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Mobilization of sulfur by green sulfur bacteria : physiological and molecular studies on Chlorobaculum parvum DSM 263  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Green sulfur bacteria are photolithotrophs that use inorganic sulfur compounds as electron donors for photosynthesis. Elemental, solid sulfur is one of the electron donors used. Sulfur is produced by green sulfur bacteria during the oxidation of sulfide to sulfate, and during the oxidation of thiosu...

Donà, Clelia

2

Novel green sulfur bacteria phylotypes detected in saline environments: ecophysiological characters versus phylogenetic taxonomy.  

UK PubMed Central (United Kingdom)

The taxonomic significance of salt tolerance or requirements in green sulfur bacteria has been analyzed with environmental populations and enrichment cultures from several saline systems (inland and coastal water bodies) with different salinities (salt composition and concentration). Novel phylotypes of green sulfur bacteria have been found in hypersaline and brackish environments and 16S rRNA gene sequence analysis affiliated them into phylogenetic groups in which neither halotolerant nor halophilic species have been known to date. Therefore, salt tolerance does not seem to be restricted to members of any specific subgroup but is widespread among all the different phylogenetic branches of the green sulfur bacteria group, and closely-related phylotypes can have dissimilar salt tolerance capacities. Thus the phenotypic characteristics and phylogenetic structure of the green sulfur bacteria present some incongruities. Phenotypic traits should be studied further in order to determine the ecophysiological features of green sulfur bacteria phylotypes.

Triadó-Margarit X; Vila X; Abella CA

2010-05-01

3

Sulfur globule oxidation in green sulfur bacteria is dependent on the dissimilatory sulfite reductase system  

DEFF Research Database (Denmark)

Green sulfur bacteria oxidize sulfide and thiosulfate to sulfate with extracellular globules of elemental sulfur as intermediate. Here we investigated which genes are involved in the formation and consumption of these sulfur globules in the green sulfur bacterium Chlorobaculum tepidum. We show that sulfur globule oxidation is strictly dependent on the dissimilatory sulfite reductase (DSR) system. Deletion of dsrM/CT2244 or dsrT/CT2245 or the two dsrCABL clusters (CT0851-CT0854, CT2247-2250) abolished sulfur globule oxidation and prevented formation of sulfate from sulfide, whereas deletion of dsrU/CT2246 had no effect. The DSR system also seems to be involved in formation of thiosulfate, because thiosulfate is released from wild type cells during sulfide oxidation, but not from the dsr mutants. The dsr mutants incapable of complete substrate oxidation oxidized sulfide and thiosulfate about twice as fast as the wild type, while having only slightly lower growth rates (70-80% of wild type). The increased oxidation rates seem to compensate for the incomplete substrate oxidation to satisfy the requirement for reducing equivalents during growth. A mutant in which two sulfide:quinone oxidoreductases (sqrB/CT0117 and sqrD/CT1087) were deleted, exhibited a decreased sulfide oxidation rate (~50% of wild type), yet formation and consumption of sulfur globules were not affected. The observation that mutants lacking the DSR system maintain efficient growth, suggests that the DSR system is dispensable in environments with sufficient sulfide concentrations. Thus, the DSR system in GSB may have been acquired by horizontal gene transfer in a response to a need for improved substrate utilization in sulfide-limiting habitats.

Holkenbrink, Carina; Ocón Barbas, Santiago

2011-01-01

4

Mechanisms and evolution of oxidative sulfur metabolism in green sulfur bacteria  

DEFF Research Database (Denmark)

Green sulfur bacteria (GSB) constitute a closely related group of photoautotrophic and thiotrophic bacteria with limited phenotypic variation. They typically oxidize sulfide and thiosulfate to sulfate with sulfur globules as an intermediate. Based on genome sequence information from 15 strains, the distribution and phylogeny of enzymes involved in their oxidative sulfur metabolism was investigated. At least one homolog of sulfide:quinone oxidoreductase (SQR) is present in all strains. In all sulfur-oxidizing GSB strains except the earliest diverging Chloroherpeton thalassium, the sulfide oxidation product is further oxidized to sulfite by the dissimilatory sulfite reductase (DSR) system. This system consists of components horizontally acquired partly from sulfide-oxidizing and partly from sulfate-reducing bacteria. Depending on the strain, the sulfite is probably oxidized to sulfate by one of two different mechanisms that have different evolutionary origins: adenosine-5'-phosphosulfate reductase or polysulfide reductase-like complex 3. Thiosulfate utilization by the SOX system in GSB has apparently been acquired horizontally from Proteobacteria. SoxCD does not occur in GSB, and its function in sulfate formation in other bacteria has been replaced by the DSR system in GSB. Sequence analyses suggested that the conserved soxJXYZAKBW gene cluster was horizontally acquired by Chlorobium phaeovibrioides DSM 265 from the Chlorobaculum lineage and that this acquisition was mediated by a mobile genetic element. Thus, the last common ancestor of currently known GSB was probably photoautotrophic, hydrogenotrophic, and contained SQR but not DSR or SOX. In addition, the predominance of the Chlorobium-Chlorobaculum-Prosthecochloris lineage among cultured GSB could be due to the horizontally acquired DSR and SOX systems. Finally, based upon structural, biochemical, and phylogenetic analyses, a uniform nomenclature is suggested for sqr genes in prokaryotes.

Gregersen, Lea Haarup; Bryant, Donald A.

2011-01-01

5

Atomistic study of energy funneling in the light-harvesting complex of green sulfur bacteria  

CERN Multimedia

Phototrophic organisms such as plants, photosynthetic bacteria and algae use microscopic complexes of pigment molecules to absorb sunlight. Within the light-harvesting complexes, which frequently have multiple functional and structural subunits, the energy is transferred in the form of molecular excitations with very high efficiency. Green sulfur bacteria are considered to be amongst the most efficient light-harvesting organisms. Despite multiple experimental and theoretical studies of these bacteria the physical origin of the efficient and robust energy transfer in their light-harvesting complexes is not well understood. To study excitation dynamics at the systems level we introduce an atomistic model that mimic a complete light-harvesting apparatus of green sulfur bacteria. The model contains about 4000 pigment molecules and comprises a double wall roll for the chlorosome, a baseplate and six Fenna-Matthews-Olson trimer complexes. We show that the fast relaxation within functional subunits combined with the...

Huh, Joonsuk; Brookes, Jennifer C; Valleau, Stéphanie; Fujita, Takatoshi; Aspuru-Guzik, Alán

2013-01-01

6

Low-Temperature Fluorescence from Single Chlorosomes, Photosynthetic Antenna Complexes of Green Filamentous and Sulfur Bacteria  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Fluorescence spectra of single chlorosomes isolated from a green filamentous bacterium (Chloroflexus (Cfl.) aurantiacus) and a green sulfur bacterium (Chlorobium (Cb.) tepidum) were measured by using a confocal laser microscope at 13 K. Chlorosomes were frozen either in a liquid solution (floating c...

Shibata, Yutaka; Saga, Yoshitaka; Tamiaki, Hitoshi; Itoh, Shigeru

7

Exciton description of chlorosome to baseplate excitation energy transfer in filamentous anoxygenic phototrophs and green sulfur bacteria.  

UK PubMed Central (United Kingdom)

A description of intra-chlorosome and from chlorosome to baseplate excitation energy transfer in green sulfur bacteria and in filamentous anoxygenic phototrophs is presented. Various shapes and sizes, single and multiwalled tubes, cylindrical spirals and lamellae of the antenna elements mimicking pigment organization in chlorosomes were generated by using molecular mechanics calculations, and the absorption, LD, and CD spectra of these were predicted by using exciton theory. Calculated absorption and LD spectra were similar for all modeled antenna structures; on the contrary, CD spectra turned out to be sensitive to the size and pigment orientations in the antenna. It was observed that, bringing two tubular antennae at close enough interaction distance, the exciton density of the lowest energy state became localized on pigments facing each other in the antenna dimer. Calculations predicted for stacked tubular antenna elements extremely fast, faster than 500 fs, intra-chlorosome energy transfer toward the baseplates in the direction perpendicular to the chlorosome long axis. Downhill excitation energy transfer according to our model is driven by interactions of the antennae with their immediate surroundings. Energy transfer from the chlorosome to the baseplate, consisting of 2D lattices of monomeric and dimeric bacteriochlorophyll a molecules, was predicted to occur in 5-15 ps, in agreement with experimental findings. Advancement of excitation through a double tube antenna stack, a model for antenna element organization in chlorosomes of green sulfur bacteria, to a monomeric baseplate was visualized in space and in time.

Linnanto JM; Korppi-Tommola JE

2013-09-01

8

Low-temperature fluorescence from single chlorosomes, photosynthetic antenna complexes of green filamentous and sulfur bacteria.  

UK PubMed Central (United Kingdom)

Fluorescence spectra of single chlorosomes isolated from a green filamentous bacterium (Chloroflexus (Cfl.) aurantiacus) and a green sulfur bacterium (Chlorobium (Cb.) tepidum) were measured by using a confocal laser microscope at 13 K. Chlorosomes were frozen either in a liquid solution (floating chlorosome) or on a quartz plate after being adsorbed (adsorbed chlorosome). Fluorescence peak wavelengths were shorter for the adsorbed single chlorosomes than for the floating ones. Single floating Cfl. chlorosomes showed a distribution of fluorescence peak positions having a center at 759.0 nm with a full width at half maximum of 6.3 nm. Single floating Cb. chlorosomes showed a 782.7 nm center with a full width at half-maximum of 3.4 nm. The distribution shifted to the blue and became wider with increasing temperature, especially in Cb. chlorosomes, suggesting a large excitonic density of states just above the lowest level. Energy transfer from BChl-c aggregates to BChl-a molecules in the baseplate proteins was observed in the floating chlorosomes but not in the adsorbed ones. A positive correlation was found between the peak wavelength of BChl-c fluorescence and the intensity of BChl-a fluorescence in single Cfl. chlorosomes. The results suggest that the BChl-c aggregates with longer wavelengths of the fluorescence peaks have a more efficient Förster-type energy transfer to the baseplate BChl-a.

Shibata Y; Saga Y; Tamiaki H; Itoh S

2006-11-01

9

Dominance of green sulfur bacteria in the chemocline of the meromictic Lake Suigetsu, Japan, as revealed by dissimilatory sulfite reductase gene analysis.  

UK PubMed Central (United Kingdom)

This study investigated the spatiotemporal abundance and diversity of the ?-subunit of the dissimilatory sulfite reductase gene (dsrA) in the meromictic Lake Suigetsu for assessing the sulfur-oxidizing bacterial community. The density of dsrA in the chemocline reached up to 3.1 × 10(6) copies ml(-1) in summer by means of quantitative real-time PCR and it was generally higher than deeper layers. Most of the dsrA clones sequenced were related to green sulfur bacteria such as Chlorobium phaeovibrioides, C. limicola, and C. luteolum. Below the chemocline of the lake, we also detected other dsrA clones related to the purple sulfur bacterium Halochromatium salexigens and some branching lineages of diverse sequences that were related to chemotrophic sulfur bacterial species such as Magnetospirillum gryphiswaldense, Candidatus Ruthia magnifica, and Candidatus Thiobios zoothamnicoli. The abundance and community compositions of sulfur-oxidizing bacteria changed depending on the water depth and season. This study indicated that the green sulfur bacteria dominated among sulfur-oxidizing bacterial population in the chemocline of Lake Suigetsu and that certain abiotic environmental variables were important factors that determined sulfur bacterial abundance and community structure.

Mori Y; Kataoka T; Okamura T; Kondo R

2013-05-01

10

Temperature and Carbon Assimilation Regulate the Chlorosome Biogenesis in Green Sulfur Bacteria  

CERN Multimedia

Green photosynthetic bacteria adjust the structure and functionality of the chlorosome - the light absorbing antenna complex - in response to environmental stress factors. The chlorosome is a natural self-assembled aggregate of bacteriochlorophyll (BChl) molecules. In this study we report the regulation of the biogenesis of the Chlorobaculum tepidum chlorosome by carbon assimilation in conjunction with temperature changes. Our studies indicate that the carbon source and thermal stress culture of Cba. tepidum grows slower and incorporates less BChl c in the chlorosome. Compared with the chlorosome from other cultural conditions we investigated, the chlorosome from the carbon source and thermal stress culture displays: (a) smaller cross-sectional radius and overall size; (b) simplified BChl c homologues with smaller side chains; (c) blue-shifted Qy absorption maxima and (d) a sigmoid-shaped circular dichroism (CD) spectra. Using a theoretical model we analyze how the observed spectral modifications can be assoc...

Tang, Joseph Kuo-Hsiang; Pingali, Sai Venkatesh; Enriquez, Miriam M; Huh, Joonsuk; Frank, Harry A; Urban, Volker S; Aspuru-Guzik, Alan

2013-01-01

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Utilization of 'elemental' sulfur by different phototrophic sulfur bacteria (Chromatiaceae, Ectothiorhodospiraceae): A sulfur K-edge XANES spectroscopy study  

International Nuclear Information System (INIS)

[en] Phototrophic sulfur bacteria are generally able to use elemental sulfur as an electron donor for anoxygenic photosynthesis. Elemental sulfur is mainly a mixture of cyclo-octasulfur and polymeric sulfur. The purple sulfur bacterium Allochromatium vinosum strongly prefers the polymeric sulfur fraction showing that sulfur speciation has a strong influence on availability of elemental sulfur. X-ray absorption near edge structure (XANES) spectroscopy was used to investigate whether polymeric sulfur is also the preferred sulfur species in other purple sulfur bacteria belonging to the families Chromatiaceae and Ecothiorodospiraceae. The cultures were fed with 50 mM of elemental sulfur consisting of 68% polymeric sulfur and 30% cyclo-octasulfur. In all cultures, elemental sulfur was converted into intra- or extracellular sulfur globules, respectively, and further oxidized to sulfate. Sulfate concentrations were determined by HPLC and turbidometric assays, respectively. However, the added elemental sulfur was only partly used by the bacteria, one part of the 'elemental sulfur' remained in the cultures and was not taken up. XANES spectroscopy revealed that only the polymeric sulfur fraction was taken up by all cultures investigated. This strongly indicates that polymeric 'chain-like' sulfur is the form preferably used by phototrophic sulfur bacteria.

2009-01-01

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Sulfur bacteria in wastewater stabilization ponds periodically affected by the 'red-water' phenomenon.  

UK PubMed Central (United Kingdom)

Several wastewater stabilization ponds (WSP) in Tunisia suffer periodically from the 'red-water' phenomenon due to blooming of purple sulfur bacteria, indicating that sulfur cycle is one of the main element cycles in these ponds. In this study, we investigated the microbial diversity of the El Menzeh WSP and focused in particular on the different functional groups of sulfur bacteria. For this purpose, we used denaturing gradient gel electrophoresis of PCR-amplified fragments of the 16S rRNA gene and of different functional genes involved in microbial sulfur metabolism (dsrB, aprA, and pufM). Analyses of the 16S rRNA revealed a relatively high microbial diversity where Proteobacteria, Chlorobi, Bacteroidetes, and Cyanobacteria constitute the major bacterial groups. The dsrB and aprA gene analysis revealed the presence of deltaproteobacterial sulfate-reducing bacteria (i.e., Desulfobacter and Desulfobulbus), while the analysis of 16S rRNA, aprA, and pufM genes assigned the sulfur-oxidizing bacteria community to the photosynthetic representatives belonging to the Chlorobi (green sulfur bacteria) and the Proteobacteria (purple sulfur and non sulfur bacteria) phyla. These results point on the diversity of the metabolic processes within this wastewater plant and/or the availability of sulfate and diverse electron donors.

Belila A; Abbas B; Fazaa I; Saidi N; Snoussi M; Hassen A; Muyzer G

2013-01-01

13

Disproportionation of elemental sulfur by haloalkaliphilic bacteria from soda lakes.  

UK PubMed Central (United Kingdom)

Microbial disproportionation of elemental sulfur to sulfide and sulfate is a poorly characterized part of the anoxic sulfur cycle. So far, only a few bacterial strains have been described that can couple this reaction to cell growth. Continuous removal of the produced sulfide, for instance by oxidation and/or precipitation with metal ions such as iron, is essential to keep the reaction exergonic. Hitherto, the process has exclusively been reported for neutrophilic anaerobic bacteria. Here, we report for the first time disproportionation of elemental sulfur by three pure cultures of haloalkaliphilic bacteria isolated from soda lakes: the Deltaproteobacteria Desulfurivibrio alkaliphilus and Desulfurivibrio sp. AMeS2, and a member of the Clostridia, Dethiobacter alkaliphilus. All cultures grew in saline media at pH 10 by sulfur disproportionation in the absence of metals as sulfide scavengers. Our data indicate that polysulfides are the dominant sulfur species under highly alkaline conditions and that they might be disproportionated. Furthermore, we report the first organism (Dt. alkaliphilus) from the class Clostridia that is able to grow by sulfur disproportionation.

Poser A; Lohmayer R; Vogt C; Knoeller K; Planer-Friedrich B; Sorokin D; Richnow HH; Finster K

2013-09-01

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A reconstituted light-harvesting complex from the green sulfur bacterium Chlorobium tepidum containing CsmA and bacteriochlorophyll a  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Udgivelsesdato: 2008-Feb-5 , Green sulfur bacteria possess two light-harvesting antenna systems, the chlorosome and the Fenna-Matthews-Olson (FMO) protein. In addition to self-aggregated bacteriochlorophyll (BChl) c, chlorosomes of Chlorobium tepidum contain a small amount of BChl a (ratio 100:1). The ...

Pedersen, Marie Ø; Pham, Lan; Steensgaard, Dorte B; Miller, Mette

15

Ametryne and Prometryne as Sulfur Sources for Bacteria  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Bacteria were isolated that could utilize quantitatively the s-triazine herbicide prometryne [N,N' -bis(1-methylethyl)-6-(methylthio)-1,3,5-triazine-2,4-diamine] or ametryne [N-ethyl-N'-(1-methylethyl)-6-(methylthio)-1,3,5-triazine- 2,4-diamine], or both, as a sole source of sulfur for growth. The s...

Cook, Alasdair M.; Hütter, Ralf

16

Ametryne and Prometryne as Sulfur Sources for Bacteria  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Bacteria were isolated that could utilize quantitatively the s-triazine herbicide prometryne [N,N? -bis(1-methylethyl)-6-(methylthio)-1,3,5-triazine-2,4-diamine] or ametryne [N-ethyl-N?-(1-methylethyl)-6-(methylthio)-1,3,5-triazine- 2,4-diamine], or both, as a sole source of sulfur for growth. The s...

Cook, Alasdair M.; Hütter, Ralf

17

Ametryne and prometryne as sulfur sources for bacteria.  

Science.gov (United States)

Bacteria were isolated that could utilize quantitatively the s-triazine herbicide prometryne [N,N' -bis(1-methylethyl)-6-(methylthio)-1,3,5-triazine-2,4-diamine] or ametryne [N-ethyl-N'-(1-methylethyl)-6-(methylthio)-1,3,5-triazine- 2,4-diamine], or both, as a sole source of sulfur for growth. The success of enrichments depended on previous exposure of the soil inoculum to s-triazine herbicides. Deaminoethylametryne [4-(1-methylethyl)amino-6-(methylthio)-1,3,5-triazine-2-(1H)-one], methylsulfonic acid, and sodium sulfate could also be used as sulfur sources. Utilization of a compound was quantified as the growth yield per mole of sulfur supplied. Yields were about 6 kg of protein per mol of sulfur. The product of the desulfuration of an s-triazine was identified as the corresponding hydroxy-derivative. This is the first substantiated report of the utilization of these s-triazines as sulfur sources by bacteria. PMID:16345988

Cook, A M; Hütter, R

1982-04-01

18

Ametryne and prometryne as sulfur sources for bacteria.  

UK PubMed Central (United Kingdom)

Bacteria were isolated that could utilize quantitatively the s-triazine herbicide prometryne [N,N' -bis(1-methylethyl)-6-(methylthio)-1,3,5-triazine-2,4-diamine] or ametryne [N-ethyl-N'-(1-methylethyl)-6-(methylthio)-1,3,5-triazine- 2,4-diamine], or both, as a sole source of sulfur for growth. The success of enrichments depended on previous exposure of the soil inoculum to s-triazine herbicides. Deaminoethylametryne [4-(1-methylethyl)amino-6-(methylthio)-1,3,5-triazine-2-(1H)-one], methylsulfonic acid, and sodium sulfate could also be used as sulfur sources. Utilization of a compound was quantified as the growth yield per mole of sulfur supplied. Yields were about 6 kg of protein per mol of sulfur. The product of the desulfuration of an s-triazine was identified as the corresponding hydroxy-derivative. This is the first substantiated report of the utilization of these s-triazines as sulfur sources by bacteria.

Cook AM; Hütter R

1982-04-01

19

Quantitative proteomics of Chlorobaculum tepidum : insights into the sulfur metabolism of a phototrophic green sulfur bacterium  

DEFF Research Database (Denmark)

Chlorobaculum (Cba.) tepidum is a green sulfur bacterium that oxidizes sulfide, elemental sulfur, and thiosulfate for photosynthetic growth. To gain insight into the sulfur metabolism, the proteome of Cba. tepidum cells sampled under different growth conditions has been quantified using a rapid gel-free, filter-aided sample preparation (FASP) protocol with an in-solution isotopic labeling strategy. Among the 2245 proteins predicted from the Cba. tepidum genome, approximately 970 proteins were detected in unlabeled samples, whereas approximately 630-640 proteins were detected in labeled samples comparing two different growth conditions. Wild-type cells growing on thiosulfate had an increased abundance of periplasmic cytochrome c-555 and proteins of the periplasmic thiosulfate-oxidizing SOX enzyme system when compared with cells growing on sulfide. A dsrM mutant of Cba. tepidum, which lacks the dissimilatory sulfite reductase DsrM protein and therefore is unable to oxidize sulfur globules to sulfite, was also investigated. When compared with wild type, the dsrM cells exhibited an increased abundance of DSR enzymes involved in the initial steps of sulfur globule oxidation (DsrABCL) and a decreased abundance of enzymes putatively involved in sulfite oxidation (Sat-AprAB-QmoABC). The results show that Cba. tepidum regulates the cellular levels of enzymes involved in sulfur metabolism and other electron-transferring processes in response to the availability of reduced sulfur compounds.

Falkenby, Lasse Gaarde; Szymanska, Monika

2011-01-01

20

Quantitative proteomics of Chlorobaculum tepidum: insights into the sulfur metabolism of a phototrophic green sulfur bacterium.  

Science.gov (United States)

Chlorobaculum (Cba.) tepidum is a green sulfur bacterium that oxidizes sulfide, elemental sulfur, and thiosulfate for photosynthetic growth. To gain insight into the sulfur metabolism, the proteome of Cba. tepidum cells sampled under different growth conditions has been quantified using a rapid gel-free, filter-aided sample preparation (FASP) protocol with an in-solution isotopic labeling strategy. Among the 2245 proteins predicted from the Cba. tepidum genome, approximately 970 proteins were detected in unlabeled samples, whereas approximately 630-640 proteins were detected in labeled samples comparing two different growth conditions. Wild-type cells growing on thiosulfate had an increased abundance of periplasmic cytochrome c-555 and proteins of the periplasmic thiosulfate-oxidizing SOX enzyme system when compared with cells growing on sulfide. A dsrM mutant of Cba. tepidum, which lacks the dissimilatory sulfite reductase DsrM protein and therefore is unable to oxidize sulfur globules to sulfite, was also investigated. When compared with wild type, the dsrM cells exhibited an increased abundance of DSR enzymes involved in the initial steps of sulfur globule oxidation (DsrABCL) and a decreased abundance of enzymes putatively involved in sulfite oxidation (Sat-AprAB-QmoABC). The results show that Cba. tepidum regulates the cellular levels of enzymes involved in sulfur metabolism and other electron-transferring processes in response to the availability of reduced sulfur compounds. PMID:22092713

Falkenby, Lasse G; Szymanska, Monika; Holkenbrink, Carina; Habicht, Kirsten S; Andersen, Jens S; Miller, Mette; Frigaard, Niels-Ulrik

2011-08-25

 
 
 
 
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Chlorosome antenna complexes from green photosynthetic bacteria.  

UK PubMed Central (United Kingdom)

Chlorosomes are the distinguishing light-harvesting antenna complexes that are found in green photosynthetic bacteria. They contain bacteriochlorophyll (BChl) c, d, e in natural organisms, and recently through mutation, BChl f, as their principal light-harvesting pigments. In chlorosomes, these pigments self-assemble into large supramolecular structures that are enclosed inside a lipid monolayer to form an ellipsoid. The pigment assembly is dictated mostly by pigment-pigment interactions as opposed to protein-pigment interactions. On the bottom face of the chlorosome, the CsmA protein aggregates into a paracrystalline baseplate with BChl a, and serves as the interface to the next energy acceptor in the system. The exceptional light-harvesting ability at very low light conditions of chlorosomes has made them an attractive subject of study for both basic and applied science. This review, incorporating recent advancements, considers several important aspects of chlorosomes: pigment biosynthesis, organization of pigments and proteins, spectroscopic properties, and applications to bio-hybrid and bio-inspired devices.

Orf GS; Blankenship RE

2013-06-01

22

Chlorosome antenna complexes from green photosynthetic bacteria.  

Science.gov (United States)

Chlorosomes are the distinguishing light-harvesting antenna complexes that are found in green photosynthetic bacteria. They contain bacteriochlorophyll (BChl) c, d, e in natural organisms, and recently through mutation, BChl f, as their principal light-harvesting pigments. In chlorosomes, these pigments self-assemble into large supramolecular structures that are enclosed inside a lipid monolayer to form an ellipsoid. The pigment assembly is dictated mostly by pigment-pigment interactions as opposed to protein-pigment interactions. On the bottom face of the chlorosome, the CsmA protein aggregates into a paracrystalline baseplate with BChl a, and serves as the interface to the next energy acceptor in the system. The exceptional light-harvesting ability at very low light conditions of chlorosomes has made them an attractive subject of study for both basic and applied science. This review, incorporating recent advancements, considers several important aspects of chlorosomes: pigment biosynthesis, organization of pigments and proteins, spectroscopic properties, and applications to bio-hybrid and bio-inspired devices. PMID:23761131

Orf, Gregory S; Blankenship, Robert E

2013-06-13

23

Thioploca spp: filamentous sulfur bacteria with nitrate vacuoles  

DEFF Research Database (Denmark)

Thioploca spp. are multicellular, filamentous, colorless sulfur bacteria inhabiting freshwater and marine sediments. They have elemental sulfur inclusions similar to the phylogenetically closely related Beggiatoa, but in contrast to these they live in bundles surrounded by a common sheath. Vast communities of large Thioploca species live along the Pacific coast of South America and in other upwelling areas of high organic matter sedimentation with bottom waters poor in oxygen and rich in nitrate. Each cell of these thioplocas harbors a large liquid vacuole which is used as a storage for nitrate with a concentration of lip to 506 mM. The nitrate is used as an electron acceptor for sulfide oxidation and the bacteria may grow autotrophically or mixotrophically using acetate or other organic molecules as carbon source. The filaments stretch up into the overlying seawater, from which they take up nitrate, and then glide down 5-15 cm deep into the sediment through their sheaths to oxidize sulfide formed by intensive sulfate reduction. New major occurrences have bren found in recent years, both in lakes and in the ocean, and have stimulated the interest in these fascinating bacteria. (C) 1999 Federation of European Microbiological Societies. Published by Elsevier Science B.V. All rights reserved.

JØrgensen, BB; Gallardo, VA

1999-01-01

24

Degradation of oil shale by sulfur-oxidizing bacteria.  

UK PubMed Central (United Kingdom)

Approximately 40% of oil shale can be solubilized by the action of sulfur-oxidizing bacteria. Thiobacillus thiooxidans and Thiobacillus concretivorous are equally effective in solubilization. Continuous leaching experiments show that this process can be completed within 14 days. The growth of Thiobacillus and the production of acid were measured under several conditions. Almost all of the CaMg(CO(3))(2) was removed by this process, leaving a complex of silica and kerogen that could be burned as low-energy fuel. The silica-kerogen complex had not yet been biologically degraded.

Findley J; Appleman MD; Yen TF

1974-09-01

25

Characterization of the group 1 and group 2 sigma factors of the green sulfur bacterium Chlorobium tepidum and the green non-sulfur bacterium Chloroflexus aurantiacus.  

UK PubMed Central (United Kingdom)

The group 1 and group 2 sigma70-type sigma factors of the green sulfur bacterium Chlorobium tepidum and of the green nonsulfur bacterium Chloroflexus aurantiacus were cloned and characterized. Cb. tepidum was found to contain one sigma70-type sigma factor; the expression of the gene was analyzed by Northern blot hybridization and primer-extension mapping. Cf. aurantiacus has genes encoding four sigma factors of groups 1 and 2. The expression of these genes was examined in cells grown aerobically and anaerobically. The sigC gene was expressed at approximately equal levels under both conditions, resulting in its designation as the group 1 sigma factor of this organism. The only other detectable transcripts arose from the sigB gene, which was expressed at higher levels during aerobic growth. A phylogenetic tree was obtained using the group 1 sigma factors of Cb. tepidum, Cf. aurantiacus, and diverse eubacteria as the molecular marker. The resulting phylogenetic tree shows that Cb. tepidum and Cf. aurantiacus are related to each other and to the cyanobacteria. The relationship of the group 2 sigma factors of Cf. aurantiacus and the cyanobacteria was more specifically examined phylogenetically. The group 2 sigma factors of Cf. aurantiacus probably arose by gene duplication events after the split of the green nonsulfur bacteria from other photosynthetic eubacteria.

Gruber TM; Bryant DA

1998-10-01

26

[Fe]-hydrogenases in green algae: photo-fermentation and hydrogen evolution under sulfur deprivation  

Energy Technology Data Exchange (ETDEWEB)

Recent studies indicate that [Fe]-hydrogenases and H{sub 2} metabolism are widely distributed among green algae. The enzymes are simple structured and catalyze H{sub 2} evolution with similar rates than the more complex [Fe]-hydrogenases from bacteria. Different green algal species developed diverse strategies to survive under sulfur deprivation. Chlamydomonas reinhardtii evolves large quantities of hydrogen gas in the absence of sulfur. In a sealed culture of C. reinhardtii, the photosynthetic O{sub 2} evolution rate drops below the rate of respiratory O{sub 2} consumption due to a reversible inhibition of photosystem II, thus leading to an intracellular anaerobiosis. The algal cells survive under these anaerobic conditions by switching their metabolism to a kind of photo-fermentation. Although possessing a functional [Fe]-hydrogenase gene, the cells of Scenedesmus obliquus produce no significant amounts of H{sub 2} under S-depleted conditions. Biochemical analyses indicate that S. obliquus decreases almost the complete metabolic activities while maintaining a low level of respiratory activity. (author)

Winkler, M.; Hemschemeier, A.; Happe, T. [Botanisches Institut der Universitat Bonn (Germany); Gotor, C. [CSIC y Universidad de Sevilla (Spain). Instituto de Bioquimica Vegetal y Fotosintesis; Melis, A. [University of California, Berkeley, CA (United States). Department of Plant and Microbial Biology

2002-12-01

27

Effects of oxidants and reductants on the efficiency of excitation transfer in green photosynthetic bacteria.  

UK PubMed Central (United Kingdom)

The efficiency of energy transfer in chlorosome antennas in the green sulfur bacteria Chlorobium vibrioforme and Chlorobium limicola was found to be highly sensitive to the redox potential of the suspension. Energy transfer efficiencies were measured by comparing the absorption spectrum of the bacteriochlorophyll c or d pigments in the chlorosome to the excitation spectrum for fluorescence arising from the chlorosome baseplate and membrane-bound antenna complexes. The efficiency of energy transfer approaches 100% at low redox potentials induced by addition of sodium dithionite or other strong reductants, and is lowered to 10-20% under aerobic conditions or after addition of a variety of membrane-permeable oxidizing agents. The redox effect on energy transfer is observed in whole cells, isolated membranes and purified chlorosomes, indicating that the modulation of energy transfer efficiency arises within the antenna complexes and is not directly mediated by the redox state of the reaction center. It is proposed that chlorosomes contain a component that acts as a highly quenching center in its oxidized state, but is an inefficient quencher when reduced by endogenous or exogenous reductants. This effect may be a control mechanism that prevents cellular damage resulting from reaction of oxygen with reduced low-potential electron acceptors found in the green sulfur bacteria. The redox modulation effect is not observed in the green gliding bacterium Chloroflexus aurantiacus, which contains chlorosomes but does not contain low-potential electron acceptors.

Wang J; Brune DC; Blankenship RE

1990-02-01

28

Motility patterns of filamentous sulfur bacteria, Beggiatoa spp.  

DEFF Research Database (Denmark)

The large sulfur bacteria, Beggiatoa spp., live on the oxidation of sulfide with oxygen or nitrate, but avoid high concentrations of both sulfide and oxygen. As gliding filaments, they rely on reversals in the gliding direction to find their preferred environment, the oxygen–sulfide interface.We observed the chemotactic patterns of single filaments in a transparent agar medium and scored their reversals and the glided distances between reversals. Filaments within the preferred microenvironment glided distances shorter than their own length between reversals that anchored them in their position as a microbial mat. Filaments in the oxic region above the mat or in the sulfidic, anoxic region below the mat glided distances longer than the filament length between reversals. This reversal behavior resulted in a diffusion-like spreading of the filaments. A numerical model of such gliding filaments was constructed based on our observations. The model was applied to virtual filaments in the oxygen- and sulfide-free zone of the sediment, which is a main habitat of Beggiatoa in the natural environment. The model predicts a long residence time of the virtual filament in the suboxic zone and explains why Beggiatoa accumulate high nitrate concentrations in internal vacuoles as an alternative electron acceptor to oxygen.

Dunker, Rita; RØy, Hans

2011-01-01

29

Modeling the electron transport chain of purple non-sulfur bacteria  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Purple non-sulfur bacteria (Rhodospirillaceae) have been extensively employed for studying principles of photosynthetic and respiratory electron transport phosphorylation and for investigating the regulation of gene expression in response to redox signals. Here, we use mathematical modeling to evalu...

Klamt, Steffen; Grammel, Hartmut; Straube, Ronny; Ghosh, Robin; Gilles, Ernst Dieter

30

Transmission electron microscopic study on supramolecular nanostructures of bacteriochlorophyll self-aggregates in chlorosomes of green photosynthetic bacteria.  

UK PubMed Central (United Kingdom)

Supramolecular nanostructures of bacteriochlorophyll (BChl) self-aggregates in major light-harvesting complexes (chlorosomes) of green photosynthetic bacteria were successfully observed by freeze-fracture transmission electron microscope. Rod-shaped nanostructures with approximately 10 nm in diameter could be visualized in three types of green sulfur bacteria (Chlorobium). Diameter of the rod-shaped nanostructures in Chlorobium chlorosomes was independent of the molecular structures of their light-harvesting pigments, namely BChl-c or d. In contrast, chlorosomes of the green filamentous bacterium Chloroflexus aurantiacus had rod-shaped nanostructures with approximately 5 nm in diameter. The present results support that BChl self-aggregates in chlorosomes form rod-shaped nanostructures called rod-elements with approximately 10- and 5-nm diameters for Chlorobium and Chloroflexus, respectively.

Saga Y; Tamiaki H

2006-08-01

31

Filamentous sulfur bacteria preserved in modern and ancient phosphatic sediments: implications for the role of oxygen and bacteria in phosphogenesis.  

UK PubMed Central (United Kingdom)

Marine phosphate-rich sedimentary deposits (phosphorites) are important geological reservoirs for the biologically essential nutrient phosphorous. Phosphorites first appear in abundance approximately 600 million years ago, but their proliferation at that time is poorly understood. Recent marine phosphorites spatially correlate with the habitats of vacuolated sulfide-oxidizing bacteria that store polyphosphates under oxic conditions to be utilized under sulfidic conditions. Hydrolysis of the stored polyphosphate results in the rapid precipitation of the phosphate-rich mineral apatite-providing a mechanism to explain the association between modern phosphorites and these bacteria. Whether sulfur bacteria were important to the formation of ancient phosphorites has been unresolved. Here, we present the remains of modern sulfide-oxidizing bacteria that are partially encrusted in apatite, providing evidence that bacterially mediated phosphogenesis can rapidly permineralize sulfide-oxidizing bacteria and perhaps other types of organic remains. We also describe filamentous microfossils that resemble modern sulfide-oxidizing bacteria from two major phosphogenic episodes in the geologic record. These microfossils contain sulfur-rich inclusions that may represent relict sulfur globules, a diagnostic feature of modern sulfide-oxidizing bacteria. These findings suggest that sulfur bacteria, which are known to mediate the precipitation of apatite in modern sediments, were also present in certain phosphogenic settings for at least the last 600 million years. If polyphosphate-utilizing sulfide-oxidizing bacteria also played a role in the formation of ancient phosphorites, their requirements for oxygen, or oxygen-requiring metabolites such as nitrate, might explain the temporal correlation between the first appearance of globally distributed marine phosphorites and increasing oxygenation of Neoproterozoic oceans.

Bailey JV; Corsetti FA; Greene SE; Crosby CH; Liu P; Orphan VJ

2013-09-01

32

Filamentous sulfur bacteria preserved in modern and ancient phosphatic sediments: implications for the role of oxygen and bacteria in phosphogenesis.  

Science.gov (United States)

Marine phosphate-rich sedimentary deposits (phosphorites) are important geological reservoirs for the biologically essential nutrient phosphorous. Phosphorites first appear in abundance approximately 600 million years ago, but their proliferation at that time is poorly understood. Recent marine phosphorites spatially correlate with the habitats of vacuolated sulfide-oxidizing bacteria that store polyphosphates under oxic conditions to be utilized under sulfidic conditions. Hydrolysis of the stored polyphosphate results in the rapid precipitation of the phosphate-rich mineral apatite-providing a mechanism to explain the association between modern phosphorites and these bacteria. Whether sulfur bacteria were important to the formation of ancient phosphorites has been unresolved. Here, we present the remains of modern sulfide-oxidizing bacteria that are partially encrusted in apatite, providing evidence that bacterially mediated phosphogenesis can rapidly permineralize sulfide-oxidizing bacteria and perhaps other types of organic remains. We also describe filamentous microfossils that resemble modern sulfide-oxidizing bacteria from two major phosphogenic episodes in the geologic record. These microfossils contain sulfur-rich inclusions that may represent relict sulfur globules, a diagnostic feature of modern sulfide-oxidizing bacteria. These findings suggest that sulfur bacteria, which are known to mediate the precipitation of apatite in modern sediments, were also present in certain phosphogenic settings for at least the last 600 million years. If polyphosphate-utilizing sulfide-oxidizing bacteria also played a role in the formation of ancient phosphorites, their requirements for oxygen, or oxygen-requiring metabolites such as nitrate, might explain the temporal correlation between the first appearance of globally distributed marine phosphorites and increasing oxygenation of Neoproterozoic oceans. PMID:23786451

Bailey, J V; Corsetti, F A; Greene, S E; Crosby, C H; Liu, P; Orphan, V J

2013-06-21

33

A model of the protein-pigment baseplate complex in chlorosomes of photosynthetic green bacteria  

DEFF Research Database (Denmark)

In contrast to photosynthetic reaction centers, which share the same structural architecture, more variety is found in the light-harvesting antenna systems of phototrophic organisms. The largest antenna system described, so far, is the chlorosome found in anoxygenic green bacteria, as well as in a recently discovered aerobic phototroph. Chlorosomes are the only antenna system, in which the major light-harvesting pigments are organized in self-assembled supramolecular aggregates rather than on protein scaffolds. This unique feature is believed to explain why some green bacteria are able to carry out photosynthesis at very low light intensities. Encasing the chlorosome pigments is a protein-lipid monolayer including an additional antenna complex: the baseplate, a two-dimensional paracrystalline structure containing the chlorosome protein CsmA and bacteriochlorophyll a (BChl a). In this article, we review current knowledge of the baseplate antenna complex, which physically and functionally connects the chlorosome pigments to the reaction centers via the Fenna-Matthews-Olson protein, with special emphasis on the well-studied green sulfur bacterium Chlorobaculum tepidum (previously Chlorobium tepidum). A possible role for the baseplate in the biogenesis of chlorosomes is discussed. In the final part, we present a structural model of the baseplate through combination of a recent NMR structure of CsmA and simulation of circular dichroism and optical spectra for the CsmA-BChl a complex.

Pedersen, Marie Ø; Linnanto, Juha

2010-01-01

34

[On structure and function of "chlorosoma" of green bacteria].  

Science.gov (United States)

An assertion is substantiated that what is widely termed as chlorosoma of green bacteria--is not a bioparticle, but simply microscopic bacteriochlorophyll-c crystals. Apparently the creation of "chlorosoma" represents the first mostly unsuccessful evolutionary attempt to produce the regulatory mechanism in photosynthesis, which should react to the variations in the intensity of solar light reaching earth surface. It could not be successful without bacteriochlorophyll cooperation with proteins. PMID:23035541

Borisov, A Iu

35

Structure, Function and Reconstitution of Antenna Complexes of Green Photosynthetic Bacteria  

Energy Technology Data Exchange (ETDEWEB)

Most chlorophyll-type pigments in a photosynthetic organism function as an antenna, absorbing light and transferring excitations to a photochemical reaction center where energy storage takes place by a series of chemical reactions. The green photosynthetic bacteria are characterized by large antenna complexes known as chlorosomes, in which pigment-pigment interactions are of dominant importance. The overall objective of this project is to determine the mechanisms of excitation transfer and regulation of this unique antenna system, including how it is integrated into the rest of the photosynthetic energy transduction apparatus. Techniques that are being used in this research include biochemical analysis, spectroscopy, microscopy, X-ray structural studies, and reconstitution from purified components. Our recent results indicate that the chlorosome baseplate structure, which is the membrane attachment site for the chlorosome to the membrane, is a unique pigment-protein that contains large amounts of carotenoids and small amounts of bacteriochlorophyll a. Reconstitution of directed energy transfer in chlorosomes will be carried out using purified baseplates and oligomeric pigments. The integral membrane B808-866 antenna complex from Chloroflexus aurantiacus and the Fenna-Matthews-Olson protein-reaction center complex from green sulfur bacteria will be characterized by spectroscopic and structural techniques.

Blankenship, Robert E.

2005-06-10

36

Extremely acidophilic sulfur-oxidizing bacteria applied in biotechnological processes for gas purification.  

UK PubMed Central (United Kingdom)

Extreme acidophilic (pH ~ 0.25) microorganisms have been studied and applied to treat volatile sulfur emissions like carbon disulfide. These microorganisms provide opportunities for biomass control and recycling of sulfuric acid using extremely low pH operating conditions as shown in 70 L bench-scale bioreactors. Applying the extreme acidophilic bacteria in full-scale bioreactors treating carbon disulfide in combination with hydrogen sulfide emissions from industrial processes like the viscose industry was shown to be effective with average total sulfur removal efficiency above 90%.

Kraakman NJ; Pol A; Smeulders MJ; Jetten MS; Op Den Camp HJ

2012-01-01

37

Polypeptides of reaction center complexes from green photosynthetic bacteria  

Energy Technology Data Exchange (ETDEWEB)

Unit-membrane vesicles containing photosynthetic reaction centers from the green sulfur bacterium, Chlorobium limicola f. thiosulfatophilum, were treated successively with Triton X-100 and guanidine HCl to yield non-membranous particles. Twenty one polypeptide components ranging from 12 to 106 x 10/sup 3/ were resolved in all three preparations by sodium dodecyl sulfate polyacrylamide gel electrophoresis. The number of molecules per reaction center was estimated for every polypeptide in each preparation. For eight polypeptides, the levels remained approximately constant. Of these eight polypeptides only five (25.0, 25.5, 38.5, 69, and 93 x 10/sup 3/) had the possibility of a specific association with the reaction center.

Bernstein, J.D.; Olson, J.M.

1983-01-01

38

Electric current generation by sulfur-reducing bacteria in microbial-anode fuel cell  

Science.gov (United States)

Sulfur - reducing bacteria are a part of normal microflora of natural environment. Their main function is supporting of reductive stage of sulfur cycle by hydrogen sulfide production in the process of dissimilative sulfur-reduction. At the same time these bacteria completely oxidize organic compounds with CO2 and H2O formation. It was shown that they are able to generate electric current in the two chamber microbial-anode fuel cell (MAFC) by interaction between these two processes. Microbial-anode fuel cell on the basis of sulfur- and ferric iron-reducing Desulfuromonas acetoxidans bacteria has been constructed. It has been shown that the amount of electricity generation by investigated bacteria is influenced by the concentrations of carbon source (lactate) and ferric iron chloride. The maximal obtained electric current and potential difference between electrodes equaled respectively 0.28-0.29 mA and 0.19-0.2 V per 0.3 l of bacterial suspension with 0.4 g/l of initial biomass that was grown under the influence of 0.45 mM of FeCl3 and 3 g/l of sodium lactate as primal carbon source. It has also been shown that these bacteria are resistant to different concentrations of silver ions.

Vasyliv, Oresta M.; Bilyy, Oleksandr I.; Ferensovych, Yaroslav P.; Hnatush, Svitlana O.

2012-10-01

39

Oxygen uncouples light absorption by the chlorosome antenna and photosynthetic electron transfer in the green sulfur bacterium chlorobium tepidum  

UK PubMed Central (United Kingdom)

In photosynthetic green sulfur bacteria excitation energy is transferred from large bacteriochlorophyll (BChl) c chlorosome antennas via small BChl a antennas to the reaction centers which then transfer electrons from cytochrome c to low-potential iron-sulfur proteins. Under oxidizing conditions a reversible mechanism is activated in the chlorosomes which quenches excited BChl c. We used flash-induced cytochrome c oxidation to investigate the effect of this quenching on photosynthetic electron transfer in whole cells of Chlorobium tepidum. The extent of cytochrome c photooxidation under aerobic conditions decreased to approx. 3% of that under anaerobic conditions when BChl c was excited under light-limiting conditions. Photooxidation obtained by excitation of BChl a was similar under aerobic and anaerobic conditions. We interpret this drastic decrease in energy transfer from BChl c to the reaction center as a consequence of the quenching mechanism which is activated by O2. This reversible uncoupling of the chlorosome antenna might prevent formation of toxic reactive oxygen species from photosynthetically produced reductants under aerobic conditions. The green filamentous bacterium Chloroflexus aurantiacus also contains chlorosomes but energy transfer from the BChl c and BChl a antennas to the reaction center in this species was not affected by O2.

Frigaard NU; Matsuura K

1999-06-01

40

Chemolithotrophic Sulfur-Oxidizing Bacteria from the Galapagos Rift Hydrothermal Vents †  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Three distinct physiological types of sulfur-oxidizing bacteria were enriched and isolated from samples collected at several deep-sea hydrothermal vents (2,550 m) of the Galapagos Rift ocean floor spreading center. Twelve strains of the obligately chemolithotrophic genus Thiomicrospira were obtained...

Ruby, E. G.; Wirsen, C. O.; Jannasch, H. W.

 
 
 
 
41

Physiological and phylogenetic studies of thermophilic, hydrogen and sulfur oxidizing bacteria isolated from Icelandic geothermal areas  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Four thermophilic hydrogen oxidizing bacteria were isolated from various hot-springs in Grensdalur, Hveragerði, SW-Iceland. The strains were investigated with respect to phylogenetics, physiology, hydrogen uptake rates, biomass yield and sulfur metabolism. Phylogenetic studies of the isolates were...

Hildur Vésteinsdóttir

42

Bacteria involved in sulfur amendment oxidation and acidification processes of alkaline 'alperujo' compost.  

Science.gov (United States)

Eight strains of sulfur oxidizing bacteria were isolated from alkaline 'alperujo' compost, seven being identified as Paracoccus thiocyanatus and one as Halothiobacillus neapolitanus. This was the first time that P. thiocyanatus was isolated from mature compost. Acidification capability of isolated strains was compared with type strains H. neapolitanus CIP104769, Thiobacillus denitrificans CIP104767 and Thiomonas intermedia CIP104401. Indigenous P. thiocyanatus strains were as much as or more efficient for acidifying compost than type strains. Sulfur oxidizing population naturally occurring in compost showed maximum acidification efficiency and no extra effect was found with the help of type strains. pH reduction caused by S? was paralleled by a decrease in CaCO3 and an increase in CaSO4 and salinity levels. A remarkable increase in cultivable sulfur oxidizing bacteria population along with the acidification process was also recorded. Amended compost showed a range of chemical and biological characteristics suitable for use as container media constituent. PMID:20970324

García-de-la-Fuente, R; Cuesta, G; Sanchís-Jiménez, E; Botella, S; Abad, M; Fornes, F

2010-10-20

43

Bacteria associated with iron seeps in a sulfur-rich, neutral pH, freshwater ecosystem.  

Science.gov (United States)

The freshwater nature reserve De Bruuk is an iron- and sulfur-rich minerotrophic peatland containing many iron seeps and forms a suitable habitat for iron and sulfur cycle bacteria. Analysis of 16S rRNA gene-based clone libraries showed a striking correlation of the bacterial population of samples from this freshwater ecosystem with the processes of iron reduction (genus Geobacter), iron oxidation (genera Leptothrix and Gallionella) and sulfur oxidation (genus Sulfuricurvum). Results from fluorescence in situ hybridization analyses with a probe specific for the beta-1 subgroup of Proteobacteria, to which the genera Leptothrix and Gallionella belong, and newly developed probes specific for the genera Geobacter and Sulfuricurvum, supported the clone library data. Molecular data suggested members of the epsilonproteobacterial genus Sulfuricurvum as contributors to the oxidation of reduced sulfur compounds in the iron seeps of De Bruuk. In an evaluation of anaerobic dimethyl sulfide (DMS)-degrading activity of sediment, incubations with the electron acceptors sulfate, ferric iron and nitrate were performed. The fastest conversion of DMS was observed with nitrate. Further, a DMS-oxidizing, nitrate-reducing enrichment culture was established with sediment material from De Bruuk. This culture was dominated by dimorphic, prosthecate bacteria, and the 16S rRNA gene sequence obtained from this enrichment was closely affiliated with Hyphomicrobium facile, which indicates that the Hyphomicrobium species are capable of both aerobic and nitrate-driven DMS degradation. PMID:18754044

Haaijer, Suzanne C M; Harhangi, Harry R; Meijerink, Bas B; Strous, Marc; Pol, Arjan; Smolders, Alfons J P; Verwegen, Karin; Jetten, Mike S M; Op den Camp, Huub J M

2008-08-28

44

Insights into the genome of large sulfur bacteria revealed by analysis of single filaments  

DEFF Research Database (Denmark)

Marine sediments are frequently covered by mats of the filamentous Beggiatoa and other large nitrate-storing bacteria that oxidize hydrogen sulfide using either oxygen or nitrate, which they store in intracellular vacuoles. Despite their conspicuous metabolic properties and their biogeochemical importance, little is known about their genetic repertoire because of the lack of pure cultures. Here, we present a unique approach to access the genome of single filaments of Beggiatoa by combining whole genome amplification, pyrosequencing, and optical genome mapping. Sequence assemblies were incomplete and yielded average contig sizes of approximately 1 kb. Pathways for sulfur oxidation, nitrate and oxygen respiration, and CO2 fixation confirm the chemolithoautotrophic physiology of Beggiatoa. In addition, Beggiatoa potentially utilize inorganic sulfur compounds and dimethyl sulfoxide as electron acceptors. We propose a mechanism of vacuolar nitrate accumulation that is linked to proton translocation by vacuolar-type ATPases. Comparative genomics indicates substantial horizontal gene transfer of storage, metabolic, and gliding capabilities between Beggiatoa and cyanobacteria. These capabilities enable Beggiatoa to overcome non-overlapping availabilities of electron donors and acceptors while gliding between oxic and sulfidic zones. The first look into the genome of these filamentous sulfur-oxidizing bacteria substantially deepens the understanding of their evolution and their contribution to sulfur and nitrogen cycling in marine sediments.

Mussmann, Marc; Hu, Fen Z.

