Enhanced Biological Phosphorus Removal (EBPR) is used worldwide to remove phosphorus from both municipal and industrial wastewaters, protecting our surface waters from excessive algal growth and the associated long-term degradation of water quality. Despite its successful use, very little is known about the naturally occurring microorganisms that carry out EBPR. These microorganisms have eluded researchers for over 30 years – they cannot be grown in pure culture. One major group of EBPR organisms was recently identified by cultivation-independent techniques and was named Accumulibacter phosphatis. The goal of this research is to learn more about the mechanism responsible for EBPR and the ecology of Accumulibacter.

Community and population ecology of Accumulibacter - We have identified at least five different species-like groups of Accumulibacter in lab and full-scale EBPR systems. The relative abundance of these different groups can be determined using a real-time quantitative PCR technique we have developed to target the polyphosphate kinase gene. This genetic marker allows for detection of individual groups for comparative purposes across time and space. We are currently investigating the ecology of these species-like groups to determine if their differences account for varying performance in full-scale EBPR systems. We also were recently awarded up to twelve 454-FLX (pyrosequencing) runs to explore community and population dynamics in EBPR communities, through the Joint Genome Institute.

Postdocs:

Shaomei He



Collaborators:

Philip Hugenholtz, DOE Joint Genome Institute

Snow Brook Peterson, University of Wisconsin-Madison

April Gu, Northeastern University

Nancy Love, Virginia Tech

Charles Bott, Virginia Military Institute

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Genome-enabled study of metabolism - The metagenome of a highly enriched activated sludge from our bioreactor operating in Madison, Wisconsin, was sequenced at JGI in 2004. A complete reconstruction of the EBPR metabolism was possible based on established metabolic models and the genome sequence information. The study provided a much needed blueprint for a systems-level understanding of EBPR. In follow-up studies we are now investigating factors affecting gene expression in Accumulibacter using oligonucleotide probe microarrays, whole (meta)transcriptome sequencing, and (meta)proteomics.



Postdocs:

Shaomei He



Students:


Jason Flowers



Collaborators:

Philip Hugenholtz, DOE Joint Genome Institute

Vincent Martin, Concordia University


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