Effects of environmental conditions on cell growth and poly-β-hydroxybutyrate accumulation in Alcaligenes eutrophus

Influences of the control of glucose and oxygen concentrations on cell growth and poly- beta -hydroxybutyrate (PHB) accumulation in Alcaligenes eutrophus were studied. Glucose affects both biosynthesis and glycolysis directly and the other pathways indirectly. PHB accumulation could also be stimulated under oxygen limitation conditions, but the final PHB content within the cells was less than in the case of nitrogen limitation. When the culture was shifted from the PHB accumulation state to balanced growth conditions, PHB degradation occurred in the cells. The cell growth was inhibited by high PHB content within the cells.