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[en] Full text : The soil polluted by oil and petroleum creates severe social and ecological problem. The solution of indicated problem is requires the development and intrusion of modern progressive technology. Most perspective in this sense can be clearing the oil-polluted soils with usage of activity of microorganisms. The modern level of learning of microorganisms oxidizing oil hydrocarbon testifies to a capability of creation of the non-polluting, economically effective biotechnological schemes. It was established by our researches that in oil polluted soils of Absheron peninsula alongside with hydrocarbon oxidizing bacteria it is finding everywhere lithotrophic bacteria of cycle of sulfur - representatives of sulfate-reducing and bacteria of genus Thiobacillus. It was established that the soil polluted by heavy tarry oil renders negative influencing on development of microorganisms
[en] The content of cellular fatty acids was determined by HRGC of twelve Colombian isolated Pseudomonas aeruginosa 17,18, 19, 20, 21, 22 and 103 pseudomonas sp 23,24,25,26 and 27 with desulphurization capacity, pseudomonas aeruginosa ATCC 9027 and 10145, pseudomonas sp ATCC 39327 and pseudomonas fluorescens. Fifty-three different types of fatty acids were found, among saturated and unsaturated of lineal chain, and mainly hydroxy acids and ramified. Of these, 17 have not been described in the literature for this genus. A group of 6 acids was presented with more frequency (15:0; 16:0; 16:1; 17:1; 3-OH 16:0 and 2-OH 15:0) in more than 75% of the pseudomonas studied. The studied microorganisms are related because they share the presence of some characteristic fatty acids, that which allows assuring that they belong to same taxonomic unit. The analysis cluster developed by means of plotting in dendrograms of the qualitative and quantitative contents of the acids fatty totals showed the formation of two attaches, the I conformed by ATCC 39327 and the isolated 17 and 25, and the II by Ps. Fluorescens and the isolated one 27. The dendrogram of the hydroxy acids shows the formation of four attaches, the I attache, (isolated 17 and 20), the II A (isolated 22 and 103), the II B (isolated 27 and ps. fluorescens) and the attache III (isolated 18 and 19). In that of the ramified fatty acids the formation of a main attache is observed conformed by four sub-groups, the IA (isolated 17), the I B (isolated 18 and 24), the I C (isolated 19 and 25 and Ps. fluorescens) and I D (isolated 27). These results show that the isolated 27,25,24, 19, 18 and 17, in their order, have narrow relationship to Ps. fluorescens
[en] A bioleaching study aimed at recovering metals from hazardous spent hydroprocessing catalysts was carried out. The exhaust catalyst was rich in nickel (4.5 mg/g), vanadium (9.4 mg/g) and molybdenum (4.4 mg/g). Involved microorganisms were iron/sulphur oxidizing bacteria. Investigated factors were elemental sulphur addition, ferrous iron addition and actions contrasting a possible metal toxicity (either adding powdered activated charcoal or simulating a cross current process by means of periodical filtration). Ferrous iron resulted to be essential for metal extraction: nickel and vanadium extraction yields were 83% and 90%, respectively, while about 50% with no iron. The observed values for molybdenum extraction yields were not as high as Ni and V ones (the highest values were around 30-40%). The investigated actions aimed at contrasting a possible metal toxicity resulted not to be effective; in contrast, sequential filtration of the liquor leach had a significant negative effect on metals extraction. Nickel and vanadium dissolution kinetics resulted to be significantly faster than molybdenum dissolution ones. Furthermore, a simple first order kinetic model was successfully fitted to experimental data. All the observed results supported the important role of the indirect mechanism in bioleaching of LC-Finer catalysts.
[en] The susceptibility to the fouling of the NiTi and Ti6Al4V alloys due to the adhesion of microorganisms and the biofilm formation is very significant, especially in the context of an inflammatory state induced by implants contaminated by bacteria, and the implants corrosion stimulated by bacteria. The aim of this work was to examine the differences between the sulphur-oxidizing bacteria (SOB) and sulphate-reducing bacteria (SRB) strains in their affinity for NiTi and Ti6Al4V alloys. The biofilms formed on alloy surfaces by the cells of five bacterial strains (aerobic SOB Acidithiobacillus thiooxidans and Acidithiobacillus ferrooxidans, and anaerobic SRB Desulfovibrio desulfuricans—3 strains) were studied using scanning electron microscopy (SEM) and confocal laser scanning microscopy (CLSM). The protein concentrations in liquid media have also been analyzed. The results indicate that both alloys tested may be colonized by SOB and SRB strains. In the initial stage of the biofilm formation, the higher affinity of SRB to both the alloys has been documented. However, the SOB strains have indicated the higher (although differentiated) adaptability to changing environment as compared with SRB. Stimulation of the SRB growth on the alloys surface was observed during incubation in the liquid culture media supplemented with artificial saliva, especially of lower pH (imitated conditions under the inflammatory state, for example in the periodontitis course). The results point to the possible threat to the human health resulting from the contamination of the titanium implant alloys surface by the SOB (A. thiooxidans and A. ferrooxidans) and SRB (D. desulfuricans). Graphical abstract:
[en] A cementitious surface contaminated with a radioactive substance is decontaminated by applying a micro-organism to the surface to degrade the surface. The residue which contains the radioactive substance is then removed by suction, scraping, brushing or abrasion blasting. The micro-organism might comprise an aerobic sulphur oxidising bacteria, or an anaerobic sulphate reducing bacteria, or a mixture thereof. Action of the micro-organism can be stopped as necessary by heating, or by depriving the micro-organism of nutrients. (author)
