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In 2002, Wolf described a new species of Stenotrophomonas, Stenotrophomonas rhizophila, which is a non-pathogenic plant inhabitant. The defining characteristics of the new species, in contrast to S. maltophilia, were the following: growth at 4 °C, but its absence at 37 °C; the use of xylose as a carbon source; low osmolytic tolerance. S. rhizophila is isolated exclusively from the rhizosphere or from the internal tissues of plants, in particular from the vascular tissues of the root and stem. In 2014, a number of authors, studying cultivated heterotrophic bacteria and yeasts, which dominate in plant samples collected from various terrestrial biotopes near the Ukrainian Antarctic station on Galindez Island in Marine Antarctica, isolated a number of bacterial isolates. The authors' phylogenetic analysis using only BLAST analysis made it possible to determine the approximate phylogenetic affiliation of the bacterial isolate to the family Gammaproteobacteria (genus Stenotrophomonas, species S. rhizophila). It is known that many processes that determine the biological features of microorganisms, the nature of their relationships between them, as well as micro- and macroorganisms in biocenoses, are carried out with the participation of the surface structures of the bacterial cell, which are in direct contact with the environment. Among them, of particular interest are lipopolysaccharides (LPS), components of the outer membrane of Gram-negative bacteria. However, to date, we have not found any works devoted to the study of S. rhizophila lipopolysaccharides in the literature available to us. The aim of the work was to clarify the phylogenetic position of the 6p5m bacterial strain isolated from the Antarctic region by constructing dendrograms, to study some of its phenotypic properties, to isolate lipopolysaccharides and study chemical and component composition, serological, and biological properties. Methods. Identification was carried out via ribosomal phylogeny. A fragment of the 16S rRNA gene of bacterial strain 6p5m was amplified by PCR using primers 8F and 1492R. The phylogenetic position of the strains was determined by construction of dendrograms, which show the position of the investigated strains among closely related and typical species and type species (programs ClustalX 2.1, Mega v. 6.00). LPS was obtained from cells by water-phenol extraction, electrophoresis was carried out in polyacrylamide gel, monosaccharide and fatty acid composition was determined by chromato-mass spectrometry, antigenic activity was studied by immunodiffusion in agar. Results. Phylogenetic analysis of the nucleotide sequence of the 16S rRNA gene revealed a high level of homology (99.8%) of the bacterial strain 6p5m with typical strain S. rhizophila DSM 14405T from the GenBank database, which allows us to classify it. Comparing phylogenetic analysis with phenotypic data, we can assert that strain 6p5m belongs to the S. rhizophila species. When studying the biopolymer composition of LPS by specific reactions to each component, it was found that the carbohydrate content was relatively low and amounted to 27.42% and 13.34% for LPS1 and LPS2, respectively. The content of characteristic LPS components: heptose and 2-keto-3-deoxyoctonic (KDO) acid was 1.78% and 0.034%, as well as 5.38% and 0.09%, respectively, for LPS1 and LPS2. Analysis of the monosaccharide composition of LPS preparations showed that fucose (72.57%) is present as a dominant monosaccharide in LPS1 and rhamnose (65.04%) in LPS2. The main monosaccharides of the extracellular component were galactose (39.92%) and rhamnose (24.36%). Analysis of the lipid part of the studied LPS indicates significant differences between them. In the composition of lipid A LPS1 and LPS2 of S. rhizophila 6p5m, anti-iso-pentadecanoic acid (a-i-C15:0) was predominant (25.58% and 39.24%, respectively), and 3-hydroxydodecanoic acid (3-OH-C12:0) in LPS2 (26.21%), hexadecanoic acid (С16:0) (27.06% and 10.51%, respectively) for LPS1 and LPS2. Cyclic acids were present only in LPS1, while i-C15:0 and 9-C16:1 only in LPS2. Electrophoretic analysis showed heterogeneity characteristic of an LPS molecule, manifested by a plurality of bands in the form of a «ladder» when the gel was stained with silver ions, which is associated with the presence in the composition of LPS preparations of Ospecific polysaccharide structures with different lengths of oligosaccharide chains, which determine their different molecular weight. On the electropherogram of LPS1 and LPS2, bands were not visualized in the upper part of the electrophoretic track, which indicates the absence of S-forms of LPS with long O-specific chains, but a significant predominance of SR-form molecules in the membrane LPS pool. S. rhizophila 6p5m LPS showed significantly higher pyrogenic activity compared to pyrogenal, a pharmaceutical preparation, an active ingredient of which is Shigella typhi LPS. The extracellular polymer did not exhibit pyrogenic activity. In the double immunodiffusion reaction in agar according to Ouchterlony, it was found that the studied LPSs in the homologous system exhibit antigen activity. The antigens present in both LPS1and LPS2 and the extracellular component are identical: the antigen present in each of the wells binds to all antibodies that can interact with the antigen from the other well. It was shown that pre-sowing treatment of seeds with LPS preparations of S. rhizophila 6p5m stimulates the energy of seed germination. LPS1 (+2.82 cm) showed the greatest impact in comparison with the control. A significant stimulatory effect of LPS1, LPS2, and extracellular polymer was observed when studying their effects on mustard seedlings. Conclusions. The taxonomic position of bacterial strain 6r5m of the ecosystems of the polar region (Antarctica) was determined via the phylogenetic analysis taking into account the phenotypic features of the strain. The bacterial strain is represented in the phylum Proteobacteria, class Gammaproteobacteria, family Xanthomonadaceae, genus Stenotrophomonas, species S. rhizophila. From S. rhizophila cells, LPS preparations were obtained, which differed in monosaccharide and fatty acid composition, but showed high pyrogenicity. S. rhizophila represents a promising alternative to S. maltophilia for applications in agricultural biotechnology and biological control due to its ability to both stimulate plant growth and protect roots from biotic and abiotic stresses. [ABSTRACT FROM AUTHOR]

