Occurrence and Role of Poly-Hydroxy-Alkanoate in the Cyanobacterium Oscillatoria Limosa

Abstract

The marine filamentous cyanobacterium Oscillatoria limosa accumulated the reserve compound poly-hydroxy-alkan oate. The intracellular amount of this polymer increased during logarithmic growth and reached a maximum in the stationary phase. Inoculation of stationary cells in fresh medium resulted in a dramatic decrease of PHA during the lag phase, after which its accumulation resumed. The cellular content of PHA did not change significantly during the dark, nei ther under oxic nor anoxic conditions. These resul ts hinted to an exclusive role of PHA as carbon reserve, whereas the energy reserve compound in this organism was glycogen. Preliminary analysis indicated that the PHA might be composed of 3-hydroxyvaleric acid.