2007-01-01

45

Transcriptome for Photobiological Hydrogen Production Induced by Sulfur Deprivation in the Green Alga Chlamydomonas reinhardtii? †  

Science.gov (United States)

Photobiological hydrogen production using microalgae is being developed into a promising clean fuel stream for the future. In this study, microarray analyses were used to obtain global expression profiles of mRNA abundance in the green alga Chlamydomonas reinhardtii at different time points before the onset and during the course of sulfur-depleted hydrogen production. These studies were followed by real-time quantitative reverse transcription-PCR and protein analyses. The present work provides new insights into photosynthesis, sulfur acquisition strategies, and carbon metabolism-related gene expression during sulfur-induced hydrogen production. A general trend toward repression of transcripts encoding photosynthetic genes was observed. In contrast to all other LHCBM genes, the abundance of the LHCBM9 transcript (encoding a major light-harvesting polypeptide) and its protein was strongly elevated throughout the experiment. This suggests a major remodeling of the photosystem II light-harvesting complex as well as an important function of LHCBM9 under sulfur starvation and photobiological hydrogen production. This paper presents the first global transcriptional analysis of C. reinhardtii before, during, and after photobiological hydrogen production under sulfur deprivation.

Nguyen, Anh Vu; Thomas-Hall, Skye R.; Malnoe, Alizee; Timmins, Matthew; Mussgnug, Jan H.; Rupprecht, Jens; Kruse, Olaf; Hankamer, Ben; Schenk, Peer M.

2008-01-01

46

Accelerated evolutionary rate in sulfur-oxidizing endosymbiotic bacteria associated with the mode of symbiont transmission.  

UK PubMed Central (United Kingdom)

The nearly neutral theory of molecular evolution predicts that the rate of nucleotide substitution should accelerate in small populations at sites under low selective constraint. We examined these predictions with respect to the relative population sizes for three bacterial life histories within chemolithoautotrophic sulfur-oxidizing bacteria: (1) free-living bacteria, (2) environmentally captured symbionts, and (3) maternally transmitted symbionts. Both relative rates of nucleotide substitution and relative ratios of loop, stem, and domain substitutions from 1,165 nt of the small-subunit 16S rDNA were consistent with expectations of the nearly neutral theory. Relative to free-living sulfur-oxidizing autotrophic bacteria, the maternally transmitted symbionts have faster substitution rates overall and also in low-constraint domains of 16S rDNA. Nucleotide substitition rates also differ between loop and stem positions. All of these findings are consistent with the predictions that these symbionts have relatively small effective population sizes. In contrast, the rates of nucleotide substitution in environmentally captured symbionts are slower, particularly in high-constraint domains, than in free-living bacteria.

Peek AS; Vrijenhoek RC; Gaut BS

1998-11-01

47

INFLUENCE OF ELEMENTAL SULFUR, ORGANIC MATTER, SULFUR OXIDIZING BACTERIA AND CABRONITE ALONE OR IN COMBINATION ON COWPEA PLANTS AND THE USED SOIL  

Directory of Open Access Journals (Sweden)

Full Text Available A field experiment was carried out at the Abis Experimental Farm, Faculty of Agriculture, Alexandria University. The soil (clay loam) was treated with sulfur oxidizing bacteria (S.O.B.), municipal refuse compost (O.M), elemental sulfur (E.S) and Cabronite, each alone or in combination. Seeds of cowpea were inoculated with the specific root nodule bacteria (Okadin) before planting.According to the obtained results the following results could be concluded:All the used treatments i.e E.S; O.M; Cabronite and S.O.B. each alone or in combination significantly increased the dry weights of cowpea plants and also increased the roots, shoots and seeds as well the used soil content of S, P, K, N, Fe, Mn, Zn and Cu.The application of elemental sulfur with S.O.B. to the soil improved the availability and plant uptake of macro and micro nutrients by cowpea plants as well nutrients content of the used soil.Application of O.M maximized the role of sulfur and S.O.B.It could be concluded that the best treatment which clearly affected growth, nodulation, seed yield and nutrients content of cowpea plants as well as the elemental content of the used soil was elemental sulfur (E.S) + organic matter (O.M) and sulfur oxidizing bacteria (S.O.B.) treatment.

El-Halfawi M. H.; Ibrahim S. A.; Hala Kandil

2010-01-01

48

EFFECT OF SOLE AND ASSOCIATIVE ACTIONS OF ELEMENTAL SULFUR AND INOCULATION SULFUR OXIDIZING BACTERIA ON GROWTH AND NUTRIENTS CONTENTS OF PEPPER PLANTS AND THE USED SOILS  

Directory of Open Access Journals (Sweden)

Full Text Available A pot experiment was conducted to study the effect of elemental sulfur (E.S) rate (2.5 g/kg soil) and sulfur oxidizing bacteria on pepper plant and some chemical properties of two representative soil samples varying in their texture and CaCO3 content. Pepper was grown in Shobrakheet clay loam and Nobaria sandy loam soils for 50 days. Each soil was treated with elemental sulfur (2.5 g kg-1 soil) and inoculated with two sulfur oxidizing bacteria (S.O.B. No.8 and S.O.B. ATCC 8158). Elemental sulfur with or without sulfur oxidizing bacteria increased shoot dry weights of pepper plants as compared with control. The highest effect was observed with E.S + ATCC 8158 treatment which resulted in increasing the pepper shoot dry weights from 1.36 to 2.08 g pot-1 with the clay loam soil and from 0.77 to 1.37 g pot-1 with the sandy loam soil. The same treatment resulted in the highest plant content of S, N, P, K and micronutrients.

S. A. Ibrahim; M. H. El-Halfawi; Hala Kandil

2011-01-01

49

Chemolithotrophic bacteria in copper ores leached at high sulfuric Acid concentration.  

UK PubMed Central (United Kingdom)

Extensive bacterial growth was observed when copper sulfide ores were leached with 0.6 N sulfuric acid. The bacterial population developed in this condition was examined by characterization of the spacer regions between the 16S and 23S rRNA genetic loci obtained after PCR amplification of the DNA extracted from the leached ore. The spacers observed had the sizes found in strains of "Leptospirillum ferrooxidans" and Thiobacillus thiooxidans, except for a larger one, approximately 560 bp long, that was not observed in any of the strains examined, including those of Thiobacillus ferrooxidans. The bacteria with this last spacer were selected after culturing in mineral and elemental sulfur media containing 0.7 N sulfuric acid. The spacer and the 16S ribosomal DNA of this isolate were sequenced and compared with those in species commonly found in bioleaching processes. Though the nucleotide sequence of the spacer showed an extensive heterologous region with T. thiooxidans, the sequence of its 16S rDNA gene indicated a close relationship (99.85%) with this species. These results indicate that a population comprised of bacterial strains closely related to T. thiooxidans and of another strain, possibly related to "L. ferrooxidans," can develop during leaching at high sulfuric acid concentration. Iron oxidation in this condition is attributable to "L. ferrooxidans" and not T. ferrooxidans, based on the presence of spacers with the "L. ferrooxidans" size range and the absence of spacers characteristic of T. ferrooxidans.

Vasquez M; Espejo RT

1997-01-01

50

DELAYED LIGHT PRODUCTION BY BLUE-GREEN ALGAE, RED ALGAE, AND PURPLE BACTERIA  

Digital Repository Infrastructure Vision for European Research (DRIVER)

1. Blue-green algae, red algae, and purple bacteria all show the emission of delayed light. 2. The action spectra for the production of delayed light by three species of blue-green algae have one broad band with a peak at 620 mµ. 3. The action spectrum for production of delayed light by the red alg...

Arnold, William; Thompson, Jane

51

Sulfur  

Energy Technology Data Exchange (ETDEWEB)

A wide-ranging survey of the current state of knowledge of sulfur and its compounds, this book covers inorganic, organic, organometallic, industrial, biochemical and geochemical aspects of sulfur chemistry. The significance of sulfur compounds in connection with health, pollution, energy conversion and the exploration of resources is discussed. The role of sulfur compounds in microbiology, medicine, materials sciences, and even history and art is reviewed.

Muller, A.; Krebs, B.

1984-01-01

52

Isolation of lactic acid bacteria for its possible use in the fermentation of green algerian olives  

Digital Repository Infrastructure Vision for European Research (DRIVER)

This study was undertaken with the aim of obtaining lactic acid bacteria with the ability to ferment olives for possible use as starter cultures. For this reason, 32 isolates of lactic acid bacteria isolated from the spontaneous fermentation of green olives were characterized and identified on the b...

Mourad, Kacem; Halima, Zadi-Karam; Nour-Eddine, Karam

53

Who is in there? : exploration of endophytic bacteria within the siphonous green seaweed Bryopsis (Bryopsidales, Chlorophyta)  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Associations between marine seaweeds and bacteria are widespread, with endobiotic bacterial-algal interactions being described for over 40 years. Also within the siphonous marine green alga Bryopsis, intracellular bacteria have been visualized by electron microscopy in the early '70s, but were up to...

Hollants, Joke; Leroux, Olivier; Leliaert, Frédérik; Decleyre, Helen; De Clerck, Olivier; Willems, Anne

54

Effect of organics and alkalinity on the sulfur oxidizing bacteria (SOB) biosensor.  

UK PubMed Central (United Kingdom)

The environmental risk assessment of toxic chemicals in stream water requires the use of a low cost standardized toxicity bioassay. Here, a biosensor for detection of toxic chemicals in stream water was studied using sulfur oxidizing bacteria (SOB) in continuous mode. The biosensor depends on the ability of SOB to oxidize sulfur particles under aerobic conditions to produce sulfuric acid. The reaction results in an increase in electrical conductivity (EC) and a decrease in pH. The biosensor is based on the inhibition of SOB in the presence of toxic chemicals by measuring changes in EC and pH. We found that the SOB biosensor can detect Cr(6+)at a low concentration (50 ppb) which is lower than many whole-cell biosensors. The effect of organic material in real stream water on SOB activity was studied. Due to the presence of mixotrophic SOB, we found that the presence of organic matter increases SOB activity which decreases the biosensor start up period. Low alkalinity (22 mg L(-1) CaCO(3)) increased effluent EC and decreased effluent pH which is optimal for biosensor operation. While at high alkalinity (820 mg L(-1) CaCO(3), the activity of SOB little decreased. We found that system can detect 50 ppb of Cr(6+) at low alkalinity (22 mg L(-1) CaCO(3)) in few hours while, complete inhibition was observed after 35 h of operation at high alkalinity (820 mg L(-1) CaCO(3)).

Hassan SH; Van Ginkel SW; Oh SE

2013-01-01

55

Comparative proteomics and activity of a green sulfur bacterium across the water column of Lake Cadagno, Switzerland  

DEFF Research Database (Denmark)

Primary production in the meromictic Lake Cadagno, Switzerland, is dominated by anoxygenic photosynthesis. The green sulfur bacterium Chlorobium clathratiforme is the dominant phototrophic organism in the lake, comprising more than half of the bacterial population, and its biomass increases 3.8-fold over the summer. Cells from four positions in the water column were used for comparative analysis of the Chl. clathratiforme proteome in order to investigate changes in protein composition in response to the chemical and physical gradient in their environment, with special focus on how the bacteria survive in the dark. Although metagenomic data are not available for Lake Cadagno, proteome analysis was possible based on the completely sequenced genome of an isolated strain of Chl. clathratiforme. Using LC-MS/MS we identified 1321 Chl. clathratiforme proteins in Lake Cadagno and quantitatively compared 621 of these in the four samples. Our results showed that compared with cells obtained from the photic zone, cells collected from the dark part of the water column had the same expression level of key enzymes involved in carbon metabolism and photosynthetic light harvesting. However, most proteins participating in nitrogen and sulfur metabolism were twofold less abundant in the dark. From the proteome analysis we were able to show that Chl. clathratiforme in the photic zone contains enzymes for fixation of N2 and the complete oxidation of sulfide to sulfate while these processes are probably not active in the dark. Instead we propose that Chl. clathratiforme cells in the dark part of the water column obtain energy for maintenance from the fermentation of polyglucose. Based on the observed protein compositions we have constructed possible pathways for C, N and S metabolism in Chl. clathratiforme

Habicht, Kirsten S.; Miller, Mette

2011-01-01

56

Comparative proteomics and activity of a green sulfur bacterium across the water column of Lake Cadagno, Switzerland.  

DEFF Research Database (Denmark)

Primary production in the meromictic Lake Cadagno, Switzerland, is dominated by anoxygenic photosynthesis. The green sulfur bacterium Chlorobium clathratiforme is the dominant phototrophic organism in the lake, comprising more than half of the bacterial population, and its biomass increases 3.8-fold over the summer. Cells from four positions in the water column were used for comparative analysis of the Chl. clathratiforme proteome in order to investigate changes in protein composition in response to the chemical and physical gradient in their environment, with special focus on how the bacteria survive in the dark. Although metagenomic data are not available for Lake Cadagno, proteome analysis was possible based on the completely sequenced genome of an isolated strain of Chl. clathratiforme. Using LC-MS/MS we identified 1321 Chl. clathratiforme proteins in Lake Cadagno and quantitatively compared 621 of these in the four samples. Our results showed that compared with cells obtained from the photic zone, cells collected from the dark part of the water column had the same expression level of key enzymes involved in carbon metabolism and photosynthetic light harvesting. However, most proteins participating in nitrogen and sulfur metabolism were twofold less abundant in the dark. From the proteome analysis we were able to show that Chl. clathratiforme in the photic zone contains enzymes for fixation of N2 and the complete oxidation of sulfide to sulfate while these processes are probably not active in the dark. Instead we propose that Chl. clathratiforme cells in the dark part of the water column obtain energy for maintenance from the fermentation of polyglucose. Based on the observed protein compositions we have constructed possible pathways for C, N and S metabolism in Chl. clathratiforme.

Habicht, Kirsten Silvia; Miller, Mette

2011-01-01

57

Light-harvesting complexes from purple sulfur bacteria Allochromatium minutissimum assembled without carotenoids.  

Science.gov (United States)

Effect of carotenoid (Car) biosynthesis inhibitor diphenylamine (DPA) on purple sulfur bacteria Allochromatium (Alc) minutissimum cell growth has been investigated. Cell growth in the presence of maximum concentration of DPA results in practically complete suppression (?99%) of carotenoids (Cars) according to the spectrophotometric, HPLC and CD data. Phytoene does not replace the colored carotenoids in these cells. Also Phytoene does not accumulate in large amounts in the cells treated with DPA. A new method for calculating the content of Cars in the complexes from the cells with inhibited Car synthesis including the number of empty Car's "pockets" has been used. Our results together with published data devoted to DPA action on the cell growth of purple bacteria revealed that Phytoene was not accumulated in the cells treated with DPA. We have concluded that (i) DPA completely inhibits or strongly reduces synthesis of the colored Cars in the cells of purple bacteria, (ii) Phytoene is the main one among the trace amounts of the other Cars in the case of significant inhibition of Car biosynthesis (80-90% or higher). The amount of the LH2 complexes presented in the membranes of Alc minutissimum was found to be little dependent on DPA. From DPA-grown cultures it was possible to isolate Car-less both the LH1 (as LH1-RC complex) and the LH2 complexes. Electronic absorption properties of BChl's were very similar to those isolated from the control cells. It is shown by HPLC data that the 100 LH2 complexes from cells of Alc minutissimum, in which the synthesis of Car was depressed, contained ?9 Car molecules and 5 Phytoene molecules. Thus, only nine (with 1 Car molecule per a complex) or less (if more than one Car molecule per a complex) of the 100 LH2 complexes contain molecules of Cars. It means that 90 or more LH2 complexes from each 100 ones are assembled without any Cars. This is in strong contrast with the previous results obtained with purple non-sulfur bacterium Rhodobacter sphaeroides, where the amount of LH2 presented in the membrane was directly correlated to the amount of the carotenoids synthesized (H.P. Lang, C.N. Hunter, The relationship between carotenoid biosynthesis and the assembly of the light harvesting LH2 complex in Rhodobacter sphaeroides, Biochem. J. 298 (1994) 197-205). Our results show that although the presence of Car molecules is important for the stability of the LH2 complexes the overall native structure can be maintained without any Cars at least in the case of purple sulfur bacteria. PMID:22245415

Moskalenko, A A; Makhneva, Z K

2011-12-16

58

Light-harvesting complexes from purple sulfur bacteria Allochromatium minutissimum assembled without carotenoids.  

UK PubMed Central (United Kingdom)

Effect of carotenoid (Car) biosynthesis inhibitor diphenylamine (DPA) on purple sulfur bacteria Allochromatium (Alc) minutissimum cell growth has been investigated. Cell growth in the presence of maximum concentration of DPA results in practically complete suppression (?99%) of carotenoids (Cars) according to the spectrophotometric, HPLC and CD data. Phytoene does not replace the colored carotenoids in these cells. Also Phytoene does not accumulate in large amounts in the cells treated with DPA. A new method for calculating the content of Cars in the complexes from the cells with inhibited Car synthesis including the number of empty Car's "pockets" has been used. Our results together with published data devoted to DPA action on the cell growth of purple bacteria revealed that Phytoene was not accumulated in the cells treated with DPA. We have concluded that (i) DPA completely inhibits or strongly reduces synthesis of the colored Cars in the cells of purple bacteria, (ii) Phytoene is the main one among the trace amounts of the other Cars in the case of significant inhibition of Car biosynthesis (80-90% or higher). The amount of the LH2 complexes presented in the membranes of Alc minutissimum was found to be little dependent on DPA. From DPA-grown cultures it was possible to isolate Car-less both the LH1 (as LH1-RC complex) and the LH2 complexes. Electronic absorption properties of BChl's were very similar to those isolated from the control cells. It is shown by HPLC data that the 100 LH2 complexes from cells of Alc minutissimum, in which the synthesis of Car was depressed, contained ?9 Car molecules and 5 Phytoene molecules. Thus, only nine (with 1 Car molecule per a complex) or less (if more than one Car molecule per a complex) of the 100 LH2 complexes contain molecules of Cars. It means that 90 or more LH2 complexes from each 100 ones are assembled without any Cars. This is in strong contrast with the previous results obtained with purple non-sulfur bacterium Rhodobacter sphaeroides, where the amount of LH2 presented in the membrane was directly correlated to the amount of the carotenoids synthesized (H.P. Lang, C.N. Hunter, The relationship between carotenoid biosynthesis and the assembly of the light harvesting LH2 complex in Rhodobacter sphaeroides, Biochem. J. 298 (1994) 197-205). Our results show that although the presence of Car molecules is important for the stability of the LH2 complexes the overall native structure can be maintained without any Cars at least in the case of purple sulfur bacteria.

Moskalenko AA; Makhneva ZK

2012-03-01

59

Phototrophic purple sulfur bacteria as heat engines in the South Andros Black Hole.  

Science.gov (United States)

Photosynthetic organisms normally endeavor to optimize the efficiency of their light-harvesting apparatus. However, here we describe two bacterial isolates belonging to the genera Allochromatium and Thiocapsa that demonstrate a novel adaptation by optimizing their external growth conditions at the expense of photosynthetic efficiency. In the South Andros Black Hole, Bahamas, a dense l-m thick layer of these anoxygenic purple sulfur bacteria is present at a depth of 17.8 m. In this layer the water temperature increases sharply to 36 degrees C as a consequence of the low-energy transfer efficiency of their carotenoids (ca. 30%). These include spirilloxanthin, and related polyene molecules and a novel chiral carotenoid identified as spirilloxanthin-2-ol, not previously reported in purple bacteria. To our knowledge, this study presents the first evidence of such a bacterial mass significantly increasing the ambient water temperature. The transduction of light to heat energy to excess heat may provide these anoxygenic phototropic bacteria with a competitive advantage over non-thermotolerant species, which would account for their predominance within the microbial layer. PMID:17906940

Herbert, Rodney A; Gall, Andrew; Maoka, Takashi; Cogdell, Richard J; Robert, Bruno; Takaichi, Shinichi; Schwabe, Stephanie

2007-09-29

60

Selection of oleuropein-degrading lactic acid bacteria strains isolated from fermenting Moroccan green olives  

Digital Repository Infrastructure Vision for European Research (DRIVER)

A total of 177 strains of lactic acid bacteria (LAB) were isolated from early-stage Moroccan Picholine green olive fermentation, including Lactobacillus plantarum (44.63%), Lactobacillus pentosus (25.99%), Lactobacillus brevis (9.61%) and <...

Ghabbour, N.; Lamzira, Z.; Thonart, P.; Cidalia, P.; Markaoui, M.; Asehraou, A.

 
 
 
 
61

Removal of sediment and bacteria from water using green chemistry.  

UK PubMed Central (United Kingdom)

Although nearly all newly derived water purification methods have improved the water quality in developing countries, few have been accepted and maintained for long-term use. Field studies indicate that the most beneficial methods use indigenous resources, as they are both accessible and accepted by communities they help. In an effort to implement a material that will meet community needs, two fractions of mucilage gum were extracted from the Opuntia ficus-indica cactus and tested as flocculation agents against sediment and bacterial contamination. As diatomic ions are known to affect both mucilage and promote cell aggregation, CaCl(2) was studied in conjunction and compared with mucilage as a bacteria removal method. To evaluate performance, ion-rich waters that mimic natural water bodies were prepared. Column tests containing suspensions of the sediment kaolin exhibited particle flocculation and settling rates up to 13.2 cm/min with mucilage versus control settling rates of 0.5 cm/min. Bacillus cereus tests displayed flocculation and improved settling times with mucilage concentrations lower than 5 ppm and removal rates between 97 and 98% were observed for high bacteria concentration tests (>10(8) cells/ml). This natural material not only displays water purification abilities, but it is also affordable, renewable and readily available.

Buttice AL; Stroot JM; Lim DV; Stroot PG; Alcantar NA

2010-05-01

62

An overview of the bacteria and archaea involved in removal of inorganic and organic sulfur compounds from coal  

Energy Technology Data Exchange (ETDEWEB)

Of special importance for biohydrometallurgy are acidophilic chemolithotrophic bacteria from a number of different taxonomic groups, namely: the genera of [ital Thiobacillus] and [ital Leptospirillum], moderately thermophilic bacteria which were combined into the group [ital Sulfobacillus-Alicyclobacillus], and archaea of the genera [ital Sulfolobus, Acidianus, Metallosphaera], and [ital Sulfurococcus]. These bacteria are able to oxidize one or more of the following compounds Fe[sup 2+], S[sup 0] and sulfide minerals and to grow under extreme environmental conditions. Growth pH varies in the range from 1 to 5, growth temperature - from 2 to 90[degree]C. They can tolerate high concentration of metal ions. They possess a great physiological, biochemical and genetic variability. Some of them are important for removal of inorganic sulfur compounds from coals. Some types of coals and oils contain aromatic heterocyclic compounds with the C-S bond. Although a wide range of mostly heterotrophic and some chemolithotrophic bacteria, from bacteria and archaea to eucaryotes, participate in its transformation, only certain organisms have a unique capability of splitting this bond. They can remove organic sulfur-containing compounds from coal. The possibilities of application of bacteria in biological processing of coals are discussed. 74 refs., 2 figs., 5 tabs.

Karavaiko, G.I.; Lobyreva, L.B. (Russian Academy of Sciences, Moscow (Russian Federation). Inst. of Microbiology)

1994-11-01

63

Characterization of Corn Nitrogen Status with a Greenness Index under Different Availability of Sulfur  

UK PubMed Central (United Kingdom)

Several methodologies measure leaf greenness intensity and relate it to crop N status. There is no evidence, however, of the utility of this variable to detect N deficiencies in corn (Zea mays L.) under S deficiency. The objective of this work was to evaluate the potential of two indexes based on leaf greenness intensity to detect N deficiencies in corn under different levels of S. Two experiments at Balcarce, Argentina (Bce I and Bce II), and one at 9 de Julio, Argentina (9dJ), were conducted during the 2005-2006 and 2006-2007 seasons with different levels of N and S. Weekly measurements of greenness index (GI) were performed, and whole-plant samples were taken at four developmental stages to determine crop N and S accumulation. No N x S interaction was found in any measured variable. Nitrogen increased dry matter N and S accumulation, grain yield, and GI. Sulfur fertilization resulted in increased S accumulation in all experiments, and grain yield at Bce II and 9dJ. This nutrient also increased GI during several crop stages in all experiments. A nitrogen sufficiency index (NSI) was related to its relative yield (R2: 0.67, 0.63, 0.43, 0.67 for stages V5-V8, V9-V11, V13-V14, and V15-V18, respectively) under different S levels. On the other hand, a new index called relative greenness index (RGI), proposed for situations that could present S deficiencies, was also related to its relative yield (R2: 0.67, 0.81, 0.63, 0.82 for stages V5-V8, V9-V11, V13-V14, and V15-V18, respectively) under different S levels. The regression lines of both indexes were coincident for all sample dates. It was concluded that crop N status can be characterized under different levels of S through the NSI. Future research, however, should test these results under a wider range of S levels.

Pagani Agustín; Echeverría HernánE; Andrade FernandoH; Sainz Rozas HernánR

2009-03-01

64

Excitation energy flow in chlorosome antennas of green photosynthetic bacteria  

Energy Technology Data Exchange (ETDEWEB)

Energy flow in whole cells of the thermophilic green photosynthetic bacterium Chloroflexus aurantiacus was studied by measurements of time-resolved fluorescence spectra in the picosecond time range, detected by both streak camera and single-photon counting methods. These data characterize the energy-transfer sequence from bacteriochlorophyll c (BChl c), found in membrane-associated antenna structures called chlorosomes, to BChl a in the chlorosome baseplate, then to a BChl a antenna complex in the cytoplasmic membrane, and finally to the photochemical reaction center. Upon selective excitation of BChl c in chlorosomes, the decay time of the emission arising from BChl c was 16 ps. The apparent rise time of the emission from the baseplate pigment was < 3 ps. The time course of the transfer from the baseplate BChl a to the membrane-bound BChl a complex was clearly detected. A major 41-ps decay component of the baseplate BChl a emission corresponded to the rise term found for the membrane-bound BChl a emission. With a kinetic analysis, a model is proposed for the structure and function of the chlorosome antenna system in Chloroflexus aurantiacus. The data suggest that the excitation-transfer process may utilize a novel mechanism that takes advantage of the photophysical properties of aggregated pigments. BChl c molecules form naturally occurring aggregates with oligomeric structures similar to J aggregates, but very different from the organization of antenna pigment-proteins from other photosynthetic organisms. These oligomers absorb light and transfer excitations to a small amount of BChl a antenna proteins in the baseplate. The baseplate acts as an energy-transfer interface between the chlorosome and the antenna protein complexes located within the membrane. The integral membrane antenna complexes in turn deliver the excitations to the reaction center where photosynthesis is initiated by electron-transfer reactions.

Mimuro, Mamoru (National Institute for Basic Biology, Aichi (Japan)); Nozawa, Tsunenori (Tohoku Univ., Miyagi (Japan)); Tamai, Naoto; Yamazaki, Iwao (Institute for Molecular Science, Aichi (Japan)); Shimada, Keizou (Tokyo Metropolitan Univ. (Japan)); Lin, Su; Knox, R.S. (Univ. of Rochester, NY (USA)); Wittmershaus, B.P.; Brune, D.C.; Blankenship, R.E. (Arizona State Univ., Tempe (USA))

1989-10-19

65

Methods for removing malodorous sulfur compounds from pulp mill flue gases and the like by using green liquor  

Energy Technology Data Exchange (ETDEWEB)

This is an improved method for removing malodorous sulfur compounds from flue gases generated in kraft or sodium sulfite pulping operations and the like by the absorption process using green liquor, an aqueous solution containing sodium sulfide and sodium carbonate. The malodorous gas compounds, including hydrogen sulfide, methyl mercaptan, and dimethyl sulfide are preferentially absorbed by the sodium sulfide forming sodium hydrosulfide and methanol. Any sulfur dioxide in the gas is absorbed and neutralized by sodium carbonate. In this method carbon dioxide absorption is minimized and the formation of sodium bicarbonate is limited. Sodium bicarbonate formation is minimized in order to avoid its reaction with sodium hydrosulfide which would then release undesirable hydrogen sulfide during absorption, as well as to forestall the need to increase chemical and lime kiln capacity requirements when the green liquor returned to the kraft recovery process contains excess amounts of sodium bicarbonate.

Farin, W.G.

1984-02-14

66

Application of bacteria involved in the biological sulfur cycle for paper mill effluent purification  

International Nuclear Information System (INIS)

In anaerobic wastewater treatment, the occurrence of biological sulfate reduction results in the formation of unwanted hydrogen sulfide, which is odorous, corrosive and toxic. In this paper, the role and application of bacteria in anaerobic and aerobic sulfur transformations are described and exemplified for the treatment of a paper mill wastewater. The sulfate containing wastewater first passes an anaerobic UASB reactor for bulk COD removal which is accompanied by the formation of biogas and hydrogen sulfide. In an aeration pond, the residual CODorganic and the formed dissolved hydrogen sulfide are removed. The biogas, consisting of CH4 (80-90 vol.%), CO2 (10-20 vol.%) and H2S (0.8-1.2 vol.%), is desulfurised prior to its combustion in a power generator thereby using a new biological process for H2S removal. This process will be described in more detail in this paper. Biomass from the anaerobic bioreactor has a compact granular structure and contains a diverse microbial community. Therefore, other anaerobic bioreactors throughout the world are inoculated with biomass from this UASB reactor. The sludge was also successfully used in investigation on sulfate reduction with carbon monoxide as the electron donor and the conversion of methanethiol. This shows the biotechnological potential of this complex reactor biomass

2009-02-01

67

[Influence of transition metal compounds on superoxide dismutase activity of sulfur reducing Desulfuromonas acetoxidans bacteria].  

UK PubMed Central (United Kingdom)

Superoxide dismutase, as one of the enzymes of cells' antioxidant defensive system, catalyzes superoxide anion-radical (O2-) dismutation with O2 and H2O2 forming. The influence of such transition metal compounds, as FeSO4, FeCl3, MnCl2, NiCl2, and CoCl2 on superoxide dismutase activity of sulfur-reducing Desulfuromonas acetoxidans bacteria has been investigated. Maximal activity of the investigated enzyme has been observed accordingly under the influence of 1.0 mM of NiCl2, 2.0 mM of CoCl2 and MnCl2 on the second day and under the influence of 1.0 mM of FeCl3 and FeSO4 respectively, on the third day of growth in comparison with control samples. An increase of incubation time and concentration of metal compound in the medium caused the inhibition of superoxide dismutase activity.

Vasyliv OM; Hnatush SO

2013-03-01

68

Filamentous sulfur bacteria, Beggiatoa spp., in arctic marine sediments (Svalbard, 79°N)  

DEFF Research Database (Denmark)

Fjord sediments on the west coast of the arctic archipelago Svalbard were surveyed to understand whether large filamentous sulfur bacteria of the genus Beggiatoa thrive at seawater temperatures permanently near freezing. Two sediments had abundant populations of Beggiatoa, while at six sites, only sporadic occurrences were observed. We conclude that Beggiatoa, although previously unnoticed, are widespread in these arctic fjord sediments. Beggiatoa ranged in diameter from 2 to 52 ?m and, by those tested, stored nitrate in vacuoles at up to 260 mM. The 16S rRNA gene sequence of a 20-?m-wide filament is closely associated with other large, marine, nitrate-storing Beggiatoa. The Beggiatoa mostly occurred in the upper 2-5 cm of oxidized surface sediment between oxygen and the deeper sulfidic zone. In spite of a very low or an undetectable sulfide concentration, sulfate reduction provided abundant H2S in this zone. The total living biomass of Beggiatoa filaments at one study site varied over 3 years between 1.13 and 3.36 g m-2. Because of their large size, Beggiatoa accounted for up to 15% of the total prokaryotic biomass, even though the filament counts at this site were rather low, comprising <1/10 000 of the bacterial numbers on a cell basis.

JØrgensen, Bo Barker; Dunker, Rita

2010-01-01

69

Isolation of lactic acid bacteria for its possible use in the fermentation of green algerian olives  

Directory of Open Access Journals (Sweden)

Full Text Available This study was undertaken with the aim of obtaining lactic acid bacteria with the ability to ferment olives for possible use as starter cultures. For this reason, 32 isolates of lactic acid bacteria isolated from the spontaneous fermentation of green olives were characterized and identified on the basis of morphological and biochemical criteria. 14 of them were identified as Lactococcus lactis, 11 isolates as Lactobacillus plantarum and 7 isolates as Enterococcus sp. Of the 18 isolates examined for antagonistic activity, 3 isolates of Lactobacillus plantarum and one isolate of Enterococcus sp. were able to give distinct zones of inhibition against 5 indicator strains of lactic acid bacteria isolated in this study. Cell free supernatant of Lactobacillus plantarum OL9 was active against Gram-positive bacteria (Lactobacillus, Enterococcus and Propionibacterium) and also against one Gram-negative bacteria strain of spoilage significance (Erwinia).Este estudio se emprendió con el objetivo de obtener bacterias del ácido láctico con capacidad para utilizarse como cultivo iniciador en la fermentación de aceitunas. Por esta razón, 32 cepas de bacterias del ácido láctico procedentes de fermentaciones espontáneas de aceitunas verdes se caracterizaron e identificaron en función de criterios morfológicos y bioquímicos. Catorce cepas se identificaron como Lactococcus lactis, 11 cepas como Lactobacillus plantarum y 7 cepas como Enterococcus sp. De las 18 cepas que se examinaron para detectar actividades antagónicas, se encontró que 3 cepas de Lactobacillus plantarum y una de Enterococcus sp. mostraban zonas de inhibición contra 5 cepas indicadoras de bacterias del ácido láctico aisladas en este estudio. El sobrenadante libre de células Lactobacillus plantarum OL9 fue activo contra diversas bacterias Gram-positivas (Lactobacillus, Enterococcus y Propionibacterium) y contra una cepa de bacteria Gram-negativa relacionada con alteraciones (Erwinia).

Mourad, Kacem; Halima, Zadi-Karam; Nour-Eddine, Karam

2004-01-01

70

Roseobacter clade bacteria are abundant in coastal sediments and encode a novel combination of sulfur oxidation genes.  

Science.gov (United States)

Roseobacter clade bacteria (RCB) are abundant in marine bacterioplankton worldwide and central to pelagic sulfur cycling. Very little is known about their abundance and function in marine sediments. We investigated the abundance, diversity and sulfur oxidation potential of RCB in surface sediments of two tidal flats. Here, RCB accounted for up to 9.6% of all cells and exceeded abundances commonly known for pelagic RCB by 1000-fold as revealed by fluorescence in situ hybridization (FISH). Phylogenetic analysis of 16S rRNA and sulfate thiohydrolase (SoxB) genes indicated diverse, possibly sulfur-oxidizing RCB related to sequences known from bacterioplankton and marine biofilms. To investigate the sulfur oxidation potential of RCB in sediments in more detail, we analyzed a metagenomic fragment from a RCB. This fragment encoded the reverse dissimilatory sulfite reductase (rDSR) pathway, which was not yet found in RCB, a novel type of sulfite dehydrogenase (SoeABC) and the Sox multi-enzyme complex including the SoxCD subunits. This was unexpected as soxCD and dsr genes were presumed to be mutually exclusive in sulfur-oxidizing prokaryotes. This unique gene arrangement would allow a metabolic flexibility beyond known sulfur-oxidizing pathways. We confirmed the presence of dsrA by geneFISH in closely related RCB from an enrichment culture. Our results show that RCB are an integral part of the microbial community in marine sediments, where they possibly oxidize inorganic and organic sulfur compounds in oxic and suboxic sediment layers. PMID:22739490

Lenk, Sabine; Moraru, Cristina; Hahnke, Sarah; Arnds, Julia; Richter, Michael; Kube, Michael; Reinhardt, Richard; Brinkhoff, Thorsten; Harder, Jens; Amann, Rudolf; Mußmann, Marc

2012-06-28

71

Glycolytic breakdown of sulfoquinovose in bacteria: a missing link in the sulfur cycle.  

Science.gov (United States)

Sulfoquinovose (6-deoxy-6-sulfo-D-glucopyranose), formed by the hydrolysis of the plant sulfolipid, is a major component of the biological sulfur cycle. However, pathways for its catabolism are poorly delineated. We examined the hypothesis that mineralization of sulfoquinovose to inorganic sulfate is initiated by reactions of the glycolytic and/or Entner-Doudoroff pathways in bacteria. Metabolites of [U-(13)C]sulfoquinovose were identified by (13)C-nuclear magnetic resonance (NMR) in strains of Klebsiella and Agrobacterium previously isolated for their ability to utilize sulfoquinovose as a sole source of carbon and energy for growth, and cell extracts were analyzed for enzymes diagnostic for the respective pathways. Klebsiella sp. strain ABR11 grew rapidly on sulfoquinovose, with major accumulations of sulfopropandiol (2,3-dihydroxypropanesulfonate) but no detectable release of sulfate. Later, when sulfoquinovose was exhausted and growth was very slow, sulfopropandiol disappeared and inorganic sulfate and small amounts of sulfolactate (2-hydroxy-3-sulfopropionate) were formed. In Agrobacterium sp. strain ABR2, growth and sulfoquinovose disappearance were again coincident, though slower than that in Klebsiella sp. Release of sulfate was still late but was faster than that in Klebsiella sp., and no metabolites were detected by (13)C-NMR. Extracts of both strains grown on sulfoquinovose contained phosphofructokinase activities that remained unchanged when fructose 6-phosphate was replaced in the assay mixture with either glucose 6-phosphate or sulfoquinovose. The results were consistent with the operation of the Embden-Meyerhoff-Parnas (glycolysis) pathway for catabolism of sulfoquinovose. Extracts of Klebsiella but not Agrobacterium also contained an NAD(+)-dependent sulfoquinovose dehydrogenase activity, indicating that the Entner-Doudoroff pathway might also contribute to catabolism of sulfoquinovose. PMID:14602597

Roy, Alexander B; Hewlins, Michael J E; Ellis, Andrew J; Harwood, John L; White, Graham F

2003-11-01

72

Isotopically labeled sulfur compounds and synthetic selenium and tellurium analogues to study sulfur metabolism in marine bacteria  

Science.gov (United States)

Summary Members of the marine Roseobacter clade can degrade dimethylsulfoniopropionate (DMSP) via competing pathways releasing either methanethiol (MeSH) or dimethyl sulfide (DMS). Deuterium-labeled [2H6]DMSP and the synthetic DMSP analogue dimethyltelluriopropionate (DMTeP) were used in feeding experiments with the Roseobacter clade members Phaeobacter gallaeciensis DSM 17395 and Ruegeria pomeroyi DSS-3, and their volatile metabolites were analyzed by closed-loop stripping and solid-phase microextraction coupled to GC–MS. Feeding experiments with [2H6]DMSP resulted in the incorporation of a deuterium label into MeSH and DMS. Knockout of relevant genes from the known DMSP demethylation pathway to MeSH showed in both species a residual production of [2H3]MeSH, suggesting that a second demethylation pathway is active. The role of DMSP degradation pathways for MeSH and DMS formation was further investigated by using the synthetic analogue DMTeP as a probe in feeding experiments with the wild-type strain and knockout mutants. Feeding of DMTeP to the R. pomeroyi knockout mutant resulted in a diminished, but not abolished production of demethylation pathway products. These results further corroborated the proposed second demethylation activity in R. pomeroyi. Isotopically labeled [2H3]methionine and 34SO4 2?, synthesized from elemental 34S8, were tested to identify alternative sulfur sources besides DMSP for the MeSH production in P. gallaeciensis. Methionine proved to be a viable sulfur source for the MeSH volatiles, whereas incorporation of labeling from sulfate was not observed. Moreover, the utilization of selenite and selenate salts by marine alphaproteobacteria for the production of methylated selenium volatiles was explored and resulted in the production of numerous methaneselenol-derived volatiles via reduction and methylation. The pathway of selenate/selenite reduction, however, proved to be strictly separated from sulfate reduction.

Brock, Nelson L; Citron, Christian A; Zell, Claudia; Berger, Martine; Wagner-Dobler, Irene; Petersen, Jorn; Brinkhoff, Thorsten; Simon, Meinhard

2013-01-01

73

Isotopically labeled sulfur compounds and synthetic selenium and tellurium analogues to study sulfur metabolism in marine bacteria.  

Science.gov (United States)

Members of the marine Roseobacter clade can degrade dimethylsulfoniopropionate (DMSP) via competing pathways releasing either methanethiol (MeSH) or dimethyl sulfide (DMS). Deuterium-labeled [(2)H6]DMSP and the synthetic DMSP analogue dimethyltelluriopropionate (DMTeP) were used in feeding experiments with the Roseobacter clade members Phaeobacter gallaeciensis DSM 17395 and Ruegeria pomeroyi DSS-3, and their volatile metabolites were analyzed by closed-loop stripping and solid-phase microextraction coupled to GC-MS. Feeding experiments with [(2)H6]DMSP resulted in the incorporation of a deuterium label into MeSH and DMS. Knockout of relevant genes from the known DMSP demethylation pathway to MeSH showed in both species a residual production of [(2)H3]MeSH, suggesting that a second demethylation pathway is active. The role of DMSP degradation pathways for MeSH and DMS formation was further investigated by using the synthetic analogue DMTeP as a probe in feeding experiments with the wild-type strain and knockout mutants. Feeding of DMTeP to the R. pomeroyi knockout mutant resulted in a diminished, but not abolished production of demethylation pathway products. These results further corroborated the proposed second demethylation activity in R. pomeroyi. Isotopically labeled [(2)H3]methionine and (34)SO4 (2-), synthesized from elemental (34)S8, were tested to identify alternative sulfur sources besides DMSP for the MeSH production in P. gallaeciensis. Methionine proved to be a viable sulfur source for the MeSH volatiles, whereas incorporation of labeling from sulfate was not observed. Moreover, the utilization of selenite and selenate salts by marine alphaproteobacteria for the production of methylated selenium volatiles was explored and resulted in the production of numerous methaneselenol-derived volatiles via reduction and methylation. The pathway of selenate/selenite reduction, however, proved to be strictly separated from sulfate reduction. PMID:23766810

Brock, Nelson L; Citron, Christian A; Zell, Claudia; Berger, Martine; Wagner-Döbler, Irene; Petersen, Jörn; Brinkhoff, Thorsten; Simon, Meinhard; Dickschat, Jeroen S

2013-05-15

74

Isotopically labeled sulfur compounds and synthetic selenium and tellurium analogues to study sulfur metabolism in marine bacteria.  

UK PubMed Central (United Kingdom)

Members of the marine Roseobacter clade can degrade dimethylsulfoniopropionate (DMSP) via competing pathways releasing either methanethiol (MeSH) or dimethyl sulfide (DMS). Deuterium-labeled [(2)H6]DMSP and the synthetic DMSP analogue dimethyltelluriopropionate (DMTeP) were used in feeding experiments with the Roseobacter clade members Phaeobacter gallaeciensis DSM 17395 and Ruegeria pomeroyi DSS-3, and their volatile metabolites were analyzed by closed-loop stripping and solid-phase microextraction coupled to GC-MS. Feeding experiments with [(2)H6]DMSP resulted in the incorporation of a deuterium label into MeSH and DMS. Knockout of relevant genes from the known DMSP demethylation pathway to MeSH showed in both species a residual production of [(2)H3]MeSH, suggesting that a second demethylation pathway is active. The role of DMSP degradation pathways for MeSH and DMS formation was further investigated by using the synthetic analogue DMTeP as a probe in feeding experiments with the wild-type strain and knockout mutants. Feeding of DMTeP to the R. pomeroyi knockout mutant resulted in a diminished, but not abolished production of demethylation pathway products. These results further corroborated the proposed second demethylation activity in R. pomeroyi. Isotopically labeled [(2)H3]methionine and (34)SO4 (2-), synthesized from elemental (34)S8, were tested to identify alternative sulfur sources besides DMSP for the MeSH production in P. gallaeciensis. Methionine proved to be a viable sulfur source for the MeSH volatiles, whereas incorporation of labeling from sulfate was not observed. Moreover, the utilization of selenite and selenate salts by marine alphaproteobacteria for the production of methylated selenium volatiles was explored and resulted in the production of numerous methaneselenol-derived volatiles via reduction and methylation. The pathway of selenate/selenite reduction, however, proved to be strictly separated from sulfate reduction.

Brock NL; Citron CA; Zell C; Berger M; Wagner-Döbler I; Petersen J; Brinkhoff T; Simon M; Dickschat JS

2013-01-01

75

Metabolic adaptation and trophic strategies of soil bacteria--C1- metabolism and sulfur chemolithotrophy in Starkeya novella  

Science.gov (United States)

The highly diverse and metabolically versatile microbial communities found in soil environments are major contributors to the global carbon, nitrogen, and sulfur cycles. We have used a combination of genome –based pathway analysis with proteomics and gene expression studies to investigate metabolic adaptation in a representative of these bacteria, Starkeya novella, which was originally isolated from agricultural soil. This bacterium was the first facultative sulfur chemolithoautotroph that was isolated and it is also able to grow with methanol and on over 39 substrates as a heterotroph. However, using glucose, fructose, methanol, thiosulfate as well as combinations of the carbon compounds with thiosulfate as growth substrates we have demonstrated here that contrary to the previous classification, S. novella is not a facultative sulfur chemolitho- and methylotroph, as the enzyme systems required for these two growth modes are always expressed at high levels. This is typical for key metabolic pathways. In addition enzymes for various pathways of carbon dioxide fixation were always expressed at high levels, even during heterotrophic growth on glucose or fructose, which suggests a role for these pathways beyond the generation of reduced carbon units for cell growth, possibly in redox balancing of metabolism. Our results then indicate that S. novella, a representative of the Xanthobacteraceae family of methylotrophic soil and freshwater dwelling bacteria, employs a mixotrophic growth strategy under all conditions tested here. As a result the contribution of this bacterium to either carbon sequestration or the release of climate active substances could vary very quickly, which has direct implications for the modeling of such processes if mixotrophy proves to be the main growth strategy for large populations of soil bacteria.

Kappler, Ulrike; Nouwens, Amanda S.

2013-01-01

76

Bacteria morphology and diversity of the combined autotrophic nitritation and sulfur-carbon three-dimensional-electrode denitrification process.  

Science.gov (United States)

The bacterial morphology and diversity in the reactors of a combined autotrophic nitritation and sulfur-carbon three-dimensional-electrode denitrification (CANSCTED) process operating under steady-state conditions were investigated by scanning electron microscopy and partial 16S rDNA cloning and sequencing. The CANSCTED process consisted of two parts, i.e., the nitritation membrane bioreactor (NMBR) and the sulfur-carbon three-dimensional-electrode denitrification reactor (SCTED). When the influent NH(+) 4 concentration of NMBR ranged from 854 to 1086 mg N L(-1), with about 50% NH(+) 4 removal efficiency and NO(-) 2 accumulation rate, the spherical and spheroidal ammonia-oxidizing bacteria were predominant, with community successions of ?-Proteobacteria (60.0%), Bacteroidetes (28.3%) and Chloroflexi (11.7%). The NMBR effluent with 429?543 mg N L(-1) NH(+) 4 and 519?578 mg N L(-1) NO(-) 2 was continuously supplied to SCTED for sulfur denitrification, bioelectrochemical hydrogen denitrification, and anaerobic ammonium oxidation. The predominant bacterial community successions were ?-Proteobacteria (78.3%) and ?-Proteobacteria (21.7%). When the SCTED influent was supplied with only NO(-) 2 (412-525 mg N L(-1)) as nitrogen substrate, the predominant bacteria in SCTED were short-bacilliform and spheroidal denitrification bacteria, ?-Proteobacteria (82.0%), ?-Proteobacteria (16.4%) and ?-Proteobacteria (1.6%). Although the predominant bacterial communities were both ?-Proteobacteria and ?-Proteobacteria in SCTED, the species and quantity of each community varied with the change of SCTED influent composition, which indicated that the composition influence the bacterial morphology and diversity in SCTED. PMID:24117082

Wang, Haiyan; Zhou, Yuexi; Yuan, Quan; Zhao, Hua; Dai, Xin

2014-01-01

77

Bacteria morphology and diversity of the combined autotrophic nitritation and sulfur-carbon three-dimensional-electrode denitrification process.  

UK PubMed Central (United Kingdom)

The bacterial morphology and diversity in the reactors of a combined autotrophic nitritation and sulfur-carbon three-dimensional-electrode denitrification (CANSCTED) process operating under steady-state conditions were investigated by scanning electron microscopy and partial 16S rDNA cloning and sequencing. The CANSCTED process consisted of two parts, i.e., the nitritation membrane bioreactor (NMBR) and the sulfur-carbon three-dimensional-electrode denitrification reactor (SCTED). When the influent NH(+) 4 concentration of NMBR ranged from 854 to 1086 mg N L(-1), with about 50% NH(+) 4 removal efficiency and NO(-) 2 accumulation rate, the spherical and spheroidal ammonia-oxidizing bacteria were predominant, with community successions of ?-Proteobacteria (60.0%), Bacteroidetes (28.3%) and Chloroflexi (11.7%). The NMBR effluent with 429?543 mg N L(-1) NH(+) 4 and 519?578 mg N L(-1) NO(-) 2 was continuously supplied to SCTED for sulfur denitrification, bioelectrochemical hydrogen denitrification, and anaerobic ammonium oxidation. The predominant bacterial community successions were ?-Proteobacteria (78.3%) and ?-Proteobacteria (21.7%). When the SCTED influent was supplied with only NO(-) 2 (412-525 mg N L(-1)) as nitrogen substrate, the predominant bacteria in SCTED were short-bacilliform and spheroidal denitrification bacteria, ?-Proteobacteria (82.0%), ?-Proteobacteria (16.4%) and ?-Proteobacteria (1.6%). Although the predominant bacterial communities were both ?-Proteobacteria and ?-Proteobacteria in SCTED, the species and quantity of each community varied with the change of SCTED influent composition, which indicated that the composition influence the bacterial morphology and diversity in SCTED.

Wang H; Zhou Y; Yuan Q; Zhao H; Dai X

2014-01-01

78

Absorption and dichroism spectra of cylindrical J aggregates and chlorosomes of green bacteria  

Energy Technology Data Exchange (ETDEWEB)

We study the absorption and linear and circular dichroism spectra of molecular aggregates having the shape of a cylinder. Examples are the chlorosomes of green bacteria and recently synthesized cyanine J aggregates, called amphi-pipes. We use a Frenkel exciton model and exploit the cylinder symmetry to separate the exciton states into bands with different transverse wavenumbers. Only three of these bands are optically active. The delicate interference between the contributions of these three bands to the CD spectrum, make this spectrum very sensitive to system parameters, such as the cylinder length. This offers a natural explanation for the observed strong variation of the CD spectra of chlorosomes with sample preparation technique.

Didraga, Catalin; Knoester, Jasper E-mail: knoester@phys.rug.nl

2003-05-01

79

[On the efficiency of energy migration from chlorosoma to the main bacteriochlorophyll in green bacteria].  

Science.gov (United States)

It is shown that the results provided in a variety of publications, which deal with structural characterization of green bacteria chlorosoma, are in explicit contradiction with kinetic and energy characteristics of microorganisms studied. The data on chlorosoma structure and composition represent no explanation as to how the additional quantity of electronic excitations generated by light in its dominating pigment C750 feeds the main photosystem.. In order to reveal the contradictions, the structural and spectral data on chlorosoma are analyzed in cooperation with the theory of inductive resonance developed by T. Ferster. PMID:22594279

Borisov, A Iu

80

Selection of oleuropein-degrading lactic acid bacteria strains isolated from fermenting Moroccan green olives  

Energy Technology Data Exchange (ETDEWEB)

A total of 177 strains of lactic acid bacteria (LAB) were isolated from early-stage Moroccan Picholine green olive fermentation, including Lactobacillus plantarum (44.63%), Lactobacillus pentosus (25.99%), Lactobacillus brevis (9.61%) and Pediococcus pentosaceus (19.77%). All the isolates were screened for their tolerance to olive leaf extract and oleuropein. Most of the isolates (85.3%) were found able to degrade oleuropein, when evaluated by either oleuropein or 5-Bromo-4-chloro-3-indolyl {beta}-D-glucuronide (X-Gluc) as substrates. The biodegradation capacity of the selected strains of each species was confirmed by HPLC analysis. (Author).

Ghabbour, N.; Lamzira, Z.; Thonart, P.; Cidalia, P.; Markaouid, M.; Asehraoua, A.

2011-07-01

 
 
 
 
81

Selection of oleuropein-degrading lactic acid bacteria strains isolated from fermenting Moroccan green olives  

International Nuclear Information System (INIS)

[en] A total of 177 strains of lactic acid bacteria (LAB) were isolated from early-stage Moroccan Picholine green olive fermentation, including Lactobacillus plantarum (44.63%), Lactobacillus pentosus (25.99%), Lactobacillus brevis (9.61%) and Pediococcus pentosaceus (19.77%). All the isolates were screened for their tolerance to olive leaf extract and oleuropein. Most of the isolates (85.3%) were found able to degrade oleuropein, when evaluated by either oleuropein or 5-Bromo-4-chloro-3-indolyl ?-D-glucuronide (X-Gluc) as substrates. The biodegradation capacity of the selected strains of each species was confirmed by HPLC analysis. (Author).

