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Каталог книг и продолжающихся изданий библиотеки Института биофизики СО РАН

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Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Varotsos C.A., Franzke C.L.E., Efstathiou M.N., Degermendzhi A.G.
Заглавие : Evidence for two abrupt warming events of SST in the last century
Место публикации : Theoretical and Applied Climatology. - 2013. - С. 1-10. - ISSN 0177798X (ISSN) , DOI 10.1007/s00704-013-0935-8
Аннотация: We have recently suggested that the warming in the sea surface temperature (SST) since 1900, did not occur smoothly and slowly, but with two rapid shifts in 1925/1926 and 1987/1988, which are more obvious over the tropics and the northern midlatitudes. Apart from these shifts, most of the remaining SST variability can be explained by the El Nino Southern Oscillation and the Pacific Decadal Oscillation (PDO). Here, we provide evidence that the timing of these two SST shifts (around 60В years) corresponds well to the quasi-periodicity of many natural cycles, like that of the PDO, the global and Northern Hemisphere annual mean temperature, the Atlantic Multi-decadal Oscillation, the Inter-Tropical Convergence Zone, the Southwest US Drought data, the length of day, the air surface temperature, the Atlantic meridional overturning circulation and the change in the location of the centre of mass of the solar system. In addition, we show that there exists a strong seasonal link between SST and ENSO over the tropics and the NH midlatitudes, which becomes stronger in autumn of the Northern Hemisphere. Finally, we found that before and after each SST shift, the intrinsic properties of the SST time series obey stochastic dynamics, which is unaffected by the modulation of these two shifts. In particular, the SST fluctuations for the time period between the two SST shifts exhibit 1/f-type long-range correlations, which are frequently encountered in a large variety of natural systems. Our results have potential implications for future climate shifts and crossing tipping points due to an interaction of intrinsic climate cycles and anthropogenic greenhouse gas emissions. В© 2013 Springer-Verlag Wien.
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Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Rogozin D.Y., Zykov V.V., Degermendzhi A.G.
Заглавие : Ecology of purple sulfur bacteria in the highly stratified meromictic Lake Shunet (Siberia, Khakassia) in 2002-2009
Место публикации : Microbiology (Russian Federation). - 2012. - Vol. 81, Is. 6. - С. 727-735. - ISSN 00262617 (ISSN) , DOI 10.1134/S0026261712060148
Ключевые слова (''Своб.индексиров.''): bacteriochlorophyll a--chemocline--meromictic lake--purple sulfur bacteria--seasonal dynamics--bacteria (microorganisms)--chromatiaceae
Аннотация: Phototrophic sulfur bacteria form dense accumulations in the chemocline zones of stratified lakes where light reaches the sulfide-containing layers of water. Many works are dedicated to the ecophysiology of these microorganisms in meromictic lakes. However, the role of these microorganisms in the trophic network of these ecosystems, the ways of biomass utilization, and the contribution to the turnover of biogenic elements have so far been insufficiently understood. This work deals with the analysis of many years' seasonal dynamics of the biomass of purple sulfur bacteria and the physicochemical conditions of their environment in Lake Shunet (Siberia, Khakassia, Russia), unraveling the causes of their anomalous development in the chemocline of this lake, as well as the comparative analysis of such type of ecosystems. Lake Shunet is characterized by markedly pronounced stratification and the high density of purple sulfur bacteria (PSB) in the chemocline, which is comparable to that of Lake Mahoney (Canada) where the number of PSB is the greatest among those known in the world. It was shown that, in the period 2002-2009, the total amount of bacterio-chlorophyll a in the water column of Lake Shunet increased and did not correlate with the seasonal variations in temperature and illumination in the chemocline. It was established that PSB cells in the purple layer experienced the effect of self-shading. The sedimentation rate of purple sulfur bacteria in Lake Shunet was low due to the pronounced density gradient in the chemocline zone. Thus, the high number of PSB in the chemocline was due to the combination of strong illumination, a high sulfide concentration, and a high water density gradient, which was responsible for stable stratification and contributed to the accumulation of the cells in a narrow layer. The data obtained could be useful for the paleoreconstruction of climatically deter-mined changes in the level of the lake and its periods of meromixis by the presence of carotenoids and bacte-riochlorophylls in the bottom sediments. В© 2012 Pleiades Publishing, Ltd.
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Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Bartsev S.I., Degermendzhi A.G., Erokhin D.V.
