Effect of thiosulphate as electron acceptor on glucose and xylose oxidation by Thermoanaerobacter finnii and Thermoanaerobacter sp. isolated from oil field water

#Thermoanaerobacter finnii fermente le glucose et le xylose en lactate, acétate, H2, CO2 et éthanol qui est le produit majeur du métabolisme. Une autre bactérie du genre #Thermoanaerobacter isolée d'une eau de gisement pétrolier produit des quantités aussi importantes d'éthanol que de lactate à partir de ces sucres. L'oxydation du glucose et du xylose par ces deux micro-organismes est complètement modifiée en présence de thiosulfate puisque, dans ces conditions, l'acétate devient le produit majeur du métabolisme des sucres. Cette modification du métabolisme amène à de meilleurs rendements cellulaires et à un meilleur taux de croissance bactérienne lorsque le thiosulfate est utilisé comme accepteur d'électrons. Une plus grande production d'acétate en présence de thiosulfate indique que les bactéries testées récupèrent plus d'énergie des phosphorylations liées au substrat. Ces modifications observées sur le métabolisme des sucres en présence de thiosulfate nous amènent à tenir compte plus précisément du rôle que peut jouer cet accepteur d'électrons dans l'oxydation de la matière organique dans les sources chaudes riches en sulfate sulfuré ou les eaux de gisements pétroliers. (Résumé d'auteur

Large mammal telomere length variation across ecoregions

Background Telomere length provides a physiological proxy for accumulated stress in animals. While there is a growing consensus over how telomere dynamics and their patterns are linked to life history variation and individual experience, knowledge on the impact of exposure to different stressors at a large spatial scale on telomere length is still lacking. How exposure to different stressors at a regional scale interacts with individual differences in life history is also poorly understood. To better understand large-scale regional influences, we investigated telomere length variation in moose (Alces alces) distributed across three ecoregions. We analyzed 153 samples of 106 moose representing moose of both sexes and range of ages to measure relative telomere lengths (RTL) in white blood cells. Results We found that average RTL was significantly shorter in a northern (montane) and southern (sarmatic) ecoregion where moose experience chronic stress related to severe summer and winter temperatures as well as high anthropogenic land-use compared to the boreal region. Our study suggests that animals in the northern boreal forests, with relatively homogenous land use, are less disturbed by environmental and anthropogenic stressors. In contrast, animals in areas experiencing a higher rate of anthropogenic and environmental change experience increased stress. Conclusion Although animals can often adapt to predictable stressors, our data suggest that some environmental conditions, even though predictable and ubiquitous, can generate population level differences of long-term stress. By measuring RTL in moose for the first time, we provide valuable insights towards our current understanding of telomere biology in free-ranging wildlife in human-modified ecosystems

Економічні засади покращення інвестиційного клімату України

Розглянуто тенденцію основних прямих та непрямих інвестицій в країну за певний період та виявлено основну низку системних вад економіко - правового середовища, які заважають припливу іноземних інвестицій. Представлені можливі шляхи покращення інвестиційного клімату України.Considered the main trend of direct and indirect investment in the country for a certain period and found a number of major systemic defects economic and legal environment that hinder foreign investment. Courtesy of the main factors that affect the volume of investment, presents possible ways of improving the investment climate in Ukraine

Isolation and characterization of a new CO-utilizing strain, Thermoanaerobacter thermohydrosulfuricus subsp. carboxydovorans, isolated from a geothermal spring in Turkey

A novel anaerobic, thermophilic, Gram-positive, spore-forming, and sugar-fermenting bacterium (strain TLO) was isolated from a geothermal spring in Ayaş, Turkey. The cells were straight to curved rods, 0.4–0.6 μm in diameter and 3.5–10 μm in length. Spores were terminal and round. The temperature range for growth was 40–80°C, with an optimum at 70°C. The pH optimum was between 6.3 and 6.8. Strain TLO has the capability to ferment a wide variety of mono-, di-, and polysaccharides and proteinaceous substrates, producing mainly lactate, next to acetate, ethanol, alanine, H2, and CO2. Remarkably, the bacterium was able to grow in an atmosphere of up to 25% of CO as sole electron donor. CO oxidation was coupled to H2 and CO2 formation. The G + C content of the genomic DNA was 35.1 mol%. Based on 16S rRNA gene sequence analysis and the DNA–DNA hybridization data, this bacterium is most closely related to Thermoanaerobacter thermohydrosulfuricus and Thermoanaerobacter siderophilus (99% similarity for both). However, strain TLO differs from Thermoanaerobacter thermohydrosulfuricus in important aspects, such as CO-utilization and lipid composition. These differences led us to propose that strain TLO represents a subspecies of Thermoanaerobacter thermohydrosulfuricus, and we therefore name it Thermoanaerobacter thermohydrosulfuricus subsp. carboxydovorans

