Search

The aim of the study was to investigate the number of different groups of microorganisms in soil samples from sites of feed and nesting activity of Larus dominicanus (Galindez Island, the maritime Antarctic) and to characterize the physiological and biochemical properties of isolated microorganisms. Methods. In the work standard microbiological and biochemical research methods were used (cultural, microscopy methods, determination of enzymatic activity). Genomic DNA was isolated by soft lysis. The 16 S rRNA gene was amplified using universal primers 27F and 1492R. Identification of isolates was performed based on the determination of the 16 S rRNA gene sequence, physiological and biochemical properties. Results. The number of microorganisms of different groups in soil samples from sites of food and nesting activity of Larus dominicanus (Galindez Island, the maritime Antarctic) was established. 74 isolates of bacteria were isolated. Isolate 2U-K-37, that was isolated from upper layer of soil, and isolate 2B-K-54, that was isolated from a depth of 2–5 cm, were characterized by amylase, lipase, phospholipase, protease activities, the ability to form exopolysaccharides.They were identified by sequencing of the 16 S rRNA gene, physiological and biochemical properties as Pedobacter sp. 2U-K-37 and Pseudarthrobacter sp. 2B-K-54. In the soil samples from sites of feed and nesting activity of Larus dominicanus microorganisms that metabolize nitrogen of organic compounds were the most numerous. Oligotrophic microorganisms and microorganisms that metabolize nitrogen of inorganic compounds were less numerous. The number of microorganisms of groups in the samples from the soil surface and lower layers differed statistically significant. Isolated and identified obligate psychrophilic strain Pedobacter sp. 2U-K-37 and psychrotolerant strain Pseudarthrobacter sp. 2B-K-54 are moderate halophiles that are able to hydrolyze starch, gelatin, tween-20 and synthesize exopolysaccharides.

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...+30ºC 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.

The influence of ferrum (III) citrate added to the cultivation medium, on the reduction of sulfate, nitrate, and nitrite ions by sulfate-reducing bacteria Desulfovibrio desulfuricans IMV K-6, Desulfovibrio sp. Yav-6, and Desulfovibrio sp. Yav-8 isolated from Yavorivske Lake was studied. It was established that ferrum (III) citrate inhibits the biomass accumulation, SO42- reduction, and H2S production by the bacteria after addition of 1.74–3.47 mM Na2SO4×10 H2O and 1.74–10.41 mM FeC6H5O7 to the medium, in comparison with the growth and level of the reduction of sulfate ions by bacteria in the medium supplemented with only Na2SO4×10 H2O. At conditions of the bacteria cultivation in the presence of an equimolar amount (3.47 mM) of Na2SO4×10 H2O and FeC6H5O7, they reduced 2.5−2.7 times more Fe(ІІІ) than SO42- with Fe2+ production at a concentration 2.4−2.7 times greater than H2S. FeC6H5O7 inhibited growth, NO3- or NO2- reduction and NH4+ production by the bacteria in the presence of 1.74−3.47 mM NaNO3 or NaNO2 and 1.74−10.41 mM FeC6H5O7 in the medium, compared to the growth and level of nitrate or nitrite ions reduction in the medium with only NaNO3 or NaNO2. In the medium with the same initial content of 3.47 mM NaNO3 and 3.47 mM FeC6H5O7, the bacteria reduced 1.4 times more NO3- than Fe(ІІІ), with NH4+ production at concentration 1.1 times higher than that of Fe2+. In the medium with 3.47 mM NaNO2 and 3.47 mM FeC6H5O7, the cells reduced 1.4−1.6 times more Fe(ІІІ) than NO2-, with Fe2+ production at concentra­tion 1.5−1.6 times higher than NH4+. Ferrum (III) citrate had more inhibitory effect on the dissimilatory reduction of sulfate by the bacteria than of nitrate and nitrite ions, since the SO42- reduction by the bacteria at its presence in the medium decreased 2.0−4.7 times. The reduction of NO3- and NO2- decreased only 1.3−1.9 and 1.7−3.1 times, respectively, as compared with their reduction in the media with only Na2SO4×10 H2O, NaNO3 or NaNO2. Despite the fact that the reduction by cells of 1.74−10.41 mM Fe(III) in the media with Na2SO4×10 H2O, NaNO3 or NaNO2 decreased 1.1−2.1, 1.6−2.7 and 1.1−2.5 times, respectively, compared with its reduction in the medium with only FeC6H5O7. The investigated strains of bacteria were resistant to high concentrations of ferrum (III) citrate and, therefore, can be applied in the technologies of complex environment purification from pollution with ferrum, sulfur, and nitrogen compounds.