Заглавие : Principle of the worst scenario in the modelling past and future of biosphere dynamics
Место публикации : Ecological Modelling. - 2008. - Vol. 216, Is. 2. - С. 160-171. - ISSN 03043800 (ISSN) , DOI 10.1016/j.ecolmodel.2008.03.002
Ключевые слова (''Своб.индексиров.''): irreversible biosphere changes--minimal model of biosphere--the worst scenario principle--biospherics--agricultural land--anthropogenic effect--atmosphere-biosphere interaction--carbon dioxide--deforestation--little ice age--numerical model--eurasia--europe
Аннотация: The "biosphere-climate" system is subjected to different influences (influx of anthropogenic CO2 and pollutants, deforestation, harmful land management, biological species depopulation, etc.). Therefore, the vital question arises: "Can these influences lead to irreversible negative changes in the climate-biosphere system or a global ecological catastrophe?" The possibility of irreversible changes may be not very high, but one cannot ignore it. So the main aim of our investigation is to evaluate possible consequences of human impact on the biosphere focusing on irreversible changes of it. Traditional mathematical complicated models describe the biosphere in great detail, but the large number of equations and parameters leads to accumulation of uncertainties in the forecast due to inevitable uncertainties of experimental estimations of model parameters. An approach based on the principle of the worst scenario was proposed. Minimization of mathematical model with respect to this principle is conducted to study limiting (but possible) versions of models in which the contribution of the possible compensatory and smoothing mechanisms is minimal. Namely the most unfavorable scenarios (corresponding to the values of parameters at the boundaries of confidence interval) have to be considered in estimating consequences of anthropogenic impact. One of the fastest CO2 releasing mechanisms, based on the positive feedback effect, was considered in the context of the worst scenario principle. The family of simple mathematical models was created for biosphere dynamics representation on different timescales. The main result of the investigation consists in confirmation of the possibility of negative and irreversible changes in the "biosphere-climate" system, caused by amplification of the positive feedback: "anthropogenic emission of CO2 - temperature increase - additional CO2 emission due to decomposition of soil organics". Crucial parameters of models, responsible for avalanche-like biosphere changes, are determined. A realizability of hypotheses on anthropogenic causes of Little Ice Age was estimated by corresponding minimal model. Model were used to show the feasibility of the mechanism describing the changing of agricultural field species into indigenous forests in Europe during the Plague, which led to CO2 decrease and temperature fall. В© 2008 Elsevier B.V. All rights reserved.
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Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Bartsev S.I., Degermendzhi A.G., Erokhin D.V.
Заглавие : Global minimal model of perennial dynamics of carbon in biosphere
Место публикации : Doklady Akademii Nauk. - 2005. - Vol. 401, Is. 2. - С. 233-237. - ISSN 08695652 (ISSN)
Ключевые слова (''Своб.индексиров.''): atmospheric temperature--carbon--climatology--ecology--greenhouse effect--thermal effects--biosphere--carbon perennial dynamics--biology
Аннотация: The suggested model is not intended for describing most probable biosphere dynamics but only for estimating the possibility of catastrophic variant of biosphere dynamics development at antropogenic CO2 emission into atmosphere due to different temperature dependences for key biological biosphere component growth. The main result is demonstration of the possibility of irreversible climate changes and biosphere destruction resulting from interaction of biological processes with greenhouse effect.
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Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Genova S.N., Belolipetskii V.M., Rogozin D.Y., Degermendzhy A.G., Mooij W.M.