The aim of the work was quantitative determination of Fe(III)-reducing bacteria in natural ecosystems of the Antarctic, the Arctic, the Dead and the Black Sea, middle latitude (Ukraine, Abkhazia) and the equatorial zone (Ecuador). It was used the method of quantitative determination of microorganisms by McCready and the colorimetric method for determination of Fe(II) compounds . Results. The systemic study of the number of Fe(III)-reducing bacteria of both hemispheres in the ecosystems of six geographic regions was carried out for the first time. High number of Fe(III)-reducing bacteria in natural ecosystems was experimentally shown. The number of Fe(III)-reducing bacteria ranged from 1.1•102 to 2.8•107 cells/g of absolutely dry sample. Conclusions. The presented data showed that Fe(III)-reducing bacteria are an integral part of natural ecosystems and can significantly affect the biogeochemical cycles of iron and carbon compounds transformation.

To determine the studied bacteria resistance quantitative parameters of extreme factors such as toxic metals (Cu2+), organic xenobiotics (p-nitrochlorobenzene) and UV-irradiation were the aim of the research. Six strains of nitrogen-fixing bacteria isolated from clays of two caverns Mushkarova Yama (Podolia, Ukraine) and Kuybyshevskaya (Western Caucasus, Abkhazia) and Azotobacter vinelandii УКМ В-6017 as a reference strain have been tested. For this purpose the maximum permissible concentration of Cu2+ and p-nitrochlorobenzene in the concentration gradient and lethal doses of UV by the survival caverns have been determined. Maximum permissible concentrations for strains were as 10 ppm Cu2+, 70–120 ppm of p-nitrochlorobenzene. The maximum doses of UV-irradiation varied in the range of 55–85 J/m2 (LD99.99). It is shown that three classes of extreme factors resistance parameters of karst caverns strains are similar to the strain of terrestrial soil ecosystems. The most active studied strains reduce the concentration of p-nitrochlorobenzene in the medium in 13 times. The ability of nitrogen-fixing bacteria to degrade p-nitrochlorobenzene could be used in creation new environmental biotechnology for industrial wastewater treatment from nitrochloroaromatic xenobiotics. Isolated strains could be used as destructors for soils bioremediation in agrobiotechnologies and to optimize plants nitrogen nutrition in terrestrial ecosystems.