Phototrophic purple non-sulfur bacteria (PNSB) mineralize organic waste. In media with different organic substances they are metabolized from simple aliphatic organic acids to complex polysaccharides. These bacteria can produce H2, indole-3-acetic acid and 5-aminolevulinic acid. PNSB purify waters from hydrogen sulfide and, as components of ecosystem trophic chains, participate in process of sulfur cycle. The ability of these bacteria to denitrification is of particular interest to specialists because nitrates concentrations in industrial effluents are often much higher than the maximum permissible concentrations. The use of industrial, agricultural and household wastes to produce PNSB biomass is economically profitable. Therefore, the aim of our work was to investigate the influence of wastewater of the yeast plant and the water of the settler № 3 filtrate of the Lviv Solid Household Waste Landfill (LSHWL) on the biomass accumulation by PNSB Rhodopseudomonas yavorovii IMV B-7620 and the changes in the composition of these waters in the process of cultivation of the investigated bacteria. Bacteria were grown for 21 days anaerobically at an illumination intensity of 200 lux in 500 ml flasks at +29 ... +30 °C. The wastewater of the yeast plant and the water of the settler № 3 filtrate of the LSHWL were used as the cultivation media. Water was diluted at 10; 30; 50; 100 times. In water, diluted at 10 times, the pH, total ferrum content, Ca2+, Mg2+, Cl-, NO3-, NO2-, SO42-, HS- and chemical oxygen demand (COD) were determined. The biomass of bacteria was measured turbidimetrically at λ = 660 nm. The concentration of HS- was determined spectrophotometrically (λ = 665 nm) by the formation of methylene blue. The content of sulfate ions was determined turbidimetrically (λ = 520 nm) after their precipitation with barium chloride. The concentrations of Ca2+ and Mg2+ were determined titrometrically by reaction with trilon B; Na+ and K+ were analyzed by flame emission spectrometry method (lK = 768 nm, lNa = 589 nm). The pH of the water was measured potentiometrically. The concentration of Cl- was determined titrometrically by reaction with AgNO3. The concentration of nitrite ions was determined spectrophotometrically by the method of sulfanilic acid diazotization by nitrite ions and the interaction of the formed salt with n-(naphthyl)ethylenediamine dihydrochloride (λ = 540 nm, l = 10 mm). The concentration of nitrate ions was determined spectrophotometrically by the diazotization method. Zinc powder was used as the reducing agent. COD was measured with using of KMnO4. It is characterised the patterns of biomass accumulation by R. yavorovii IMV B-7620 bacteria in the wastewater of the yeast plant and the water of the settler № 3 filtrate of the LSHWL, diluted at 10–100 times. The optimal dilution (at 10 times) of water for bacteria cultivation was selected. Bacteria R. yavorovii IMV B-7620 accumulate biomass of 2.2 g/l during growth in a yeast plant wastewater that is twice as large as the biomass, accumulated by bacteria in the diluted water of the settler № 3 filtrate. The organic compounds oxidation efficiency of the yeast plant wastewater and of the settler № 3 filtrate of LSHWL, determined by chemical oxygen demand, was 42.3 and 65.6 %, respectively, on the 21st day of cultivation. The established possibility of the influence of R. yavorovii IMV B-7620 on the decreasing of the content of total Fe, Ca2+, Mg2+, NO3-, NO2-, SO42-, Cl-, HS- in wastewater has complemented and broadened the understanding of the role of purple non-sulfur bacteria in ecosystems, which can significantly influence on the biogeochemical cycles of these compounds in nature. The results obtained may form the basis for the development of effective biotechnologies for wastewater treatment from hydrogen sulfide, chlorine, ferrum, nitrogen, sulfur compounds with the participation of these microorganisms.