2011-01-01

82

Sulfur isotopic studies of Archean slate and graywacke from northern Minnesota: evidence for the existence of sulfate reducing bacteria  

International Nuclear Information System (INIS)

[en] Sulfur isotopic studies of pyrite from metasediments in the >2.6 Byr old Deer Lake greenstone sequence, Minnesota, have been conducted in order to evaluate the possible importance of sulfate reducing bacteria in sulfide formation. Delta34S values of pyrite from the Deer Lake sediments range from -2.3 to 11.01%, with a peak at of the order of + 0.02%. Isotopic data are consistent with either high temperature inorganic reduction of circulating seawater sulfate, or low temperature bacterial reduction. However, the lack of sulfide bands or massive occurrences in the sediments, the restriction of pyrite mineralization to the sediments, and the absence of evidence for hot spring activity suggest that a diagenetic origin of pyrite is more feasible. Sulfide in such an environment would be produced principally by the action of sulfate reducing bacteria. (author)

1981-01-01

83

Pressure-induced red shift and broadening of the Qy absorption of main light-harvesting antennae chlorosomes from green photosynthetic bacteria and their dependency upon alkyl substituents of the composite bacteriochlorophylls.  

UK PubMed Central (United Kingdom)

When pressure was applied to the main light-harvesting apparatus (chlorosomes) isolated from several green photosynthetic bacteria (up to 128 MPa), the Qy-absorption band in an aqueous solution was shifted to longer wavelengths. The shift, deltav, was completely reversible for (de)compression and also showed a linear relation as a function of the applied pressure. The pressure-sensitivity in the deltav was dependent upon the bacterial species. The pressure coefficient, deltav/deltaP, was -565 to -535 cm(-1) GPa(-1) for the chlorosomes from several green sulfur bacteria (Chlorobium species), which have several bacteriochlorophyll(BChl) homologues at the 8- and 12-positions as the antenna pigments. In contrast, a smaller value (-445 cm(-1) GPa(-1)) was estimated for the chlorosomes from the green nonsulfur bacterium (Chloroflexus aurantiacus), which has a single homologue with 8-ethyl and 12-methyl groups. These results were confirmed by the similar pressure dependency of in vitro self-aggregates of isolated BChls-c having various alkyl substituents at the 8- and 12-positions. The present pressurization study enables us to discuss a physiological meaning of a variety of antenna pigments in green photosynthetic bacteria.

Mizoguchi T; Kim TY; Sawamura S; Tamiaki H

2008-12-01

84

[Model of aggregation of pigments in the chlorosomal antenna of the green bacteria Chloroflexus aurantiacus  

UK PubMed Central (United Kingdom)

Independent experimental and theoretical evaluation was performed for the adequacy of our previously proposed general molecular model of structural organization of light-harvesting pigments in chlorosomal bacteriochlorophyll (BChl) c/d/e-containing superantenna of different green bacteria. Simultaneous measurement of hole burning in the optical spectra of chlorosomal BChl c and temperature dependence of steady-state fluorescence spectra of BChl c was accomplished in intact cells of photosynthetic green bacterium Chloroflexus aurantiacus; this allows unambiguous determination of the structure of exciton levels of BChl c oligomers in this natural antenna, which is a fundamental criterion for adequacy of any molecular model for in vivo aggregation of antenna pigments. Experimental data were shown to confirm our model of organization of oligometric pigments in chlorosomal BChl c antenna of green bacterium Chloroflexus aurantiacus. This model, which is based on experimental data and our theory of spectroscopy of oligomeric pigments, implies that the unit building block of BChl c antenna is a cylindrical assembly containing six excitonically coupled linear pigment chains whose exciton structure with intense upper levels provides for the optimal spectral properties of the light-harvesting antenna.

Mauring K; Novoderezhkin VI; Taisova AS; Fetisova ZG

2004-03-01

85

Abundance and diversity of organohalide-respiring bacteria in lake sediments across a geographical sulfur gradient.  

Science.gov (United States)

Across the U.S. Upper Midwest, a natural geographical sulfate gradient exists in lakes. Sediment grab samples and cores were taken to explore whether this sulfur gradient impacted organohalide-respiring Chloroflexi in lake sediments. Putative organohalide-respiring Chloroflexi were detected in 67 of 68 samples by quantitative polymerase chain reaction. Their quantities ranged from 3.5 × 10(4) to 8.4 × 10(10) copies 16S rRNA genes g(-1) dry sediment and increased in number from west to east, whereas lake sulfate concentrations decreased along this west-to-east transect. A terminal restriction fragment length polymorphism (TRFLP) method was used to corroborate this inverse relationship, with sediment samples from lower sulfate lakes containing both a higher number of terminal restriction fragments (TRFs) belonging to the organohalide-respiring Dehalococcoidetes, and a greater percentage of the TRFLP amplification made up by Dehalococcoidetes members. Statistical analyses showed that dissolved sulfur in the porewater, measured as sulfate after oxidation, appeared to have a negative impact on the total number of putative organohalide-respiring Chloroflexi, the number of Dehalococcoidetes TRFs, and the percentage of the TRFLP amplification made up by Dehalococcoidetes. These findings point to dissolved sulfur, presumably present as reduced sulfur species, as a potentially controlling factor in the natural cycling of chlorine, and perhaps as a result, the natural cycling of some carbon as well. PMID:23240654

Krzmarzick, Mark J; McNamara, Patrick J; Crary, Benjamin B; Novak, Paige J

2013-01-10

86

Transient electron paramagnetic resonance spectroscopy on green-sulfur bacteria and heliobacteria at two microwave frequencies.  

UK PubMed Central (United Kingdom)

Spin polarized transient EPR spectra taken at X-band (9 GHz) and K-band (24 GHz) of membrane fragments of Chlorobium tepidum and Heliobacillus mobilis are presented along with the spectra of two fractions obtained in the purification of reaction centers (RC) from C. tepidum. The lifetime of P+. is determined by measuring the decay of the EPR signals following relaxation of the initial spin polarization. All samples except one of the RC fractions show evidence of light induced charge separation and formation of chlorophyll triplet states. The lifetime of P+. is found to be biexponential with components of 1.5 ms and 30 ms for C. tepidum and 1.0 and 4.5 ms for Hc. mobilis at 100 K. In both cases, the rates are assigned to recombination from F-X. The spin polarized radical pair spectra for both species are similar and those from Hc. mobilis at room temperature and 100 K are identical. In all cases, an emission/absorption polarization pattern with a net absorption is observed. A slight narrowing of the spectra and a larger absorptive net polarization is found at K-band. No out-of-phase echo modulation is observed. Taken together, the recombination kinetics, the frequency dependence of the spin polarization and the absence of an out-of-phase echo signal lead to the assignment of the spectra to the contribution from P+. to the state P+.F-X. The origin of the net polarization and its frequency dependence are discussed in terms of singlet-triplet mixing in the precursor. It is shown that the field-dependent polarization expected to develop during the 600-700 ps lifetime of P+.A-.0 is in qualitative agreement with the observed spectra. The identity that the acceptor preceding FX and the conflicting evidence from EPR, optical methods and chemical analyses of the samples are discussed.

van der Est A; Hager-Braun C; Leibl W; Hauska G; Stehlik D

1998-12-01

87

Theoretical characterization of excitation energy transfer in chlorosome light-harvesting antennae from green sulfur bacteria  

CERN Document Server

Chlorosomes are the largest and most efficient natural light-harvesting antenna systems. They contain thousands of pigment molecules - bacteriochlorophylls (BChls)- that are organized into supramolecular aggregates and form a very efficient network for excitonic energy migration. Here, we present a theoretical study of excitation energy transfer (EET) in the chlorosome based on experimental evidence of the molecular assembly. Our model for the exciton dynamics throughout the antenna combines a stochastic time propagation of the excitonic wave function with molecular dynamics simulations of supramolecular structure, and electronic structure calculations of the excited states. The simulation results reveal a detailed picture of the EET in the chlorosome. Coherent energy transfer is significant only for the first 50 fs after the initial excitation, and the wavelike motion of the exciton is completely damped at 100 fs. Characteristic time constants of incoherent energy transfer, subsequently, vary from 1 ps to se...

Fujita, Takatoshi; Saikin, Semion K; Brookes, Jennifer C; Aspuru-Guzik, Alan

2013-01-01

88

Memory-assisted exciton diffusion in the chlorosome light-harvesting antenna of green sulfur bacteria  

CERN Document Server

Chlorosomes are likely the largest and most efficient natural light-harvesting photosynthetic antenna systems. They are composed of large numbers of bacteriochlorophylls organized into supramolecular aggregates. We explore the microscopic origin of the fast excitation energy transfer in the chlorosome using the recently-resolved structure and atomistic-detail simulations. Despite the dynamical disorder effects on the electronic transitions of the bacteriochlorophylls, our simulations show that the exciton delocalizes over the entire aggregate in about 200 fs. The memory effects associated to the dynamical disorder assist the exciton diffusion through the aggregates and enhance the diffusion coefficients as a factor of two as compared to the model without memory. Furthermore, exciton diffusion in the chlorosome is found to be highly anisotropic with the preferential transfer towards the baseplate, which is the next functional element in the photosynthetic system.

Fujita, Takatoshi; Saikin, Semion K; Aspuru-Guzik, Alan

2012-01-01

89

Retreived bacteria from Noctiluca miliaris (green) bloom of the northeastern Arabian Sea  

Science.gov (United States)

In recent years, seasonal blooms of the dinoflagellate Noctiluca miliaris have appeared in the open-waters of the northern Arabian Sea (NAS). This study provides the first characterization of bacteria from a seasonal bloom of green Noctiluca of NAS (20°N-17°N and 64°E-70°E), during the spring-inter-monsoon cruise of Sagar Sampada 253, in March 2007. Bacterial growth as assessed by most-probable number (MPN) and plate counts, revealed `variable-physiotypes' over a wide range of salinities (0%-25% w/v NaCl), pH levels (5-8.5), and organic nutrient strengths, in comparison to non-bloom waters. MPN indices of bacteria in surface waters of bloom stations *DWK and *PRB, corresponded to (3.08-4.41)×103 cells/mL at 3.5% NaCl (w/v), and (2.82-9.49)×102 cells/mL at 25% (w/v) NaCl in tryptone-yeast extract broth (TYE). Plate counts were (1.12-4)×106 CFU/mL at 0% (w/v) NaCl, (1.28-3.9)×106 CFU/mL at 3.5% (w/v) NaCl, and (0.4-7)×104 CFU/mL at 25% NaCl (w/v) on TYE. One-tenth-strength Zobell's gave (0.6-3.74)×105 CFU/mL at pH 5 to (3.58-7.5)×105 CFU/mL at pH 8.5. These bacteria were identified to the genera Bacillus, Cellulomonas, Staphylococcus, Planococcus, Dietzia, Virgibacillus, Micrococcus, Sporosarcinae, Leucobacter, and Halomonas. The identity of three strains (GUFBSS253N2, GUFBSS253N30, and GUFBSS253N84) was confirmed through 16S rDNA sequence homology as Bacillus cohnii, Bacillus flexus, and Bacillus cereus. The ˜2-3-fold higher plate counts of culturable bacteria from the open-waters of the NAS indicate that these bacteria could critically determine the biogeochemical dynamics of the bloom and its milieu. The role of these bacteria in sustaining/terminating the bloom is under evaluation.

Basu, Subhajit; Matondkar, S. G. Prabhu; Furtado, Irene

2013-01-01

90

Artificial photosynthesis modeled on green bacteria; Ryokushoku kogosei saikin wo moderu toshita jinko kogoseikei no sosei  

Energy Technology Data Exchange (ETDEWEB)

An artificial antenna system formed by novel synthetic zinc-chlorins was prepared as a model of extramembranous light-harvesting apparatus of photosynthetic green bacteria. Self-aggregates of the model compounds in aqueous solution of several surfactant and in non-polar organic solvents gave similar supramolecular structures with natural antennae, indicating that peptides are not important for construction of the antenna core part. Energy transfer from the self-aggregates to a bacteriochlorin was observed, which mimicked function of natural antennae, i. e., energy migrating from bacteriochlorophyll-c aggregates to bacteriochlorophyll-a. Elucidation of the supramolecular structure revealed that order self-assembly is necessary for ultra-fast and highly efficient energy transfer in the photosynthetic antennae. (author)

Tamiaki, Hitoshi [Ritsumeikan University, Kyoto (Japan). Dept. of Bioscience and Biotechnology

1999-12-16

91

Structure, Function, and Regulation of Antenna Complexes of Green Photosynthetic Bacteria; FINAL  

International Nuclear Information System (INIS)

This project is concerned with the structure and function of the chlorosome antennas found in green photosynthetic bacteria. Chlorosomes are ellipsoidal structures attached to the cytoplasmic side of the inner cell membrane. These antenna complexes provide a very large absorption cross section for light capture. Evidence is overwhelming that the chlorosome represents a very different type of antenna from that found in any other photosynthetic system yet studied. It is now clear that chlorosomes do not contain traditional pigment-proteins, in which the pigments bind to specific sites on proteins. Instead, the chlorosome pigments are organized in vivo into pigment oligomers in which direct pigment-pigment interactions are of dominant importance. Our group has used a multidisciplinary approach to investigate this unique system, including model systems, ultrafast spectroscopy, molecular biology, protein chemistry and X-ray crystallography.

2001-01-01

92

Isolation of Sulfur Reducing and Oxidizing Bacteria Found in Contaminated Drywall  

Directory of Open Access Journals (Sweden)

Full Text Available Drywall from China has been reported to release sulfur producing products which are corrosive to metals, result in noxious odors, and represent a significant health risk. It has been reported that these emissions produce medical symptoms such as respiratory or asthma type problems, sinusitis, gastrointestinal disorders, and vision problems in home owners and their household pets. We report here a method of identifying a causative agent for these emissions by sampling affected gypsum wallboard and subjecting those samples to Real Time Polymerase Chain Reaction [RT-PCR] studies. Specific DNA probes and primers have been designed and patented that detect a specific iron and sulfur reducing bacterium (i.e., Thiobacillus ferrooxidans). One hundred percent of affected drywall samples obtained from homes located in the southeastern United States tested positive for the presence of T. ferrooxidans. All negative controls consisting of unaffected wallboard and internal controls, Geotrichum sp., tested negative within our limits of detection.

Dennis G. Hooper; John Shane; David C. Straus; Kaye H. Kilburn; Vincent Bolton; John S. Sutton; Frederick T. Guilford

2010-01-01

93

Characterization of lactic acid bacteria from naturally-fermented Manzanilla Aloreña green table olives.  

Science.gov (United States)

Manzanilla Aloreña (or Aloreña) table olives are naturally fermented traditional green olives with a denomination of protection (DOP). The aim of this study was to search for lactic acid bacteria (LAB) with technological properties of interest for possible inclusion in a starter or protective culture preparation or also as probiotics. A collection of 144 LAB obtained from Aloreña green table olives naturally-fermented by four small-medium enterprises (SMEs) from Málaga (Spain), including lactobacilli (81.94%), leuconostocs (10.42%) and pediococci (7.64%) were studied. REP-PCR clustering and further identification of strains by sequencing of phes and rpo genes revealed that all lactobacilli from the different SMEs were Lactobacillus pentosus. Pediococci were identified as Pediococcus parvulus (SME1) and leuconostocs as Leuconostoc pseudomesenteroides (SME1 and SME4). Genotyping revealed that strains were not clonally related and exhibited a considerable degree of genomic diversity specially for lactobacilli and also for leuconostocs. Some strains exhibit useful technological properties such as production of antimicrobial substances active against pathogenic bacteria such as Listeria monocytogenes, Bacillus cereus, Staphylococcus aureus, Streptococcus mutans and Salmonella enterica, utilization of raffinose and stachyose, production of bile salt hydrolase, phytase and haeme-dependent catalase activities, growth at 10 °C and in the presence of 6.5% NaCl, good acidifying capacity and also resistance to freezing. However, none of the isolates showed protease or amylase activity, and also did not exhibit biogenic amine production from histidine, ornithine, cysteine or tyrosine. On the basis of data obtained, selected strains with potential traits were tested for their survival at low pH and their tolerance to bile salts, and the survival capacity demonstrated by some of the analysed strains are encouraging to further study their potential as probiotics. PMID:22986194

Abriouel, Hikmate; Benomar, Nabil; Cobo, Antonio; Caballero, Natacha; Fernández Fuentes, Miguel Ángel; Pérez-Pulido, Rubén; Gálvez, Antonio

2012-07-31

94

Sulfur biogeochemistry of cold seeps in the Green Canyon region of the Gulf of Mexico  

Science.gov (United States)

Cold seeps in the Gulf of Mexico provide a natural laboratory to study biogeochemical cycling of sulfur, carbon, and oxygen at hydrate- and hydrocarbon-rich deep marine settings with obvious additional relevance to studies of diverse modern and ancient seeps. Of particular interest are the sulfur isotope signatures of microbial sulfate reduction coupled to anaerobic oxidation of methane and other non-methane liquid and gaseous hydrocarbons. Whereas most of the published sulfur isotope data from cold seep systems pertain to pore-water species, our study integrates both solid and dissolved sulfur: acid-volatile sulfides (SAVS), pyrite (Spy), elemental sulfur (S°), dissolved sulfate and ?H2S. Modeled and 35SO42- reduction rates and ?13C and ?18O data for authigenic carbonates are integrated within this sulfur framework. Our results indicate extreme variability over narrow spatial and temporal scales within short distances (meters) from active seeps. High rates of microbial sulfate reduction can lead to complete consumption of the sulfate within the upper few centimeters of burial, while meters away the sulfate profile shows little depletion. Such small-scale variability must reflect the structure and temporal dynamics of hydrocarbon migration in the presence of low amounts of background organic matter. Our past work demonstrated that electron donors other than methane drive significant levels of microbial activity at these seeps, and very recent work has demonstrated that oxidation of higher chain volatile hydrocarbons can contribute to the high levels of microbial activity. These findings are consistent with our new results. Elevated concentrations of pyrite and diagenetic carbonate relative to background sediments are diagnostic of active seepage, yet the S isotopes tell more complex stories. Low levels of the transient, 'instantaneous' products of S cycling—AVS and S°—show high ?34S values that increase with depth. Most of the pyrite formation, however, seems to be very early as limited by the availability of reactive Fe phases. As such, ?34S values for pyrite at ancient seeps can show consistently low ?34S values that undersell the full intensity of microbial sulfate reduction. Low sedimentation rates, and the resulting low detrital iron fluxes, may in fact limit our ability to recognize seeps in the geologic record using only ?34S compositions for pyrite.

Formolo, Michael J.; Lyons, Timothy W.

2013-10-01

95

Antibiotic Resistant Bacteria As Bio-Indicator Of Polluted Effluent In The Green Turtles, Chelonia Mydas In Oman  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Abstract Antibiotic resistant bacteria were studied as bio-indicators of marine polluted effluents during egg-laying in green turtles. A non-invasive procedure for sampling oviductal fluid was used to test for exposure of turtles to pollution in Ras Al-Hadd, Oman, which is one of the most im...

96

Selection of oleuropein-degrading lactic acid bacteria strains isolated from fermenting Moroccan green olives  

Directory of Open Access Journals (Sweden)

Full Text Available A total of 177 strains of lactic acid bacteria (LAB) were isolated from early-stage Moroccan Picholine green olive fermentation, including Lactobacillus plantarum (44.63%), Lactobacillus pentosus (25.99%), Lactobacillus brevis (9.61%) and Pediococcus pentosaceus (19.77%). All the isolates were screened for their tolerance to olive leaf extract and oleuropein. Most of the isolates (85.3%) were found able to degrade oleuropein, when evaluated by either oleuropein or 5-Bromo- 4-chloro-3-indolyl ?-D-glucuronide (X-Gluc) as substrates. The biodegradation capacity of the selected strains of each species was confirmed by HPLC analysis.Un total de 177 cepas de bacterias ácido lácticas (LAB) fueron aisladas en las primeras etapas de la fermentación de aceitunas verdes marroquíes Picholine, incluyendo Lactobacillus plantarum (44.63%), Lactobacillus pentosus (25.99%), Lactobacillus brevis (9.61%) y Pediococcus pentosaceus (19.77%). Todos los aislados fueron evaluados mediante su tolerancia a extractos de hojas de olivo y oleuropeína. La mayoría de los aislados (85,3%) degradaron oleuropeína, cuando fueron evaluados usando oleuropeína o 5-Bromo-4-cloro- 3-indolil ?-D-glucuronido (X-Gluc) como sustrato. La capacidad de biodegradación de las cepas seleccionadas para cada especie fue confirmada mediante análisis por HPLC.

Ghabbour, N.; Lamzira, Z.; Thonart, P.; Cidalia, P.; Markaoui, M.; Asehraou, A.

2011-01-01

97

Biomarker evidence for green and purple sulphur bacteria in a stratified Palaeoproterozoic sea.  

UK PubMed Central (United Kingdom)

The disappearance of iron formations from the geological record approximately 1.8 billion years (Gyr) ago was the consequence of rising oxygen levels in the atmosphere starting 2.45-2.32 Gyr ago. It marks the end of a 2.5-Gyr period dominated by anoxic and iron-rich deep oceans. However, despite rising oxygen levels and a concomitant increase in marine sulphate concentration, related to enhanced sulphide oxidation during continental weathering, the chemistry of the oceans in the following mid-Proterozoic interval (approximately 1.8-0.8 Gyr ago) probably did not yet resemble our oxygen-rich modern oceans. Recent data indicate that marine oxygen and sulphate concentrations may have remained well below current levels during this period, with one model indicating that anoxic and sulphidic marine basins were widespread, and perhaps even globally distributed. Here we present hydrocarbon biomarkers (molecular fossils) from a 1.64-Gyr-old basin in northern Australia, revealing the ecological structure of mid-Proterozoic marine communities. The biomarkers signify a marine basin with anoxic, sulphidic, sulphate-poor and permanently stratified deep waters, hostile to eukaryotic algae. Phototrophic purple sulphur bacteria (Chromatiaceae) were detected in the geological record based on the new carotenoid biomarker okenane, and they seem to have co-existed with communities of green sulphur bacteria (Chlorobiaceae). Collectively, the biomarkers support mounting evidence for a long-lasting Proterozoic world in which oxygen levels remained well below modern levels.

Brocks JJ; Love GD; Summons RE; Knoll AH; Logan GA; Bowden SA

2005-10-01

98

Monitoring structural transformation of hydroxy-sulphate green rust in the presence of sulphate reducing bacteria  

International Nuclear Information System (INIS)

The activities of bacterial consortia enable organisms to maximize their metabolic capabilities. This article assesses the synergetic relationship between iron reducing bacteria (IRB), Shewanella putrefaciens and sulphate reducing bacteria (SRB) Desulfovibrio alaskensis. Thus, the aim of this study was first to form a biogenic hydroxy-sulpahte green rust GR2(SO4-2) through the bioreduction of lepidocrocite by S. putrefaciens and secondly to investigate if sulfate anions intercalated in the biogenic GR2(SO4-2) could serve as final electron acceptor for a sulfate reducing bacterium, D. alaskensis. The results indicate that the IRB lead to the formation of GR2(SO4-2) and this mineral serve as an electron acceptor for SRB. GR2(SO4-2) precipitation and its transformation was demonstrated by using X-ray diffraction (DRX), Moessbauer spectroscopy (TMS) and transmission electron spectroscopy (TEM). These observations point out the possible acceleration of steel corrosion in marine environment in presence of IRB/SRB consortia.

2006-01-01

99

Iron Sulfides and Sulfur Species Produced at (001) Hematite Surfaces in the Presence of Sulfate-Reducing Bacteria  

Energy Technology Data Exchange (ETDEWEB)

In the presence of sulfate-reducing bacteria (Desulfovibrio desulfuricans) hematite (a-Fe2O3) dissolution is affected and hydrogen sulfide, the product of sulfate reduction is released. As a consequence, ferrous ions are free to react with excess H2S to form insoluble iron sulfides. X-ray photoelectron spectra indicate binding energies consistent with the iron sulfides having a pyrrhotite structure (Fe2p3/2 708.4 eV; S2p3/2 161.5 eV). Other sulfur species identified at the surface include sulfate, sulfite and polysulfides. X-ray diffraction suggests an unidentifiable crystal structure at the hematite surface develops within 3 months, HRTEM confirms the presence of a hexagonal structure again suggesting the formation of pyrrhotite. The identification of pyrrhotite is inconsistent with previous reports in which mackinawite and greigite were products of biological sulfate reduction (Rickard 1969; Herbert et al 1998). The apparent differences in stoiciometries may be related to the availability of Fe2+(aq.) at the mineral surface through respiratory iron reduction by subsurface bacteria. The significance of pyrrhotite and polysulfide production in relation to the S- and Fe-cycles and to trace metal bioavailability is discussed.

Neal, Andrew L.; Techkarnjanaruk, Somkiet; Dohnalkova, Alice; McCready, David E.; Peyton, Brent M.; Geesey, Gill G.

2001-01-01

100

Use of green fluorescent protein to tag and investigate gene expression in marine bacteria.  

UK PubMed Central (United Kingdom)

Two broad-host-range vectors previously constructed for use in soil bacteria (A. G. Matthysse, S. Stretton, C. Dandie, N. C. McClure, and A. E. Goodman, FEMS Microbiol. Lett. 145:87-94, 1996) were assessed by epifluorescence microscopy for use in tagging three marine bacterial species. Expression of gfp could be visualized in Vibrio sp. strain S141 cells at uniform levels of intensity from either the lac or the npt-2 promoter, whereas expression of gfp could be visualized in Psychrobacter sp. strain SW5H cells at various levels of intensity only from the npt-2 promoter. Green fluorescent protein (GFP) fluorescence was not detected in the third species, Pseudoalteromonas sp. strain S91, when the gfp gene was expressed from either promoter. A new mini-Tn10-kan-gfp transposon was constructed to investigate further the possibilities of fluorescence tagging of marine bacteria. Insertion of mini-Tn10-kan-gfp generated random stable mutants at high frequencies with all three marine species. With this transposon, strongly and weakly expressed S91 promoters were isolated. Visualization of GFP by epifluorescence microscopy was markedly reduced when S91 (mini-Tn10-kan-gfp) cells were grown in rich medium compared to that when cells were grown in minimal medium. Mini-Tn10-kan-gfp was used to create an S91 chitinase-negative, GFP-positive mutant. Expression of the chi-gfp fusion was induced in cells exposed to N'-acetylglucosamine or attached to chitin particles. By laser scanning confocal microscopy, biofilms consisting of microcolonies of chi-negative, GFP+ S91 cells were found to be localized several microns from a natural chitin substratum. Tagging bacterial strains with GFP enables visualization of, as well as monitoring of gene expression in, living single cells in situ and in real time.

Stretton S; Techkarnjanaruk S; McLennan AM; Goodman AE

1998-07-01

 
 
 
 
101

Green tea catechins quench the fluorescence of bacteria-conjugated alexa fluor dyes.  

Science.gov (United States)

Accumulating evidence suggests that Green tea polyphenolic catechins, especially the (-)-epigallocatechin gallate (EGCG), can be cross-linked to many proteins, and confer a wide range of anti-bacterial activities possibly by damaging microbial cytoplasmic lipids and proteins. At the doses that conferred protection against lethal polymicrobial infection (induced by cecal ligation and puncture), EGCG significantly reduced bacterial loads particularly in the liver and lung. To elucidate its bactericidal mechanisms, we determined whether EGCG affected the fluorescence intensities of bacteria-conjugated Alexa Fluor 488 or 594 dyes. When mixed with unconjugated Alexa Fluor 488 or 594 dyes, EGCG or analogs did not affect the fluorescence intensity of these dyes. In a sharp contrast, EGCG and some analogs (e.g., Catechin Gallate, CG), markedly reduced the fluorescence intensity of Gram-positive Staphylococcus aureus-conjugated Alexa 594 and Gram-negative Escherichia coli-conjugated Alexa 488. Interestingly, co-treatment with ethanol impaired the EGCG-mediated fluorescence quenching of the G(+) S. aureus, but not of the G(-) E. coli-conjugated Alexa Flour dyes. In light of the notion that Alexa Fluor dyes can be quenched by aromatic amino acids, it is plausible that EGCG exerts antimicrobial activities possibly by altering microbial protein conformations and functions. This possibility can now be explored by screening other fluorescence-quenching agents for possible antimicrobial activities. PMID:24011199

Zhao, Lin; Li, Wei; Zhu, Shu; Tsai, Sheena; Li, Jianhua; Tracey, Kevin J; Wang, Ping; Fan, Saijun; Sama, Andrew E; Wang, Haichao

2013-10-01

102

Green tea catechins quench the fluorescence of bacteria-conjugated Alexa fluor dyes.  

UK PubMed Central (United Kingdom)

Accumulating evidence suggests that Green tea polyphenolic catechins, especially the (-)-epigallocatechin gallate (EGCG), can be cross-linked to many proteins, and confer a wide range of anti-bacterial activities possibly by damaging microbial cytoplasmic lipids and proteins. At the doses that conferred protection against lethal polymicrobial infection (induced by cecal ligation and puncture), EGCG significantly reduced bacterial loads particularly in the liver and lung. To elucidate its bactericidal mechanisms, we determined whether EGCG affected the fluorescence intensities of bacteria-conjugated Alexa Fluor 488 or 594 dyes. When mixed with unconjugated Alexa Fluor 488 or 594 dyes, EGCG or analogs did not affect the fluorescence intensity of these dyes. In a sharp contrast, EGCG and some analogs (e.g., Catechin Gallate, CG), markedly reduced the fluorescence intensity of Gram-positive Staphylococcus aureus-conjugated Alexa 594 and Gram-negative Escherichia coli-conjugated Alexa 488. Interestingly, co-treatment with ethanol impaired the EGCG-mediated fluorescence quenching of the G(+) S. aureus, but not of the G(-) E. coli-conjugated Alexa Flour dyes. In light of the notion that Alexa Fluor dyes can be quenched by aromatic amino acids, it is plausible that EGCG exerts antimicrobial activities possibly by altering microbial protein conformations and functions. This possibility can now be explored by screening other fluorescence-quenching agents for possible antimicrobial activities.

Zhao L; Li W; Zhu S; Tsai S; Li J; Tracey KJ; Wang P; Fan S; Sama AE; Wang H

2013-10-01

103

Structure, Function and Reconstitution of Antenna Complexes from Green Photosynthetic Bacteria  

Energy Technology Data Exchange (ETDEWEB)

This project is concerned with the structure and function of the chlorosome antennas found in green photosynthetic bacteria. Chlorosomes are ellipsoidal structures attached to the cytoplasmic side of the inner cell membrane. These antenna complexes provide a very large absorption cross section for light capture. Evidence is overwhelming that the chlorosome represents a very different type of antenna from that found in any other photosynthetic system yet studied. It is now clear that chlorosomes do not contain traditional pigment-proteins, in which the pigments bind to specific sites on proteins. Instead, the chlorosome pigments are organized in vivo into pigment oligomers in which direct pigment-pigment interactions are of dominant importance. Our group has used a multidisciplinary approach to investigate this unique system, as well as the complexes that they directly interact with. Our work has included using model systems, numerous types of both steady-state and ultrafast spectroscopy, molecular biology, protein chemistry and X-ray crystallography. Details of our recent results using these approaches are given below and in the references. Numbers cited in the sections refer to DOE-sponsored publications that are listed below. Only publications dated 2001-2004 or later are included in this report. In addition to the primary literature reports, a comprehensive review of this area of research has been written as well as a commentary.

Robert E. Blankenship

2005-08-10

104

Characteristics of purple non-sulfur bacteria grown under Stevia residue extractions.  

UK PubMed Central (United Kingdom)

As a consequence of the large-scale cultivation of Stevia plants, releases of plant residues, the byproduct after sweetener extraction, to the environment are inevitable. Stevia residue and its effluent after batching up contain large amounts of organic matters with small molecular weight, which therefore are a potential pollution source. Meanwhile they are favorite substrates for microorganism growths. This investigation was aimed to utilize the simulated effluent of Stevia residue to enrich the representative purple non-sulfur bacterium (PNSB), Rhodopseudomonas palustris (Rps. palustris), which has important economic values. The growth profile and quality of Rps. palustris were characterized by spectrophotometry, compared to those grown in common PNSB mineral synthetic medium. Our results revealed that the simulated effluent of Stevia residue not only stimulated Rps. palustris growth to a greater extent, but also increased its physiologically active cytochrome concentrations and excreted indole-3-acetic acid (IAA) content. This variation in phenotype of Rps. palustris could result from the shift in its genotype, further revealed by the repetitive sequence-based PCR (rep-PCR) fingerprinting analysis. Our results showed that the effluent of Stevia residue was a promising substrate for microbial growth. This article is protected by copyright. All rights reserved.

Xu J; Feng Y; Wang Y; Lin X

2013-07-01

105

Screening of antagonistic bacteria against the green mold disease (Trichoderma harzianum Rifai) of Grey Oyster Mushroom (Pleurotus pulmonarius (Fr.) Quel.)  

Directory of Open Access Journals (Sweden)

Full Text Available A total of 174 strains of bacteria antagonistic against the green mold (Trichoderma harzianum), isolated from cultivating bags and fruiting bodies of the mushrooms, were screened for effects on mushroom mycelia and ability to control the green mold disease. Twenty-eight of them promoted the primodia formation of the Pleurotus pulmonarius mycelia on agar plates. Twenty-two isolates were selected and further tested in a mushroom house. Cell suspension of each isolate was prepared and sprayed onto the spawn surface of P. pulmonarius. Fifteen isolates shortened the times required from watering to 2nd and 3rd flushing and increased yield of the basidiocarps by 1.1-34.3% over 30 days. Six isolates of bacteria which showed an inhibitory effect against T. harzianum, enhanced primordia formation and increased yield of P. pulmonarius were selected and used for control testing in a cultivation house. The suspension of each isolate was sprayed onto the spawn surface immediately after exposure to the air in the mushroom house, followed by spore suspension of T. harzianum two days later. The number of infected bags was counted at 30 days after inoculation and the cumulative yield was compared after 60 days. The results showed that bacteria isolate B012-022 was highly effective in suppressing the green mold disease.Only 6.7% of the cultivating bags were found to be infected by T. harzianum when bacteria isolate B012-022 was applied. Cumulative yield obtained from 900 g of 94% sawdust + 5% rice bran + 1% Ca(OH)2 was 300.0 g/bag after 60 days, 71.1% higher than the bags infected by the green mold and without bacterial spraying. Identification of the six bacterial isolates showed all to be Bacillus spp.

Maneechai, P.; Petcharat, V.; Chuenchit, S.; Nualsri, C.

2005-01-01

106

A monogalactosyldiacylglycerol synthase found in the green sulfur bacterium Chlorobaculum tepidum reveals important roles for galactolipids in photosynthesis.  

Science.gov (United States)

Monogalactosyldiacylglycerol (MGDG), which is conserved in almost all photosynthetic organisms, is the most abundant natural polar lipid on Earth. In plants, MGDG is highly accumulated in the chloroplast membranes and is an important bulk constituent of thylakoid membranes. However, precise functions of MGDG in photosynthesis have not been well understood. Here, we report a novel MGDG synthase from the green sulfur bacterium Chlorobaculum tepidum. This enzyme, MgdA, catalyzes MGDG synthesis using UDP-Gal as a substrate. The gene encoding MgdA was essential for this bacterium; only heterozygous mgdA mutants could be isolated. An mgdA knockdown mutation affected in vivo assembly of bacteriochlorophyll c aggregates, suggesting the involvement of MGDG in the construction of the light-harvesting complex called chlorosome. These results indicate that MGDG biosynthesis has been independently established in each photosynthetic organism to perform photosynthesis under different environmental conditions. We complemented an Arabidopsis thaliana MGDG synthase mutant by heterologous expression of MgdA. The complemented plants showed almost normal levels of MGDG, although they also had abnormal morphological phenotypes, including reduced chlorophyll content, no apical dominance in shoot growth, atypical flower development, and infertility. These observations provide new insights regarding the importance of regulated MGDG synthesis in the physiology of higher plants. PMID:21764989

Masuda, Shinji; Harada, Jiro; Yokono, Makio; Yuzawa, Yuichi; Shimojima, Mie; Murofushi, Kazuhiro; Tanaka, Hironori; Masuda, Hanako; Murakawa, Masato; Haraguchi, Tsuyoshi; Kondo, Maki; Nishimura, Mikio; Yuasa, Hideya; Noguchi, Masato; Oh-Oka, Hirozo; Tanaka, Ayumi; Tamiaki, Hitoshi; Ohta, Hiroyuki

2011-07-15

107

A monogalactosyldiacylglycerol synthase found in the green sulfur bacterium Chlorobaculum tepidum reveals important roles for galactolipids in photosynthesis.  

UK PubMed Central (United Kingdom)

Monogalactosyldiacylglycerol (MGDG), which is conserved in almost all photosynthetic organisms, is the most abundant natural polar lipid on Earth. In plants, MGDG is highly accumulated in the chloroplast membranes and is an important bulk constituent of thylakoid membranes. However, precise functions of MGDG in photosynthesis have not been well understood. Here, we report a novel MGDG synthase from the green sulfur bacterium Chlorobaculum tepidum. This enzyme, MgdA, catalyzes MGDG synthesis using UDP-Gal as a substrate. The gene encoding MgdA was essential for this bacterium; only heterozygous mgdA mutants could be isolated. An mgdA knockdown mutation affected in vivo assembly of bacteriochlorophyll c aggregates, suggesting the involvement of MGDG in the construction of the light-harvesting complex called chlorosome. These results indicate that MGDG biosynthesis has been independently established in each photosynthetic organism to perform photosynthesis under different environmental conditions. We complemented an Arabidopsis thaliana MGDG synthase mutant by heterologous expression of MgdA. The complemented plants showed almost normal levels of MGDG, although they also had abnormal morphological phenotypes, including reduced chlorophyll content, no apical dominance in shoot growth, atypical flower development, and infertility. These observations provide new insights regarding the importance of regulated MGDG synthesis in the physiology of higher plants.

Masuda S; Harada J; Yokono M; Yuzawa Y; Shimojima M; Murofushi K; Tanaka H; Masuda H; Murakawa M; Haraguchi T; Kondo M; Nishimura M; Yuasa H; Noguchi M; Oh-Oka H; Tanaka A; Tamiaki H; Ohta H

2011-07-01

108

Diel Variations in Carbon Metabolism by Green Nonsulfur-Like Bacteria in Alkaline Siliceous Hot Spring Microbial Mats from Yellowstone National Park  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Green nonsulfur-like bacteria (GNSLB) in hot spring microbial mats are thought to be mainly photoheterotrophic, using cyanobacterial metabolites as carbon sources. However, the stable carbon isotopic composition of typical Chloroflexus and Roseiflexus lipids suggests photoautotrophic metabolism of G...

van der Meer, Marcel T. J.; Schouten, Stefan; Bateson, Mary M.; Nübel, Ulrich; Wieland, Andrea; Kühl, Michael; de Leeuw, Jan W.

109

Comparison of the physical characteristics of chlorosomes from three different phyla of green phototrophic bacteria.  

Science.gov (United States)

Chlorosomes, the major antenna complexes in green sulphur bacteria, filamentous anoxygenic phototrophs, and phototrophic acidobacteria, are attached to the cytoplasmic side of the inner cell membrane and contain thousands of bacteriochlorophyll (BChl) molecules that harvest light and channel the energy to membrane-bound reaction centres. Chlorosomes from phototrophs representing three different phyla, Chloroflexus (Cfx.) aurantiacus, Chlorobaculum (Cba.) tepidum and the newly discovered "Candidatus (Ca.) Chloracidobacterium (Cab.) thermophilum" were analysed using PeakForce Tapping atomic force microscopy (PFT-AFM). Gentle PFT-AFM imaging in buffered solutions that maintained the chlorosomes in a near-native state revealed ellipsoids of variable size, with surface bumps and undulations that differ between individual chlorosomes. Cba. tepidum chlorosomes were the largest (133×57×36nm; 141,000nm(3) volume), compared with chlorosomes from Cfx. aurantiacus (120×44×30nm; 84,000nm(3)) and Ca. Cab. thermophilum (99×40×31nm; 65,000nm(3)). Reflecting the contributions of thousands of pigment-pigment stacking interactions to the stability of these supramolecular assemblies, analysis by nanomechanical mapping shows that chlorosomes are highly stable and that their integrity is disrupted only by very strong forces of 1000-2000pN. AFM topographs of Ca. Cab. thermophilum chlorosomes that had retained their attachment to the cytoplasmic membrane showed that this membrane dynamically changes shape and is composed of protrusions of up to 30nm wide and 6nm above the mica support, possibly representing different protein domains. Spectral imaging revealed significant heterogeneity in the fluorescence emission of individual chlorosomes, likely reflecting the variations in BChl c homolog composition and internal arrangements of the stacked BChls within each chlorosome. PMID:23867748

Adams, Peter G; Cadby, Ashley J; Robinson, Benjamin; Tsukatani, Yusuke; Tank, Marcus; Wen, Jianzhong; Blankenship, Robert E; Bryant, Donald A; Hunter, C Neil

2013-07-16

110

Comparison of the physical characteristics of chlorosomes from three different phyla of green phototrophic bacteria.  

UK PubMed Central (United Kingdom)

Chlorosomes, the major antenna complexes in green sulphur bacteria, filamentous anoxygenic phototrophs, and phototrophic acidobacteria, are attached to the cytoplasmic side of the inner cell membrane and contain thousands of bacteriochlorophyll (BChl) molecules that harvest light and channel the energy to membrane-bound reaction centres. Chlorosomes from phototrophs representing three different phyla, Chloroflexus (Cfx.) aurantiacus, Chlorobaculum (Cba.) tepidum and the newly discovered "Candidatus (Ca.) Chloracidobacterium (Cab.) thermophilum" were analysed using PeakForce Tapping atomic force microscopy (PFT-AFM). Gentle PFT-AFM imaging in buffered solutions that maintained the chlorosomes in a near-native state revealed ellipsoids of variable size, with surface bumps and undulations that differ between individual chlorosomes. Cba. tepidum chlorosomes were the largest (133×57×36nm; 141,000nm(3) volume), compared with chlorosomes from Cfx. aurantiacus (120×44×30nm; 84,000nm(3)) and Ca. Cab. thermophilum (99×40×31nm; 65,000nm(3)). Reflecting the contributions of thousands of pigment-pigment stacking interactions to the stability of these supramolecular assemblies, analysis by nanomechanical mapping shows that chlorosomes are highly stable and that their integrity is disrupted only by very strong forces of 1000-2000pN. AFM topographs of Ca. Cab. thermophilum chlorosomes that had retained their attachment to the cytoplasmic membrane showed that this membrane dynamically changes shape and is composed of protrusions of up to 30nm wide and 6nm above the mica support, possibly representing different protein domains. Spectral imaging revealed significant heterogeneity in the fluorescence emission of individual chlorosomes, likely reflecting the variations in BChl c homolog composition and internal arrangements of the stacked BChls within each chlorosome.

Adams PG; Cadby AJ; Robinson B; Tsukatani Y; Tank M; Wen J; Blankenship RE; Bryant DA; Hunter CN

2013-10-01

111

Characterization of purple sulfur bacteria from the South Andros Black Hole cave system: highlights taxonomic problems for ecological studies among the genera Allochromatium and Thiocapsa.  

Science.gov (United States)

A dense 1 m thick layer of phototrophic purple sulfur bacteria is present at the pycnocline (17.8 m depth) in the meromictic South Andros Black Hole cave system (Bahamas). Two purple sulfur bacteria present in samples collected from this layer have been identified as belonging to the family Chromatiaceae. One isolate (BH-1), pink coloured, is non-motile, non-gas vacuolated, 2-3 microm in diameter and surrounded by a capsule. The other isolates (BH-2 and BH-2.4), reddish-brown coloured, are small celled (4 microm x 2 microm), motile by means of a single polar flagellum. In both isolates (BH-1 and BH-2), the intracellular photosynthetic membranes are of the vesicular type and bacteriochlorophyll a and carotenoids of the normal spirilloxanthin series are present. Both isolates grow well in the presence of sulfide and carbon dioxide in the light. During photoautotrophic growth sulfur globules are stored intracellularly as intermediate oxidation products. According to the 16S rRNA gene sequence data the isolates belong to the genera Thiocapsa and Allochromatium. However, at the species level a number of inconsistencies exist between the phenotypic and phylogenetic data, highlighting taxonomic problems within these genera. These inconsistencies may have implications for microbiologists studying the ecology of anoxygenic phototrophs. For ecologists studying the functioning of an ecosystem it may not be particularly important to know whether a specific isolate belongs to one species or another. However, if one wants to study the role of different populations within a particular functional group then the species concept is important. This study demonstrates that further work is still required on the taxonomy of purple sulfur bacteria in order that microbial ecologists are able to accurately identify a population/species isolated from hitherto undescribed aquatic ecosystems. PMID:16011763

Herbert, Rodney A; Ranchou-Peyruse, Anthony; Duran, Robert; Guyoneaud, Rémy; Schwabe, Stephanie

2005-08-01

112

green ??????  

Directory of Open Access Journals (Sweden)

Full Text Available The “green” topic follows the “youngsters”, which is quite natural for the Russian language.Traditionally these words put together sound slightly derogatory. However, “green” also means fresh, new and healthy.For Russia, and for Siberia in particular, “green” architecture does sound new and fresh. Forced by the anxious reality, we are addressing this topic intentionally. The ecological crisis, growing energy prices, water, air and food deficits… Alexander Rappaport, our regular author, writes: “ It has been tolerable until a certain time, but under transition to the global civilization, as the nature is destroyed, and swellings of megapolises expand incredibly fast, the size and the significance of all these problems may grow a hundredfold”.However, for this very severe Siberian reality the newness of “green” architecture may turn out to be well-forgotten old. A traditional Siberian house used to be built on principles of saving and environmental friendliness– one could not survive in Siberia otherwise.Probably, in our turbulent times, it is high time to fasten “green belts”. But we should keep from enthusiastic sticking of popular green labels or repainting of signboards into green color. We should avoid being drowned in paper formalities under “green” slogans. And we should prevent the Earth from turning into the planet “Kin-dza-dza”.????? ?? ????? «??????» ???????????? ??? ???????? ????? ??????? ??????? ???? «??????».????????? «?????? – ??????» ??????????? ????? ????????? ????????????????? ????????. ?????? «???????» ?????? ??? ? ??????, ?????, ????????.??? ??????, ? ???????? ??? ?????? ???? «???????» ??????????? ????????????? ?????? ????? ? ??????. ?? ?? ???????? ???????? ? ???? ????: ??? ????????? ????????? ????????????????. ????????????? ??????, ???????? ???? ?? ??????????????, ??????? ????, ???????, ???… ??? ?????????? ????? ????????? ????????? ?????: «?? ???? ?? ??????? ??? ??? ???? ???????, ?? ? ????????? ? ?????????? ???????????, ?? ???? ?????????? ???????? ?????????? ??????? ? ??????????? ???????? ???????????, ??? ??? ???????? ????? ????????? ??????? ? ???????? ? ??????????».???????, ?????? ??? ??????? ????????? ???????????????? ??????? «???????» ??????????? ????? ????????? ?????? ??????? ??????. ???????????? ????????? ??? ?????? ???????? ?? ????????? ???????? ? ????????????? – ????? ? ?????? ???? ? ?? ??????.????????, ?????? ??????, ? ???? ???????????? ?????, ?????? ???? ?????????? «??????? ?????» (?????????? green belt – ???? ????????????). ???? ?? ?? ???????? ???????????? ?????? ??????? ????????, ??????????????? ??????? ? ??????? ????. ?? ??????? ? ???????? ????????????? ??? «????????» ?????????. ? ?? ???? ????? ??????? ???????????? ? ??????? ???-???-???.

Elena Grigoryeva

2011-01-01

113

Augmentation of potential phosphate solubilizing bacteria (PSB) stimulate growth of green mustard (Brasica caventis Oed.) in marginal soil  

Directory of Open Access Journals (Sweden)

Full Text Available The potential of phosphate solubilizing bacteria/PSB (Bacillus megaterium, B. pantothenticus, Chromobacterium lividum and Klebsiella aerogenes) were used as biofertilizer to increase the fresh leaf production of green mustard (Brasica caventis Oed.). An experiment was conducted at green house condition. The experiment were used 18 treatments such as single isolate of potential PSB (A,B,C,D), inoculants contain two isolates of potential PSB (E,F,G,H,I,J), inoculants contain three isolates of potential PSB (K, L, M, N), inoculants contain four isolate of potential PSB (O), chemistry fertilizer (P = control 1), organic fertilizer (Q = control 2), and without fertilizer (R = control 3). The treatments were arranged in Completely Randomized Design (CRD) with 5 replications. The result showed that the inoculants of potential PSB increased the fresh plant production of green mustard. The mix of four isolates of potential PSB (inoculants O) was the best to increase the fresh plant production of green mustard until 32.87% than other PSB inoculants, 207.84% than control 1,217.23% than control 2, and 930.60% than control 3.

SRI WIDAWATI; SULIASIH

2006-01-01

114

Microbial conversion of sulfur dioxide in flue gas to sulfide using bulk drug industry wastewater as an organic source by mixed cultures of sulfate reducing bacteria  

International Nuclear Information System (INIS)

Mixed cultures of sulfate reducing bacteria (SRB) were isolated from anaerobic cultures and enriched with SRB media. Studies on batch and continuous reactors for the removal of SO2 with bulk drug industry wastewater as an organic source using isolated mixed cultures of SRB revealed that isolation and enrichment methodology adopted in the present study were apt to suppress the undesirable growth of anaerobic bacteria other than SRB. Studies on anaerobic reactors showed that process was sustainable at COD/S ratio of 2.2 and above with optimum sulfur loading rate (SLR) of 5.46 kg S/(m3 day), organic loading rate (OLR) of 12.63 kg COD/(m3 day) and at hydraulic residence time (HRT) of 8 h. Free sulfide (FS) concentration in the range of 300-390 mg FS/l was found to be inhibitory to mixed cultures of SRB used in the present studies.

2007-08-25

115

Enrichment and identification of large filamentous sulfur bacteria related to Beggiatoa species from brackishwater ecosystems of Tamil Nadu along the southeast coast of India.  

UK PubMed Central (United Kingdom)

Beggiatoa species are filamentous sulfide-oxidizing bacteria belonging to the family Beggiatoaceae that contains several largest bacteria known today. These large sulfur bacteria occur in diverse ecosystems and play an important role in the global sulfur, nitrogen and phosphorus cycle. In this study, sediment samples from brackishwater shrimp culture ponds and other brackishwater ecosystems from Tamil Nadu, southeast coast of India, were enriched for Beggiatoa species. Extracted hay medium supplemented with catalase was used and were incubated for two weeks at 28°C. Out of seven set-ups, four yielded positive growth of filamentous sulfide-oxidizing bacteria. The filaments were several millimeters long, ranged in width between 2 and 15 ?m and exhibited typical gliding motility. The 16S rRNA gene of four single filaments representing the four positive enrichments was subjected to PCR-DGGE followed by sequencing. All four filaments were affiliated to the Beggiatoaceae, but showed less than 89% identity with the Beggiatoa type strain Beggiatoa alba and less than 93% identity with any other sequence of the family. One of the four filaments revealed a nearly full-length 16S rDNA sequence (1411bp) and it formed a monophyletic cluster with two of the partial DGGE-16S rRNA gene sequences (99-100% identity) within the Beggiatoa species cluster. These organisms could possibly represent a novel genus within the family Beggiatoaceae. The fourth partial sequence affiliated with less than 93% sequence identity to the genera Parabeggiatoa, Thioploca and Thiopilula, and was likewise strongly delineated from any sequence published in the family.

Saravanakumar C; Dineshkumar N; Alavandi SV; Salman V; Poornima M; Kalaimani N

2012-09-01

116

Azoreductase activity in bacteria associated with the greening of instant chocolate puddings.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Pseudomonas sp. strain AZR1 and Klebsiella sp. strain AZR2 were isolated from reconstituted instant chocolate puddings that had turned green and were found to have azoreductase activity. This activity was inducible and NADH dependent. Differences in dye reduction rates between the two strains were a...

Dykes, G A; Timm, R G; von Holy, A

117

New unstable variants of green fluorescent protein for studies of transient gene expression in bacteria  

DEFF Research Database (Denmark)

Use of the green fluorescent protein (Gfp) from the jellyfish Aequorea victoria ia is a powerful method for nondestructive in situ monitoring, since expression of green fluorescence does not require any substrate addition. To expand the use of Gfp as a reporter protein, new variants have been constructed by the addition of short peptide sequences to the C-terminal end of intact Gfp. This rendered the Gfp susceptible to the action of indigenous housekeeping proteases, resulting in protein variants with half-lives ranging from 40 min to a few hours when synthesized in Escherichia coli and Pseudomonas putida. The new Gfp variants should be useful for in situ studies of temporal gene expression.

