卷 74, 编号 1 (2019)

The work is based on the results of long-term studies on phytoplankton and zooplankton in sodasaline lakes of the Uldz Gol-Torey basin (southeastern Trans-Baikal region). The unstable level regime of steppe lakes, due to climate fluctuations, leads to changes in the morphometric and hydrochemical regime of the lakes, and, as a consequence, to transformation of the plankton community. The goal of this work is to identify and analyze environmental factors that determine the structure of planktonic biocenoses in mineral lakes at different water-fill phases. According to statistical analysis of auxiliary models based on the redundancy analysis (RDA), the significance factors were mineralization and pH in the transgressive water-fill phase and pH in the regressive phase. Schematic drawings of interrelationships within the plankton community are constructed on the basis of the correlation matrix. There were nine interrelated components in the plankton natural associations in the high-water period and only five components at a low-water level. Chlo-rophyta was found to be a basic constructive element of the plankton community regardless of the water level. Euglenophyta, Bacillariophyta, and Cladocera were the second most significant elements in the structural organization during the full-water period and Charophyta, Dinophyta, Rotifera, and Copepoda were during the water-short period.

The life cycle of cyanobacteria Dolichospermum flos-aquae causing the blooming of waters of the boreal zone is studied. The mass propagation of the D. flos-aquae in the plankton stage occurs due to their ability to realize high biotic potential, defined by the combination of features developed during evolution, which the other partners of the plankton community lack. These include: adaptation to a certain growth temperature; low demand for nutrients; nitrogen fixation and intracellular accumulation of phosphates; and the ability of trichomes to migrate, allowing them to occupy the optimal parts of the euphotic zone for photosynthesis. It is established that the trichomes of D. flos-aquae consist of heterocysts and vegetative cells of different maturity, generosity, and activity during the planktonic stage, and their ratio changes throughout the life cycle of microorganisms. It is believed that the primary and secondary metabolites released by D. flos-aquae into the medium take part in the regulation of their own population growth, including cell destruction at the final stage of blooming, akinetes formation, and the simultaneous suppression in propagation of community partners. With the dominance of one species, the released toxic metabolites increase in years with an anticyclone type of weather, resulting in the reduction of species diversity and the simplification of the biotic community structure.

Pairwise alignment of amino acid sequences is the basic tool of bioinformatics, which is widely used both independently and within numerous more complex methods. The effectiveness of this tool critically depends on the scoring function used, which consists of a substitution matrix and gap penalties. In this work, amino acid substitution matrices for the superfamily of microbial rhodopsins (RHOD) were constructed and analyzed and then compared with a set of general-purpose matrices (BLOSUM, VTML, PFASUM). It was shown that all matrices allow constructing alignments of microbial rhodopsin sequences of almost the same quality, but only BLOSUM and VTML matrices and their linear combinations with RHOD matrices allow revealing homology between microbial rhodopsins and heliorhodopsin.

The anthropogenic salinization of inland waters and its effect on freshwater biota are current environmental problems. This salinization leads to changes in the natural environment that are ecologically undesirable and not indifferent to humans. The widespread use of agents for road deicing has become one of the three most important factors of anthropogenic salinization of fresh water (along with agricultural activities and mining) in countries with temperate and cold climate. Today, the main components of these agents are Na and Ca chlorides—cheap and easily available natural materials. Their mixture with sand, used in deicing practice, is usually stored in bulk in special open-air areas all year round. The impact of atmospheric precipitation makes this mixture a source of salinization of the surrounding soils and waters. In 2015, 2016, and 2018, the salinity of inland waters was recorded near the long-term open storage of antiicing agents in Kaluga oblast. The anthropogenic nature of salinization of the investigated water bodies is established. The main components of salinization of water bodies in the study area are Na and Ca chlorides. The maximum degree of salinization in the studied conditions is 4‰ (ppm); the degree of salinity depends on the distance of the water body from the road-salt storage. The influence of anthropogenic salinity on dragonflies, mainly of the species Coenagrion puella L., is studied. It is found that the negative effect of high water salinity is expressed only in the slowdown of the development of individuals with a high level of fluctuating asymmetry, the number of which in the population is not determined by water salinity. High water salinity leads to changes only in the timing of emergence of imagoes with high FA. It is assumed that dragonflies as a mass object of freshwater biota are obviously not significantly exposed to anthropogenic salinization.