Aim. To investigate the cultural, morphological, physiological and biochemical properties of the isolated chemoorganotrophic heavy metal resistant isolates of bacteria from different samples obtained during the Ukrainian Antarctic expedition in 2019 for further selection of the most resistant to heavy metal compounds and biochemically active substances. Methods. Pure cultures of bacteria were isolated using tryptone soy agar and nutrient agar. Obtained isolates were sown on agar media containing Cu(II) (0.3, 0.1, 1.5, 8, 78 mM), Pb(II) (0.00009, 0.0005, 0.005, 0.05, 0.5 mM), Cr(VI) (0.00096, 0.0096, 0.96, 9.6 mM). The morphological properties of the bacteria were studied using an Axio Lab.A1 Carl Zeiss binocular microscope, an Olympus IX73 inverted microscope with DP-74 digital camera and transmission electron microscopy. Endospores were detected using the Peshkov-Trujillo method. Catalase, oxidase, amylase, lipolytic, protease activities, ability to fix nitrogen were determined. The ability of microorganisms to metabolize organic carbon sources was determined during growth on Hiss medium with different carbohydrates and alcohols. The determination of the physiological properties of obtained isolates was performed using the Remel RapID™ ANA II system. Results. 92 isolates of psychrophilic microorganisms that grew at temperatures 2 °C, 6 °C and 20 °C were isolated from investigated samples. Among the isolated microorganisms, 64 grew on media containing 0.3– 1.6 mM Cu(II), or 0.00009–0.004 mM Pb(II) or 0.01–0.9 mM Cr(VI). 9 isolates of psychrophilic bacteria were resistant to Cu(II) (1.5–78 mM), Pb(II) (0.5 mM), Cr(VI) (0.96–9.6 mM). Morphological, physiological and biochemical properties of 9 multiresistant isolates were described. Conclusions. The physiological and biochemical properties of obtained isolates of An tarctic microorganisms that are resistant to Cu(II) (1.5–78 mM), Pb(II) (0.5 mM), Cr(VI) (0.96–9.6 mM) are determined. Selected isolates of microorganisms are able to use monosaccharides, disaccharides, alcohols as carbon sources; possess urease, protease, lipase, aminopeptidase activities. Selected heavy metal resistant isolates can be used for further investigation and development of technologies for bioremediation of environment.

The selection of strains isolated from technogenically altered ecotopes and resistant to contamination, capable of metabolizing a wide range of pollutants is a task highly relevant for creation of new methods for environmental purification. Sulphur-reducing bacteria of the Desulfuromonas genus carry out dissimilatory reduction not only of S0 but also oxidized forms of metals. Intensity of anaerobic respiration of microorganisms in polluted environments is determined by level of their adaptation to stress factors, in particular, copper (II) compounds. The aim of this work was to investigate the influence of copper (II) chloride on H2S production by Desulfuromonas sp. strains isolated by us from Yavorivske Lake, to determine the efficiency of Cu2+ precipitation by hydrogen sulfide, to analyse the possibility of usage by bacteria of CuCl2 as an electron acceptor of anaerobic respiration and to study the influence of Cu2+ on usage by these microorganisms of ferric (III) citrate, potassium dichromate or manganese (IV) oxide as electron acceptors. Bacteria were grown under anaerobic conditions in Kravtsov-Sorokin medium. To study the influence of Cu2+ on production by bacteria of H2S, their cells were incubated with CuCl2 (0.5–4.0 mM), washed and cultivated in a medium with S0. To determine the level of Cu2+ binding by H2S, produced by bacteria, cells were grown in a medium with CuCl2 (0.5–4.0 mM) and S0. To investigate the ability of bacteria to use copper (II) ions as electron acceptors, they were cultivated in a medium with CuCl2 (1.74–10.41 mM). To study the influence of Cu2+ on usage by bacteria of metal compounds as electron acceptors, their cells were incubated with CuCl2 (0.5–4.0 mM), washed and cultivated in media with C6H5O7Fe, K2Cr2O7 or MnO2 (1.74–10.41 mM). Biomass was determined by the turbidimetric method. In the cultural liquid the content of H2S was determined quantitatively by the spectrophotometric method, qualitatively – presence of Cu2+. Content of CuS in the growth medium was determined by weight method. Desulfuromonas sp. bacteria was revealed to be resistant to 2.0–2.5 mM copper (II) ions. Under the influence of 3.0–4.0 mM CuCl2 in the incubation mixture, sulfidogenic activity of bacteria decreased more than twice. The efficiency of Cu2+ binding in form of CuS by H2S produced by bacteria reached 97.3–100.0% at presence in the medium with S0 of up to 1.5 mM CuCl2. Bacteria used CuCl2 (1.74–10.41 mM) as an electron acceptor in the process of anaerobic respiration. The addition of 2.5–3.0 mM CuCl2 to the incubation mixture caused inhibition of metal reducing activity of cells, growth of all strains in media with 1.74–10.41 mM ferric (III) citrate, potassium dichromate or manganese (IV) oxide as electron acceptors decreased by 2.6 times. Almost complete precipitation up to 1.5 mM copper (II) ions in form of CuS by H2S produced by bacteria and ability to reduce up to 10.41 mM CuCl2, C6H5O7Fe, K2Cr2O7 or MnO2 in the process of anaerobic respiration indicates a high adaptation of the bacteria strains investigated by us to stress factors, in particular, the influence of CuCl2. We have proved the possibility of using Desulfuromonas sp. in biotechnologies for purification of environments with complex contamination from copper (II) compounds.

