Trace elements molybdenum

In summary, we may add that bacterial utilization of quinoline and its derivatives as a rule depends on the availability of traces of molybdate in the culture medium [363], In contrast, growth of the bacterial strains on the first intermediate of each catabolic pathway, namely, the lH-2-oxo or 1 II-4-oxo derivatives of the quinoline compound was not affected by the availability of molybdate. This observation indicated a possible role of the trace element molybdenum in the initial hydroxylation at C2. In enzymes, Mo occurs as part of the redox-active co-factor, and all the Mo-enzymes involved in N-heteroatomic compound metabolism, contain a pterin Mo co-factor. The catalyzed reaction involves the transfer of an oxygen atom to or from a substrate molecule in a two-electron redox reaction. The oxygen is supplied by the aqueous solvent. Certainly, the Mo-enzymes play an important role in the initial steps of N-containing heterocycles degradation. 

Anke M, Groppel B. 1987. Toxic actions of essential trace elements (molybdenum, copper, zinc, iron and manganese). Trace Element Anal Chem Med Biol 4 201-236. 

Cornells, R., Versieck, J., Desmet, A., Mees, L. and Vanballenberghe, L. (1981). Neutron activation analysis of the trace element molybdenum in urine of healthy persons. Bull. Soc. Chim. Beiges 90, 289. 

If plants do not obtain sufficient quantities of the essential trace elements, growth is inhibited and crop yields are decreased. Spectroscopic methods are used to study trace element composition of plants and to diagnose deficiency problems in them. Recommendations can then be proposed for remedial treatment by application of deficient elements through soil applications or through sprays applied to the leaves. There are many examples of deficiencies that have been corrected through application of specific trace elements. Molybdenum frequently is added to fertilizers, as are boron and copper. In some areas iron and zinc are deficient and are added to fertilizers. 

Cobalt, copper, molybdenum, iodine, iron, manganese, nickel, selenium, and zinc are sometimes provided to mminants. Mineral deficiency or toxicity in sheep, especially copper and selenium, is a common example of dietary mineral imbalance (21). Other elements may be required for optimal mminant performance (22). ExceUent reviews of trace elements are available (5,22). 

Molybdenum, recognized as an essential trace element for plants, animals, and most bacteria, is present in a variety of metaHo enzymes (44—46). Indeed, the absence of Mo, and in particular its co-factor, in humans leads to severe debility or early death (47,48). Molybdenum in the diet has been impHcated as having a role in lowering the incidence of dental caries and in the prevention of certain cancers (49,50). To aid the growth of plants. Mo has been used as a fertilizer and as a coating for legume seeds (51,52) (see FERTILIZERS Mineral NUTRIENTS). 

It appears that chromium(III) is an essential trace element in mammalian metabolism and, together with insulin, is responsible for the clearance of glucose from the blood-stream. Tungsten too has been found to have a role in some enzymes converting CO2 into formic acid but, from the point of view of biological activity, the focus of interest in this group is unquestionably on molybdenum. 

The Fermentation Process The process by which this antifungal substance is produced is an aerobic fermentation of an aquaous nutrient medium inoculated with a pimaricin-producing strain of Streptomycesgihrosporeus. The nutrient medium contains an assimilable source of carbon such as starch, molasses, or glycerol, an assimilable source of nitrogen such as corn steep liquor and Inorganic cations such as potassium, sodium or calcium, and anions such as sulfate, phosphate or chloride. Trace elements such as boron, molybdenum or copper are supplied as needed in the form of impurities by the other constituents of the medium. 

The sotrace elements, such as boron, cobalt, iron,copper, zinc, manganese, chromium, molybdenum and still others may also be used to advantage. Generally, these trace elements occur in sufficient quantities in the carbonaceous and nitrogenous constituents of the medium, particularly if derived from natural sources, or in the tap water, and the addition of further quantities of these trace elements may consequently be unnecessary. 

Tungsten ores often contain traces of molybdenum that need to be determined before the ore is processed. When the tungsten content is known, as it usually is, that element can serve as a built-in standard for the determination of molybdenum. In the work to be described, the intensity ratio was measured for molybdenum Ka and tungsten Lyl. The general approach thus resembles that of Eddy and Laby to the analysis of brass (7.10), but conditions are less favorable in the present instance. The background corrections necessary were somewhat involved, and they will be discussed in Chapter 8. See Figure 8-1 c. 

