[Resistance of microorganisms of coastal ecosystems of the Dead Sea to extremal factors].

Such extreme factors as UV radiation, high temperature and salinity, and also the small amount of accessible water have an influence on microorganisms of coastal ecosystems of the Dead Sea. Resistance to these factors of the microorganisms isolated from ecosystems of this region (vertical steep gorge around the Dead Sea, clay-salt plain and black highly mineralized muds) is studied. Aerobic, chemoorganotrophic, thermotolerant, moderately halophilic bacteria which, according to their morphological and physiological properties, are similar to species Gracilibacillus halotolerans, Salimicrobium album and genus Caryophanon have been isolated from these ecosystems. All strains grew at 0-10% of NaCl in the medium (one strain--at 15% of NaCl), in the range of 30-50 degrees C. Resistance to UV radiation has been revealed in all the investigated bacteria Lethal doses of UV (LD90 and LD99.99) for spore-forming strains of genus Gracilibacillus were 100-170 and 1100-1500 J/m2, respectively; for strain Salimicrobium 6t1 (does not form spores)--70 and 400 J/m2; for the strain lt4 (genus Caryophanon), forming filamentous (or trychomes)--150 and 1400 J/m2. Some strains of genus Gracilibacillus had strong antagonistic effect on conditionally pathogenic test cultures Staphylococcus aureus 209p and Candida albicans UCM Y-690. It is conceivable that resistance of microorganisms of coastal ecosystems of the Dead Sea to extreme factors was generated under the influence of abiotic (physical and chemical) factors typical of this region.

[Taxonomical status of the psychrotolerant Antarctic microorganisms].

The aerobic chemoorganotrophic bacteria, dominating in soils and phytocenosis of the Antarctic Region, on combination of morphological and biochemical properties belong to several taxons of Bacteria domain. Gram-negative strains 3189, 3415 (fam. Halomonadaceae, Halomonas sp.) and 3088, 3468, 3469 (fam. Moraxellaceae, Psychrobacter sp.) belong to phylum Proteobacteria, to class Gammaproteobacteria. Gram-negative strains 3294 3392 (Rhizobiales, fam. Methylobacteriaceae, Methylobacterium sp.) relate to class Alphaproteobacteria of this phylum. Gram-positive strains 3179, 3275, 3470, 3471 (fam. Microbacteriaceae, Cryobacterium sp.), 3054, 3058, 3411 (fam. Corynebacteriaceae, Corynebacterium sp.) and 3194, 3398 (fam. Micrococcaceae, Micrococcus sp.) relate to phylum Actinobacteria, class Actinobacteria. Thus, the psychrophilic and psychrotolerant Antarctic bacteria (aerobic chemoorganotrophic) isolated from phytocenosis and soils of polar region are characterized by wide taxonomic variety.

[Synthesis of melanin pigments by Antarctic black yeast].

Five strains of the black yeast similar to Exophiala nigra (Nadsoniela nigra), which we have isolated from the Antarctic biotopes, are studied. At cultivation in a periodic operation the maximum level of absolutely dry biomass in five tested strains constituted 3.2-7.8 g/l of medium, melanin pigment yield being 6-9% of absolutely dry mass of cells. Two highly productive strains have been selected. Pigments of the studied black yeast are water-insoluble, however dissolve in alkali and concentrated acids. The maximum absorption of the yeast pigments was in the range of 220 nm. The above-stated properties of pigments of the investigated yeast correspond to the description of melanin fractions of Nadsoniela nigra and some microscopic mushrooms. The water-soluble melanin-pigments have been obtained after the dialysis of alkaline solution of the pigment. UV-spectra and visible absorption spectra of water solution of melanin-pigments are almost identical to those of initial alkaline solutions. It is shown that the studied yeast are resistant to high concentrations of toxic metals (Hg2+, Cu2+, Co2+, Cr(VI) and Ni2+), and introduction of Co2+ into the cultivation medium leads to the increase of pigments synthesis.

[Temperature range for growth of the Antarctic microorganisms].

