Poly(hydroxyalkanoate) in cyanobacteria: an overview

In this paper an overview is given on the occurrence of poly(hydroxyalkanoate) (PHA) in cyanobacteria and its possible role as a putative reserve compound. Comparisons are made with the function of other storage compounds that occur in cyanobacteria. For the cyanobacteria Oscillatoria limosa and Gloeothece sp. PCC 6909, some experimental data on the accumulation and mobilization of PHA are presented. O. limosa presumably contains poly(hydroxyvalerate) (PHV), whereas in Gloeothece poly(hydroxybutyrate) (PHB) was detected. Both species accumulated PHA to 6–9% of the dry weight. In Gloeothece PHB accumulation was stimulated by the addition of acetate but in O. limosa this was not the case. PHA was not involved in dark metabolism in either of the strains.