Bioenergetic Models for Acetate and Phosphate Transport in Bacteria Important in Enhanced Biological Phosphorus Removal

Burow, Luke C., Mabbett, Amanda N., McEwan, Alastair G., Bond, Philip L. and Blackall, Linda L. (2008) Bioenergetic Models for Acetate and Phosphate Transport in Bacteria Important in Enhanced Biological Phosphorus Removal. Environmental Microbiology, 10 1: 87-98. doi:10.1111/j.1462-2920.2007.01432.x


Author Burow, Luke C.
Mabbett, Amanda N.
McEwan, Alastair G.
Bond, Philip L.
Blackall, Linda L.
Title Bioenergetic Models for Acetate and Phosphate Transport in Bacteria Important in Enhanced Biological Phosphorus Removal
Journal name Environmental Microbiology   Check publisher's open access policy
ISSN 1462-2912
Publication date 2008
Sub-type Article (original research)
DOI 10.1111/j.1462-2920.2007.01432.x
Volume 10
Issue 1
Start page 87
End page 98
Total pages 12
Place of publication Oxford
Publisher Blackwell Science
Collection year 1970
Language eng
Formatted abstract
Most of our understanding of the physiology of microorganisms is the result of investigations in pure culture. However, in order to understand complex environmental processes, there is a need to investigate mixed microbial communities. This is true for enhanced biological phosphorus removal (EBPR), an environmental process that results in the enrichment of the polyphosphate-accumulating organism Accumulibacter spp. and the glycogen non-polyphosphate accumulating organism Defluviicoccus spp. We investigated acetate and inorganic phosphate (Pi) uptake in enrichments of Accumulibacter spp. and acetate uptake in enrichments of Defluviicoccus spp. For both enrichments, anaerobic acetate uptake assays in the presence of the protonophore, carbonyl cyanide m-chlorophenylhydrazone (CCCP) or the membrane potential (Δψ) uncoupler valinomycin, indicated that acetate is likely to be taken up by a permease-mediated process driven by the Δψ. Further investigation with the sodium ionophore monensin suggested that anaerobic acetate uptake by Defluviicoccus spp. may in part be dependent on a sodium potential. Results of this study also suggest that Accumulibacter spp. generate a proton motive force (pmf or Δp) for anaerobic acetate uptake by efflux of protons in symport with Pi through an inorganic phosphate transport (Pit) system. In contrast, we suggest that the anaerobic Δp in Defluviicoccus spp. is generated by an efflux of protons across the cell membrane by the fumarate respiratory system, or by extrusion of sodium ions via decarboxylation of methylmalonyl-CoA. Aerobic Pi uptake by the Accumulibacter spp. enrichment was strongly inhibited in the presence of an ATPase inhibitor, suggesting that the phosphate-specific transport (Pst) system is important even under relatively high concentrations of Pi. Acetate permease activity in these microorganisms may play an important role in the competition for acetate in the often acetate-limited EBPR process. Activity of a high-velocity Pst system in Accumulibacter spp. may further explain its ability to compete strongly in EBPR.
Keyword Glycogen-accumulating Organisms
Activated-sludge Systems
Proton Motive Force
Water Treatment Processes
Escherichia Coli
Anaerobic Conditions
Fumarate-reductase
Metabolic Model
Carbon-sources
Scale
Q-Index Code C1
Q-Index Status Provisional Code
Institutional Status UQ

Document type: Journal Article
Sub-type: Article (original research)
Collections: Excellence in Research Australia (ERA) - Collection
Advanced Water Management Centre Publications
 
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Citation counts: TR Web of Science Citation Count  Cited 22 times in Thomson Reuters Web of Science Article | Citations
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Created: Thu, 27 Mar 2008, 16:00:49 EST by Suzanne Read on behalf of Advanced Water Management Centre