The assessment of a temperature range for growth of microorganisms isolated at various temperatures (1-5 degrees C or 30 degrees C) from biotopes of the Antarctic region (soil, grass Deschampcia antarctica, grass Colobanthus, a green moss, crustose black lichens and encrustation biofilm on vertical rocks) is made. From 40 to 70% of the investigated Antarctic microorganisms, irrespective of temperature conditions of their isolation, were capable of growing in a wide temperature range (from 1 degrees C to 30 degrees C), i.e. they are psychrotolerant. In selective conditions (1 degrees C or 5 degrees C) the psychrophilic Antarctic bacteria and yeast are isolated which grew in the range from 1 degrees C to 20 degrees C and did not grow at 30 degrees C. At the same time, among the Antarctic microorganisms isolated in nonselective conditions (at 30 degrees C), almost 50% are capable of growing at the lowest temperature (5 degrees C), and a smaller number of strains--at 1 degrees C. However with a decrease of cultivation temperature the growth lag-phase of the Antarctic bacteria increased. Thus the level of the final biomass of the investigated strains did not depend on cultivation temperature. When comparing the temperature range of growth of the mesophilic Antarctic bacteria and collection strains of the same species isolated more than 10 years ago from the region with a temperate climate, the psychrotolerant forms were also revealed among the latter. So, it is shown that the investigated Antarctic bacteria can exist in the temperature range characteristic of terrestrial biotopes of the Antarctic Region (from 1 degrees C to 10 degrees C).

[Resistance of chemoorganotrophic bacteria isolated from Antarctic cliffs to toxic metals].

Resistance to toxic metals ( Hg2+, Cu2+, Ni2+, Co2+, Cr(VI)) of bacteria isolated from rock lichen samples of vertical cliffs located on the biogeographic polygon of Ukrainian Antarctic Station Akademik Vernadsky (island Galindez) is studied. Among the Antarctic rock microorganisms isolated on nonselective medium (without toxic metals), bacteria able to grow at toxic metal concentrations lethal for the majority of microorganisms (Hg2+, Cu2+, Ni2+, Co2+, Cr(VI)) are found out. The studied bacteria are most resistant to Cr(VI) possessing oxidative properties in concentration range 1.25-20.0 g/l depending on the strain. Maximal metal concentrations, at which the growth of bacteria was possible, was: Ni2+ to toxic metals - 2.0 g/l, Co(2+) - 0.1 g/l. In the presence of metal ions possessing both replacing and oxidative properties the strains grew in a concentration range: Hg(2+) - 0.005-0.05 g/l, Cu(2+) - 0.1-1.25 g/l. The highest toxic effect was shown for mercury ions. One of the isolated Antarctic strains which was superresistant to high toxic metal concentrations (g/l): Cr(VI) - 20.0, Ni(2+) - 2.0, Cu(2+) - 1.25, Co(2+) - 0.1, Hg(2+) - 0.05. Thus, for the Antarctic bacteria isolated from rock damaging or bactericidal toxic metal concentrations are by 2-3 orders higher than for the majority of microorganisms.

[Distribution of psychrophilic microorganisms in terrestrial biotopes of the Antarctic Region].

It is shown that the total number of chemoorganotrophic aerobic microorganisms in the Antarctic Region revealed at 1 degree C and 5 degrees C made from 10(4) up to 10(6) cells/g of plant-soil sample of biotopes: grass Deschampcia antarctica, grass Colobanthus, green mosses, crustose black lichens and a biofilm of accretion on vertical rocks. From 10(6) up to 10(8) cells/g of samples were revealed in the same Antarctic samples at 30 degrees C. At 42 degrees C thermotolerant bacteria were either absent, or their quantity was less than 10(4) cells/g of samples. Thus the fraction (part) of the Antarctic microorganisms, which grow at different temperatures, varied: at 1-5 degrees C their part made from 5 to 15%, and at 30 degrees C--from 10 to 45%. At 15-20 degrees C the growth of both psychrophilic/psychrotolerant, and mesophilic microorganisms was observed. When comparing the results of plating of samples from different climatic zones (the Antarctic Region and Ukraine), it is shown that in the Antarctic biotopes in comparison with biotopes of the zone with temperate climate: (1) the total number of microorganisms is lower, (2) quantity of psychrophilic/psychrotolerant bacteria is higher, (3) quantity of mesophilic microorganisms is less, (4) as a result the part psychrophilic/psychrotolerant microorganisms in the total number of microorganisms is much higher. It is evident, that low temperatures, and also daily cycles of freezing and thawing are factors which limit microbial colonization ofAntarctic biotopes.

