Amino acids leaching

A variety of chemicals may be leached from the aerial portions of plants by rainwater or by fog-drip (16) including organic acids, sugars, amino acids, pectic substances, gibberellic acids, terpenoids, alkaloids, and phenolic compounds. Colton and Einhellig (17) suggested that leaf leachates of velvetleaf (Abutilon theophrasti) may be inhibitory to soybean (Glycine maxT We have recently discovered specialized hairs on the stems of velvetleaf plants which exude toxic chemicals. 

An alternative general process involves coextraction of palladium and platinum, followed by selective stripping (see Fig. 11.12). A novel amino acid extractant, made by the reaction between chloracetic acid and Amberlite LA-2, a secondary amine, is used to extract the two elements from the leach liquor. However, in the given flow sheet, no selective stripping is employed, both elements being stripped by hydrochloric acid. The resulting chloroanions are then separated by using di- -hexylsulfide to extract PdCll. ... 

FIGURE 10 Aluminum leached from glass containers by amino acids as a function of time at room temperature. Amino acid concentration 0.028 mo 1/L [53]. 

Table 34 presents the amount of DEHP leached from typical PVC infusion lines from a delivery set of 2.25 m kept at 27°C. A sample volume from 8 to 140 mL was perfused in 24 h through the lines and collected for analysis. It was possible to see that while amino acids did not promote the migration of DEHP from PVC tubing,... 

Fischer, H., Meyer, A., Fischer, K., and Kuzyakov, Y. (2007). Carbohydrate and amino acid composition of dissolved organic matter leached from soil. Soil Biol. Biochem. 39, 2926-2935. 

Sulphate is the form in which S is normally absorbed by plant roots and the reduction of sulphate for the synthesis of sulphur-containing compounds is universal for plants. Sulphur occurs in some amino acids, proteins and also in the oils of some plants such as cabbages and turnips. The S—H group is very important for the action of some enzymes and coenzymes. S is also a constituent of ferredoxins. A deficiency leads to stunting and yellowing but can be cured. A classical case of S deficiency known as tea yellows was identified in 1933 by Storey and Leach (reported in Hewitt and Smith, 1975). Sulphur deficiency leads to accumulation of amine and ammonia nitrogen, with little change in the total. 

Allochthonous DON sources from terrestrial runoff, plant detritus leaching, soil leaching, sediments, and atmospheric deposition may also represent important inputs to estuaries (Berman and Bronk, 2003). DON typically represents about 60 to 69% of the TDN in rivers and estuaries (Berman and Bronk, 2003). The major components of DON include urea, dissolved combined amino acids (DCAA), DFAA, proteins, nucleic acids, amino sugars, and humic substances (Berman and Bronk, 2003). However, less than 20% of DON is chemically characterized. 

G. Nemethy, S. J. Leach, and H. A. Scheraga, J. Phys. Chem., 70,998 (1966). The Influence of Amino Acid Side Chains on the Free Energy of Helix—Coil Transitions. 

Table VIII. 4-Amino- 3,5,6 -trichloropicolinic Acid Leached from Soil...

Muller, B., Burgstaller, W., Strasser, H., Zanella, A. Schinner, F. (1995). Leaching of zinc from an industrial filter dust with Penicillium, Pseudomonas and Corynebacterium citric acid is the leaching agent rather than amino acids. Journal of Industrial Microbiology, 14, 208—12. 

The immobilization of invertase on aluminium hydroxide (2) was one of the earliest reports of adsorption technology. The use of aminoacylase adsorbed on DEAE-Sephadex for producing L-amino acids from a racemic mixture of their corresponding ethyl esters (4) was the first industrial application of an immobilized enzyme system. The basic disadvantage of this convenient technique is that binding is weak and the enzyme slowly leaches out. However, for many purposes, this slow leakage is not an important handicap. Immobilizing enzymes by adsorption has been extensively reviewed (5, 6, 27). Some special approaches are described (1, 28-30). 

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