In this Technical Note, the quantitative turbidimetric assay for determination of the bacteriolytic activity of enzymes with gram-negative bacteria is proposed. The reactivity of hen white-egg lysozyme toward gram-negative E. coli intact cells was studied. It was found that the highest lysis rate occurred at pH 8.9 in the system containing 0.03 M NaCl. The mechanism of the reaction is discussed and applied for the quantitative evaluation of the reaction rate. The proposed method enables fast, reliable, and reproducible analysis of bacteriolytic activity of lysozyme with gram-negative bacteria.

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In this paper we report the discovery of bacteriolytic activity of an immune system cytokine mediator, interleukin-2. Bacteriolytic activity of interleukin-2 was compared with a well-known bacteriolytic enzyme - chicken egg white lysozyme - by monitoring the lysis of the Gram-negative bacterium Escherichia coli, the Gram-positive coccus Micrococcus luteus, and the Gram-positive spore-forming bacillus Bacillus subtilis. It was found that interleukin-2 has greater specificity to the Gram-negative bacterium E. coli than does lysozyme. In contrast to chicken egg white lysozyme, interleukin-2 does not lyse the Gram-positive coccus M. luteus and the Gram-positive spore-forming bacillus B. subtilis. These results give a new understanding of the biological functions of interleukin-2, a regulatory protein that plays a role in oncological and infectious diseases.

In the present work the studies ofbacteriolytic factors from sheep blood plasma have been performed. Three novel enzymes have been identified and characterized. Two of them have a molecular weight 15 +/- 2 kDa and able to lyse the gram-negative Escherichia coli bacteria. The third enzyme has a molecular weight 34 +/- 4 kDa and is able to lyse both gram-negative Escherichia coli and gram-positive Micrococcus luteus bacteria. The bacteriolytic reactions have been studied for all three enzymes; particularly, pH-optima have been identified with respect to the substrate. To identify the enzymes trypsinolysis and consequent MALDI-TOF mass spectrometry studies were performed. The results were compared to data from publicly available databases, such as Swiss-Prot, NCBI, MSDB.

Bacteriophage enzyme preparations exolysin and endolysin were studied. Exolysin (a phage-associated enzyme) was obtained from tail fraction and endolysin from phage-free cytoplasmic fraction of disintegrated Salmonella enteritidis cells. A new method for purification of these enzymes was developed, and their molecular masses were determined. The main catalytic properties of the studied enzymes (pH optimum and specificity to bacterial substrates) were found to be similar. Both enzymes lyse Escherichia coli cells like chicken egg lysozyme, but more efficiently lyse S. enteritidis cells and cannot lyse Micrococcus luteus, a good substrate for chicken egg lysozyme. Similar properties of exolysin and endolysin suggest that these enzymes are structurally similar or even identical.

The authors investigated the dynamics of tannin content in the leaves of woody plants (in the maple kind) in man-made environments. Results of the study were interpreted in this work as suggestions for the public on improvement of urban area. The indicated activities are defined as passive methods -measures to reduce the effects of technogenic impact on the territory. The article presents and active ways as well -measures to eliminate the causes of man-made development.

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Purpose Currently, teachers meet difficulties when design the modern classes so that they respond to the requirements of new educational standards. Thus, the purpose of this paper is to justify the algorithm for applying the “foundations” for designing modern classes of different types and varied subject areas. Design/methodology/approach The author coordinates the “foundations” of constructing modern occupations in various subject areas on the example of lessons for children mastering the basic level of preparation and higher one. As the basis for building classes in modern conditions, the author considers the taxonomy of the pedagogical goals of B. Bloom and G. Gardner’s theory of multiple intelligences (MI). Findings The taxonomy of pedagogical goals can be one of the key foundations in the design of modern occupations of various types; the theory of MI – in the construction of classes of different subject areas. As examples for the argumentation, the author used the educational technologies of “problem education” and “project education.” Practical implications This study is a modest contribution to didactics (the science of theories and learning technologies). The results of the research actualize the work of B. Bloom and G. Gardner in the context of modern requirements for the results and content of education in general and vocational schools. The main provisions of the paper should supplement a number of such works where the solution of modern problems in education is built on the traditions and innovations balance. Originality/value The algorithm of applying the “foundations” in the modern studies’ planning can be used for lessons of various types and different subject areas. Further, research can be built in the context of interpreting the algorithm and testing its effectiveness using examples of other educational technologies.