Structural basis of chronic beryllium disease: linking allergic hypersensitivity and autoimmunity.

T-cell-mediated hypersensitivity to metal cations is common in humans. How the T cell antigen receptor (TCR) recognizes these cations bound to a major histocompatibility complex (MHC) protein and self-peptide is unknown. Individuals carrying the MHCII allele, HLA-DP2, are at risk for chronic beryllium disease (CBD), a debilitating inflammatory lung condition caused by the reaction of CD4 T cells to inhaled beryllium. Here, we show that the T cell ligand is created when a Be(2+) cation becomes buried in an HLA-DP2/peptide complex, where it is coordinated by both MHC and peptide acidic amino acids. Surprisingly, the TCR does not interact with the Be(2+) itself, but rather with surface changes induced by the firmly bound Be(2+) and an accompanying Na(+) cation. Thus, CBD, by creating a new antigen by indirectly modifying the structure of preexisting self MHC-peptide complex, lies on the border between allergic hypersensitivity and autoimmunity.

Rhodococcus: sequences of genetic parts, analysis of their functionality, and development prospects as a molecular biology platform.

Rhodococcus bacteria are a fast-growing platform for biocatalysis, biodegradation, and biosynthesis, but not a platform for molecular biology. That is, Rhodococcus are not convenient for genetic engineering. One major issue for the engineering of Rhodococcus is the absence of a publicly available, curated, and commented collection of sequences of genetic parts that are functional in biotechnologically relevant species of Rhodococcus (R. erythropolis, R. rhodochrous, R. ruber, and R. jostii). Here, we present a collection of genetic parts for Rhodococcus (vector replicons, promoter regions, regulators, markers, and reporters) supported by a thorough analysis of their functionality. We also highlight and discuss the gaps in Rhodococcus-related genetic parts and techniques, which should be filled in order to make these bacteria a full-fledged molecular biology platform independent of Escherichia coli. We conclude that all major types of required genetic parts for Rhodococcus are available now, except multicopy replicons. As for model Rhodococcus strains, there is a particular shortage of strains with high electrocompetence levels and strains designed for solving specific genetic engineering tasks. We suggest that these obstacles are surmountable in the near future due to an intensification of research work in the field of genetic techniques for non-conventional bacteria.

Thermally activated serpentine materials as soil additives for copper and nickel immobilization in highly polluted peat.

Heat-treated serpentine products from mining wastes have been examined to remediate highly contaminated soil with total concentration of Cu 10470 mg/kg and Ni 5300 mg/kg. The series of laboratory and field experiments (for 10 years) were conducted. The modified Tessier method was used to assess the metals geochemical mobility. The effect of hydration on the chemical stability of the components and sorption properties of thermally activated serpentine were studied. The hydration of heat-treated serpentine decreased the leaching of the main components (Mg and Si) that indicates their partial binding in a newly formed compound-magnesium silicate. Hydration of heat-treated serpentine did not lead to the changes in the phase composition and the geochemical mobility of the precipitated Ni and Cu compounds. The hydration affected the sorption value at the 1 day of the interaction but after 30 days this difference partially leveled. A laboratory experiment showed that thermally activated serpentine was effective for the Cu and Ni sorption from sulfate solutions. The substantial changes in chemical properties of soil mixtures after ten years of the field experiment were found. In the first year of the field experiment, the pH values of soil mixtures were alkaline (9.4-9.9) and were significantly higher compared to the pH 4.0 of the initial peat soil. Over 10 years, the soil pH at the experimental sites gradually decreased and reached values of 7.2-8.6. The introduction of thermoactivated serpentines led to a decrease in the share of the most mobile exchangeable fraction. The most noticeable effect of thermoactivated serpentines on metal mobility in the polluted peat soil revealed for Cu; its migration coefficient decreased from 1.8 in the peat soil to 0.7 in the mixtures with heat-treated serpentines. The sum of Cu mobile fractions in the experimental variants became lower compared with initial peat by 50-70%, while Fe was lower by 30%, and Zn-by 80%. The increase in the proportion of the most strongly bound fraction was observed for all metals in the experimental variants compared with initial soil. The coefficient of metal accumulation for Ni and Cu was significantly lower than 1, indicating protective mechanisms in plants. The high content of mobile Mg and Ca compounds seems to be the determining factor in this process. The grass communities forming in the 10-years experiment showed high productivity and stability even under constant airborne industrial pollution. The thermally activated serpentine minerals can be recommended for the in situ remediation of landscapes with completely lost vegetation during the long-term impact of industrial emissions.

