[Regulation of sulfates, hydrogen sulfide and heavy metals in technogenic reservoirs by sulfate-reducing bacteria].

Sulfate-reducing bacteria Desulfovibrio desulfuricans Ya-11 in the presence of sulfates and organic compounds in the medium reduce sulfates to hydrogen sulfide (dissimilatory sulfate reduction). Heavy metals in concentration over 2 mM inhibit this process. Pb2+, Zn2+, Ni2+, Co2+, Fe2+ and Cd2+ ions in concentration 1-1.5 mM display insignificant inhibiting effect on sulfate reduction process, and metals precipitate in the form of sulfides. At concentrations of heavy metals 2-3 mM one can observe a decrease of sulfates reduction intensity, and a percent of metals binding does not exceed 72%. Obtained results give reason to confirm, that sulfate-reducing bacteria play an important role in regulation of the level of sulfates, hydrogen sulfide and heavy metals in reservoirs and they may be used for purification of water environment from these compounds.

[Metabolism of carbohydrates in the cells of green sulphur bacteria Chlorobium limicola Ya-2002].

The nature of carbohydrates that accumulate in the cells of photosynthetic green sulphur bacteria of Chlorobium limicola Ya-2002 has been investigated. It is shown by infra-red spectrometry, that carbohydrates accumulated in the cells of bacteria are identical (by 90-95%) to glycogen of the bull liver. Exogenous glucose, saccharose, maltose, did not stimulate formation of glycogen. Growth of glycogen level in the cells of bacteria was observed at addition of acetate or piruvate in the conditions of bacteria cultivation in the light and in the presence CO2 and H2S in the environment. Washed cells of C. limicola Ya-2002 did not use glucose of the environment neither in the conditions of illumination nor in darkness, however acetate and piruvate are actively used in the light. During incubation of the washed cells in darkness the level of glycogen fell down approximately three times. Its amount during cells incubation in the light did not change. The decline of glycogen level in cells during their incubation in darkness was accompanied by piling up of carbonic acids in the environment acetate prevailing among them.

[Physilogical and biochemical properties of bacteria of Chromatium genus, isolated from water bodies enriched with hydrogen sulfide].

Pure cultures of purple sulfur bacteria, which were attributed to genus Chromatium, were isolated from water bodies of the Yavoriv sulfur deposit. Both cultures perform anoxygenic photosynthesis and contain bacteriochlorophyll a and carotenoids of spirilloxanthin group. Isolated bacteria grow photolithoauthotrophically, photolithoheterotrophically and photoorganoheterotrophically. Hydrogen sulphide, sulfur and thiosulfate were used as inorganic electron donors. Bacteria were resistant to high hydrogen sulphide concentrations and assimilated it effectively in the process of anoxygenic photosynthesis. Isolated bacteria are considered as promising models for creation of biotechnologic ecosystems, which will be used for treatment of media polluted with sulfur compounds.

[Purple sulfur bacteria isolated from reservoirs of the Yavoriv sulfur deposit].

Three pure cultures of purple sulfur bacteria were isolated from reservoirs of the Yavoriv sulfur deposit. The studying of their morphology, cytology and physiology has confirmed the belonging of these bacteria to Chromatiaceae family and has allowed identifying them as Thiocapsa sp., Lamprocystis sp. and Chromatium sp.

[Sulfate-reducing bacteria in reservoirs of the Yavoriv sulfur field].

Fifteen cultures of bacteria which perform dissimilation sulfate reduction have been isolated from the reservoirs of the Yavoriv sulfur deposit. Electron-microscopic investigations have shown that the cells of all cultures are of vibroid, spiral and bacillary form. They form no spores. They grow in the medium with sulfates and lactates and do not use propionate and acetate. In the medium with lactate all the cultures accumulated acetate in the medium. Cells of all the studied bacteria contain desulfoviridine. On the basis of obtained characteristics the isolated bacteria are referred to genus Desulfovibrio.

[Pigments of green sulfur bacteria isolated from reservoirs of Iavoriv sulfur deposit]. / Pihmenty zelenykh sirkobakterii, vydilenykh iz vodoim Iavorivs'koho sirchanoho rodovishcha.

