2023 Issue №4

One direction in the development of food packaging involves the use of biodegradable safe materials along with antimicrobial agents. Among the promising prescribed ingredients for biodegradable films are biopeptides with antimicrobial properties. The research goal was to develop a biodegradable food film using a synthesized antimicrobial peptide. The objects of the study were the peptide, test strains of C. albicans, Escherichia coli, and Bacillus subtilis. The confirmation of the purity and primary structure of the peptide was conducted using mass spectrometry. The antimicrobial activity of the peptide was studied using the disc diffusion method on both Gram-positive and Gram-negative bacteria. The degree of film biodegradation was determined after 1, 3, and 6 months by exposing it to microorganisms. The peptide ACSAG was synthesized, and its quantitative and qualitative composition of amino acids, sequence, and molecular mass corresponded to a known antimicrobial peptide. It was estab­lished that the synthesized peptide possesses antimicrobial activity against E. coli ATCC 25922 and B. subtilis. A composition for the biodegradable film was developed, incorporating agar-agar, glycerin, antimicrobial peptide, and distilled water. It was demonstrated that the addition of the peptide to the film composition reduces its biodegradability.

An assessment of environmental pollution in the city of Orenburg was conducted using the fluctuating asymmetry method. The common mountain ash was chosen as an environ­mental indicator. Leaf collection took place at seven points in the city with varying anthropo­genic loads. The research aimed to determine the impact of aerotechnogenic pollution on the magnitude of the fluctuating asymmetry of the leaf blade of the populations of mountain ash within the city of Orenburg. The study revealed that the leaf blades of mountain ash in urban conditions are affected by anthropogenic factors, experiencing air pollution and accumulating harmful substances. The fluctuating asymmetry method can be used as an indicator of plant development instability in urban ecosystems. Elevated environmental stress, based on the integral indicator of fluctuating asymmetry, was noted at all points except the Ural River Embankment. In this area, the growing conditions for plants were characterized as satisfacto­ry. Through pairwise correlation analysis of the examined characteristics, the closest connec­tions were found between two pairs: the width of the leaf half — the distance between the ba­ses of the first and second order veins; the distance from the base of the leaf plate to the end of the second-order vein — the angle between the main vein and the second from the base of the leaf.

A review of scientific literature describing the state and dynamics of the Eastern Baltic cod population over the past 30 years has been conducted. The Eastern Baltic cod is one of the most important commercial species in the Baltic Sea. An ecological regime shift in the early 1990s, resulting from a reduction in the frequency of large North Sea inflows, led to a de­crease in salinity and oxygen levels in the bottom layers of the deep basins of the Baltic Sea. This caused a sharp deterioration in the spawning conditions. Factors influencing the Eastern Baltic cod population and changes in the population under the influence of these factors are described. The decisive impact of North Sea inflows and their prolonged absence on the popu­lation's development, the influence of oxygen saturation levels on all life stages of cod, and the negative consequences of hypoxia for the feeding of Eastern Baltic cod are noted. Among the changes in the population, a decrease in the number of eggs in spawning areas during the peak spawning period, a reduction in the average individual sizes and weights of specimens, and a shift in the spawning peak to later dates are highlighted. The conclusion is drawn about the unsatisfactory state of the population and the impossibility of its recovery in the medium term, regardless of commercial catch rates.

The long geological history of the region, changes in marine and terrestrial deposits, and magmatic activity have determined the modern geological and geomorphological structure of the Kemerovo Region — Kuzbass, as well as the distribution of mineral resources. The aim of the study was to investigate the physico-geographical conditions of the Kemerovo Region — Kuzbass to carry out reclamation work. The main deposits of the region are located in the mountainous areas of the Kuznetsk Alatau, Salair, and Mountain Shoria. Combustible min­erals belong to a discontinuous belt in the central part of the region, where more favorable conditions for sediment accumulation are created. Kemerovo Region is characterized by di­verse geomorphological conditions and a varied climate. The main factors contributing to the climate include atmospheric circulation, relief, and vegetation. The combination of these fac­tors shapes the climatic characteristics of the region. Overall, there is a general pattern in the distribution of temperature and humidity. In the mountains of the Kuznetsk Alatau and Mountain Shoria, it is humid, but there is a deficit of warmth. The most favorable conditions have developed at the foot of the windward slopes of the Kuznetsk Alatau, where the soil is moist enough to provide warmth. Various soil coverings are formed on the territory of the Kemerovo Region, the majority of which are forest soils (brown soils and sub-brown soils, podzolic soils, gray forest soils). It has been established that based on the physico-geographical conditions in the territory of the Kemerovo Region — Kuzbass, it is advisable to carry out forestry, sanitary-hygienic, agricultural, recreational, and water management reclamation.