Andersen, Jens Bo; Sternberg, Claus

1998-01-01

118

Potential for plant growth promotion in groundnut (Arachis hypogaea L.) cv. ALR-2 by co-inoculation of sulfur-oxidizing bacteria and Rhizobium.  

Science.gov (United States)

The use of Rhizobium inoculant for groundnut is a common practice in India. Also, co-inoculation of Rhizobium with other plant growth-promoting bacteria received considerable attention in legume growth promotion. Hence, in the present study we investigated effects of co-inoculating the sulfur (S)-oxidizing bacterial strains with Rhizobium, a strain that had no S-oxidizing potential in groundnut. Chemolithotrophic S-oxidizing bacterial isolates from different sources by enrichment isolation technique included three autotrophic (LCH, SWA5 and SWA4) and one heterotrophic (SGA6) strains. All the four isolates decreased the pH of the growth medium through oxidation of elemental S to sulfuric acid. Characterization revealed that these isolates tentatively placed into the genus Thiobacillus. Clay-based pellet formulation (2.5 x 10(7) cf ug(-1) pellet) of the Thiobacillus strains were developed and their efficiency to promote plant growth was tested in groundnut under pot culture and field conditions with S-deficit soil. Experiments in pot culture yielded promising results on groundnut increasing the plant biomass, nodule number and dry weight, and pod yield. Co-inoculation of Thiobacillus sp. strain LCH (applied at 60 kg ha(-1)) with Rhizobium under field condition recorded significantly higher nodule number, nodule dry weight and plant biomass 136.9 plant(-1), 740.0mg plant(-1) and 15.0 g plant(-1), respectively, on 80 days after sowing and enhanced the pod yield by 18%. Also inoculation of S-oxidizing bacteria increased the soil available S from 7.4 to 8.43 kg ha(-1). These results suggest that inoculation of S-oxidizing bacteria along with rhizobia results in synergistic interactions promoting the yield and oil content of groundnut, in S-deficit soils. PMID:16574388

Anandham, R; Sridar, R; Nalayini, P; Poonguzhali, S; Madhaiyan, M; Sa, Tongmin

2006-03-30

119

Green Fluorescent Protein-Labeled Monitoring Tool To Quantify Conjugative Plasmid Transfer between Gram-Positive and Gram-Negative Bacteria  

Digital Repository Infrastructure Vision for European Research (DRIVER)

On the basis of pIP501, a green fluorescent protein (GFP)-tagged monitoring tool was constructed for quantifying plasmid mobilization among Gram-positive bacteria and between Gram-positive Enterococcus faecalis and Gram-negative Escherichia coli. Furthermore, retromobilization of the GFP-tagged moni...

Arends, Karsten; Schiwon, Katarzyna; Sakinc, Türkan; Hübner, Johannes; Grohmann, Elisabeth

120

Analysis of community composition of sulfur-oxidizing bacteria in hypersaline and soda lakes using soxB as a functional molecular marker.  

UK PubMed Central (United Kingdom)

The diversity of soxB gene encoding a key enzyme of the Sox pathway sulfate thiohydrolase has been investigated in pure cultures of various halophilic and haloalkaliphilic sulfur-oxidizing bacteria (SOB) and in salt and soda lakes in southwestern Siberia and Egypt. The gene was detected in the majority of strains belonging to eleven SOB genera excluding members of genera Thiohalospira and Thioalkalimicrobium. The uncultured diversity of soxB in salt and soda lakes was low with a majority of detected sequences belonging to autotrophic SOB from the Gammaproteobacteria. In addition, the soxB analysis allowed detection of putative heterotrophic Gamma- and Alphaproteobacterial SOB yet unknown in culture. All clone libraries obtained from soda lakes contained soxB belonging to the genus Thioalkalivibrio in agreement with the cultivation results. Besides, representatives of the genera Halothiobacillus, Marinobacter, and Halochromatium and of the family Rhodobacteraceae have been detected in both type of saline lakes.

Tourova TP; Slobodova NV; Bumazhkin BK; Kolganova TV; Muyzer G; Sorokin DY

2013-05-01

 
 
 
 
121

Seawater-based methane production from blue-green algae biomass by marine bacteria coculture  

Energy Technology Data Exchange (ETDEWEB)

Marine-enriched culture NKM 004 produced methane from various carbohydrates, but methane production was inhibited by sulfate and acetate accumulated in the medium. On the other hand, marine methanogenic bacterium NKM 006 produced methane from acetate and methyltrophic substrates, and methane production was not inhibited by sulfate. The mixture of NKM 004 and NKM 006 continuously produced methane from marine blue-green algae Dermocarpa species NKBG 102B at 54 ..mu..mol/L medium/h for 200 h and the dry weight of the algal biomass was decreased to 25% of the initial weight in the natural seawater. Conversion of algal carbohydrate (glucose equivalent) to methane was 65%. Results indicate that this system is promising for methane production based on seawater and solar energy.

Matsunaga, T.; Izumida, H.

1984-01-01

122

Chlorobium ferrooxidans sp. nov., a phototrophic green sulfur bacterium that oxidizes ferrous iron in coculture with a "Geospirillum" sp. strain  

Digital Repository Infrastructure Vision for European Research (DRIVER)

A green phototrophic bacterium was enriched with ferrous iron as sole electron donor and was isolated in defined coculture with a spirilloid chemoheterotrophic bacterium. The coculture oxidized ferrous iron to ferric iron with stoichiometric formation of cell mass from carbon dioxide. Sulfide, thios...

Heising, Silke; Richter, Lothar; Ludwig, Wolfgang; Schink, Bernhard

123

Bioenergetic studies of coal sulfur oxidation by extremely thermophilic bacteria. Final report, September 15, 1992--August 31, 1997  

Energy Technology Data Exchange (ETDEWEB)

Thermoacidophilic microorganisms have been considered for inorganic sulfur removal from coal because of expected improvements in rates of both biotic and abiotic sulfur oxidation reactions with increasing temperature. In this study, the bioenergetic response of the extremely thermoacidophilic archaeon, Metallosphaera sedula, to environmental changes have been examined in relation to its capacity to catalyze pyrite oxidation in coal. Given an appropriate bioenergetic challenge, the metabolic response was to utilize additional amounts of energy sources (i.e., pyrite) to survive. Of particular interest were the consequences of exposing the organism to various forms of stress (chemical, nutritional, thermal, pH) in the presence of coal pyrite. Several approaches to take advantage of stress response to accelerate pyrite oxidation by this organism were examined, including attempts to promote acquired thermal tolerance to extend its functional range, exposure to chemical uncouplers and decouplers, and manipulation of heterotrophic and chemolithotrophic tendencies to optimize biomass concentration and biocatalytic activity. Promising strategies were investigated in a continuous culture system. This study identified environmental conditions that promote better coupling of biotic and abiotic oxidation reactions to improve biosulfurization rates of thermoacidophilic microorganisms.

Kelly, R.M.; Han, C.J.

1997-12-31

124

Sulfur Mustard  

Science.gov (United States)

... What's New A - Z Index Facts About Sulfur Mustard What sulfur mustard is Sulfur mustard is a type of chemical ... is in liquid or solid form. Where sulfur mustard is found and how it is used Sulfur ...

125

Green fluorescent protein-labeled monitoring tool to quantify conjugative plasmid transfer between Gram-positive and Gram-negative bacteria.  

UK PubMed Central (United Kingdom)

On the basis of pIP501, a green fluorescent protein (GFP)-tagged monitoring tool was constructed for quantifying plasmid mobilization among Gram-positive bacteria and between Gram-positive Enterococcus faecalis and Gram-negative Escherichia coli. Furthermore, retromobilization of the GFP-tagged monitoring tool was shown from E. faecalis OG1X into the clinical isolate E. faecalis T9.

Arends K; Schiwon K; Sakinc T; Hübner J; Grohmann E

2012-02-01

126

Macro-benefits from boron, zinc and sulfur application in Indian SAT a step for grey to green revolution in agriculture  

Directory of Open Access Journals (Sweden)

Full Text Available The semi-arid tropics (SAT), spread over 11.6 million KM square worldwide, is home to millions of poor people. The soils are low in fertility and degraded to varying extent. The climate is characterized by undependable rainfall, high average temperature and water stress situations for crop growth. The SAT is densely populated and a large number of poor in this region depend on agriculture. The green revolution in Asia bypassed the large tracts of rainfed systems. ICRISAT is committed to improve livelihoods of millions of poor living in the SAT by undertaking agricultural research for impact in a partnership mode. The new watershed model emphasize the management of water as an entry point for improving livelihoods through convergence of natural resource-based activities. ICRISAT's on-farm community watershed research in Asia revealed that the SAT's subsistence agricultural systems have soils depleted not only in macronutrients but also in micronutrients such as zinc and boron, and secondary nutrients like sulfur beyond the critical limits. Widespread (80-100%) deficiencies of micro and secondary nutrients were observed in farmers' field in Andhra Pradesh, India. Substantial increase in yields by 20 to 80% due to micronutrient amendments, and a further increase by 70 to 120% due to micronutrients and adequate nitrogen (N) and phosphorus (P) amendments in a number of crops (maize, sorghum, mung bean, pigeonpea, castor, chickpea) in farmers' fields were observed. Besides minimizing land degradation, increased use efficiency of the inputs such as N and P fertilizers, as well as rainwater, resulted in increased profits and increased productivity. These natural resource management (NRM) interventions are integrated with improved genotypes to harness the full benefits in the watershed. The integrated genetic and natural resource management (IGNRM) approach adopted in watersheds will thus make the grey to green revolution a reality.

TJ Rego; SP Wani; KL Sahrawat; G Pardhasaradhi

2006-01-01

127

Green Algae  

Science.gov (United States)

Color photomicrographs of several species of green algae with brief descriptions of their chief characteristics and habitat. Scroll to the bottom of the page to links to bacteria, and more protists including diatoms, desmids and rotifers.

Van Egmond, Wim

2010-01-01

128

Developing a biofilm of sulfur oxidizing bacteria, starting-up and operating a bioscrubber treating H2S.  

UK PubMed Central (United Kingdom)

Development of an acclimatized SOB biofilm, startup and performance of a fixed bed bioscrubber packed with corrugated tube parts as a media having high specific surface area was investigated. Bioscrubber was a cylindrical Plexiglas air-and water-tight column with 10 L in working bed volume. Sludge from a tannery wastewater treatment plant was used as a seed for SOB separation, acclimation and enrichment. Enriched acclimatized SOB were applied as inoculum for biofilm development, which was carried out by recirculating the prepared microbial suspension through the bed. Thickness of the developed biofilm was 56 microm in which active acidophilic autotrophic H2S oxidizing bacteria were completely predominated. Activity measurements showed highest biodegradation rate of biofilm at liquid pH around 3. Due to employing an efficient specialized biofilm, startup period of the reactor was quite short and H2S removal efficiency just 12 h after starting up reached above of 92% and increased to 96% at day 3 of starting up while inlet H2S concentration gradually was increased to around 30 ppm. At the end of start up pH of the recycle liquid was modified to the optimal value of 3 +/- 0.5 in which biofilm demonstrated the highest activity in terms of OUR after which removal efficiency increased around 3% while other operating conditions were consistent. Furthermore, performance of the bioscrubber was evaluated at various inlet H2S concentrations ranging from 30 to 150 ppm(v). It was indicated that the inlet H2S concentrations in studied range did not affect the performance of the bioscrubber so that the removal efficiency of H2S was greater than 99.4% at all concentrations. These observations suggested that the development of an efficient specialized SOB biofilm on a media with high specific surface area will decrease the startup course and achieve high removal efficiency in the bioscrubber treating H2S. In addition, operation in acidic recycle liquid will overcome use of alkaline to adjust the pH, which reduce the operation cost of the control system.

Moussavi G; Naddafi K; Mesdaghinia A

2007-03-01

129

Carotenoid biomarkers as an imperfect reflection of the anoxygenic phototrophic community in meromictic Fayetteville Green Lake.  

UK PubMed Central (United Kingdom)

Organic biomarkers in marine sedimentary rocks hold important clues about the early history of Earth's surface environment. The chemical relicts of carotenoids from anoxygenic sulfur bacteria are of particular interest to geoscientists because of their potential to signal episodes of marine photic-zone euxinia such as those proposed for extended periods in the Proterozoic as well as brief intervals during the Phanerozoic. It is therefore critical to constrain the environmental and physiological factors that influence carotenoid production and preservation in modern environments. Here, we present the results of coupled pigment and nucleic acid clone library analyses from planktonic and benthic samples collected from a microbially dominated meromictic lake, Fayetteville Green Lake (New York). Purple sulfur bacteria (PSB) are abundant and diverse both in the water column at the chemocline and in benthic mats below oxygenated shallow waters, with different PSB species inhabiting the two environments. Okenone (from PSB) is an abundant carotenoid in both the chemocline waters and in benthic mats. Green sulfur bacteria and their primary pigment Bchl e are also represented in and below the chemocline. However, the water column and sediments are devoid of the green sulfur bacteria carotenoid isorenieratene. The unexpected absence of isorenieratene and apparent benthic production of okenone provide strong rationale for continued exploration of the microbial ecology of biomarker production in modern euxinic environments.

Meyer KM; Macalady JL; Fulton JM; Kump LR; Schaperdoth I; Freeman KH

2011-07-01

130

Photofermentative hydrogen production using purple non-sulfur bacteria Rhodobacter sphaeroides O.U.001 in an annular photobioreactor: A case study  

Energy Technology Data Exchange (ETDEWEB)

For meeting the increasing demand of energy, biohydrogen production is to be considered in higher yield. Biohydrogen can be produced both by dark and photofermentative process. In this study, the photofermentative pathway is followed by using DL malic acid (IUPAC name: 2-hydroxybutanedioic acid, molecular weight: 134.08744 g mol{sup -1}, molecular formula: C{sub 4}H{sub 6}O{sub 5}) as carbon source. Pure strain of purple non-sulfur (PNS) bacteria: Rhodobacter sphaeroides strain O.U.001 was studied to produce biohydrogen using the photobioreactor. The photobioreactor was constructed aiming the uniform light distribution. The objective of this study was to investigate the performance of 1 L annular photobioreactor operating in indoor conditions. The highest rate of hydrogen production was obtained at 92 h. In the designed photobioreactor, using Rhodobacter sphaeroides strain O.U.001 (initial DL malic acid concentration of 2.01 g L{sup -1}) at an initial pH of 6.8 {+-} 0.2, temperature 32 {+-} 2 C, inoculum volume 10% (v/v), inoculum age of 48 h, 250 rpm (rotation per minute) stirring and light intensity of 15 {+-} 1.1 W m{sup -2}, the average H{sub 2} production rate was about 6.5 {+-} 0.1 mL H{sub 2} h{sup -1} L{sup -1} media and yield 4.5 {+-} 0.05 mol of H{sub 2} mol{sup -1} of DL malic acid. Luedeking-Piret model was applied for the data fitting to determine the relationship between the cell growth and photofermentative hydrogen production. The photofermentative hydrogen production by this PNS bacterium was found to be microbial mixed growth associated function. (author)

Basak, Nitai [Department of Biotechnology, Dr.B.R.Ambedkar National Institute of Technology, Jalandhar 144011, Punjab (India); Fermentation Technology Laboratory, Department of Biotechnology, Indian Institute of Technology, Kharagpur 721302, West Bengal (India); Das, Debabrata [Fermentation Technology Laboratory, Department of Biotechnology, Indian Institute of Technology, Kharagpur 721302, West Bengal (India)

2009-06-15

131

Atmospheric sulfur  

Energy Technology Data Exchange (ETDEWEB)

Human activities are releasing great quantities of sulfur into the atmosphere, where it joins with naturally produced sulfur. Geochemists are trying to follow the evolution of sulfur compounds responsible for a variety of pollutions.

Bonsang, B. (Centre des Faibles Radioactivites, Gif-sur-Yvette (France))

1982-10-01

132

Isolation and endotoxin activities of lipopolysaccharides from cyanobacterial cultures and complex water blooms and comparison with the effects of heterotrophic bacteria and green alga.  

Science.gov (United States)

Massive cyanobacterial water blooms are serious environmental and health problems worldwide. While some cyanobacterial toxins such as peptide microcystins have been investigated extensively, other toxic components of cyanobacteria (e.g. lipopolysaccharides, LPS) are poorly understood. The present study characterized endotoxin activities of LPS isolated from (i) laboratory cyanobacterial cultures, (ii) cyanobacterial water bloom samples dominated by Microcystis sp., Planktothrix sp., Aphanizomenon sp. and Anabaena sp., (iii) heterotrophic Gram-negative bacteria Escherichia coli, Kluyvera intermedia, Pseudomonas putida and Pseudomonas fluorescens and (iv) green alga Pseudokirchneriella subcapitata. Toxicity results derived with Limulus amebocyte lysate assay (LAL-test) showed that endotoxin activities of LPS from both cyanobacteria and heterotrophic bacteria were comparable and the values were within a similar range (1 x 10(3)-1 x 10(6) Endotoxin Units, EU, per mg of isolated LPS). The highest activities among the cyanobacterial samples were observed in the Aphanizomenon sp. dominated water bloom. The results also suggest generally higher endotoxin activities in complex natural samples than in laboratory cyanobacterial cultures. Further, experiments with the eukaryotic green alga P. subcapitata demonstrated a need for careful purification of the LPS extracts prior to testing with the LAL assay as several contaminants may overestimate endotoxin activities. This study shows relatively high pyrogenicity of LPS from various cyanobacteria. Further research should focus on detailed toxicological and ecotoxicological characterization of LPS in massive cyanobacterial water blooms. PMID:17461433

Bernardová, Katerina; Babica, Pavel; Marsálek, Blahoslav; Bláha, Ludek

2008-01-01

133

New carotenoids from the thermophilic green sulfur bacterium Chlorobium tepidum: 1',2'-dihydro-gamma-carotene, 1',2'-dihydrochlorobactene, and OH-chlorobactene glucoside ester, and the carotenoid composition of different strains.  

UK PubMed Central (United Kingdom)

The complete carotenoid composition of the thermophilic green sulfur bacterium Chlorobium tepidum strain TNO was determined by spectroscopic methods. Major carotenoids were four kinds of carotenes: gamma-carotene, chlorobactene, and their 1',2'-dihydro derivatives (1',2'-dihydro-gamma-carotene and 1',2'-dihydrochlorobactene). In lesser amounts, hydroxyl gamma-carotene, hydroxyl chlorobactene, and their glucoside fatty acid esters were found. The only esterified fatty acid present was laurate, and OH-chlorobactene glucoside laurate is a novel carotenoid. In other strains of C. tepidum, the same carotenoids were found, but the composition varied from strain to strain. The overall pigment composition in cells of strain TNO was 4 mol carotenoids and 40 mol bacteriochlorophyll c per mol bacteriochlorophyll a. The effects of nicotine on carotenoid biosynthesis in C. tepidum differed from those in the thermophilic green nonsulfur bacterium Chloroflexus aurantiacus.

Takaichi S; Wang ZY; Umetsu M; Nozawa T; Shimada K; Madigan MT

1997-10-01

134

Characterization of Sulfur Compounds in Coffee Beans by Sulfur K-XANES Spectroscopy  

International Nuclear Information System (INIS)

In this 'feasibility study' the influence of roasting on the sulfur speciation in Mexican coffee beans was investigated by sulfur K-XANES Spectroscopy. Spectra of green and slightly roasted beans could be fitted to a linear combination of 'standard' reference spectra for biological samples, whereas longer roasting obviously involves formation of additional sulfur compounds in considerable amounts

2007-02-02

135

[Search for an optimal orientational ordering of Qy transition dipoles of subantennae molecules in superantenna of photosynthetic green bacteria. Model calculations  

UK PubMed Central (United Kingdom)

This work continues a series of our investigations on efficient strategies of functioning of natural light-harvesting antennae, initiated by our concept of rigorous optimization of photosynthetic apparatus structure by functional criterion. Using computer modeling for the functioning of the natural antennae, we suggested some basic principles for designing optimal model systems. Targeted searches for these principles in in vivo systems allowed us to recognize some of them in natural antennae. This work deals with the problem of the structure optimization of nonuniform superantennae of photosynthetic green bacteria. These superantennae consist of several uniform subantennae which produces a problem of their optimal coordination. In this work, we used mathematical modeling for the functioning of these natural superantennae to consider a possible way to optimize the superantenna structure using optimization of mutual spatial orientation of Qy transition dipoles of subantennae pigments. This allowed us to determine some modes of optimal orientational ordering of Qy transition dipoles of subantennae pigments in the model of the green bacterium Chloroflexus aurantiacus superantenna. It was shown that the optimal mutual orientation of Qy transition dipoles of subantennae pigments (resulting in stable minimizing of the energy transfer time within the superantenna and, as a consequence, in decrease in energy losses) ensures the high efficiency and stability of the superatenna functioning.

Zobova AV; Iakovlev AG; Taisova AS; Fetisova ZG

2009-05-01

136

Transposon Mutagenesis in Purple Sulfur Photosynthetic Bacteria: Identification of hypF, Encoding a Protein Capable of Processing [NiFe] Hydrogenases in ?, ?, and ? Subdivisions of the Proteobacteria  

Digital Repository Infrastructure Vision for European Research (DRIVER)

A random transposon-based mutagenesis system was optimized for the purple sulfur phototrophic bacterium Thiocapsa roseopersicina BBS. Screening for hydrogenase-deficient phenotypes resulted in the isolation of six independent mutants in a mini-Tn5 library. One of the mutations was in a gene showing ...

Fodor, Barna; Rákhely, Gábor; Kovács, Ákos T.; Kovács, Kornél L.

137

Electronic energy transfer involving carotenoid pigments in chlorosomes of two green bacteria: Chlorobium tepidum and Cholroflexus aurantiacus.  

UK PubMed Central (United Kingdom)

Electronic energy transfer processes in chlorosomes isolated from the green sulphur bacterium Chlorobium tepidum and from the green filamentous bacterium Chloroflexus aurantiacus have been investigated. Steady-state fluorescence excitation spectra and time-resolved triplet-minus-singlet (TmS) spectra, recorded at ambient temperature and under non-reducing or reducing conditions, are reported. The carotenoid (Car) pigments in both species transfer their singlet excitation to bacteriochlorophyll c (BChlc) with an efficiency which is high (between 0.5 and 0.8) but smaller than unity; BChlc and bacteriochlorophyll a (BChla) transfer their triplet excitation to the Car's with nearly 100% efficiency. The lifetime of the Car triplet states is approximately 3 micros, appreciably shorter than that of the Car triplets in the light-harvesting complex II (LHCII) in green plants and in other antenna systems. In both types of chlorosomes the yield of BChlc triplets (as judged from the yield of the Car triplets) remains insensitive to the redox conditions. In notable contrast the yield of BChlc singlet emission falls, upon a change from reducing to non-reducing conditions, by factors of 4 and 35 in Cfx. aurantiacus and Cb. tepidum, respectively. It is possible to account for these observations if one postulates that the bulk of the BChlc triplets originate either from a large BChlc pool which is essentially non-fluorescent and non-responsive to changes in the redox conditions, or as a result of a process which quenches BChlc singlet excitation and becomes more efficient under non-reducing conditions. In chlorosomes from Cfx. aurantiacus whose Car content is lowered, by hexane extraction, to 10% of the original value, nearly one-third of the photogenerated BChlc triplets still end up on the residual Car pigments, which is taken as evidence of BChlc-to-BChlc migration of triplet excitation; the BChlc triplets which escape rapid static quenching contribute a depletion signal at the long-wavelength edge of the Qy absorption band, indicating the existence of at least two pools of BChlc.

Melø TB; Frigaard NU; Matsuura K; Razi Naqvi K

2000-09-01

138

Communities of purple sulfur bacteria in a Baltic Sea coastal lagoon analyzed by puf LM gene libraries and the impact of temperature and NaCl concentration in experimental enrichment cultures.  

UK PubMed Central (United Kingdom)

Shallow coastal waters, where phototrophic purple sulfur bacteria (PSB) regularly form massive blooms, are subjected to massive diurnal and event-driven changes of physicochemical conditions including temperature and salinity. To analyze the ability of PSB to cope with these environmental factors and to compete in complex communities we have studied changes of the environmental community of PSB of a Baltic Sea lagoon under experimental enrichment conditions with controlled variation of temperature and NaCl concentration. For the first time, changes within a community of PSB were specifically analyzed using the photosynthetic reaction center genes pufL and M by RFLP and cloning experiments. The most abundant PSB phylotypes in the habitat were found along the NaCl gradient from freshwater conditions up to 7.5% NaCl. They were accompanied by smaller numbers of purple nonsulfur bacteria and aerobic anoxygenic phototrophic bacteria. Major components of the PSB community of the brackish lagoon were affiliated to PSB genera and species known as marine, halophilic or salt-tolerant, including species of M arichromatium, H alochromatium, T hiorhodococcus, A llochromatium, T hiocapsa, T hiorhodovibrio, and T hiohalocapsa. A dramatic shift occurred at elevated temperatures of 41 and 44°C when M arichromatium gracile became most prominent which was not detected at lower temperatures.

Tank M; Blümel M; Imhoff JF

2011-12-01

139

Safe use of genetically modified lactic acid bacteria in food: Bridging the gap between consumers, green groups, and industry  

Scientific Electronic Library Online (English)

Full Text Available Abstract in english Within the European Union (EU), the use of genetically modified organisms (GMOs) in food production is not widely applied and accepted. In contrast to the United States of America, the current EU legislation limits the introduction of functional foods derived from GMOs that may bring a clear benefit to the consumer. Genetically modified lactic acid bacteria (GM-LAB) can be considered as a different class of GMOs, and the European Union is preparing regulations for the ris (more) k assessment of genetically modified microorganisms. Since these procedures are not yet implemented, the current risk assessment procedure is shared for GMOs derived from micro organisms, plants, or animals. At present, the use of organisms in food production that have uncontrolled genetic alterations made through random mutagenesis, is permitted, while similar applications with organisms that have controlled genetic alterations are not allowed. The current paper reviews the opportunities that genetically modified lactic acid bacteria may offer the food industry and the consumer. An objective risk profile is described for the use of GM-LAB in food production. To enhance the introduction of functional foods with proven health claims it is proposed to adapt the current safety assessment procedures for (GM)-LAB and suggestions are made for the related cost accountability. A qualified presumption of safety as proposed by SANCO (EU SANCO 2003), based on taxonomy and on the history of safe use of LAB applied in food, could in the near future be applied to any kind of LAB or GM-LAB provided that a series of modern profiling methods are used to verify the absence of unintended effects of altered LAB that may cause harm to the health of the consumer.

Sybesma, Wilbert; Hugenholtz, Jeroen; de Vos, Willem M.; Smid, Eddy J.

2006-07-01

140

Novel in vitro model for assessing susceptibility of synthetic hernia repair meshes to Staphylococcus aureus infection using green fluorescent protein-labeled bacteria and modern imaging techniques.  

UK PubMed Central (United Kingdom)

BACKGROUND: Mesh infection complicating hernia repair is a major cause of patient morbidity and results in substantial healthcare expenditures. The various constructs of prosthetic mesh may alter the ability of bacteria to attach and form a biofilm. Few data exist evaluating biofilm formation. Using the Maestro in-Vivo Imaging System (CRi, Inc., Woburn, MA) to detect green fluorescent protein (GFP)-expressing Staphylococcus aureus, we studied the ability of synthetic mesh to withstand bacterial biofilm formation in an in vitro model. METHODS: We included four meshes: Polypropylene (PP), polypropylene/expanded PTFE (PX), compressed PTFE (cPTFE), and polyester/polyethylene glycol and collagen hydrogel (PE). Five samples of each mesh were exposed to GFP-expressing S. aureus for 18?h at 37°C. Next, green fluorescence was measured using the Maestro Imaging System, with the results expressed in relative fluorescence units (RFU), subtracting the fluorescence of uninfected mesh (control). Each mesh subsequently underwent sonication and quantitative culture of the released bacteria, with the results expressed in colony-forming units (CFU). Analysis of variance was performed to compare the mean values for the different meshes. RESULTS: There was a statistically significant difference in bacterial fluorescence for the four meshes: PE (49.9?±?25.5 [standard deviation] RFU), PX (30.8?±?9.4 RFU), cPTFE (10.1?±?4.0 RFU), and PP (5.8?±?7.5 RFU)(p?=?0.001). Bacterial counts also were significantly different: PE (2.2?×?10(8) CFU), PX (8.6?×?10(7) CFU), cPTFE (3.7?×?10(7) CFU), and PP (9.1?×?10(7) CFU)(p?

Halaweish I; Harth K; Broome AM; Voskerician G; Jacobs MR; Rosen MJ

2010-10-01

 
 
 
 
141

Bacterial intracellular sulfur globules: structure and function.  

UK PubMed Central (United Kingdom)

Bacteria that oxidize reduced sulfur compounds like H2S often transiently store sulfur in protein membrane-bounded intracellular sulfur globules; intracellular in this case meaning found inside the cell wall. The cultured bacteria that form these globules are primarily phylogenetically classified in the Proteobacteria and are chemotrophic or photoautotrophic. The current model organism is the purple sulfur bacterium Allochromatium vinosum. Research on this bacterium has provided the groundwork for understanding the protein membranes and the sulfur contents of globules. In addition, it has demonstrated the importance of different genes (e.g. sulfur oxidizing, sox) in their formation and in the final oxidation of sulfur in the globules to sulfate (e.g. dissimilatory sulfite reductase, dsr). Pursuing the characteristics of other intracellular sulfur globule-forming bacteria through genomics, transcriptomics and proteomics will eventually lead to a complete picture of their formation and breakdown. There will be commonality to some of the genetic, physiological and morphological characteristics involved in intracellular sulfur globules of different bacteria, but there will likely be some surprises as well.

Maki JS

2013-01-01

142

Biological studies of hot springs. Algae and bacteria living in extreme environments; Onsen no seibutsugaku. Tokushu kankyo ni seisokusuru sorui to saikinrui  

Energy Technology Data Exchange (ETDEWEB)

This paper reviews studies on algae and bacteria living in extreme environments, such as hot springs. Most of algae living in extreme environments are blue-green algae. Species of algae living in hot springs reduce their kinds with increasing temperature, and reduce them drastically in the temperature range over 60 centigrade. Among algae living in hot springs, blue-green algae with acidophilic and thermophilic properties are elucidated. On the other hand, bacteria are classified into bacteria living in high temperature and strongly acidic environment, bacteria living in high temperature and nearly neutral environment, and bacteria living in relatively low temperature and strongly acidic environment. For the bacteria living in high temperature and strongly acidic environment, Bacillus genus bacteria and Archaebacteria are elucidated. For the bacteria living in high temperature and neutral environment, Bacillus genus bacteria, Thermus genus bacteria, Archaebacteria, and sulfur grass are elucidated. For the bacteria living in lower temperature and strongly acidic environment, Thiobacillus genus bacteria are elucidated. 174 refs., 11 figs., 5 tabs.

Sugimori, K. [Toho University, Tokyo (Japan). School of Medicine

1994-12-31

143

Biomonitoring marine habitats in reference to antibiotic resistant bacteria and ampicillin resistance determinants from oviductal fluid of the nesting green sea turtle, Chelonia mydas.  

UK PubMed Central (United Kingdom)

During the egg-laying process, oviductal fluid was collected using a non-invasive procedure from the cloacal vent of the green turtles. Forty-two independent isolates of antibiotic-resistant bacteria from 11 genera were obtained from 20 turtles during nesting. The dominant isolate was Citrobacter (52.4%), followed by Pseudomonas, Proteus, Enterobacter, Salmonella, Escherichia coli, Shigella, Edwardsiella, Morganella, Providencia and Arcomobacter. Most of the isolates were resistant to ampicillin. Ampicillin-resistant isolates showed variations in their resistance for the following classes of ?-lactamases: extended-spectrum ?-lactamases (EBSLs), AmpC type ?-lactamases C (AmpC), and screen-positive ?-lactamase. None of the isolates produced metallo ?-lactamase. Some ampicillin-resistant genes were detected by multiplex polymerase chain reaction (PCR) only. Inhibitor based test (IBT) categorized some isolates as AmpC ?-lactamase producers. ?-Lactamase genes were detected from a few strains. The sequencing of those genes revealed the presence of cephamycinase (CMY) and AmpC ?-lactamases. The oviductal fluid was used in this study as a source of bacterial antibiotic-resistant determinants for biomonitoring marine turtles exposed to contaminated effluents. This data can be of value in understanding the decline of this endangered species as a result of exposure to marine pollution which is threatening their survival.

Al-Bahry SN; Al-Zadjali MA; Mahmoud IY; Elshafie AE

2012-06-01

144

Biomonitoring marine habitats in reference to antibiotic resistant bacteria and ampicillin resistance determinants from oviductal fluid of the nesting green sea turtle, Chelonia mydas.  

Science.gov (United States)

During the egg-laying process, oviductal fluid was collected using a non-invasive procedure from the cloacal vent of the green turtles. Forty-two independent isolates of antibiotic-resistant bacteria from 11 genera were obtained from 20 turtles during nesting. The dominant isolate was Citrobacter (52.4%), followed by Pseudomonas, Proteus, Enterobacter, Salmonella, Escherichia coli, Shigella, Edwardsiella, Morganella, Providencia and Arcomobacter. Most of the isolates were resistant to ampicillin. Ampicillin-resistant isolates showed variations in their resistance for the following classes of ?-lactamases: extended-spectrum ?-lactamases (EBSLs), AmpC type ?-lactamases C (AmpC), and screen-positive ?-lactamase. None of the isolates produced metallo ?-lactamase. Some ampicillin-resistant genes were detected by multiplex polymerase chain reaction (PCR) only. Inhibitor based test (IBT) categorized some isolates as AmpC ?-lactamase producers. ?-Lactamase genes were detected from a few strains. The sequencing of those genes revealed the presence of cephamycinase (CMY) and AmpC ?-lactamases. The oviductal fluid was used in this study as a source of bacterial antibiotic-resistant determinants for biomonitoring marine turtles exposed to contaminated effluents. This data can be of value in understanding the decline of this endangered species as a result of exposure to marine pollution which is threatening their survival. PMID:22406312

Al-Bahry, S N; Al-Zadjali, M A; Mahmoud, I Y; Elshafie, A E

2012-03-08

145

Microbiological study of naturally fermented Algerian green olives: isolation and identification of lactic acid bacteria and yeasts along with the effects of brine solutions obtained at the end of olive fermentation on Lactobacillus plantarum...  

Directory of Open Access Journals (Sweden)

Full Text Available The microflora of naturally fermented green olives produced in Western Algeria was studied over 15, 60 and 90 day fermentation periods. Different microorganisms (aerobic bacteria, coliforms, staphylococci, lactic acid bacteria, lactobacilli, enterococci, yeasts, psychrotrophs and lipolytic bacteria) were recorded at 15 and 60 days of fermentation. After 90 days (pH 4.40) of fermentation, the lactic acid bacteria population became dominant and persisted together with yeasts throughout the fermentation period. The lactic acid bacteria isolated (343 isolates) were identified as L. casei, L. rhamnosus, L. paracasei, L. plantarum, L. lactis subsp. lactis, E. faecalis, E. faecium and E. durans. The dominant species was L. plantarum. Yeasts were isolated from all samples (32 isolates) and were identified as Saccharomyces cerevisiae or Candida parapsilosis. Also, in this study we reported that brine solutions obtained at the end of olive fermentation were able to stimulate the growth of several L. plantarum strainsLa microflora de las aceitunas verdes fermentadas naturalmente elaboradas en Argelia Occidental fue estudiada en períodos de fermentación de 15, 60 y 90 días. Diferentes microorganismos (bacterias aeróbicas, coliformes, estafilococos, bacterias del ácido láctico, lactobacilos, enterococos, levaduras, psicotrofos y bacterias lipolíticas) fueron detectados a los 15 y 60 días de fermentación. Después de 90 días de fermentación (pH 4.40), la población de bacterias lácticas se hizo dominante y persistió junto con las levaduras a lo largo de todo el proceso. Las bacterias lácticas aisladas (343) fueron identificadas como L. casei, L. rhamnosus, L. paracasei, L. plantarum, L. lactis subsp. lactis, E. faecalis, E. faecium y E. durans. La especie dominante fue L. plantarum. Las levaduras aisladas (32) de todas las muestras fueron identificadas como Saccharomyces cerevisiae o Candida parapsilosis. También se recoge en este estudio que las soluciones de salmuera obtenidas al final de fermentación de aceitunas verdes fueron capaces de estimular el crecimiento de varias cepas de L. plantarum.

Mourad, Kacem; Nour-Eddine, Karam

2006-01-01

146

Sulfite oxidation in the purple sulfur bacterium Allochromatium vinosum: Identification of SoeABC as a major player and relevance of SoxYZ in the process.  

UK PubMed Central (United Kingdom)

In phototrophic sulfur bacteria, sulfite is a well-established intermediate during reduced sulfur compound oxidation. Sulfite is generated in the cytoplasm by the reverse acting dissimilatory sulfite reductase DsrAB. Many purple sulfur bacteria can even use externally available sulfite as photosynthetic electron donor. Nevertheless, the exact mode of sulfite oxidation in these organisms is a long-standing enigma. Indirect oxidation in the cytoplasm via adenosine-5'-phosphosulfate (APS) catalyzed by APS reductase and ATP sulfurylase is neither generally present nor essential. The inhibition of sulfite oxidation by tungstate in the model organism Allochromatium vinosum indicated the involvement of a molybdoenzyme, but homologues of the periplasmic molybdopterin-containing SorAB or SorT sulfite dehydrogenases are not encoded in genome-sequenced purple or green sulfur bacteria. On the other hand, genes for a membrane-bound polysulfide reductase-like iron-sulfur molybdoprotein (SoeABC) are universally present. The catalytic subunit of the protein is predicted to be oriented towards the cytoplasm. We compared the sulfide and sulfite oxidizing capabilities of Alc. vinosum wild type, single mutants deficient in SoeABC or APS reductase and the respective double mutant and were thus able to prove that SoeABC is the major sulfite-oxidizing enzyme in Alc. vinosum and probably also in other phototrophic sulfur bacteria. The genes also occur in a large number of chemotrophs pointing at a general importance of SoeABC for sulfite oxidation in the cytoplasm. Furthermore, we show that the periplasmic sulfur substrate-binding protein SoxYZ is needed in parallel to the cytoplasmic enzymes for effective sulfite oxidation in Alc. vinosum and provide a model for the interplay between these systems despite their localization in different cellular compartments.

Dahl C; Franz B; Hensen D; Kesselheim A; Zigann R

2013-09-01

147

Occurrence of hydrogenases in cyanobacteria and anoxygenic photosynthetic bacteria: implications for the phylogenetic origin of cyanobacterial and algal hydrogenases.  

UK PubMed Central (United Kingdom)

Hydrogenases are important enzymes in the energy metabolism of microorganisms. Therefore, they are widespread in prokaryotes. We analyzed the occurrence of hydrogenases in cyanobacteria and deduced a FeFe-hydrogenase in three different heliobacterial strains. This allowed the first phylogenetic analysis of the hydrogenases of all five major groups of photosynthetic bacteria (heliobacteria, green nonsulfur bacteria, green sulfur bacteria, photosynthetic proteobacteria, and cyanobacteria). In the case of both hydrogenases found in cyanobacteria (uptake and bidirectional), the green nonsulfur bacterium Chloroflexus aurantiacus was found to be the closest ancestor. Apart from a close relation between the archaebacterial and the green sulfur bacterial sulfhydrogenase, we could not find any evidence for horizontal gene transfer. Therefore, it would be most parsimonious if a Chloroflexus-like bacterium was the ancestor of Chloroflexus aurantiacus and cyanobacteria. After having transmitted both hydrogenase genes vertically to the different cyanobacterial species, either no, one, or both enzymes were lost, thus producing the current distribution. Our data and the available data from the literature on the occurrence of cyanobacterial hydrogenases show that the cyanobacterial uptake hydrogenase is strictly linked to the occurrence of the nitrogenase. Nevertheless, we did identify a nitrogen-fixing Synechococcus strain without an uptake hydrogenase. Since we could not find genes of a FeFe-hydrogenase in any of the tested cyanobacteria, although strains performing anoxygenic photosynthesis were also included in the analysis, a cyanobacterial origin of the contemporary FeFe-hydrogenase of algal plastids seems unlikely.

Ludwig M; Schulz-Friedrich R; Appel J

2006-12-01

148

Effect of dietary inorganic sulfur level on growth performance, fecal composition, and measures of inflammation and sulfate-reducing bacteria in the intestine of growing pigs.  

Science.gov (United States)

Two experiments investigated the impact of dietary inorganic S on growth performance, intestinal inflammation, fecal composition, and the presence of sulfate-reducing bacteria (SRB). In Exp. 1, individually housed pigs (n = 42; 13.8 kg) were fed diets containing 2,300 or 2,100 mg/kg of S for 24 d. Decreasing dietary S had no effect on ADG, ADFI, or G:F. In Exp. 2, pigs (n = 64; 13.3 kg) were fed diets containing 0, 0.625, 1.25, 2.5, or 5.0% CaSO(4), thereby increasing dietary S from 2,900 to 12,100 mg/kg. Two additional diets were fed to confirm the lack of an impact due to feeding low dietary S on pig performance and to determine if the increased Ca and P content in the diets containing CaSO(4) had an impact on growth performance. Pigs were fed for 35 d. Ileal tissue, ileal mucosa, and colon tissue were harvested from pigs fed the 0 and 5% CaSO(4) diets (low-S and high-S, respectively) to determine the impact of dietary S on inflammation-related mRNA, activity of mucosal alkaline phosphatase and sucrase, and pathways of inflammatory activation. Real-time PCR was used to quantify SRB in ileal and colon digesta samples and feces. Fecal pH, sulfide, and ammonia concentrations were also determined. There was no impact on growth performance in pigs fed the diet reduced in dietary S or by the increase of dietary Ca and P. Increasing dietary S from 2,900 to 12,100 mg/kg had a linear (P < 0.01) effect on ADG and a cubic effect (P < 0.05) on ADFI and G:F. Real-time reverse-transcription PCR analysis revealed that pigs fed high-S increased (P < 0.05) the relative abundance of intracellular adhesion molecule-1, tumor necrosis factor-?, and suppressor of cytokine signaling-3 mRNA, and tended (P = 0.09) to increase the relative abundance of IL-6 mRNA in ileal tissue. Likewise, pigs fed high-S had reduced (P < 0.05) abundance of nuclear factor of ? light polypeptide gene enhancer in B-cells inhibitor-? and increased (P < 0.05) phospho-p44/p42 mitogen-activated protein kinase in ileal tissue, but there was no effect of dietary S on mucosal alkaline phosphatase or sucrase activity. Pigs fed the high-S diet had decreased (P < 0.05) total bacteria in ileal digesta, but increased (P < 0.05) prevalence of SRB in colon contents. Fecal sulfide was increased (P < 0.05) and fecal pH was deceased (P < 0.05) in pigs fed high-S. The data indicate that growing pigs can tolerate relatively high amounts of dietary inorganic S, but high dietary S content alters inflammatory mediators and intestinal bacteria. PMID:20952529

Kerr, B J; Weber, T E; Ziemer, C J; Spence, C; Cotta, M A; Whitehead, T R

2010-10-15

149

Effect of dietary inorganic sulfur level on growth performance, fecal composition, and measures of inflammation and sulfate-reducing bacteria in the intestine of growing pigs.  

UK PubMed Central (United Kingdom)

Two experiments investigated the impact of dietary inorganic S on growth performance, intestinal inflammation, fecal composition, and the presence of sulfate-reducing bacteria (SRB). In Exp. 1, individually housed pigs (n = 42; 13.8 kg) were fed diets containing 2,300 or 2,100 mg/kg of S for 24 d. Decreasing dietary S had no effect on ADG, ADFI, or G:F. In Exp. 2, pigs (n = 64; 13.3 kg) were fed diets containing 0, 0.625, 1.25, 2.5, or 5.0% CaSO(4), thereby increasing dietary S from 2,900 to 12,100 mg/kg. Two additional diets were fed to confirm the lack of an impact due to feeding low dietary S on pig performance and to determine if the increased Ca and P content in the diets containing CaSO(4) had an impact on growth performance. Pigs were fed for 35 d. Ileal tissue, ileal mucosa, and colon tissue were harvested from pigs fed the 0 and 5% CaSO(4) diets (low-S and high-S, respectively) to determine the impact of dietary S on inflammation-related mRNA, activity of mucosal alkaline phosphatase and sucrase, and pathways of inflammatory activation. Real-time PCR was used to quantify SRB in ileal and colon digesta samples and feces. Fecal pH, sulfide, and ammonia concentrations were also determined. There was no impact on growth performance in pigs fed the diet reduced in dietary S or by the increase of dietary Ca and P. Increasing dietary S from 2,900 to 12,100 mg/kg had a linear (P < 0.01) effect on ADG and a cubic effect (P < 0.05) on ADFI and G:F. Real-time reverse-transcription PCR analysis revealed that pigs fed high-S increased (P < 0.05) the relative abundance of intracellular adhesion molecule-1, tumor necrosis factor-?, and suppressor of cytokine signaling-3 mRNA, and tended (P = 0.09) to increase the relative abundance of IL-6 mRNA in ileal tissue. Likewise, pigs fed high-S had reduced (P < 0.05) abundance of nuclear factor of ? light polypeptide gene enhancer in B-cells inhibitor-? and increased (P < 0.05) phospho-p44/p42 mitogen-activated protein kinase in ileal tissue, but there was no effect of dietary S on mucosal alkaline phosphatase or sucrase activity. Pigs fed the high-S diet had decreased (P < 0.05) total bacteria in ileal digesta, but increased (P < 0.05) prevalence of SRB in colon contents. Fecal sulfide was increased (P < 0.05) and fecal pH was deceased (P < 0.05) in pigs fed high-S. The data indicate that growing pigs can tolerate relatively high amounts of dietary inorganic S, but high dietary S content alters inflammatory mediators and intestinal bacteria.

Kerr BJ; Weber TE; Ziemer CJ; Spence C; Cotta MA; Whitehead TR

2011-02-01

150

Marine Bacteria from Danish Coastal Waters Show Antifouling Activity against the Marine Fouling Bacterium Pseudoalteromonas sp. Strain S91 and Zoospores of the Green Alga Ulva australis Independent of Bacteriocidal Activity  

DEFF Research Database (Denmark)

The aims of this study were to determine if marine bacteria from Danish coastal waters produce antifouling compounds and if antifouling bacteria could be ascribed to specific niches or seasons. We further assess if antibacterial effect is a good proxy for antifouling activity. We isolated 110 bacteria with anti-Vibrio activity from different sample types and locations during a 1-year sampling from Danish coastal waters. The strains were identified as Pseudoalteromonas, Phaeobacter, and Vibrionaceae based on phenotypic tests and partial 16S rRNA gene sequence similarity. The numbers of bioactive bacteria were significantly higher in warmer than in colder months. While some species were isolated at all sampling locations, others were niche specific. We repeatedly isolated Phaeobacter gallaeciensis at surfaces from one site and Pseudoalteromonas tunicata at two others. Twenty-two strains, representing the major taxonomic groups, different seasons, and isolation strategies, were tested for antiadhesive effect against the marine biofilm-forming bacterium Pseudoalteromonas sp. strain S91 and zoospores of the green alga Ulva australis. The antiadhesive effects were assessed by quantifying the number of strain S91 or Ulva spores attaching to a preformed biofilm of each of the 22 strains. The strongest antifouling activity was found in Pseudoalteromonas strains. Biofilms of Pseudoalteromonas piscicida, Pseudoalteromonas tunicata, and Pseudoalteromonas ulvae prevented Pseudoalteromonas S91 from attaching to steel surfaces. P. piscicida killed S91 bacteria in the suspension cultures, whereas P. tunicata and P. ulvae did not; however, they did prevent adhesion by nonbactericidal mechanism(s). Seven Pseudoalteromonas species, including P. piscicida and P. tunicata, reduced the number of settling Ulva zoospores to less than 10% of the number settling on control surfaces. The antifouling alpP gene was detected only in P. tunicata strains (with purple and yellow pigmentation), so other compounds/mechanisms must be present in theother Pseudoalteromonas strains with antifouling activity.

Bernbom, Nete; Ng, Yoke Yin

2011-01-01

151

Marine bacteria from Danish coastal waters show antifouling activity against the marine fouling bacterium Pseudoalteromonas sp. strain S91 and zoospores of the green alga Ulva australis independent of bacteriocidal activity.  

UK PubMed Central (United Kingdom)

The aims of this study were to determine if marine bacteria from Danish coastal waters produce antifouling compounds and if antifouling bacteria could be ascribed to specific niches or seasons. We further assess if antibacterial effect is a good proxy for antifouling activity. We isolated 110 bacteria with anti-Vibrio activity from different sample types and locations during a 1-year sampling from Danish coastal waters. The strains were identified as Pseudoalteromonas, Phaeobacter, and Vibrionaceae based on phenotypic tests and partial 16S rRNA gene sequence similarity. The numbers of bioactive bacteria were significantly higher in warmer than in colder months. While some species were isolated at all sampling locations, others were niche specific. We repeatedly isolated Phaeobacter gallaeciensis at surfaces from one site and Pseudoalteromonas tunicata at two others. Twenty-two strains, representing the major taxonomic groups, different seasons, and isolation strategies, were tested for antiadhesive effect against the marine biofilm-forming bacterium Pseudoalteromonas sp. strain S91 and zoospores of the green alga Ulva australis. The antiadhesive effects were assessed by quantifying the number of strain S91 or Ulva spores attaching to a preformed biofilm of each of the 22 strains. The strongest antifouling activity was found in Pseudoalteromonas strains. Biofilms of Pseudoalteromonas piscicida, Pseudoalteromonas tunicata, and Pseudoalteromonas ulvae prevented Pseudoalteromonas S91 from attaching to steel surfaces. P. piscicida killed S91 bacteria in the suspension cultures, whereas P. tunicata and P. ulvae did not; however, they did prevent adhesion by nonbactericidal mechanism(s). Seven Pseudoalteromonas species, including P. piscicida and P. tunicata, reduced the number of settling Ulva zoospores to less than 10% of the number settling on control surfaces. The antifouling alpP gene was detected only in P. tunicata strains (with purple and yellow pigmentation), so other compounds/mechanisms must be present in the other Pseudoalteromonas strains with antifouling activity.

Bernbom N; Ng YY; Kjelleberg S; Harder T; Gram L

2011-12-01

152

Biochemistry of Dissimilatory Sulfur Oxidation  

Energy Technology Data Exchange (ETDEWEB)

The long term goals of this research were to define the substrate oxidation pathways, the electron transport mechanisms, and the modes of energy conservation employed during the dissimilatory oxidation of sulfur practiced by various species of the thiobacilli. Specific adhesion of the thiobacilli to elemental sulfur was studied by electrical impedance, dynamic light scattering, laser Doppler velocimetry, and optical trapping methods. The conclusion is that the thiobacilli appear to express specific receptors that enable the bacteria to recognize and adhere to insoluble sulfur. The enzyme tetrathionate oxidase was purified from two species of the thiobacilli. Extensive structural and functional studies were conducted on adenosine 5'-phosphosulfate reductase purified from cell-free extracts of Thiobacillus denitrificans. The kinetic mechanism of rhodanese was studied.

Blake II, R.

2003-05-30

153

Bacteria: Fossil Record  

Science.gov (United States)

This description of the fossil record of bacteria focuses on one particular group of bacteria, the cyanobacteria or blue-green algae, which have left a fossil record that extends far back into the Precambrian. The oldest cyanobacteria-like fossils known are nearly 3.5 billion years old and are among the oldest fossils currently known. Cyanobacteria are larger than most bacteria and may secrete a thick cell wall. More importantly, cyanobacteria may form large layered structures, called stromatolites (if more or less dome-shaped) or oncolites (if round). The site also refers to pseudomorphs of pyrite and siderite, and a group of bacteria known as endolithic. Two links are available for more information. One provides information on the discovery of possible remains of bacteria-like organisms on a meteorite from Mars and the other has a research report on fossilized filamentous bacteria and other microbes, found in Cretaceous amber.