Заглавие : A one-dimensional model of vertical stratification of Lake Shira focussed on winter conditions and ice cover
Место публикации : Aquatic Ecology. - 2010. - Vol. 44, Is. 3. - С. 571-584. - ISSN 13862588 (ISSN) , DOI 10.1007/s10452-010-9327-7
Ключевые слова (''Своб.индексиров.''): convective mixed layer--ice formation--ice melting--simplified model--winter profiles--anoxic conditions--hydrogen sulfide--ice cover--inhomogeneity--meromictic lake--numerical model--one-dimensional modeling--pycnocline--salinity--seasonality--stratification--vertical profile--water column--water temperature--khakassia--lake shira--russian federation
Аннотация: In meromictic lakes such as Lake Shira, horizontal inhomogeneity is small in comparison with vertical gradients. To determine the vertical distribution of temperature, salinity, and density of water in a deep zone of a Lake Shira, or other saline lakes, a one-dimensional (in vertical direction) mathematical model is presented. A special feature of this model is that it takes into account the process of ice formation. The model of ice formation is based on the one-phase Stefan problem with the linear temperature distribution in the solid phase. A convective mixed layer is formed under an ice cover due to salt extraction in the ice formation process. To obtain analytical solutions for the vertical distribution of temperature, salinity, and density of water, we use a scheme of vertical structure in the form of several layers. In spring, the ice melts as top and bottom. These processes are taken into account in the model. The calculated profiles of salinity and temperature of Shira Lake are in good agreement with field measurement data for each season. Additionally, we focussed on the redox zone, which is the zone in which the aerobic layers of a water column meet the anaerobic ones. Hyperactivity of plankton communities is observed in this zone in lakes with hydrogen sulphide monimolimnion, and Lake Shira is among them. The location of the redox zone in the lake, which is estimated from field measurements, coincides with a sharp increase in density (the pycnocline) during autumn and winter. During spring and summer, the redox zone is deeper than the pycnocline. The location of pycnocline calculated with the hydro physical model is in good agreement with field measurement data. В© 2010 Springer Science+Business Media B.V.
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Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Prokopkin I.G., Mooij W.M., Janse J.H., Degermendzhy A.G.
Заглавие : A general one-dimensional vertical ecosystem model of Lake Shira (Russia, Khakasia): Description, parametrization and analysis
Место публикации : Aquatic Ecology. - 2010. - Vol. 44, Is. 3. - С. 585-618. - ISSN 13862588 (ISSN) , DOI 10.1007/s10452-010-9326-8
Ключевые слова (''Своб.индексиров.''): meromictic brackish lake--one-dimensional vertical ecological model--sensitivity analysis--alga--biomass--brackish water--diffusion--ecosystem modeling--meromictic lake--microbial community--model test--nutrient--one-dimensional modeling--parameterization--phytoplankton--seasonality--sensitivity analysis--solar radiation--vertical profile--water chemistry--water temperature--zooplankton--khakassia--lake shira--russian federation--algae
Аннотация: A one-dimensional ecological model of the meromictic brackish Lake Shira (Russia, Khakasia) was developed. The model incorporates state-of-the-art knowledge about the functioning of the lake ecosystem using the most recent field observations and ideas from PCLake, a general ecosystem model of shallow freshwater lakes. The model of Lake Shira presented here takes into account the vertical dynamics of biomasses of the main species of algae, zooplankton and microbial community, as well as the dynamics of oxygen, detritus, nutrients and hydrogen sulphide from spring to autumn. Solar radiation, temperature and diffusion are modelled using real meteorological data. The parameters of the model were calibrated to the field data, after applying different methods of sensitivity analysis to the model. The resulting patterns of phytoplankton and nutrients dynamics show a good qualitative and quantitative agreement with the field observations during the whole summer season. Results are less satisfactory with respect to the vertical distribution of zooplankton biomass. We hypothesize that this is due to the fact that the current model does not take the sex and age structure of zooplankton into account. The dynamics of oxygen, hydrogen sulphide and the modelled positions of the chemocline and thermocline are again in good agreement with field data. This resemblance confirms the validity of the approach we took in the model regarding the main physical, chemical and ecological processes. This general model opens the way for checking various hypotheses on the functioning of the Lake Shira ecosystem in future investigations and for analysing options for management of this economically important lake. В© 2010 Springer Science+Business Media B.V.
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Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Rogozin D.Y., Genova S.N., Gulati R.D., Degermendzhy A.G.
