Azotobacter synthesizes an extensive internal membranous nework when grown with air (N(2)), i.e., under conditions when these bacteria fix nitrogen. Very slight quantities of internal membrane, concentrated mainly about the cell periphery, are formed when Azotobacter grows with fixed nitrogen, i.e., ammonia and amino acids. Compared to cells growing with ammonia, cells utilizing atmospheric nit...

dissolved organic nitrogen (don) can react with disinfectants to produce numerous disinfectionbyproducts (dbps), particularly nitrogen-containing dbps (n-dbps), and produce serious adverse effectson public health. widely used biological processes in drinking water treatment can increase don in effluents,and enhance these ill effects. this study investigated don in a full-scale two-stage ozonati...

Catasetum fimbriatum is an epiphytic orchid from South America that has been used for 15 years as a model plant for metabolic and developmental studies in our laboratory. In this work, C. fimbriatum plants were aseptically grown with 6 mol m(-3) of either glutamine or inorganic nitrogen forms (NO(3)(-):NH(4)(+) ratios). The highest biomass accumulation was found in plants supplied with glutamin...

A missing link in the nitrogen cycle has recently been found: bacteria capable of oxidizing ammonium to nitrogen gas (N2). This new source of N2 has now been detected in both the water column and the sediments in marine environments. This discovery is important because it necessitates re-evaluation of (1) major fluxes in the global nitrogen budget and (2) regulation of the processes leading to ...

UNLABELLED Nitrogen regulation in Escherichia coli is a model system for gene regulation in bacteria. Growth on glutamine as a sole nitrogen source is assumed to be nitrogen limiting, inferred from slow growth and strong NtrB/NtrC-dependent gene activation. However, we show that under these conditions, the intracellular glutamine concentration is not limiting but 5.6-fold higher than in ammoniu...

Glycine has been regarded as a poor source of nitrogen for total parenteral nutrition. Two prospective randomised cross over controlled clinical trials were undertaken to compare the efficacy of high and low glycine containing amino acid solutions in parenterally fed malnourished hypoalbuminaemic patients with gastrointestinal disease. In the first study (n = 9), amino acid solutions in which g...

Experiments in a lab-scale SBR were conducted to demonstrate the feasibility of using an internal carbon source (non-digested pig manure) for biological nitrogen and phosphorus removal in digested piggery wastewater. The internal C-source used for denitrification had similar effects to acetate. 99.8% of nitrogen and 97.8% of phosphate were removed in the SBR, from an initial content in the feed...

nitrogen concentration, temperature and light intensity. Nitrogen is one of the essential nutrients critical for the cultivation of algae due to its role in growth and regulation of metabolism [1]. It is well documented that there are three different sources of nitrogen such as nitrate, ammonia and urea, which are absorbed by microalgae [2,3]. Urea is known to contain approximately 46.7% nitrog...

The nitrogen cycle is fundamental to Earth’s biogeochemistry. Yet major uncertainties of quantification remain, particularly regarding the global oceanic nitrogen fixation rate. Hydrogen is produced during nitrogen fixation and will become supersaturated in surface waters if there is net release from diazotrophs. Ocean surveys of hydrogen supersaturation thus have the potential to illustrate th...

The uptake of methylamine as the sole nitrogen, but not carbon, source by Pseudomonas sp. strain MA was investigated. Under these growth conditions, a high-affinity, low-capacity uptake system was present having a Km of 16 microM and Vmax of 2 nmol.min-.mg (dry weight) of cells that was competitively inhibited by ammonium chloride. The transport system was induced by growth on succinate with me...