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

Influences of the control of glucose and oxygen concentrations on cell grow th and poly-beta-hydroxybutyrate (PHB) accumulation in Alcaligenes eutrophu s were studied. Glucose affects both biosynthesis and glycolysis directly a nd the other pathways indirectly. PHB accumulation could also be stimulated under oxygen limitation conditions, but the final PHB content within the c ells 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 P HB content within the cells.