Soil pH is easily tested for and determines the availability of nutrients and the success of white clover. Very acid soils (below pH 5.0) will cause a deficiency of the trace elements iron, boron, copper and molybdenum and conversely will cause injury to plant growth by increasing the availability of aluminium and manganese to toxic levels. Over-liming, on the other hand, which can raise the pH above 6.5, will reduce the availability of certain essential elements such as phosphorus, manganese and boron. 

Shriadah et al. [516] determined molybdenum VI in seawater by densitometry after enrichment as the Tiron complex on a thin layer of anion exchange resin. There were no interferences from trace elements or major constituents of seawater, except for chromium and vanadium. These were reduced by the addition of ascorbic acid. The concentration of dissolved molybdenum (VI) determined in Japanese seawater was 11.5 pg/1, with a relative standard deviation of 1.1%. 

The CL signal arises from the reaction of luminol with I2 produced by the latter reaction. Other reactions are also available including KIO3-KI [68], H202-KI [69], and H202-Na2S203 reactions [70] catalyzed by Mo(VI), among others. Similar reactions could also be used for the determination of trace vanadium(V) ions [71, 72], The developed methods were applied to the determination of trace elements in natural waters and other matrices with detection limits below the ng/mL levels for traces of molybdenum and vanadium. 

Chromium has proved effective in counteracting the deleterious effects of cadmium in rats and of vanadium in chickens. High mortality rates and testicular atrophy occurred in rats subjected to an intraperitoneal injection of cadmium salts however, pretreatment with chromium ameliorated these effects (Stacey et al. 1983). The Cr-Cd relationship is not simple. In some cases, cadmium is known to suppress adverse effects induced in Chinese hamster (Cricetus spp.) ovary cells by Cr (Shimada et al. 1998). In southwestern Sweden, there was an 80% decline in chromium burdens in liver of the moose (Alces alces) between 1982 and 1992 from 0.21 to 0.07 mg Cr/kg FW (Frank et al. 1994). During this same period in this locale, moose experienced an unknown disease caused by a secondary copper deficiency due to elevated molybdenum levels as well as chromium deficiency and trace element imbalance (Frank et al. 1994). In chickens (Gallus sp.), 10 mg/kg of dietary chromium counteracted adverse effects on albumin metabolism and egg shell quality induced by 10 mg/kg of vanadium salts (Jensen and Maurice 1980). Additional research on the beneficial aspects of chromium in living resources appears warranted, especially where the organism is subjected to complex mixtures containing chromium and other potentially toxic heavy metals. 

Karring, M., R. Pohjanvirta, T. Rahko, and H. Korpela. 1981. The influence of dietary molybdenum and copper supplementation on the contents of serum uric acid and some trace elements in cocks. Acta Vet. Scand. 22 289-295. 

Underwood, E.J. 1971. Trace Elements in Human and Animal Nutrition. Chapter 4. Molybdenum. Academic... 

Clinical syndromes are associated with deficiencies of the following trace elements zinc, copper, manganese, selenium, chromium, iodine, fluoride, molybdenum, and iron. 

Zinc, copper, chromium, manganese, and possibly selenium and molybdenum are the only trace elements that require supplementation during PN. 

Requirements for trace elements during organ failure are not clearly defined. Manganese and copper should be restricted or withheld in patients with cholestatic liver disease. Chromium, molybdenum, and selenium should be restricted or withheld in patients with renal failure. 

Nixon277 compared atomic absorption spectroscopy, flame photometry, mass spectroscopy, and neutron activation analysis as methods for the determination of some 21 trace elements (<100 ppm) in hard dental tissue and dental plaque silver, aluminum, arsenic, gold, barium, chromium, copper, fluoride, iron, lithium, manganese, molybdenum, nickel, lead, rubidium, antimony, selenium, tin, strontium, vanadium, and zinc. Brunelle 278) also described procedures for the determination of about 20 elements in soil using a combination of atomic absorption spectroscopy and neutron activation analysis. 

In addition to carbon and hydrogen, the key elements in the molecules of life include nitrogen, oxygen, phosphorus, and sulfur. Also, a family of trace elements is required sodium, potassium, magnesium, manganese, calcium, chlorine, fluorine, iodine, iron, copper, nickel, cobalt, zinc, molybdenum, silicon and vanadium. 

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