This article covers the patterns of oxidation of sulfide and thiosulfate ions by bacteria Rhodopseudomonas yavorovii Ya-2016 under different cultivation conditions. In the environments with 1.4–5.6 мМ Na2S2O3, R. yavorovii Ya-2016 bacteria accumulated biomass of 1.4–1.6 g/l, which was higher than biomass (1.2-0.6 g/l) accumulated by the bacteria with the same concentrations of Na2S × 9H2O. The efficiency of oxidation of 1.4, 2.8, 5.6 мМ sulfide- and thiosulfate-ions as donors of electrons by the bacteria equaled 97.4, 42.6, 18.7 and 68.8, 28.0, 3.7%, respectively. As a result of bacterial oxidation of 1.4 мМ hydrogen sulfide and sodium thiosulphate in the environment accumulation of 0.13–1.30 мМ sulfate-ions occurs, and the element sulfur becomes an intermediate metabolite in the environment with Na2S×9H2O. R. yavorovii Ya-2016 bacteria are capable of using sulfate-ions as a single source of sulfate at increase in photptrophs. In the environment with 2.5 мМ sulfate-ions concentration the bacteria biomass was 1.4 g/l, the bacteria assimilated 17.7% of sulfates. Because purple non-sulfur bacteria R. yavorovii Ya-2016 are capable of using sulfide-ions as donors of electrons of anoxygenic photosynthesis and using sulfate-ions as a single source of sulfate, they could be successfully used in the technologies of remediating the environment from compounds of sulfur.