Interplay of Environmental, Individual and Genetic Factors in Rheumatoid Arthritis Provocation.

In this review, we explore systemization of knowledge about the triggering effects of non-genetic factors in pathogenic mechanisms that contribute to the development of rheumatoid arthritis (RA). Possible mechanisms involving environmental and individual factors in RA pathogenesis were analyzed, namely, infections, mental stress, sleep deprivation ecology, age, perinatal and gender factors, eating habits, obesity and smoking. The non-genetic factors modulate basic processes in the body with the impact of these factors being non-specific, but these common challenges may be decisive for advancement of the disease in the predisposed body at risk for RA. The provocation of this particular disease is associated with the presence of congenital loci minoris resistentia. The more frequent non-genetic factors form tangles of interdependent relationships and, thereby, several interdependent external factors hit one vulnerable basic process at once, either provoking or reinforcing each other. Understanding the specific mechanisms by which environmental and individual factors impact an individual under RA risk in the preclinical stages can contribute to early disease diagnosis and, if the factor is modifiable, might be useful for the prevention or delay of its development.

C-terminal modification of the insulin B:11-23 peptide creates superagonists in mouse and human type 1 diabetes.

A polymorphism at ß57 in some major histocompatibility complex class II (MHCII) alleles of rodents and humans is associated with a high risk for developing type 1 diabetes (T1D). However, a highly diabetogenic insulin B chain epitope within the B:9-23 peptide is presented poorly by these alleles to a variety of mouse and human CD4 T cells isolated from either nonobese diabetic (NOD) mice or humans with T1D. We have shown for both species that mutations at the C-terminal end of this epitope dramatically improve presentation to these T cells. Here we present the crystal structures of these mutated peptides bound to mouse IAg7 and human HLA-DQ8 that show how the mutations function to improve T-cell activation. In both peptide binding grooves, the mutation of B:22R to E in the peptide changes a highly unfavorable side chain for the p9 pocket to an optimal one that is dependent on the ß57 polymorphism, accounting for why these peptides bind much better to these MHCIIs. Furthermore, a second mutation of the adjacent B:21 (E to G) removes a side chain from the surface of the complex that is highly unfavorable for a subset of NOD mouse CD4 cells, thereby greatly enhancing their response to the complex. These results point out the similarities between the mouse and human responses to this B chain epitope in T1D and suggest there may be common posttranslational modifications at the C terminus of the peptide in vivo to create the pathogenic epitopes in both species.

Durvalumab alone and durvalumab plus tremelimumab versus chemotherapy in previously untreated patients with unresectable, locally advanced or metastatic urothelial carcinoma (DANUBE): a randomised, open-label, multicentre, phase 3 trial.

