Electronic Journal of Biotechnology ISSN: 0717-3458
  © 2002 by Universidad Católica de Valparaíso -- Chile
Vol. 5 No. 2, Issue of August 15, 2002
 


Table 4.

Effect of MnSO4 concentration on the production of citric acid by mutant strain of Aspergillus niger NGGCB101 in recycling fed-batch bioreactor system.


Sampling vs. fed-batch

MnSO4 conc.

(a x 10-5M)

Peak day for maximal product formation

Total acid (g/l)

Citric acid monohydrate (g/l)

Dry cell mass (g/l)

Final pH

Sugar (g/l)

Final ferrocyanide ions conc. (ppm)

% citric acid*

Mycelial morphology

Used

Residual

Litres

%

Control

1.0

-

11.50

-

1.0 x 10-6

2.0 x 10-6

3.0 x 10-6

4.0 x 10-6

6

2

2

2

2

93.34

48.44

59.52

48.98

34.31

88.55

43.52

56.78

47.40

30.28

14.55

12.05

15.50

18.00

22.50

2.3

3.8

3.2

3.5

3.6

94.5

104.0

98.7

98.9

108.5

55.5

46.0

52.3

51.1

41.5

50.58

40.90

40.05

50.50

56.44

89.37

41.84

57.52

49.52

31.62

Small pellets

Large pellets

Mixed mycelia

Fine pellets

Fine pellets

2.0

22.50

1.0 x 10-6

2.0 x 10-6

3.0 x 10-6

4.0 x 10-6

2

2

2

2

46.55

68.95

60.04

57.62

42.34

65.55

56.78

55.02

11.55

14.06

16.65

19.90

3.8

3.1

3.3

3.4

96.5

102.0

105.5

112.5

43.5

48.0

44.5

37.5

34.52

36.50

42.55

49.98

48.23

67.59

56.90

51.21

Viscous

Viscous

Fine pellets

Fine pellets

3.0

33.50

1.0 x 10-6

2.0 x 10-6

3.0 x 10-6

4.0 x 10-6

2

2

2

2

74.67

86.46

80.90

78.74

70.98

79.86

75.54

74.24

10.00

12.50

15.75

18.90

2.6

2.4

2.5

2.5

98.6

99.5

100.0

108.5

51.4

50.5

50.0

41.5

30.54

32.00

38.04

39.50

71.98

80.26

75.54

68.42

Mixed mycelia

Mixed mycelia

Gelatinous

Gummy mass

4.0

44.50

0 x 10-6

2.0 x 10-6

3.0 x 10-6

4.0 x 10-6

2

2

2

2

98.66

134.5

106.6

94.32

92.80

128.68

98.42

90.10

9.50

12.30

13.50

14.45

2.1

1.6

1.9

2.0

94.6

95.0

103.5

110.0

45.4

55.0

46.5

40.0

22.45

22.80

24.55

25.00

83.45

96.62

89.90

86.55

Mixed mycelia

Fluffy pellets

Small pellets

Small pellets

5.0

5.50

1.0 x 10-6

2.0 x 10-6

3.0 x 10-6

4.0 x 10-6

3

3

3

3

79.34

95.90

92.22

89.56

78.25

91.20

87.52

85.40

8.00

9.50

10.50

12.40

2.4

2.2

2.5

2.6

120.5

115.0

104.5

100.5

29.5

35.0

45.5

49.5

20.80

21.34

24.05

24.52

72.42

66.78

76.98

71.05

Mixed mycelia

Fine pellets

Fine pellets

Fine pellets


Initial sugar concentration 150 g/l, initial pH 6.0, aeration rate 1.0l/l/min, incubation temperature 30C, ferrocyanide ion concentration 200 ppm. Total volume of the fermentation medium was kept constant i.e., 9-L (60 %) throughout for all the treatments. *On the basis of sugar used, All the results are sum mean of three parallel replicates.

Supported by UNESCO / MIRCEN network