154

Global biogeochemical sulfur cycle  

Energy Technology Data Exchange (ETDEWEB)

The global sulfur balance in the pedosphere, atmosphere and hydrosphere is studied. Flowsheets for sulfur emission and deposition are explained; sulfur reserves and global sulfur distribution are calculated in Mt and given in tables. The global sulfur cycle is divided into the anthropogene cycle (comprising sulfur dioxide emission by fossil-fuel combustion), the geophysical cycle (comprising emission of sulfur dioxide from volcanic activity as well as sulfate from seaspray, rock weathering and river flow), and the biological sulfur cycle (processes of plants and microorganisms). Cycles of emission and deposition are established. Sulfur quantities for the atmospheric sulfur balance are estimated. The global sulfur balance is assessed for the time pre-1900 (natural cycle) and present time (1975). Other estimates of sulfur balance values are discussed. 69 references.

Moeller, D.

1985-01-01

155

Heterogeneous photocatalytic reactions of sulfur aromatic compounds.  

Science.gov (United States)

Sulfur aromatic compounds, such as mono-, di-, tri-, and tetraalkyl-substituted thiophene, benzothiophenes, dibenzothiophenes, are the molecular components of many fossils (petroleum, oil shale, tar sands, bitumen). Structural units of natural, cross-linked heteroaromatic polymers present in brown coals, turf, and soil are similar to those of sulfur aromatic compounds. Many sulfur aromatic compounds are found in the streams of petroleum refining and upgrading (naphthas, gas oils) and in the consumer products (gasoline, diesel, jet fuels, heating fuels). Besides fossils, the structural fragments of sulfur aromatic compounds are present in molecules of certain organic semiconductors, pesticides, small molecule drugs, and in certain biomolecules present in human body (pheomelanin pigments). Photocatalysis is the frontier area of physical chemistry that studies chemical reactions initiated by absorption of photons by photocatalysts, that is, upon electronic rather than thermal activation, under "green" ambient conditions. This review provides systematization and critical review of the fundamental chemical and physicochemical information on heterogeneous photocatalysis of sulfur aromatic compounds accumulated in the last 20-30 years. Specifically, the following topics are covered: physicochemical properties of sulfur aromatic compounds, major classes of heterogeneous photocatalysts, mechanisms and reactive intermediates of photocatalytic reactions of sulfur aromatic compounds, and the selectivity of these reactions. Quantum chemical calculations of properties and structures of sulfur aromatic compounds, their reactive intermediates, and the structure of adsorption complexes formed on the surface of the photocatalysts are also discussed. PMID:21809426

Samokhvalov, Alexander

2011-08-01

156

Heterogeneous photocatalytic reactions of sulfur aromatic compounds.  

UK PubMed Central (United Kingdom)

Sulfur aromatic compounds, such as mono-, di-, tri-, and tetraalkyl-substituted thiophene, benzothiophenes, dibenzothiophenes, are the molecular components of many fossils (petroleum, oil shale, tar sands, bitumen). Structural units of natural, cross-linked heteroaromatic polymers present in brown coals, turf, and soil are similar to those of sulfur aromatic compounds. Many sulfur aromatic compounds are found in the streams of petroleum refining and upgrading (naphthas, gas oils) and in the consumer products (gasoline, diesel, jet fuels, heating fuels). Besides fossils, the structural fragments of sulfur aromatic compounds are present in molecules of certain organic semiconductors, pesticides, small molecule drugs, and in certain biomolecules present in human body (pheomelanin pigments). Photocatalysis is the frontier area of physical chemistry that studies chemical reactions initiated by absorption of photons by photocatalysts, that is, upon electronic rather than thermal activation, under "green" ambient conditions. This review provides systematization and critical review of the fundamental chemical and physicochemical information on heterogeneous photocatalysis of sulfur aromatic compounds accumulated in the last 20-30 years. Specifically, the following topics are covered: physicochemical properties of sulfur aromatic compounds, major classes of heterogeneous photocatalysts, mechanisms and reactive intermediates of photocatalytic reactions of sulfur aromatic compounds, and the selectivity of these reactions. Quantum chemical calculations of properties and structures of sulfur aromatic compounds, their reactive intermediates, and the structure of adsorption complexes formed on the surface of the photocatalysts are also discussed.

Samokhvalov A

2011-11-01

157

Enhancement of Copper Availability and Microbial Community Changes in Rice Rhizospheres Affected by Sulfur  

Directory of Open Access Journals (Sweden)

Full Text Available The role of sulfur on the availability of Cu and the bacterial community in rice rhizospheres was investigated by pot experiments. With sulfur addition, pH in rhizosphere soil decreased and Mg(NO3)2 extractable Cu increased significantly. The bacterial community composition also changed with sulfur addition. Some specific clones having high similarity to Thiobacillus, which indicated that sulfur oxidation in the rice rhizosphere could increase the availability of Cu. These results suggested that sulfur source which could provide substrate to sulfur oxidizing bacteria and enhance the availability of Cu was not a suitable sulfur fertilizer for Cu polluted soil.

Ji-Yan Shi; Hui-Rong Lin; Xiao-Feng Yuan; Xin-Cai Chen; Chao-Feng Shen; Ying-Xu Chen

2011-01-01

158

Uses of lunar sulfur  

Energy Technology Data Exchange (ETDEWEB)

Sulfur and sulfur compounds have a wide range of applications for their fluid, electrical, chemical and biochemical properties. Although low in abundance on the Moon (/approximately/0.1% in mare soils), sulfur is surface-correlated and relatively extractable. Co-production of sulfur during oxygen extraction from ilmenite-rich soils could yield sulfur in masses up to 10% of the mass of oxygen produced. Sulfur deserves serious consideration as a lunar resource. 29 refs., 3 figs.

Vaniman, D.T.; Pettit, D.R.; Heiken, G.

1988-01-01

159

Sulfuric acid-sulfur heat storage cycle  

Energy Technology Data Exchange (ETDEWEB)

A method of storing heat is provided utilizing a chemical cycle which interconverts sulfuric acid and sulfur. The method can be used to levelize the energy obtained from intermittent heat sources, such as solar collectors. Dilute sulfuric acid is concentrated by evaporation of water, and the concentrated sulfuric acid is boiled and decomposed using intense heat from the heat source, forming sulfur dioxide and oxygen. The sulfur dioxide is reacted with water in a disproportionation reaction yielding dilute sulfuric acid, which is recycled, and elemental sulfur. The sulfur has substantial potential chemical energy and represents the storage of a significant portion of the energy obtained from the heat source. The sulfur is burned whenever required to release the stored energy. A particularly advantageous use of the heat storage method is in conjunction with a solar-powered facility which uses the Bunsen reaction in a water-splitting process. The energy storage method is used to levelize the availability of solar energy while some of the sulfur dioxide produced in the heat storage reactions is converted to sulfuric acid in the Bunsen reaction.

Norman, John H. (LaJolla, CA)

1983-12-20

160

Microbiological disproportionation of inorganic sulfur compounds  

DEFF Research Database (Denmark)

The disproportionation of inorganic sulfur intermediates at moderate temperatures (0-80 °C) is a microbiologically catalyzed chemolithotrophic process in which compounds like elemental sulfur, thiosulfate, and sulfite serve as both electron donor and acceptor, and generate hydrogen sulfide and sulfate. Thus the overall process is comparable to the fermentation of organic compounds such as glucose and is consequently often described as 'inorganic fermentation'. The process is primarily carried out by microorganisms with phylogenetic affiliation to the so called sulfate-reducing bacteria within the delta subclass of Proteobacteria. The organisms grow with sulfate as their external electron acceptor and low-molecular weight organic compounds or hydrogen as energy sources. Studies of the biochemistry of a few isolates indicate that the disproportionating microbes reverse the sulfate reduction pathway during disproportionation. However, investigations with elemental sulfur disproportionating bacteria present evidence for an alternative pathway involving the enzyme sulfite-oxidoreductase, an enzyme that has hitherto only been reported participating in the oxidation of sulfite in aerobic or phototrophic sulfide oxidizers. Investigations bridging geology and microbiology have found strong evidence for disproportionating bacteria participating in and enhancing the rate at which pyrite forms and being partly responsible for the isotopic signatures of sulfidic minerals in recent and old sediments. New results indicate that elemental sulfur disproportionating microbes can be traced back in time as long as 3.5 billion years and elemental sulfur disproportionation would thus be one the oldest biological processes on Earth.

Finster, Kai

2008-01-01

 
 
 
 
161

BACTERIAL CELLULOSE BASED 'GREEN' COMPOSITES  

UK PubMed Central (United Kingdom)

'Green' composites are fabricated using resins, such as soy-based resins, and reinforced with crystalline high strength bacterial cellulose (BC) fibers. Bacterial cellulose is produced by providing a bacterial cellulose-producing bacterium such as Acetobacter xylinum providing an inexpensive bacteria nutritional medium culturing the bacterium in the bacteria nutritional medium under conditions to produce bacterial cellulose and isolating bacterial cellulose produced by cultured bacteria from the bacteria nutritional medium. The bacteria nutritional medium comprises an inexpensive carbon source that is a plant-based seed extract. The seed extract is derived from a plant-based seed comprising soluble sugars.

NETRAVALI ANIL N

162

BOGUS BACTERIA...  

Science.gov (United States)

Here are some websites to get you started... Just click on the links and start searching! microbe world- bacteria Bacteria Rule Quiz! Bacteria.... Harmful Bacteria Bacteria Museum Bacteria! Microbes- all sorts of info... When you are finished looking at the sites or when you have enough information concerning bacteria, ask Mrs. Deaton for some books that can give you even more DETAIL!!! *Don\\'t forget to keep track of your information on your I-CHARTS... ...

Deaton, Mrs.

2007-01-24

163

Sulfur diagenesis in Everglades peat and origin of pyrite in coal  

Energy Technology Data Exchange (ETDEWEB)

The pattern of sulfur transformation in peat across the Everglades basin indicates that pyrite formation in organic-rich swamps depends on the use of organic oxysulfur compounds in dissimilatory respiration by sulfur-reducing bacteria. This paragenesis explains the primary distribution of sulfur compounds in low-sulfur coals and possibly in most coals and many organic-rich soils and sediments. It also accounts for the occurrence of framboidal pyrite bound in fossil tissue in coal and sediments.

Altschuler, Z.S.; Schnepfe, M.M.; Silber, C.C.; Simon, F.O.

1983-07-15

164

Autotrophy of green non-sulphur bacteria in hot spring microbial mats: biological explanations for isotopically heavy organic carbon in the geological record.  

UK PubMed Central (United Kingdom)

Inferences about the evidence of life recorded in organic compounds within the Earth's ancient rocks have depended on 13C contents low enough to be characteristic of biological debris produced by the well-known CO2 fixation pathway, the Calvin cycle. 'Atypically' high values have been attributed to isotopic alteration of sedimentary organic carbon by thermal metamorphism. We examined the possibility that organic carbon characterized by a relatively high 13C content could have arisen biologically from recently discovered autotrophic pathways. We focused on the green non-sulphur bacterium Chloroflexus aurantiacus that uses the 3-hydroxypropionate pathway for inorganic carbon fixation and is geologically significant as it forms modern mat communities analogous to stromatolites. Organic matter in mats constructed by Chloroflexus spp. alone had relatively high 13C contents (-14.9%) and lipids diagnostic of Chloroflexus that were also isotopically heavy (-8.9% to -18.5%). Organic matter in mats constructed by Chloroflexus in conjunction with cyanobacteria had a more typical Calvin cycle signature (-23.5%). However, lipids diagnostic of Chloroflexus were isotopically enriched (-15.1% to -24.1%) relative to lipids typical of cyanobacteria (-33.9% to -36.3%). This suggests that, in mats formed by both cyanobacteria and Chloroflexus, autotrophy must have a greater effect on Chloroflexus carbon metabolism than the photoheterotrophic consumption of cyanobacterial photosynthate. Chloroflexus cell components were also selectively preserved. Hence, Chloroflexus autotrophy and selective preservation of its products constitute one purely biological mechanism by which isotopically heavy organic carbon could have been introduced into important Precambrian geological features.

van der Meer MT; Schouten S; de Leeuw JW; Ward DM

2000-08-01

165

Sulfuric acid poisoning  

Science.gov (United States)

Sulfuric acid is a very strong chemical that is corrosive. Corrosive means it can cause severe burns and ... or mucous membranes. This article discusses poisoning from sulfuric acid. This is for information only and not for ...

166

Microbial stabilization of sulfur-landen sorbents; Technical report, September 1--November 30, 1993  

Energy Technology Data Exchange (ETDEWEB)

Clean coal technologies that involve limestone for sulfur capture generate lime/limestone products laden with sulfur at various oxidation states. If sulfur is completely stabilized as sulfate, the spent sorbent is ready for commercial utilization as gypsum. However, the presence of reduced sulfur species requires additional processing. Thermal oxidation of reduced sulfur can result in undesirable release of SO{sub 2}. Microbial oxidation might provide an inexpensive and effective alternative. Sorbents laden with reduced forms of sulfur such as sulfide, sulfite, or various polythionate species serve as growth substrates for sulfur-oxidizing bacteria, which have the potential to convert all sulfur to sulfate. This quarter, efforts focused on determining the combined effects of dibasic acids (DBA) and Ca{sup +2} concentration on several strains of neutrophilic thiobacilli, including Thiobacillus neapolitanus ATCC 23639 and ATCC 23641, and an isolate, TQ1, which was obtained from a commercial sulfur dioxide scrubber that utilizes DBA.

Miller, K.W. [Illinois State Univ., Normal, IL (United States)

1993-12-31

167

Biochemistry of sulfur  

Energy Technology Data Exchange (ETDEWEB)

This book presents information on the following topics: the chemistry of sulfur; the oxidation states of sulfur; the reduction of sulfate and the oxidation of sulfide; the sulfur cycle; oxidation of inorganic sulfide; the metabolism and functions of methionine; taurine and the oxidative metabolism of cysteine; thiols, disulfides, and thioesters; thioethers; thiamine; biotin; sulfates; inherited disorders of sulfur metabolism; cystinuria; sulfur and the metabolism of xenobiotics; general aspects of xenobiotic metabolism; glutathione and sulfation of xenobiotics; and metabolic activation as a result of sulfate conjugation.

Huxtable, R.J.; LaFranconi, W.M.

1986-01-01

168

Sulfur tolerant anode materials  

Energy Technology Data Exchange (ETDEWEB)

The goal of this program is the development of a molten carbonate fuel cell (MCFC) anode which is more tolerant of sulfur contaminants in the fuel than the current state-of-the-art nickel-based anode structures. This program addresses two different but related aspects of the sulfur contamination problem. The primary aspect is concerned with the development of a sulfur tolerant electrocatalyst for the fuel oxidation reaction. A secondary issue is the development of a sulfur tolerant water-gas-shift reaction catalyst and an investigation of potential steam reforming catalysts which also have some sulfur tolerant capabilities. These two aspects are being addressed as two separate tasks.

1987-02-01

169

Sulfur-metabolizing bacterial populations in microbial mats of the Nakabusa hot spring, Japan.  

UK PubMed Central (United Kingdom)

At the Nakabusa hot spring, Japan, dense olive-green microbial mats develop in regions where the slightly alkaline, sulfidic effluent has cooled to 65°C. The microbial community of such mats was analyzed by focusing on the diversity, as well as the in situ distribution and function of bacteria involved in sulfur cycling. Analyses of 16S rRNA and functional genes (aprA, pufM) suggested the importance of three thermophilic bacterial groups: aerobic chemolithotrophic sulfide-oxidizing species of the genus Sulfurihydrogenibium (Aquificae), anaerobic sulfate-reducing species of the genera Thermodesulfobacterium/Thermodesulfatator, and filamentous anoxygenic photosynthetic species of the genus Chloroflexus. A new oligonucleotide probe specific for Sulfurihydrogenibium was designed and optimized for catalyzed reporter deposition fluorescence in situ hybridization (CARD-FISH). In situ hybridizations of thin mat sections showed a heterogeneous vertical distribution of Sulfurihydrogenibium and Chloroflexus. Sulfurihydrogenibium dominated near the mat surface (50% of the total mat biovolume), while Chloroflexus dominated in deeper layers (up to 64% of the total mat biovolume). Physiological experiments monitoring in vitro changes of sulfide concentration indicated slight sulfide production by sulfate-reducing bacteria under anoxic-dark conditions, sulfide consumption by photosynthetic bacteria under anoxic-light conditions and strong sulfide oxidation by chemolithotrophic members of Aquificae under oxic-dark condition. We therefore propose that Sulfurihydrogenibium spp. act as highly efficient scavengers of oxygen from the spring water, thus creating a favorable, anoxic environment for Chloroflexus and Thermodesulfobacterium/Thermodesulfatator in deeper layers.

Kubo K; Knittel K; Amann R; Fukui M; Matsuura K

2011-06-01

170

Bacteria Museum  

Science.gov (United States)

Who knew that bacteria had their own virtual museum? Here, visitors will "learn that not all bacteria are harmful, how they are used in industry, that they belong to the oldest living creatures on Earth", and many more interesting facts to discover about the diverse world of bacteria. The "Bacterial Species Files" tab at the top of the page, allows visitors to look up information on 40 different specific bacteria, from Anthrax to Yersinia enterocolitica. The information provided for each bacterium includes photographs, consumer guides, fact sheets, and scientific links. Visitors will find that the "Main Exhibits" tab addresses the basics about bacteria, as well as "Pathogenic Bacteria", "Evolution", "How We Fight Bacteria", and "Food and Water Safety". Visitors will surely enjoy the "Good Bacteria in Food" link found in the Food and Water Safety section, as it explains how some foods benefit from good bacteria, such as Swiss cheese, sausage, sauerkraut, chocolate, and coffee.

171

Sulfur rate control system  

Energy Technology Data Exchange (ETDEWEB)

A sulfur rate control system is described for substantially optimizing particulate removal performance of an electrostatic precipitator in fluid communication with a flue carrying combustion products of a fossil fuel, comprising: an electrostatic precipitator having an inlet for receiving a flue gas: means for injecting sulfur trioxide into a flue for mixing with said flue gas at a location preceding entry of said flue gas into said electrostatic precipitator, said injection of sulfur trioxide being varied responsive to a proportional control signal; and, control means coupled to both said flue and said sulfur trioxide injection means for generating said proportional control signal, said control means including (1) means for measuring a sulfur dioxide concentration quantity in said flue gas at a location preceding said sulfur trioxide injection means, (2) means for measuring a flow rate of particulates in said flue gas at a location preceding said sulfur trioxide injection means, and (3) a controller for calculating a ratio between said sulfur dioxide concentration quantity and said flow rate of particulates, said ratio calculating controller having a first input coupled to said sulfur dioxide measuring means and a second input coupled to said particulate flow rate measuring means for generating said proportional control signal in proportion to a difference between a predetermined value and said ratio between said sulfur dioxide concentration quantity and said flow rate of particulates, said ratio controller having an output coupled to said sulfur trioxide injection means for maximizing particulate removal efficiency of said electrostatic precipitator.

Bell, T.A.; Mullendore, M.G.; Kleinfeldt, T.E.; Walker, H.G. Jr.

1993-07-20

172

Sulfur in achondritic meteorites.  

Science.gov (United States)

Total sulfur abundances have been measured for 48 achondrites. For twenty eucrites they ranged from 370 to 3700 micrograms S/g with a median sulfur content of 1180 micrograms S/g. Sulfur abundances for howardites ranged from 1490 to 3240 micrograms S /g and had a median sulfur concentration of 2340 micrograms S/g. Diogenites' sulfur abundances ranged from 130 to 3170 micrograms S/g, with a median value of 1280 micrograms S/g. Four shergottites had a median sulfur content of 1940 micrograms S/g and ranged from 740 to 2540 micrograms S/g. Enstatite achondrites contained the greatest sulfur abundances of any achondrite group. They ranged from 2450 to 8580 micrograms S/g and had a median sulfur content of 6020 micrograms S/g and had a median sulfur content of 6020 micrograms S/g. A single Chassignite had a sulfur concentration of 360 micrograms S/g. The wide variations in sulfur concentrations for the achondrites reflect the small scale heterogeneous nature of these unique extraterrestrial materials due in large part to discrete sulfide mineral grains. PMID:11539026

Gibson, E K; Moore, C B; Primus, T M; Lewis, C F

1985-09-30

173

Sulfur in achondritic meteorites.  

UK PubMed Central (United Kingdom)

Total sulfur abundances have been measured for 48 achondrites. For twenty eucrites they ranged from 370 to 3700 micrograms S/g with a median sulfur content of 1180 micrograms S/g. Sulfur abundances for howardites ranged from 1490 to 3240 micrograms S /g and had a median sulfur concentration of 2340 micrograms S/g. Diogenites' sulfur abundances ranged from 130 to 3170 micrograms S/g, with a median value of 1280 micrograms S/g. Four shergottites had a median sulfur content of 1940 micrograms S/g and ranged from 740 to 2540 micrograms S/g. Enstatite achondrites contained the greatest sulfur abundances of any achondrite group. They ranged from 2450 to 8580 micrograms S/g and had a median sulfur content of 6020 micrograms S/g and had a median sulfur content of 6020 micrograms S/g. A single Chassignite had a sulfur concentration of 360 micrograms S/g. The wide variations in sulfur concentrations for the achondrites reflect the small scale heterogeneous nature of these unique extraterrestrial materials due in large part to discrete sulfide mineral grains.

Gibson EK; Moore CB; Primus TM; Lewis CF

1985-09-01

174

Green Chemistry  

Science.gov (United States)

This special feature page from the American Chemical Society (ACS) showcases the up-and-coming field of "green chemistry," that is, the development of chemical products and processes that eliminate or reduce the use and generation of hazardous substances. A list of principles behind green chemistry, a searchable bibliography of green chemistry references, green chemistry links (including conferences), and an online preview of the ACS-published book Real-World Cases in Green Chemistry are all found at the site. Five video clips on green chemistry from the standpoint of academia, industry, and small business are also featured (Windows Media Player). This page comes from ACS's Green Chemistry Project, a three-year educational project to develop and disseminate green chemistry educational materials for graduate and undergraduate chemistry students. Check back often for updates.

2002-01-01

175

Methanotrophic bacteria.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Methane-utilizing bacteria (methanotrophs) are a diverse group of gram-negative bacteria that are related to other members of the Proteobacteria. These bacteria are classified into three groups based on the pathways used for assimilation of formaldehyde, the major source of cell carbon, and other ph...

Hanson, R S; Hanson, T E

176

Green, green, green...; Gruen, gruen, gruen...  

Energy Technology Data Exchange (ETDEWEB)

Green are the dreams of the photovoltaics industry. The new concept of Triple Green involves three aspects: clean power generation, recycling of modules, and environment-friendly manufacturing of modules. This is still a vision for the future as eco-factories will require high investments to start with. (orig.)

Rentzing, Sascha; Heup, Juergen

2010-03-15

177

New targets and inhibitors of mycobacterial sulfur metabolism.  

UK PubMed Central (United Kingdom)

The identification of new antibacterial targets is urgently needed to address multidrug resistant and latent tuberculosis infection. Sulfur metabolic pathways are essential for survival and the expression of virulence in many pathogenic bacteria, including Mycobacterium tuberculosis. In addition, microbial sulfur metabolic pathways are largely absent in humans and therefore, represent unique targets for therapeutic intervention. In this review, we summarize our current understanding of the enzymes associated with the production of sulfated and reduced sulfur-containing metabolites in Mycobacteria. Small molecule inhibitors of these catalysts represent valuable chemical tools that can be used to investigate the role of sulfur metabolism throughout the Mycobacterial lifecycle and may also represent new leads for drug development. In this light, we also summarize recent progress made in the development of inhibitors of sulfur metabolism enzymes.

Paritala H; Carroll KS

2013-04-01

178

Apparatus for recovery of sulfur  

Energy Technology Data Exchange (ETDEWEB)

This patent describes an apparatus for the recovery of sulfur from an underground sulfur formation. It comprises means for the injection of hot water into contact with the underground sulfur formation; means to permit the water and elemental sulfur to remain in contact, so as to melt at least a portion of the sulfur and form a mixture of molten sulfur and water; means for removing the mixture of molten sulfur and heated water to the surface; means for separating the water and sulfur mixture to recover molten sulfur and water; and means to recycle the water to the underground formation.

Peters, J.R.; Ramey, M.E.; Seyffert, A.E.; Canon, J.L.; Robinson, M.W.; Abercrombie, W.T.

1989-09-26

179

DSRP, Direct Sulfur Production  

Energy Technology Data Exchange (ETDEWEB)

Hot-gas desulfurization processes for IGCC and other advanced power applications utilize regenerable mixed-metal oxide sorbents to remove hydrogen sulfide (H{sub 2}S) from raw coal gas. Regeneration of these sorbents produces an off-gas typically containing I to 3 percent sulfur dioxide (SO{sub 2}). Production of elemental sulfur is a highly desirable option for the ultimate disposal of the SO{sub 2} content of this off-gas. Elemental sulfur, an essential industrial commodity, is easily stored and transported. As shown in Figure 1, the DSRP consists of two catalytic reactors, each followed by a sulfur condenser. Hot regenerator off-gas is mixed with a hot coal-gas slip stream and fed to the first DSRP reactor. Approximately 95 percent of the sulfur gas in the inlet stream of the first reactor is converted to elemental sulfur. The outlet gas of the first DSRP reactor is cooled, condensing out sulfur. The gas could be recycled after the Stage I condenser. Alteratively, by adjusting the proportion of coal gas to regenerator off-gas, the effluent composition of the first reactor can be controlled to produce an H{sub 2}S-to-SO{sub 2} ratio of 2 to 1 at 95 percent sulfur conversion. The cooled gas stream is then passed to the second DSRP reactor where 80 to 90 percent of the remaining sulfur compounds are converted to elemental sulfur via the modified Claus reaction at high pressure. The total efficiency of the two reactors for the conversion of sulfur compounds to elemental sulfur is projected to be about 99.5 percent.

Gangwal, S.K.; McMichael, W.J.; Agarwal, S.K.; Jang, B.L.; Howe, G.B. [Research Triangle Inst., Research Triangle Park, NC (United States); Chen, D.H.; Hopper, J.R. [Lamar Univ., Beaumont, TX (United States)

1993-08-01

180

Sulfur polymer cement concrete  

International Nuclear Information System (INIS)

[en] Sulfur-based composite materials formulated using sulfur polymer cement (SPC) and mineral aggregates are described and compared with conventional portland cement based materials. Materials characteristics presented include mechanical strength, chemical resistance, impact resistance, moisture permeation, and linear shrinkage during placement and curing. Examples of preparation and placement of sulfur polymer cement concrete (SC) are described using commercial scale equipment. SC applications presented are focused into hostile chemical environments where severe portland cement concrete (PCC) failure has occurred

1990-01-01

 
 
 
 
181

A new role for sulfur in arsenic cycling.  

Science.gov (United States)

Sulfur and arsenic often coexist in the environment and share similar microbial redox transformations. We examined the effects of sulfide on aerobic arsenite oxidation in alkaline lake water samples and in laboratory enrichment cultures. Significant arsenite oxidation occurred only in treatments with bacteria present, and production of arsenate was greatly enhanced by the addition of sulfide or thiosulfate. IC-ICP-MS analysis of samples showed that mono- and dithioarsenate formed in arsenite + sulfide amended lake water. Our data indicate that these two thioarsenic compounds are fairly stable in sterile alkaline solutions, but are transformed predominantly to arsenate when bacteria are present. Enrichment culture experiments suggest that sulfur-oxidizing bacteria use free or arsenic-bound sulfur as a growth substrate and directly or indirectly transform arsenite and thioarsenates to arsenate during growth. Increases in cell density resulted in more rapid conversion of arsenite and thioarsenates. The rate and extent of these processes appearto be controlled bythe concentration of bacteria and the ratio of reduced sulfur to arsenite present. Sulfur-driven arsenite oxidation and microbial thioarsenate transformation may be important biogeochemical processes in the arsenic cycle of our study site (Mono Lake, CA, USA) and other alkaline environments as well. PMID:18350879

Fisher, Jenny C; Wallschläger, Dirk; Planer-Friedrich, Britta; Hollibaugh, James T

2008-01-01

182

Photosynthetic reaction centers in bacteria  

Energy Technology Data Exchange (ETDEWEB)

The photochemistry of photosynthesis begins in complexes called reaction centers. These have become model systems to study the fundamental process by which plants and bacteria convert and store solar energy as chemical free energy. In green plants, photosynthesis occurs in two systems, each of which contains a different reaction center, working in series. In one, known as photosystem 1, oxidized nicotinamide adenine dinucleotide phosphate (NADP[sup +]) is reduced to NADPH for use in a series of dark reactions called the Calvin cycle, named for Nobel Laureate Melvin Calvin, by which carbon dioxide is converted into useful fuels such as carbohydrates and sugars. In the other half of the photosynthetic machinery of green plants, called photosystem 2, water is oxidized to produce molecular oxygen. A different form of photosynthesis occurs in photosynthetic bacteria, which typically live at the bottom of ponds and feed on organic debris. Two main types of photosynthetic bacteria exist: purple and green. Neither type liberates oxygen from water. Instead, the bacteria feed on organic media or inorganic materials, such as sulfides, which are easier to reduce or oxidize than carbon dioxide or water. Perhaps in consequence, their photosynthetic machinery is simpler than that of green, oxygen-evolving plants and their primary photochemistry is better understood.

Norris, J.R. (Argonne National Lab., IL (United States) Univ. of Chicago, IL (United States)); Schiffer, M. (Argonne National Lab., IL (United States))

1990-07-30

183

X-Ray Absorption Spectroscopy As a Probe of Microbial Sulfur Biochemistry: the Nature of Bacterial Sulfur Globules Revisited  

Energy Technology Data Exchange (ETDEWEB)

The chemical nature of the sulfur in bacterial sulfur globules has been the subject of controversy for a number of years. Sulfur K-edge X-ray absorption spectroscopy (XAS) is a powerful technique for probing the chemical forms of sulfur in situ, but two groups have used it with very different conclusions. The root of the controversy lies with the different detection strategies used by the two groups, which result in very different spectra. This paper seeks to resolve the controversy. We experimentally demonstrate that the use of transmittance detection for sulfur K-edge XAS measurements is highly prone to spectroscopic distortions and that much of the published work on sulfur bacteria is very likely based on distorted data. We also demonstrate that all three detection methods used for X-ray absorption experiments yield essentially identical spectra when the measurements are carried out under conditions where no experimental distortions are expected. Finally, we turn to the original question--the chemical nature of bacterial sulfur. We examine isolated sulfur globules of Allochromatium vinosum and intact cells of a strain of magnetotactic coccus and show that XAS indicates the presence of a chemical form of sulfur resembling S{sub 8}.

George, G.N.; Gnida, M.; Bazylinski, D.A.; Prince, R.C.; Pickering, I.J.

2009-05-18

184

Sulfur compounds in petroleum  

Energy Technology Data Exchange (ETDEWEB)

Part 1 of the paper examines theories as to the origin of sulfur compounds in petroleum, the influence of these compounds on the uses and processing of petroleum, and the composition of the sulfur-containing component of petroleum. Part 2 describes methods of separating sulfur compounds from petroleum: physical -- distillation, liquid chromatography, gas chromatography, thermodiffusion -- and chemical -- extraction of thiols and sulfides, use of addition reactions. Methods are proposed for identifying sulfur compounds in petroleum: group analysis, and even trace analysis by gas chromatography, catalytic desulfurization, and spectrometry, especially mass spectrometry.

Kuras, M.

1980-01-01

185

Microbial sulfur metabolism  

Energy Technology Data Exchange (ETDEWEB)

In nature, sulfur occurs in many different oxidation states and is one of the most versatile elements in life. It is an integral part of many important cell constituents, such as the amino acids cysteine and methionine, and many sulfur compounds serve as the basis for energy-related processes in prokaryotes. In recent years, new methods have been applied to study the biochemistry and molecular biology of reactions of the global sulfur cycle, the microorganisms involved and their physiology, metabolism and ecology. These activities have uncovered fascinating new insights for the understanding of aerobic and anaerobic sulfur metabolism. (orig.)

Dahl, Christiane [Bonn Univ. (Germany). Inst. for Microbiology and Biotechnology; Friedrich, Cornelius G. (eds.) [Dortmund Univ. (Germany). Dept. of Biochemical and Chemical Engineering

2008-07-01

186

ADVANCED SULFUR CONTROL CONCEPTS  

Energy Technology Data Exchange (ETDEWEB)

Conventional sulfur removal in integrated gasification combined cycle (IGCC) power plants involves numerous steps: COS (carbonyl sulfide) hydrolysis, amine scrubbing/regeneration, Claus process, and tail-gas treatment. Advanced sulfur removal in IGCC systems involves typically the use of zinc oxide-based sorbents. The sulfides sorbent is regenerated using dilute air to produce a dilute SO{sub 2} (sulfur dioxide) tail gas. Under previous contracts the highly effective first generation Direct Sulfur Recovery Process (DSRP) for catalytic reduction of this SO{sub 2} tail gas to elemental sulfur was developed. This process is currently undergoing field-testing. In this project, advanced concepts were evaluated to reduce the number of unit operations in sulfur removal and recovery. Substantial effort was directed towards developing sorbents that could be directly regenerated to elemental sulfur in an Advanced Hot Gas Process (AHGP). Development of this process has been described in detail in Appendices A-F. RTI began the development of the Single-step Sulfur Recovery Process (SSRP) to eliminate the use of sorbents and multiple reactors in sulfur removal and recovery. This process showed promising preliminary results and thus further process development of AHGP was abandoned in favor of SSRP. The SSRP is a direct Claus process that consists of injecting SO{sub 2} directly into the quenched coal gas from a coal gasifier, and reacting the H{sub 2}S-SO{sub 2} mixture over a selective catalyst to both remove and recover sulfur in a single step. The process is conducted at gasifier pressure and 125 to 160 C. The proposed commercial embodiment of the SSRP involves a liquid phase of molten sulfur with dispersed catalyst in a slurry bubble-column reactor (SBCR).

Apostolos A. Nikolopoulos; Santosh K. Gangwal; William J. McMichael; Jeffrey W. Portzer

2003-01-01

187

Future Sulfur Dioxide Emissions  

Energy Technology Data Exchange (ETDEWEB)

The importance of sulfur dioxide emissions for climate change is now established, although substantial uncertainties remain. This paper presents projections for future sulfur dioxide emissions using the MiniCAM integrated assessment model. A new income-based parameterization for future sulfur dioxide emissions controls is developed based on purchasing power parity (PPP) income estimates and historical trends related to the implementation of sulfur emissions limitations. This parameterization is then used to produce sulfur dioxide emissions trajectories for the set of scenarios developed for the Special Report on Emission Scenarios (SRES). We use the SRES methodology to produce harmonized SRES scenarios using the latest version of the MiniCAM model. The implications, and requirements, for IA modeling of sulfur dioxide emissions are discussed. We find that sulfur emissions eventually decline over the next century under a wide set of assumptions. These emission reductions result from a combination of emission controls, the adoption of advanced electric technologies, and a shift away from the direct end use of coal with increasing income levels. Only under a scenario where incomes in developing regions increase slowly do global emission levels remain at close to present levels over the next century. Under a climate policy that limits emissions of carbon dioxide, sulfur dioxide emissions fall in a relatively narrow range. In all cases, the relative climatic effect of sulfur dioxide emissions decreases dramatically to a point where sulfur dioxide is only a minor component of climate forcing by the end of the century. Ecological effects of sulfur dioxide, however, could be significant in some developing regions for many decades to come.

Smith, Steven J.; Pitcher, Hugh M.; Wigley, Tom M.

2005-12-01

188

Advanced sulfur control concepts  

Energy Technology Data Exchange (ETDEWEB)

Regenerable metal oxide sorbents, such as zinc titanate, are being developed to efficiently remove hydrogen sulfide (H{sub 2}S) from coal gas in advanced power systems. Dilute air regeneration of the sorbents produces a tailgas containing a few percent sulfur dioxide (SO{sub 2}). Catalytic reduction of the SO{sub 2} to elemental sulfur with a coal gas slipstream using the Direct Sulfur Recovery Process (DSRP) is a leading first-generation technology. Currently the DSRP is undergoing field testing at gasifier sites. The objective of this study is to develop second-generation processes that produce elemental sulfur without coal gas or with limited use. Novel approaches that were evaluated to produce elemental sulfur from sulfided sorbents include (1) sulfur dioxide (SO{sub 2}) regeneration, (2) substoichiometric (partial) oxidation, (3) steam regeneration followed by H{sub 2}S oxidation, and (4) steam-air regeneration. Preliminary assessment of these approaches indicated that developing SO{sub 2} regeneration faced the fewest technical and economic problems among the four process options. Elemental sulfur is the only likely product of SO{sub 2} regeneration and the SO{sub 2} required for the regeneration can be obtained by burning a portion of the sulfur produced. Experimental efforts have thus been concentrated on SO{sub 2}-based regeneration processes. Results from laboratory investigations are presented and discussed.

Gangwal, S.K.; Turk, B.S.; Gupta, R.P.

1995-11-01

189

GEOCHEMISTRY OF SULFUR IN IRON CORROSION SCALES FOUND IN DRINKING WATER DISTRIBUTION SYSTEMS  

Science.gov (United States)

Iron-sulfur geochemistry is important in many natural and engineered environments, including drinking water systems. In the anaerobic environment beneath scales of corroding iron drinking water distribution system pipes, sulfate reducing bacteria (SRB) produce sulfide from natu...

190

Building Green  

Science.gov (United States)

There's a great deal of talk about "building green" in the architecture and design world, but to many, this phrase may not mean a great deal. This website, created by the Building Green company, can help the uninitiated learn more about this subject. First-time visitors should click on the "Green Building Information" area. Here they can get answers to such question as "What is green?" and also learn more about green design strategies and the LEED rating system. Right next to this section is the "Case Studies" area, which features green building projects like elementary schools, commercial facilities, and university buildings. The site is rounded out by a "News" area and a detailed bibliography of websites, print resources, and so on.

191

Pulsation combustion of sulfur  

Energy Technology Data Exchange (ETDEWEB)

The present trend in sulfuric acid manufacture is to use elemental sulfur as the basic raw material. In this context, refinement of the sulfur burning process in chamber furnaces, which would enhance the efficiency of the sulfuric acid lines, has been acquiring special importance. One avenue of refinement of the combustion technology is to execute the process in the pulsation mode, which is achieved by intermittent supply of the fuel or the oxidant into the combustion zone. The process can be executed by the traditional means from the drop surface (diffusional combustion) and by ejection of vapors from the drop interior (explosive combustion). The process can be identified from the breakdown of the shell of the combustion products around the burning drop. The authors of this paper investigated combustion of calibrated sulfur drops with pulsating supply of blasting air in a laboratory setup that simulates a chamber furnace.

Klepach, A.S.; Shelyakin, A.P.; Vasil' ev, B.T.

1987-08-20

192

Elemental sulfur recovery process  

Energy Technology Data Exchange (ETDEWEB)

An improved catalytic reduction process for the direct recovery of elemental sulfur from various SO.sub.2 -containing industrial gas streams. The catalytic process provides combined high activity and selectivity for the reduction of SO.sub.2 to elemental sulfur product with carbon monoxide or other reducing gases. The reaction of sulfur dioxide and reducing gas takes place over certain catalyst formulations based on cerium oxide. The process is a single-stage, catalytic sulfur recovery process in conjunction with regenerators, such as those used in dry, regenerative flue gas desulfurization or other processes, involving direct reduction of the SO.sub.2 in the regenerator off gas stream to elemental sulfur in the presence of a catalyst.

Flytzani-Stephanopoulos, Maria (Winchester, MA); Hu, Zhicheng (Somerville, MA)

1993-01-01

193

Nanostructured sulfur cathodes.  

UK PubMed Central (United Kingdom)

Rechargeable Li/S batteries have attracted significant attention lately due to their high specific energy and low cost. They are promising candidates for applications, including portable electronics, electric vehicles and grid-level energy storage. However, poor cycle life and low power capability are major technical obstacles. Various nanostructured sulfur cathodes have been developed to address these issues, as they provide greater resistance to pulverization, faster reaction kinetics and better trapping of soluble polysulfides. In this review, recent developments on nanostructured sulfur cathodes and mechanisms behind their operation are presented and discussed. Moreover, progress on novel characterization of sulfur cathodes is also summarized, as it has deepened the understanding of sulfur cathodes and will guide further rational design of sulfur electrodes.

Yang Y; Zheng G; Cui Y

2013-04-01

194

Green Chemistry  

Energy Technology Data Exchange (ETDEWEB)

Green chemistry is the science of chemistry used in a way that will not use or create hazardous substances. Dr. Rui Resendes is working in this field at GreenCentre Canada, an offshoot of PARTEQ Innovations in Kingston, Ontario. GreenCentre's preliminary findings suggest their licensed product {sup S}witchable Solutions{sup ,} featuring 3 classes of solvents and a surfactant, may be useful in bitumen oil sands extraction.

Collison, Melanie

2011-05-15

195

Autotrophic denitrification of high-salinity wastewater using elemental sulfur: Batch tests  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The feasibility of autotrophic denitrification of a high-salinity wastewater using sulfur-oxidizing autotrophic denitrificants was studied. These autotrophic bacteria oxidize elemental sulfur to sulfate while reducing nitrate to elemental nitrogen gas, thereby eliminating the need for the addition o...

Koenig, A; Liu, L

196

(Application of selected microorganisms for organic sulfur removal from coal). [Thiobacillus thiooxidans  

Energy Technology Data Exchange (ETDEWEB)

Research continues on methods using microorganisms to desulfurize coal. Topics reported on include: coal procurement and preparation, analytical procedures for characterization of total organic sulfur, organic sulfur removal, screening for 4S+ bacteria, extraction of liquid medium, and bacterial growth with depyritized coal. (VC)

Boyden, B.H.

1989-06-15

197

Geochemical, biogeochemical, and sedimentological studies of the Green River Formation. Wyoming, Utah, and Colorado  

Energy Technology Data Exchange (ETDEWEB)

The report contains the following sections: Introduction; Sulfur geochemistry and isotopy of the Green River Formation, Wyoming, Utah, and Colorado; A preliminary study of the carbon and nitrogen isotopic biogeochemistry of lacustrine sedimentary rocks from the Green River Formation, Wyoming, Utah, and Colorado; Trace elements in pyrites of the Green River Formation oil shales, Wyoming, Utah, and Colorado; An experimental study of goethite sulfidization--Relationships to the diagenesis of iron and sulfur; Effects of source, depositional environment, and diagenesis on characteristics of organic matter in oil shale from the Green River Formation, Wyoming, Utah, and Colorado; Petrography of iron sulfide minerals in the Green River Formation of Wyoming, Utah, and Colorado.

Tuttle, M.L.

1991-01-01

198

Green building  

UK PubMed Central (United Kingdom)

A green building (1) is disclosed. The green building (1) includes at least one plant growing area (10) with plants, at least one lighting device (15) and a heat pump (14). The lighting device (15) radiates light onto the plant growing area (10). The heat pump (14) receives environmental heat.

TSAI WEN-KUEI

199

GREEN BUILDING  

UK PubMed Central (United Kingdom)

A green building is disclosed. The green building includes at least one plant growing area with plants, at least one lighting device and a heat pump. The lighting device radiates light onto the plant growing area. The heat pump receives environmental heat.

TSAI WEN-KUEI

200

Green thermodynamics  

Energy Technology Data Exchange (ETDEWEB)

Green components of thermodynamics were identified and general aspects of green practices associated with thermodynamics were assessed. Energy uses associated with fossil fuels were reviewed. Green energy sources such as solar, wind, geothermal and hydropower were discussed, as well as biomass plantations. Ethanol production practices were reviewed. Conservation practices in the United States were outlined. Energy efficiency and exergy analyses were discussed. Energy intensity measurements and insulation products for houses were also reviewed. Five case studies were presented to illustrate aspects of green thermodynamics: (1) light in a classroom; (2) fuel saved by low-resistance tires; and (3) savings with high-efficiency motors; (4) renewable energy; and (5) replacing a valve with a turbine at a cryogenic manufacturing facility. It was concluded that the main principles of green thermodynamics are to ensure that all material and energy inputs minimize the depletion of energy resources; prevent waste; and improve or innovate technologies that achieve sustainability. 17 refs., 2 tabs., 9 figs.

Cengel, Y.A. [Nevada Univ., Reno, NV (United States). Dept. of Mechanical Engineering

2006-07-01

 
 
 
 
201

Genetic transfer in acidophilic bacteria  

Energy Technology Data Exchange (ETDEWEB)

There is increasing interest in the use of microorganisms to recover metals from ores, as well as to remove sulfur from coal. These so-called bioleaching processes are mediated by a number of bacteria. The best-studied of these organisms are acidophiles including Thiobacillus and Acidiphilium species. Our laboratory has focused on developing genetic strategies to allow the manipulation of acidophilic bacteria to improve and augment their utility in large scale operations. We have recently been successful in employing conjugation for interbacterial transfer of genetic information, as well as in directly transforming Acidiphilium by use of electroporation. We are now testing the properties of IncPl, IncW and IncQ plasmid vectors in Acidiphilium to determine their relative usefulness in routine manipulation of acidophiles and transfer between organisms. This study also allows us to determine the natural ability of these bacteria to transfer genetic material amongst themselves in their particular environment. 21 refs., 3 figs., 2 tabs.

Roberto, F.F.; Glenn, A.W.; Bulmer, D.; Ward, T.E.

1990-01-01

202

Marine Bacteria from Danish Coastal Waters Show Antifouling Activity against the Marine Fouling Bacterium Pseudoalteromonas sp. Strain S91 and Zoospores of the Green Alga Ulva australis Independent of Bacteriocidal Activity?†  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The aims of this study were to determine if marine bacteria from Danish coastal waters produce antifouling compounds and if antifouling bacteria could be ascribed to specific niches or seasons. We further assess if antibacterial effect is a good proxy for antifouling activity. We isolated 110 bacter...

Bernbom, Nete; Ng, Yoke Yin; Kjelleberg, Staffan; Harder, Tilmann; Gram, Lone

203

The Microworld of Marine-Bacteria  

DEFF Research Database (Denmark)

Microsensor studies show that the marine environment in the size scale of bacteria is physically and chemically very different from the macroenvironment. The microbial world of the sediment-water interface is thus dominated by water viscosity and steep diffusion gradients. Because of the diverse metabolism types, bacteria in the mostly anoxic sea floor play an important role in the major element cycles of the ocean. The communities of giant, filamentous sulfur bacteria that live in the deep-sea hydrothermal vents or along the Pacific coast of South America are presented here as examples.

JØRGENSEN, BB

1995-01-01

204

Sulfur removal from gases and sulfur recovery  

Energy Technology Data Exchange (ETDEWEB)

LINDE offers methods and technical know-how over the complete range of gas desulfurization and sulfur recovery, with some of the methods available being based on conventional techniques, and others on completely novel developments. The latter include processes allowing removal of sulfur contents from some ppm in the feed gas up to practically 90 p.c. of H2S. Two processes are to be pointed out, namely the SULFOLIN process and the SOLINOX process. Some other processes of importance have been developed for purification of Claus off-gas. Latest developments have led to a quasi isothermal Claus process offering improvements over the conventional methods in terms of simplicity and efficiency.

Heisel, M.; Linde, G.; Marold, F.; Weber, G.

1984-12-01

205

Sulfur in fuel tester  

UK PubMed Central (United Kingdom)

A portable diesel fuel tester and a method of its use are provided. A sample of diesel fuel is placed in a sample tray of the tester. The diesel fuel is heated to a gas state and circulated to a SO2 sensor by an air pump. The SO2 sensor determines the level of sulfur in the diesel fuel based on the SO2 levels. The sulfur level is displayed on an LCD screen for viewing by the user.

KINKADE JR. CHARLES E

206

Sulfur extraction method  

Energy Technology Data Exchange (ETDEWEB)

Circulating oil used for removal of sulfur in sour gas wells is contacted with an aqueous solution of a lower polysulfide of an alkali metal or ammonia to form a higher polysulfide of the alkali metal or ammonia, and the oil is separated from the higher polysulfide. The higher polysulfide is converted to lower polysulfide by precipitating part of the sulfur contained therein , and the lower polysulfide is recycled for oil desulfurization.

Blytas, G.C.

1980-10-28

207

Green Nail Syndrome  

Science.gov (United States)

... Favorite Name: Category: Share: Yes No, Keep Private Green Nail Syndrome Share | Green nail syndrome (GNS) is an infection of the ... discoloration of nails, also known as chloronychia. The green discoloration varies from blue-green to dark green ...

208

Genome-Wide Transcriptional Profiling of the Purple Sulfur Bacterium Allochromatium vinosum DSM 180T during Growth on Different Reduced Sulfur Compounds.  

UK PubMed Central (United Kingdom)

The purple sulfur bacterium Allochromatium vinosum DSM 180(T) is one of the best-studied sulfur-oxidizing anoxygenic phototrophic bacteria, and it has been developed into a model organism for laboratory-based studies of oxidative sulfur metabolism. Here, we took advantage of the organism's high metabolic versatility and performed whole-genome transcriptional profiling to investigate the response of A. vinosum cells upon exposure to sulfide, thiosulfate, elemental sulfur, or sulfite compared to photoorganoheterotrophic growth on malate. Differential expression of 1,178 genes was observed, corresponding to 30% of the A. vinosum genome. Relative transcription of 551 genes increased significantly during growth on one of the different sulfur sources, while the relative transcript abundance of 627 genes decreased. A significant number of genes that revealed strongly enhanced relative transcription levels have documented sulfur metabolism-related functions. Among these are the dsr genes, including dsrAB for dissimilatory sulfite reductase, and the sgp genes for the proteins of the sulfur globule envelope, thus confirming former results. In addition, we identified new genes encoding proteins with appropriate subcellular localization and properties to participate in oxidative dissimilatory sulfur metabolism. Those four genes for hypothetical proteins that exhibited the strongest increases of mRNA levels on sulfide and elemental sulfur, respectively, were chosen for inactivation and phenotypic analyses of the respective mutant strains. This approach verified the importance of the encoded proteins for sulfur globule formation during the oxidation of sulfide and thiosulfate and thereby also documented the suitability of comparative transcriptomics for the identification of new sulfur-related genes in anoxygenic phototrophic sulfur bacteria.

Weissgerber T; Dobler N; Polen T; Latus J; Stockdreher Y; Dahl C

2013-09-01

209

Green tea  

Science.gov (United States)

... your health provider.Medications used to treat cancer (Boronic acid-based proteasome inhibitors)Green tea might interact with some medications used to treat cancer (boronic acid-based proteasome inhibitors). This might decrease its effectiveness ...

210

Decon Green.  

Science.gov (United States)

Simple solutions of hydrogen peroxide, carbonate/bicarbonate, and co- solvents afford the rapid, broad-spectrum decontamination of chemical warfare agents. Such formulations, termed 'DECON GREEN', are non-toxic, non-corrosive and environmentally friendly....

G. W. Wagner P. W. Bartram L. R. Procell V. D. Henderson Y. Yang

2002-01-01

211

Greening platform  

UK PubMed Central (United Kingdom)

Disclosed is a greening platform which is characterized in that an urban plain greening land is prepared into parking space, a plurality of upright posts is arranged on the ground of the parking space, the upper ends of the upright posts are built into a platform by cement slabs, a plurality of cement grooves are poured on the platform, soils are accumulated in the grooves for planting flowers, plants, shrubs and the like, and an auxiliary frame is arranged around the platform to provide a growing space for climbing plants. One end of the platform is equipped with a stair for people to step on the platform to play and relax. The greening platform not only guarantees efficient greening areas, but also adds the parking space, thereby alleviating parking problems in urban areas.

JIJUN CHEN

212

--- but bacteria fuel the debate  

Energy Technology Data Exchange (ETDEWEB)

Bacteria that convert carbon dioxide in the air into energy could be used as an alternative source of fuel with no conflict with food production. Chlorella, a green alga has a fast growth rate and it is estimated that each hectare of growth area could produce the equivalent of 50,000 barrels of crude oil a year. Arthrobactir AK19 can accumulate over 85% of its body weight as fat which can then be refined and burnt.