[Improvement of the method of isolation of hydrogen-forming bacteria of Clostridium genus].

The method of isolation and quantitative account of pure cultures of obligate anaerobic hydrogen-forming clostridia is improved. A strain of hydrogen-forming bacteria Clostridium sp. BY-11 has been isolated from the association of sporulating bacteria. Quantitative indices of hydrogen synthesis and starch fermentation have been determined when growing the strain in the liquid medium. Concentration of H2 in the gas phase was 49%, microorganisms synthesized 128 1 of H2 from 1 kg of starch, the mass of starch decreased 7 times for 6 days. The mentioned indices for hydrogen synthesis and starch fermentation and for other organic model substrates in the future are the basis for creating the industrial biotechnology for production of hydrogen as the energy carrier under disposal of ecologically dangerous solid food waste.

[Resistance of Antarctic microorganisms to UV radiation].

The paper deals with the samples of microorganisms isolated from biofilms of encrustation of 11 stationary points of monitoring on the vertical rock of biogeographical testing ground (island Galindez, Antarctic Region). They are presented by morphologically various forms of bacteria (n x 10(7) cells in 1g of sample), yeast (n x 10(5)) and fungi (n x 10(4)-10(6)). Threshold and lethal UV dozes for isolated monocultures of the Antarctic microorganisms are determined. The threshold doze of UV radiation which is a measure of ability of a cell to reparation of DNA damages for bacteria was 40-70 J/m2. The lethal UV doze (LD99.99) for bacteria varied within the limits of 200-480 J/m2, for yeast of 700-1200 J/m2. Both pigmented and not pigmented bacteria were resistant to UV radiation. As a rule, Gram-positive bacteria were more resistant to UV than Gram-negative ones. It is shown, that resistance of investigated Antarctic rocky microorganisms to UV radiation is their genetically stable characteristic.

[Producing of molecular hydrogen by association of sporulating microorganisms].

Technologically promising microbe association, consisting of aerobic and anaerobic sporulating bacteria has been isolated. The association synthesizes molecular hydrogen during fermentation of potato and starch. The association was isolated from soil, pasteurized on the boiling water bath. The association destroys potato during 5-7 days with a decrease of mass up to 17.4 times and synthesizes gas consisting of 60% of H2.

[Resistance to UV radiation of microorganisms isolated from the rock biotopes of the Antarctic region].

Microbiological analysis of terrestrial biotopes of the Antarctic Region has shown, that vertical rocks of the Antarctic islands open for the Sun were characterized by special microcenoses. The wide distribution of pigmented microorganisms in the rock Antarctic samples, a higher frequency of their occurrence, the total number and biologic diversity, than in other Antarctic biotopes, has been demonstrated. For the first time the presence of bacteria and yeast, resistant to high doses of UV radiation on the vertical rocks in the Antarctic Region was shown. The lethal doze of UV radiation for the Antarctic pink pigmented Methylobacterium strains exceeded 200-300 J/m2, for coal-black yeast--500-800 J/m2, for red yeast--1200-1500 J/m2. The distinctions in lethal UV effect against strains of Methylobacterium isolated from the regions with different climate have not been found. Probably, adaptation of the rock microcenosis to extreme factors of the environment proceeds by natural selection of microorganisms, which resistance to this factor is genetically determined.

[Microbiological analysis of terrestrial biotopes of the Antarctic region].