Sulfate reducing bacteria, capable to reductive transformation of different nature pollutants, used in biotechnologies of purification of sewage, contaminated by carbon, sulfur, nitrogen and metal compounds. H2S formed by them sediment metals to form of insoluble sulfides. Number of metals can be used by these microorganisms as electron acceptors during anaerobic respiration. Because under the influence of metal compounds observed slowing of bacteria metabolism, selection isolated from technologically modified ecotops resistant to pollutions strains is important task to create a new biotechnologies of purification. That’s why the purpose of this work was to study the influence of potassium dichromate, present in medium, on reduction of sulfate and nitrate ions by sulfate reducing bacteria Desulfovibrio desulfuricans IMV K-6, Desulfovibrio sp. Yav-6 and Desulfovibrio sp. Yav-8, isolated from Yavorivske Lake, to estimate the efficiency of possible usage of these bacteria in technologies of complex purification of environment from dangerous pollutants. Bacteria were cultivated in modified Kravtsov-Sorokin medium without SO42- and FeCl2×4H2O for 10 days. To study the influence of K2Cr2O7 on usage by bacteria SO42- or NO3- cells were seeded to media with Na2SO4×10H2O or NaNO3 and K2Cr2O7 at concentrations of 1.74 mM for total content of electron acceptors in medium 3.47 mM (concentration of SO42- in medium of standard composition). Cells were also seeded to media with 3.47 mM Na2SO4×10H2O, NaNO3 or K2Cr2O7 to investigate their growth in media with SO42-, NO3- or Cr2O72- as sole electron acceptor (control). Biomass was determined by turbidymetric method, content of sulfate, nitrate, dichromate, chromium (III) ions, hydrogen sulfide or ammonia ions in cultural liquid – by spectrophotometric method. It was found that K2Cr2O7 inhibits growth (2.2 and 1.3 times) and level of reduction by bacteria sulfate or nitrate ions (4.2 and 3.0 times, respectively) at simultaneous addition into cultivation medium of 1.74 mM SO42- or NO3- and 1.74 mM Cr2O72-, compared with growth and level of reduction of sulfate or nitrate ions in medium only with SO42- or NO3- as sole electron acceptor. Revealed that during cultivation of bacteria in presence of equimolar amount of SO42- or NO3- and Cr2O72-, last used by bacteria faster, content of Cr3+ during whole period of bacteria cultivation exceeded content H2S or NH4+. K2Cr2O7 in medium has most negative influence on dissimilatory reduction by bacteria SO42- than NO3-, since level of nitrate ions reduction by cells in medium with NO3- and Cr2O72- was a half times higher than level of sulfate ions reduction by it in medium with SO42- and Cr2O72-. The ability of bacteria Desulfovibrio sp. to priority reduction of Cr2O72- and after their exhaustion − NO3- and SO42- in the processes of anaerobic respiration can be used in technologies of complex purification of environment from toxic compounds.

Simultaneous operations in case of laparoscopic cholecystectomy constitute 0.5-16% of the total surgery. The aim of the study was to analyze the results of laparoscopic simultaneous cholecystectomies combined with surgical pathology. Among the 216 patients, 58 (26.85%) cases of simultaneous operations were performed with combined access and 158 (73.15%) cases of simultaneous operations performed in open way. The study is indicative of reasonability of simultaneous operations in case of combined surgical pathology. Severe specific complications are prevented, a positive medical and social effect and efficiency is presents as compared to performing two or three separate surgeries.

New strains of sulfate-reducing bacteria were obtained from human intestine. These bacteria are vibrio-like (strains SRB Vib-1, SRB Vib-2, SRB Vib-3) and short rod-like (strains SRB Rod-4 and SRB Rod-5) forms. Growth of these strains of bacteria, usa ge of sulfates by bacteria and their production of hydrogen sulfide were studied. The strains of sulfate-reducing bacteria SRB Vib-1, SRB Vib-2, SRB Vib-3 more intensively accumulate biomass compared with strains SRB Rod-4 і SRB Rod-5. The SRB Vib-1 and SRB Vib-2 strains grow most intensively. Accumulation of bacterial biomass (3.8 g/l) is the highest on the third day of cultivation, and after that a stationary growth phase began. The SRB Vib-3 strain of bacteria accumulates 2.89 gram per liter of biomass on the third day of bacteria cultivation. Maximal biomass of SRB Rod-4 and SRB Rod-5 bacteria strains ranged from 2.59 to 3.25 gram per liter on the eighth day of cultivation. The obtained sulfate-reducing bacteria intensively use sulfate ions and produce hydrogen sulfide. The SRB Vib-1, SRB Vib-2, SRB Vib-3 strains produce from 2.99 mM to 3.12 mM of hydrogen sulfide. The rod-shaped strains of sulfate-reducing bacteria use sulfate ions and produce hydrogen sulfide less intensively in the presence of sulfates.

