TY - JOUR
T1 - Metabolic Response of “Candidatus Accumulibacter Phosphatis” Clade II C to Changes in Influent P/C Ratio
AU - Welles, Laurens
AU - Abbas, Ben
AU - Sorokin, Dmitry
AU - Lopez Vazquez, Carlos
AU - Hooijmans, C. M.
AU - van Loosdrecht, Mark
AU - Brdanovic, D.
PY - 2017/1/5
Y1 - 2017/1/5
N2 - The objective of this study was to investigate the ability of a culture highly enriched with the polyphosphate-accumulating organism, “Candidatus Accumulibacter phosphatis” clade IIC, to adjust their metabolism to different phosphate availabilities. For this purpose the biomass was cultivated in a sequencing batch reactor with acetate and exposed to different phosphate/carbon influent ratios during six experimental phases. Activity tests were conducted to determine the anaerobic kinetic and stoichiometric parameters as well as the composition of the microbial community. Increasing influent phosphate concentrations led to increased poly-phosphate content and decreased glycogen content of the biomass. In response to higher biomass poly-phosphate content, the biomass showed higher specific phosphate release rates. Together with the phosphate release rates, acetate uptake rates also increased up to an optimal poly-phosphate/glycogen ratio of 0.3 P-mol/C-mol. At higher poly-phosphate/glycogen ratios (obtained at influent P/C ratios above 0.051 P-mol/C-mol), the acetate uptake rates started to decrease. The stoichiometry of the anaerobic conversions clearly demonstrated a metabolic shift from a glycogen dominated to a poly-phosphate dominated metabolism as the biomass poly-phosphate content increased. FISH and DGGE analyses confirmed that no significant changes occurred in the microbial community, suggesting that the changes in the biomass activity were due to different metabolic behavior, allowing the organisms to proliferate under conditions with fluctuating phosphate levels.
AB - The objective of this study was to investigate the ability of a culture highly enriched with the polyphosphate-accumulating organism, “Candidatus Accumulibacter phosphatis” clade IIC, to adjust their metabolism to different phosphate availabilities. For this purpose the biomass was cultivated in a sequencing batch reactor with acetate and exposed to different phosphate/carbon influent ratios during six experimental phases. Activity tests were conducted to determine the anaerobic kinetic and stoichiometric parameters as well as the composition of the microbial community. Increasing influent phosphate concentrations led to increased poly-phosphate content and decreased glycogen content of the biomass. In response to higher biomass poly-phosphate content, the biomass showed higher specific phosphate release rates. Together with the phosphate release rates, acetate uptake rates also increased up to an optimal poly-phosphate/glycogen ratio of 0.3 P-mol/C-mol. At higher poly-phosphate/glycogen ratios (obtained at influent P/C ratios above 0.051 P-mol/C-mol), the acetate uptake rates started to decrease. The stoichiometry of the anaerobic conversions clearly demonstrated a metabolic shift from a glycogen dominated to a poly-phosphate dominated metabolism as the biomass poly-phosphate content increased. FISH and DGGE analyses confirmed that no significant changes occurred in the microbial community, suggesting that the changes in the biomass activity were due to different metabolic behavior, allowing the organisms to proliferate under conditions with fluctuating phosphate levels.
KW - polyphosphate-accumulatingorganisms (PAO)
KW - glycogen-accumulatingorganisms (GAO)
KW - phosphate limitation
KW - metabolic response
KW - microbial population dynamics
KW - OA-Fund TU Delft
UR - http://resolver.tudelft.nl/uuid:d092baee-2c0d-4b31-8e8d-d253911bdeb3
U2 - 10.3389/fmicb.2016.02121
DO - 10.3389/fmicb.2016.02121
M3 - Article
SN - 1664-302X
VL - 7
JO - Frontiers in Microbiology
JF - Frontiers in Microbiology
M1 - 2121
ER -