In developing leaves of Pisum sativum the levels of ammonium did not change during the light-dark photoperiod even though asparaginase (EC 3.5.1.1) did; asparaginase activity in detached leaves doubled during the first 2.5 hours in the light. When these leaves were supplied with 1 millimolar methionine sulfoximine (MSX, an inhibitor of glutamine synthetase, GS, activity) at the beginning of the...

the effect of salinity on organic removal and ammonium oxidation in a down-flow hanging sponge reactor was investigated by conducting a long-term continuous experiment over a period of 800 days. the dhs reactor, constructed by connecting three identical units, was fed with artificial wastewater containing 500 mg-n/l of ammonium nitrogen and 1400 mg- cod/l of phenol. salinity of the influent wa...

ammonium ions wastewater pollution has become one of the most serious environmental problems today. the treatment of ammonium ions is a special concern due to their recalcitrance and persistence in the environment. in recent years, various methods for ammonium ion removal from wastewater have been extensively studied. this paper reviews the current methods that have been used to treat ammonium ...

Ammonium ions are ubiquitous in chemistry and molecular biology. Considerable efforts have been undertaken to develop synthetic receptors for their selective molecular recognition. The type of host compounds for organic ammonium ion binding span a wide range from crown ethers to calixarenes to metal complexes. Typical intermolecular interactions are hydrogen bonds, electrostatic and cation-π in...

Soybean cell suspension cultures grew on defined media with ammonium as the sole nitrogen source if Krebs cycle acids were added. Satisfactory growth was obtained with ammonium salts of citrate, malate, fumarate, or succinate, when compared with the regular medium containing nitrate and ammonium. Little or no growth occurred when ammonium salts of shikimate, tartrate, acetate, carbonate, or sul...

The present-day wastewater treatment practices can be significantly improved through the introduction of new microbial treatment technologies. Recently, several new processes for nitrogen removal have been developed. These new nitrogen removal technologies provide practicable options for treating nitrogen-laden wastewaters. The new processes are based on partial nitrification of ammonium to nit...

Ammonium production in the presence of specific inhibitors of sulfate reduction and methanogenesis was investigated in six marine sediments which differed in bulk properties and organic matter input. In all cases, little effect of the inhibitors on ammonium production was observed, although sulfate reduction was suppressed by molybdate. This gives evidence that the processes of fermentation and...