Burial mounds represent a challenge for microbiologists. Could ancient buried soils preserve microbiomes as they do archaeological artifacts? To investigate this question, we studied the soil microbiome under a burial mound dating from 2500 years ago in Western Kazakhstan. Two soil profile cuts were established: one under the burial mound and another adjacent to the mound surface steppe soil. Both soils represented the same dark chestnut soil type and had the same horizontal stratification (A, B, C horizons) with slight alterations. DNA samples isolated from all horizons were studied with molecular techniques including qPCR and high throughput sequencing of amplicon libraries of the 16S rRNA gene fragment. The taxonomic structure of the microbiome of the buried horizons demonstrated a deep divergence from ones of the surface, comparable to the variation between different soil types (representatives of the soil types were included in the survey). The cause of this divergence could be attributed to diagenetic processes characterized by the reduction of organic matter content and changes in its structure. Corresponding trends in the microbiome structure are obvious from the beta-diversity pattern: the A and B horizons of the buried soils form one cluster with the C horizons of both buried and surface soil. This trend could generally be designated as ‘mineralization’. Statistically significant changes between the buried and surface soils microbiomes were detected in the number of phylogenetic clusters, the biology of which is in the line of diagenesis. The trend of ‘mineralization’ was also supported by PICRUSt2 functional prediction, demonstrating a higher occurrence of the processes of degradation in the buried microbiome. Our results show a profound shift in the buried microbiome relatively the “surface” microbiome, indicating the deep difference between the original and buried microbiomes.

Cryopreservation of male gametes is one of the most important methods of assisted reproductive technologies, which allows preserving gametes for research or further use. However, the fertilizing ability of spermatozoa after cryopreservation decreases by 30-70%, which makes it urgent to search for new substances with cryoprotective properties. The review considers the main causes of cell damage during cryopreservation. The relevance of methods for assessing the formation of crystals and the physicochemical properties of cryoprotective media depending on various compositions is discussed. The problem of stabilization of the spermatozoa membrane during cryopreservation is considered. A possible solution to the problem of membrane integrity may consist in modification of the basic cryoprotective media with yolk emulsion or development of methods for saturation of the membrane phospholipid layer with cholesterol.

The soils of streets, urban parks and suburban areas were examined for yeasts in the summer of 2020 on the territory of the southern cities of Russia and the Republic of Crimea: Krasnodar, Maykop, Sochi and Simferopol. The results of this study are compared with the results of a previous study carried out in these cities in 2019. This study was conducted three months after the lockdown due to the COVID-19 pandemic, which led to a sustained decline in household waste deposition in these areas. The number of tourists visiting these southern cities decreased significantly, and the number of walkers and visitors to urban parks fell sharply. In 2020, after the decline of household waste loads, the yeast abundance was slightly but reliably higher than in 2019. A total of 30 yeast species were observed - 11 ascomycetes and 19 basidiomycetes. This was more than in 2019 and was caused by twice as many autochthonous basidiomycetous yeast species (natural core community), which were found in urban soils only after the reduction in household waste in the environment - Apiotrichum dulcitum, A. laibachii, Saitozyma podzolica Solicoccozyma terricola. And at the same time, the proportion of clinically significant (opportunistic) yeasts, Candida sake and Meyerozyma guilliermondii, was much lower in 2020 than in 2019. Thus, the observed changes in yeast communities in urban soils could be a short-time response of the microbial community to a reduction in household waste.

Variation in physical properties of soil depends heavily on freezing process during seasonal changes. Seasonal changes in cold humid regions lead to increasing of soil transformation speed. In the late autumn, soil profile is saturated with water through fallout. During winter, soil solution freezing leads to soil volume increasing due to water transition into the ice. Soil solution freezes in larger pores and the moment water flow stops, water phase transition leads to smaller pores and capillary deformation. Intensity of pore and capillary depletion will define extent of density changes during freezing. Rapidly developing urbanization process requires expansion of urban greening and tree planting, which can be successfully done by sustainable artificial soil implementation for each region, according to its climate conditions and pedogenesis. In order to observe possible porosity and structure changes in artificial soils and change rate due to freeze-thaw phenomenon, we have performed an experiment with a use of artificial soil models and then we have applied X˗Ray computer microtomography method to analyse soil pore space and its composition. As a result, we have seen significant compaction and pore diameter differentiation, as well as geometrical configuration changes.