Hydrogen production by microorganisms is studied by using different sources of carbon for their cultivation. Purple non-sulfur bacteria are capable of producing molecular hydrogen phototrophically with the simultaneous accumulation of biomass on organic substrates that may be waste from various industries. That fact makes the study of this group of microorganisms very much promising. The aim. The determination of the ability of purple non-sulfur bacteria Rhodopseudomonas yavorovii IMV B-7620 to produce hydrogen consuming different organic substrates and their effects on the main metabolic indicators of culture growth. Methods. Bacteria were grown in 100 mL glass jars in liquid modified ATCC No. 1449 medium for 14 days at temperature +27...+30 ºC and at constant light (200 lux). Biomass accumulation and hydrogen production in the cultivation medium were determined using sodium acetate (12 and 36 mM), malate (12 and 36 mM), succinate (36 mM), glucose (36 mM), starch (36 mM), sodium citrate (36, 60, 90 mM). Biomass was determined turbidimetrically, the composition of the gas phase was determined using a gas chromatograph LHM-8-MD, redox potential and pH were estimated potentiometrically. The volume of gas synthesized was measured on a syringe scale. Determination of the content of organic acids in the culture liquid was analyzed by high performance liquid chromatography. Results. The utilization of organic compounds (malate, glucose, starch, sodium citrate) by R. yavorovii IMV B-7620 is accompanied by hydrogen synthesis. Under the growth with sodium acetate, bacteria produce small amounts of succinate. The malate metabolism results in the production of small amounts of fumarate on the 7th day of cultivation and isocitrate on the 10th day of cultivation. On the 14th day of cultivation, the cultural liquid contains a small amount of succinate. On the 14th day of cultivation, R. yavorovii IMV B-7620 produces 7.64±0.04% of hydrogen in the medium with malate (36 mM). However, the maximum concentration of hydrogen in the gas phase (21.26±0.08%) was gained on the 14th day of cultivation in the medium with sodium citrate. The maximum concentration of H2 in the gas phase during the growth in the medium with sodium citrate (60 mM) and NH4+ was 27.83±5.46% on the 7th day of cultivation and 35.69±0.40% with increasing concentration of sodium citrate up to 90 mM on the 10th day of cultivation. The total volume of hydrogen was 25.54±0.49 mL of H2 during the growth of R. yavorovii IMV B-7620 in the medium with 90 mM sodium citrate and NH4+. That is 1.5 times more than the amount of H2 produced during the growth of bacteria in the medium with 60 mM sodium citrate with the addition of NH4+. Conclusion. Purple non-sulfur bacteria R. yavorovii IMV B-7620 synthesize hydrogen during photofermentation of organic compounds. Bacteria were isolated from the water of Yavoriv Lake (Lviv region, Ukraine) formed as a result of flooding of the sulfur quarry. Bacteria consume sodium citrate, malate, glucose, starch and emit hydrogen. The total volume of hydrogen during the growth of R. yavorovii IMV B-7620 in the medium with 90 mM sodium citrate and NH4+ is 25.54±0.49 mL H2. [ABSTRACT FROM AUTHOR]

Purpose. The purpose of this research was the investigation of the possibility of using bromothymol blue as a RedOx indicator and the measuring of RedOx potential value of bromothymol blue decolouring. Methods. The research was run using conventional microbiological, potentiometrical, physical and chemical methods. Results. It is shown for the first time, that bromothymol blue is a multipurpose indicator for the determination of pH and RedOx potential (Eh) of the medium during the heterophase solid substrate fermentation by microorganisms. The bromothymol blue solution provides the visual control over the pH value dynamics in the range of 4,5 - 7,5 and Eh ≥ -200 mV (at рН 7,0). Conclusions. Application of bromothymol blue in the heterophase fermentation of solid substrate allows visualising of the zones with altered pH and Eh, their stereometric distribution and changing configuration in time. The ability of bromothymol blue to be a RedOx indicator as well as pH indicator expands the opportunity of its use in microbiological and biothechnological research. [ABSTRACT FROM AUTHOR]

The aim of the research was to develop theoretic principles of an efficient biotechnology for microbial purification of concentrated sewage filtrate from a wide range of organic and non-organic compounds, and experimentally confirm these principles. The experiment combined conventional microbiological, physical and chemical methods in which ten different types of solid carriers, both natural and artificial, were used. A comparative analysis of these types of solid carriers used in the flow system and a structured evaluation of treatment parameters was provided. The obtaining results demonstrated the effectiveness of the use of method sewage microbial purification in a flow system. Developed principles can be used as a basis for new efficient biotechnologies for sewage microbial purification. [ABSTRACT FROM AUTHOR]

