Screening and characterizing a denitrifying phosphorus-accumulating bacterium isolated from a circular plug-flow...

Area of Science:

• Environmental microbiology
• Wastewater treatment technologies
• Bioremediation

Background:

• Denitrifying phosphorus-accumulating organisms (DNPAO) are crucial for simultaneous nitrogen and phosphorus removal in wastewater.
• Existing treatment methods face challenges in efficiently removing both pollutants concurrently.

Purpose of the Study:

• To isolate and characterize a novel DNPAO from activated sludge.
• To evaluate the efficiency of the isolated organism in removing nitrogen and phosphorus.
• To understand the metabolic capabilities of the DNPAO regarding electron acceptors.

Main Methods:

• Isolation of DNPAO from activated sludge using a patented circular plug-flow reactor.
• Identification of the isolate (C-17) as Pseudomonas sp. using 16S rRNA sequencing and phenotypic analysis.
• Experimental evaluation of nitrogen and phosphorus removal efficiencies and phosphorus release ratios.

Main Results:

• Pseudomonas C-17 demonstrated high removal efficiencies: 75% for [Formula: see text] and 87% for NO3-N.
• Phosphorus release ratios were significant: 25.0 mg [Formula: see text] (with anabolism) and 26.8 mg [Formula: see text] (without anabolism).
• The organism effectively utilizes oxygen, nitrate, and nitrite as electron acceptors.

Conclusions:

• Pseudomonas C-17 exhibits a strong capacity for phosphorus release, crucial for DNPAO function.
• Accurate evaluation of phosphorus uptake requires considering metabolic consumption.
• This DNPAO presents a viable biological solution for enhanced nutrient removal in wastewater treatment.