Lanthanide β-diketones and their derivatives are extensively studied coordination compounds, due to their luminescent properties and many possible applications. The tetrakisNd(III) complex with phosphorylated sulfonylamides derivatives of β-diketones was synthesized. The X-ray diffraction showed that the compound of formula {[Na[Ln(SP)4]} n (SP = C6H5S(O)2NP(O)(OCH3)2; Ln = Nd(III) crystallize in the monoclinic P21/c space group with the following unit-cell parameters: a = 22.006(4)A, b = 11.075(2)A, c = 22.334(5)A, and β = 118.71(3)°. The molecular structure of the investigated compound is polymeric. The lanthanide ions as well as the sodium ions are coordinated by sulfonyl and phosphoryl groups of the ligand, and because of the bridging behavior, link different units of the polymer. High-resolution absorption, emission, and excitation spectra of neodymium crystals were measured at 298, 77, and 4K temperatures. The sensitized emission of [Na[Nd(III)(L)4]} n chelate in the IR range of the spectrum was recorded. This kind of the compounds can be used in organic light emitting diodes in compact display technology. The spectral characteristic of the compound is controlled by donor–acceptor properties and electron-hole transporting chemical groups. Those factors affect the energy level location, energy transfer (ET), electron–phonon coupling, and finally the luminescence quantum yield. The optical behavior of the title compound was characterised by crystal field (CF), correlation crystal field (CCF), and electron transition probability calculations. X-ray structural data and the nephelauxetic effect check the role of the character of the bonding. The IR spectra were used to analyze the vibronic components in electronic transitions. The role of ligands, singlet and triplet states in energy transfer, are discussed. The ET mechanism and emission quenching pathways are proposed. Some spectroscopic parameters will be compared with earlier reported NaNdWo4 × H2O (Wo = CCl3 CONPO(OCH3)2).

We report the isolation of mutant strains of the methylotrophic yeast Hansenula polymorpha that are able to efficiently oxidize ethanol to acetaldehyde in an intact cell system. The oxidation reaction is catalyzed by alcohol oxidase (AOX), a key enzyme in the methanol metabolic pathway that is typically present only in H. polymorpha cells growing on methanol. At least three mutations were introduced in the strains. Two of the mutations resulted in high levels of AOX in glucose-grown cells of the yeast. The third mutation introduced a defect in the cell's normal ability to degrade AOX in response to ethanol, and thus stabilizing the enzyme in the presence of this substrate. Using these strains, conditions for bioconversion of ethanol to acetaldehyde were examined. In addition to pH and buffer concentration, we found that the yield of acetaldehyde was improved by the addition of the proteinase inhibitor phenylmethylsulfonyl fluoride (PMSF) and by permeabilization of the cells with digitonin. Under optimal shake-flask conditions using one of the H. polymorpha mutant strains, conversion of ethanol to acetaldehyde was nearly quantitative.

Single recessive mutations of the methylotrophic yeast Pichia methanolica acs1, acs2, acs3 and icl1 affecting acetyl-CoA synthetase and isocitrate lyase, and growth on ethanol as sole carbon and energy source, caused a defect in autophagic peroxisome degradation during exposure of methanol-grown cells to ethanol. As a control, a mutation in mdd1, which resulted in a defect of the ‘malic’ enzyme and also prevented ethanol utilization, did not prevent peroxisome degradation. Peroxisome degradation in glucose medium was unimpaired in all strains tested. Addition of ethanol to methanol-grown cells of acs1, acs2, acs3 and icl1 mutants led to an increase in average vacuole size. Thickening of peroxisomal membranes and tight contacts between groups of peroxisomes and vacuoles were rarely observed. These processes proceeded much more slowly than in wild-type or mdd1 mutant cells incubated under similar conditions. No peroxisomal remnants were observed inside vacuoles in the cells of acs1, acs2, acs3 and icl1 mutants after prolonged cultivation in ethanol medium. We hypothesize that the acs and icl mutants are defective in synthesis of the true effector—presumably glyoxylate—of peroxisome degradation in ethanol medium. Lack of the effector suspends peroxisome degradation at an early stage, namely signal transduction or peroxisome/vacuole recognition. Finally, these defects in peroxisome degradation resulted in mutant cells retaining high levels of alcohol oxidase which further led to increased levels of acetaldehyde accumulation upon incubation of mutant cells with ethanol. © 1997 by John Wiley & Sons, Ltd.

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.

