Abstract
Enhanced biological phosphorus removal (EBPR) selects for polyphosphate
accumulating organisms to achieve phosphate removal from wastewater. We used highresolution
community proteomics to identify key metabolic pathways in "Candidatus
Accumulibacter phosphatis"-mediated EBPR and to evaluate the contributions of co-
5 existing strains within the dominant population. Results highlight the importance of
denitrification, fatty acid cycling and the glyoxylate bypass in EBPR. Despite overall
strong similarity in protein profiles under anaerobic and aerobic conditions, fatty acid
degradation proteins were more abundant during the anaerobic phase. By
comprehensive genome-wide alignment of orthologous proteins, we uncovered strong
10 functional partitioning for enzyme variants involved in both core-metabolism and
EBPR-specific pathways among the dominant strains. These findings emphasize the
importance of genetic diversity in maintaining the stable performance of EBPR systems
and demonstrate the power of integrated cultivation-independent genomics and
proteomics for analysis of complex biotechnological systems.
