New Sources of the Nutrient

Numerous analyses performed during the nineteenth century on guanos from different locations showed a fairly wide range of moisture content (11-25%) and even more variable nitrogen content ranging from about 15% (exceptionally up to about 20%) for the best guanos from arid locations to less than 1% for heavily leached materials from wetter tropical and subtropical sites (appendix E). The element was bound in urates and phosphates, as well as in rather volatile ammonium carbonate, (NH4)2C03. 

Guano was used to fertilize crops along the western coast of South America long before the Inca empire, and the Incas extended the practice to highland crops. Spanish conquerors were impressed by the fertilizer s effects but made no effort to introduce it to Europe. The first small lump of guano was brought to the continent from 

Antoine-Fran ois de Fourcroy (1755-1809), an experienced French chemist and a co-author of the Lavoisier-inspired Methode de Nomenclature Chimique, was one of the researchers who analyzed Humboldt s sample and confirmed its high nitrogen 

Ichaboe Island off the coast of Southwest Africa was the source of the first non-Peruvian guano by 1843, just three years after their discovery, these deposits (amounting to some 300,000 t) were stripped bare. Later non-Peruvian exports included shipments from Caribbean islands (Sombrero in the Leeward Islands, Na-vassa west of Haiti, tiny islands off Yucatan and Venezuela), as well as from Bolivia, Brazil, Australia, and the island of St. Helena in the South Atlantic. None of these deposits had as much nitrogen as the Chincha guanos. So-called rock or crust guanos 

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The increased export of products leads to a new constellation of the nutrient and humus balance, to a higher dependency on external sources of nutrients and, if there is an intensification of the cropping systems, to an increased dependency on the plant protection products. Accordingly, the technical requirements increase. 

Of the various new sources of nutrients, especially proteins, microbial biomass shows great potential. This applies particularly to yeasts which have a long tradition of successful use as foods, as producers of foods and beverages, and as food ingredients (1,2,3,4,5). The interest in and the supply of yeast and microbial biomass will increase rapidly with the growing activities in biomass conversion (alcohol production, etc.). Microbial biomass can become a significant source of food protein... 

Other New Markets. Moving away from the automobile fuel market, ICI and Phillips Petroleum have developed single cell protein (SCP) products made by the growth of a microorganism that uses methanol as the sole source of carbon nutrient. These SCP s aim at the animal feed market as high protein additives in competition with skimmed milk powder and fish meal. If this process proves successful it offers a potential future additional consumption of methanol, although not in the same league as the possible fuel market. 

Cobalt is one of twenty-seven known elements essential to humans (28) (see Mineral NUTRIENTS). It is an integral part of the cyanocobalamin [68-19-9] molecule, ie, vitamin B 2> only documented biochemically active cobalt component in humans (29,30) (see Vitamins, VITAMIN Vitamin B 2 is not synthesized by animals or higher plants, rather the primary source is bacterial flora in the digestive system of sheep and cattle (8). Except for humans, nonmminants do not appear to requite cobalt. Humans have between 2 and 5 mg of vitamin B22, and deficiency results in the development of pernicious anemia. The wasting disease in sheep and cattle is known as bush sickness in New Zealand, salt sickness in Florida, pine sickness in Scotland, and coast disease in AustraUa. These are essentially the same symptomatically, and are caused by cobalt deficiency. Symptoms include initial lack of appetite followed by scaliness of skin, lack of coordination, loss of flesh, pale mucous membranes, and retarded growth. The total laboratory synthesis of vitamin B 2 was completed in 65—70 steps over a period of eleven years (31). The complex stmcture was reported by Dorothy Crowfoot-Hodgkin in 1961 (32) for which she was awarded a Nobel prize in 1964. 

Fig. 10-13. The links between the cycling of C, N, and O2 are indicated. Total primary production is composed of two parts. The production driven by new nutrient input to the euphotic zone is called new production (Dugdale and Goering, 1967). New production is mainly in the form of the upward flux of nitrate from below but river and atmospheric input and nitrogen fixation (Karl et al, 1997) are other possible sources. Other forms of nitrogen such as nitrite, ammonia, and urea may also be important under certain situations. The "new" nitrate is used to produce plankton protoplasm and oxygen according to the RKR equation. Some of the plant material produced is respired in the euphotic zone due to the combined efforts...

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