During the sleep person is in the state of antiorthostasis, this state provokes vascular cerebral abnormalities (night cerebral hypervolemia). The nature of encephalon blood supply is changing in this horizontal state, in the result there is lowering of hydrostatic blood pressure, rise of the encephalon blood supply and more difficult venous outflow. 60 patients with essential hypertension (1-2 phases) at the age of 64.2 +/- 1.8 years which were in the state of slightly raised upper segment of the head and body during night sleep were examined. By the method of the cerebral venous hemocirculation defined. Conclusion. Cerebral arterial blood flow of examined patients has increased by 25-30% during the sleep, the changes of arterial and cerebral venous hemocirculation have attended hypervolemia. Being in the state of upper (by 10-15 degrees) head of the bed decreases blood redistribution and decreases the extension of cerebral blood circulation's acute abnormalities.

An increase of acidophobic thione bacteria quantity in Rozdil and Yavoriv reservoirs of sulfur mining regions during 2005-2009 years, which correlates with a decrease of hydrogen sulfide content in water surface layers, was shown. The ability of acidophobic bacteria of Thiobacillus genus, isolated from "Yavorivske" lake, to oxidize effectively hydrogen sulfide added into Beijerinck medium instead of thiosulfate, was discovered. It was established, that hydrogen sulfide oxidizing efficiency by Thiobacillus sp. Yav-8, Yav-11 and Yav-14 strains is the highest (78.48-84.56%) when its content in cultivation medium was increased twice: to 2584 mg/l. An increase of sulfur quantity in sodium sulfide form from to six times as compared with its standard content in sodium thiosulfate form in the Beijerinck medium does not lead to the increase of hydrogen sulfide oxidizing efficiency by cells.

Eleven pure bacteria cultures, able to oxidize thiosulfate during growth at pH 7.0-9.4, were isolated from surface layers of Yavoriv sulfur deposit open pit waters. Two cultures proved to be obligate aerobes, but nine cultures performed anaerobic respiration using nitrite, N2O (5 cultures) or only nitrite (4 cultures) as terminal electron acceptors. The growth of all cultures at 22 and 28 degrees C and growth absence at 35, 42 and 55 degrees C was established. All the bacteria are obligate chemolithoauthotrophs, because after cultivation with thiosulfate in the presence ofbiotin, yeast extract, formiate, succinate, arabinose, glucose, fructose and sucrose no growth stimulation was observed, heterothropic growth of any culture was not shown. As to their morphology the cells were bacillary, cytoplasmic membrane was surrounded by three-layer cell wall typical of gram negative bacteria intracellular inclusions, nucleoid, ribosomes and polysomes were also available. On the basis of obtained physiological and morphological characteristics the isolated bacteria cultures were referred to a group of neutrophiles, representatives of genus Thiobacillus, in particular to obligate chemolithoauthotrophs.

The influence of some factors (tris-HCl buffer, pH 8.0, concentration, use of different binding agents aeration modes, genetically determined peroxisome degradation damage) on biotransformation efficiency of 0.217 M (1%) ethanol to acetaldehyde at 30 degrees C by Hansenula polymorpha 7-4A (gcrl EAO) strain cells with glucose repression block was investigated. Optimal cultivation conditions for cells were selected. Bioconversion efficiency using 1 M tris-HCl buffer, pH 8.0, was found the highest one as compared with using the buffer in concentrations from 0.1 M to 3 M. The process efficiency when using tris(hydroxymethyl)aminomethane as binding acetaldehyde agent proved much higher than when using sodium bisulfite both at aeration by air stream and incubation on shaker. Using 146 and 179 mutants cells for bioconversion with defects in alcohol oxidase inactivation during macropexophagy stimulated efficiency increase by 5.58% and 8.10%, respectively, as compared with the use of parental 7-4A strain cells.

The article presents the results of studying the peculiarities of the clinical picture, diagnosis and treatment for community-acquired pneumonia in the elderly in view of the interaction of combined pathology of respiratory, cardiovascular and urological systems in order to optimize medical-and-diagnostic support of the above-mentioned category of patients in conditions of the pulmonology department of versatile educational establishment. Optimization of all-round inspection of the sick with pneumonia in the advanced age at an initial stage of treatment in conditions of the pulmonology department so as to reveal the aggravation of internal bodies' combined diseases will allow making early correction of aetiotropic, pathogenetic and symptomatic combined pathology therapy available, which reduces the terms of staying at hospital without damage of diagnosis and treatment.

