Nutrient requirements Cobalt

In addition to provision of carbon, other nutrients required by microorganisms embrace nitrogen, phosphorus, and oxygen, all elements of which are part of the structural and functional molecules of the cell. Smaller quantities of micronutricnLs are needed. The requirement for cobalt in the synthesis of cobalamin is one of these obvious requirements. 

Nutrients required by crops can be divided up into major elements and micro (trace) elements (Table 4.2). Micro (trace) elements include boron, copper, iron, manganese, molybdenum, zinc and cobalt, some of which are dealt with later in this chapter. 

It is clear from the data in Table 3 that depletion can be a significant factor which affects the ability of mineral soils to meet the nutrient requirements of plants with respect to molybdenum, boron and copper and that when the total soil levels of these elements are low, crop requirements can only be met for limited periods. For example, an acre of soil containing only 1 ppm boron cannot possibly produce more than 100 tons of crop dry matter with a content of 10 ppm boron. In practice, the boron content is likely to be around 40 ppm in the dry matter and this would limit the total possible yield on such a soil to 25 tons of crop dry matter. Deficiency conditions involving these elements are therefore inevitable within decades on cultivated land, if no steps are taken to replace cropping losses. Deficiency problems involving manganese and cobalt, on the other hand, are more likely to be due to a reduction of availability in the soil than to depletion of the total soil reserves. 

The amount of each element required in daily dietary intake varies with the individual bioavailabihty of the mineral nutrient. BioavailabiUty depends both on body need as deterrnined by absorption and excretion patterns of the element and by general solubiUty, and on the absence of substances that may cause formation of iasoluble products, eg, calcium phosphate, Ca2(P0 2- some cases, additional requirements exist either for transport of substances or for uptake or binding. For example, calcium-binding proteias are iavolved ia calcium transport an intrinsic factor is needed for vitamin cobalt,... 

Agriculture therefore depends on there being a sufficient supply of inorganic nutrients to plants. Cereals, vegetables, fruit-bearing trees or plants, and animal fodder require bioavailable nutrients, that is, nutrients in forms that they can use. Since intensive agriculture depletes many natural nutrients, synthetic nutrients (fertilizers) must be supplied.1-7 In particular, we need to fix the inert N2 of the atmosphere as soluble, reactive compounds such as nitrates, ammonia, and ammonium salts. Other major fertilizer components are sulfate, potassium, and phosphate ions. It may also be necessary to provide trace nutrients, such as cobalt compounds, or to remove excess soil acidity by treatment with lime (CaO). World fertilizer demand in the year 2001 is expected to be about 1.5 x 10s metric tons N, 7.6 x 107 metric tons P2O5, and 6.7 x 107 metric tons K2O these projections represent an... 

A typical medium for natural product accretion must supply the necessary nutrients for cell growth and product biosynthesis. The nutrients include sources of carbon, nitrogen, phosphorus, sulfur, potassium, and traces of elements such as iron and cobalt. In many cases, the use of undefined or complex nitrogen sources such as soya flour will provide sufficient levels of phosphate, sulfate, and other ions. Indeed, some simple media may consist of nothing more than a carbon source and a nitrogen source supplemented with a mixture of trace elements. In some cases, significant quantities of calcium carbonate or phosphate ions may be added to buffer the pH rather than to satisfy a specific elemental requirement (4). 

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. 

As Table 3.1 indicates, at least seven metals have been identified as human carcinogens, primarily of the lung. This may lead to the conclusion that these metals are extremely dangerous, and that any contact may result in cancer. On the contrary, based on available epidemiological evidence, it appears that the majority of metal-associated cancers are the result of chronic overexposure over a period of years or decades. With the exception of arsenic and lead, metal-induced cancers are largely preventable through the use of proper environmental controls or respiratory protective equipment. Surprisingly, two of the seven metals listed in Table 3.1, chromium and cobalt, are required in minute quantities as essential nutrients. Three others (arsenic, cadmium, and lead) may also be essential dietary nutrients. As Paracelsus indicated, it is not the substance that makes the poison, but the dose. 

Plant cells and animal cells share most of the same metabolic systems, and with a few exceptions, plants require the same array of nutrients as animals. Most of this overlap occurs in the macrominerals and some microminerals. But plants also have their own special needs for elements that our livestock cannot use, like boron, which is involved in fiber metabolism, and molybdenum, which is used in nitrogen metabolism and nitrogen fixation. But what about the three minerals that plants don t need—iodine, cobalt, and selenium ... 

Recommended dietary allowances for a male adult (daily intake, in foods and food supplements) of some nutrients, usually the amounts estimated as needed to prevent overt manifestation of deficiency disease in most persons. For the substances listed in smaller amounts the optimum intake, leading to the best of health, may be somewhat greater. Not shown, but probably or possibly required, are the essential fatty acids, />aminobenzoic acid, choline, vitamin D, vitamin K, chromium, manganese, cobalt, nickel, zinc, selenium, molybdenum, vanadium, tin, and silicon. 

These are nutrients that are present in the body, and required by the body in minute quantities, ranging from millionths of a gram (microgram) to thousandths of a gram (milligram). Examples are vitamin B-12, pantothenic acid, chromium, cobalt, copper, fluorine, iodine, iron, manganese, molybdenum, selenium, silicon, and zinc. Their minuteness in no way diminishes their importance to human nutrition-many are known to be absolutely essential. 

FUNCTIONS. In the human body, vitamin B-12 is converted to a coenzyme form, if it is not already in such form. There are two active coenzyme forms Coenzyme B-12 (ade-nosylcobalamin), and methyl B-12 (methylcobalamin). Coenzyme B-12 has an adenosine ribonucleoside attached to the cobalt atom in the vitamin B-12 molecule in place of the cyanide group, whereas methyl B-12 contains a methyl group in place of the cyanide group. The conversion of vitamin B-12 to coenzyme forms requires many nutrients, including riboflavin, niacin, and magnesium. 

Usually, the synthesis of zeolite materials requires an excess amount of reactant reagents. After the resultant products are filtered from the reaction mixture, the filtrate (mother-liquor) containing abundant nutrients is discarded as a waste solution. With the concept of green chemistry, Yu and coworkers attempted a mother-liquor-reused route to synthesize cobalt aluminophosphate zeolites CoAPO-CJ51 (GIS) and CoAPO-CJ52 (LAU) by introducing Co + cations into the filtrated mother liquors of two layered aluminophosphates Mu-4 and AlPO-IM, respectively [47]. The mother-liquor-reused route provides a low-cost way for the synthesis of zeolite materials. 

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