adjusted R-Squared

0.9909

C.V. %

3.63

Predicted R-Squared

0.8508

Adeq Precision

33.1686