BACKGROUND: Survival outcomes are poor for patients with metastatic urothelial carcinoma who receive standard, first-line, platinum-based chemotherapy. We assessed the overall survival of patients who received durvalumab (a PD-L1 inhibitor), with or without tremelimumab (a CTLA-4 inhibitor), as a first-line treatment for metastatic urothelial carcinoma. METHODS: DANUBE is an open-label, randomised, controlled, phase 3 trial in patients with untreated, unresectable, locally advanced or metastatic urothelial carcinoma, conducted at 224 academic research centres, hospitals, and oncology clinics in 23 countries. Eligible patients were aged 18 years or older with an Eastern Cooperative Oncology Group performance status of 0 or 1. We randomly assigned patients (1:1:1) to receive durvalumab monotherapy (1500 mg) administered intravenously every 4 weeks; durvalumab (1500 mg) plus tremelimumab (75 mg) administered intravenously every 4 weeks for up to four doses, followed by durvalumab maintenance (1500 mg) every 4 weeks; or standard-of-care chemotherapy (gemcitabine plus cisplatin or gemcitabine plus carboplatin, depending on cisplatin eligibility) administered intravenously for up to six cycles. Randomisation was done through an interactive voice-web response system, with stratification by cisplatin eligibility, PD-L1 status, and presence or absence of liver metastases, lung metastases, or both. The coprimary endpoints were overall survival compared between the durvalumab monotherapy versus chemotherapy groups in the population of patients with high PD-L1 expression (the high PD-L1 population) and between the durvalumab plus tremelimumab versus chemotherapy groups in the intention-to-treat population (all randomly assigned patients). The study has completed enrolment and the final analysis of overall survival is reported. The trial is registered with ClinicalTrials.gov, NCT02516241, and the EU Clinical Trials Register, EudraCT number 2015-001633-24. FINDINGS: Between Nov 24, 2015, and March 21, 2017, we randomly assigned 1032 patients to receive durvalumab (n=346), durvalumab plus tremelimumab (n=342), or chemotherapy (n=344). At data cutoff (Jan 27, 2020), median follow-up for survival was 41·2 months (IQR 37·9-43·2) for all patients. In the high PD-L1 population, median overall survival was 14·4 months (95% CI 10·4-17·3) in the durvalumab monotherapy group (n=209) versus 12·1 months (10·4-15·0) in the chemotherapy group (n=207; hazard ratio 0·89, 95% CI 0·71-1·11; p=0·30). In the intention-to-treat population, median overall survival was 15·1 months (13·1-18·0) in the durvalumab plus tremelimumab group versus 12·1 months (10·9-14·0) in the chemotherapy group (0·85, 95% CI 0·72-1·02; p=0·075). In the safety population, grade 3 or 4 treatment-related adverse events occurred in 47 (14%) of 345 patients in the durvalumab group, 93 (27%) of 340 patients in the durvalumab plus tremelimumab group, and in 188 (60%) of 313 patients in the chemotherapy group. The most common grade 3 or 4 treatment-related adverse event was increased lipase in the durvalumab group (seven [2%] of 345 patients) and in the durvalumab plus tremelimumab group (16 [5%] of 340 patients), and neutropenia in the chemotherapy group (66 [21%] of 313 patients). Serious treatment-related adverse events occurred in 30 (9%) of 345 patients in the durvalumab group, 78 (23%) of 340 patients in the durvalumab plus tremelimumab group, and 50 (16%) of 313 patients in the chemotherapy group. Deaths due to study drug toxicity were reported in two (1%) patients in the durvalumab group (acute hepatic failure and hepatitis), two (1%) patients in the durvalumab plus tremelimumab group (septic shock and pneumonitis), and one (<1%) patient in the chemotherapy group (acute kidney injury). INTERPRETATION: This study did not meet either of its coprimary endpoints. Further research to identify the patients with previously untreated metastatic urothelial carcinoma who benefit from treatment with immune checkpoint inhibitors, either alone or in combination regimens, is warranted. FUNDING: AstraZeneca.

Development and implementation of guidelines for the management of depression: a systematic review.

OBJECTIVE: To evaluate the development and implementation of clinical practice guidelines for the management of depression globally. METHODS: We conducted a systematic review of existing guidelines for the management of depression in adults with major depressive or bipolar disorder. For each identified guideline, we assessed compliance with measures of guideline development quality (such as transparency in guideline development processes and funding, multidisciplinary author group composition, systematic review of comparative efficacy research) and implementation (such as quality indicators). We compared guidelines from low- and middle-income countries with those from high-income countries. FINDINGS: We identified 82 national and 13 international clinical practice guidelines from 83 countries in 27 languages. Guideline development processes and funding sources were explicitly specified in a smaller proportion of guidelines from low- and middle-income countries (8/29; 28%) relative to high-income countries (35/58; 60%). Fewer guidelines (2/29; 7%) from low- and middle-income countries, relative to high-income countries (22/58; 38%), were authored by a multidisciplinary development group. A systematic review of comparative effectiveness was conducted in 31% (9/29) of low- and middle-income country guidelines versus 71% (41/58) of high-income country guidelines. Only 10% (3/29) of low- and middle-income country and 19% (11/58) of high-income country guidelines described plans to assess quality indicators or recommendation adherence. CONCLUSION: Globally, guideline implementation is inadequately planned, reported and measured. Narrowing disparities in the development and implementation of guidelines in low- and middle-income countries is a priority. Future guidelines should present strategies to implement recommendations and measure feasibility, cost-effectiveness and impact on health outcomes.

In Situ and ex Situ Study of Cubic La0.5Ba0.5CoO3-δ to Double Perovskite LaBaCo2O6-δ Transition and Formation of Domain Textured Phases with Fast Oxygen Exchange Capability.