Solid food waste is a significant threat to the environment. Thermodynamic calculations allow determining theoretically possible metabolic pathways for degradation of organic compounds by microorganisms, and to select the optimal one to increase efficiency of food waste recycling. The purpose of our work was application of thermodynamic calculations to find out suitable fermentation parameters for regulation of microbial metabolism to ensure a high rate of waste decomposition and formation of valuable products. The following methods were used: colorimetric and potentiometric for pH and oxidation-reduction potential (ORP) measurement, volumetric and chromatographic for the study of volume and composition of synthesised gas, and mathematical for fermentation parameters calculation. Fermentation of multicomponent kitchen food waste under theoretically calculated optimal parameters pH = 7.0 and Eh in the range form -250 to -350 mV provided extremely high metabolic activity of a hydrogen-producing microbial community, which resulted in a decrease in duration of batch fermentation to three days and an increase in hydrogen yield from 16 to 80-115 L/kg of dry waste. The coefficient of waste destruction (Kd), i.e., the ratio of initial and final weight of waste, reached 91. Obtained after fermentation, an unfermented lignocellulosic substrate was shown to be applied as plant probiotics and to supply mineral nitrogen for plant nutrition in an arid condition. Thus, high efficiency of application of a thermodynamic prognosis method of microbial interaction with organic compounds was shown to become the base for biotechnology of destruction of environmentally hazardous solid food waste with simultaneous obtainment of valuable products: environmentally friendly energy carrier - molecular hydrogen, as well as a lignocellulosic substrate to increase crop yields. [ABSTRACT FROM AUTHOR]

The paper presents the final results of a five-year research (2011-2015) conducted at the Extremophilic Microorganism Biology Department. Extremotolerant microorganisms were isolated from phytocenoses and soils of West Antarctic; subtropical soils (Israel), karst caves and soils of temperate regions (Ukraine, Bulgaria), silt of hypersaline lakes of Crimea (Ukraine) and the Dead Sea (Israel), highland areas of Andes (Ecuador). 10% of them were resistant to toxic metals, 1-chloro-4-nitrobenzene, UV radiation, high salinity, as well as to low and high temperatures. A method of thermodynamic prognosis of microbial interaction with various toxic compounds was developed, providing a theoretical background for designing new environmental biotechnologies. It enabled to determine the conditions for microbial metabolism regulation that provide for complete degradation of synthetic organic compounds and food wastes as well as for production of energy carriers (H2, CH4, ethanol, solid fuel). The specified approach resulted an isolation of a number of strains that were resistant to the most toxic metals (Hg2+, Cu2+, Ni2+, Fe3+, Fe2+, CrO42-) and performed a variety of interactions with metal compounds including mobilization and immobilization, dissolving and sedimentation. Biodiversity of microorganisms in West Antarctica was studied by means of standard microbiological methods as along with phylogenetic and metagenomic analysis. Pyrosequencing of 16S rDNA amplicons of microbial communities in the studied samples revealed representatives of 20 bacterial phyla. Microbiological methods identified cultivable representatives of four phyla (Actinobacteria, Firmicutes, Proteobacteria, Bacteroidetes), which included 25 species. The paper presents the results of taxonomic and/or biotechnology studies of specialized groups of extremophiles: ironreducing bacteria, hydrogen-producing bacteria and obligate methane-oxidizing bacteria. [ABSTRACT FROM AUTHOR]

The aim of the work was to show the possibility for the strain Citrobacter freundii Ml-31.1/1 on the base of its metabolism regulation to carry out two opposite processes: mobilization of iron compounds and their immobilization. To do this investigation thermodynamic calculations were used. It was also used potentiometric measuring of pH and Eh values, colorimetric determination of microbial biomass increase and changes of iron compounds concentration and gas chromatography. The possibility of theoretically grounded regulation of iron transformation pathways was experimentally confirmed. Taking as an example the culture C. freundii Ml-31.1/1, we have shown its ability to provide both immobilization and mobilization of iron compounds under specific conditions for microbial growth in nutrient medium. Obtained regularities are the basis to estimate the role of microorganisms in iron biogeochemical cycles. These data could be used as a base for the development of effective biotechnological approaches such as iron extraction from depleted deposits and water purification from iron compounds. [ABSTRACT FROM AUTHOR]

