Sulfur content in needles of cedar (Pinus sibirica Du Tour) and siberian fir (Abies sibirica Ledeb.) of the Southern Baikal Region: Influence of industrial emissions

The paper presents the results of studying the sulfur content in the needles of cedar and Siberian fir of the Southern Baikal Region, carried out in the 2014–2015 period. The research aims to determine whether Baikal Pulp and Paper Mill (BPPM) are the primary stress factor of abiotic nature, which leads to the degradation of cedar and Siberian fir stands in the Southern Baikal Region. The authors have determined that the primary factor is the long-term impact of the emission of pollutants from heat power companies in the Irkutsk Region, as indicated by numerous studies using mathematical modeling methods. The research demonstrates that the assimilation organs of the cedar are more sensitive to the effects of sulfur dioxide compared to the needles of Siberian fir. Therefore, cedar needles can be considered as a more sensitive indicator of atmospheric pollution with sulfur dioxide. The authors have established that the primary source of contamination of Siberian fir needles is the SO₂ emission from the heat and power enterprises of the Irkutsk Region and not the emission of sulfur-containing compounds of the BPPM. The authors found that in the period from 2010 to 2019, the total SO₂ emissions from large industrial companies were an order of magnitude lower than the volumes of SO₂ emissions from heat power companies in the Irkutsk Region. These emissions will provoke a further deterioration in the state of the boreal forests of the Southern Baikal Region

Water Quality, Toxicity and Diversity of Planktonic and Benthic Cyanobacteria in Pristine Ancient Lake Khubsugul (Hövsgöl), Mongolia

For the first time, microcystin-producing cyanobacteria have been detected in Khubsugul, which is ancient, pristine and one of the world’s largest lakes. The microcystin synthetase genes belonged to the genera Nostoc, Microcystis and possibly Snowella spp. No microcystins were found in the water of the lake. Using the HPLC-HRMS/TOF, five microcystin congeners were identified in biofilms from stony substrates sampled in the coastal zone. The concentration of microcystins in biofilms was low: 41.95 µg g−1 d. wt. by ELISA and 55.8 µg g−1 d. wt. using HPLC. The taxonomic composition of planktonic and benthic cyanobacterial communities was determined by means of microscopy and high-throughput sequencing of 16S rDNA amplicons. Nostocales cyanobacteria dominated benthos of Lake Khubsugul and Synechococcales—plankton. The abundance of cyanobacteria was low both in plankton and benthos; there was no mass development of cyanobacteria. Hydrochemical and microbiological analyses showed that the water in the lake was clean; the number of faecal microorganisms was significantly below the acceptable guideline values. Hydrochemical and hydrophysical parameters, and the concentration of chlorophyll a, were low and within the range of values recorded in the 1970s to 1990s, and corresponded to the oligotrophic state of the lake. There were no signs of anthropogenic eutrophication of the lake and no conditions for the cyanobacterial blooms

Dates and Rates of Tick-Borne Encephalitis Virus—The Slowest Changing Tick-Borne Flavivirus

We evaluated the temporal signal and substitution rate of tick-borne encephalitis virus (TBEV) using 276 complete open reading frame (ORF) sequences with known collection dates. According to a permutation test, the TBEV Siberian subtype (TBEV-S) data set has no temporal structure and cannot be applied for substitution rate estimation without other TBEV subtypes. The substitution rate obtained suggests that the common clade of TBEV (TBEV-common), including all TBEV subtypes and louping-ill virus (LIV), is characterized by the lowest rate (1.87 × 10−5 substitutions per site per year (s/s/y) or 1 nucleotide substitution per ORF per 4.9 years; 95% highest posterior density (HPD) interval, 1.3–2.4 × 10−5 s/s/y) among all tick-borne flaviviruses previously assessed. Within TBEV-common, the TBEV European subtype (TBEV-E) has the lowest substitution rate (1.3 × 10−5 s/s/y or 1 nucleotide substitution per ORF per 7.5 years; 95% HPD, 1.0–1.8 × 10−5 s/s/y) as compared with TBEV Far-Eastern subtype (3.0 × 10−5 s/s/y or 1 nucleotide substitution per ORF per 3.2 years; 95% HPD, 1.6–4.5 × 10−5 s/s/y). TBEV-common representing the species tick-borne encephalitis virus diverged 9623 years ago (95% HPD interval, 6373–13,208 years). The TBEV Baikalian subtype is the youngest one (489 years; 95% HPD, 291–697 years) which differs significantly by age from TBEV-E (848 years; 95% HPD, 596–1112 years), LIV (2424 years; 95% HPD, 1572–3400 years), TBEV-FE (1936 years, 95% HPD, 1344–2598 years), and the joint clade of TBEV-S (2505 years, 95% HPD, 1700–3421 years) comprising Vasilchenko, Zausaev, and Baltic lineages

