Biomaterial Database

Effects of ions and phosphates on alkaline phosphatase activity in aerobic activated sludge system. 2010

Chunsheng Xie, and Rongjie Lu, and Yan Huang, and Qian Wang, and Xinhua Xu

Department of Environmental Engineering, Zhejiang University, Hangzhou 310027, People's Republic of China.

The influence of metal ions, anions, ortho-phosphate, polyphosphate and organic phosphorus on the activity and kinetics of alkaline phosphatase in aerobic activated sludge taken from a local municipal wastewater treatment plant was investigated. Results suggested that there were three impact models of heavy metals on alkaline phosphatase activity (APA) and most inorganic anions were relatively innocuous at concentrations from 0 to 5.0mM. However, phosphorus especially pyrophosphate had an inhibitory effect on APA, since the residual activity of alkaline phosphatase dramatically decreased to 34.8% of the control at the pyrophosphate concentration of 5.0mM. The inhibition of Cu(2+) on alkaline phosphatase was described satisfactorily by an uncompetitive type at low concentrations, but a mixed of noncompetitive-uncompetitive type at high concentrations. The inhibition of ortho-phosphate was found to be of the competitive type. V(max)/K(m) ratio is a good indicator for the catalytic efficiency of alkaline phosphatases in wastewater.

UI	MeSH Term	Description	Entries
D007477	Ions	An atom or group of atoms that have a positive or negative electric charge due to a gain (negative charge) or loss (positive charge) of one or more electrons. Atoms with a positive charge are known as CATIONS; those with a negative charge are ANIONS.
D007700	Kinetics	The rate dynamics in chemical or physical systems.
D010710	Phosphates	Inorganic salts of phosphoric acid.	Inorganic Phosphate,Phosphates, Inorganic,Inorganic Phosphates,Orthophosphate,Phosphate,Phosphate, Inorganic
D000332	Aerobiosis	Life or metabolic reactions occurring in an environment containing oxygen.	Aerobioses
D000469	Alkaline Phosphatase	An enzyme that catalyzes the conversion of an orthophosphoric monoester and water to an alcohol and orthophosphate. EC 3.1.3.1.
D012722	Sewage	Refuse liquid or waste matter carried off by sewers.	Sludge,Sludge Flocs
D019216	Metals, Heavy	Metals with high specific gravity, typically larger than 5. They have complex spectra, form colored salts and double salts, have a low electrode potential, are mainly amphoteric, yield weak bases and weak acids, and are oxidizing or reducing agents (From Grant & Hackh's Chemical Dictionary, 5th ed)	Heavy Metal,Heavy Metals,Metal, Heavy