The disordered La0.5Ba0.5CoO3-δ ↔ ordered LaBaCo2O6-δ transition was studied in detail using several complementary in situ (X-ray diffraction, thermogravimetry, and coulometric titration) and ex situ (transmission electron microscopy) techniques. This transition was found to proceed through the formation of complex domain textured intermediate products. They were shown to have strong affinity to oxygen and exhibit its fast absorption from ambient atmosphere (oxygen partial pressure ( pO2) 0.21 atm) at a temperature as low as 70 °C. The thermodynamic stability limits of the cubic and double perovskites were determined by coulometric titration. The stability diagram of the LaBaCo2O6-δ - La0.5Ba0.5CoO3-δ system was plotted as a result. Oxygen nonstoichiometry of the thermodynamically stable cubic perovskite La0.5Ba0.5CoO3-δ was measured as a function of pO2 in the temperature range between 1000 and 1100 °C using a coulometric titration technique.

Using DR52c/Ni2+ mimotope tetramers to detect Ni2+ reactive CD4+ T cells in patients with joint replacement failure.

T cell mediated hypersensitivity to nickel (Ni2+) is one of the most common causes of allergic contact dermatitis. Ni2+ sensitization may also contribute to the failure of Ni2+ containing joint implants, and revision to non-Ni2+ containing hardware can be costly and debilitating. Previously, we identified Ni2+ mimotope peptides, which are reactive to a CD4+ T cell clone, ANi2.3 (Vα1, Vß17), isolated from a Ni2+ hypersensitive patient with contact dermatitis. This T cell is restricted to the major histocompatibility complex class II (MHCII) molecule, Human Leukocyte Antigen (HLA)-DR52c (DRA, DRB3*0301). However, it is not known if Ni2+ induced T cell responses in sensitized joint replacement failure patients are similar to subjects with Ni2+ induced contact dermatitis. Here, we generated DR52c/Ni2+ mimotope tetramers, and used them to test if the same Ni2+ T cell activation mechanism could be generalized to Ni2+ sensitized patients with associated joint implant failure. We confirmed the specificity of these tetramers by staining of ANi2.3T cell transfectomas. The DR52c/Ni2+ mimotope tetramer detected Ni2+ reactive CD4+ T cells in the peripheral blood mononuclear cells (PBMC) of patients identified as Ni2+ sensitized by patch testing and a positive Ni2+ LPT. When HLA-typed by a DR52 specific antibody, three out of four patients were DR52 positive. In one patient, Ni2+ stimulation induced the expansion of Vß17 positive CD4+ T cells from 0.8% to 13.3%. We found that the percentage of DR52 positivity and Vß17 usage in Ni2+ sensitized joint failure patients are similar to Ni sensitized skin allergy patients. Ni2+ independent mimotope tetramers may be a useful tool to identify the Ni2+ reactive CD4+ T cells.

Tepidibacillus infernus sp. nov., a moderately thermophilic, selenate- and arsenate-respiring hydrolytic bacterium isolated from a gold mine, and emended description of the genus Tepidibacillus.

A novel aerotolerant anaerobic, moderately thermophilic, organotrophic bacterium, strain MBL-TLPT, was isolated from a sample of microbial mat, developed under the flow of subsurface water in TauTona gold mine, South Africa. Cells of the new isolate were flagellated, spore-forming rods, 0.25-0.5 µm in width and 3-15 µm in length. Strain MBL-TLPT grew in the temperature range from 25 to 58 °C, pH range from 5.6 to 8.8 and at NaCl concentration from 0 to 85 g l-1. The isolate was able to ferment yeast extract and mono-, oligo- and polysaccharides, including starch and xanthan gum. The G+C content of the DNA was 35 mol%. Phylogenetic analysis of 16S rRNA gene sequences of strain MBL-TLPT and relatives showed its affiliation to the genus Tepidibacillus. Tepidibacillus fermentans STGHT was its closest relative (97.1 % identity of 16S rRNA gene sequences). Based on phylogenetic analysis and the physiological properties of the novel isolate, we propose a novel species, Tepidibacillus infernus sp. nov., with MBL-TLPT(=DSM 28123T=VKM В-2949T) as the type strain.

Sensitivity of microbial bioindicators in assessing metal immobilization success in smelter-impacted soils.