Acoplanarity, Aromaticity, Chirality, and Helical Twisting Power of Chlorin e6 13(N)-Methylamide-15,17-dimethyl Ester Complexes: Effect of a Metal

The experimental and theoretical study of the influence of metal complexing on geometry, aromaticity, chirality, and the ability to twist the nematic phase by complexes based on modified natural chlorin e6 was carried out. The geometry optimization of the chlorin e6 13(N)-methylamide-15,17-dimethyl ester (MADMECl) and its Zn, Cu, and Ni complexes by DFT (CAM-B3LYP/6–31 G(d,p) functional) method was performed. Based on these calculations, the acoplanarity degree of the macrocyclic ligand and the distortion energy of its dianion were estimated, which allowed the arrangement of the MADMECl complexes in the series Ni > Cu > Zn. Aromaticity was evaluated using the NICS criterion (nuclear independent chemical shift). An increase in the degree of aromaticity of the macrocycle upon complex formation was established. At the same time, the aromaticity of the inner conjugation contour corresponds to the same series as the acoplanarity, while the outer π-delocalization is characterized by the reverse sequence. An experimental evaluation of the electron circular dichroism of the Soret and the Q-bands, as well as the g-factor of dissymmetry, was carried out. The growth of these parameters with an increase in the degree of acoplanarity and aromaticity of the internal conjugation contour was determined. The induction of helical phases in mixtures of nematic liquid crystals (LCs) based on cyanobiphenyls and MADMECl macrocyclic metal complexes was studied by polarization microscopy, and the clearance temperatures and helix pitch of the mesophases were measured. A strong effect of the metal on the phase transition temperature and helical twisting power was established

Genomic Determinants Potentially Associated with Clinical Manifestations of Human-Pathogenic Tick-Borne Flaviviruses

The tick-borne flavivirus group contains at least five species that are pathogenic to humans, three of which induce encephalitis (tick-borne encephalitis virus, louping-ill virus, Powassan virus) and another two species induce hemorrhagic fever (Omsk hemorrhagic fever virus, Kyasanur Forest disease virus). To date, the molecular mechanisms responsible for these strikingly different clinical forms are not completely understood. Using a bioinformatic approach, we performed the analysis of each amino acid (aa) position in the alignment of 323 polyprotein sequences to calculate the fixation index (Fst) per site and find the regions (determinants) where sequences belonging to two designated groups were most different. Our algorithm revealed 36 potential determinants (Fst ranges from 0.91 to 1.0) located in all viral proteins except a capsid protein. In an envelope (E) protein, most of the determinants were located on the virion surface regions (domains II and III) and one (absolutely specific site 457) was located in the transmembrane region. Another 100% specific determinant site (E63D) with Fst = 1.0 was located in the central hydrophilic domain of the NS2b, which mediates NS3 protease activity. The NS5 protein contains the largest number of determinants (14) and two of them are absolutely specific (T226S, E290D) and are located near the RNA binding site 219 (methyltransferase domain) and the extension structure. We assume that even if not absolutely, highly specific sites, together with absolutely specific ones (Fst = 1.0) can play a supporting role in cell and tissue tropism determination

Antiradical Activity of Porphyrins with a Diisobornylphenol Fragment at the Macrocycle Periphery

This article focuses on the antiradical activity of a number of 2,6-diisobornylphenol-porphyrin conjugates with various spacers between the porphyrin and phenolic fragments in the model reaction of ethylbenzene oxidation initiated by azoisobutyric acid dinitrile. The study has shown that the electronic effects of the groups directly related to the 2,6-diisobornylphenol fragment exert the predominant influence both on the reactivity of the phenolic hydroxyl group in interaction with free radicals and on the antiradical activity of the molecule as a whole. The antiradical activity of the molecule is generally less affected by the nature of the substituents in the porphyrin macrocycle, mainly due to a change in the stoichiometric inhibition coefficient in the presence of relatively easily oxidizable groups. It was found that the length of the spacer between the porphyrin and phenolic fragments does not affect the antiradical activity of the conjugate

