Traditional models of chemostat systems looking at interactions between predator, prey and nutrients have used only a single currency, such as energy or nitrogen. In reality, growth of autotrophs and heterotrophs may be limited by various elements, e.g. carbon, nitrogen, phosphorous or iron. In this study we develop a dynamic energy budget model chemostat which has both carbon and nitrogen as c...

In China, excessive use of nitrogen fertilizers in glasshouses leads to nitrate accumulations in soil and plants, which then limits productivity. Melatonin, an evolutionarily highly conserved molecule, has a wide range of functions in plants. We analyzed the effects of melatonin pretreatment on the growth, mineral nutrition, and nitrogen metabolism in cucumber (Cucumis sativus L. "Jin You No. 1...

The capacity for nitrate reduction, as measured by nitrate reductase activity (NRA), was generally low for a range of plant communities in Australia (coastal heathland, rainforest, savanna woodland, monsoon forest, mangrove, open Eucalyptus forest, coral cay open forest) and only a loose relationship existed between NRA and leaf nitrogen concentration. This suggests that nitrate ions are not th...

Introduction The mycelium of woodland fungi can act both as a reservoir and as a distribution system for nutrients, owing to its physiological and developmental adaptations to life at the interface between organic and mineral soil horizons. The mobility of accumulated nitrogen and phosphorus within the mycelial networks of cord-forming wood decay fungi and ectomycorrhiza enables fungi to play k...

For preliminary screening for and characterization of free-living nitrogen-fixing bacteria from rhizoplane microflora, we used Winogradsky's mineral mixture-based nitrogen-free medium solidified with 0.3% gellan gum. The soft gel medium enabled some reference and wild free-living nitrogen-fixing bacteria to grow in characteristic colonies, including their reaction to oxygen and their motility c...

Black Sea receives 1,125,839 tons of organic matter, 575,000 tons mineral nitrogen, 55,000 tons mineral phosphorus, 30,000 tons organic phosphorus, 90,000 tons iron, 206,000 tons petroleum and petroleum products, 48,000 tons surfactant, 12,000 tons zinc, 67,000 tons manganese, 4,500 tons lead, 2,800 tons copper, 900 tons cadmium and 80 tons of mercury in a year from land based sources. All thes...

The content of flavonoids increases in response to nitrogen and phosphorus depletion in plants. Manipulation of these macronutrients may therefore be used to control the levels of desirable compounds and improve plant quality. Key enzymes in the shikimate pathway, which feeds precursors into the flavonoid pathway, are regulated post-translationally by feedback from aromatic amino acids, and pos...

Introduction Mineral dust aerosol plays a critical role in atmospheric chemistry by providing reactive surfaces for trace atmospheric gases. 1-3 Mineral dust particles undergo heterogeneous reactions with nitrogen oxides in the atmosphere to yield adsorbed nitrate, nitrate coatings or deliquesced nitrate layers. 1,4,5 Reactions that can alter NOx (NOx = NO + NO2) concentrations are of great imp...

The mineral composition of the microbial mats at La Banya spit was studied. The spit is formed by a narrow sand bar and a peninsula and is located south of the main body of the Ebro Delta (Tarragona, Spain). Although quartz was the predominant mineral component in all sampling sites, clay, feldspars, calcite, aragonite, halite, dolomite and gypsum were also found. An increase in both the fine m...