Table 2. The effect of C/N ratio on PHB accumulation by Rhodobacter sphaeroides N20 after 60 hrs cultivation in GA medium containing acetate, (NH₄)₂SO₄ as carbon and nitrogen source, respectively at 37ºC, 150 rpm, pH 7.0.

C/N ratio
(mole of C/mole of N)

Maximum growth

PHB

DCW
(g/l)

Conc.
(g/l)

content
(% of DCW)

12:1

7.80 ± 0.09

3.67 ± 0.22

47.0

6:1

8.11 ± 0.12

5.94 ± 0.11

73.2

3:1

6.63 ± 0.15

1.85 ± 0.14

27.9

0.3:1

5.98 ± 0.21

0.75 ± 0.19

12.6

0.15:1

5.44 ± 0.10

0.36 ± 0.08

6.7