Advances in resource exploration and metabolic mechanism of denitrifying phosphorus-accumulating organisms in wastewater from a single-cell perspective

Abstract:

Amidst the escalating issues of water eutrophication and water resource scarcity, the development of high-efficiency wastewater treatment technologies has become increasingly imperative. Traditional nitrogen and phosphorus removal processes face challenges in achieving efficient simultaneous elimination of nitrogen and phosphorus due to the disparities in sludge age and the competition for carbon sources among microorganisms. Denitrifying phosphorus-accumulating organisms (DPAOs) possess the capability to remove both nitrogen and phosphorus, demonstrating significant potential in wastewater treatment. However, population-level studies often overlook cellular heterogeneity, leading to an inadequate understanding of the nitrogen and phosphorus removal mechanisms of DPAOs. Moreover, the “traditional culture-first, screen-second” method yields a limited number of efficient DPAO strains, the stability and adaptability of which face challenges in actual wastewater treatment environments. Single-cell analysis technologies provide new perspectives for a deeper understanding of microbial ecological niches and metabolic mechanisms. Coupling non-destructive single-cell phenotypic identification technologies, such as single-cell Raman spectroscopy (SCRS), with the culture method paves new avenues for the exploration of DPAO strains. This review summarizes the research status and progress in the exploration of DPAO strain resources and their metabolic mechanisms, focusing on the potential of single-cell technologies in revealing the mechanisms of nitrogen and phosphorus removal by DPAOs and in the exploration of DPAO resources. The aim is to provide a new theoretical foundation and technical support for the research and application of DPAOs, thereby promoting the development of efficient wastewater treatment technologies.