Soil biological activity is an integral characteristic reflecting the state of soil fertility, biodiversity, and the activity of soil processes carried out by soil organisms. In Africa, studies of soil biological properties are few compared to the agrochemical research. In this paper, we present an assessment of multiple biochemical and microbiological properties of soil from an agricultural field located in the African tropical savanna. We determined basal respiration, substrate-induced respiration, C of microbial biomass, the potential activity of denitrification, nitrogen fixation activity, and estimated prokaryotic components in the soil microbial complex by quantitative PCR. Basal respiration of soils ranged from 0.77 ± 0.04 to 1.90 ± 0.23 μg C-CO2·g−1·h−1, and substrate-induced respiration ranged from 3.31 ± 0.17 to 7.84 ± 1.04 μg C-CO2·g−1·h−1. The C reserves of microbial biomass averaged 403.7 ± 121.6 μg C·g−1 of soil. The N2O emission from the upper layer on average amounted to 2.79 ng N-N2O·g−1·day−1, and the potential denitrification activity reached 745 ± 98 ng N-N2O·g−1·h−1. The number of copies of bacterial genes varied from (0.19 ± 0.02) × 108 to (3.52 ± 0.8) × 108 copies·g−1, and of archaea—from (0.10 ± 0.01) × 107 to (0.29 ± 0.01) × 107 copies·g−1 of soil. These results were in good agreement with the studies in other seasonally wet tropical regions: the biological activity was relatively low. The difference between biological indicators of the experimental field and the reference profile were insignificant except for nitrogen loss, which was higher in the ploughed field. Biological indicators strongly varied in space; we explained their heterogeneity by non-uniform management practices in the course of agrochemical field experiments in the past. The use of organic fertilisers may cause the release of climatically active gases due to intensive microbial respiration and denitrification, but the intensity of emission would strongly depend on the cultivation and management method.

Sixteen variants of test systems (two-site sandwich and competitive enzyme-linked immunosorbent assay (ELISA)) were studied to determine the concentration of microfungi, some of which are known opportunistic pathogens for humans, in soil extracts. The correlation of the amount of fungal biomass (the length of the growing mycelium) with the concentrations of antigens detected by the two-site sandwich ELISA method and the competitive ELISA method was evaluated. It has been shown that the methods are highly effective in the case of long incubation (more than 5 days) of soil samples and are ineffective for short-term incubation, because there was no correlation between hypha length and antigen concentration during the first day of cultivation. The perspectivity of ELISA methods for the detection of some soil microfungi from genera Aspergillus (Asp. flavus, Asp. fumigatus, Asp. niger), Fusarium (F. solani, F. poae), and others (Alternaria alternata, Phoma lingham, Mucor hiemalis) was shown. The competitive ELISA method was more efficient than two-site sandwich ELISA.

Еxam of the activity of peritoneal macrophages, NO-dependent state and mechanisms of free radical processes in normal pregnancy and in the background of the experimental disturbance of the utero-placental circulation (DUPC) was done with using of white rats. With the introduction of L-NAME and DUPC in serum observed similar changes in the form of lower levels of total nitrate and nitrite, increasing free radical processes. Activity of peritoneal macrophages varies in the opposite way L-NAME significantly increases her, and DUPC decreases. When combined action of increased production of nitric oxide formation and nitrotirozine that under these conditions plays a protective role by providing adaptation impaired feto-placental blood flow to the needs of the fetus, the activity of macrophages corresponds to the intact rats.

В статье приведены комментарии к трем проектам федеральных стандартов аудиторской деятельности (ПСАД), подготовленных в соответствие с международными стандартами аудита (МСА) 700, 705, 706.

An oxidative stress resistance in Paecilomyces lilacinus strain from Chernobyl Atomic Energy Station (ChAES) as well as in P. lilacinus strains from zones with control level of radioactive pollution has been studied. It was shown that radial growth rate of the colony of the ChAES strain in a range of glucose concentrations 0.002%; 0.2%; 0.5%; 1.0% showed maximum on the medium with 0.2% glucose. It was 1.5 times higher than growth rate of the control strains. Adaptation slowdown reaction has been found as a result of the first 10-30 min H2O2 treatment most profound in the ChAES (No 1941) strain. Under 10(-3) mol/l H2O2 growth of No 1941 resumed with 20% loss in growth rate. Cessation of growth of the control strain (No 10) was observed under these conditions. It has been shown that in the strain from ChAES zone adaptation to low glucose content in the medium (0.2%) was coupled with an increased resistance to oxidative stress.

The mycological properties of soil can offer information about ancient human–landscape interaction, including urbanization. This preposition has been confirmed in our study of the habitation deposits in the medieval Russian settlements (eighth to fourteenth centuries A.D.).

Контактная информация:Юрьева Элеонора Александровна, доктор медицинских наук, профессор,главный научный сотрудник лабораторииобщей патологии Московского научноисследовательского институтапедиатрии и детской хирургииРосмедтехнологийАдрес: 125412, Москва, ул. Талдомская, д. 2, тел. (495) 4880064Статья поступила 02.09.2007 г.,принята к печати 15.10.2007 г.