Feast famine enrichment on octanoate with activated sludge - Genome sequencing and assembly

The aim of this research is to study which enrichment strategies result in a community with a high mcl-PHA storage capacity.To this end, sequencing batch reactors (SBRs) were operated with octanoate as substrate. Analysis of the PHA metabolic pathways revealed that the production of mcl-PHA requires less oxygen respiration than scl-PHA production. This resulted in the hypothesis that mcl-PHA production has a competitive advantage in an oxygen limited environment. Therefore, the dissolved oxygen concentration was varied to understand and modify the enrichment process in terms of PHA content and composition. In addition, the pH of the SBRs was varied to study the effect of the toxicity of undissociated octanoic acid. For every operational steady state, the performance of the enrichments was characterized, including the maximum PHA storage capacity by means of accumulation experiments.