Abstract
Despite recent evidence from full-scale plants suggesting that Candidatus Accumulibacter may be capable of using amino acids, this metabolic trait has never been confirmed in a bioreactor experiment. Here we show that an enriched culture of Ca. Accumulibacter clade IIF strain SCELSE-1 could metabolize 11 of 20 α-amino acids, with aspartate, glutamate, asparagine, and glutamine resulting in the highest phosphorus removal. The anaerobic uptake of aspartate and glutamate was achieved through a glutamate/aspartate-proton symporter fully powered by the proton motive force (PMF). Under anaerobic conditions aspartate was deaminized and routed into core carbon metabolic pathways to form polyhydroxyalkanoates (PHA). The lack of genes encoding NADH dependent isocitrate dehydrogenase in the Ca. Accumulibacter genome resulted in a kinetic barrier for glutamate to be channelled to the TCA cycle. Glutamate was stored as glutamate polymer. When amino acids (aspartate or glutamate) and acetate were supplied together, Ca. Accumulibacter took up both carbon sources simultaneously, with the uptake rate of each carbon source largely preserved. Overall energy savings (up to 17%) were achieved under mixed carbon scenarios, due to the ability of Ca. Accumulibacter to rearrange its anaerobic carbon metabolism based on the reducing power, PMF and ATP balance.
Originalsprog | Engelsk |
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Tidsskrift | Environmental Science and Technology |
Vol/bind | 54 |
Udgave nummer | 4 |
Sider (fra-til) | 2448-2458 |
Antal sider | 11 |
ISSN | 0013-936X |
DOI | |
Status | Udgivet - 18 feb. 2020 |
Bibliografisk note
Funding Information:This research was supported by the Singapore National Research Foundation and the Ministry of Education under the Research Centre of Excellence Programme, and by a research grant from the National Research Foundation under its Environment and Water Industry Programme (project number 1102-IRIS-10-02), administered by Public Utilities Board, Singapore?s national water agency. Dr. Guanglei Qiu acknowledges the support of National Natural Science Foundation of China (No. 51808297) and the Fundamental Research Funds for the Central Universities, China (No. 2019ZD21).
Funding Information:
This research was supported by the Singapore National Research Foundation and the Ministry of Education under the Research Centre of Excellence Programme, and by a research grant from the National Research Foundation under its Environment and Water Industry Programme (project number 1102–IRIS–10–02), administered by Public Utilities Board, Singapore’s national water agency. Dr. Guanglei Qiu acknowledges the support of National Natural Science Foundation of China (No. 51808297) and the Fundamental Research Funds for the Central Universities, China (No. 2019ZD21).
Publisher Copyright:
© 2019 American Chemical Society.