External Chemical Factors Research Articles

The influence of chemical factors on the metal-binding capacity of non-starch polysaccharides

The article considers not only the possibility of non-starch polysaccharides to bind heavy metal ions, but the factors affecting this ability are determined. The ability of some non-starch polysaccharides to form complexes with heavy metal ions significantly depends on the structure, structure and external chemical factors. Considered polysaccharides are: pectin, chitosan and sodium alginate. Considered factors: temperature and pH.

New method of complex photo-fluorescent microbiotesting

The biotesting procedure is described, which provides for recording changes in the intensities of elastic light scattering, light absorption and intrinsic photofluorescence of the protein component, as well as determination of concentration and structuring coefficients of the genomic component of samples with viable unicellular test organisms, incubated in a liquid nutrient medium in the presence and absence of various external chemical factors. The results of the analysis using this technique of the antibiotic activity of cations of various metals are presented. It is shown that using this technique can be much more rapid, objectively and comprehensively than using standard visual microbiotesting methods, to assess the effect on reproduction rate, metabolic activity and genome structure of test organisms of samples of various products, wastes, etc.

New Method of Integrated Photofluorescence Microbiotesting.

A biotesting procedure that makes it possible to record the changes in the intensities of elastic light scattering, light absorption, and intrinsic photofluorescence of the protein component, as well as the determination of the concentration and structuring coefficients of the genomic component, of the samples with viable unicellular test organisms incubated in a liquid nutrient medium in the presence and absence of various external chemical factors, is described. The results of the analysis of the antibiotic activity of various metal cations with the use of this technique are presented. This technique is much more rapid, objective, and comprehensive for the assessment of the effect on the reproduction rate, metabolic activity, and genome structure of the test organisms from the samples of various products, wastes, etc. than standard visual microbiotesting methods.

FACTORS AFFECTING ROOT FORMATION OF PHASEOLUS VULGARIS

The successful rooting of leafy cuttings involves three physiologically distinct processes: initiation of root primordia; development of true roots from these initials; and maintenance of the cutting as an excised organ during the rooting. The first of these, where it does not take place spontaneously, can be brought about in many plants by treatment with auxin. The second (outgrowth of the roots) involves the formation of cell-wall and protoplasm; it therefore requires the supply of carbohydrates and nitrogenous materials, together with such special substances as may be needed for root growth. Normally all of these materials would be supplied from the leaves or from storage in the stem. Too little attention has been paid up to now to the third process, the maintenance of the cutting, which, in view of the special conditions that obtain when leaves are severed from the plant, is of great importance. Thus, as pointed out by Chibnall (4), the detached leaf of many plants, including Phaseolus, undergoes a rapid and extensive proteolysis. The present experiments were, therefore, designed to shed some light on the second and third of these processes. It was our intention to study the influence of nutrition, especially nitrogen nutrition, and other external chemical factors on the rooting and maintenance of leafy herbaceous material. Since internal factors must also be considered in such a study, attention was paid to the r?le of auxin and also to the separate r?les of the leaves and the stem.