Metagenomic Analysis of Virioplankton from the Pelagic Zone of Lake Baikal

This study describes two viral communities from the world’s oldest lake, Lake Baikal. For the analysis, we chose under-ice and late spring periods of the year as the most productive for Lake Baikal. These periods show the maximum seasonal biomass of phytoplankton and bacterioplankton, which are targets for viruses, including bacteriophages. At that time, the main group of viruses were tailed bacteriophages of the order Caudovirales that belong to the families Myoviridae, Siphoviridae and Podoviridae. Annotation of functional genes revealed that during the under-ice period, the “Phages, Prophages, Transposable Elements and Plasmids” (27.4%) category represented the bulk of the virome. In the late spring period, it comprised 9.6% of the virome. We assembled contigs by two methods: Separately assembled in each virome or cross-assembled. A comparative analysis of the Baikal viromes with other aquatic environments indicated a distribution pattern by soil, marine and freshwater groups. Viromes of lakes Baikal, Michigan, Erie and Ontario form the joint World’s Largest Lakes clade

Comparison of bacterial diversity and species composition in three endemic Baikalian sponges

Baikalian sponges are unique organisms with many species harboring symbiotic microbes that produce novel bioactive compounds. To investigate bacterial diversity of three species of Baikalian sponges, specimens of Lubomirskia baicalensis, Baikalospongia intermedia and Swartschewskia papyracea collected from Lake Baikal were processed by pyrosequencing. We found differences in the species composition and diversity in bacteria among these sponges. Cyanobacteria accounted for the highest proportion and the second group was Proteobacteria in three sponges. The bacterial communities in B. intermedia and L. baicalensis were highly similar but less similar to the bacterial community associated with S. papyracea. Diversity of the bacterial community in S. papyracea was higher than in L. baicalensis and B. intermedia. In particular, the relative abundance of Actinobacteria was higher in S. papyracea. Bacterial species in phyla Acidobacteria and Gemmatimonadetes were only found in S. papyracea.Sponge-symbionts have the ecological important functions and produce a diverse pharmacological metabolites. Bacteria associated with freshwater sponges have been much less studied. Our study describes diversity of bacteria in Baikalian sponges, specially, those of S. papyracea for the first time. We provide additional knowledge into freshwater sponge-associated microbiota

Bacterioneuston in Lake Baikal: Abundance, Spatial and Temporal Distribution

An aquatic surface microlayer covers more than 70% of the world’s surface. Our knowledge about the biology of the surface microlayer of Lake Baikal, the most ancient lake on Earth with a surface area of 31,500 km2, is still scarce. The total bacterial abundance, the number of cultured heterotrophic temporal bacteria, and the spatial distribution of bacteria in the surface microlayer and underlying waters of Lake Baikal were studied. For the first time, the chemical composition of the surface microlayer of Lake Baikal was determined. There were significant differences and a direct relationship between the total bacterial abundance in the surface microlayer and underlying waters of Lake Baikal, as well as between the number of cultured heterotrophic bacteria in studied water layers in the period of summer stratification. In the surface microlayer, the share of cultured heterotrophic bacteria was higher than in the underlying waters. The surface microlayer was characterized by enrichment with PO43−, total organic carbon and suspended particulate matter compared to underlying waters. A direct relationship was found between the number of bacteria in the surface microlayer and environmental factors, including temperature, total organic carbon and suspended particulate matter concentration

Polymorphism of SERF2, the gene encoding a heat-resistant obscure (Hero) protein with chaperone activity, is a novel link in ischemic stroke

Background: Ischemic stroke (IS) is one of the most serious cardiovascular events associated with high risk of death or disability. The growing body of evidence highlights molecular chaperones as especially important players in the pathogenesis of the disease. Since six small proteins called “Hero” have been recently identified as a novel class of chaperones we aimed to evaluate whether SNP rs4644832 in SERF2 gene encoding the member of Hero-proteins, is associated with the risk of IS. Methods: A total of 1929 unrelated Russians (861 patients with IS and 1068 healthy individuals) from Central Russia were recruited into the study. Genotyping was done using a probe-based PCR approach. Statistical analysis was carried out in the whole group and stratified by age, gender and smoking status. Results: Analysis of the link between rs4644832 SERF2 and IS showed that G allele is the risk factor of IS only in females (OR=1.29, 95%CI 1.02–1.64, Padj=0.035). In addition, the analysis of associations of rs4644832 SERF2 and IS depending on the smoking status revealed that this genetic variant is associated with an increased risk of IS exclusively in non-smoking individuals (OR=1.26, 95%CI 1.01–1.56, P = 0.041). Discussion: Sex- and smoking interactions between rs4644832 polymorphism and IS may be related to the impact of tobacco components metabolism and sex hormones on SERF2 expression. Conclusion: The present study reveals the novel genetic association between rs4644832 polymorphism and the risk of IS suggesting that SERF2, the part of the protein quality control system, contributes to the pathogenesis of the disease