Accumulation of polyhydroxyalkanoates (PHAs) in activated sludge under nitrogen limitation conditions. Part II. Estimation of bacterial diversity in activated sludge and analysis of a type of accumulated polyhydroxyalkanoates
Community diversity of the activated sludge and the type of accumulated PHAs were investigated in this study. Fed-batch culture was carried out using medium culture containing sodium acetate as a carbon source. A factor triggering PHAs synthesis was a lack of nitrogen. The medium culture containing ammonium was periodically fed into bacterial culture for 6 hours each day of the experiment. Genetic analysis of the bacterial community was performed using 16S and 23S rRNA Intergeneric Spacer Region. The obtained results showed that the dominant belonged to the Betaproteobacteria class. In this study, the Time of flight - Secondary Ion Mass Spectrometry was used. This method revealed that the cells of the microorganisms contained mainly monomer units of 3-hydroxybutryric acid. The content of P(3HB) in dry weight accounted for 51% between 72nd and 120th hour of the experiment.