While plant toxicity reduction remains the primary metric for judging the success of metal immobilization in soil, the suitability of microorganisms as universal indicators of its effectiveness in various contaminated soils remains a point of contention. This study assessed the sensitivity of microbial bioindicators in monitoring metal immobilization success in smelter-impacted soils. It compared plants and microorganisms as indicators of the efficiency of natural Fe-Mn nodules from the Gulf of Finland in immobilizing metals in soils contaminated by a Ni/Cu smelter, on the Kola Peninsula, Murmansk region, Russia. Perennial ryegrass (Lolium perenne) was grown on nodule-amended and control soils. Plant responses in the smelter-impacted soils proved to be sensitive and robust indicators of successful metal immobilization. However, microbial responses exhibited a more complex story. Despite the observed reductions in soluble metal concentrations, shoot metal contents in ryegrass, and significant improvements in plant growth, certain microbial bioindicators were unresponsive to metal immobilization success brought about by the addition of Fe-Mn nodules. Among microbial bioindicators studied, community-level physiological profiling, microbial biomass carbon, and basal respiration were sensitive indicators of metal immobilization success, whereas the number of saprotrophic, oligotrophic, and Fe-oxidizing bacteria and fungi, the biomass of bacteria and fungi, and enzymatic activity were less robust indicators. Interestingly, the correlations between different microbial responses measured were weak or even negative. Some microbial responses also exhibited negative correlations with plant biomass. These findings underscore the need for further research on comparative evaluations of plants and microorganisms as reliable indicators of metal immobilization efficacy in polluted environments.

A new concept of biocatalytic synthesis of acrylic monomers for obtaining water-soluble acrylic heteropolymers.

Rhodococcus strains were designed as model biocatalysts (BCs) for the production of acrylic acid and mixtures of acrylic monomers consisting of acrylamide, acrylic acid, and N-alkylacrylamide (N-isopropylacrylamide). To obtain BC strains, we used, among other approaches, adaptive laboratory evolution (ALE), based on the use of the metabolic pathway of amide utilization. Whole genome sequencing of the strains obtained after ALE, as well as subsequent targeted gene disruption, identified candidate genes for three new amidases that are promising for the development of BCs for the production of acrylic acid from acrylamide. New BCs had two types of amidase activities, acrylamide-hydrolyzing and acrylamide-transferring, and by varying the ratio of these activities in BCs, it is possible to influence the ratio of monomers in the resulting mixtures. Based on these strains, a prototype of a new technological concept for the biocatalytic synthesis of acrylic monomers was developed for the production of water-soluble acrylic heteropolymers containing valuable N-alkylacrylamide units. In addition to the possibility of obtaining mixtures of different compositions, the advantages of the concept are a single starting reagent (acrylamide), more unification of processes (all processes are based on the same type of biocatalyst), and potentially greater safety for personnel and the environment compared to existing chemical technologies.

Halonatronomonas betaini gen. nov., sp. nov., a haloalkaliphilic isolate from soda lake capable of betaine degradation and proposal of Halarsenatibacteraceae fam. nov. and Halothermotrichaceae fam. nov. within the order Halanaerobiales.

A search for the organisms responsible for anaerobic betaine degradation in soda lakes resulted in isolation of a novel bacterial strain, designated Z-7014T. The cells were Gram-stain-negative, non-endospore-forming rods. Growth occurred at 8-52 °C (optimum 40-45 °C), pH 7.1-10.1 (optimum pH 8.1-8.8) and 1.0-3.5 M Na+ (optimum 1.8 M), i.e. it can be regarded as a haloalkaliphile. The strain utilized a limited range of substrates, mostly peptonaceous but not amino acids, and was able to degrade betaine. Growth on betaine occurred only in the presence of peptonaceous substances which could not be replaced by vitamins. The G + C content of the genomic DNA of strain Z-7014T was 36.1 mol%. The major cellular fatty acids (>5% of the total) were C16:0 DMA, C18: 0 DMA, C16:1ω8, C16:0, C18:1 DMA, C16:1 DMA, C18:1ω9, and C18:0. Phylogenetic analysis of the 16S rRNA gene sequence revealed that strain Z-7014T formed a distinct evolutionary lineage in the order Halanaerobiales with the highest similarity to Halarsenitibacter silvermanii SLAS-1T (83.6%), Halothermothrix orenii H168T (85.6%), and Halocella cellulosilytica DSM 7362T (85.6%). AAI and POCP values between strain Z-7014T and type strains of the order Halanaerobiales were 51.7-57.8%, and 33.8-58.3%, respectively. Based on polyphasic results including phylogenomic data, the novel strain could be distinguished from other genera, which suggests that strain Z-7014T represents a novel species of a new genus, for which the name Halonatronomonas betaini gen. nov., sp. nov. is proposed. The type strain is Z-7014T (=KCTC 25237T = VKM B-3506T). On the basis of phylogenomic data, it is also proposed to evolve two novel families Halarsenitibacteraceae fam. nov. and Halothermotrichaceae fam. nov. within the current order Halanaerobiales.