Заглавие : Some generalizations based on stratification and vertical mixing in meromictic Lake Shira, Russia, in the period 2002-2009
Место публикации : Aquatic Ecology. - 2010. - Vol. 44, Is. 3. - С. 485-496. - ISSN 13862588 (ISSN) , DOI 10.1007/s10452-010-9328-6
Ключевые слова (''Своб.индексиров.''): 1-d model--meromixis--mixolimnion--oxic-anoxic interface--thermocline--weather conditions--brackish water--meromictic lake--numerical model--one-dimensional modeling--overturn--physicochemical property--salinity--seasonality--stratification--temperate environment--vertical mixing--water temperature--weather--khakassia--lake shira--russian federation
Аннотация: In a brackish, temperate, 24-m-deep Lake Shira, the profiles of salinity, temperature, oxygen and sulfide concentrations were measured on a seasonal basis from 2002 to 2009. The lake was shown to be meromictic with autumnal overturn restricted to mixolimnion. The depth of mixolimnion and position of oxic-anoxic interface varied annually. The spring mixing processes contribute to the formation of mixolimnion in autumn. The exceptionally windy spring of 2007 caused the deepening of mixolimnion in the winter of 2008. The winter position of oxic-anoxic interface was affected by the position of lower boundary of mixolimnion in all winters. The salinity in the winter mixolimnion increased compared with the autumn because of freezing out of salts from the upper water layers meters during ice formation and their dissolution in water below. The profiles of salinity and temperature were simulated by the mathematical 1-D model of temperature and salinity conditions taking into account ice formation. The simulated profiles generally coincided with the measured ones. The coincidence implies that simplified one-dimensional model can be applied to roughly describe salinity and density profiles and mixing behavior of Lake Shira. В© 2010 The Author(s).
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Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Volova T.G., Zhila N.O., Shishatskaya E.I., Mironov P.V., Vasil'Ev A.D., Sukovatyi A.G., Sinskey A.J.
Заглавие : The physicochemical properties of polyhydroxyalkanoates with different chemical structures
Место публикации : Polymer Science - Series A. - 2013. - Vol. 55, Is. 7. - С. 427-437. - ISSN 0965545X (ISSN) , DOI 10.1134/S0965545X13070080
Ключевые слова (''Своб.индексиров.''): amorphous and crystalline phasis--degrees of crystallinity--physicochemical property--poly(3-hydroxybutirate)--polyhydroxyalkanoate copolymer--temperature characteristic--thermal degradation temperatures--thermoplastic materials--copolymers--monomers--thermoplastic elastomers--structure (composition)
Аннотация: A set of polyhydroxyalkanoates are synthesized, and a comparative study of their physicochemical properties is performed. The molecular masses and polydispersities of polyhydroxyalkanoates are found to be independent of their chemical structures. It is shown that the temperature characteristics and degrees of crystallinity of polyhydroxyalkanoates are affected by the chemical compositions of the monomers and their quantitative contents in the polymers. The incorporation of 4-hydroxybutyrate, 3-hydroxyvalerate, and 3-hydroxyhexanoate units into the chain of poly(3-hydroxybutyrate) decreases its melting point and thermal degradation temperature relative to these parameters of a homogeneous poly(3-hydroxybutyrate) sample (175 В± 5 C and 275 В± 5 C, respectively). The higher the content of the second monomer units in the poly(3-hydroxybutirate) chain, the greater the changes. The degrees of crystallinity of polyhydroxyalkanoate copolymers are generally lower than that of poly(3-hydroxybutyrate) (75 В± 5%). The effect on the ratio of the amorphous and crystalline phases of the copolymer samples becomes more pronounced in the series 3-hydroxy-valerate-3-hydroxyhexanoate-4- hydroxybutyrate. The prepared samples exhibit different properties ranging from rigid thermoplastic materials to engineering elastomers. В© 2013 Pleiades Publishing, Ltd.
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Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Voinova O., Gladyshev M., Volova T.G.
Заглавие : Comparative study of PHA degradation in natural reservoirs having various types of ecosystems
Место публикации : Macromolecular Symposia. - 2008. - Vol. 269, Is. 1. - С. 34-37. - ISSN 10221360 (ISSN) , DOI 10.1002/masy.200850906
Ключевые слова (''Своб.индексиров.''): biodegradable polyesters--ecosystem--natural environment--pha--water reservoir--abs resins--biochemistry--biodegradable polymers--biodegradation--biopolymers--biotechnology--degradation--ecology--ecosystems--esters--polymers--aerobic and anaerobic conditions--anaerobic conditions--biodegradable polyesters--comparative studies--ecological characteristics--environment temperatures--natural environment--natural environments--pha--polyhydroxyalkanoate--polymer degradations--water reservoir--water reservoirs--reservoirs (water)
Аннотация: The kinetics of polyhydroxyalkanoate (PHA) degradation in natural environment in two water reservoirs having various ecological characteristics was studied. It was shown that biodegradation of polymer essentially depends on the environment temperature and inorganic composition of water. The processes of polymer degradation under aerobic and anaerobic conditions were compared. The polymer degradation was slower under anaerobic conditions. Copyright В© 2008 WILEY-VCH Verlag GmbH & Co. KGaA.