Four novel Pseudomonas strains with record resistance to copper (Cu 2+ ) previously isolated from ecologically diverse samples ( P. lactis UKR1, P. panacis UKR2, P. veronii UKR3, and P. veronii UKR4) were tested against sonochemically synthesised copper-oxide (I) (Cu 2 O) and copper-oxide (II) (CuO) nanoparticles (NPs). Nanomaterials characterisation by X-ray diffractometry (XRD), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FTIR), and High-Resolution Transmission Electron Microscopy (HRTEM) confirmed the synthesis of CuO and Cu 2 O NPs. CuO NPs exhibited better performance in inhibiting bacterial growth due to their heightened capacity to induce oxidative stress. The greater stability and geometrical shape of CuO NPs were disclosed as important features associated with bacterial cell toxicity. SEM and TEM images confirmed that both NPs caused membrane disruption, altered cell morphology, and pronounced membrane vesiculation, a distinctive feature of bacteria dealing with stressor factors. Finally, Cu 2 O and CuO NPs effectively decreased the biofilm-forming ability of the Cu 2+ -resistant UKR strains as well as degraded pre-established biofilm, matching NPs' antimicrobial performance. Despite the similarities in the mechanisms of action revealed by both NPs, distinctive behaviours were also detected for the different species of wild-type Pseudomonas analysed. In summary, these findings underscore the efficacy of nanotechnology-driven strategies for combating metal tolerance in bacteria.

The weed Solidago canadensis L. poses a global threat to the environment as it spreads uncontrollably on roadsides, in forests, fields, meadows, and farmland. Goldenrod emits toxic substances that suppress other plants on the site, displacing wild ones. Thus, goldenrod conquers huge areas very quickly. The use of herbicides and mechanical methods does not solve the problem of the spontaneous spread of goldenrod. On the other hand, many scientists consider goldenrod as a valuable source of biologically active substances: flavonoids, phenolic compounds, vitamins, etc. In this study, we consider Solidago plants as a promising, free (cheap), and renewable substrate for the production of methane gas. The goal of the study was to identify the main patterns of degradation of the Solidago canadensis L. plant by methane-producing and sulfate-reducing bacteria with methane gas production and simultaneous detoxification of toxic copper. The composition of the gas phase was monitored by gas chromatography. The pH and redox potential parameters were determined potentiometrically; metal concentrations were measured by photometry. The concentration of flavonoids, sugars and phenolic compounds in plant biomass was determined according to well-known protocols. As a result of the study, high efficiencies of methane degradation in the Solidago plant and copper detoxification were obtained. Methane yield has reached the value of 68.2 L kg -1 TS of Solidago canadensis L. biomass. The degradation coefficient ( K d ) was also high at 21.4. The Cu(II) was effectively immobilized by methanogens and sulfate reducers during the goldenrod degradation at the initial concentrations of 500 mg L -1 . Thus, a new method of beneficial application of invasive plants was presented. The result confirms the possibility of using methanogenic microorganisms to produce methane gas from invasive weeds and detoxification of toxic metals.

This study presents high-quality draft genome assemblies of six bacterial strains isolated from the roots of wheat grown in soil contaminated with cadmium. The results of this study will help to elucidate at the molecular level how heavy metals affect interactions between beneficial rhizobacteria and crop plants., (Copyright © 2020 Hovorukha et al.)

Environmental copper pollution causes major destruction to ecological systems, which require the development of environmentally friendly biotechnological, in particular, microbial methods for copper removal. These methods rely on the availability of microorganisms resistant to high levels of copper. Here we isolated four bacterial strains with record resistance to up to 1.0 M Cu(II). The strains were isolated from ecologically diverse soil samples, and their genomes were sequenced. A 16S rRNA sequence-based phylogenetic analysis identified that all four isolates belong to the genus Pseudomonas . Particularly, strains UKR1 and UKR2 isolated from Kyiv region in Ukraine were identified as P. lactis and P. panacis , respectively, and strains UKR3 and UKR4 isolated from Svalbard Island in the Arctic Ocean and Galindez Island in Antarctica, respectively, were identified as P. veronii . Initial in-silico screening for genes encoding copper resistance mechanisms showed that all four strains encode copper resistance proteins CopA, CopB, CopD, CopA3, CopZ, as well as two-component regulatory system CusRS, all known to be associated with metal resistance in Pseudomonas genus. Further detailed studies will aim to characterize the full genomic potential of the isolates to enable their application for copper bioremediation in contaminated soils and industrial wastewaters., Competing Interests: The authors have no competing interests., (© 2020 The Author(s).)

