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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]

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 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]