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10.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Volova T.G., Mironov P.V., Vasil'ev A.D.
Заглавие : Physicochemical properties of multicomponent poly(hydroxyalkanoates)
Место публикации : Biophysics. - 2007. - Vol. 52, Is. 3. - С. 293-297. - ISSN 00063509 (ISSN) , DOI 10.1134/S0006350907030062
Ключевые слова (''Своб.индексиров.''): hydroxyhexanoate--hydroxyvalerate--poly(hydroxybutyrate)--bacteria (microorganisms)--cupriavidus necator--insectivora
Аннотация: The properties of new five-component poly(hydroxyalkanoates) (PHA) formed by short-and medium-chain monomers synthesized by the bacterium Wautersia eutropha B5786 were studied by X-ray diffraction, IR spectroscopy, differential thermal analysis, and viscometry. The degree of crystallinity of PHA decreased from 72 to 57% as the molar fraction of hydroxyhexanoate increased from 2.5 to 18.0 mol%. The melting temperature (T m) and decomposition temperature (T d) of the multicomponent PHA are lower than those for poly(hydroxybutyrate), whose T m and T d are 168-170 and 260-265В°C, respectively. Both parameters of the multicomponent PHA decrease to 156 and 252В°C, respectively, as the hydroxyhexanoate mole fraction is raised. The effect of hydroxyhexanoate on the physicochemical properties of the PHA is similar to that of hydroxyvalerate observed previously. В© 2007 Pleiades Publishing, Inc.
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11.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Shishatskaya E.I., Khlusov I.A., Volova T.G.
Заглавие : A hybrid PHB-hydroxyapatite composite for biomedical application: Production, in vitro and in vivo investigation
Место публикации : Journal of Biomaterials Science, Polymer Edition. - 2006. - Vol. 17, Is. 5. - С. 481-498. - ISSN 09205063 (ISSN) , DOI 10.1163/156856206776986242
Ключевые слова (''Своб.индексиров.''): biocompatibility--hydroxyapatite (ha)--phb-hydroxyapatite composite--polyhydroxyalkanoate (pha)--polyhydroxybutyrate (p(3hb))--properties--biocompatibility--differential thermal analysis--electron microscopy--free energy--interfacial energy--physical properties--surface properties--x ray analysis--biomedical application--physicochemical properties--polyhydroxyalkanoate (pha)--polyhydroxybutyrate (phb)--hydroxyapatite--hydroxyapatite--poly(3 hydroxybutyric acid)--polymer--biomaterial--hydroxybutyric acid--adhesion--animal cell--animal tissue--article--biomedicine--bone marrow cell--cell differentiation--cell growth--chemical structure--composite material--controlled study--crystallization--decomposition--electron microscopy--in vitro study--in vivo study--melting point--mouse--nonhuman--ossification--osteoblast--physical chemistry--priority journal--rat--strength--structure analysis--surface property--synthesis--temperature measurement--thermal analysis--tissue engineering--wettability--animal--biomechanics--bioremediation--bone prosthesis--cattle--cell culture--chemistry--cytology--differential scanning calorimetry--drug effect--human--materials testing--prostheses and orthoses--scanning electron microscopy--standard--wistar rat--murinae--animals--biocompatible materials--biodegradation, environmental--biomechanics--bone substitutes--cattle--cells, cultured--differential thermal analysis--durapatite--humans--hydroxybutyrates--materials testing--microscopy, electron, scanning--osteoblasts--prostheses and implants--rats--rats, wistar--surface properties
Аннотация: Samples of a hybrid composite of polyhydroxybutyrate (PHB), a biodegradable polyester, and hydroxyapatite (HA), with different PHB/HA ratios, have been prepared using mechanical-physical method. Electron microscopy, X-ray structure analysis and differential thermal analysis have been used to investigate the structure and physicochemical properties of the composite, depending on the PHB/HA ratio. The properties of the surface of the HA-loaded composite are significantly different from those of the pure polymer. As the HA percentage in the composite increases, free interface energy, the cohesive force, i.e., the strength of the adhesive bond between the composite surface and the water phase, and surface wettability increase. The HA percentage of the composite does not influence its melting temperature, but affects the temperature for the onset of decomposition: as the HA content increases from 0 to 10% (w/w), Td decreases from 260В°C to 225В°C. The degree of crystallinity of PHB/HA increases from 77% to 89% with an increase in the HA fraction from 10% to 50%. Functional properties of the composites have been investigated in vitro and in vivo. The best parameters of growth and differentiation of murine marrow osteoblasts are registered on PHB/HA samples containing 10% and 20% HA. In ectopic bone formation assay it has been proven that the hybrid PHB/HA composites can function as scaffolds and that bone tissue develops on their surface and in pores. В© VSP 2006.