Microbiological analysis has been made of 120 samples from biotopes of the western coast of the Antarctic peninsula (Rasmussen cope, Tuxen cope, Waugh mountain), Argentine archipelago islands (Galindez, Skua, Corner, Barchans, Irizar, Uruguay, Cluls, Three Little Pigs, King-George), as well as neighbouring islands (Petermann--on the north, a group of Jalour islands--on the east, Berthelot--on the south-east); and more remote islands (Darboux, Lippmann, Booth). It was found out that the total number of chemoorganotrophic aerobic microorganisms was 10(6) - 10(8) cells/g of soil, that was by 2-3 orders lower than in the regions with temperate climate. One can observe a tendency of decreasing the quantity of chemoorganotrophic microorganisms in the Antartic biotopes (cells/g of a sample) in the following order: soil (1 x 10(7) - 8 x 10(8)), underground part of moss (1 x 10(6) - 5 x 10(7)), grass Deschampsia antarctica (10(6) - 10(8), slit of fresh-water reservoir (10(5) - 10(7)), ground part of moss (10(3) - 10(6)), lichens (10(3) - 10(6)). Representatives of several phylogenetic lines: Proteobacteria (genera Pseudomonas, Methylobacterium, Enterobacter), Firmicutes (genera Bacillus, Staphylococcus), Actinobacteria (genera Brevibacterium, Actinomyces, Streptomyces) have been found in the Antarctic samples. As a rule, genera of bacteria found in the Antarctic Region are widely distributed in different regions of the Earth with temperate climate. Microorganisms similar to the species Exophiala nigra (Issatsch.) Haats et de Hoog 1999, which was first detected 100 years ago by Academician B.L. Isachenko in the Arctic region water, were also isolated from biofilms on vertical rocks of the Galindez Island as well as from the soil of the Irizar Island.

[Screening of yeast-producers of melanin in the Antarctic terrestrial biotopes].

Now it is considered, that melanin is promising for application in medicine and pharmacology. Since black yeast were found in polar regions before, we have carried out screening of yeast-producers of melanin in the Antarctic biotopes. Dark pigmented microorganisms are revealed in 30% of samples from terrestrial biotopes at the western coast of the Antarctic peninsula, on islands of the Argentina archipelago (Galindez, Skua, Corner, Barchans, Irizar, Uruguay, Cruls, Three little pigs, King-George), and also on the neighbouring islands Petermann, Jalour, Berthelot, Darboux and Lippmann. In the Antarctic lichens the occurrence frequency of dark pigmented microorganisms, their total number and biodiversity are significantly higher, than in other Antarctic biotopes. Coal-black yeast are found on the crustose and bushy lichens on vertical rocks, they occur less often in soil, their quantity made 1 x 10(2) - 6 x 10(3)/g of a sample. Coal-black pigments were isolated from two Antarctic strains of yeast. These pigments are identical to melanin according to a complex of specific chemical tests, that is also confirmed by the character of UV-spectra (220-230 nm) and absorption spectra in the visible area (400-800 nm). The output of synthesized pigment/g in strain 36 made more than 10% of biomass amount. So, the yeast synthesizing intensively melanin are revealed in the Antarctic terrestrial biotopes.

[Distribution of bacteria of Methylobacterium genus in the terrestrial biotopes of the Antarctic region].

Methylotrophs distribution has been studied in the terrestrial biotopes (moss, lichen, grass, soil, sludge of lakes) on the islands of Galindez, Barkhans, Irizar, Uruguay, Jalour, Petermann, Berthelot, Cruls, King George, Corner, Skua located in the Pacific sector of the Antarctic Region, as well as in analogous biotopes on the western shore of the Antarctic peninsula Basing on a complex of diagnosis features the isolated pink-pigmented strains, which facultatively use methanol and realize the serine cycle of assimilation of one-carbon compounds, are attributed to Methylobacterium genus. Methylobacterium strains occur more often in mosses, grass Deschampsia antarctica and lichens, than in the soil and lake sludge. Some regions ofAntarctica are comparable by the number of Methylobacterium cells with the same in the regions with moderate climate. An analysis of gene sequences 16S rRNA of the Antarctic methylobacteria with those of GenBank has shown a high extent of similarity with Methylobacterium extorquens (99.4-99.7%). Notwithstanding that the strains of Methylobacterium are resistant to the broad range of extreme factors (gamma-irradiation, UV-irradiation, dehydration), the Antarctic and collection strains of the genus were sensitive to the ions of such heavy metals as Cu, Hg, Cd, Cr (10 mg/l).

[Search for psychrophilic methylotrophic bacteria in biotopes of the Antarctica].

Psychrotolerant bacteria which use obligately methane were found in the moss samples and in soil-vegetation samples in the island part of the Antarctica during the VII expedition (2003) at the station "Akademik Vernadsky". The number of methane-oxidizing bacteria in the samples from the Antarctica (101- 10(3)/g of the sample) was lower than in the samples from the regions with moderate climate (10(2)- 106/g of the sample). Psychrotolerant strains of Methylobacteriium genus which use facultatively methanol were found in the bottom sediments of the fresh-water and Krasnoye lakes, as well as in the soil-plant samples. The psychrophilic strain which is probably a new species of the genus Methylobacterium has been isolated from one soil-plant sample from the Antarctica at 10 degrees C. It is established that most collection mesophilic strains of Methylobacterium, which have been isolated from the soil and plant phyllosphere in Ukraine, also could grow at 10 degrees C.