The purpose ofthe work was to study the regularities ofFe(III) compounds reduction under the conditions of limited aeration by the strain Citrobacterfreundii Ml-31.1/1, and to assess the role ofFe(II)-reducing bacteria (FRB) in iron compounds transformation in ecosystems. The following methods were used: cultivation of microorganisms under the conditions of limited aeration, colorimetric determination ofbiomass and Fe(III) and Fe(I) compounds concentra- tion, the potentiometric measuring ofpH and Eh, gas chromatography. Results: Thermody- namic calculations of microbial interaction with iron compounds were experimentally verified The regularities of Fe(III) and Fe(I) compounds transformation by the model strain Citro- bacterfreundii Ml-31.1/1, isolatedfrom the typical mid-latitude ecosystem -river sludge were obtained. The balance ofiron compounds redistribution in cells and in the extracellularfraction was established Conclusions: The results obtained are the basis to assume that non-specific interaction of microorganisms with iron may significantly influence transformation of iron. Thermodynamic prognosis allows to carry out targeted regulation of microbial metabolism.

Multi-resistant to extreme factors spore-forming bacteria of Bacillus genus are isolated from hypersaline environments of the Crimea (Ukraine) and the Dead Sea (Israel). Phylogenetic analysis showed distinction of dominating extremophilic culturable species in studied regions. In Crimean environments they are B. mojavensis and B. simplex, in the Dead Sea ecosystem--B. subtilis subsp. spizizenii, B. subtilis subsp. subtilis, B. licheniformis and B. simplex. Isolates are simultaneously halotolerant and resistant to UV radiation. Strains isolated from the Dead Sea and the Crimea environments were resistant to UV: LD90 and LD99.99 made 100-170 J/m2 and 750-1500 J/m2 respectively. Spores showed higher UV-resistance (LD99.99-2500 J/m2) than the vegetative cells. However the number of spores made 0.02-0.007% of the whole cell population, and should not significantly affect the UV LD99.99 value. Isolates of both environments were halotolerant in the range of 0.1-10% NaCl and thermotolerant in the range of 20-50 °C, and didn't grow at 15 °C. Survival strategy of spore-forming bacteria from hypersaline environments under high UV radiation level can be performed by spore formation which minimize cell damage as well as efficient DNA-repair systems that remove damages.

Microbial communities of the Ecuadorian Andes and volcano Tungurahua were shown to be super resistant to representative toxic metals. Maximum permissible concentrations of toxic metals were 100 ppm of Hg2+, 500 ppm of Co2+ and Ni2+, 1000 and 1500 ppm of Cr(VI), 10000 and 20000 ppm of Cu2+. The effect of metal concentration increasing on the biomass growth, CO2 and H2 synthesis was investigated. Two types of response of microbial communities on the increasing of toxic metals concentrations were discovered. The first type of response is the catastrophic inhibition of microbial growth. The second type of response is the absence of microbial growth inhibition at certain metal concentration gradient. The succession of qualitative structure of Ecuadorian microbial communities was shown for the first time. Bacteria, yeasts and finally fungi consistently dominate in the microbial community at the Cu2+ concentration raising. Microorganisms resistant to ultra-high concentrations of toxic metals (e.g., 3000 ... 20000 ppm of Cu2+) were isolated from Ecuadorian ecosystems. These microorganisms are able to accumulate toxic metals.

The widespread of Fe(III)-reducing microorganisms in natural ecosystems of Ecuador of La Favorita, Tungurahua volcano and Papallacta areas was experimentally proved. High efficiency of microbial precipitation of soluble iron compounds was also demonstrated. Obtained results indicate the potential ability of Fe(III)-reducing microorganisms to influence the formation of carbon and iron vector fluxes in ecosystems, as well as development of effective biotechnologies of water purification from iron compounds.

In this paper it was given the effect of p-nitrochlorobenzene (NCB) on the homeostasis quantitative parameters of cave clays microbial communities from Western Ukraine and Abkhazia (Mushkarova Yama, Kuybushevskaya) and soils of Ecuador tropical ecosystems. For these microbial communities were determined maximum permissible concentrations and types of responses on xenobiotic. Microbial communities of Mushkarova Yama cave clays and rainforest soils of Ecuador were characterized by the first type of response. Microbial communities of Kuybushevskaya clays and mountain jungles of Ecuador were characterized by the second type of response. Maximum permissible concentration of NCB for Mushkarova Yama was 200 mg/l, for the other studied microbial communities--300 mg/l. It was shown, that microbial communities were not only highly resistant to NCB but also interacted with it by destroying this xenobiotic and decreasing its concentration in 4 times.