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12.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Volova T.G., Plotnikov V.F., Shishatskaya E.I., Mironov P.V., Vasil'ev A.D.
Заглавие : Physicochemical properties of two-component polyhydroxyalkanoates, 3-hydroxybutyrate-3-hydroxyvalerate copolymers
Место публикации : Biophysics. - 2004. - Vol. 49, Is. 6. - С. 934-942. - ISSN 00063509 (ISSN)
Ключевые слова (''Своб.индексиров.''): hydroxybutyrate-hydroxyvalerate copolymers--physicochemical properties--polyhydroxyalkanoates--structure--bacteria (microorganisms)--cupriavidus necator
Аннотация: A series of two-component polyhydroxyalkanoates composed of hydroxybutyrate-hydroxyvalerate copolymers with different monomer ratio was obtained with the use of bacteria Ralstonia eutropha B5786. The properties of the polyhydroxyalkanoates in comparison with the homopolymer of hydroxybutyric acid were studied by X-ray diffraction analysis, IR spectroscopy, differential thermal analysis, and viscometry. The ratio of crystalline to amorphous phase in the copolymers tends to unity with increasing hydroxyvalerate content. This is accompanied by a decrease in the degree of crystallinity of the copolymers from 70-80 to 45-50%, the dependence is virtually linear within the range, of hydroxyvalerate mole fraction from several to 25-30 mol%. Thermal characteristics, melting temperature (Tm) and decomposition temperature (Td), of the polyhydroxyalkanoate copolymers are lower than those for polyhydroxybutyrate, whose Tm and Td are 168-170 and 260-265В°C, respectively. Both parameters decrease to 150-160 and 200-220В°C, respectively, when the hydroxyvalerate mole fraction is raised. No distinct correlation between polymer composition and molecular weight has been revealed. Copyright В© 2004 by MAIK "Nauka/Interperiodica".
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13.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Sushchik N.N., Kalacheva G.S., Zhila N.O., Gladyshev M.I., Volova T.G.
Заглавие : A Temperature Dependence of the Intra- and Extracellular Fatty-Acid Composition of Green Algae and Cyanobacterium
Место публикации : Russian Journal of Plant Physiology. - 2003. - Vol. 50, Is. 3. - С. 374-380. - ISSN 10214437 (ISSN) , DOI 10.1023/A:1023830405898
Ключевые слова (''Своб.индексиров.''): cyanobacterium--fatty acids--green algae--lipids--secretion--algae--bacteria (microorganisms)--botryococcus braunii--chlorella vulgaris--chlorophyta--eukaryota--prokaryota--spirulina--spirulina platensis
Аннотация: The effect of ambient temperature on the composition of intracellular fatty acids and the release of free fatty acids (FFA) into a medium by cyanobacterium Spirulina platensis and eukaryotic microalgae, Chlorella vulgaris and Botryococcus braunii, was studied using their batch cultures. It was found that all the species studied, regardless of their taxonomic status, responded to the temperature regime by similar changes in their intracellular fatty acid composition: the relative content of more unsaturated fatty acids decreased with the elevation of temperature. At the same time, in the prokaryote, this temperature shift blocked, first of all, the elongation of 16: 0 to 18:0 and then their further desaturation. In eukaryotes, the change in the desaturation of dienoic to trienoic fatty acids was the most pronounced process. The ratio of dienoic to trienoic fatty acids remained almost unchanged in S. platensis. The relative content of extracellular unsaturated FFA increased in the prokaryotic organism S. platensis at a higher temperature. But no significant changes in the composition of extracellular unsaturated FFA were detected in eukaryotic algae upon temperature elevation.
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14.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Volova T.G., Voinov N.A.
