Nitrogen and phosphorus metabolism

This Section and the next one deal with catabolic processes. Because these are known to follow fairly uniform patterns in most living cells, the expectation of variations that could be exploited selectively may not seem very high. In spite of that, some variations do exist, and a selection of them is recorded here together with indications of their use. 

Nitrogen metabolism has end-products more varied than those of fat or carbohydrate metabolisms, ranging in complexity from ammonia to the 

Ammonia Urea Uric acid (Baldwin, 1948a.) 

Some unusual amino acids occur in the cell walls of bacteria (Section 5.3). Several unusual biosyntheses of common amino acids have been recorded. Thus plants and bacteria make lysine only by decarboxylating diaminopimelic acid, but the lysine of fungi and mammals is made from 2-aminoadipic acid (Vogel, 

No amino acid of the D-series has been found in an active cell constituent of any creature higher on the evolutionary scale than the earthworm (Lumbricus terrestris), which contains the phosphagen lombricine (0-phosphodiester of guanidinoethanol and D-serine) (Ennor et aL, 1960). 

Some unusual aminoacids occur in the cell walls of bacteria (Section 

3 Nitrogen excretion of chick embryo (after Needham). 

---

G. N. Zaitseva, A. N. Belozersky and L. P. Novozhilova (1960b). The effect of the the calcium ion on nitrogen and phosphorus metabolism in Azoiohacier vinelandii (in Russian). Mikrobiologiia, 29, 343-350. 

Jennings, D. H. (1989). Some perspectives on nitrogen and phosphorus metabolism in... 

The characteristic growth-regulating auxin action of phenoxy herbicides brings about changes in water and mineral balance, in vitamin and oil content, in respiration and photosynthesis, nitrogen and phosphorus metabolism and in enzyme function (Wort, 1964b). 

Plants utilize molybdenum in minute amounts. The presence of one part per billion may eliminate molybdenum deficiency in plants. Evidence indicates that molybdenum plays a role in both nitrogen and phosphorus metabolism. Deficiency symptoms include an interveinal mottling with the leaf margins becoming brown. The leaf tissues wither leaving only the midrib and a few pieces of leaf blade and resulting in a characteristic appearance called whip tail (68). 

The organics contaminants, whose concentration is usually expressed in terms of biochemical oxygen demand (BOD), are utilized as food for the bacteria. Besides oxygen, nutrients (nitrogen and phosphorus) are also needed by the bacteria for its metabolism. The concentrations of oxygen, bacteria, organic contaminants, and nutrients, as well as other factors, have an affect on the biological treatment rate. 

Melnick, R.L. Tomaszewski, K.E. (1990) Triethanolamine. In Buhler, D.R. Reed, D.J., eds, Ethel Browning s Toxicity and Metabolism ofIndustrial Solvents, Vol. II, Nitrogen and Phosphorus Solvents, Amsterdam, Elsevier, pp. 441-450 Morin, R.J. Lim, C.T (1970) Inhibition in vitro of incorporation of [ P]-phosphate into rabbit and human endometrial phospholipids. J. reprod. Fert., 23, 456-462 Mortelmans, K., Haworth, S., Lawlor, T., Speck, W., Tainer, B. Zeiger, E. (1986) Salmonella mutagenicity tests II. Results from the testing of 270 chemicals. Environ, mol. Mutag., 8 (Suppl. 7), 1-119... 

The two characteristics, morphological differentiation and secondary metabolism, of Streptomyces are controlled by environmental conditions including nutritional conditions, such as carbon energy, nitrogen and phosphorus nutrients, and trace elements. The two biological aspects are also controlled by diffusible low-molecular-weight 7-butyrolactones called autoregulators, in addition to the environmental conditions. These... 

A proper balance of nutrients is required for plant growth. In marine systems, the stoichiometry of primary production is determined by the ratio of elements in the cytoplasm (Redfield ratio) that supports optimal metabolism of phytoplankton (Redfield, 1958). The C N P ratio is fairly constant in marine phytoplankton, and this ratio in primary producers constrains the cycling of aU elements (Elser et al., 2000). The amount and proportions of nitrogen and phosphorus available determine the amount of carbon fixed by phytoplankton. Limitation by either of these... 

Filipin inhibited anaerobic and aerobic oxidation of glucose by S. cerevisiae but had no effect on the oxidative capacity of cell-free homogenates [141]. The antibiotic reduced the dry weight of the yeast with the loss of nitrogen and phosphorus from the cell. This was the first indication that the observed effects of polyenes on fungal metabolism were a consequence of altered cellular permeability and the fungicidal effect was the result of the loss of vital cytoplasmic components. 

She also increased in body length by 5.5 cm, head circumference by 6.5 cm and chest circumference by 8.5 cm. The infant was maintained in positive nitrogen, sodium, and potassium balances throughout this period of time. The importance of balance studies is indicated by the calcium and phosphorus metabolism in this infant. Insufficient calcium and phosphorus were provided to produce positive balances until day 20. Hypophosphatemia and hypocalcemia will regularly result if phosphorus and calcium are not provided in adequate amounts in the nutritional solution daily (Ruberg et al., 1971). 

FRET-based nanosensors have been successfully used to monitor steady state levels of metabolites, nutrients, and ions in mammalian cells [74, 87], Recently FRET-based glucose, sucrose, and amino acid nanosensors have been developed to study the metabolism of glucose, sucrose, and amino acid uptake and metabolism in plant cells [80,89, 91]. The enormous potential of these nanosensors will be crucial for understanding ion (e.g., calcium), metabolite (e.g., sugars), hormone (e.g., auxins, gibberellins etc.), and nutrient (e.g., nitrogen, potassium, phosphorus) requirements and homeostasis in living plant tissues. 

Different works show that the nutritional status of certain nutrients, such as boron (B), calcium (Ca), nitrogen (N), phosphorus (P) and iron (Fe) can trigger changes in phenolic metabolism. Of these nutrients, B is attributed with a clear and significant effect on the metabolism of these secondary compounds. As we shall discuss below, the relationship between B metabolism and phenolics is complex and depends largely on the sensitivity of the plant to B deficiency or toxicity. 

As summarized in Figure 7.4, the oxidation of nitrogen, sulfur, and phosphorus is an important type of metabolic reaction in xenobiotic compounds. It can be an important intoxication mechanism... 

---