Mixed culture polyhydroxyalkanoates production from sugar molasses: The use of a 2-stage CSTR system for culture selection

Mixed culture polyhydroxyalkanoate (PHA) production from volatile fatty acid (VFA)-rich streams: Effect of substrate composition and feeding regime on PHA productivity, composition and properties

“…d −qS and qP are the average specific rates of substrate uptake and PHA storage, in Cmol VFA/Cmol X h and Cmol PHA/Cmol X h, respectively, calculated for the entire batch. of substrate uptake and PHA storage on substrate concentration has been reported for the enrichment reactor operating cycles (Albuquerque et al, 2010a,b), for which an affinity constant (k S ) of about 18.5 Cmmol VFA/L was reported (Albuquerque et al, 2010b). Fig.…”

Link between microbial composition and carbon substrate-uptake preferences in a PHA-storing community

“…A similar substrate-uptake pattern was observed during the pulse-wise feeding batch accumulation assay (Figure 2 and Table 3). Though the low uptake rates of propionate and valerate could be associated with limiting concentrations of these carbon sources (as suggested in Albuquerque et al (2010b)), the same argument cannot justify the lower uptake rate of acetate, because this was the most abundant carbon compound (Table 2). Furthermore, a sudden increase of the acetate-and propionate-uptake rates was observed once the remaining VFA substrates were depleted (Figures 1c and 2), suggesting that the lower acetate-and propionate-uptake rates were not associated to inhibiting concentrations of these carbon sources but that, while present, other carbon sources were preferred in detriment of acetate and propionate.…”

“…PHAs were determined by gas chromatography using the method described in Albuquerque et al (2010b). Hydroxybutyrate (HB) and hydroxyvalerate (HV) concentrations were calculated using the P(HB-HV) (88%/12%) (Sigma) standards and corrected using an heptadecane internal standard.…”

Survival of the fastest: Selective removal of the side population for enhanced PHA production in a mixed substrate enrichment

“…Nonetheless, when using real wastewater the experimental results indicated that PHA production is primarily associated with the VFA fraction of the wastewater (Coats et al, 2007;Bengtsson et al, 2008;Beccari et al, 2009;Albuquerque et al, 2010;Morgan-Sagastume et al, 2010;Jiang et al, 2012;Tamis et al, 2014a;Morgan-Sagastume et al, 2014, 2015Korkakaki et al, 2016). This correlation is based on the fact that the VFA carbon fraction serves as a PHA precursor and efficiently enriches for a PHA accumulating community.…”