Accumulating PHAs is a natural way for bacteria to store carbon
and energy when environmental conditions are disturbed. In laboratory
conditions these polyesters are accumulated when bacterial
growth is limited by depletion of nitrogen, phosphorous or
oxygen and an excess amount of a carbon source is still present
(Anderson and Dawes, 1990; Ciesielski et al., 2010).
PHAs are accumulated in intracellular granules inside the cells.
In Cupriavidus necator (formerly Ralstonia eutropha), 8-13 granules