Заглавие : Kinetic Parameters of a Culture of the Hydrogen-Oxidizing Bacterium Ralstonia eutropha Grown under Conditions Favoring Polyhydroxybutyrate Biosynthesis
Место публикации : Applied Biochemistry and Microbiology. - 2003. - Vol. 39, Is. 2. - С. 166-170. - ISSN 00036838 (ISSN) , DOI 10.1023/A:1022585912873
Ключевые слова (''Своб.индексиров.''): hydrogen--poly(3 hydroxybutyric acid)--article--bacterial growth--bacterium culture--biosynthesis--controlled study--culture medium--density--fermentation--gas--gravimetry--heat exchange--nonhuman--oxidation--ralstonia eutropha--surface tension--temperature dependence--thermogenesis--bacteria (microorganisms)--ralstonia--wautersia eutropha
Аннотация: Kinetic parameters of a culture of the hydrogen-oxidizing bacterium Ralstonia eutropha grown on a gas substrate under conditions favoring autotrophic biosynthesis of polyhydroxybutyrate were studied. The following parameters, making it possible to control and optimize the process in industrial situations, were determined: specific rate of substrate consumption, physical properties of the culture medium, and coefficients of heat emission and mass transfer.
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15.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Volova T.G., Voinov N.A.
Заглавие : Kinetic parameters of a culture of the hydrogen-oxidizing Ralstonia eutropha, grown under the regimen of biosynthesis of polyhydroxybutyrate
Место публикации : Prikladnaia biokhimiia i mikrobiologiia. - 2003. - Vol. 39, Is. 2. - С. 189-193. - ISSN 05551099 (ISSN)
Ключевые слова (''Своб.индексиров.''): hydrogen--hydroxybutyric acid--polyester--article--culture medium--enzyme specificity--growth, development and aging--kinetics--metabolism--oxidation reduction reaction--temperature--wautersia eutropha--culture media--cupriavidus necator--hydrogen--hydroxybutyrates--kinetics--oxidation-reduction--polyesters--substrate specificity--temperature
Аннотация: Kinetic parameters of a culture of the hydrogen-oxidizing bacterium Ralstonia eutropha, grown on a gas substrate under the conditions favoring autotrophic biosynthesis of polyhydroxybutyrate, were studied. The following parameters, making it possible to control and optimize the process in industrial situations, were determined: specific rate of substrate consumption, physical properties of culture medium, and coefficients of heat emission and mass transfer.
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16.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Kalacheva G.S., Zhila N.O., Volova T.G., Gladyshev M.I.
Заглавие : The effect of temperature on the lipid composition of the green alga Botryococcus
Место публикации : Microbiology. - 2002. - Vol. 71, Is. 3. - С. 286-293. - ISSN 00262617 (ISSN) , DOI 10.1023/A:1015898426573
Ключевые слова (''Своб.индексиров.''): fatty acids--green alga--lipids--temperature--algae--botryococcus--chlorophyta
Аннотация: The lipid composition of the green alga Botryococcus was studied at three different cultivation temperatures: suboptimal (18В°C), optimal (25В°C), and supraoptimal (32В°C). Cultivation at the supraoptimal temperature was found to considerably inhibit the synthesis of nearly all intracellular lipids, except for triacylglycerides, and to influence their fatty acid composition. In particular, the content of trienoic fatty acids was significantly lower at the supraoptimal than at the optimal cultivation temperature. At the same time, the fatty acid composition of the extracellular lipids of the alga virtually did not depend on cultivation temperature. В© 2002 MAIK "Nauka/ Interperiodica".
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17.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Kalacheva G.S., Zhila N.O., Volova T.G., Gladyshev M.I.
Заглавие : The effect of temperature on the lipid composition of Botryococcus
Место публикации : Mikrobiologiya. - 2002. - Vol. 71, Is. 3. - С. 336-344. - ISSN 00263656 (ISSN)
Ключевые слова (''Своб.индексиров.''): fatty acid--lipid--triacylglycerol--article--biosynthesis--chemistry--comparative study--green alga--growth, development and aging--metabolism--temperature--algae, green--fatty acids--lipids--temperature--triglycerides
Аннотация: The lipid composition of the green alga Botryococcus was studied at three different cultivation temperatures: suboptimal, optimal, and supraoptimal. Cultivation at the supraoptimal temperature was found to considerably inhibit the synthesis of nearly all intracellular lipids, except for triacylglycerides, and to influence their fatty acid composition. In particular, the content of trienoic fatty acids was significantly lower at the supraoptimal than at the optimal cultivation temperature. At the same time, the fatty acid composition of the extracellular lipids of the alga virtually did not depend on cultivation temperature.
