1.5.11 Микробиология

Norms for Arsenic’s Contamination of Soil Bezuglova O. S., Okolelova A. A. In our research we identify inaccuracy in assessment of low-degree arsenic’s contamination based on two background values to MPC, because the MPC is calculated in terms of exceeding background values higher on 2 mg/kg. We evaluate the low-degree arsenic’s contamination of soils as the difference between background values and MPC. Another informative assessment of arsenic’s accumulation in soils includes analysis of ratio of its concentration to the regional background value. In case if the regional background value is unknown, the assessment employs the ratio of arsenic’s concentration to Clark (CC). However, CC doesn’t have the classification scale. That fact reduces its benefits as useful assessment tool of soil contamination’s degree. In our article we devise CC’s classification scale that works for the assessment purposes.

Sunflower Chlorophyll Mutations Induced by N-Nitrosomethylurea and Character of Its Inheritance I. Variegated Mutants Usatov A.V. , Kolokolova N.S., Rogkova O.K., Usatova O.A., Chesnokova N.A., Fedorova M.A., Plotnikov v. G. Variegated mutants of the sunflower chlorophyll mutant collection of Southern federal university were studied. Its uniqueness consists in the fact that it was worked out on the base of one inbred line. Secondly, only one mutagen (N-nitrosomethylurea) was used for mutation inductions. Variegated mutants are characterized by leaves having white, yellow and yellow-green sectors of the various sizes and forms. Chlorophyll deficient sectors may be caused by some reasons in green plants. However, long-term researches of induced variegated mutants showed that they met the classic criteria of plastid inheritance. They are characterized by permanent somatic segregation, one-parental maternal inheritance of mutant character, defects of plastid structure and functions, presence of heteroplastid cells on the borderline between normal and mutant tissues.

This review describes the genetic characteristics of the virus, the main ways to diagnose COVID-19 infection. The SARS-CoV-2 virus is a single-stranded RNA molecule, the length of the virus genome varies from 29.8 kbp. up to 29.9 kb Comparative genomic analysis showed that SARS-CoV-2 belongs to the group of beta-coronaviruses and is very close to SARS-CoV. Initial comparative genomic analysis showed that SARS-CoV-2 is almost 79% identical to SARS-CoV and 50% identical to the MERS-CoV virus. Based on homologous modeling studies, SARS-CoV-2 has been shown to be 96.2% homologous to BatCoV RaTG13, a bat coronavirus of the genus Rhinolophus affinis. Studies to establish the origin of SARS-CoV-2 have shown that random mutation and recombination are two main sources of the genetic diversity of this virus. Recently published works show that the frequency of SARS-CoV-2 mutations is approximately the same as in the SARS-CoV genome (0.80-2.38 × 10-3 nucleotide substitutions per site per year). The most common types of mutations in the SARS-CoV-2 genome are synonymous and missense mutations. Mutations of other types were also found in the SARS-CoV-2 genome: nonsense mutations, insertions, deletions, mutations of non-coding DNA. At least seven genetically independent clones have been found that have acquired a mutation at one specific site Q677H or Q677P of the Spike virus spike protein gene.

White phosphorus is one of the most dangerous environmental pollutants. In our works, cultures of microorganisms growing in media with a content of white phosphorus up to 1 % were obtained for the first time. These cultures are unique, and they are demonstrate first ever example of the inclusion of white phosphorus in the biospheric circulation of the phosphorus element. The morphological, partly biochemical and taxonomic descriptions of cultures of microorganisms that carry out the biodegradation of white phosphorus are performed. This work is important because a unique set of characters is a characteristic of the strain. The fact of the existence of a new strain of a microorganism is established only from the moment of its accurate description. s a result of the studies, the species affiliation of the studied microorganisms was established. It was confirmed by amplification of fragments of the 16S rRNA genes (in the case of streptomycetes prokaryotes) and 18S rRNA (in the case of fungi eukaryotes), carried out by the standard PCR method, using data from the international NCBI database. New strains of Aspergillus niger and Streptomyces sampsonii species have been identified. The research results show that the biodegradation of white phosphorus can be carried out by microorganisms from various taxonomic groups. Currently, the described strains are deposited in the All-Russian collection of microorganisms and may be subject to patenting.

Environmental pollution and waste recycling remain a precarious problem of our time. One of the best approaches in solving it is biodegradation - the most natural and environmentally friendly way of destroying the waste of civilization. The presented article aims in presenting our biosphere as a territory under a reliable and vigilant protection of destructive microbes, which savor on the most toxic wastes, while highlighting the possibilities of biodegradation.  

By the results of research annotated list of 154 lichens in pine forests Ural foothills was msde. Basing on similarity of species composition, dominant species and lichen life forms, 179 pine tree sinusiums were defined in typical regional pine forests. The lichen sinusiums are found to every dynamic and geterogeneous.

Concrete, as the most popular material used in construction, is not without drawbacks directly related to its use. One of these is the process of cracking of reinforced concrete structures, leading to a decrease in the expected service life and additional costs for repairs and restoration. However, there are varieties of concrete that are capable of restoration and self-renewal. This ability is realized due to the activity of bacteria living in the thickness of concrete. The desire to imitate natural self-healing structures leads to the creation of artificial or anthropogenic forms of bioinert matter. An example of this process is the development and implementation of self-healing concrete mixes using biological components such as bacteria or their metabolites. This review considers the mechanisms of bacterial-mediated calcite reduction processes, methods for introducing living organisms into the concrete matrix, as well as the main problems and limitations that prevent the widespread use of bioconcretes.