34 strains of aerobic chemoorganotrophic microorganisms were isolated from 23 soil and plant samples selected from highland biotopes of Ecuador-Andes massif (Papallacta, 4020 m), ash at the foot of the volcano Tungurahua, mountainous jungle (La Favorita, 1600 m), as well as in humid tropic botanical garden (state Puyo, 950 m). In mountain jungle samples the high number of bacteria--10(5)-10(7) CFU/g of sample were represented by 2-5 morphotypes. In highland (4020 m) samples the bacterial counts made from 10(2) to 10(7) CFU/g of sample. The current study describes resistance of isolated strains to high salinity, UV radiation and toxic metal ions. The majority of isolated strains were halotolerant. Isolates from volcanic ash showed high resistance level to UV radiation--LD99,99 made 1000-1440 J/m2; resistance level for isolates from the soil of Puyo Botanical Garden and isolates from rock lichen (Papallacta) LD99,99 made 1160 and 800 J/m2 respectively. Strains isolated from mountain jungle (La Favorita) showed lower UV-resistance. In highland biotopes of Ecuador occurred bacteria resistant to toxic metal ions. The highest resistance to Hg2+ was shown by isolate of lichen from mountain jungle, the maximal growth concentration was 0.025 g/L; to Cr(VI)--by isolate from lichen rock massif--3,0 g/L. Correlation between metal-resistance, halotolerace and UV resistance for studied strains was not detected, probably because of different microbial cell damage/repair mechanisms under the action of these factors.

Antarctic plants are stable specific microenvironments for microbial colonization that are still less explored. In this study, we investigated cultivable heterotrophic bacteria and yeasts dominating in plant samples collected from different terrestrial biotopes near Ukrainian Antarctic Base on Galindez Island, maritime Antarctica. Phylogenetic analysis revealed affiliation of the bacterial isolates to genera Pseudomonas, Stenotrophomonas, Brevundimonas, Sporosarcina, Dermacoccus, Microbacterium, Rothia and Frondihabitans, and the yeast isolates to genera Rhodosporidium, Cryptococcus, Leucosporidiella, Candida and Exophiala. Some ecophysiological properties of isolated strains were determined that are important in response to different stresses such as psychro- and halotolerance, UV-resistance and production of hydrolytic enzymes. The majority of isolates (88 %) was found to be psychrotolerant; all are halotolerant. Significant differences in survival subsequent to UV-C radiation were observed among the isolates, as measured by culturable counts. For the bacterial isolates, lethal doses in the range 80-600 J m⁻² were determined, and for the yeast isolates--in the range 300-1,000 J m⁻². Dermacoccus profundi U9 and Candida davisiana U6 were found as most UV resistant among the bacterial and yeast isolates, respectively. Producers of caseinase, gelatinase, β-glucosidase, and cellulase were detected. To the best of our knowledge, this is the first report on isolation of UV resistant strain D. profundi, and Frondihabitans strain from Antarctica, and on detection of cellulase activity in Antarctic yeast strain C. davisiana. The results obtained contribute to clarifying adaptation strategies of Antarctic microbiota and its possible role in functional stability of Antarctic biocenoses. Stress tolerant strains were detected that are valuable for ecological and applied studies.

Enterobacter hormaechei and Brevibacterium antarcticum strains isolated from ornithogenic soils of Galindez Island (West Antarctica) were investigated for their resistance to Cu2+ cations and for their capacity to Cu2+ uptake from the environment. The studied strains are capable to grow in the concentration range of copper 100-1100 mg/l and to extract 11-75% of Cu2+ from the environment depending on cultivation parameters and copper output concentration in the culture medium.

Fifty (50) strains of Pseudomonas genus have been isolated from the samples of soil, moss and bottom sediments taken on the Galindes, Piterman and Deception Islands (Ukrainian Antarctic station Akademik Vernadsky). Characteristic of the above strains by 84 phenotype features and identification by means of the computer program permitted them to be referred to the species Pseudomonas fluorescens (biovar V.), P. putida (biovars A and B), P. veronii. The belonging of the strain 23 to the species P. veronii has been confirmed by the results of sequence of 16S rRNA. Being grown at low temperatures (4 degrees C) the strains of the above species are characterized by high antagonistic activity as to Gram-positive, Gram-negative bacteria, yeast and microscopic fungi. Cultivation of antagonists at 26 degrees C led to the sharp decrease or complete disappearance of the antagonistic effect.