Diversity of Microbial Communities, PAHs, and Metals in Road and Leaf Dust of Functional Zones of Moscow and Murmansk.

The impact of geographical factors, functional zoning, and biotope type on the diversity of microbial communities and chemical components in the dust of urban ecosystems was studied. Comprehensive analyses of bacterial and fungal communities, polycyclic aromatic hydrocarbons (PAHs), and metals in road and leaf dust in three urban zones of Murmansk and Moscow with contrasting anthropogenic load were conducted. We found that the structure of bacterial communities affected the functional zoning of the city, biotope type, and geographical components. Fungal communities were instead impacted only by biotope type. Our findings revealed that the structure of fungal communities was mostly impacted by PAHs whereas bacterial communities were sensitive to metals. Bacteria of the genus Sphingomonas in road and leaf dust as indicators of the ecological state of the urban ecosystems were proposed.

Serpentine Overburden Products-Nature-Inspired Materials for Metal Detoxification in Industrially Polluted Soil.

The possibility of plants growing on serpentine soils and the ability of serpentine minerals to accumulate significant amounts of metals was the basis for developing a method for using serpentine-containing materials to restore vegetation in areas with a high level of metal pollution. Serpentine-containing products obtained from phlogopite mining overburden (Kovdor, Murmansk region, Russia) with and without thermal activation were used in a field experiment on the remediation of industrially polluted peat soil. According to the geochemical mobility of the components, one of four fractions was allocated depending on the acidic (HCl) concentration of the solution used for the material treatment: readily mobile (0.001 mol/L), mobile (0.01 mol/L), potentially mobile (0.1 mol/L), and acid-soluble (1.0 mol/L). This study showed that the addition of serpentinites to peat soil changed the fraction composition. The most significant changes were noted for serpentinite components such as Ca and Mg: their concentrations increased 2-3 times even in the smallest portion of serpentine material. On the contrary, the contents of metals in the readily mobile fraction decreased 3-18, 3-23, 5-26, and 2-42 times for Cu, Ni, Fe, and Al, respectively. The main factor causing the decrease in metal mobility was the pH rise due to the release of Ca and Mg compounds into the soil solution. This study showed that the addition of serpentine-containing material at 25 vol.% to peat soil was sufficient to create a geochemical barrier with a stable-functioning vegetation cover. All serpentine-containing materials are recommended for the remediation of large industrially polluted areas.

Rhodovulum tesquicola sp. nov., a haloalkaliphilic purple non-sulfur bacterium from brackish steppe soda lakes.

Two strains of purple non-sulfur bacteria (A-36s(T) and A-51s) were isolated from brackish steppe soda lakes of southern Siberia. Genetically, the isolates were related most closely to the type strains of Rhodovulum steppense and Rhodovulum strictum, from which they differed at the species level (98.5% 16S rRNA gene sequence similarity, 40-53% DNA-DNA relatedness). Cells of the two strains were ovoid to rod-shaped, 0.4-0.8 µm wide and 1.0-2.5 µm long, and motile by means of a polar flagellum. They contained internal photosynthetic membranes of vesicular type and photosynthetic pigments (bacteriochlorophyll a and carotenoids of the spheroidene series). The strains were obligate haloalkaliphiles, growing over wide ranges of salinity (0.3-10.0% NaCl) and pH (7.5-10.0), with growth optima at 1.0-3.0% NaCl and pH 8.5-9.0. Photoheterotrophic and chemoheterotrophic growth occurred with a number of organic compounds and biotin, p-aminobenzoate, thiamine and niacin as growth factors. No anaerobic respiration on nitrite, nitrate or fumarate and no fermentation were demonstrated. The strains grew photolithoautotrophically and chemolithoautotrophically with sulfide, sulfur and thiosulfate, oxidizing them to sulfate. Sulfide was oxidized via deposition of extracellular elemental sulfur. No growth with H(2) as the electron donor was observed. The major fatty acid was C(18:1) (78%). The major quinone was ubiquinone Q-10. The DNA G+C content of strain A-36s(T) was 65.4 mol% (T(m)). According to genotypic and phenotypic characteristics, the investigated strains were assigned to a novel species of the genus Rhodovulum, for which the name Rhodovulum tesquicola sp. nov. is proposed. The type strain is A-36s(T) ( = VKM B-2491(T) = ATCC BAA-1573(T)), which was isolated from steppe soda lake Sul'fatnoe (Zabaikal'skii Krai, southern Siberia, Russia).