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18.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Volova T.G., Kalacheva G.S., Altukhova O.V.
Заглавие : Autotrophic synthesis of polyhydroxyalkanoates by the bacteria Ralstonia eutropha in the presence of carbon monoxide
Место публикации : Applied Microbiology and Biotechnology. - 2002. - Vol. 58, Is. 5. - С. 675-678. - ISSN 01757598 (ISSN) , DOI 10.1007/s00253-002-0941-8
Ключевые слова (''Своб.индексиров.''): 3 hydroxybutyric acid--acetoacetyl coenzyme a reductase--acetyl coenzyme a acyltransferase--beta hydroxyvalerate--butyrate dehydrogenase--carbon monoxide--electrolyte--hydrogen--oxidoreductase--poly(3 hydroxybutyric acid)--poly(3 hydroxybutyric acid)synthase--polyhydroxyalkanoic acid--polymer--unclassified drug--valeric acid--bacterium--article--autotrophy--bacterial growth--bacterial strain--biomass production--controlled study--crystallization--enzyme activity--molecular weight--nonhuman--synthesis--temperature--wautersia eutropha--carbon monoxide--culture media--cupriavidus necator--fatty acids--lipids--polyesters--bacteria (microorganisms)--negibacteria--ralstonia--wautersia eutropha
Аннотация: It has been found that the carbon monoxide (CO)-resistant strain of the hydrogen bacteria Ralstonia eutropha B5786 is able to synthesise polyhydroxy-alkanoates (PHAs) in the presence of CO under autotrophic conditions. This strain, grown on model gas mixtures containing 5-25% CO (v/v), accumulates up to 70-75% (of absolutely dry matter) PHA, without significant variation in the yield coefficient on hydrogen. No suppression of the activities of the key enzymes of PHA synthesis (?-ketothiolase, acetoacetyl-CoA-reductase, butyrate dehydrogenase and poly-3-hydroxybutyrate synthase) was recorded. The PHA synthesised is a copolymer containing mostly ?-hydroxybutyrate (more than 99 mol%) with trace amounts of ?-hydroxyvalerate. The investigated properties of the polymer (molecular weight, crystallinity, temperature characteristics) do not differ from those of the polymer synthesised on electrolytic hydrogen.
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19.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Beliaev G.A., Volova T.G., Drokin N.A., Shepov V.N.
Заглавие : Study of the dielectric permeability in the superhigh frequency range of a degraded polyoxybutyrate biopolymer
Место публикации : Biofizika. - 2000. - Vol. 45, Is. 4. - С. 636-640. - ISSN 00063029 (ISSN)
Ключевые слова (''Своб.индексиров.''): biopolymer--hydroxybutyric acid--alcaligenes--article--chemistry--electric conductivity--radiofrequency radiation--alcaligenes--biopolymers--electric conductivity--hydroxybutyrates--radio waves
Аннотация: The dielectric permeability of the degradable biopolymer polyhydroxybutyrate synthesized by hydrogen-oxidizing bacteria Alcaligenes eutrophus was investigated by the resonance method using original highly sensitive microstrip sensors. For the first time, a linear growth of dielectric permeability (delta epsilon/delta T = 7 x 10(-4) degree-1) due to the flexibility of the polymer chain in the temperature range from 10 to 70 degrees C was revealed. The energy of a bend of the nearest fragments was evaluated (E = 392 K), and its correspondence to the energies of bends of the alcyl groups of low-molecular substances like liquid crystals was established. It was shown that at low values of dielectric permeability in the high-frequency range (epsilon' = 2.25 +/- 0.02), which are stable, in a wide range of frequencies of the electromagnetic field (1 MHz - 1 Hz), polyoxybutyrate can be used in the microwave equipment.
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20.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Belyaev B.A., Volova T.G., Drokin N.A., Shepov V.N.
Заглавие : The SHF dielectric permeability of polyhydroxybutyrate, a degradable biological polymer.
Место публикации : Doklady Biophysics. - 2000. - Vol. 370-372. - С. 9-12. - ISSN 00124974 (ISSN)
Ключевые слова (''Своб.индексиров.''): hydroxybutyric acid--polymer--article--chemistry--electricity--electromagnetic field--temperature--electromagnetic fields--electrostatics--hydroxybutyrates--polymers--temperature
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