Genome Analysis of the Anaerobic Thermohalophilic Bacterium Halothermothrix orenii

Halothermothirx orenii is a strictly anaerobic thermohalophilic bacterium isolated from sediment of a Tunisian salt lake. It belongs to the order Halanaerobiales in the phylum Firmicutes. The complete sequence revealed that the genome consists of one circular chromosome of 2578146 bps encoding 2451 predicted genes. This is the first genome sequence of an organism belonging to the Haloanaerobiales. Features of both Gram positive and Gram negative bacteria were identified with the presence of both a sporulating mechanism typical of Firmicutes and a characteristic Gram negative lipopolysaccharide being the most prominent. Protein sequence analyses and metabolic reconstruction reveal a unique combination of strategies for thermophilic and halophilic adaptation. H. orenii can serve as a model organism for the study of the evolution of the Gram negative phenotype as well as the adaptation under thermohalophilic conditions and the development of biotechnological applications under conditions that require high temperatures and high salt concentrations

Is there a common water-activity limit for the three domains of life?

Archaea and Bacteria constitute a majority of life systems on Earth but have long been considered inferior to Eukarya in terms of solute tolerance. Whereas the most halophilic prokaryotes are known for an ability to multiply at saturated NaCl (water activity (a w) 0.755) some xerophilic fungi can germinate, usually at high-sugar concentrations, at values as low as 0.650-0.605 a w. Here, we present evidence that halophilic prokayotes can grow down to water activities of <0.755 for Halanaerobium lacusrosei (0.748), Halobacterium strain 004.1 (0.728), Halobacterium sp. NRC-1 and Halococcus morrhuae (0.717), Haloquadratum walsbyi (0.709), Halococcus salifodinae (0.693), Halobacterium noricense (0.687), Natrinema pallidum (0.681) and haloarchaeal strains GN-2 and GN-5 (0.635 a w). Furthermore, extrapolation of growth curves (prone to giving conservative estimates) indicated theoretical minima down to 0.611 a w for extreme, obligately halophilic Archaea and Bacteria. These were compared with minima for the most solute-tolerant Bacteria in high-sugar (or other non-saline) media (Mycobacterium spp., Tetragenococcus halophilus, Saccharibacter floricola, Staphylococcus aureus and so on) and eukaryotic microbes in saline (Wallemia spp., Basipetospora halophila, Dunaliella spp. and so on) and high-sugar substrates (for example, Xeromyces bisporus, Zygosaccharomyces rouxii, Aspergillus and Eurotium spp.). We also manipulated the balance of chaotropic and kosmotropic stressors for the extreme, xerophilic fungi Aspergillus penicilloides and X. bisporus and, via this approach, their established water-activity limits for mycelial growth (∼0.65) were reduced to 0.640. Furthermore, extrapolations indicated theoretical limits of 0.632 and 0.636 a w for A. penicilloides and X. bisporus, respectively. Collectively, these findings suggest that there is a common water-activity limit that is determined by physicochemical constraints for the three domains of life

Mise en service d'une centrale nucléaire

Les essais de mise en service d'une centrale nucléaire — qui permettent d'éprouver la qualité de la réalisation — constituent une des garanties de disposer d'une installation présentant le maximum de sûreté et de disponibilité. Après avoir présenté les différents types d'essais et leur échelonnement dans le temps, les auteurs indiquent comment ces essais sont préparés, programmés et mis en œuvre. Ils analysent ensuite le contenu théorique du programme des essais établi pour les centrales nucléaires et décrivent son application pratique à la tranche n° 2 de la centrale de Fessenheim