Related Experiment Video
Updated: Feb 17, 2026
07:20
Bioprospecting of Extremophilic Microorganisms to Address Environmental Pollution
Published on: December 30, 2021
4.3K
Highly Effective Polyphosphate Synthesis, Phosphate Removal, and Concentration Using Engineered Environmental
Xin Wang1, Xiaomeng Wang1, Kaimin Hui2
1State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University , Nanjing 210046, P. R. China.
Environmental Science & Technology
|December 1, 2017
Summary
Engineered bacteria efficiently produce polyphosphate (polyP) for wastewater phosphate removal. This strategy enables high polyP accumulation and effective phosphorus recovery from wastewater.
Area of Science:
- Environmental Biotechnology
- Microbial Engineering
- Wastewater Treatment
Background:
- Microbial polyphosphate (polyP) production is crucial for phosphate removal from wastewater.
- Engineering environmental bacteria for efficient polyP synthesis has been challenging.
- Polyphosphate kinase (PPK1) is a key enzyme in polyP biosynthesis.
Purpose of the Study:
- To develop a simple and effective strategy for high intracellular polyP accumulation in environmental bacteria.
- To engineer Citrobacter freundii for enhanced polyphosphate production and phosphate removal.
- To evaluate the potential for phosphorus recovery from wastewater using engineered bacteria.
Main Methods:
- Developed a medium-copy plasmid-based overexpression strategy for the polyphosphate kinase (PPK1) gene.
- Engineered Citrobacter freundii to overexpress PPK1, creating a polyP-accumulating strain (CPP).
- Utilized a bench-scale sequence batch membrane reactor for one-step phosphate removal from synthetic wastewater.
Main Results:
- Engineered Citrobacter freundii (CPP) achieved high intracellular polyP content, up to 12.7% of dry weight.
- Negligible metabolic burden ensured good biomass yield for the engineered CPP.
- CPP demonstrated efficient removal of phosphate (Pi) from synthetic municipal wastewater, with most phosphorus recovered as concentrated Pi.
Conclusions:
- Solo medium-copy plasmid-based PPK1 overexpression is a viable general strategy for engineering environmental bacteria for high polyP production.
- This approach facilitates biotechnological research requiring significant intracellular polyP.
- The engineered bacteria offer a promising solution for efficient wastewater phosphate removal and phosphorus enrichment.
