Trace organic nutrients

The continued production of organic matter in the sea requires the availability of the many building blocks of life, including essential major elements such as carbon (C), nitrogen (N), and phosphorus (P) essential minor elements such as iron, zinc, and cobalt and, for many marine organisms, essential trace organic nutrients that they cannot manufacture themselves (e.g., amino acids and vitamins). These required nutrients have diverse structural and metabolic function and, by definition, marine organisms cannot survive in their absence. 

Of more apparent significance in the aquatic environment are redox processes induced or enhanced on absorbance of light by chromophores at metal oxide surfaces in which the metal of the oxide lattice constitutes the cationic partner. Light induced electron transfer within such a chromophore often results in disruption of the oxide lattice. The photoredox-induced dissolution of iron and manganese oxides by such a mechanism has been proposed as a possible means of supply of essential trace-metal nutrients to plants and aquatic organisms (29-31). ... 

Seawater studies require certified reference materials for biologically important dissolved components such as carbon (both inorganic and organic), nutrients, and trace metals, as well as for salinity, which is hydro-graphically important. A number of the committee s key recommendations therefore explicitly address these parameters. There is also a striking need for reference materials based on particulate matrices, where many of the analytical techniques used are matrix dependent and differ markedly... 

Iron is an essential trace metal nutrient required by practically all living organisms for a wide variety of fundamental cell functions ranging from oxygen metabolism and electron transfer processes to DNA and RNA synthesis . ... 

G. V. Iyengar, W. R. Wolf, J. T. Tanner, E. R. Morris, Content of minor and trace elements, and organic nutrients in representative mixed total diet composites from USA, Sci. Total Environ., 256 ( 2000), 215-226. 

Appropriate nutrition for all organisms is a matter of both quantity and balance. For good nutritional health, all of the essential inorganic and organic nutrients must be available, but they must be obtainable in an appropriate balance. A severe shortage of even a micronutrient required in trace quantities can result in severe metabolic dysfunctions, and even death of organisms. 

The association of pollutants such as trace metals, nutrients, and toxic organic molecules to colloids is intimately connected to the health of natural waters. Colloids, with their large specific surface area, play a dominant role in the transportation and eventual deposition of these pollutants. Of particular interest is the size speciation data. It is important to know not only the total amount of pollutant present but also where it is distributed. It has been inherently difficult to study pollutant-colloid interactions because of the lack of methods for particle size determination and fractionation as well as the low concentrations of pollutants present in many systems. This entry outlines a new approach using field-flow fractionation (FFF). 

This Is a compilation of papers presented at the WEF 1992 conference covering adsorption/metal removal, biological nutrient removal, biological treatment, physical and chemical treatment, biological treatment of trace organics, and fate and treatment of trace organics. 

Concentrations of many trace element nutrients (zinc, cadmium, iron, copper, nickel, and selenium) increase with depth in the ocean, similar to increases observed for major nutrients (nitrate, phosphate, and silicic acid) (Figures 2—4). In the central North Pacific, filterable concentrations of zinc and cadmium increase by 80-fold and 400-fold, respectively, between the surface and 1000-m depth. The similarity between vertical distributions of these trace elements and major nutrients indicates that both sets of nutrients are subject to similar biological uptake and regeneration processes. In these processes, both major and trace element nutrients are efficiently removed from surface waters through uptake by phytoplankton. Much of these assimilated nutrients are recycled within the euphoric zone by the coupled processes of zooplankton grazing and excretion, viral lysis of cells, and bacterial degradation of organic... 

The intensity of microbial growth on plastic material depends on the type of synthetic polymer, but also on the type of additives, especially plasticizers used to improve the processing characteristics of the polymer. There are plasticizers such as fatty acid esters and long-chain dicarboxylic acid esters which are most susceptible to fungal growth while phthalate and phosphate esters with alkylol substituents are generally resistant. However, as plastic materials in operation are always subject to contamination with traces of nutrients for micro-organisms. 

The distribution of trace organic compounds such as chlorobiphenyls (CBs) and polycyclic aromatic hydrocarbons (PAHs) in seawater and marine particulate matter is determined by the complex influence of physical, biological and chemical processes. The interpretation of horizontal and vertical distribution patterns of these substances requires information on the corresponding characteristics of the water bodies, e.g., temperature, salinity, depth and the concentrations of nutrients and dissolved oxygen. 

In the last decade, the reclamation of effluents has developed rapidly as an altemative to seawater desalination for industrial uses, irrigation, and indirect potable water reuse. For water reclamation, contaminants that require treatment over and above what is provided by conventional biological treatment include suspended solids, microbes, nutrients (nitrogen and phosphorus, trace organic compounds (e.g., pesticides, endocrine disraptor compounds), and in certain cases dissolved salts. 

Under these circumstances, it is necessary for the organisms inhabiting these waters, espedally elements of the microbiota, to be physiologically adiq>ted to absorb and effidenfly store every available trace of nutrient entering ibe water. That this is happening is indicated by the decrease in the conductivity fi-om values of 13.18,9.66, and 4.72 pS/cm in the three headwater springs to 3.32 pS/cm in the river downstream fi om the confluence of the three streams they feed. 

The elemental and vitamin compositions of some representative yeasts are Hsted in Table 1. The principal carbon and energy sources for yeasts are carbohydrates (usually sugars), alcohols, and organic acids, as weU as a few other specific hydrocarbons. Nitrogen is usually suppHed as ammonia, urea, amino acids or oligopeptides. The main essential mineral elements are phosphoms (suppHed as phosphoric acid), and potassium, with smaller amounts of magnesium and trace amounts of copper, zinc, and iron. These requirements are characteristic of all yeasts. The vitamin requirements, however, differ among species. Eor laboratory and many industrial cultures, a commercial yeast extract contains all the required nutrients (see also Mineral nutrients). 

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