Figure 6. Growth and PHB accumulation of R. sphaeroides N20 on optimal medium contained acetate (carbon source), 4.0 g/l; (NH₄)₂SO₄ (nitrogen source), 0.02 g/l; KH₂PO₄, 0.1 g/l and K₂HPO₄, 0.1 g/l; at 37ºC, under controlled agitation and aeration rate at 150 rpm and aeration rate at 1.0 vvm, at pH (7.0).