Биология

The combined effect of coatings based on nanoparticles of metals Ag, Au, ultraviolet (365 nm, UVR) and infrared (808 nm, IRR) radiation on Staphylococcus aureus 209 P was studied. Decrease in numbers was shown by 2% in the case of silver coatings and by 8% in the case of gold coatings after 1 h incubation. However, exposure of the IRR to bacterial suspensions caused the death of 43% of the population after 5 min, 86% of the population after 30 min.

The structure of the cell surface reflects the functional state of the bacterium as a whole. The presence of specific features of cells affects the biophysical characteristics of their surface: charge, free energy and hydrophobicity. The interaction of bacteria with biomolecules and particles is also related to these surface characteristics. The aim of our work was to study the function of F. tularensis 15 NIIEG cells under cultivation under stress using electro-optical (EO) monitoring.

The practical value of the coefficient of commercial replenishment of fish stocks, due to the variety of its use in different areas of fisheries research, design work, restoration activities, and management decisions was highlighted. For many species of fish there is no information on the indicator under consideration. Catfish, one of the valuable commercial species, is included in this category.

At the present stage of the studies only Ixodidae ticks can be classed by the types of foci, being the main blood-sucking vectors of the tularemia agent. Other blood-sucking arthropods, considering the species abundance and wide-spread occurrence and certain habitat versatility, can be tularemia vectors in several or even in all types of foci. These are the following: primarily, gamaside and argasid ticks, as well as bloodsucking insects.

The results of studying the morphogenesis of monocarpic escape during the seasonal development of Hosta sieboldiana are presented. It is shown that organ-forming processes of generative organs occur in the spring-summer vegetation of the shoot. Generative shoot is formed at 75–76 of days to flowering. Established, that the cone of increase of the escape differentiates intrarenal II to VIII stages of organogenesis. The flowers are laid in the acropolis direction. Duration of flowering was 25–38 days, fruiting 29–30 days.

In our study on mice with an injection model of Alzheimer’s disease (AD), beta-amyloid detection in the brain tissue was evaluated using immunohistochemistry and confocal analysis. An accumulation of toxic protein was shown in different areas of the brain, predominantly in the cortex and in the hippocamp (place of beta-amyloid injection). Neurofunctional tests were conducted to confirm the development of AD.

In the rivers of the Yenisei basin, benthic invertebrates play a major role in feeding most valuable Siberian fish species. This report presents advanced material on zoobenthos of the river Kan (one of the major tributaries of the Yenisei in its middle course). Litho-psammo-rheophilic biocenosis of benthic invertebrates was the most developed, 99 species and forms were recorded there. The total number of zoobenthos was formed from mayflies, caddisflies and chironomids; biomass – from caddisflies and mayflies.

The present work is a continuation of the inventory of the coleopterofauna of the water-terrestrial ecotones of the nature monument «Rasskazan’ Lake» Balashov district of Saratov province, which began in 2017. The study concerned the spring fauna of the period of occurrence of the Khoper river in low water after floods and the beginning of the stagnation of the lake water level.

The article considers the issue of studying the steppe vegetation of the Khvalynsky National Park from the standpoint of ecologophytocenotic and ecologo-floristic approaches to the classification of vegetation. New associations Alysso tortuosi-Artemisietum salsoloidis Lysenko ass. nov. hoc loco, Euphorbio glareosae-Festucetum valesiacae ass. nov. hoc loco, Artemisio marschallianae-Stipetum pennatae Lysenko ass. nov. hoc loco, Astragalo varii-Bromopsietum inermis Lysenko ass. nov. hoc loco, Astragalo albicaulis-Stipetum lessingianae Lysenko ass. nov.

The article presents the results of studying the dynamics of the formation of the root and above-ground mass of spring soft wheat, virgin and fallow cenoses under the conditions of 2012 and 2018. The dynamics of the placement of the root system of cultivated plants in the grain-pair crop rotation over the vegetation phases was revealed. It was shown that spring wheat forms the secondary root system during the growing season only in favorable meteorological conditions, mainly within the 0–50 cm layer (74%).