Table 3. Kinetic parameters of ethanol production from the sweet sorghum juice with yeast extract supplementation in repeated-batch fermentation.

Batch number

Parameters (mean ± SD)*

Cell concentration
(cells ml^-1) at

P^A
(g l^-1)

P^B
(g l^-1)

Q_p
(g l^-1h^-1)

Y_p/s
(g g^-1)

t^C
(hrs)

Initial

t^C
(hrs)

1

129.48 ± 2.96^d

129.48 ± 2.96^d

4.01 ± 0.09^e

0.48 ± 0.02^a

32

8.24 x 10⁷

3.28 x 10⁸

2

107.80 ± 0.39^b,c

39.70 ± 0.39^a

0.62 ± 0.01^a,b,c

0.47 ± 0.01^a

64

1.87 x 10⁸

1.72 x 10⁸

3

108.90 ± 3.26^c

51.67 ± 3.26^c

0.72 ± 0.10^b,c,d

0.46 ± 0.01^a

72

8.60 x 10⁷

8.80 x 10⁷

4

109.02 ± 0.39^c

52.65 ± 0.39^c

0.82 ± 0.01^d

0.49 ± 0.02^a

64

7.85 x 10⁷

9.10 x 10⁷

5

101.44 ± 3.09^a

43.81 ± 3.09^a,b

0.61 ± 0.08^a,b

0.48 ± 0.04^a

72

5.04 x 10⁷

4.50 x 10⁷

6

103.37 ± 3.35^a,b

45.35 ± 3.35^b

0.63 ± 0.05^a,b,c

0.46 ± 0.03^a

72

2.79 x 10⁷

2.92 x 10⁷

7

109.53 ± 3.58^c

52.61 ± 3.58^c

0.73 ± 0.05^c,d

0.49 ± 0.02^a

72

2.91 x 10⁷

3.60 x 10⁷

8

102.46 ± 2.68^a

44.76 ± 2.68^b

0.53 ± 0.03^a

0.46 ± 0.01^a

72

1.78 x 10⁷

2.02 x 10⁷