Assessment of the Impact of No-Till and Conventional Tillage Technologies on the Microbiome of Southern Agrochernozems

Eurasian Soil Science - Quantitative characteristics of microbial communities in southern agrochernozems of the Stavropol region managed with the use of no-till technology and moldboard plowing...     

Actinomycetal complex of light sierozem on the Kopet-Dag piedmont plain

The population density of actinomycetes in the samples of light sierozem from the Kopet Dag piedmont plain (75 km from Ashkhabad, Turkmenistan) reaches hundreds of thousand CFU/g soil. The actinomycetal complex is represented by two genera: Streptomyces and Micromonospora. Representatives of the Streptomyces genus predominate and comprise 73 to 87% of the actinomycetal complex. In one sample, representatives of the Micromonospora genus predominated in the complex (75%). The Streptomyces genus in the studied soil samples is represented by the species from several sections and series: the species of section Helvolo-Flavus series Helvolus represent the dominant component of the streptomycetal complex; their portion is up to 77% of all isolated actinomycetes. The species of other sections and series are much less abundant. Thus, the percentage of the Cinereus Achromogenes section in the actinomycetal complex does not exceed 28%; representatives of the Albus section Albus series, Roseus section Lavendulae-Roseus series, and Imperfectus section belong to rare species; they have been isolated not from all the studied samples of light sierozem, and their portion does not exceed 10% of the actinomycetal complex.     

Distribution of yeast complexes in the profiles of different soil types

The number and taxonomic structure of the yeast complexes were investigated in the full profiles of the soddy-podzolic soil (Central Forest State Nature Biosphere Reserve), dark gray forest soil (Kaluzhskie Zaseki Reserve), and chernozem (Privolzhskaya Forest-Steppe Reserve). In all these soils, the number of yeasts was maximal (10⁴ CFU/g) directly under the litter; it drastically decreased with the depth. However, at the depth of 120–160 cm, the number of yeasts significantly increased in all the soils; their maximum was found in the illuvial horizon of the soddy-podzolic soil. Such a statistically significant increase in the number of yeasts at a considerable depth was found for the first time. Different groups of yeasts were present in the yeast communities of different soils. The species structure of yeast communities changed little in each soil: the same species were isolated both from the soil surface and from the depth of more than 2 m. The results showed that yeasts could be used for soil bioindication on the basis of specific yeast complexes in the profiles of different soil types rather than individual indicative species.     

Microbial Communities of Interglacial and Interstadial Paleosols of the Late Pleistocene

Eurasian Soil Science - The taxonomic structure of microbial communities in the Late Pleistocene paleosols of different ages in the Central Russian Upland formed under contrasting climatic...     

Combined Application of Xymedon Hydrochloride with Rabies Vaccine on the Background of Immunosupression

The effect of xymedon hydrochloride on the immune response of rabbits immunized with the rabies vaccine prepared from strain Shchelkovo-51 under the influence of immunosupression induced by cyclophosphamide has been studied. Xymedon hydrochloride was injected at a dose of 5 mg kg body weight in a volume of 1 cm³ twice a day in combination with the rabies vaccine. In addition, the immune response higher level of 1: 12800 was observed in the immunosupressed animals compared to 1: 6400 in the control animals immunized without the immunostimulant. At 6 months after vaccination, the antibody concentration of 1: 93.75 ± 44.68 remaining below the protective level was recorded, which indicated the weakness of the humoral link in the immune system. The counts of T- lymphocytes, B-lymphocytes, T-helpers, and T-suppressors in the blood of the immunesuppressed rabbits immunized with the rabies vaccine in combination with xymedon hydrochloride increased 3.2-fold, 1.9-fold, 7.7-fold, and 22.0-fold, respectively, when compared with the reference values. Therefore, the protective effect was followed by increasing the antigeninduced and spontaneuous lymphocyte proliferation, the numbers of T-helper cells and T lymphocytes exhibiting the cytotoxic and suppressive activity, and the virus-specific neutralizing antibody titers in cases wherein the Shchelkovo-51 vaccine in combination with xymedon hydrochloride was administered. It should be reasonable to apply the two-step rabies vaccination with the use of the immunostimulant, in particular, xymedon hydrochloride, to ensure the adequate immune response in immunodeficient animals.     

Ecological and taxonomic features of actinomycetes complex of the soils of the Lake Elton region

Ecological and taxonomic characteristics of the actinomycete complex of solonchak soils and light chestnut soils in the Lake Elton region have been presented. Data on the abundance and taxonomic structure have confirmed the ecological importance of actinomycetes in soils with evident signs of salinity.     

Bacterial complexes of a high moor related to different elements of microrelief

The analysis of bacterial complexes, including the number, taxonomic composition, physiological state, and proportion of ecological trophic groups was performed in a high moorland related to different elements of the microrelief. The abundance of bacteria, their ability for hydrolysis of polymers and the share of r-strategists were found to be higher in the sphagnum hillocks than on the flat surfaces. The total prokaryote biomass was 4 times greater in the sphagnum samples from microhighs (hillocks). On these elements of the microrelief, the density of actinomycetal mycelium was higher. Bacteria of the hydrolytic complex (Cytophaga and Chitinophaga genera) were found only in microhigh samples.     

Profile analysis of microbiomes in soils of solonetz complex in the Caspian Lowland

The taxonomic structure of the microbiota in two associated soils—solonetz on a microhigh and meadow-chestnut soil in a microlow—was studied in the semidesert of the Caspian Lowland. A highthroughput sequencing of the 16S rRNA gene was used for the soil samples from genetic horizons. A considerable reduction in the bacterial diversity was found in the lower horizons of the solonetz and compact solonetzic horizon with a high content of exchangeable sodium. In the meadow-chestnut soil, the microbial diversity little decreased with the depth. In both soils, a portion of archaea from the Thaumarchaeota group also decreased in the deeper horizons. In the soil horizons with the lower total bacterial diversity, a share of proteobacteria of the Enterobacteriaceae, Pseudomonadaceae, and Sphingomonadaceae families became higher. The difference between the structure of the microbial population in the solonetz and meadow- chestnut soil can be first explained by the different water regimes and soil consistence.