Nutrients, acid effects

The nutrient sparing effect of antibiotics may result from reduction or elimination of bacteria competing for consumed and available nutrients. It is also recognized that certain bacteria synthesize vitamins (qv), amino acids (qv), or proteins that may be utilized by the host animal. Support of this mode of action is found in the observed nutritional interactions with subtherapeutic use of antibiotics in animal feeds. Protein concentration and digestibiHty, and amino acid composition of consumed proteins may all influence the magnitude of response to feeding antibiotics. Positive effects appear to be largest... 

In Norway comprehensive investigations of acid precipitation effects have taken place (Overrein, Seip and Tollan, 1980). Fish death caused by such influences in some districts in southern Norway has been proved. The soil material in this region is often shallow, coarse grained and derived from bedrock rich in silisium. The buffer capacity is therefore low and the acid effect of the precipitation will quickly be noticed. On the other hand, there has so far not been proved any decrease in the growth of the forest. In this connection we must remember that the acid precipitation also contributes with the nutrient element nitrogen. 

Complete solution changes for multiple phenolic acid treatments were used because phenolic acids supplied to seedlings in the nutrient culture system disappeared from the nutrient solution within 24-48 h (Blum and Dalton 1985 Blum and Gerig 2005). This was due to microbial metabolism, physical breakdown, and/or root uptake. Since we did not want to confound nutrient and phenolic acid effects, complete solution changes were made. An additional benefit of this approach was to reset phenolic acid concentrations to the initial treatment levels for each solution change. This was important since recovery of seedling processes occurred rapidly after phenolic acid depletion (Blum and Dalton 1985 Blum and Rebbeck 1989 Blum and Gerig 2005). 

Finally, similar to what had been observed in nutrient culture, effects of phenolic acids on cucumber seedlings were greater under acidic conditions than under neutral conditions, e.g., the dose required for a given percent inhibition of absolute and... 

In summary, observed effects of individual phenolic acids or phenolic acid mixtures were similar to what had been observed in nutrient culture but the response times and the magnitude of effects (see Section 2.4.8 for direct comparison) were slower and lower, respectively. Relative potencies of phenolic acids were lower when compared to nutrient culture. Increasing the number of phenolic acids in a mixture of phenolic acids reduced the concentrations of the individual phenolic acids required for a given percent inhibition. The presence of other readily available organic compounds (inhibitory or non-inhibitory) also reduced the concentration of phenolic acids required for a given percent inhibition. The addition of nitrate or nutrient solution reduced the inhibitory activity of phenolic acids. The inhibition of methionine, an amino acid, on the other hand was enhanced by the addition of nitrate. Finally phenolic acid effects were greater under acidic than under neutral conditions. 

Neutralization of Episodic and Longer-term Acidity OTHER EFFECTS OF ACIDIFICATION. 5.1 Release of Aluminum and Other Metals. 5.2 Nutrient Availability EFFECTS OF CLIMATE ON ACIDIFICATION. 6.1 NO3 SO4 CO2... 

BOWEN G.D. 1969. Nutrient status effects on loss of amides and amino acids from pine roots. Plant and Soil, 30, 139-142. 

Evidence for consistent, positive metaboHc effects of feeding antibiotics is fragmented and inconclusive. Direct measurement of increased uptake of nutrients, ie, in vivo amino acids, glucose, or volatile fatty acids in mminants, have not been reported. 

Soil Nutrient. Molybdenum has been widely used to increase crop productivity in many soils woddwide (see Fertilizers). It is the heaviest element needed for plant productivity and stimulates both nitrogen fixation and nitrate reduction (51,52). The effects are particularly significant in leguminous crops, where symbiotic bacteria responsible for nitrogen fixation provide the principal nitrogen input to the plant. Molybdenum deficiency is usually more prominent in acidic soils, where Mo(VI) is less soluble and more easily reduced to insoluble, and hence unavailable, forms. Above pH 7, the soluble anionic, and hence available, molybdate ion is the principal species. 

Sodium is an indispensable element for some crops (notably sugar beet), can partially substitute for potassium in several crops, contributes to neutralising soil and subsoil acidity, and has a positive effect on soil phosphoms solubiUty. Sodium is an essential nutrient for cattle, and sodium appHcation to soil increases its content in pastures. Sodium nitrate is particularly effective as a nitrogen source for sugar beet, vegetable crops, tobacco, and cotton (qv), and for any crop in acid soils. 

In addition to direct effects of chemical compounds on the fetus, metabolic disturbances in the mother, such as diabetes or hyperthermia, or deficiencies of calories or specific nutrients such as vitamin A, zinc, and folic acid may lead to teratogenesis. Compounds that inhibit placental functions may also induce malformations, e.g., by inhibiting placental circulation. For example, hydroxyurea disrupts the placental circulation and induces malformations. In addition, it also induces DNA damage. 

Biological actions Adipocyte differentiation fatty acid uptake lipogenesis glucose uptake other effects on nutrient metabolism which lower hepatic glucose production... 

---