1981-01-15

213

Aircraft exhaust sulfur emissions  

Energy Technology Data Exchange (ETDEWEB)

The extent to which fuel sulfur is converted to SO{sub 3} during combustion and the subsequent turbine flow in supersonic and subsonic aircraft engines is estimated numerically. The analysis is based on: a flamelet model with non-equilibrium sulfur chemistry for the combustor, and a one-dimensional, two-stream model with finite rate chemical kinetics for the turbine. The results indicate that between 2% and 10% of the fuel sulfur is emitted as SO{sub 3}. It is also shown that, for a high fuel sulfur mass loading, conversion in the turbine is limited by the level of atomic oxygen at the combustor exit, leading to higher SO{sub 2} oxidation efficiency at lower fuel sulfur loadings. While SO{sub 2} and SO{sub 3} are the primary oxidation products, the model results further indicate H{sub 2}SO{sub 4} levels on the order of 0.1 ppm for supersonic expansions through a divergent nozzle. This source of fully oxidized S(6) (SO{sub 3} + H{sub 2}SO{sub 4}) exceeds previously calculated S(6) levels due to oxidation of SO{sub 2} by OH in the exhaust plume outside the engine nozzle. (author) 26 refs.

Brown, R.C.; Anderson, M.R.; Miake-Lye, R.C.; Kolb, C.E. [Aerodyne Research, Inc., Billerica, MA (United States). Center for Chemical and Environmental Physics; Sorokin, A.A.; Buriko, Y.I. [Scientific Research Center `Ecolen`, Moscow (Russian Federation)

1997-12-31

214

Sodium sulfur battery seal  

Energy Technology Data Exchange (ETDEWEB)

This disclosure is directed to an improvement in a sodium sulfur battery construction in which a seal between various battery compartments is made by a structure in which a soft metal seal member is held in a sealing position by holding structure. A pressure applying structure is used to apply pressure on the soft metal seal member when it is being held in sealing relationship to a surface of a container member of the sodium sulfur battery by the holding structure. The improvement comprises including a thin, well-adhered, soft metal layer on the surface of the container member of the sodium sulfur battery to which the soft metal seal member is to be bonded.

Mikkor, Mati (Ann Arbor, MI)

1981-01-01

215

Catalyst for the reduction of sulfur dioxide to elemental sulfur  

Energy Technology Data Exchange (ETDEWEB)

The inventive catalysts allow for the reduction of sulfur dioxide to elemental sulfur in smokestack scrubber environments. The catalysts have a very high sulfur yield of over 90% and space velocity of 10,000 h.sup.-1. They also have the capacity to convert waste gases generated during the initial conversion into elemental sulfur. The catalysts have inexpensive components, and are inexpensive to produce. The net impact of the invention is to make this technology practically available to industrial applications.

Jin, Yun (Peking, CN); Yu, Qiquan (Peking, CN); Chang, Shih-Ger (El Cerrito, CA)

1996-01-01

216

Phosphorothioate DNA as an antioxidant in bacteria.  

Science.gov (United States)

Diverse bacteria contain DNA with sulfur incorporated stereo-specifically into their DNA backbone at specific sequences (phosphorothioation). We found that in vitro oxidation of phosphorothioate (PT) DNA by hydrogen peroxide (H(2)O(2)) or peracetic acid has two possible outcomes: DNA backbone cleavage or sulfur removal resulting in restoration of normal DNA backbone. The physiological relevance of this redox reaction was investigated by challenging PT DNA hosting Salmonella enterica cells using H(2)O(2). DNA phosphorothioation was found to correlate with increasing resistance to the growth inhibition by H(2)O(2). Resistance to H(2)O(2) was abolished when each of the three dnd genes, required for phosphorothioation, was inactivated. In vivo, PT DNA is more resistant to the double-strand break damage caused by H(2)O(2) than PT-free DNA. Furthermore, sulfur on the modified DNA was consumed and the DNA was converted to PT-free state when the bacteria were incubated with H(2)O(2). These findings are consistent with a hypothesis that phosphorothioation modification endows DNA with reducing chemical property, which protects the hosting bacteria against peroxide, explaining why this modification is maintained by diverse bacteria. PMID:22772986

Xie, Xinqiang; Liang, Jingdan; Pu, Tianning; Xu, Fei; Yao, Fen; Yang, Yan; Zhao, Yi-Lei; You, Delin; Zhou, Xiufen; Deng, Zixin; Wang, Zhijun

2012-07-05

217

Phosphorothioate DNA as an antioxidant in bacteria.  

UK PubMed Central (United Kingdom)

Diverse bacteria contain DNA with sulfur incorporated stereo-specifically into their DNA backbone at specific sequences (phosphorothioation). We found that in vitro oxidation of phosphorothioate (PT) DNA by hydrogen peroxide (H(2)O(2)) or peracetic acid has two possible outcomes: DNA backbone cleavage or sulfur removal resulting in restoration of normal DNA backbone. The physiological relevance of this redox reaction was investigated by challenging PT DNA hosting Salmonella enterica cells using H(2)O(2). DNA phosphorothioation was found to correlate with increasing resistance to the growth inhibition by H(2)O(2). Resistance to H(2)O(2) was abolished when each of the three dnd genes, required for phosphorothioation, was inactivated. In vivo, PT DNA is more resistant to the double-strand break damage caused by H(2)O(2) than PT-free DNA. Furthermore, sulfur on the modified DNA was consumed and the DNA was converted to PT-free state when the bacteria were incubated with H(2)O(2). These findings are consistent with a hypothesis that phosphorothioation modification endows DNA with reducing chemical property, which protects the hosting bacteria against peroxide, explaining why this modification is maintained by diverse bacteria.

Xie X; Liang J; Pu T; Xu F; Yao F; Yang Y; Zhao YL; You D; Zhou X; Deng Z; Wang Z

2012-10-01

218

Green networking  

CERN Document Server

This book focuses on green networking, which is an important topic for the scientific community composed of engineers, academics, researchers and industrialists working in the networking field. Reducing the environmental impact of the communications infrastructure has become essential with the ever increasing cost of energy and the need for reducing global CO2 emissions to protect our environment.Recent advances and future directions in green networking are presented in this book, including energy efficient networks (wired networks, wireless networks, mobile networks), adaptive networ

Krief, Francine

2012-01-01

219

[Application of selected microorganisms for organic sulfur removal from coal]. Quarterly progress report, March 15, 1989--June 15, 1989  

Energy Technology Data Exchange (ETDEWEB)

Research continues on methods using microorganisms to desulfurize coal. Topics reported on include: coal procurement and preparation, analytical procedures for characterization of total organic sulfur, organic sulfur removal, screening for 4S+ bacteria, extraction of liquid medium, and bacterial growth with depyritized coal. (VC)

Boyden, B.H.

1989-06-15

220

Microbial desulfurization of organic sulfur in coal  

Energy Technology Data Exchange (ETDEWEB)

Microbial desulfurization of coal before combustion has lower operating costs and is more energy efficient than high-temperature chemical processes. At present, both Thiobacillus and Sulfolobus have been shown capable of converting the inorganic sulfur in coal into a soluble sulfate, which can be washed out. This paper discusses research to developing bacteria able to degrade organic sulfur components. Three groups of organosulfur decomposers have been isolated. The first group isolates is capable of a partial degradation of dibenzothiophene to 3-hydroxy-2-formyl-benzothiophene, but sulfur is not liberated from this compound. The second group is capable of decomposing thiophene acetic acid and produces small amounts of H/sub 2/SO/sub 4/. The third group degrades thiophene carboxylic acid but produces large amounts of H/sub 2/SO/sub 4/. The third group degrades thiophene carboxylic acid but produces large amounts of H/sub 2/SO/sub 4/. Research on the use of Escherichia coli is also discussed.

Klubek, B.; Ochman, M.; Clark, D.

1985-05-01

 
 
 
 
221

Process for forming sulfuric acid  

Energy Technology Data Exchange (ETDEWEB)

An improved electrode is disclosed for the anode in a sulfur cycle hydrogen generation process where sulfur dioxie is oxidized to form sulfuric acid at the anode. The active compound in the electrode is palladium, palladium oxide, an alloy of palladium, or a mixture thereof. The active compound may be deposited on a porous, stable, conductive substrate.

Lu, Wen-Tong P. (Upper St. Clair, PA)

1981-01-01

222

Regeneration of waste sulfuric acid  

Energy Technology Data Exchange (ETDEWEB)

To meet the increasing need of high-octane-number gasoline in Japan today, four sulfuric-acid-process alkylaters have recently been constructed. This construction has increased the importance of disposing of waste sulfuric acid. This report describes the present status of Japan's sulfuric acid industry, focusing on applicable ways of regenerating waste sulfuric acid. Japan's yield of sulfuric acid has been holding almost level at an annual rate of about 650 tons for the past ten years. The report gives a table of yearly changes in the production ratio by raw material and the operation rate of sulfuric acid plants. The report also gives an outline of the reaction of waste sulfuric acid extracted from an alkylater in each process and a partial description of the theory of reaction in the sulfuric acid production process using nitric acid. The report also deals with low-temperature active catalysts and high-temperature durable catalysts and describes a device to regenerate sulfuric acid from waste sulfuric acid and a device to produce sulfuric acid from refined gas, sulfide mineral, and sulfur. The report also roughly describes the newly-developed double-contact system and its features. (12 figs, 9 tabs, 12 refs)

Konishi, Hideki

1988-06-01

223

Sodium sulfur battery seal  

Energy Technology Data Exchange (ETDEWEB)

This invention is directed to a seal for a sodium sulfur battery in which a flexible diaphragm sealing elements respectively engage opposite sides of a ceramic component of the battery which separates an anode compartment from a cathode compartment of the battery.

Topouzian, Armenag (Birmingham, MI)

1980-01-01

224

Accidents with sulfuric acid  

Directory of Open Access Journals (Sweden)

Full Text Available Sulfuric acid is an important industrial and strategic raw material, the production of which is developing on all continents, in many factories in the world and with an annual production of over 160 million tons. On the other hand, the production, transport and usage are very dangerous and demand measures of precaution because the consequences could be catastrophic, and not only at the local level where the accident would happen. Accidents that have been publicly recorded during the last eighteen years (from 1988 till the beginning of 2006) are analyzed in this paper. It is very alarming data that, according to all the recorded accidents, over 1.6 million tons of sulfuric acid were exuded. Although water transport is the safest (only 16.38% of the total amount of accidents) in that way 98.88% of the total amount of sulfuric acid was exuded into the environment. Human factor was the common factor in all the accidents, whether there was enough control of the production process, of reservoirs or transportation tanks or the transport was done by inadequate (old) tanks, or the accidents arose from human factor (inadequate speed, lock of caution etc). The fact is that huge energy, sacrifice and courage were involved in the recovery from accidents where rescue teams and fire brigades showed great courage to prevent real environmental catastrophes and very often they lost their lives during the events. So, the phrase that sulfuric acid is a real "environmental bomb" has become clearer.

Rajkovi? Miloš B.

2006-01-01

225

Sulfur in the atmosphere  

Energy Technology Data Exchange (ETDEWEB)

The chapter gives an overview of sulfur compounds found in the atmosphere. It reviews sources of emissions (anthropogenic emissions, biomass burning and natural emissions), chemical transformations and mechanisms, and deposition. The possible implications for global climate change are discussed. 92 refs., 7 figs., 6 tabs.

Berresheim, H.; Wine, P.H.; Davis, D.D. [Georgia Institute of Technology, Atlanta, GA (United States)

1995-12-31

226

SULFUR POLYMER ENCAPSULATION.  

Energy Technology Data Exchange (ETDEWEB)

Sulfur polymer cement (SPC) is a thermoplastic polymer consisting of 95 wt% elemental sulfur and 5 wt% organic modifiers to enhance long-term durability. SPC was originally developed by the U.S. Bureau of Mines as an alternative to hydraulic cement for construction applications. Previous attempts to use elemental sulfur as a construction material in the chemical industry failed due to premature degradation. These failures were caused by the internal stresses that result from changes in crystalline structure upon cooling of the material. By reacting elemental sulfur with organic polymers, the Bureau of Mines developed a product that successfully suppresses the solid phase transition and significantly improves the stability of the product. SPC, originally named modified sulfur cement, is produced from readily available, inexpensive waste sulfur derived from desulfurization of both flue gases and petroleum. The commercial production of SPC is licensed in the United States by Martin Resources (Odessa, Texas) and is marketed under the trade name Chement 2000. It is sold in granular form and is relatively inexpensive ({approx}$0.10 to 0.12/lb). Application of SPC for the treatment of radioactive, hazardous, and mixed wastes was initially developed and patented by Brookhaven National Laboratory (BNL) in the mid-1980s (Kalb and Colombo, 1985; Colombo et al., 1997). The process was subsequently investigated by the Commission of the European Communities (Van Dalen and Rijpkema, 1989), Idaho National Engineering Laboratory (Darnell, 1991), and Oak Ridge National Laboratory (Mattus and Mattus, 1994). SPC has been used primarily in microencapsulation applications but can also be used for macroencapsulation of waste. SPC microencapsulation has been demonstrated to be an effective treatment for a wide variety of wastes, including incinerator hearth and fly ash; aqueous concentrates such as sulfates, borates, and chlorides; blowdown solutions; soils; and sludges. It is not recommended for treatment of wastes containing high concentrations of nitrates because of potentially dangerous reactions between sulfur, nitrate, and trace quantities of organics. Recently, the process has been adapted for the treatment of liquid elemental mercury and mercury contaminated soil and debris.

KALB, P.

2001-08-22

227

SULFUR POLYMER ENCAPSULATION  

International Nuclear Information System (INIS)

[en] Sulfur polymer cement (SPC) is a thermoplastic polymer consisting of 95 wt% elemental sulfur and 5 wt% organic modifiers to enhance long-term durability. SPC was originally developed by the U.S. Bureau of Mines as an alternative to hydraulic cement for construction applications. Previous attempts to use elemental sulfur as a construction material in the chemical industry failed due to premature degradation. These failures were caused by the internal stresses that result from changes in crystalline structure upon cooling of the material. By reacting elemental sulfur with organic polymers, the Bureau of Mines developed a product that successfully suppresses the solid phase transition and significantly improves the stability of the product. SPC, originally named modified sulfur cement, is produced from readily available, inexpensive waste sulfur derived from desulfurization of both flue gases and petroleum. The commercial production of SPC is licensed in the United States by Martin Resources (Odessa, Texas) and is marketed under the trade name Chement 2000. It is sold in granular form and is relatively inexpensive ((approx)$0.10 to 0.12/lb). Application of SPC for the treatment of radioactive, hazardous, and mixed wastes was initially developed and patented by Brookhaven National Laboratory (BNL) in the mid-1980s (Kalb and Colombo, 1985; Colombo et al., 1997). The process was subsequently investigated by the Commission of the European Communities (Van Dalen and Rijpkema, 1989), Idaho National Engineering Laboratory (Darnell, 1991), and Oak Ridge National Laboratory (Mattus and Mattus, 1994). SPC has been used primarily in microencapsulation applications but can also be used for macroencapsulation of waste. SPC microencapsulation has been demonstrated to be an effective treatment for a wide variety of wastes, including incinerator hearth and fly ash; aqueous concentrates such as sulfates, borates, and chlorides; blowdown solutions; soils; and sludges. It is not recommended for treatment of wastes containing high concentrations of nitrates because of potentially dangerous reactions between sulfur, nitrate, and trace quantities of organics. Recently, the process has been adapted for the treatment of liquid elemental mercury and mercury contaminated soil and debris

2001-01-01

228

Biotic and abiotic carbon to sulfur bond cleavage. Final report  

Energy Technology Data Exchange (ETDEWEB)

The microbial desulfurization of organosulfur compounds occurs by unprecedented and largely unexplored biochemical processes. A study of such biotic desulfurizations can be expected to give rise to new and useful chemistry and enzymology. The potential value of understanding and harnessing these processes is seen in relation to the need for methods for the removal of organically bound sulfur from coal and the degradation of organic sulfur-containing pollutants. This research effort has been directed towards an examination of desulfurization ability in well characterized microorganisms, the isolation of bacteria with desulfurization ability from natural sources, the characterization and mechanistic evaluation of the observed biocatalytic processes, the development of biomimetic synthetic organic chemistry based on biotic desulfurization mechanisms and the design and preparation of improved coal model compounds for use in microbial selection processes. A systematic approach to studying biodesulfurizations was undertaken in which organosulfur compounds have been broken down into classes based on the oxidation state of the sulfur atom and the structure of the rest of the organic material. Microbes have been evaluated in terms of ability to degrade organosulfur compounds with sulfur in its sulfonic acid oxidation state. These compounds are likely intermediates in coal desulfurization and are present in the environment as persistent pollutants in the form of detergents. It is known that oxygen bonded to sulfur lowers the carbon-sulfur bond energy, providing a thermodynamic basis for starting with this class of compounds.

Frost, J.W.

1994-05-01

229

Green pioneers.  

UK PubMed Central (United Kingdom)

The government has set tough targets for the NHS in England to reduce its carbon footprint. In this article, nurses and managers at Nottinghamshire Healthcare NHS Trust explain how a programme of 'greening' initiatives - including a trial of electric cars for community staff - have slashed the trust's CO2 output.

Trueland J

2013-05-01

230

Green light for green power  

Energy Technology Data Exchange (ETDEWEB)

One of the consequences of electric industry deregulation in Alberta, the availability of green energy, i.e. energy generated from renewable sources, is discussed. The choice will be available to people in Edmonton and Calgary initially, but based on interest in green power in Europe, where it has been available for some time, it is expected that competition among electricity retailers will be such as to ensure eventual availability in other parts of the province, as well. Regardless of the source, all power produced in Alberta will go into the Interconnected Provincial Power Grid, which will act as the clearinghouse to distribute the mixed power throughout the province. Green power purchases (less than 5 per cent today) will displace power that would otherwise have been produced by non-renewable sources, such as coal or natural gas. As more consumers become environmentally conscious and decide to do their part in protecting the environment by switching to green power, the combustion of fossil fuels and the associated emission of greenhouse gases will decline. The hope and expectation is that more and more people will opt for green power which will encourage energy suppliers to pursue more sustainable fuels, which will result in coal as a source of electrical energy becoming obsolete. In Alberta, many of the details remain to be worked out, but deregulation will make consumers more energy conscious and both ENMAX and EPCOR (the Calgary and Edmonton power utilities, respectively) are taking steps to be ready to respond to the demand for green power, which will inevitably develop.

Sanderson, K.

2000-11-01

231

Apparatus and method for the desulfurization of petroleum by bacteria  

Energy Technology Data Exchange (ETDEWEB)

A method for treating petroleum with anaerobic microorganisms acting as biocatalysts that can remove sulfur atoms from hydrocarbon molecules, under anaerobic conditions, and then convert the sulfur atoms to hydrogen sulfide. The microorganisms utilized are from the family known as the "Sulfate Reducing Bacteria." These bacteria generate metabolic energy from the oxidation of organic compounds, but use oxidized forms of sulfur as an electron acceptor. Because the biocatalyst is present in the form of bacteria in an aqueous suspension, whereas the reacting substrate consists of hydrocarbon molecules in an organic phase, the actual desulfurization reaction takes place at the aqueous-organic interphase. To ensure adequate interfacial contacting and mass transfer, a biphasic electrostatic bioreactor system is utilized. The bioreactor is utilized to disperse and recoalesce a biocatalyst contained in the aqueous liquid phase into the organic liquid phase containing the sulfur. High-intensity electrical fields rupture the aqueous drops into a plurality of microdroplets and induce continuous coalescence and redispersion as the microdroplets travel through the organic phase, thus increasing surface area. As the aqueous microdroplets progress through the organic phase, the biocatalyst then reacts with the sulfur to produce hydrogen sulfide which is then removed from the bioreactor. The organic liquid, now free of the sulfur, is ready for immediate use or further processing.

Lizama, Hector M. (Knoxville, TN); Scott, Timothy C. (Knoxville, TN); Scott, Charles D. (Oak Ridge, TN)

1995-01-01

232

Development of Efficient Flowsheet and Transient Modeling for Nuclear Heat Coupled Sulfur Iodine Cyclefor Hydrogen Production  

Energy Technology Data Exchange (ETDEWEB)

The realization of the hydrogen as an energy carrier for future power sources relies on a practical method of producing hydrogen in large scale with no emission of green house gases. Hydrogen is an energy carrier which can be produced by a thermochemical water splitting process. The Sulfur-Iodine (SI) process is an example of a water splitting method using iodine and sulfur as recycling agents.

Shripad T. Revankar; Nicholas R. Brown; Cheikhou Kane; Seungmin Oh

2010-05-01

233

Sulfur recovery - Cenovus, Foster Creek  

Energy Technology Data Exchange (ETDEWEB)

Government regulations on sulfur levels in gas have constricted oil and gas industries to develop and implement facilities along their transportation and refining infrastructures capable of recovering sulfur efficiently from circulating gas and oil. This presentation shows the process of sulfur recovery with the issues and possible solutions applied at a Cenovus facility in Foster Creek. Sulfur recovery is made possible by use of scavenger products, which react with existing sulfur. These scavenger chemicals play a crucial role in efficiency and unwanted residual solid deposition in sulfur recovery units. Since January 2010, given a decrease in sulfur recovery efficiency, technical investigations have been conducted simultaneously in-situ and in an Alberta sulfur research facility to determine the most cost effective scavenger materials to use. Reasonable solid deposition is observed when the unit is opened. Future steps in improving sulfur recovery cover the selection of regenerative recovery systems with 90% sulfur removal, independent of sulfur species. Some suitable alternative processes are presented and compared as possible future possibilities.

Allende-Garcia, Roberto [Cenovus (Canada)

2011-07-01

234

Acidophilic, heterotrophic bacteria of acidic mine waters  

Energy Technology Data Exchange (ETDEWEB)

Obligately acidophilic, heterotrophic bacteria were isolated both from enrichment cultures developed with acidic mine water and from natural mine drainage. The bacteria were grouped by the ability to utilize a number of organic acids as sole carbon sources. None of the strains were capable of chemolithotrophic growth on inorganic reduced iron and sulfur compounds. All bacteria were rod shaped, gram negative, nonencapsulated, motile, capable of growth at pH 2.6 but not at pH 6.0, catalase and oxidase positive, strictly aerobic, and capable of growth on citric acid. The bacteria were cultivatable on solid nutrient media only if agarose was employed as the hardening agent. Bacterial densities in natural mine waters ranged from approximately 20 to 250 cells per ml, depending upon source and culture medium.

Wichlacz, P.L.; Unz, R.F.

1981-05-01

235

Bacteria and Acidic Drainage from Coal Refuse: Inhibition by Sodium Lauryl Sulfate and Sodium Benzoate  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The application of an aqueous solution of sodium lauryl sulfate and sodium benzoate to the surface of high-sulfur coal refuse resulted in the inhibition of iron-and sulfur-oxidizing chemoautotrophic bacteria and in the decrease of acidic drainage from the refuse, suggesting that acid drainage can be...

Dugan, Patrick R.; Apel, William A.

236

Membrane damage of bacteria by silanols treatment  

Scientific Electronic Library Online (English)

Full Text Available Abstract in english Antimicrobial action of silanols, a new class of antimicrobials, was investigated by transmission electron microscopy and fluorescent dye studies. Gram-negative bacteria, Escherichia coli and Pseudomonas aeruginosa and Gram-positive bacteria, Staphylococcus aureus and Enterococcus faecalis were treated by silanols at concentration of less than 0.2 wt% for one hour. Membrane damage of the bacteria by the silanol treatment was clearly observed by transmission electron micro (more) scopy. Separation of the cytoplasmic membrane from the outer membrane for E. coli and disorganized cytoplasmic membrane of the Gram-positive bacteria were observed when compared to the control. Fluorescent dyes, green-fluorescent nucleic acid stain (Syto 9) and the red-fluorescent nucleic acid stain (Propidium iodide), were used to monitor membrane damage of the bacteria by Confocal microscopy and Spectrophotometer. A reduction of the green fluorescent emission was detected for silanol treated bacteria indicating membrane damage of the bacteria and supporting the hypothesis that their viability loss may be due to their membrane damage analogus to alcohols

Kim, Yun-mi; Farrah, Samuel; Baney, Ronald H

2007-04-01

237

SOAPSTOCK HYDROLYSIS AND ACIDULATION BY ACIDOGENIC BACTERIA  

UK PubMed Central (United Kingdom)

Methods for acidification of soapstock using acids produced by fermentation with acidogenic bacteria and recovery of acidulated fatty acids are disclosed. Soapstock is advantageously acidified by fermentation of endogenous soapstock nutrients and added nutrients under controlled conditions using acidogenic bacteria. The nutrients may include carbohydrate, nitrogen, phosphorous, sulfur from defined or undefined sources. The acidification reaction avoids the use of strong acids for the treatment of soapstock, minimizes wastewater contamination with salts and produces potentially valuable by-products including lactic acid, acetic acid, glyceric acid and nutrient rich microorganisms.

REANEY Martin J. T.

238

Soapstock hydrolysis and acidulation by acidogenic bacteria  

UK PubMed Central (United Kingdom)

Methods for acidification of soapstock using acids produced by fermentation with acidogenic bacteria and recovery of acidulated fatty acids are disclosed. Soapstock is advantageously acidified by fermentation of endogenous soapstock nutrients and added nutrients under controlled conditions using acidogenic bacteria. The nutrients may include carbohydrate, nitrogen, phosphorous, sulfur from defined or undefined sources. The acidification reaction avoids the use of strong acids for the treatment of soapstock, minimizes wastewater contamination with salts and produces potentially valuable by-products including lactic acid, acetic acid, glyceric acid and nutrient rich microorganisms.

REANEY MARTIN J T

239

Green Computing  

Directory of Open Access Journals (Sweden)

Full Text Available Green computing is all about using computers in a smarter and eco-friendly way. It is the environmentally responsible use of computers and related resources which includes the implementation of energy-efficient central processing units, servers and peripherals as well as reduced resource consumption and proper disposal of electronic waste .Computers certainly make up a large part of many people lives and traditionally are extremely damaging to the environment. Manufacturers of computer and its parts have been espousing the green cause to help protect environment from computers and electronic waste in any way.Research continues into key areas such as making the use of computers as energy-efficient as Possible, and designing algorithms and systems for efficiency-related computer technologies.

K. Shalini; K. Naga Prasanthi

2013-01-01

240

Sulfur in gasoline  

Energy Technology Data Exchange (ETDEWEB)

The international refiner is presently being squeezed by narrow refining margins and ever increasing demands for improved product quality. One high visibility aspect of this quality is the amount of sulfur allowed in motor gasoline under present and future regulations. This limit alone will call for fundamental changes in refining strategy, as well as require large capital investments. This paper will review the interaction of hydrotreating and FCC technologies, with the goal of describing that will be necessary to economically meet the gasoline sulfur limits in the coming years. The interaction with other upstream and downstream refinery operations will be considered within the boarder scope of total refinery products needed in the decade of reformulated fuels.

Pearce, J.R.; Keyworth, D.; Desai, P.H. [Akzo Chemicals Inc., Pasadena, TX (United States)

1993-12-31

 
 
 
 
241

Green Gold  

International Nuclear Information System (INIS)

The main purpose of this work is to offer a general panoramic of the processes or experiences pilot that are carried out in the Project Green Gold, as strategy of environmental sustainability and organizational invigoration in Choco, especially in the 12 communities of the municipalities of Tado and Condoto. It is also sought to offer a minimum of information on the techniques of handmade production and to show the possibilities to carry out in a rational way the use and use of the natural resources. The Project Green Gold is carried out by the Corporation Green Gold (COV) and co-financed with resources of international and national character, the intervention of the financial resources it achievement mainly for the use of clean processes in the extraction stages and metals benefit. The project is centered primarily in the absence of use of products or toxic substances as the mercury, fair trade, organizational invigoration, execution of 11 approaches and certification of the metals Gold and Platinum. The COV, it has come executing the proposal from the year 2001 with the premise of contributing to the balance between the rational exploitation of the natural resources and the conservation of the environment in the Choco. In the project they are used technical handmade characteristic of the region framed inside the mining activity and production activities are diversified in the productive family units. Those producing with the support of entities of juridical character, specify the necessary game rules for the extraction and products commercialization

2004-01-01

242

Stratospheric sulfur oxidation kinetics  

Energy Technology Data Exchange (ETDEWEB)

Oxidation of SO2 to H2SO4 in the atmosphere is believed to involve the reaction of SO3 with water. It is commonly assumed that this is an important step leading to homogeneous nucleation of H2SO4 aerosol particles. Heterogeneous chemistry on sulfuric acid aerosols regulate much of the ozone photochemistry in the lower stratosphere and are also believed to have significant effect on the climate. Understanding aerosol loading requires a detailed knowledge of the stratospheric sulfur budget, including its oxidation kinetics. Here we present results of a laboratory project studying a key step in the oxidation process, the homogeneous reaction between SO3 and H2O vapor. Kinetic measurements are performed in a high-pressure turbulent fast-flow reactor (fabricated at MIT) which minimizes heterogeneous loss of SO3 on reactorwalls. The rate of decay of SO3 and the appearance of H2SO4 is monitored in the presence of excess water vapor. Gas phase reactants and products are detected via an atmospheric pressure chemical ionization mass spectrometer which is coupled to the exit of the flow reactor. Sulfuric acid nucleation studies can also be performed using the turbulent flow reactor. Initial measurements using a particle detector (based on Mie scattering) showed that aerosol formation and particle size distribution are controlled by varying the SO3/H2O gas ratio and the reactor temperature. Results for the reaction SO3J+ H2O show a second order dependence in water vapor density and a strong negative temperature dependence. The results, measured in the range -30C to +95C, imply that an SO3.H2O adduct and/or a water dimer species is likely involved in the reaction mechanism. Results of recent theoretical calculations on the SO3 + H2O system also support the finding that two water molecules are involved. Implications for the gas phase production of sulfuric acid in the atmosphere will be discussed.

Jayne, J.T.; Worsnop, D.R.; Kolb, C.E. [Aerodyne Research, Inc., Billerica, MA (United States)] [and others

1995-12-31

243

Advanced Sulfur Control Processing  

Energy Technology Data Exchange (ETDEWEB)

The primary objective of this project is to determine the feasibility of an alternate concept for the regeneration of high temperature desulfurization sorbents in which elemental sulfur, instead of SO{sub 2}, is produced. If successful, this concept will eliminate or alleviate problems caused by the highly exothermic nature of the regeneration reaction, the tendency for metal sulfate formation, and the need to treat the regeneration off-gas to prevent atmospheric SO{sub 2}, emissions. Iron and cerium-based sorbents were chosen on the basis of thermodynamic analysis to determine the feasibility of elemental sulfur production. The ability of both to remove H{sub 2}S during the sulfidation phase is less than that of zinc-based sorbents, and a two-stage desulfurization process will likely be required. Preliminary experimental work used electrobalance reactors to compare the relative rates of reaction of O{sub 2} and H{sub 2}O with FeS. More detailed studies of the regeneration of FeS as well as the sulfidation of CeO{sub 2} and regeneration of Ce{sub 2}O{sub 2}S are being carried out in a laboratory-scale fixed-bed reactor equipped with a unique analytical system which permits semi-continuous analysis of the distribution of elemental sulfur, H{sub 2}S, and SO{sub 2} in the reaction product gas.

Gangwal, S.K.; Portzer, J.W.; Turk, B.S.; Gupta, R. [Research Triangle Inst., Research Triangle Park, NC (United States)

1996-12-31

244

Beyond the sulfur effect  

Energy Technology Data Exchange (ETDEWEB)

The addition of reactive elements (REs) is known to increase the adherence of Al{sub 2}O{sub 3} scales and the underlying alloys. A widely accepted mechanism is that the REs getter the sulfur impurity in the alloy, thus preventing it from segregating to the scale-alloy interface to weaken the interfacial bonding. This paper provides evidence showing that not all S-free interfaces are strong. Although eliminating the sulfur in the alloy can greatly improve scale adhesion, the presence of RE clearly has additional beneficial effects that make the scale-alloy interface even stronger. Fe{sub 3}Al-base alloys, with or without Zr additions or a desulfurization H{sub 2}-anneal were oxidized at 1000 C in O{sub 2}. The amount of sulfur at the Al{sub 2}O{sub 3}-alloy interface was studied after the scales were removed by scratching with a diamond stylus in ultra-high vacuum using Auger spectroscopy. The interface composition was related to the spallation resistance of the scale.

Hou, P.Y. [Lawrence Berkeley National Lab., CA (United States). Materials Science Div.

1999-10-01

245

Monitoring of bacteria in acid mine environments by reverse genome probing  

Energy Technology Data Exchange (ETDEWEB)

Traditionally, the study of microbial biodiversity in acid mine drainage (AMD) environments focused on species belonging to the genus Thiobacillus, but various other bacteria such as Leptospirillum ferroxidans, as well as certain fungi, flagellates, green algae, and yeasts have also been observed as minor constituents of microbiota in AMD. The purpose of this investigation was to apply reverse sample genome probing (RSGP) to the detection of acidophilic bacteria commonly recovered from AMD sites, and to describe the community of such environments. Analysis of enriched environmental samples by RSGP indicated that T. ferroxidans was enriched by a ferrous sulfate medium; although all thiobacilli grew in sulfur medium, T. thioxidans strains were the most prominent. Enrichment in glucose medium resulted in the selection of T. acidophilus strains. Analysis of DNA extracted without enrichment, from cells recovered from AMD water or sediment, showed that the major community components were homologous with T. ferroxidans and with T. acidophilus. A minority of community components showed similarity to T. thioxidans; none exhibited homology with L. ferroxidans. These results indicate that RSGP is a useful tool for monitoring microorganisms in AMD environments. There is also reason to believe that a better understanding of the effectiveness of different treatments of AMD could be obtained by using RSGP analysis to compare samples from treated and untreated acid mine effluents. 39 refs., 2 tabs., 5 figs.

Leveille, S. A.; Leduc, L. G.; Ferroni, G. D. [Laurentian Univ., Dept. of Biology, Sudbury, ON (Canada); Telang, A. J.; Voordouw, G. [Calgary Univ., Dept. of Biological Sciences, AB (Canada)

2001-05-01

246

Response of tomato to sulfur nutrition and sulfur dioxide  

Energy Technology Data Exchange (ETDEWEB)

Tomato plants, cultivar Fireball, were grown with 1.6, 16 or 80 ppm (mg per litre) sulfate-S in nutrient solution added daily to the rooting medium. Exposure to 0.1 ppm gaseous sulfur dioxide had no significant effect on growth variables. Exposure to 0.4 ppm sulfur dioxide decreased leaf area. The uptake of sulfur dioxide followed a diurnal pattern that was similar for all sulfate-S levels. Exposure to 0.1 or 0.4 ppm sulfur dioxide resulted in significant increases in both total S and sulfate-S. The ratio of sulfate-S to total S increased after 0.4 ppm sulfur dioxide exposure. Comparison of actual total S content with that predicted on the basis of uptake of sulfur dioxide indicated a loss of S from plants exposed to 0.4 ppm sulfur dioxide. For plants supplied with 1.6 ppm S, exposure to 0.1 ppm sulfur dioxide increased chlorophyll a content while plants receiving 80 ppm S had decreased chlorophyll a and b following 0.1 ppm sulfur dioxide exposure. (A.V.)

Stratigakos, A.; Ormrod, D.P.

1985-01-01

247

Draft genome sequence of the sulfur-oxidizing bacterium "Candidatus Sulfurovum sediminum" AR, which belongs to the Epsilonproteobacteria.  

UK PubMed Central (United Kingdom)

Sulfur-oxidizing bacteria are common microorganisms in a variety of sulfide-rich environments. They play important roles in the global sulfur cycle on earth. Here, we present a high-quality draft genome sequence of a sulfur-oxidizing bacterium, "Candidatus Sulfurovum sediminum" strain AR, which belongs to the class Epsilonproteobacteria and dominated an enrichment culture from a marine sediment collected off Svalbard, within the Arctic Circle. Its genome contains genes for sulfur oxidation and carbon fixation. The size of the draft genome is 2.12 Mb, and the G+C content is 39.4%.

Park SJ; Ghai R; Martín-Cuadrado AB; Rodríguez-Valera F; Jung MY; Kim JG; Rhee SK

2012-08-01

248

Rumen bacteria  

International Nuclear Information System (INIS)

The rumen is the most extensively studied gut community and is characterized by its high population density, wide diversity and complexity of interactions. This complex, mixed microbial culture is comprised of prokaryote organisms including methane-producing archaebacteria, eukaryote organisms, such as ciliate and flagellate protozoa, anaerobic phycomycete fungi and bacteriophage. Bacteria are predominant (up to 1011 viable cells per g comprising 200 species) but a variety of ciliate protozoa occur widely (104-106/g distributed over 25 genera). The anaerobic fungi are also widely distributed (zoospore population densities of 102-104/g distributed over 5 genera). The occurrence of bacteriophage is well documented (107-109 particles/g). This section focuses primarily on the widely used methods for the cultivation and the enumeration of rumen microbes, especially bacteria, which grow under anaerobic conditions. Methods that can be used to measure hydrolytic enzymes (cellulases, xylanases, amylases and proteinases) are also described, along with cell harvesting and fractionation procedures. Brief reference is also made to fungi and protozoa, but detailed explanations for culturing and enumerating these microbes is presented in Chapters 2.4 and 2.5

2005-01-01

249

Microbial stabilization of sulfur-laden sorbents. Technical report, December 1, 1992--February 29, 1993  

Energy Technology Data Exchange (ETDEWEB)

Clean coal technologies that involve limestone for in situ sulfur capture generate lime/limestone products laden with sulfur at various oxidation states. If sulfur is completely stabilized as sulfate, the spent sorbent is ready for commercial utilization as gypsum. However, the presence of reduced sulfur species requires additional processing. Thermal oxidation of reduced sulfur frequently results in undesirable release of SO{sub 2}. Microbial oxidation may provide an inexpensive and effective alternative. Sorbents laden with reduced forms of sulfur such as sulfide or sulfite can serve as growth substrates for sulfur-oxidizing bacteria, which convert all sulfur to sulfate. The goals of this project are to optimize conditions for sulfate generation from sulfide and sulfite on prepared lime/limestone mixtures; to test and optimize the effectiveness of microbial processing on spent sorbents from coal gasification, in-duct sorbent injection, and fluidized bed combustion; and to search for hyperalkalinophilic thiobacilli, which would be effective up to pH 11. We report here progress toward controlling the pH of culture media, and determining the highest pH at which several environmental isolates and named strains could initiate sulfur oxidation.

Miller, K.W. [Illinois State Univ., Normal, IL (United States); Banerjee, D. [Illinois Clean Coal Inst., Carterville, IL (United States)

1993-05-01

250

Green Corridor green energy partnerships  

Energy Technology Data Exchange (ETDEWEB)

The Green Corridor refers to 2 kilometres of multi-lane roadway in Windsor, Ontario, including the Ambassador Bridge crossing over the Detroit River to the United States. This bi-national trade route serves about 12,000 trucks per day and handles 40 per cent of Canada-US trade. The route passes through a large residential community with a concentrated business area, several schools and the University of Windsor campus. Residents are experiencing significant environmental impacts and are voicing concerns about quality of life which is compromised by pedestrian safety concerns, poor sightlines, and dominance of the transportation infrastructure. Negative impacts include soil, air, and noise pollution along with ecological stressors. The Corridor imparts a negative first impression for those arriving in Canada for trade, business and tourism. An aesthetic, educational and environmentally sound redevelopment of this Corridor would have impacts at the community, the city and the national levels. For these reasons, a sustainable environmental redevelopment of the designated Green Corridor was launched. The Green Corridor redevelopment involves the local creative, residential, educational, and business communities in re-imaging and transforming the currently disadvantaged environment. Green Corridor will achieve this through a series of publicly engaging research projects that combine environmental, social sciences research, art, and commercial development along the trade route. Community residents and visitors will experience a new conception of the urban landscape, shifting from a concrete mass to a regenerative green zone where landscape and environmental education are emphasized through an educational wetlands project at a local high school and provisions for environmental research at the University of Windsor. The redevelopment project serves as a model for proposed projects of wind and river turbines in which educational opportunities will be funded by research grants and partner donations while construction costs will be absorbed by public, industrial or commercial partners. The proposed nature bridge demonstrates the extent to which this collaborative exchange of ideas and shared responsibilities can work toward the development of viable, lasting contributions from the arts to a community. 1 ref., 4 figs.

Strickland, R. [Windsor Univ., ON (Canada). School of Visual Arts; Harding, N. [Noel Harding Studio, Toronto, ON (Canada)

2006-07-01

251

Isolation of an aerobic sulfur oxidizer from the SUP05/Arctic96BD-19 clade.  

UK PubMed Central (United Kingdom)

Bacteria from the uncultured SUP05/Arctic96BD-19 clade of gamma proteobacterial sulfur oxidizers (GSOs) have the genetic potential to oxidize reduced sulfur and fix carbon in the tissues of clams and mussels, in oxygen minimum zones and throughout the deep ocean (>200?m). Here, we report isolation of the first cultured representative from this GSO clade. Closely related cultures were obtained from surface waters in Puget Sound and from the deep chlorophyll maximum in the North Pacific gyre. Pure cultures grow aerobically on natural seawater media, oxidize sulfur, and reach higher final cell densities when glucose and thiosulfate are added to the media. This suggests that aerobic sulfur oxidation enhances organic carbon utilization in the oceans. The first isolate from the SUP05/Arctic96BD-19 clade was given the provisional taxonomic assignment 'Candidatus: Thioglobus singularis', alluding to the clade's known role in sulfur oxidation and the isolate's planktonic lifestyle.

Marshall KT; Morris RM

2013-02-01

252

Green Buildings  

Science.gov (United States)

From the Department of Energy's Center of Excellence for Sustainable Development, this Green Buildings site serves as a detailed metapage for environmentally conscious architects, engineers, and builders. As the introduction to the site points out, "The design, construction, and maintenance of buildings has a tremendous impact on our environment and our natural resources." The site offers carefully summarized links to relevant Websites and publications on topics such as building principles, building programs, rating systems, affordable housing, codes/ordinances, educational materials, and more. This site may be of interest to those who want practical applications for protecting the environment.

2000-01-01

253

Production of sulfuric acid and installation therefor  

Digital Repository Infrastructure Vision for European Research (DRIVER)

In the production of sulfuric acid by (a) oxidizing a sulfurous material with an oxidant to obtain sulfur dioxide, (b) catalytically oxidizing this with oxygen to obtain sulfur trioxide and (c) producing sulfuric acid and a waste gas, at least part of the waste gas is recycled to the first step. The...

Arpentinier, Philippe; Dumont, Marie-Noëlle; Kalitventzeff, Boris

254

Sulfur solidification and handling systems  

Energy Technology Data Exchange (ETDEWEB)

The article focuses on the Sandvik Rotoform system for handling solidified sulfur extracted from the feedstocks used for producing clean fuels. The benefits of the process (in which the sulfur is made into pastilles) are listed. The process is described and is said to be efficient and environmentally friendly. Diagrams show (a) the sulfur handling scheme; (b) the Sandvik Rotoform system and (c) uses of sulfur. The process is claimed to be ideal for refineries and has been well proven at all the major refineries in China and India.

Gehrmann, Stefan [Sandvik Process Systems (Germany)

2000-05-01

255

Acidophilic sulfur disproportionation  

Science.gov (United States)

Bacterial disproportionation of elemental sulfur (S0) is a well-studied metabolism and is not previously reported to occur at pH values less than 4.5. In this study, a sediment core from an abandoned-coal-mine-waste deposit in Southwest Indiana revealed sulfur isotope fractionations between S0 and pyrite (?34Ses-py) of up to -35‰, inferred to indicate intense recycling of S0 via bacterial disproportionation and sulfide oxidation. Additionally, the chemistry of seasonally collected pore-water profiles were found to vary, with pore-water pH ranging from 2.2 to 3.8 and observed seasonal redox shifts expressed as abrupt transitions from Fe(III) to Fe(II) dominated conditions, often controlled by fluctuating water table depths. S0 is a common product during the oxidation of pyrite, a process known to generate acidic waters during weathering and production of acid mine drainage. The H2S product of S0 disproportionation, fractionated by up to -8.6‰, is rapidly oxidized to S0 near redox gradients via reaction with Fe(III) allowing for the accumulation of isotopically light S0 that can then become subject to further sulfur disproportionation. A mass-balance model for S0 incorporating pyrite oxidation, S0 disproportionation, and S0 oxidation readily explains the range of observed ?34Ses-py and emphasizes the necessity of seasonally varying pyrite weathering and metabolic rates, as indicated by the pore water chemistry. The findings of this research suggest that S0 disproportionation is potentially a common microbial process at a pH sulfate reduction.

Hardisty, Dalton S.; Olyphant, Greg A.; Bell, Jonathan B.; Johnson, Adam P.; Pratt, Lisa M.

2013-07-01

256

Green chemistry  

International Nuclear Information System (INIS)

A grand challenge facing government, industry, and academia in the relationship of our technological society to the environment is reinventing the use of materials. To address this challenge, collaboration from an interdisciplinary group of stakeholders will be necessary. Traditionally, the approach to risk management of materials and chemicals has been through inerventions intended to reduce exposure to materials that are hazardous to health and the environment. In 1990, the Pollution Prevention Act encouraged a new tact-elimination of hazards at the source. An emerging approach to this grand challenge seeks to embed the diverse set of environmental perspectives and interests in the everyday practice of the people most responsible for using and creating new materials--chemists. The approach, which has come to be known as Green Chemistry, intends to eliminate intrinsic hazard itself, rather than focusing on reducing risk by minimizing exposure. This chapter addresses the representation of downstream environmental stakeholder interests in the upstream everyday practice that is reinventing chemistry and its material inputs, products, and waste as described in the '12 Principles of Green Chemistry'

2004-01-01

257

Green chemistry  

International Nuclear Information System (INIS)

The depletion of world fossil fuel reserves and the involvement of greenhouse gases in the global warming has led to change the industrial and energy policies of most developed countries. The goal is now to reserve petroleum to the uses where it cannot be substituted, to implement renewable raw materials obtained from plants cultivation, and to consider the biodegradability of molecules and of manufactured objects by integrating the lifetime concept in their expected cycle of use. The green chemistry includes the design, development and elaboration of chemical products and processes with the aim of reducing or eliminating the use and generation of harmful compounds for the health and the environment, by adapting the present day operation modes of the chemical industry to the larger framework of the sustainable development. In addition to biofuels, this book reviews the applications of green chemistry in the different industrial processes in concern. Part 1 presents the diversity of the molecules coming from renewable carbon, in particular lignocellulose and the biotechnological processes. Part 2 is devoted to materials and treats of the overall available technological solutions. Part 3 focusses on functional molecules and chemical intermediates, in particular in sugar- and fats-chemistry. Part 4 treats of biofuels under the aspects of their production and use in today's technologies. The last part deals with the global approaches at the environmental and agricultural levels. (J.S.)

2006-01-01

258

Imbalances in sulfur assimilation and synthesis of sulfur-containing amino acids: Visualization at the single-cell level.  

UK PubMed Central (United Kingdom)

We describe genetically encoded sensors which transmit elevated cytosolic concentrations of O-acetyl serine (OAS) and O-acetyl homoserine (OAH) - intermediates of L-cysteine and L-methionine synthesis - into an optical output. The sensor pSenOAS3 elicits a 7.5-fold increased fluorescence in cultures of a Corynebacterium glutamicum strain that excrete L-cysteine. Determination of the cytosolic OAS concentration revealed an increase up to 0.13 mM, whereas the concentration in the reference strain was below the detection limit, indicating that incorporation of assimilatory sulfur is limited in the strain studied. In another strain, overexpression of metX-encoding homoserine acetyltransferase resulted in an 8-fold increase in culture fluorescence at a cytosolic OAH concentration of 0.76 mM. We also assayed for consequences of extracellular sulfur supply and observed a graded fluorescence increase at decreasing sulfur concentrations below 400 ?M. Overall, this demonstrates the usefulness of the sensors for monitoring intracellular sulfur availability. The sensors also enable monitoring at the single-cell level, and since related and close homologs of the transcription factor used in the constructed sensors are widespread among bacteria, this technology offers a new possibility of assaying in vivo for sulfur limitation, and to do this at the single-cell level.

Hoffmann K; Grünberger A; Lausberg F; Bott M; Eggeling L

2013-08-01

259

Process for removing sulfur from sulfur-containing gases  

Energy Technology Data Exchange (ETDEWEB)

The present disclosure relates to improved processes for treating hot sulfur-containing flue gas to remove sulfur therefrom. Processes in accorda The government may own certain rights in the present invention pursuant to EPA Cooperative Agreement CR 81-1531.

Rochelle, Gary T. (Austin, TX); Jozewicz, Wojciech (Chapel Hill, NC)

1989-01-01

260

Sulfuric acid as autocatalyst in the formation of sulfuric acid.  

UK PubMed Central (United Kingdom)

Sulfuric acid can act as a catalyst of its own formation. We have carried out a computational investigation on the gas-phase formation of H(2)SO(4) by hydrolysis of SO(3) involving one and two water molecules, and also in the presence of sulfuric acid and its complexes with one and two water molecules. The hydrolysis of SO(3) requires the concurrence of two water molecules, one of them acting as a catalyzer, and our results predict an important catalytic effect, ranging between 3 and 11 kcal·mol(-1) when the catalytic water molecule is substituted by a sulfuric acid molecule or one of its hydrates. In these cases, the reaction products are either bare sulfuric acid dimer or sulfuric acid dimer complexed with a water molecule. There are broad implications from these new findings. The results of the present investigation show that the catalytic effect of sulfuric acid in the SO(3) hydrolysis can be important in the Earth's stratosphere, in the heterogeneous formation of sulfuric acid and in the formation of aerosols, in H(2)SO(4) formation by aircraft engines, and also in understanding the formation of sulfuric acid in the atmosphere of Venus.

Torrent-Sucarrat M; Francisco JS; Anglada JM

2012-12-01

 
 
 
 
261

The Green Power Network: Buying Green Power  

Science.gov (United States)

The Green Power Network (GPN), operated and maintained by the National Renewable Energy Laboratory for the U.S. Department of Energy, provides news and information on green power markets and related activities. Here, they supply a great tool for discovering green power availability throughout the United States. Clicking on any state will provide visitors with any green power including utility green pricing programs, retail green power products offered in competitive utility markets, and renewable energy certificate products (REC) sold separate from electricity. This will be a useful tool for instructors or students interested in renewable energy technologies.

2008-10-21

262

Phylogenetic and functional diversity of Bacteria and Archaea in a unique stratified lagoon, the Clipperton atoll (N Pacific).  

UK PubMed Central (United Kingdom)

The Clipperton lagoon in the North Pacific Ocean has been isolated from the surrounding sea for c. 160 years. It has a stratified water column that comprises an oxic and brackish upper water layer (mixolimnion) and a deep sulfuric anoxic saline layer (monimolimnion), separated by a steep pycnocline. Here, we test whether the Clipperton lagoon with its distinctive physico-chemical features, geographic isolation, recent water column stratification, and large nutrient input harbors original microbial communities. The combination of capillary electrophoresis single-strand polymorphism (CE-SSCP) fingerprinting and sequencing of cloned bacterial and archaeal 16S rRNA genes, and functional genes for methanogenesis (mcrA), methanotrophy (pmoA), and sulfate reduction (dsrAB), revealed that microbial communities and pathways were highly stratified down the water column. The mixolimnion contained ubiquitous freshwater clades of Alpha- and Betaproteobacteria, while the pycnocline contained mostly green sulfur bacteria (phylum Chlorobi). Sequences of the upper layers were closely related to sequences found in other aquatic ecosystems, suggesting that they have a strong potential for dispersal and colonization. In contrast, the monimolimnion contained new deeply branching bacterial divisions within the OP11 cluster and the Bacteroidetes, and was the most diverse of the layers. The unique environmental conditions characterizing the deep layers of the lagoon may explain the novelty of the microbial communities found at the Clipperton atoll.

Galand PE; Bourrain M; De Maistre E; Catala P; Desdevises Y; Elifantz H; Kirchman DL; Lebaron P

2012-01-01

263

Expand sulfur plant capacity  

Energy Technology Data Exchange (ETDEWEB)

Interest in oxygen use to expand existing Claus sulfur plants in refineries has been building ever since high oxygen concentrations were successfully used at the Conoco, Lake Charles La., refinery, and the KOA, Kawasaki refinery in Japan. This interest increased recently due to the demand created by numerous refinery hydrotreater projects, driven by more stringent fuel quality and sulfur emission standards, as well as the economic incentive to process low-cost heavy, sour crudes. Various approaches that introduce low oxygen levels have resulted in moderate capacity increases. Oxygen can be added to the air supply stream for concentrations up to 30% oxygen. Beyond the 30% oxygen level, oxygen must be introduced into the reaction furnace through a burner specifically designed to accommodate oxygen, or through a separate oxygen lance. However, higher oxygen concentrations result in higher temperatures, which rapidly approach the furnace refractory design limits. Methods must be employed to mitigate the reaction furnace temperature whenever high oxygen levels are necessary to coincide with significant capacity increases in refinery operations. Three proprietary technologies are in commercial operation that successfully address this issue.

