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Table 5 Polymer composition, thermal properties, and thermal degradation of PHA extracted from B. thuringiensis after each cycle of the cyclic fed-batch fermentation compared with commercial PHB, and PHBV

From: Optimization of cultivation medium and cyclic fed-batch fermentation strategy for enhanced polyhydroxyalkanoate production by Bacillus thuringiensis using a glucose-rich hydrolyzate

 

Polymer composition (mol %)

Degradation temperature (°C)

Thermal properties

HB

HV

HHx

T5%

Tmax

Tg (°C)

Tm1 (°C)

Tm2 (°C)

∆Hm (J g−1)

Tc (°C)

∆Hc (J g−1)

Xc (%)

Batch fermentation

82.13

17.87

–

217.15

286.81

4.98

155.4

166.64

85.59

78.07

62.61

59

CFBF cycle 1

77.45

22.55

–

222.52

286.87

4.95

149.89

160.77

83.93

83.69

65.89

57

CFBF cycle 2

54.56

42.80

2.64

248.60

289.96

4.71

147.17

158.35

59.76

115.18

54.96

40

CFBF cycle 3

52.48

43.78

3.74

253

290.66

4.65

143.77

154.53

55.77

118.54

53.50

38

CFBF cycle 4

48.43

46.39

5.18

275.54

292.21

4.60

129.53

140.82

49.77

122.14

46.53

34

Commercial PHB

89.81

10.19

–

269.66

286.77

5.02

171.65

174.69

90.35

75.5

63.92

62

Commercial PHBV

43.35

56.65

–

264.04

288.32

4.85

138.22

146.94

60.55

113.17

58.06

41