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.

We report the isolation of mutant strains of the methylotrophic yeast Hansenula polymorpha that are able to efficiently oxidize ethanol to acetaldehyde in an intact cell system. The oxidation reaction is catalyzed by alcohol oxidase (AOX), a key enzyme in the methanol metabolic pathway that is typically present only in H. polymorpha cells growing on methanol. At least three mutations were introduced in the strains. Two of the mutations resulted in high levels of AOX in glucose-grown cells of the yeast. The third mutation introduced a defect in the cell's normal ability to degrade AOX in response to ethanol, and thus stabilizing the enzyme in the presence of this substrate. Using these strains, conditions for bioconversion of ethanol to acetaldehyde were examined. In addition to pH and buffer concentration, we found that the yield of acetaldehyde was improved by the addition of the proteinase inhibitor phenylmethylsulfonyl fluoride (PMSF) and by permeabilization of the cells with digitonin. Under optimal shake-flask conditions using one of the H. polymorpha mutant strains, conversion of ethanol to acetaldehyde was nearly quantitative.

Two types of alcohol-specific microbial/electrochemical biosensors have been developed using specially constructed mutant cells of the methylotrophic yeast Hansenula polymorpha. The cells were immobilized in a calcium alginate gel, and placed between two membranes on the surface of oxygen or hydrogen peroxide-electrodes. The O2 electrode based biosensor contained mutant cells with strongly elevated alcohol oxidase activity. The peroxide electrode based biosensor consisted of catalase-defective mutant cells which produce hydrogen peroxide in the presence of alcohol. Both types of mutant cells were used in permeabilized form in order to release some components of the cellular respiration system, thus increasing the selectivity of the cellular respiration response to alcohol (cell/O2-biosensor) Permeabilization also increased sensitivity of the signal and shortened the response time (cell/H2O2-biosensor). Cell/O2 biosensors were linear up to 1.2 mM for ethanol and 0.35 mM for methanol, cell/H2O2 biosensors were linear up to 4.0 mM for ethanol, and 1.2 mM for methanol. Results were reproducible, sample pretreatment was not required, and the sensors exhibited good operational and storage stability. The use of sucrose, dulcitol or inositol during the preparation of the sensors resulted in increased stability of cells during their liophilization and storage in the dried state. Both biosensors had similar selectivity towards alcohols in the order of methanol (100%), ethanol (21%), and formaldehyde (12%). No signal was observed with glucose or glycerol as substrates.

Single recessive mutations of the methylotrophic yeast Pichia methanolica acs1, acs2, acs3 and icl1 affecting acetyl-CoA synthetase and isocitrate lyase, and growth on ethanol as sole carbon and energy source, caused a defect in autophagic peroxisome degradation during exposure of methanol-grown cells to ethanol. As a control, a mutation in mdd1, which resulted in a defect of the 'malic' enzyme and also prevented ethanol utilization, did not prevent peroxisome degradation. Peroxisome degradation in glucose medium was unimpaired in all strains tested. Addition of ethanol to methanol-grown cells of acs1, acs2, acs3 and icl1 mutants led to an increase in average vacuole size. Thickening of peroxisomal membranes and tight contacts between groups of peroxisomes and vacuoles were rarely observed. These processes proceeded much more slowly than in wild-type or mdd1 mutant cells incubated under similar conditions. No peroxisomal remnants were observed inside vacuoles in the cells of acs1, acs2, acs3 and icl1 mutants after prolonged cultivation in ethanol medium. We hypothesize that the acs and icl mutants are defective in synthesis of the true effector--presumably glyoxylate--of peroxisome degradation in ethanol medium. Lack of the effector suspends peroxisome degradation at an early stage, namely signal transduction or peroxisome/vacuole recognition. Finally, these defects in peroxisome degradation resulted in mutant cells retaining high levels of alcohol oxidase which further led to increased levels of acetaldehyde accumulation upon incubation of mutant cells with ethanol.