Hull, R. [BOC Gases, Murray Hill, NJ (United States); Watson, R. [BOC Gases, Guildford (United Kingdom); Chow, T.K. [Ralph M Parsons Co., Pasadena, CA (United States)] [and others

1995-09-01

264

Sulfur capture mechanisms  

Energy Technology Data Exchange (ETDEWEB)

The Morgantown Energy Technology Center is currently involved in developing high-temperature cleanup for the integrated gasification combined cycle process. Solid sorbents are being employed to remove sulfur-bearing gases. Therefore, it is important to know the reaction mechanisms and kinetics of the interactions of the sulfur-bearing gases with sorbent materials, and the changes in elemental composition during reactions in order to develop novel sorbents and/or to improve existing sorbents. In our previous work (1,2,3) the mechanisms of the reactions of CaO with SO[sub 2]/O[sub 2], zinc titanate with H[sub 2]S/CO and H[sub 2] and elemental changes in zinc copper ferrite during heating were investigated. It was found that the CaO reaction proceeds via CaSO[sub 3] an intermediate while in the zinc titanate reaction ZnSO[sub 4] was formed as an intermediate. Migration of copper to the surface and presence of copper in the +1 state was observed in zinc copper ferrite at 823K. In the present work, the characterization of fresh, sulfided and regenerated zinc titanate sorbents, and the mechanism of sulfate formation during regeneration of zinc sulfide were investigated. X-Ray photoelectron spectroscopy (XPS), Scanning electron microscopy/Electron dispersive analysis (SEWEDS), and Fourier transform infra-red spectroscopy (FTIR) were used to analyze intermediates and products during the reaction.

Siriwardane, R.V.; Poston, J.A.; Woodruff, S.D.

1992-01-01

265

Green business will remain green  

International Nuclear Information System (INIS)

It all started with two words. Climate change. The carbon dioxide trading scheme, which was the politicians' idea on solving the number one global problem, followed. Four years ago, when the project was begun, there was no data for project initiation. Quotas for polluters mainly from energy production and other energy demanding industries were distributed based on spreadsheets, maximum output and expected future development of economies. Slovak companies have had a chance to profit from these arrangements since 2005. Many of them took advantage of the situation and turned the excessive quotas into an extraordinary profit which often reached hundreds of million Sk. The fact that the price of free quotas offered for sale dropped basically to 0 in 2006 only proved that the initial distribution was too generous. And the market reacted to the first official measurements of emissions. Slovak companies also contributed to this development. However, when planning the maximum emission volumes for 2008-2012 period, in spite of the fact that actual data were available, their expectations were not realistic. A glance at the figures in the proposal of the Ministry of Environment is sufficient to realize that there will be no major change in the future. And so for many Slovak companies business with a green future will remain green for the next five years. The state decided to give to selected companies even more free space as far as emissions are concerned. The most privileged companies can expect quotas increased by tens of percent. (author)

266

Malachite green interferes with postantibiotic recovery of mycobacteria.  

UK PubMed Central (United Kingdom)

The genus Mycobacterium comprises slow-growing species with generation times ranging from hours to weeks. The protracted incubation time before colonies appear on solid culture medium can result in overgrowth by faster-growing microorganisms. To prevent contamination, the solid media used in laboratories and clinics for cultivation of mycobacteria contain the arylmethane compound malachite green, which has broad-spectrum antimicrobial activity. Malachite green has no impact on the plating efficiency of mycobacteria when cells are grown under normal conditions. However, we found that malachite green interfered with colony formation when bacteria were preexposed to antibiotics targeting cell wall biogenesis (isoniazid, ethionamide, ethambutol). This inhibitory effect of malachite green was not observed when bacteria were preexposed to antibiotics targeting cellular processes other than cell wall biogenesis (rifampin, moxifloxacin, streptomycin). Sputum specimens from tuberculosis patients are routinely evaluated on solid culture medium containing high concentrations of malachite green. This practice could lead to underestimation of bacterial loads and overestimation of chemotherapeutic efficacy.

Gelman E; McKinney JD; Dhar N

2012-07-01

267

Green Revolution  

Science.gov (United States)

Coming up with better ways to get where we need to go and power the lives we live requires development of new technologies, along with research to help us minimize the impact of these technologies on our environment. The overall goal of this series is to encourage people to ask questions and look beyond fossil fuels for innovative solutions to our ever-growing energy needs. Interest in science and technology provides the necessary foundation for our future in a world powered by clean energy. The series also provides insight into what careers in science, engineering and other topics related to clean energy technologies are really like. There are videos about wind, solar, green roofs, smart grid, biomass, microbes and city cars.

268

Volume efficient sodium sulfur battery  

Energy Technology Data Exchange (ETDEWEB)

In accordance with the teachings of this specification, a sodium sulfur battery is formed as follows. A plurality of box shaped sulfur electrodes are provided, the outer surfaces of which are defined by an electrolyte material. Each of the electrodes have length and width dimensions substantially greater than the thicknesses thereof as well as upwardly facing surface and a downwardly facing surface. An electrode structure is contained in each of the sulfur electrodes. A holding structure is provided for holding the plurality of sulfur electrodes in a stacked condition with the upwardly facing surface of one sulfur electrode in facing relationship to the downwardly facing surface of another sulfur electrode thereabove. A small thickness dimension separates each of the stacked electrodes thereby defining between each pair of sulfur electrodes a volume which receives the sodium reactant. A reservoir is provided for containing sodium. A manifold structure interconnects the volumes between the sulfur electrodes and the reservoir. A metering structure controls the flow of sodium between the reservoir and the manifold structure.

Mikkor, Mati (Ann Arbor, MI)

1980-01-01

269

Questions on sulfur. Part 1  

Energy Technology Data Exchange (ETDEWEB)

Designers must consider a number of fundamental choices for each of the key units in a sulfur-recovery complex: sour-gas treating, sour-water treating, Claus sulfur plant, and tail-gas treater. A review of these choices provides a clear basis for developing the design philosophy for the complex.

Parnell, D.

1981-04-01

270

Process for preparing sulfur granules  

Energy Technology Data Exchange (ETDEWEB)

This invention relates to a process for the preparation of sulfur granules, in which in a granulation zone a sulfur melt is, with the aid of at least one feeding device, supplied in an upward direction into a bed of of sulfur nuclei. These nuclei are kept separate from each other and are contacted with a gas. The process is characterized in that a sulfur melt having a temperature of at least 5/sup 0/C above the crystallization temperature is introduced into a bed of sulfur nuclei having a temperature of 30-70/sup 0/C. The bed is fluidized with a gas, and the melt, after having left the feeding device, is contacted with a powerful gas stream having a temperature about equal to the temperature of the melt and a velocity of at least 100 m/s, in such an amount that the mass ratio of the gas stream to the sulfur melt is between 0.1 : 1 and 0.6 : 1. The sulfur granules formed are continuously discharged from the granulation zone. The process provides a more efficient production of sulfur granules having improved properties and reduces agglomeration of granules in the bed.

Slangen, H.J.M.; Hoek, C.

1988-09-20

271

Sulfur production continues to rise  

Energy Technology Data Exchange (ETDEWEB)

Sulfur is one of the world's most-popular commodities. It has another distinctive feature: most of it is produced from the effluent of chemical process plants. A lot more sulfur will have similar origins in the future as countries tighten up on sulfur emissions in a global effort to reduce acid rain. To meet such stricter controls, new sulfur recovery methods are being developed, and existing ones improved, to extract sulfur more efficiently and cheaply. Among the new developments are improvements in the Claus process--and alternatives to Claus--for the extraction of hydrogen sulfide (H[sub 2]S) from process streams; and new ways to recover elemental sulfur from sulfur dioxide (SO[sub 2]) contained in the flue gas of coal-fired plants. Currently, the common flue gas treatment is scrubbing with limestone or lime, but this produces millions of tons/yr of gypsum sludge that is mostly landfilled. Gypsum can be processed into wallboard, but that market is limited. The paper discusses the use of flue gas as a raw material; a versatile acid production process; alternative processes for H[sub 2]S extraction; and a process that recovers both sulfur and hydrogen.

Parkinson, G.; Ondrey, G.; Moore, S.

1994-06-01

272

Assimilatory Sulfur Metabolism in Marine Microorganisms: Considerations for the Application of Sulfate Incorporation into Protein as a Measurement of Natural Population Protein Synthesis †  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The sulfur content of residue protein was determined for pure cultures of Nitrosococcus oceanus, Desulfovibrio salexigens, 4 mixed populations of fermentative bacteria, 22 samples from mixed natural population enrichments, and 11 nutritionally and morphologically distinct isolates from enrichments o...

Cuhel, Russell L.; Taylor, Craig D.; Jannasch, Holger W.

273

Transfrontier sulfur emissions in Europe  

Energy Technology Data Exchange (ETDEWEB)

The paper deals with the formation of EMEP, the Cooperative Programme for Monitoring and Evaluation of Long-Range Transmission of Air Pollutants in Europe, the structure of the latter, the EMEP sulfur measuring network. 91 differently structured monitoring stations participate in the program. Six maps facilitate access to the sulfur measuring results. In the EMEP region, 1985 sulfur emissions amounted to approximately 22651 kt, deposits were in the order of magnitude of 15132 kt. A comparative evaluation shows the Federal Republic of Germany to have been confronted with 1200 kt sulfur emissions and 723 kt sulfur deposits in the same year, 46% of which were domestic and 54 imported emissions. At the same time, about 868 kt were transmitted from the Federal Republic of Germany to adjacent countries. (orig./HSCH).

Pankrath, J.

1987-12-01

274

Green’s Symmetries in Finite Digraphs  

Directory of Open Access Journals (Sweden)

Full Text Available The semigroup DV of digraphs on a set V of n labeled vertices is defined. It is shown that DV is faithfully represented by the semigroup Bn of n ´ n Boolean matrices and that the Green’s L, R, H, and D equivalence classifications of digraphs in DV follow directly from the Green’s classifications already established for Bn. The new results found from this are: (i) L, R, and H equivalent digraphs contain sets of vertices with identical neighborhoods which remain invariant under certain one-sided semigroup multiplications that transform one digraph into another within the same equivalence class, i.e., these digraphs exhibit Green’s isoneighborhood symmetries; and (ii) D equivalent digraphs are characterized by isomorphic inclusion lattices that are generated by their out-neighborhoods and which are preserved under certain two-sided semigroup multiplications that transform digraphs within the same D equivalence class, i.e., these digraphs are characterized by Green’s isolattice symmetries. As a simple illustrative example, the Green’s classification of all digraphs on two vertices is presented and the associated Green’s symmetries are identified.

Allen D. Parks

2011-01-01

275

Microbial stabilization of sulfur-laden sorbents. Technical report, 1 December 1993--28 February 1994  

Energy Technology Data Exchange (ETDEWEB)

Clean coal technologies that involve limestone for sulfur capture generate lime/limestone products laden with sulfur at various oxidation states. If sulfur is completely stabilized as sulfate, the spend sorbent is ready for commercial utilization as gypsum. However, the presence of reduced sulfur species required additional processing. Thermal oxidation of reduced sulfur can result in undesirable release of SO{sub 2}. Microbial oxidation might provide an inexpensive and effective alternative. Sorbents laden with reduced forms of sulfur such as sulfide, sulfite, or various polythionate species serve as growth substrates for sulfur-oxidizing bacteria, which have the potential to convert all sulfur to sulfate. This quarter, efforts focused on treating the aqueous phase of a waste sorbent obtained from an inhibited wet scrubbing process. Although two named strains, Thiobacillus neapolitanus ATCC 23639 and ATCC 23641, failed; the isolate TQ1 rapidly oxidized thiosalts, producing sulfate. The Virtis Fermentor arrived, so that experiments with TQ1 have been scaled up to 1.5 liters with temperature, aeration, and pH control.

Miller, K.W. [Illinois State Univ., Normal, IL (United States)

1994-06-01

276

Sulfur monitor analyzer  

Energy Technology Data Exchange (ETDEWEB)

A sulfur monitor analyzer is disclosed and utilizes a burner or flame holder, a burner or reaction chamber, a photomultiplier tube, a light collimator, and chopper blade members with openings so as to permit a flame disposed in the burner or reaction chamber to be seen by the photomultiplier tube at all times. A chemiluminescent radiation mask is disposed operatively between a portion of the chemiluminescent radiation and the photomultiplier tube so as to provide a chopper open mode of operation at which time the photomultiplier tube receives the flame radiation and a fraction of any chemiluminescent radiation surrounding the flames with any remaining fraction of any chemiluminescent radiation being obscured permanently by the chemiluminescent radiation mask. When the chopper is in the closed mode of operation, the photomultiplier tube receives only the radiation from the flame through an aperture defined by an opening in the opaque segment of this chopper or chemiluminescent radiation mask.

Etess, E.

1980-02-26

277

Antimicrobial activity of sulfur compounds derived from cabbage.  

UK PubMed Central (United Kingdom)

Selected sulfur compounds found in cabbage and its fermentation product, sauerkraut, were tested for minimum inhibitory concentration (MIC) against growth of 15 species of bacteria and 4 species of yeasts. S-Methyl-L-cysteine sulfoxide, sinigrin, and dimethyl sulfide at 500 ppm were not inhibitory to any of the bacteria and yeasts tested. Dimethyl disulfide at 500 ppm retarded some, but did not prevent growth of any of the test microorganisms. Dimethyl trisulfide had an MIC to bacteria of 200 ppm and to yeast of 20 ppm. Methyl methanethiosulfinate had an MIC between 50 and 200 ppm for all bacteria, and between 6 and 10 ppm for all yeasts tested. Methyl methanethiosulfonate had an MIC between 20 and 100 ppm for bacteria and between 50 and 500 ppm for yeasts. Allyl isothiocyanate had an MIC between 50 and 500 ppm for bacteria and between 1 and 4 ppm for yeasts. Methyl methanethiosulfinate was 10 to 100 times more inhibitory against Listeria monocytogenes at pH values of 5, 6, and 7 and was much less influenced by pH than was sodium benzoate.

Kyung KH; Fleming HP

1997-01-01

278

Isolation and characterization of bacteria on the drainage water from Ratones mine and its behaviour on pyrite  

International Nuclear Information System (INIS)

This paper describes some of the studies made about iron and sulfur oxidizing bacteria on the drainage water from Ratones mine. Different liquid and solid media were utilized as well as some energy sources, ferrous sulphate, thiosulfate and sulfur. Some experiment were al so realized on museum grade pyrite aimed at determining the possibilities of applying the mentioned bacteria on the leaching of pyrite and subsequently on the leaching of uranium ores. (Author) 27 refs.

1974-01-01

279

Green chromatography.  

UK PubMed Central (United Kingdom)

Analysis of organic compounds in samples characterized by different composition of the matrix is very important in many areas. A vast majority of organic compound determinations are performed using gas or liquid chromatographic methods. It is thus very important that these methods have negligible environmental impact. Chromatographic techniques have the potential to be greener at all steps of the analysis, from sample collection and preparation to separation and final determination. The paper summarizes the approaches used to accomplish the goals of green chromatography. While complete elimination of sample preparation would be an ideal approach, it is not always practical. Solventless extraction techniques offer a very good alternative. Where solvents must be used, the focus should be on the minimization of their consumption. The approaches used to make chromatographic separations greener differ depending on the type of chromatography. In gas chromatography it is advisable to move away from using helium as the carrier gas because it is a non-renewable resource. GC separations using low thermal mass technology can be greener because of energy savings offered by this technology. In liquid chromatography the focus should be on the reduction of solvent consumption and replacement of toxic and environmentally hazardous solvents with more benign alternatives. Multidimensional separation techniques have the potential to make the analysis greener in both GC and LC. The environmental impact of the method is often determined by the location of the instrument with respect to the sample collection point.

P?otka J; Tobiszewski M; Sulej AM; Kupska M; Górecki T; Namie?nik J

2013-09-01

280

EPA Green Buildings  

Science.gov (United States)

The Environmental Protection Agency's site contains a wealth of information on green guilding: green-built schools, residences, and office buildings. This site also describes what EPA is doing to green its own buildings. Topics such as energy efficiency, indoor environment, and sustainable development are covered on the Green Buildings website.

2008-09-12

 
 
 
 
281

What is green?  

Energy Technology Data Exchange (ETDEWEB)

The definition of Green as it pertains to Green Chemicals or Green Corrosion Inhibition seems to be vague. Even though the scientific and engineering communities use this word frequently, there seems to be a lack of consensus on the definition. The paper describes the various definitions and their overall impact on Green.

Satyanarayana, D.V. [Gupta Canadian Fracmaster Ltd., Calgary, Alberta (Canada)

1998-12-31

282

The purification of elemental sulfur  

Energy Technology Data Exchange (ETDEWEB)

Sulfur has been purified by a dynamic pyrolysis procedure that takes into account the unique viscosity-temperature relationship of the liquid. An apparatus is described that incorporates gas-bubbling and rocking to overcome diffusion-limited kinetics. For the first time, a mechanism is proposed for the pyrolytic purification of sulfur based upon Carsul formation and the H{sub 2}S{leftrightarrow}H{sub 2}S{sub {ital x}} equilibrium. Infrared methods are delineated for qualitative analysis and quantitative estimates of anion contaminants, including the omnipresent hydrocarbon impurities. Our purified sulfur has a total carbon, oxygen, and hydrogen impurity level of {lt}10 {mu}g/g.

Susman, S.; Rowland, S.C.; Volin, K.J. (Materials Science Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States))

1992-06-01

283

Sulfur redox chemistry governs diurnal antimony and arsenic cycles at Champagne Pool, Waiotapu, New Zealand  

Science.gov (United States)

Champagne Pool, a sulfidic hot spring in New Zealand, exhibits distinct diurnal variations in antimony (Sb) and arsenic (As) concentrations, with daytime high and night-time low concentrations. To identify the underlying mobilization mechanisms, five sites along the drainage channel of Champagne Pool were sampled every 2 h during a 24 h period. Temporal variations in elemental concentrations and Sb, As, and sulfur (S) speciation were monitored in the discharging fluid. Total trace element concentrations in filtered and unfiltered samples were analyzed using ICP-MS, and Sb, As and S species were determined by IC-ICP-MS. Sulfur speciation in the drainage channel was dominated by thiosulfate and sulfide at night, while sulfate dominated during the day. The distinct diurnal changes suggest that the transformations are caused by phototrophic sulfur-oxidizing bacteria. These bacteria metabolize thiosulfate and sulfide in daylight to form sulfate and, as suggested by modeling with PhreeqC, elemental sulfur. Sulfide consumption during the day results in undersaturation of antimony sulfides, which triggers the additional release of dissolved Sb. For As, diurnal cycles were much more pronounced in speciation than in total concentrations, with di- and trithioarsenate forming at night due to excess sulfide, and monothioarsenate forming from arsenite and elemental sulfur during the day. Sulfur speciation was thus found to control Sb and As in terms of both solubility and speciation.

Ullrich, Maria K.; Pope, James G.; Seward, Terry M.; Wilson, Nathaniel; Planer-Friedrich, Britta

2013-07-01

284

Why green power?  

Energy Technology Data Exchange (ETDEWEB)

The concept of green power and green pricing was discussed. Green power has come to mean renewable energy technologies that generate electricity without impacts such as toxic emissions, water pollution, thermal emissions, waste products, and land impacts. Large hydroelectric power generation does not constitute green power. Green power represents wind energy, solar photovoltaics and run of river small hydro. Green power marketing is predicated on the assumption that consumers would be willing to pay a premium to ensure that green energy is on the electrical grids. Green energy will be marketed differently to residential, commercial or industrial customer, depending on whether or not emission credits are issued. Green power is not yet offered in Canada. It was suggested that in order to promote the concept, the Federal Government must show leadership and consumers must demonstrate their commitment by signing up for green energy and vote with their dollars.

Edworthy, J. [Nor`Wester Energy Systems Ltd., Calgary, AB (Canada)

1997-06-01

285

Induction of Purple Sulfur Bacterial Growth in Dairy Wastewater Lagoons by Circulation  

Science.gov (United States)

Aims: To determine if circulation of diary wastewater induces the growth of phototrophic purple sulfur bacteria (PSB). Methods and Results: Two dairy wastewater lagoons that were similar in size, geographic location, number and type of cattle loading the lagoons were chosen. The only obvious diffe...

286

DEGRADATION KINETICS OF MONOSACCHARIDES IN HYDROCHLORIC, SULFURIC, AND SULFUROUS ACID  

Directory of Open Access Journals (Sweden)

Full Text Available The degradation kinetics of monosaccharides during sulfurous acid treatment was compared to hydrochloric acid and to sulfuric acid treatments. Reaction conditions corresponded to the range found in previous research to allow for the production of hemicelluloses-derived monosaccharides through hydrolysis of wood. Degradation behavior of monosaccharides during treatment with each acid was expressed by a second-order reaction rate constant with respect to substrate and acid concentrations, and the activation energy and frequency factor were calculated using the Arrhenius equation. Results demonstrated that the second-order reaction rate of a monosaccharide was dependent on the type of acid, indicating that monosaccharides degrade at different rates under different acids, even when the molar concentration of the acid is the same. The degradation of monosaccharides in sulfurous acid was much slower than that in hydrochloric acid and in sulfuric acid. A comparison of two sequential treatments with sulfuric acid, with and without the bisulfite ion, showed that sulfurous acid has a protective effect on the degradation of monosaccharides.

Yan Shi,; Tomoya Yokoyama,; Takuya Akiyama,; Makoto Yashiro,; Yuji Matsumoto

2012-01-01

287

Production of sulfur from sulfur dioxide obtained from flue gas  

Energy Technology Data Exchange (ETDEWEB)

This patent describes a regenerable process for recovery of elemental sulfur from a gas containing sulfur dioxide comprising the steps of: contacting the gas with an aqueous, alkaline reaction medium containing sodium sulfite in concentration sufficient so that a slurry containing solid sodium sulfide is formed to react sulfur dioxide with sodium sulfite to form a solution containing dissolved sodium pyrosulfite and sodium sulfite; separating sulfur dioxide from the solution produced to leave a residual mixture containing water, sodium sulfite and a sodium pyrosulfite, the amount of sulfur dioxide separated being equal to about one-third the amount of sulfur dioxide which reacted with sodium sulfite; adding, in substantial absence of air, sufficient water and sodium bicarbonate to the residual mixture to react with the dissolved sodium pyrsulfide and form a slurry of solid sodium sulfite suspended in the resulting aqueous, alkaline reaction medium and gaseous carbon dioxide; separating the gaseous carbon dioxide; separating the solid sodium sulfite from the aqueous alkaline reaction medium and recycling the separated reaction medium; reducing the separated sodium sulfite to sodium sulfide; adding the sodium sulfide to an aqueous reaction medium containing sodium bicarbonate and, in the substantial absence of air, carbonating the resulting mixture with the gaseous carbon dioxide to form a slurry of solid particles of sodium bicarbonate dispersed in an aqueous reactor medium containing sodium bicarbonate, along with a gas composed primarily of hydrogen sulfide.

Miller, R.

1989-06-06

288

The Museum of Bacteria  

Science.gov (United States)

The Museum of Bacteria serves as a clearinghouse of Web links on bacteria and bacteriology and also provides "crystal-clear information about many aspects of bacteria." The Museum of Bacteria is provided by the Foundation of Bacteria, a non-profit organization dedicated to promoting the field of bacteriology. Links are selected for a general audience, although one section is geared toward professionals in the field. Some of the latest features of the Museum are an "exhibit" on the good bacteria found in food and a Student Hall where students can present their own bacteria-related projects.

289

Stereoscopic green building block  

UK PubMed Central (United Kingdom)

The utility model discloses a stereoscopic green building block, which comprises a rectangular base formed by fixedly connecting an upper green body and a lower green body. Both the upper green body and the lower green body are rectangular, the lower green body is three to five times as thick as the upper green body, a recess is arranged on the upper surface of the lower green body, a grass seed layer and a soil layer are arranged inside the recess sequentially from top to bottom, a through hole is diagonally and downwardly arranged on the lateral side of the lower green body and communicated with the recess, and a water outlet hole through the lower surface of the lower green body is arranged at the lowest position at the bottom of the recess. The stereoscopic green building block is simple in structure, low in cost, integrally composed of the upper green body and the lower green body, easy in processing and demouding, and simple in forming, and the grass seed layer and the soil layer cannot be scoured away by rainwater. The stereoscopic green building block is small in occupied area and large in green area, and environment can be beautified effectively.

LE LI

290

Dissimilatory sulfur cycling in oxygen minimum zones: an emerging metagenomics perspective.  

UK PubMed Central (United Kingdom)

Biological diversity in marine OMZs (oxygen minimum zones) is dominated by a complex community of bacteria and archaea whose anaerobic metabolisms mediate key steps in global nitrogen and carbon cycles. Molecular and physiological studies now confirm that OMZs also support diverse micro-organisms capable of utilizing inorganic sulfur compounds for energy metabolism. The present review focuses specifically on recent metagenomic data that have helped to identify the molecular basis for autotrophic sulfur oxidation with nitrate in the OMZ water column, as well as a cryptic role for heterotrophic sulfate reduction. Interpreted alongside marker gene surveys and process rate measurements, these data suggest an active sulfur cycle with potentially substantial roles in organic carbon input and mineralization and critical links to the OMZ nitrogen cycle. Furthermore, these studies have created a framework for comparing the genomic diversity and ecology of pelagic sulfur-metabolizing communities from diverse low-oxygen regions.

Stewart FJ

2011-12-01

291

Dissimilatory sulfur cycling in oxygen minimum zones: an emerging metagenomics perspective.  

Science.gov (United States)

Biological diversity in marine OMZs (oxygen minimum zones) is dominated by a complex community of bacteria and archaea whose anaerobic metabolisms mediate key steps in global nitrogen and carbon cycles. Molecular and physiological studies now confirm that OMZs also support diverse micro-organisms capable of utilizing inorganic sulfur compounds for energy metabolism. The present review focuses specifically on recent metagenomic data that have helped to identify the molecular basis for autotrophic sulfur oxidation with nitrate in the OMZ water column, as well as a cryptic role for heterotrophic sulfate reduction. Interpreted alongside marker gene surveys and process rate measurements, these data suggest an active sulfur cycle with potentially substantial roles in organic carbon input and mineralization and critical links to the OMZ nitrogen cycle. Furthermore, these studies have created a framework for comparing the genomic diversity and ecology of pelagic sulfur-metabolizing communities from diverse low-oxygen regions. PMID:22103540

Stewart, Frank J

2011-12-01

292

Genetic manipulation of acidophilic bacteria  

Energy Technology Data Exchange (ETDEWEB)

Thiobacillus ferrooxidans is important in leaching of metals from mineral ores and in the removal of pyritic sulfur from coal. It is also intimately involved in production of acid mine drainage. Other acidophilic bacteria, including members of the genus Acidiphilium, are usually present in the same environments as T. ferrooxidans, and there is evidence to suggest that these acidophilic heterotrophs may increase the rate of T. ferrooxidans' attack on inorganic sulfides. Our laboratory is studying the genetic characteristics of these acidophilic bacteria and developing techniques for introducing desirable genes into them. Several endogenous plasmids from Acidiphilium strains have been cloned into E. coli vectors. Some of the resulting plasmids are able to confer antibiotic resistance to Acidiphilium after transformation by electroporation. In addition, a broad-host range plasmid conferring resistance to tetracycline has been introduced into Acidiphilium strains by electroporation. This same plasmid, has also been transferred to Acidiphilium from E. coli directly by conjugation. A temperate bacteriophage which infects a number of Acidiphilium isolates has been discovered and partially characterized. It has a lambdoid morphology and a genome of approximately 97 kb, comprised of double-stranded DNA which is probably modified. 16 refs., 2 figs., 4 tabs.

Ward, T.E.; Rowland, M.L.; Glenn, A.W.; Watkins, C.S.; Bruhn, D.F.; Bulmer, D.; Roberto, F.F.

1989-01-01

293

Characterization of iron-sulfur cluster assembly protein IscA from Acidithiobacillus ferrooxidans.  

UK PubMed Central (United Kingdom)

IscA is a key member of the iron-sulfur cluster assembly machinery found in bacteria and eukaryotes, but the mechanism of its function in the biogenesis of iron-sulfur cluster remains elusive. In this paper, we demonstrate that Acidithiobacillus ferrooxidans IscA is a [4Fe-4S] cluster binding protein, and it can bind iron in the presence of DTT with an apparent iron association constant of 4·10(20) M(-1). The iron binding in IscA can be promoted by oxygen through oxidizing ferrous iron to ferric iron. Furthermore, we show that the iron bound form of IscA can be converted to iron-sulfur cluster bound form in the presence of IscS and L-cysteine in vitro. Substitution of the invariant cysteine residues Cys35, Cys99, or Cys101 in IscA abolishes the iron binding activity of the protein; the IscA mutants that fail to bind iron are unable to assemble the iron-sulfur clusters. Further studies indicate that the iron-loaded IscA could act as an iron donor for the assembly of iron-sulfur clusters in the scaffold protein IscU in vitro. Taken together, these findings suggest that A. ferrooxidans IscA is not only an iron-sulfur protein, but also an iron binding protein that can act as an iron donor for biogenesis of iron-sulfur clusters.

Qian L; Zheng C; Liu J

2013-03-01

294

Occurrence and distribution of sulfur in peat-forming environments of southern Florida  

Energy Technology Data Exchange (ETDEWEB)

Cores and surface samples of peats from the Everglades-Mangrove region of southern Florida were analyzed for total sulfur and pyritic sulfur. These values were compared with the petrographic-botanical components of the peats as determined from pointcounts of oriented microtome sections. Pyrite occurs as individual euhedral crystals, loosely packed framboids, and lenses or crusts of minute crystals. Framboids and minute crystals are often associated with organic matter and sometimes with bacteria and fungi. Pyrite tends to selectively occur in void spaces in or between peat tissues. In samples containing very small amounts of pyrite, framboidal pyrite is the prevalent form. Marine to brackish peats contain the highest pyrite and total sulfur contents, with brackish peats generally containing more pyrite than marine peats. Pyrite tends to be lower in all peats within 30 cm of the surface, whether marine or brackish. Burial of freshwater peats beneath marine or brackish peats tends to increase the total sulfur and pyritic sulfur in the underlying peats. Burial beneath brackish-water, clay-rich deposits (such as splays) tends to increase total sulfur and pyritic sulfur in the underlying deposits more than burial beneath less clay-rich deposits. 19 references.

Cohen, A.D.; Spackman, W.; Dolsen, P.

1984-07-01

295

Effect of Thiobacillus, sulfur, and vermicompost on the water-soluble phosphorus of hard rock phosphate.  

Science.gov (United States)

Sulfur, organic matter, and inoculation with sulfur-oxidizing bacteria are considered as amendments to increase the availability of phosphorus from rock phosphate. The present study was conducted to evaluate the best combination of sulfur, vermicompost, and Thiobacillus thiooxidans inoculation with rock phosphate from Yazd province for direct application to agricultural lands in Iran. For such study, an experiment was carried out in a completely randomized design with factorial arrangement: Elemental sulfur originated from Sarakhs mine at three rates, 0% (S1), 10% (S2), 20% (S3), vermicompost at two rates, 0% (V1), 15% (V2), and inoculation without (B1) and with (B2) T. thiooxidans, in three replications. The results showed that water-soluble phosphorus (WSP) content was significantly higher in inoculated treatments compared to non-inoculated treatments. Sulfur had a significant effect on WSP. The highest solubility rate of rock phosphate was obtained in 20% of sulfur (S3) treatments and it was 2.4 times more than S1 treatments. Vermicompost also had a significant and positive effect on WSP of rock phosphate dissolution. The results also revealed that the highest concentration of WSP, sulfate and the lowest pH were obtained in treatments with 20% sulfur, 15% vermicompost inoculated with T. thiooxidans (B2S3V2). PMID:19736005

Aria, Marzieh Mohammady; Lakzian, Amir; Haghnia, Gholam Hosain; Berenji, Ali Reza; Besharati, Hosein; Fotovat, Amir

2009-09-06

296

Effect of Thiobacillus, sulfur, and vermicompost on the water-soluble phosphorus of hard rock phosphate.  

UK PubMed Central (United Kingdom)

Sulfur, organic matter, and inoculation with sulfur-oxidizing bacteria are considered as amendments to increase the availability of phosphorus from rock phosphate. The present study was conducted to evaluate the best combination of sulfur, vermicompost, and Thiobacillus thiooxidans inoculation with rock phosphate from Yazd province for direct application to agricultural lands in Iran. For such study, an experiment was carried out in a completely randomized design with factorial arrangement: Elemental sulfur originated from Sarakhs mine at three rates, 0% (S1), 10% (S2), 20% (S3), vermicompost at two rates, 0% (V1), 15% (V2), and inoculation without (B1) and with (B2) T. thiooxidans, in three replications. The results showed that water-soluble phosphorus (WSP) content was significantly higher in inoculated treatments compared to non-inoculated treatments. Sulfur had a significant effect on WSP. The highest solubility rate of rock phosphate was obtained in 20% of sulfur (S3) treatments and it was 2.4 times more than S1 treatments. Vermicompost also had a significant and positive effect on WSP of rock phosphate dissolution. The results also revealed that the highest concentration of WSP, sulfate and the lowest pH were obtained in treatments with 20% sulfur, 15% vermicompost inoculated with T. thiooxidans (B2S3V2).

Aria MM; Lakzian A; Haghnia GH; Berenji AR; Besharati H; Fotovat A

2010-01-01

297

Mechanism for the formation of elemental sulfur from aqueous sulfide in chemical and microbiological desulfurization processes  

Energy Technology Data Exchange (ETDEWEB)

A detailed reaction mechanism is proposed for the formation of crystalline elemental sulfur from aqueous sulfide by oxidation with transition-metal ions like V{sup 5}, Fe{sup 3}, Cu{sup 2}, etc. The first step is the formation of HS{center_dot} radicals by one-electron oxidation of HS{sup {minus}} ions. These radicals exist at pH values near 7 mainly as S{center_dot}{sup {minus}}. Their spontaneous decay results in the formation of the disulfide ion S{sub 2}{sup 2{minus}}. The further oxidation of disulfide either by S{center_dot}{sup {minus}} radicals or by the transition-metal ions yields higher polysulfide ions from which the homocyclic sulfur molecules S{sub 6}, S{sub 7}, and S{sub 8} are formed. In water these hydrophobic molecules form clusters which grow to droplets of liquid sulfur (sulfur sol). Depending on the composition of the aqueous phase, crystallization of the liquid sulfur as either {alpha}- or {beta}-S{sub 8} is rapid or delayed. Surfactants delay this solidification, while certain cations promote it. All these reactions are proposed to take place in desulfurization plants working by the Stretford, Sulfolin, Lo-Cat, SulFerox, or Bio-SR processes. In addition, the sulfur produced from sulfide by oxidizing sulfur bacteria is formed by the same mechanism, which now explains many observations made previously (including the formation of the byproducts thiosulfate, polythionates, and sulfate).

Steudel, R. [Technische Univ. Berlin (Germany). Inst. fuer Anorganische und Analytische Chemie

1996-04-01

298

METHOD FOR MANUFACTURING KOMBUCHA DRINK USING GREEN TEA  

UK PubMed Central (United Kingdom)

PURPOSE: Provided is a method for manufacturing a kombucha drink using green tea by inoculating oriental tea fungus composed of yeast and acetic acid bacteria into black tea and fermenting it. Therefore, the manufactured kombucha tea has excellent taste and flavor. CONSTITUTION: In a method for manufacturing a kombucha drink using green tea by inoculating oriental tea fungus composed of yeast and acetic acid bacteria into black tea and fermenting it, it is characterized by the steps of: preparing a mixed extract of green tea and black tea by heating 1 part by weight of black tea and 3 part by weight of green tea in water adding 10%(w/v) of saccharide consisting of 80-2 wt.% of sugar and 20-80 wt.% of honey syrup to the mixed extract and culturing it at 30 deg.C for 5 days.

LEE IN SEON; LEE SAM BIN; SO HAN SEOP

299

ACS Green Chemistry Institute  

Science.gov (United States)

This special feature page from the American Chemical Society (ACS) showcases the up-and-coming field of "green chemistry," that is, the development of chemical products and processes that eliminate or reduce the use and generation of hazardous substances. A list of principles behind green chemistry, a searchable bibliography of green chemistry references, and green chemistry links (including conferences). This page comes from ACS's Green Chemistry Project, a three-year educational project to develop and disseminate green chemistry educational materials for graduate and undergraduate chemistry students.

2005-12-13

300

Prevention of the formation of acid drainage from high-sulfur coal, coal refuse, and coal spoils by inhibition of iron and sulfur oxidizing microorganisms. Final report, 1 October 1977-30 June 1981  

Energy Technology Data Exchange (ETDEWEB)

Acid drainage is a problem associated geographically and geologically with the mining industry and is due to production or sulfuric acid from sulfur-containing minerals. The data presented in the report demonstrate that it is possible to inhibit pyrite-oxidizing bacteria in high sulfur coal refuse with a concurrent reduction in acid drainage formed in the refuse. The most effective inhibitors studied are combinations of sodium lauryl sulfate (SLS) plus sodium benzoate (Bz), both of which are relatively nontoxic to higher organisms.

Dugan, P.R.

1985-06-01

 
 
 
 
301

Leaching of zinc sulfide by Thiobacillus ferrooxidans: Bacterial oxidation of the sulfur product layer increases the rate of zinc sulfide dissolution at high concentrations of ferrous ions  

Energy Technology Data Exchange (ETDEWEB)

This paper reports the results of leaching experiments conducted with and without Thiobacillus ferroxidans at the same conditions in solution. The extent of leaching of ZnS with Bacteria is significantly higher than that without bacteria at high concentrations of ferrous ions. A porous layer of elemental sulfur is present on the surfaces of the chemically leached particles, which no sulfur is present on the surfaces of the bacterially leached particles. The analysis of the data using the shrinking-core model shows that the chemical leaching of ZnS is limited by the diffusion of ferrous ions through the sulfur product layer at high concentrations of ferrous ions. The analysis of the data shows that diffusion through the product layer does not limit the rate of dissolution when bacteria are present. This suggests that the action of T.ferroxidans in oxidizing the sulfur formed on the particle surface is to remove the barrier to diffusion by ferrous ions.

Fowler, T.A.; Crundwell, F.K.

1999-12-01

302

Analysis of the sulfur origin and sulfur isotopic compositions of acid rain  

International Nuclear Information System (INIS)

Acid rain has been one of the most serious environment problems in the world and the study of sulfur isotope can help us find the sulfur source, composition and have important significance for research to harness acid rain. This paper mainly revolves around three aspects to introduce the significance of sulfur isotopic study, they are sulfur isotopes in coals, sulfur isotopic compositions of surface water and sulfur isotopes in wheat. (authors)

2006-01-01

303

Correction of lime-induced chlorosis in soybeans in a glasshouse with sulfur and an acidifying iron compound  

Energy Technology Data Exchange (ETDEWEB)

Soybeans were grown in calcareous Hacienda loam soil in which small quantities of amendments to correct iron chlorosis were placed. The amendments used were combinations of sulfur and a waste iron product containing a crystalline form of sulfuric acid. Mixtures of sulfur and the acidifying material produced better prevention of the lime-induced chlorosis than did either product alone. Suggested is that the sulfur-oxidizing bacteria function more efficiently when calcareous soil is acidified than in the original soil. Most effective results were obtained with rates equivalent to 370 kg/ha for the acid iron waste product. Treatment with 185 kg/ha of elemental sulfur gave little response. Control was 24% of maximum response. Iron uptake per plant in leaves was highly correlated with yield, but iron concentration in leaves was not.

Wallace, A; Samman, Y.S.; Wallace, G.A.

1981-12-01

304

Sulfur in agriculture/ Enxofre na agricultura  

Scientific Electronic Library Online (English)

Full Text Available Abstract in portuguese A deficiência de enxofre (S) nos solos vem se tornando cada vez mais comum em várias áreas do mundo em razão de práticas agronômicas, alta exportação de biomassa e redução das emissões atmosféricas. Nesta revisão são abordados a incidência, a exploração comercial e estoques de S na natureza, a importância do S para as plantas, as formas orgânicas e inorgânicas no solo e suas transformações, assim como, principalmente, o processo de oxidação microbi (more) ológica do enxofre elementar (S0) como alternativa para a reposição dos níveis de S do solo. Também é abordada a diversidade de microrganismos oxidantes de S0 nos solos, com destaque para o gênero Thiobacillus, bem como os mecanismos bioquímicos de oxidação do S0 em bactérias. Por fim, foram revisados os principais métodos para determinação da taxa de oxidação do S0 nos solos e as variáveis que influenciam esse processo. Abstract in english Sulfur (S) deficiency in soils is becoming increasingly common in many areas of the world as a result of agronomic practices, high biomass exportation and reduced S emissions to the atmosphere. In this review, the incidence and commercial exploitation of S pools in nature are discussed, as well as the importance of S for plants and the organic and inorganic S forms in soil and their transformations, especially the process of microbiological oxidation of elemental sulfur ( (more) S0) as an alternative to the replenishment of S levels in the soil. The diversity of S0-oxidizing microorganisms in soils, in particular the genus Thiobacillus, and the biochemical mechanisms of S0 oxidation in bacteria were also addressed. Finally, the main methods to measure the S0 oxidation rate in soils and the variables that influence this process were revised.

Lucheta, Adriano Reis; Lambais, Marcio Rodrigues

2012-11-01

305

Sulfur in agriculture Enxofre na agricultura  

Directory of Open Access Journals (Sweden)

Full Text Available Sulfur (S) deficiency in soils is becoming increasingly common in many areas of the world as a result of agronomic practices, high biomass exportation and reduced S emissions to the atmosphere. In this review, the incidence and commercial exploitation of S pools in nature are discussed, as well as the importance of S for plants and the organic and inorganic S forms in soil and their transformations, especially the process of microbiological oxidation of elemental sulfur (S0) as an alternative to the replenishment of S levels in the soil. The diversity of S0-oxidizing microorganisms in soils, in particular the genus Thiobacillus, and the biochemical mechanisms of S0 oxidation in bacteria were also addressed. Finally, the main methods to measure the S0 oxidation rate in soils and the variables that influence this process were revised.A deficiência de enxofre (S) nos solos vem se tornando cada vez mais comum em várias áreas do mundo em razão de práticas agronômicas, alta exportação de biomassa e redução das emissões atmosféricas. Nesta revisão são abordados a incidência, a exploração comercial e estoques de S na natureza, a importância do S para as plantas, as formas orgânicas e inorgânicas no solo e suas transformações, assim como, principalmente, o processo de oxidação microbiológica do enxofre elementar (S0) como alternativa para a reposição dos níveis de S do solo. Também é abordada a diversidade de microrganismos oxidantes de S0 nos solos, com destaque para o gênero Thiobacillus, bem como os mecanismos bioquímicos de oxidação do S0 em bactérias. Por fim, foram revisados os principais métodos para determinação da taxa de oxidação do S0 nos solos e as variáveis que influenciam esse processo.

Adriano Reis Lucheta; Marcio Rodrigues Lambais

2012-01-01

306

Bacteria isolated from amoebae/bacteria consortium  

Energy Technology Data Exchange (ETDEWEB)

New protozoan derived microbial consortia and method for their isolation are provided. Consortia and bacteria isolated therefrom are useful for treating wastes such as trichloroethylene and trinitrotoluene. Consortia, bacteria isolated therefrom, and dispersants isolated therefrom are useful for dispersing hydrocarbons such as oil, creosote, wax, and grease.

Tyndall, Richard L. (Clinton, TN)

1995-01-01

307

Green Vehicle Guide  

Science.gov (United States)

... on, please visit fueleconomy.gov PLEASE NOTE: The Green Vehicle Guide is being redesigned to provide even more information on green vehicles -- including emissions, advanced technology vehicles, and alternative ...

308

Green Building - Kitchen  

Science.gov (United States)

... new appliances, or just looking for ways to green your everyday activities. Below, we first discuss the ... moisture and pest. Finally, we provide advice on green kitchen practices that you can implement today, at ...

309

Blue-green algae  

Science.gov (United States)

“Blue-green algae” describes a large and diverse group of simple, plant-like organisms found in salt water and some large fresh water lakes. Blue-green algae products are used for many conditions, but so ...

310

Sulfur capture in combination bark boilers  

Energy Technology Data Exchange (ETDEWEB)

A review of sulfur dioxide emission data for eight combination bark boilers in conjunction with the sulfur contents of the fuels reveals significant sulfur capture ranging from 10% to over 80% within the solid ash phase. Wood ash characteristics similar to activated carbon as well as the significant wood ash alkali oxide and carbonate fractions are believed responsible for the sulfur capture. Sulfur emissions from combination bark-fossil fuel firing are correlated to the sulfur input per ton of bark or wood residue fired.

Someshwar, A.V.; Jain, A.K. (National Council of the Paper Industry for Air and Stream Improvement, Gainesville, FL (United States))

1993-07-01

311

The Green Man  

Science.gov (United States)

The Jolly Green Giant. Robin Hood. The Bamberg Cathedral. Tales of King Arthur. Ecology. What do they have in common? What legends and ancient myths are shrouded in the tales of the Green Man? Most often perceived as an ancient Celtic symbol as the god of spring and summer, the Green Man disappears and returns year after year, century after…

Watson-Newlin, Karen

2010-01-01

312

The Green Agenda  

CERN Document Server

This business guide to Green IT was written to introduce, to a business audience, the opposing groups and the key climate change concepts, to provide an overview of a Green IT strategy and to set out a straightforward, bottom line-orientated Green IT action plan.

Calder, Alan

2009-01-01

313

In the Green  

Science.gov (United States)

Education officials used to debate whether they could afford to pursue green design and construction. Now the green movement has gained a foothold not just in education, but in society at large, and the prevailing attitude seems to have shifted. Can schools afford "not" to go green? As budgets are slashed repeatedly, education administrators must…

Kennedy, Mike

2011-01-01

314

What Is Green?  

Science.gov (United States)

Green is a question with varying answers and sometimes no answer at all. It is a question of location, resources, people, environment, and money. As green really has no end point, a teacher's goal should be to teach students to question and consider green. In this article, the author provides several useful metrics to help technology teachers…

Pokrandt, Rachel

2010-01-01

315

On the Origin of Sulfur  

CERN Multimedia

We present our work on the halo evolution of sulfur, based on observations of the S I lines around 9220 A for ten stars for which the S abundance was obtained previously from much weaker S I lines at 8694 A. We cannot confirm the rise and the high [S/Fe] abundances for low [Fe/H], as claimed in the literature from analysis of the 8694 A lines. The reasons for claims of an increase in [S/Fe] with decreasing [Fe/H] are probably twofold: uncertainties in the measurements of the weak 8694 A lines, and systematic errors in metallicity determinations from Fe I lines. The near-infrared sulfur triplet at 9212.9, 9228.1, and 9237.5 A are preferred for an abundance analysis of sulfur for metal-poor stars. Our work was presented in full by Ryde & Lambert (2004).

Ryde, N; Ryde, Nils; Lambert, David L.

2005-01-01

316

Monodisperse sulfuric acid aerosol generator  

Energy Technology Data Exchange (ETDEWEB)

A simple sulfuric acid aerosol generator which provides a reproducible aerosol of narrow size distribution has been developed. The method is based on the injection of heated SO/sub 3/ vapor in N/sub 2/ into a stream of humidified air. Particle diameter is adjustable from approximately 0.3 to 1.5 ..mu..m with a relative standard deviation of between 0.12 and 0.20. The generator is also capable of producing particles of <0.3 ..mu..m and >1.5 ..mu..m under special conditions. The sulfuric acid aerosol size distribution was obtained from optical particle counter data and verified using electron microscopy. The sulfuric acid concentration range of the generator is 0.3-3 mgm/sup -3/ depending upon the particle size produced.

Wall, S.

1982-01-01

317

Lactic Acid Bacteria  

Science.gov (United States)

This on-line exercise is focused on lactic acid bacteria, a group of related bacteria that produce lactic acid as a result of carbohydrate fermentation. It includes a protocol for the enrichment of lactic acid bacteria from enriched samples (like yogurt, sauerkraut, decaying plant matter, and tooth plaque). Three parameters are measured: growth, culture diversity, and pH. The exercise also includes instructions for the isolation of some of these bacteria by using the streak-plate method.

2010-03-01

318

Heat recovery from concentrated sulfuric acid  

Energy Technology Data Exchange (ETDEWEB)

This patent describes improvement in a process for the manufacture of sulfuric acid. It comprises: the catalytic oxidation of sulfur dioxide to sulfur trioxide, absorption of the sulfur trioxide in sulfuric acid, and cooling the sulfuric acid in a heat exchanger by transfer of heat to another fluid. The improvement comprises contacting a gas comprising sulfur trioxide with sulfuric acid in a primary absorption zone in a heat recovery tower, the sulfuric acid having a concentration between 98% and 101% and a temperature of at least 120{degrees} C.; contacting the gas exiting from the primary absorption zone with sulfuric acid in a secondary absorption zone positioned above the primary absorption zone in the heat recovery tower, the inlet temperature of the sulfuric acid to the secondary absorption zone being at least 10{degrees} C. cooler than the inlet temperature of the sulfuric acid to the primary absorption zone; and removing the heat of absorption in useful form from the sulfuric acid exiting the primary absorption zone by transfer of heat to another fluid, and thereby heating the another fluid to a temperature greater than 120{degrees} C.

McAlister, D.R.; Ziebold, S.A.

1991-02-26

319

XRF analysis for sulfur control  

Energy Technology Data Exchange (ETDEWEB)

The value of the modern X-ray spectrometer as a tool for flexible analysis over a wide range of multi-element determinations in the hydrocarbon industry is explained. Although the initial investment may be high in monetary terms, this is more than compensated for by the rapid and inexpensive sample preparation and analysis. Through the standard hardware and software interfaces, the process analytical X-ray system is easily integrated into the customer's quality and process control. The system is particularly useful for sulfur analysis and ISO 14596 describes the determination of sulfur in petroleum products by wavelength dispersive X-ray fluorescence spectrometry.

Uhlig, S.; Buehler, A. [Bruker Advanced X-ray Solutions GmbH (Germany)

2000-09-01

320

ALGAE-BACTERIA INTERACTION IN A LIGHT-DARK CYCLE (JOURNAL VERSION)  

Science.gov (United States)

Nutrient and population dynamics accompanying algae-bacteria interaction were observed in unialgal, 18-liter batch cultures during a light-dark cycle. The green alga Chlorella vulgaris, and the nitrogen fixing blue-green Anabaena flos-aquae were inoculated with an aquatic communi...

 
 
 
 
321

Promoting green engineering through green chemistry.  

UK PubMed Central (United Kingdom)

The decisions made by chemists in designing chemical products and processes directly impactthe options available to engineers. The physical and chemical properties of a material, for example, dictate the type of reactor that must be used in a given process. The task of the engineer is simplified when chemists design products and processes that reduce or eliminate the use and generation of hazardous substances. Green chemistry provides a foundation on which to build green engineering. This paper highlights green chemistry technologies that minimize the need for engineering safeguards in the areas of feedstocks, reagents, solvents, and syntheses.

Kirchhoff MM

2003-12-01

322

Bacteria are Everywhere!  

Science.gov (United States)

Through this activity, students are introduced to the concept of engineering biological organisms and studying their growth to be able to identify periods of fast and slow growth. Students learn that bacteria are found everywhere, including on the surface of our own hands. Students study three different conditions under which bacteria are found and compare the growth of the individual bacteria from each source. In addition to monitoring the quantity of bacteria from differ conditions, students also record the growth of bacteria over time, which is an excellent tool to study binary fission and the reproduction of unicellular organisms.

Applying Mechatronics to Promote Science (AMPS) GK-12 Program,

323

Silica Sulfuric Acid Promotes Aza-Michael Addition Reactions under Solvent-Free Condition as a Heterogeneous and Reusable Catalyst  

Directory of Open Access Journals (Sweden)

Full Text Available A highly efficient, inexpensive, recyclable, convenient, and green protocol for chemoselective aza-Michael addition reactions of amines/thiols to ?,?-unsaturated compounds using silica sulfuric acid (SSA or SiO2-SO3H) was developed. This method is simple, convenient and the title compounds are produced in good to excellent yields.

Yan Wang; Yan-Qin Yuan; Sheng-Rong Guo

2009-01-01

324

Silica Sulfuric Acid Promotes Aza-Michael Addition Reactions under Solvent-Free Condition as a Heterogeneous and Reusable Catalyst  

Digital Repository Infrastructure Vision for European Research (DRIVER)

A highly efficient, inexpensive, recyclable, convenient, and green protocol for chemoselective aza-Michael addition reactions of amines/thiols to ?,?-unsaturated compounds using silica sulfuric acid (SSA or SiO2-SO3H) was developed. This method is simple, convenient and the title compounds are produ...

