Atrazine, metolachlor, carbaryl, and chlorothalonil are detected in streams throughout the U.S. at concentrations that may have adverse effects on benthic microbes. Sediment samples were exposed to these pesticides to quantify responses of ammonium, nitrate, and phosphate uptake by the benthic microbial community. Control uptake rates of sediments had net remineralization of nitrate (-1.58 NO3 ...

Plants take up inorganic nitrogen (N) primarily as nitrate but also to a lesser extent as ammonium. Nitrate is reduced to nitrite in the cytoplasm by the highly regulated enzyme nitrate reductase. Nitrite is transported into the chloroplast and further reduced by nitrite reductase to ammonium. Ammonium is assimilated into the amino acid pool by the coordinate action of Gln synthetase (GS) and G...

The development of titrimetric sensor applications to monitor biological wastewater treatment processes is shortly described, and the measurement principle (based on a pH controller) is illustrated. 3 applications that were developed during the past years are used to illustrate the capabilities of titrimetric sensors. The ammonium and the nitrate concentration can be measured to monitor the nit...

Excised 7-day-old oat (Avena sativa L. cv. Jaycee) leaves were incubated in media containing 7.1 millimolar KNO(3) and 0.15 millimolar tabtoxin or 1 millimolar methionine sulfoximine (MSO) to investigate the sources of the observed ammonium accumulated. Tabtoxin and MSO are known inhibitors of glutamine synthetase, the first enzyme in the primary pathway of ammonium assimilation. During a 4- to...

The specific activities of nitrate reductase, nitrite reductase, glutamine synthetase, glutamate synthase, and glutamate dehydrogenase were determined in intact protoplasts and intact chloroplasts from Chlamydomonas reinhardtii. After correction for contamination, the data were used to calculate the portion of each enzyme in the algal chloroplast. The chloroplast of C. reinhardtii contained all...

An adjuvant composition containing a) one or more alkyl glucamides of the formula (I), wherein R1 represents a linear or branched alkyl group having 5 to 9 carbon atoms, R2 represents an alkyl group having 1 to 3 carbon atoms; b) at least one water-soluble ammonium salt, preferably selected from the group consisting of ammonium sulfate, ammonium nitrate, ammonium nitrate urea, ammonium phosphat...

Growing vegetables economically in the use of constructed wetland for wastewater treatment can play a role in overcoming water and food scarcity. Allium porrum L., Solanum melongena L., Ipomoea aquatica Forsk., and Capsicum annuum L. plants were selected to grow in hybrid constructed wetland (CW) under natural conditions. The impact of the ratio of nitrate to ammonium nitrogen on ammonium and n...

Using ammonium nitrate (AN) as a propellant oxidizer is limited due to its hygroscopicity. This review consolidated the available information of various issues pertaining to the coating methods of the surface modification of ammonium nitrate for reducing its hygroscopicity. Moreover this review summarizes the recent advances and issues involved in ammonium nitrate surface modification by physic...