[Extraction of a broad range of metals from sewage in the city of Kyiv by mixed microbe communities]. / Izvlechenie shirokogo spektra metallov iz stochnykh vod g.Kieva smeshannymi mikrobnymi soobshchestvami.

Accumulation of a wide range of metals by the "mixed microbe communities" (MMC) from Kyiv sewage treated in the air tank has been studied. MMC is a mixture of one or more synthrophical associations, such as microorganisms of fermented metantank deposit and cow manure. The exposure being 48 h and weight ratio of the phases MMC : sewage being 1:50, MMC lower the concentration of Ca, Fe, Zn, Cc, Au in sewage by 1 order; Cr, Mn, Co, Ag, Cd, Ba, Sm, Hf, Th--by 2 orders; Sc, Sb, La--by 3 orders. MMC may be used efficiently for deep tertiary treatment of sewage for toxical heavy metals, for extraction of rare-earth and non-ferrous metals from superdiluted solutions and industrial sewage.

[Accumulation of uranium, plutonium and americium by granulated microbial biosorbent]. / Akkumuliatsiia urana, plutoniia i ameritsiia granulirovannym mikrobnym biosorbentom.

A possibility of efficient extraction of 238U, 239Pu and 241Am by microorganisms from solutions with activity 520-3200 Bq/l has been shown on the example of microbial biosorbent (MBS). MBS presents water-resistant granules consisting of living microorganisms and nutrient substances. The ratio MBS:solution being equal to 1:100 and 1:20, microorganisms extracts 98.9 and 99.8% of 238U; 99.1 and 99.8% of 239Pu, 241Am, respectively. The worked out MBC granules may be utilized by burning with the 4-8 decrease of the volume. It is foreseen to use MBS in industrial processes of treatment of liquid radioactive waste (LRW) for uranium and transuranium elements.

[Radionuclide accumulation by a microbial sorbent]. / Akkumuliatsiia radionuklidov mikrobnym sorbentom.

Accumulation of a wide range of radionuclides by the microbial sorbent has been studied. The microbial sorbent represents granules stable in water solutions for a long period of time. The sorbent includes: concentrated biomass of metabolically active microorganisms, sources of carbon and energy, phosphorus, nitrogen, etc. Availability of nutrition sources in the sorbent provides for metabolic activity of microorganisms immobilized in granules. Metabolic activity of the sorbent was characterized. Physico-chemical sorption and metabolic activity of microorganisms lead to the extraction of a wide spectrum of radionuclides (51Cr, 54Mn, 60Co, 90Sr, 134Cs, 137Cs, 140La, 144Ce, 226Ra, 83Rb) from liquid radioactive waste. The extraction factor for some radionuclides was 10(5)-10(6). The waste sorbent may be utilized. Absence of water phase in the ash concentrate permits the radionuclides to be buried in borosilicate or volcanic glass (accepted time of existence 10(5)-10(7) years). The sorbent may be used to create new biotechnologies of radionuclide accumulation from water solutions.

[n-Chloroaniline transformation by Escherichia coli under anaerobic conditions]. / Transformatsiia n-khloranilina, vyzyvaemaia Escherichia coli v anaérobnykh usloviiakh.

In a medium without oxygen in the presence of nitrates, E. coli transforms p-chloranilin (p-CA) to yield a more hydrophilic compound which cannot be extracted with an organic solvent from water. The conditions for consecutive transformation of p-nitro-chlorobenzene (p-NCB) and p-CA have been determined: the reaction p-NCB leads to p-CA is inhibited by nitrates, p-CA transformation occurs in the presence of nitrates in the medium and depends on their concentration.

[Anaerobic glove box]. / Anaérobnyi perchatochnyi boks.

Anaerobic conditions can rapidly be created in a box designed for working with obligate anaerobic organisms by driving out the air with an inflatable ball. The box is fitted with a device for sterilising a microbiological loop.