The enormous amount of hydrogen sulfide (up to 11 mg/ml) is present in the Yavoriv sulfur deposit reservoirs owing to sulfur reductive bacteria activity. As a consequence the ecological situation is badly affected and requires recovering. The biological H2S decomposition by photosynthetic sulfur bacteria, which use the hydrogen sulfide as electron donor during photosynthesis, can be one of the possible ways of this toxic substance destruction. The qualitative and quantitative analysis of photosynthetic pigments composition that derived from green photosynthesizing sulfur bacteria from reservoirs of Yavoriv sulfur deposit is carried out. It was fixed that Pelodictyon sp., Chlorobium sp. and isolated consortia "Pelochromatium sp." contain the bacteriochlorophyll c and d. All the isolated cultures contained bacteriochlorophyll a in trace amounts. The obtained photosynthetic pigments (bacteriochlorophylls, carotenoids) were recognized by their absorption spectra in the visible and far-red region and by their quantity. The difference was not essential. All investigated cultures of isolated bacteria contain some carotenoid the Chlorobium sp. and obtained consortia possesses isorenieratene. The absorption maxima of extracted pigments from young cultures of isolated green sulfur bacteria are more definitely displayed than those from old cultures. Investigations of phototrophic sulfur bacteria were carried out in Ukraine up to now. Ecological problem that occurred in the Yavoriv sulfur deposit as a result of the deposit exploitation caused a necessity of the investigation of photosynthetic sulfur bacteria and bacterial photosynthesis mechanism. The photosynthetic pigments nature identification will promote the fast and precise identification of the new forms of photosynthetic sulfur bacteria and will extend our knowledge about their role in the anoxygenic photosynthesis.

[Biodegradation of oil hydrocarbons by Candida yeast]. / Biodegradatsiia vuhlevodniv nafty drizhdzhamy rodu Candida.

Capability of 14 yeast species to utilize oil hydrocarbons has been analyzed. All strains utilized oil hydrocarbons as a single carbon source. Four strains-destructors that are characterized by higher growth in the presence oil in cultivation medium have been chosen among them. Peroxisomes participation in utilization of oil hydrocarbons by strains-destructors has been shown. Availability of peroxisome key enzymes are characteristic of these strains grown in cultivation medium with oil. Numerous peroxisomes available in the cells of some strains grown in oil cultivation medium have been demonstrated. Utilization of a wide spectrum of oil hydrocarbons has been revealed in all four strains. Two strains are promising to be used for environment purification from oil pollution.

[The effect of ethanol on the fatty acid content of Saccharomyces cerevisiae and Schwanniomyces occidentalis cells]. / Vplyv etanolu na vmist zhyrnykh kyslot u klitynakh Saccharomyces cerevisiae i Schwanniomyces occidentalis.

The influence of ethanol on fatty acid content in the cells of the Crabtree-positive yeast Saccharomyces cerevisiae and Crabtree-negative Schwanniomyces occidentalis has been studied. It was shown, that S. cerevisiae grown in the medium with 2% glucose was characterized by the lower level of fatty acids in comparison with Schw. occidentalis, while in the medium with 1.5% ethanol no significant difference was found between the contents of fatty acids in the cells of the yeasts investigated. The level of fatty acids in S. cerevisiae is reduced, but that in Schw. occidentalis is enhanced when ethanol was added to the medium containing 2% glucose. The growing of both yeast species in the medium with 0.1% glucose and ethanol leads to the increase of the amount of esterified fatty acids. The level of nonesterified fatty acids increased in Schw. occidentalis and decreased under the same conditions in S. cerevisiae. However, the content of nonesterified fatty acid in S. cerevisiae grown in the medium with 0.1% glucose and 1.5% ethanol was 6.2 times higher as compared with those growing in the medium containing 2% glucose and 1.5% ethanol.

[The effect of glucose on the fatty acid level in Saccharomyces cerevisiae and Schwanniomyces occidentalis cells]. / Vplyv hliukozy na riven' zhyrnykh kyslot u klitynakh Saccharomyces cervisiae i Schwanniomyces occidentalis.

The influence of glucose on fatty acid contents in the cells of yeast Saccharomyces cerevisiae and Schwanniomyces occidentalis has been studied. It was shown that fatty acid contents in Schw. occidentalis was enhanced with the increase of glucose concentration in the medium. The increase of glucose concentration in the medium during respiro-fermentative growth phase reduces the level of C18 in unsaturated fatty acids of S. cerevisiae; the increase of fatty acids content in total lipids and nonetherified fatty acids was observed under the same conditions in the respiratory phase. It was established that during the growth of S. cerevisiae in the medium with 0.1% glucose the level of nonetherified fatty acids was higher and with 4% glucose--lower in comparison with Schw. occidentalis. The correlation of nonetherified and etherified fatty acid levels in S. cerevisiae is higher in comparison with Schw. occidentalis grown under the same conditions.