Polycyclic Aromatic Hydrocarbon-Degrading Bacteria in Three Different Functional Zones of the Cities of Moscow and Murmansk.

We performed a comparative study of the total bacterial communities and communities of cultivable polycyclic aromatic hydrocarbons (PAH)-degrading bacteria in different functional zones of Moscow and Murmansk that were formed under the influence of the PAH composition in road and leaf dust. The PAHs were determined by high-performance liquid chromatography (HPLC); the bacterial communities' diversity was assessed by metabarcoding. The degraders were isolated by their direct plating on a medium with the PAHs. The PAH total quantity declined in the leaf dust from the traffic to the recreational zone. For the road dust, a negative gradient with pollution was observed for Rhodococcus and Acinetobacter degraders and for their relative abundance in the microbiome for the functional zones of Moscow. The opposite effect was observed in the Murmansk leaf dust for the Rothia and Pseudomonas degraders and in the Moscow road dust for Microbacterium. The PCA and linear regression analyses showed that the Micrococcus degraders in the dust were sensitive to anthropogenic pollution, so they can be used as a tool for monitoring anthropogenic changes in the biosphere. The data on the degraders' and microbial communities' diversity suggest that minor degrading strains can play a key role in PAH degradation.

Carboxydothermus islandicus sp. nov., a thermophilic, hydrogenogenic, carboxydotrophic bacterium isolated from a hot spring.

An anaerobic, thermophilic bacterium, strain SET IS-9(T), was isolated from an Icelandic hot spring. Cells of strain SET IS-9(T) are short, slightly curved, motile rods. The strain grows chemolithotrophically on CO, producing equimolar quantities of H(2) and CO(2). It also grows fermentatively on lactate or pyruvate in the presence of yeast extract (0.2 g l(-1)). Products of pyruvate fermentation are acetate, CO(2) and H(2). Growth occurs at 50-70 °C, with an optimum at 65 °C, and at pH 5.0-8.0, with an optimum at pH 5.5-6.0. The generation time during chemolithotrophic growth on CO under optimal conditions is 2.0 h. 16S rRNA gene sequence analysis suggested that the organism belongs to the genus Carboxydothermus. On the basis of phenotypic features and phylogenetic analysis, Carboxydothermus islandicus sp. nov. is proposed, with the type strain SET IS-9(T) ( = DSM 21830(T)  = VKM B-2561(T)). An emended description of the genus Carboxydothermus is also given.

In Situ Control of Thermal Activation Conditions by Color for Serpentines with a High Iron Content.

Serpentine heat treatment at temperatures of 650-750 °C yields magnesium-silicate reagent with high chemical activity. Precise and express control of roasting conditions in laboratory kilns and industrial aggregates is needed to derive thermally activated serpentines on a large scale. Color change in serpentines with a high iron content during roasting might be used to indicate the changes in chemical activity in the technological process. This study gives a scientific basis for the express control of roasting of such serpentines by comparing the colors of the obtained material and the reference sample. Serpentines with different chemical activity were studied by X-ray diffraction, Mössbauer spectroscopy, and optical spectroscopy. The color parameters were determined using RGB (red, green, blue), CIELAB (International Commission on Illumination 1976 L*a*b), and HSB (hue, brightness, saturation) color models. The color of heat-treated samples was found to be affected by changes in the crystallochemical characteristics of iron included in the structure of the serpentine minerals. The color characteristics given by the CIELAB model were in good coherence with the acid-neutralizing ability and optical spectra of heat-treated serpentines. Thus, in contrast to the long-term analysis by these methods, the control by color palette provides an express assessment of the quality of the resulting product.