Related Experiment Video
Updated: Jun 5, 2026

Scalable Step-by-Step Approach of Sustainable Bioplastic Production from Food Waste
Published on: July 18, 2025
Effects of phosphorus and nitrogen limitation on PHA production in activated sludge
Qinxue Wen1, Zhiqiang Chen, Ting Tian
1State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China. wqxshelly@263.net
Abstract:
The effects of phosphorus and nitrogen limitation on polyhydroxyalkanoate (PHA) production and accumulation by activated sludge biomass with acetate as a carbon source were investigated. Pre-selected influent carbon-phosphorus (C:P, W/W) of 100, 160, 250, 500 and 750, and carbon-nitrogen (C:N, W/W) of 20, 60, 100, 125 and 180 were applied in the phosphorus limitation experiments and the nitrogen limitation experiments, respectively. The maximum PHA accumulation up to 59% of the cell dry weight with a PHA productivity of 1.61 mg PHA/mg COD consumed was observed at the C:N 125 in the nitrogen limitation experiment. This value was much higher than that obtained in previous studies with a normal substrate feeding. The study showed that activated sludge biomass would produce more polyhydroxybutyrate than polyhydroxyvalerate under the stress of nutrient limitation, especially under phosphorus limitation conditions. The experimental result also indicated that both phosphorus and nitrogen limitation may cause sludge bulking.
Related Concept Videos
The Phosphorus Cycle
Metabolism of Chemolithotrophs
Other Stress Responses in Bacteria
Phosphorylation
During phosphorylation, protein kinases transfer the terminal phosphate group of ATP to specific amino acid side chains of substrate proteins. Serine, threonine, and tyrosine are the most commonly...
Protein Kinases and Phosphatases
Protein kinases
Many proteins in the cell are regulated by phosphorylation, the addition of a phosphate group. A family of enzymes called kinases...
Microbial Wastewater Treatment