[en] PNL is developing a method to use thiophillic microorganisms to devulcanize (biodesulfurize) the surface of ground rubber particles, which will improve the bonding and adhesion of the ground tire rubber into the virgin tire rubber matrix. The Chemi-microbial processing approach, introduced in this paper, is targeted at alleviating the waste tire problem in an environmentally conscious manner; it may also be applied to improve asphaltic materials and rubber and polymeric wastes to facilite their recycling. This paper outlines the logic and technical methods that will be used
[en] The main objective of the ARUM process is to optimize this mineralization in sediments created in mining waste management areas. The most important parameter driving ARUM (or the remineralization process) is the flux of organic carbon from the water column to the microbial communities in the sediment. Various organic materials have been tested as sources of carbon for ARUM in AMD from base metal and coal operations. Carbon availability from materials such as peat, sawdust or Typha leaves depends on decomposition which is extremely limited in acidic, anoxic conditions where ARUM can occur. Weight loss from decomposition bags and sequential nutritional analysis were used to assess decomposition of test organic materials after prolonged exposure (up to two years) in AMD in ponds, lake enclosures (limnocorrals) or constructed ARUM test cells. The results indicate that decomposition can occur in the reducing conditions associated with ARUM and that of all the materials tested, peat is the most promising and sawdust the least promising ARUM substrate
[en] PLFA analysis was conducted to profile microorganisms and trace sulfate-reducing bacteria (SRB) in water samples from an offshore oil reservoir. From the results of spiked phospholipid standards, more than 90% of the phospholipids were recovered before the treatment of fatty acid methyl ester (FAME) derivatization while the relative standard deviations (RSD) were below 8.0%. The water samples from the injection well and four producing wells exhibited various reducing conditions and were further subjected to PLFA analysis. Fourteen kinds of phospholipid fatty acids were detected in the five wellbores and the concentrations of total fatty acids ranged from 368.4 to 3468.9 ng/L. Possible SRB biomarkers and significant phospholipid fatty acids associated with SRB including C14:0, i-C15:0, a-C15:0, C15:0, C16:1 (cis-9), C17:0, C18:1 (cis-9), C18:1 (cis-11) and C18:0 were selected for determining the presence of SRB species and evaluating the sulfate-related microbial biomass. The possible existence of SRB genera Desulfobacter, Desulfotomaculum, Desulfovibrio, and sulfur-oxidizing bacteria (SOB) in the reservoir were proposed based on PLFA profiles. The highest biomass was found in the most reducing well where very limited SOB biomarkers were found. Results indicated that the presence of SRB and SOB species was closely associated with the redox environment of the reservoir wellbores. The species distribution patterns were interpreted to elucidate the biological souring process.
[en] Full text: The principle of the High-Temperature-Superconducting cryogenic current comparator (HTS-CCC), coupled with an HTS SQUID detector, is here applied to the non-invasive sensing of charged-particle beams . When an ion or electron beam is passed along the axis of a superconducting tube, the Meissner effect causes a shielding current to flow in the opposite direction, along the inside surface of the tube. This screening current, which is independent of the trajectory and of the finite width of the beam, returns along the outside surface of the tube, where in principle its magnetic field can be coupled to a detector. The return current is concentrated in a specially-structured HTS thick-film bridge adjacent to a planar gradiometer SQUID. We have experimentally verified both the principle, and the expected sensitivity, of the technique with simple rectangular bridge geometries. We now plan more complex bridge geometries to enhance the sensitivity. For example, if the bridge is S-shaped, we calculate that the beam current resolution for optimum device parameters may be as small as 10 pA/(rtHz). Two thick-film HTS current concentrators designed along these lines are being constructed. As well as providing for continuous non-invasive monitoring of low-intensity beam currents, the above sensitivity together with a typical SQUID response time of ∼1 microsecond should, under appropriate conditions, allow the charged particles, irrespective of their radial distribution, to be individually resolved without interrupting the beam. Applications in ion-beam implantation systems and in mass spectrometry can be envisaged. Recent simulations and experimental measurements of the flux concentration ratio, linearity and sensitivity of such a prototype HTS-CCC operating at 77K are presented
[en] Highlights: • Haloalkaliphilic microorganisms were used to reduce sulfate. • Sulfide concentration reached up to 1603 mg/L. • There was no sulfide inhibition to haloalkaliphilic microorganisms. • Bacterial community of haloalkaliphilic bioreactor was studied. - Abstract: Sulfur dioxide from flue gas was converted into sulfate after the absorption of alkaline solutions. Haloalkaliphilic microorganisms have been used in reducing sulfate to decrease expenses and avoid sulfide inhibition. The effects of different COD/SO42− ratios and hydraulic retention times (HRTs) on the sulfate removal efficiency and bacterial community were investigated in model experiments. Ethanol showed better performance as an electron donor than lactate. The optimum COD/SO42− ratio and HRT were 4.0 and 18 h, respectively, with respective sulfate removal efficiency and rate of 97.8 ± 1.11% and 6.26 ± 0.0710 g/L d. Sulfide concentrations reached 1603 ± 3.38 mg/L. Based on denaturing gradient gel electrophoresis analysis of 16S rDNA, the major sulfate-reducing bacterium (SRB) was Desulfonatronovibrio sp., which was only detected at a COD/SO42− ratio of 4.0 using ethanol as an electron donor. Different HRTs had no significant effect on the band corresponding to this species. PCR results show that methane-producing archaea (MPA) were from the acetoclastic methanogenic family Methanosarcinaceae. Quantitative real-time PCR did not demonstrate any significant competition between SRB and MPA. The findings of this study indicate that sulfate reduction, nitrate reduction, and sulfide oxidization may occur in the same bioreactor