Biotechnologia Acta

7-19

Authors: Leonenko N. S., Leonenko O. B.

The review summarizes the literature data on the assessment of the toxic effects of nanoscale particles at various concentrations and routes of entry into the body. The toxic effect of nanoobjects is more complex and diverse in comparison with the effect of traditional toxicants (heavy metals, organic solvents, poisonous substances, etc.). Despite the growing amount of data, there are no unified approaches to studying the toxic effects of nanoscale particles. This requires the development of specific procedures for their toxicity assessing.

31-40

Authors: Klyuchko O. M.

The aim of the work was to analyze the range of mathematical methods and to choose the most prospective ones from the point of view of application in biology and medicine. After analyzing of approximately 200 current publications, a list of respective methods was completed. This list includes both the most recent, intensively developed methods as well as traditionally used ones — mathematical statistics, stochastic methods, regression analysis, and others. From the first group the methods of cluster analysis, artificial neural networks and image processing were subdivided. A description of each of these methods and examples of their application in practice are given. A separate group is dedicated to complex modern works, in which the problems requiring the complex application of several methods are present. In conclusions a brief assessment of the methods of cluster analysis, artificial neural networks, image processing methods are given as well as recommendations for their practical application.

50-56

Authors: Levandovskiy L. V., Myhailyk V. S.

This work objective is to find the technological conditions for the intensification of yeast growth in the gradient-continuous yeast cultivation process. Experiments on four sequential yeast chemostats (connected into a battery) demonstrated broad possibilities to influence the metabolic activity of yeast and the alcohol production depending on the content of molasses introduced into the second, third and fourth yeast generators. Adding the molasses according to the 3:2:1 scheme in quantities, which are sufficient to achieve the initial concentration of solids of 26.5 g/100 cm3 to the end of the process resulted in high accumulation of yeast in the medium (up to 99 g/dm3). It is demonstrated that the highest ratio of economic effect of biomass synthesis from molasses sugars (88 g/100 g) is achieved when molasses is added according to the 1:2:2.5 scheme and the initial solids concentration in the medium is near 12 g/100 cm3.

65-71

Authors: Malynovska I. M.

The aim of the work was to determine the possibility of using the number and activity of Azotobacter cells and melanin-synthesizing micromycetes as indicators of gray forest soils of different types (fallow, extensive and intensive agrosoil) pollution with heavy metal ions. For this purpose, there were used laboratory-analytical, microbiological and statistical methods. As a result of research of increasing doses of heavy metals (zinc + lead) influence on the number of microorganisms in the gray forest soils it was found that the number and activity of Azotobacter and the number and part of melanin-synthesizing micromycetes in their total number may be fit into indicators of pollution with heavy metals. Azotobacter cells activity index may be considered indicative at contamination levels of 5-100 of maximum permissible concentrati{spoiler title=Скрытый текст}{/spoiler}on in the absence of vegetation, at contamination levels of 10–100 – for soils with phytocenosis. The number and proportion of melaninsynthesizing micromycetes in total guantity may serve as diagnostic sign of gray forest soils pollution with high doses of heavy metals, but only for the period of contamination up to 2 years. It was shown that nature of the effect of heavy metals on the number of microorganisms of indicative groups depended on the presence of plants in the monitoring system, on doses of heavy metals, on the term of contamination and on the type of soil usage.