Yan Wang; Yan-Qin Yuan; Sheng-Rong Guo

325

Two stage sorption of sulfur compounds  

International Nuclear Information System (INIS)

This patent describes a method for reducing the sulfur content of exhaust gases from the combustion of hydrocarbons. It comprises rapidly heating an alkali- or alkaline-earth-based sorbent powder to a temperature near its vaporization point so that the sorbent becomes an activated sorbent comprising part vapor and part liquid; injecting the activated sorbent into a sulfur-containing gas stream so as to form sulfur-containing sorbent; and quenching and collecting the sulfur-containing sorbent.

1991-05-08

326

Biodegradation of thiodiglycol, a hydrolyzate of the chemical weapon Yperite, by benzothiophene-desulfurizing bacteria.  

UK PubMed Central (United Kingdom)

Microbial degradation of thiodiglycol (bis(2-hydroxyethyl)sulfide, TDG) with petroleum-desulfurizing soil bacteria was examined. Among the bacteria tested, several strains belonging to the genera Rhodococcus and Gordonia grew on TDG as the sole sulfur source. The selected strain Rhodococcus sp. strain T09, which was re-identified as R. jostii, showed TDG degradation activity only when grown in the presence of TDG as the sole sulfur source. Repeat batch degradation of TDG by using strain T09 could be continued for over 50h, with a slight loss of activity.

El Bassi L; Shinzato N; Namihira T; Oku H; Matsui T

2009-08-01

327

Biodegradation of thiodiglycol, a hydrolyzate of the chemical weapon Yperite, by benzothiophene-desulfurizing bacteria.  

Science.gov (United States)

Microbial degradation of thiodiglycol (bis(2-hydroxyethyl)sulfide, TDG) with petroleum-desulfurizing soil bacteria was examined. Among the bacteria tested, several strains belonging to the genera Rhodococcus and Gordonia grew on TDG as the sole sulfur source. The selected strain Rhodococcus sp. strain T09, which was re-identified as R. jostii, showed TDG degradation activity only when grown in the presence of TDG as the sole sulfur source. Repeat batch degradation of TDG by using strain T09 could be continued for over 50h, with a slight loss of activity. PMID:19179003

El Bassi, Leila; Shinzato, Naoya; Namihira, Tomoyuki; Oku, Hirosuke; Matsui, Toru

2008-12-30

328

A study on the selection of indigenous leaching-bacteria for effective bioleaching  

Science.gov (United States)

Bioleaching technology, which is based on the ability of microorganisms to transform solid compounds into soluble and extractable valuable elements that can be recovered, has been rapidly developed in recent decades for its advantages, which include mild reaction condition, low energy consumption, simple process, low environmental impact and being suitable for low grade mine tailings and residues. The bacteria activities (survival, adaptation of toxically environments etc.) in the bioleaching technology play a key role in the solubilization of metals. The purpose of this study was to selection of optimal leaching-bacteria through changed pH and redox potential on bio-oxidation in batch experiments for successful bioleaching technology. Twenty three indigenous bacteria used throughout this study, leaching-bacteria were obtained from various geochemical conditions; bacteria inhabitation type (acid mine drainage, mine wastes leachate and sulfur hot springs) and base-metal type (sulfur, sulfide, iron and coal). Bio-oxidation experiment result was showed that 9 cycles (1 cycle - 28days) after the leaching-bacteria were inoculated to a leaching medium, pH was observed decreasing and redox potential increased. In the bacteria inhabitation type, bio-oxidation of sulfur hot springs bacteria was greater than other types (acid mine drainage and mine wastes leachate). In addition, bio-oxidation on base-metal type was appeared sulfur was greater than other types (sulfide, iron and coal). This study informs basic knowledge when bacteria apply to eco-/economic resources utilization studies including the biomining and the recycling of mine waste system.

Oh, S. J.; Cho, K. H.; Kim, B. J.; Choi, N. C.; Park, C. Y.

2012-04-01

329

Sulfur removal from coal through multiphase media containing biocatalysts  

Energy Technology Data Exchange (ETDEWEB)

A novel bioprocess using micelle biocatalysts was developed to minimize several disadvantages of conventional microbial coal desulfurization processes. The multiphase biocatalysis process consists of an organic medium (mineral oil or a mixture with n-heptane), a surfactant and an aqueous phase containing {ital Thiobacillus ferroxidans} organisms or their cell-free enzyme extracts. Water-in-oil emulsion and reverse micelle processes have been successful for removing sulfur from bituminous coal. The preliminary results indicated that, in the case of water-in-oil emulsion, the process that used the cell-free enzyme extracts of {ital T.ferroxidans} showed higher sulfur reduction than that containing whole cells, and reverse micelles were more effective than water-in-oil emulsion. With a high concentration of bacteria, more than 50% total sulfur removal was achieved through the reverse micelle system. These results indicate that multiphase biocatalysis may have a significant potential for developing biotechnical coal desulfurization processes. 22 refs., 4 figs., 1 tab.

Lee, K.-I.; Yen, T.F. (University of Southern California, Los Angeles, CA (USA). Dept. of Civil and Environmental Engineering)

1990-01-01

330

Two stage sorption of sulfur compounds  

Energy Technology Data Exchange (ETDEWEB)

A two stage method for reducing the sulfur content of exhaust gases is disclosed. Alkali- or alkaline-earth-based sorbent is totally or partially vaporized and introduced into a sulfur-containing gas stream. The activated sorbent can be introduced in the reaction zone or the exhaust gases of a combustor or a gasifier. High efficiencies of sulfur removal can be achieved.

Moore, William E. (Manassas, VA)

1992-01-01

331

Two stage sorption of sulfur compounds  

Energy Technology Data Exchange (ETDEWEB)

A two stage method for reducing the sulfur content of exhaust gases is disclosed. Alkali- or alkaline-earth-based sorbent is totally or partially vaporized 10 and introduced into a sulfur-containing gas stream. The activated sorbent can be introduced in the reaction zone or the exhaust gases of a combustor or a gasifier. High efficiencies of sulfur removal can be achieved.

Moore, W.E.

1991-12-31

332

Genetic engineering of sulfur-degrading Sulfolobus  

Energy Technology Data Exchange (ETDEWEB)

The objectives of the proposed research is to first establish a plasmid-mediated genetic transformation system for the sulfur degrading Sulfolobus, and then to clone and overexpress the genes encoding the organic-sulfur-degrading enzymes from Sulfolobus- as well as from other microorganisms, to develop a Sulfolobus-based microbial process for the removal of both organic and inorganic sulfur from coal.

Ho, N.W.Y.

1991-01-01

333

Immunobiological Consequences of Sulfur Mustard Contamination  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Sulfur mustard has been employed in chemical warfare in certain regions including Iran. The short and long term biological effects of sulfur mustard contamination have been studied in both basic and clinical aspects. Sulfur mustard has been shown to induce a vast array of pathological effects in aff...

Zuhair Mohammad Hassan; Massoumeh Ebtekar; Mostafa Ghanei; Mohammad Taghikhani; Mohammad Reza Noori Daloii; Tooba Ghazanfari

334

Reduction of sulfur dioxide with recycled coal  

Energy Technology Data Exchange (ETDEWEB)

A process is disclosed for removing sulfur dioxide from an off-gas and converting it to elemental sulfur. Steam is introduced into a sulfur dioxide-containing off-gas and the composite is passed through a reactor containing a mixture of fresh and recycled coal.

Dalton, S.M.; Gutterman, C.; Steiner, P.

1982-05-04

335

Seal for sodium sulfur battery  

Energy Technology Data Exchange (ETDEWEB)

This invention is directed to a seal for a sodium sulfur battery in which the sealing is accomplished by a radial compression seal made on a ceramic component of the battery which separates an anode compartment from a cathode compartment of the battery.

Topouzian, Armenag (Birmingham, MI); Minck, Robert W. (Lathrup Village, MI); Williams, William J. (Northville, MI)

1980-01-01

336

Avoid problems in sulfur units  

Energy Technology Data Exchange (ETDEWEB)

This paper presents design, equipment selection and operating practices which will help ensure trouble-free sulfur unit operation. General considerations are followed by a detailed discussion of the following topics: problems in defining the basis design; problems in equipment selection; and operating problems.

Tran, J.C.

1982-01-01

337

Biochemistry of dissimilatory sulfur oxidation  

Energy Technology Data Exchange (ETDEWEB)

Our goals of this research are to define the substrate oxidation pathways, the electron transport mechanisms, and the modes of energy conservation employed during the dissimilatory oxidation of sulfur by thiobacilli. We have purified APS reductase to electrophoratic homogeneity from cell-free extracts of Thiobacillus denitrificans. Sufficient protein is available to initiate the production of polyclonal antibodies and to perform the kinetic experiments.

Blake, R. II.

1992-01-01

338

SULFUR DIOXIDE SOURCES IN AK  

Science.gov (United States)

This map shows industrial plants which emit 100 tons/year or more of sulfur dioxide (SO2) in Alaska. The SO2 sources are plotted on a background map of cities and county boundaries. Data Sources: SO2 Sites: U.S. EPA AIRS System, County Outlines: 1990 Census Tiger Line Files 1:1...

339

Sulfur hexafluoride as a surrogate  

Energy Technology Data Exchange (ETDEWEB)

A viable chemical surrogate for monitoring the effectiveness of hazardous waste incinerators must include high thermal stability and low toxicity among its characteristics. The relationship between sulfur hexafluoride (SF6) and hazardous constituent thermal stability for a mixture of chlorinated hydrocarbons indicates that SF6 has the potential to satisfy the basic requirements of a chemical surrogate for hazardous waste incineration.

Taylor, P.H.; Chadbourne, J.F.

1987-06-01

340

Stoichiometric modeling of oxidation of reduced inorganic sulfur compounds (Riscs) in Acidithiobacillus thiooxidans.  

UK PubMed Central (United Kingdom)

The prokaryotic oxidation of reduced inorganic sulfur compounds (RISCs) is a topic of utmost importance from a biogeochemical and industrial perspective. Despite sulfur oxidizing bacterial activity is largely known, no quantitative approaches to biological RISCs oxidation have been made, gathering all the complex abiotic and enzymatic stoichiometry involved. Even though in the case of neutrophilic bacteria such as Paracoccus and Beggiatoa species the RISCs oxidation systems are well described, there is a lack of knowledge for acidophilic microorganisms. Here, we present the first experimentally validated stoichiometric model able to assess RISCs oxidation quantitatively in Acidithiobacillus thiooxidans (strain DSM 17318), the archetype of the sulfur oxidizing acidophilic chemolithoautotrophs. This model was built based on literature and genomic analysis, considering a widespread mix of formerly proposed RISCs oxidation models combined and evaluated experimentally. Thiosulfate partial oxidation by the Sox system (SoxABXYZ) was placed as central step of sulfur oxidation model, along with abiotic reactions. This model was coupled with a detailed stoichiometry of biomass production, providing accurate bacterial growth predictions. In silico deletion/inactivation highlights the role of sulfur dioxygenase as the main catalyzer and a moderate function of tetrathionate hydrolase in elemental sulfur catabolism, demonstrating that this model constitutes an advanced instrument for the optimization of At. thiooxidans biomass production with potential use in biohydrometallurgical and environmental applications.

Bobadilla Fazzini RA; Cortés MP; Padilla L; Maturana D; Budinich M; Maass A; Parada P

2013-08-01

 
 
 
 
341

Stoichiometric modeling of oxidation of reduced inorganic sulfur compounds (Riscs) in Acidithiobacillus thiooxidans.  

Science.gov (United States)

The prokaryotic oxidation of reduced inorganic sulfur compounds (RISCs) is a topic of utmost importance from a biogeochemical and industrial perspective. Despite sulfur oxidizing bacterial activity is largely known, no quantitative approaches to biological RISCs oxidation have been made, gathering all the complex abiotic and enzymatic stoichiometry involved. Even though in the case of neutrophilic bacteria such as Paracoccus and Beggiatoa species the RISCs oxidation systems are well described, there is a lack of knowledge for acidophilic microorganisms. Here, we present the first experimentally validated stoichiometric model able to assess RISCs oxidation quantitatively in Acidithiobacillus thiooxidans (strain DSM 17318), the archetype of the sulfur oxidizing acidophilic chemolithoautotrophs. This model was built based on literature and genomic analysis, considering a widespread mix of formerly proposed RISCs oxidation models combined and evaluated experimentally. Thiosulfate partial oxidation by the Sox system (SoxABXYZ) was placed as central step of sulfur oxidation model, along with abiotic reactions. This model was coupled with a detailed stoichiometry of biomass production, providing accurate bacterial growth predictions. In silico deletion/inactivation highlights the role of sulfur dioxygenase as the main catalyzer and a moderate function of tetrathionate hydrolase in elemental sulfur catabolism, demonstrating that this model constitutes an advanced instrument for the optimization of At. thiooxidans biomass production with potential use in biohydrometallurgical and environmental applications. PMID:23436458

Bobadilla Fazzini, Roberto A; Cortés, Maria Paz; Padilla, Leandro; Maturana, Daniel; Budinich, Marko; Maass, Alejandro; Parada, Pilar

2013-03-26

342

Density functional Green`s Function Theory  

Energy Technology Data Exchange (ETDEWEB)

Density Functional Theory is designed to treat the interacting electron system in the presence of an external potential which makes the density of the electrons inhomogeneous. The Green`s function method provides a way to construct the exact energy functionals, especially the exchange-correlation potential and systematic approximations for numerical evaluation. I shall discuss the philosophy of this approach versus others and give a cursory review of the applications to insulators and semiconductors, to interfaces, and to strongly-correlated metals.

Sham, L.J. [Univ. of California San Diego, La Jolla, CA (United States)

1996-12-31

343

Crystal structure of the electron carrier domain of the reaction center cytochrome c(z) subunit from green photosynthetic bacterium Chlorobium tepidum.  

UK PubMed Central (United Kingdom)

In green sulfur photosynthetic bacteria, the cytochrome c(z) (cyt c(z)) subunit in the reaction center complex mediates electron transfer mainly from menaquinol/cytochrome c oxidoreductase to the special pair (P840) of the reaction center. The cyt c(z) subunit consists of an N-terminal transmembrane domain and a C-terminal soluble domain that binds a single heme group. The periplasmic soluble domain has been proposed to be highly mobile and to fluctuate between oxidoreductase and P840 during photosynthetic electron transfer. We have determined the crystal structure of the oxidized form of the C-terminal functional domain of the cyt c(z) subunit (C-cyt c(z)) from thermophilic green sulfur bacterium Chlorobium tepidum at 1.3-A resolution. The overall fold of C-cyt c(z) consists of four alpha-helices and is similar to that of class I cytochrome c proteins despite the low similarity in their amino acid sequences. The N-terminal structure of C-cyt c(z) supports the swinging mechanism previously proposed in relation with electron transfer, and the surface properties provide useful information on possible interaction sites with its electron transfer partners. Several characteristic features are observed for the heme environment: These include orientation of the axial ligands with respect to the heme plane, surface-exposed area of the heme, positions of water molecules, and hydrogen-bond network involving heme propionate groups. These structural features are essential for elucidating the mechanism for regulating the redox state of cyt c(z).

Hirano Y; Higuchi M; Azai C; Oh-Oka H; Miki K; Wang ZY

2010-04-01

344

Go Green : greening real estate in Canada  

Energy Technology Data Exchange (ETDEWEB)

The Building Owners and Managers Association (BOMA) of Toronto promotes best practices in the building sector through education and effective management. Recent changes in public awareness and regulatory requirements have added a new significance to sustainability through energy efficiency in buildings. Go Green is BOMA's national environmental recognition and certification program. It was developed by industry for industry and constitutes a voluntary measure designed for existing or occupied buildings. Its purpose is to recognize those buildings where energy and environmental best practices have been implemented into operations, with the hope that a country-wide initiative may have a significant impact on the industry's approach to environmental issues. Go Green has several benefits. It provides building owners with tools to increase environmental stewardship; improve occupant's safety, health, comfort and productivity; improve a building's image; reduce energy consumption and operating costs; and reduce contribution to waste landfill sites. Go Green Plus enables owners to benchmark their building's performance through ongoing monitoring of emissions; energy use; water use; resources use; environmental management; and indoor environment. In an effort to demonstrate the Government of Canada's commitment to greening its operations, Public Works and Government Services Canada has adopted Go Green Plus as a standard for all federal government buildings. A recent survey has revealed that Go Green certified buildings use 11 per cent less energy; 18 per cent less water; and have 17 per cent better waste diversion. tabs., figs.

Proulx, W. [Building Owners and Managers Association of Toronto, Toronto, ON (Canada)

2007-07-01

345

Determination of total sulfur content via sulfur-specific chemiluminescence detection  

Energy Technology Data Exchange (ETDEWEB)

A specially designed system, based upon sulfur-specific chemiluminescence detection (SSCD), was developed to permit the determination of total sulfur content in a variety of samples. This type of detection system possesses several advantages such as excellent linearity and selectivity, low minimum detectable levels, and an equimolar response to various sulfur compounds. This paper will focus on the design and application of a sulfur-specific chemiluminescence detection system for use in determining total sulfur content in gasoline.

Kubala, S.W.; Campbell, D.N. [Fluid Data, Inc., Angleton, TX (United States); DiSanzo, F.P. [Paulsboro Research Lab., NJ (United States)

1995-12-31

346

Embedding Sulfur in MOF-Derived Microporous Carbon Polyhedrons for Lithium-Sulfur Batteries.  

UK PubMed Central (United Kingdom)

Microporous carbon polyhedrons (MPCPs) are derived from unique MOF polyhedrons, and used as a model microporous carbon host for sulfur in Li-S batteries. Systematic investigations have been carried out to reveal the effects of several important parameters, such as the sulfur loading temperature, sulfur content, and the electrolyte. The MPCP/sulfur composite with sulfur exclusively embedded in micropores exhibit stable cycling performance with high Coulombic efficiency in both DOL/DME and EC/DEC electrolytes.

Wu HB; Wei S; Zhang L; Xu R; Hng HH; Lou XW

2013-08-01

347

GreenLight Model 960.  

UK PubMed Central (United Kingdom)

The importance of food safety has resulted in a demand for a more rapid, high-throughput method for total viable count (TVC). The industry standard for TVC determination (ISO 4833:2003) is widely used but presents users with some drawbacks. The method is materials- and labor-intensive, requiring multiple agar plates per sample. More importantly, the method is slow, with 72 h typically required for a definitive result. Luxcel Biosciences has developed the GreenLight Model 960, a microtiter plate-based assay providing a rapid high-throughput method of aerobic bacterial load assessment through analysis of microbial oxygen consumption. Results are generated in 1-12 h, depending on microbial load. The mix and measure procedure allows rapid detection of microbial oxygen consumption and equates oxygen consumption to microbial load (CFU/g), providing a simple, sensitive means of assessing the microbial contamination levels in foods (1). As bacteria in the test sample grow and respire, they deplete O2, which is detected as an increase in the GreenLight probe signal above the baseline level (2). The time required to reach this increase in signal can be used to calculate the CFU/g of the original sample, based on a predetermined calibration. The higher the initial microbial load, the earlier this threshold is reached (1).

Fernandes R; Carey C; Hynes J; Papkovsky D

2013-03-01

348

Isolation of a Bacterial Inhibitor from Green Olives1  

Digital Repository Infrastructure Vision for European Research (DRIVER)

A compound inhibitory to lactic acid bacteria was isolated from green Manzanillo olives. The inhibitor is a phenolic compound, is devoid of acid-hydrolyzable reducing sugar, and has a bitter taste. Freezing the olives prior to extraction caused chemical changes which greatly increased the level of t...

Fleming, H. P.; Walter, W. M.; Etchells, J. L.

349

Culturable airborne bacteria in outdoor poultry-slaughtering facility.  

UK PubMed Central (United Kingdom)

Airborne bacteria are important biological components of the aerosols and have a close relationship with human health as they can have adverse effects through infection and toxicity; higher concentrations can result in various microbial diseases. Moreover, they have a great influence on air quality in Beijing. In this study, a systematic survey on culturable airborne bacteria was carried out for 1 year at a slaughtering plant in Beijing. Bacterial samples were collected with FA-1 sampler for 3 min, three times each day, for three consecutive days of each month from three sampling sites using BIOLOG identification technology. Results showed that Gram-positive bacteria contributed 80%-85% and were much more prevalent than Gram-negative bacteria. Amongst 47 genera of bacteria, including 31 Gram-positive bacteria and 16 Gram-negative bacteria, Micrococcus, Staphylococcus, Bacillus, Corynebacterium, and Pseudomonas were dominant, and Micrococcus, which contributed 20%-30%, was the most dominant genus. The concentration of airborne bacteria was significantly higher in shed used to stay chicken waiting for slaughtering (SSC) and entrances to personnel and transport vehicles with products (EPV) than in green belt (GB). During the year, bacterial concentrations in summer and autumn were much higher than in winter and spring in SSC and EPV, and there were no significant variations in bacterial concentrations in GB. In different periods, a lower concentration of airborne bacteria was found at 13:00.

Liang R; Xiao P; She R; Han S; Chang L; Zheng L

2013-01-01

350

INDUSTRIAL PROCESS PROFILES FOR ENVIRONMENTAL USE: CHAPTER 23. SULFUR, SULFUR OXIDES AND SULFURIC ACID  

Science.gov (United States)

The catalog of Industrial Process Profiles for Environmental Use was developed as an aid in defining the environmental impacts of industrial activity in the United States. Entries for each industry are in consistent format and form separate chapters of the study. The sulfur indus...

351

New sulfur concrete technology -- production and properties  

Energy Technology Data Exchange (ETDEWEB)

Sulfur concretes, which use a sulfur polymer as cement, are manufactured by hot mixing. Since sulfur is a by-product of the petrochemical industry, it is relatively inexpensive and easy to obtain. Also, sulfur concrete represents a reduction in carbon dioxide emissions, hence it is an environmentally acceptable product. This paper focuses on the formulation of different laboratory blends in order to determine optimal proportioning methods to obtain concretes with good mechanical properties and high durability. In field tests conducted in the Montreal area, compressive strengths of more than 50 MPa were obtained. Freeze-thaw properties of sulfur concretes were also found to be satisfactory. 5 refs., 4 tabs., 3 photos.

Gendreau, M.; Pigeon, M. [Service d`expertise en materiaux, Quebec City, PQ (Canada); Zmigrodzki, S. [Sulfur Polymer Development Corporation, PQ (Canada)

1998-12-31

352

Darwin y las bacterias Darwin and bacteria  

Directory of Open Access Journals (Sweden)

Full Text Available Con motivo de cumplirse 200 años del natalicio de Darwin y 150 desde la publicación de El Origen de las Especies, se revisa su obra buscando alguna mención de las bacterias, a las cuales el gran naturalista parece, o bien no haber conocido, algo muy difícil en un momento en que causaban sensación en el mundo científico, o bien haber ignorado deliberadamente, porque no encontraba para ellas lugar en su teoría de la evolución. Las bacterias, por su parte, afectaron malamente su vida familiar, falleciendo uno de sus hijos de escarlatina y su hija favorita, Arme, de una tuberculosis agravada por el mismo mal que mató a su hermano. El propio Darwin, desde el regreso del Beagle afectado por una enfermedad crónica hasta ahora no dilucidada, podría haber sufrido de la enfermedad de Chagas, cuyo agente etiológico, si bien no es una bacteria, tiene un similar nivel en la escala evolutiva.As in 2009 the scientific world celebrates two hundreds years from the birthday of Charles Darwin and one hundred and fifty from the publication of The Origin of Species, an analysis of his complete work is performed, looking for any mention of bacteria. But it seems that the great naturahst never took knowledge about its existence, something rather improbable in a time when the discovery of bacteria shook the medical world, or he deliberately ignored them, not finding a place for such microscopic beings into his theory of evolution. But the bacteria badly affected his familiar life, killing scarlet fever one of his children and worsening to death the evolution of tuberculosis of his favourite Annie. Darwin himself could suffer the sickness of Chagas, whose etiological agent has a similar level to bacteria in the scale of evolution.

Walter Ledermann D

2009-01-01

353

Darwin y las bacterias/ Darwin and bacteria  

Scientific Electronic Library Online (English)

Full Text Available Abstract in spanish Con motivo de cumplirse 200 años del natalicio de Darwin y 150 desde la publicación de El Origen de las Especies, se revisa su obra buscando alguna mención de las bacterias, a las cuales el gran naturalista parece, o bien no haber conocido, algo muy difícil en un momento en que causaban sensación en el mundo científico, o bien haber ignorado deliberadamente, porque no encontraba para ellas lugar en su teoría de la evolución. Las bacterias, por su parte, afectaron (more) malamente su vida familiar, falleciendo uno de sus hijos de escarlatina y su hija favorita, Arme, de una tuberculosis agravada por el mismo mal que mató a su hermano. El propio Darwin, desde el regreso del Beagle afectado por una enfermedad crónica hasta ahora no dilucidada, podría haber sufrido de la enfermedad de Chagas, cuyo agente etiológico, si bien no es una bacteria, tiene un similar nivel en la escala evolutiva. Abstract in english As in 2009 the scientific world celebrates two hundreds years from the birthday of Charles Darwin and one hundred and fifty from the publication of The Origin of Species, an analysis of his complete work is performed, looking for any mention of bacteria. But it seems that the great naturahst never took knowledge about its existence, something rather improbable in a time when the discovery of bacteria shook the medical world, or he deliberately ignored them, not finding a (more) place for such microscopic beings into his theory of evolution. But the bacteria badly affected his familiar life, killing scarlet fever one of his children and worsening to death the evolution of tuberculosis of his favourite Annie. Darwin himself could suffer the sickness of Chagas, whose etiological agent has a similar level to bacteria in the scale of evolution.

Ledermann D, Walter

2009-02-01

354

Green Infrastructure Glossary  

Science.gov (United States)

Green Infrastructure:  An adaptable term used to describe an array of products, technologies, and practices that use natural systems - or engineered systems that mimic natural processes - to enhance overall environmental quality and provide utility services. As a general principal, Green Infrastructure techniques use soils and vegetation to infiltrate, evapotranspirate, and/or recycle stormwater runoff. When used as components of a stormwater management system, Green Infrastructure practices such as green roofs, porous pavement, rain gardens, and vegetated swales can produce a variety of environmental benefits. In addition to effectively retaining and infiltrating rainfall, these technologies can simultaneously help filter air pollutants, reduce energy demands, mitigate urban heat islands, and sequester carbon while also providing communities with aesthetic and natural resource benefits.   From Green Infrastructure Glossary  -  Search all glossaries for terms containing "green infrastructure"

2011-05-24

355

Comparative uptake of sulfur in sulfur dioxide and acid rain by corn (Zea mays L. )  

Energy Technology Data Exchange (ETDEWEB)

This study has compared and evaluated the absorption and accumulation of sulfur from the two major forms of sulfur pollution (sulfur dioxide and sulfur containing acid rain), by seedlings of corn (Zea mays L.). Plants were exposed to matched treatments containing equivalent ..mu..moles S/treatment in sulfur dioxide or simulated acid rain containing sulfuric acid. Pollution levels were chosen to represent low, medium and high ambient pollutant concentrations (0.13, 1.3 and 130.0 ..mu..moles S/treatment). The uptake and distribution of sulfur by plants was followed by using radioactively labelled sulfur (35-S) in both pollutants. Plants were exposed to the pollutants via a single injection of sulfur dioxide or by rainfall simulators with acid rain treatments. From the sulfur dioxide concentrations evaluated (0.67; 1.00; 2.60; 6.70; and 16 ppm), maximum absorption occurred at the highest concentration while sulfur was more efficiently absorbed at lower concentrations. Absorption of sulfur by plants exposed to acid rain (pH 5.4; 4.4; 3.4; and 2.6) was higher with high sulfur/low pH treatments. pH per se, was not responsible for increased sulfur absorption at low pH treatments. Of the total sulfur associated with the plant following exposure to sulfur dioxide and acid rain, 55% and 97%, respectively was not absorbed, and could be released after one minute of a foliar wash. At each equivalent concentration of sulfur, corn seedlings absorbed significantly greater amounts of sulfur from sulfur dioxide than from acid rain.

Simon, J.E.

1984-01-01

356

Improving green roofs and rail road greening systems using Bacillus subtilis and Lactobacillus ssp.  

Science.gov (United States)

Aim of the present study was the improvement of existing methods for green roof and rail road greening systems using soil borne bacteria. Bacillus subtilis and Lactobacillus ssp. alone and in combination with vinasse applied to different growing substrates were tested. The substrates were brick chips, textile mats, mineral wool mats, and a commercial available substrate for the Swedish company VegTech. All four substrates were tested along an artificial rail track on the experimental station at Humboldt University Berlin, and partly on an existing rail track in Munich, Germany. Plants selected for the experiments belong to the genus Sedum, which is relatively tolerant to dry conditions. Inoculation of plants with bacteria had no effect on plant growth parameters and on coverage of different mobile bedding systems with Sedum plants. There was no significant difference between the various treatments in Munich. In both experiments, the addition of vinasse alone improved plant growth. Plant growth was significantly different on all substrates, whereas brick chips and the commercial roof soil was the best substrate. Brick chips are a cheap substrate which can be used for rail track greening. The results indicate that the quality of the substrate is the most important factor for remediation and greening of rail tracks and roof tops. The rapid growth of plants can be influenced by the application of vinasse as additional nutrient solution (potash (K) source) or nutrient enriched substrate. PMID:17390783

Grüneberg, H; Oschmann, C; Dunya, S; Ulrichs, C

2006-01-01

357

Removal of sulfur from process streams  

International Nuclear Information System (INIS)

A process wherein water is added to a non-reactive gas stream, preferably a hydrogen or hydrogen-containing gas stream, sufficient to raise the water level thereof to from about 0.2 percent to about 50 percent, based on the total volume of the process gas stream, and the said moist gas stream is contacted, at elevated temperature, with a particulate mass of a sulfur-bearing metal alumina spinel characterized by the formula MAl2O4, wherein M is chromium, iron, cobalt, nickel, copper, cadmium, mercury, or zinc to desorb sulfur thereon. In the sulfur sorption cycle, due to the simultaneous adsorption of water and sulfur, the useful life of the metal alumina spinel for sulfur adsorption can be extended, and the sorbent made more easily regenerable after contact with a sulfur-bearing gas stream, notably sulfur-bearing wet hydrogen or wet hydrogen-rich gas streams.

1984-01-01

358

Multiple heteroatom containing sulfur compounds in coals  

Energy Technology Data Exchange (ETDEWEB)

Flash vacuum pyrolysis of a high sulfur coal has been combined with high resolution mass spectrometry information on aromatic sulfur compounds containing an additional heteroatom. Sulfur emission from coal utilization is a critical problem and in order to devise efficient methods for removing organic sulfur, it is important to know what types of molecules contain sulfur. A high sulfur Illinois No. 6 bituminous coal (Argonne Premium Coal Sample No. 3) was pyrolyzed on a platinum grid using a quartz probe inserted into a modified all glass heated inlet system, and the products characterized by High Resolution Mass Spectrometry (HRMS). A significant number of products were identified which contained both sulfur and an additional heteroatom. In some cases two additional heteroatoms were observed. These results are compared to those found in coal extracted and liquefaction products. 25 refs., 5 figs., 4 tabs.

Winans, R.E.; Neill, P.H.

1989-01-01

359

Investigation of energy gene expressions and community structures of free and attached acidophilic bacteria in chalcopyrite bioleaching.  

UK PubMed Central (United Kingdom)

In order to better understand the bioleaching mechanism, expression of genes involved in energy conservation and community structure of free and attached acidophilic bacteria in chalcopyrite bioleaching were investigated. Using quantitative real-time PCR, we studied the expression of genes involved in energy conservation in free and attached Acidithiobacillus ferrooxidans during bioleaching of chalcopyrite. Sulfur oxidation genes of attached A. ferrooxidans were up-regulated while ferrous iron oxidation genes were down-regulated compared with free A. ferrooxidans in the solution. The up-regulation may be induced by elemental sulfur on the mineral surface. This conclusion was supported by the results of HPLC analysis. Sulfur-oxidizing Acidithiobacillus thiooxidans and ferrous-oxidizing Leptospirillum ferrooxidans were the members of the mixed culture in chalcopyrite bioleaching. Study of the community structure of free and attached bacteria showed that A. thiooxidans dominated the attached bacteria while L. ferrooxidans dominated the free bacteria. With respect to available energy sources during bioleaching of chalcopyrite, sulfur-oxidizers tend to be on the mineral surfaces whereas ferrous iron-oxidizers tend to be suspended in the aqueous phase. Taken together, these results indicate that the main role of attached acidophilic bacteria was to oxidize elemental sulfur and dissolution of chalcopyrite involved chiefly an indirect bioleaching mechanism.

Zhu J; Jiao W; Li Q; Liu X; Qin W; Qiu G; Hu Y; Chai L

2012-12-01

360

Genomics of Probiotic Bacteria  

Science.gov (United States)

Probiotic bacteria from the Lactobacillus and Bifidobacterium species belong to the Firmicutes and the Actinobacteria phylum, respectively. Lactobacilli are members of the lactic acid bacteria (LAB) group, a broadly defined family of microorganisms that ferment various hexoses into primarily lactic acid. Lactobacilli are typically low G + C gram-positive species which are phylogenetically diverse, with over 100 species documented to date. Bifidobacteria are heterofermentative, high G + C content bacteria with about 30 species of bifidobacteria described to date.

O'Flaherty, Sarah; Goh, Yong Jun; Klaenhammer, Todd R.

 
 
 
 
361

Nitrogen and sulfur requirements for Clostridium thermocellum and Caldicellulosiruptor bescii on cellulosic substrates in minimal nutrient media.  

UK PubMed Central (United Kingdom)

Growth media for cellulolytic Clostridium thermocellum ATCC 27405 and Caldicellulosiruptor bescii bacteria usually contain excess nutrients that would increase costs for consolidated bioprocessing for biofuel production and create a waste stream with nitrogen, sulfur and phosphate. C. thermocellum was grown on crystalline cellulose with varying concentrations of nitrogen and sulfur compounds, and growth rate and ethanol production response curves were determined. Both bacteria assimilated sulfate in the presence of ascorbate reductant, increasing the ratio of oxidized to reduced fermentation products. From these results, a low ionic strength, defined minimal nutrient medium with decreased nitrogen, sulfur, phosphate and vitamin supplements was developed for the fermentation of cellobiose, cellulose and acid-pretreated Populus. Carbon and electron balance calculations indicate the unidentified residual fermentation products must include highly reduced molecules. Both bacterial populations were maintained in co-cultures with substrates containing cellulose and xylan in defined medium with sulfate and basal vitamin supplements.

Kridelbaugh DM; Nelson J; Engle NL; Tschaplinski TJ; Graham DE

2013-02-01

362

Nitrogen and sulfur requirements for Clostridium thermocellum and Caldicellulosiruptor bescii on cellulosic substrates in minimal nutrient media.  

Science.gov (United States)

Growth media for cellulolytic Clostridium thermocellum ATCC 27405 and Caldicellulosiruptor bescii bacteria usually contain excess nutrients that would increase costs for consolidated bioprocessing for biofuel production and create a waste stream with nitrogen, sulfur and phosphate. C. thermocellum was grown on crystalline cellulose with varying concentrations of nitrogen and sulfur compounds, and growth rate and ethanol production response curves were determined. Both bacteria assimilated sulfate in the presence of ascorbate reductant, increasing the ratio of oxidized to reduced fermentation products. From these results, a low ionic strength, defined minimal nutrient medium with decreased nitrogen, sulfur, phosphate and vitamin supplements was developed for the fermentation of cellobiose, cellulose and acid-pretreated Populus. Carbon and electron balance calculations indicate the unidentified residual fermentation products must include highly reduced molecules. Both bacterial populations were maintained in co-cultures with substrates containing cellulose and xylan in defined medium with sulfate and basal vitamin supplements. PMID:23306120

Kridelbaugh, Donna M; Nelson, Joshua; Engle, Nancy L; Tschaplinski, Timothy J; Graham, David E

2012-12-27

363

Nitrogen and Sulfur Requirements for Clostridium thermocellum and Caldicellulosiruptor bescii on Cellulosic Substrates in Minimal Nutrient Media  

Energy Technology Data Exchange (ETDEWEB)

Growth media for cellulolytic Clostridium thermocellum and Caldicellulosiruptor bescii bacteria usually contain excess nutrients that would increase costs for consolidated bioprocessing for biofuel production and create a waste stream with nitrogen, sulfur and phosphate. C. thermocellum was grown on crystalline cellulose with varying concentrations of nitrogen and sulfur compounds, and growth rate and alcohol production response curves were determined. Both bacteria assimilated sulfate in the presence of ascorbate reductant, increasing the ratio of oxidized to reduced fermentation products. From these results, a low ionic strength, defined minimal nutrient medium with decreased nitrogen, sulfur, phosphate and vitamin supplements was developed for the fermentation of cellobiose, cellulose and acid-pretreated Populus. Carbon and electron balance calculations indicate the unidentified residual fermentation products must include highly reduced molecules. Both bacterial populations were maintained in co-cultures with substrates containing xylan or hemicellulose in defined medium with sulfate and basal vitamin supplements.

Kridelbaugh, Donna M [ORNL; Nelson, Josh C [ORNL; Engle, Nancy L [ORNL; Tschaplinski, Timothy J [ORNL; Graham, David E [ORNL

2013-01-01

364

Green gadgets for dummies  

CERN Document Server

Save some green by going green with these environmentally friendly gadgets! With concern for the future of our environment growing stronger and more serious every day, there has never been a better time to take a new approach to some of the most popular gizmos and gadgets on the market and learn how you can convernt to electronics that have minimal environmental impact. Green gadgets encompass everything from iPods to energy-efficient home entertainment devices to solar laptop chargers and crank-powered gizmos. This helpful resource explains how to research green gadgets, make a smart purc

Hutsko, Joe

2009-01-01

365

Bacteria-Antagonists  

International Science & Technology Center (ISTC)

Development of Biological Control Agents Through Use of Recombinant Antagonistic Bacteria Possessing Variable Mechanisms of Antagonisms, High Colonizing Capacity and Marker Traits for their Monitoring in Nature

366

Introduction to Bacteria  

Science.gov (United States)

This science site has students research how bacteria move, where they live, and how they reproduce; learn how bacteria can be helpful or harmful; and create a design illustrating what they have learned about bacteria. Included in the lesson plan are the objectives, needed materials and Web sites, procedures, discussion questions, evaluation, extensions, suggested reading, and vocabulary. Teachers can link to Teaching Tools to create custom worksheets, puzzles, and quizzes. A printable version of the lesson plan can be downloaded. The video Bacteria, Viruses and Allergies can be purchased and comprehension questions and answers can be downloaded.

Discoveryschool.com; Fenichel, Marilyn

2007-12-12

367

Utilizing the green alga Chlamydomonas reinhardtii for microbial electricity generation: a living solar cell  

Energy Technology Data Exchange (ETDEWEB)

By employing living cells of the green alga Chlamydomonas reinhardtii, we demonstrate the possibility of direct electricity generation from microbial photosynthetic activity. The presented concept is based on an in situ oxidative depletion of hydrogen, photosynthetically produced by C. reinhardtii under sulfur-deprived conditions, by polymer-coated electrocatalytic electrodes. (orig.)

Rosenbaum, M.; Schroeder, U.; Scholz, F. [Greifswald Univ. (Germany). Inst. fuer Chemie und Biochemie

2005-10-01

368

Potentials and Green`s functions in transversely isotropic piezoelectricity  

Energy Technology Data Exchange (ETDEWEB)

We present closed-form expressions for the infinite-body Green`s functions for a transversely isotropic piezoelectric medium. We obtain the Green`s functions using a formulation where the three elastic displacement components and the electric potential are derivable from two potential functions. The potentials and Green`s functions can be easily used in the solution of numerous problems in transversely isotropic piezoelectricity.

Dunn, M.L.; Wienecke, H.A. [Univ. of Colorado, Boulder, CO (United States)

1995-12-31

369

[Effect of dissolved oxygen on microbial community in simultaneous removal of carbon, nitrogen and sulfur process].  

UK PubMed Central (United Kingdom)

In order to investigate the effect of dissolved oxygen (DO) on microbial community in simultaneous removal of carbon, nitrogen and sulfur process and reveal the mechanism of high elemental sulfur conversion rate under aerobic condition, GeoChip was employed to characterize the structure of microbial community. The results indicated that the microbial community structure significantly changed with different aerobic conditions (P < 0.001). Diversity indices of microbial community increased at relatively high DO level. However, denitrifiers were greatly inhibited at this level due to the high sensitivity to DO. There was no significant change detected in the abundance of sulfate-reducing bacteria (SRB) with the changing DO. The relative abundance of sox gene showed significant difference between aeration rate of 20 mL x min(-1) and aeration rate of 0 mL x min(-1), which might suggest that the activity of sulfur-oxidizing bacteria (SOB) was obviously improved by DO. Moreover, cluster analysis of sox gene confirmed this suggestion, with higher signal intensity found in numbers of probes derived from SOB under such aerobic conditions. Overall, the results revealed a positive effect of micro-aerobic conditions on the simultaneous removal of carbon, nitrogen and sulfur process.

Yu H; Chen C; Zhang L; Wang AJ

2013-06-01

370

Green tea: Health benefits.  

UK PubMed Central (United Kingdom)

The plant Camellia sinensis yields a variety of white, green and black tea. Tea is one of the most widely consumed beverages in the world, next only to water for enjoyment and health. In general, green tea has been found to be superior to black tea in terms of health benefits. The major components of interest are the polyphenols which are responsible for the antioxidant and other health benefits of green tea. The major polyphenols in green tea are flavonoids. The four major flavonoids in green tea are the catechins, epicatechin (EC), epigallocatechin (EGC), epicatechin gallate (ECG) and epigallocatechin gallate (EGCG). Epigallocatechin gallate is viewed as the most significant active component. The processes used in the manufacture of black tea are known to decrease levels of the monometric catechins to a much greater extent than the less severe conditions applied to other teas. Much research is available depicting the health benefits of green tea for a wide variety of implications, including different types of cancer, heart disease, liver disease, etc. There is also a wide range of uses for green tea in diabetes, exercise enhancement, inflammatory bowel disease, skin disorders, hair loss, weight loss and iron overload. This paper will review the major health benefits of green tea, focusing on the catechins.

Sinija VR; Mishra HN

2008-03-01

371

The Green Office  

CERN Document Server

Any Green IT strategy should include a Green Office component, that tackles power consumption and paper usage in the office/work environment as well as in the data centre. While the most significant savings are made where the bulk of data processing is carried out (ie the data centre), savings can also be achieved in terms of workstations and related office IT equipment.

Calder, Alan

2009-01-01

372

Green Chemistry and Education.  

Science.gov (United States)

Many students today are profoundly interested in the sustainability of their world. Introduces Green Chemistry and its principles with teaching materials. Green Chemistry is the use of chemistry for pollution prevention and the design of chemical products and processes that are environmentally benign. (ASK)

Hjeresen, Dennis L.; Schutt, David L.; Boese, Janet M.

2000-01-01

373

Wall greening ceramic tiles  

UK PubMed Central (United Kingdom)

The invention discloses a wall greening tile, belonging to a building material, which has simple structure, easy to manufacture, and has functions of protecting wall, bearing weight, increasing green area, purifying air, preserving water resources, lowering indoor temperature, adjusting surrounding humidity, eliminating city noises and improving city ecological environment. And it is applied to outer walls of buildings in various big cities.

ZHAN JINGWEN

374

10 Paths to Green  

Science.gov (United States)

Some institutions may feel comfortable with a few baby steps into the green world, while others may be ready to commit totally to environmental consciousness. Here, the author discusses 10 areas in which educators and administrators can beef up their green portfolio. These areas are in: alternative fuel, bikes/walking, water, education tools,…

Kennedy, Mike

2008-01-01

375

Green by Default  

DEFF Research Database (Denmark)

The article offers information on the two sources of energy including green energy and gray energy. It discusses several facts which includes lower levels of greenhouse gases and conventional pollutants, relationship between economic incentives and underlying preferences and potential effects of green default rules..

Sunstein, Cass R.; Reisch, Lucia

2013-01-01

376

How bacteria choose phosphate.  

UK PubMed Central (United Kingdom)

Discriminating against arsenate: Determination of the structure of periplasmic phosphate binding proteins at very high resolution provides the basis for understanding the high discrimination of bacteria against arsenate. The results complete our insight into earlier erroneous conclusions on the ability of certain bacteria to use arsenate instead of phosphate.

Goody RS

2013-02-01

377

Green energy; Groenn energi  

Energy Technology Data Exchange (ETDEWEB)

The Norwegian Ministry of Petroleum and Energy is considering a compulsory, green certificate market for renewable energy. This market will stimulate the development of renewable energy sources. In some ways, green certificates is subsidising and instigating the development of energy sources that would otherwise be unprofitable. A green certificate proves that a certain quantity of energy, which is usually electricity, has been produced, and that it is based on renewable energy sources. In the EU there are two driving forces behind the concentration on green energy: the liberalization of the European energy market, and EU's quantitative emission restrictions. However, there is a difference of opinion about the usefulness of a green certificate market if the goal is to increase the production of renewable energy.

Haaland, Leif

2004-07-01

378

Green tea in dermatology.  

UK PubMed Central (United Kingdom)

The purpose of this brief review is to summarize all in vitro, in vivo, and controlled clinical trials on green tea preparations and their uses in dermatology. An extensive literature search was carried out to identify in vivo and in vitro studies as well as clinical trials. Twenty studies were assessed and the results suggest that oral administration of green tea can be effective in the scavenging of free radicals, cancer prevention, hair loss, and skin aging plus protection against the adverse effects associated with psoralen-UV-A therapy. Topical application of green tea extract should be potentially effective for atopic dermatitis, acne vulgaris, rosacea, androgenetic alopecia, hirsutism, keloids, genital warts, cutaneous leishmaniasis, and candidiosis. There are promising results with the use of green tea for several dermatologic conditions; however, the efficacy of oral and topical green tea has not always been confirmed.

Pazyar N; Feily A; Kazerouni A

2012-11-01

379

Biharmonic Green functions  

Directory of Open Access Journals (Sweden)

Full Text Available The harmonic Green and Neumann function and a particular Robin function are used to construct bi-harmonic Green, Neumann and particular Robin functions. Moreover hybrid bi-harmonic Green functions are given. They all are constructed via a convolution of the mentioned harmonic particular fundamental solutions. In case of the unit disc they are explicitly expressed. Besides these 9 bi-harmonic Green functions there is another bi-harmonic Green function in explicit form for the unit disc not defined by convolution. Related boundary value problems are not all well posed. In case they are, the unique solutions are given. For the other cases solvability conditions are determined and the unique solutions found. There are all together 12 Dirichlet kind boundary value problems for the inhomogeneous bi-harmonic equation treated. The investigation is restricted to the two dimensional case and complex notation is used.

Heinrich Begehr

2006-01-01

380

"Green Schools" in China  

Directory of Open Access Journals (Sweden)

Full Text Available In this paper you can see the history and the connotation of "Green Schools". Through an analysis of a case, the paper indicate that it has been formed some essential characters of "Green Schools" in China.In recent years the development of Chinese "Green Schools" was speedy, and gained some achievement. The paper recommend this, too.There are some problems and obstacles in the development. We must think much of this, and resolve it. There are some contrasts between some foreign countries and China about the characters of "Green Schools". There are some discussions and solved measures about the problems and obstacles of "Green Schools" in the 4th part.

Fang XIAO

2002-01-01

 
 
 
 
381

Sulfur Nanoparticles Synthesis and Characterization from H2S Gas, Using Novel Biodegradable Iron Chelates in W/O Microemulsion  

Directory of Open Access Journals (Sweden)

Full Text Available AbstractSulfur nanoparticles were synthesized from hazardous H2S gas using novel biodegradable iron chelates in w/o microemulsion system. Fe3+–malic acid chelate (0.05 M aqueous solution) was studied in w/o microemulsion containing cyclohexane, Triton X-100 andn-hexanol as oil phase, surfactant, co-surfactant, respectively, for catalytic oxidation of H2S gas at ambient conditions of temperature, pressure, and neutral pH. The structural features of sulfur nanoparticles have been characterized by X-ray diffraction (XRD), transmission electron microscope (TEM), energy dispersive spectroscopy (EDS), diffused reflectance infra-red Fourier transform technique, and BET surface area measurements. XRD analysis indicates the presence of ?-sulfur. TEM analysis shows that the morphology of sulfur nanoparticles synthesized in w/o microemulsion system is nearly uniform in size (average particle size 10 nm) and narrow particle size distribution (in range of 5–15 nm) as compared to that in aqueous surfactant systems. The EDS analysis indicated high purity of sulfur (>99%). Moreover, sulfur nanoparticles synthesized in w/o microemulsion system exhibit higher antimicrobial activity (against bacteria, yeast, and fungi) than that of colloidal sulfur.

Deshpande Aniruddha; Khomane Ramdas; Vaidya Bhalchandra; Joshi Renuka; Harle Arti; Kulkarni Bhaskar

2008-01-01

382

Green Informatics: ICT for Green and Sustainability  

Directory of Open Access Journals (Sweden)

Full Text Available Green Informatics constitute a new term in the science of information that describes the utilization of informatics in the interest of the natural environment and the natural resources regarding sustainability and sustainable development. Nowadays, ICT has introduced the convergence of e-services with broadband network infrastructure, wireless technologies and mobile devices. The revolution of ICTs introduction in daily average life has also resulted in the increase of GHG, since the ’’carbon footprint’’ is continually increasing. The dimensions of Green Informatics contribution are: the reduction of energy consumption, the rise of environmental awareness, the effective communication for environmental issues and the environmental monitoring and surveillance systems, as a means to protect and restore natural ecosystems potential. EU has reinforced the environmental sector with focus on high level of protection and improvement of the quality of environment through the enacting of strategies, initiatives and measures. Future EU strategy aims to a low carbon European society by 2050 and to green/sustainable development, ICTs can play a key role in the environmental protection and sustainability, however, green behavior is still critical.

Zacharoula S. Andreopoulou

2012-01-01

383

Removal of sulfur from process streams  

Energy Technology Data Exchange (ETDEWEB)

A process is claimed where a particulate mass of a metal alumina spinel, MAl/sub 2/O/sub 4/ where M is chromium, iron, cobalt, nickel, copper, cadmium or mercury, particularly zinc alumina spinel (ZnAl/sub 2/O/sub 4/), is contacted with a process stream which contains sulfur, sulfur compounds, and other contaminants. These are adsorbed onto said particulate mass of metal alumina spinel, and the process stream thereby denuded of said sulfur, sulfur compounds, and other contaminants. Thereafter, the sulfur, sulfur compounds, and other contaminants, are readily desorbed, or removed from said particulate mass of metal alumina spinel by contacting, and purging same with a relatively clean gas stream, suitably hydrogen, hydrogen-containing gas, or an inert gas, at elevated temperature.

Eberly, P.E.

1981-04-21

384

Coal beneficiation-sulfur removal using methanol  

Energy Technology Data Exchange (ETDEWEB)

The removal of sulfur from coal by methanol has been investigated in a 300 ml batch reactor. The Illinois IBC-108 coal used is highly beneficiated and contains mainly organic sulfur, the results are, therefore, also applicable to organic sulfur removal. Temperature, reaction time and the amount of methanol increased sulfur removal, while the amount of coal used decreased it. Coal pyrolysis was explored in both open and closed systems. The best results, a total sulfur removal of 86% (90% for organic) were obtained at 500{degrees}C, 60 - 90 min. reaction time and very small amounts of coal, with a weight loss of about 30%. An empirical correlation for total sulfur removal is presented.

Guanghui Wang [Wuhan Yejin Univ. of Science and Technology, Hubei (China); Trass, O. [Univ. of Toronto, Ontario (Canada)

1997-07-01

385

The nature of sulfur in petroleum cokes  

Energy Technology Data Exchange (ETDEWEB)

A radioactive indicator method is used to investigate the nature of sulfur detected in coking sediments, in industrial byproducts and in sintered cokes obtained from the sulfur byproduct of oil. It is demonstrated that the sulfide based compounds are unstable and are separated from the reaction mass as early as the coking process. The sulfur enters the coke only from the raw material components containing dibenzothiophene or a more aromatic thiophene fragment. During thermal processing up to 2000 degrees centigrade, the radioactive sulfur introduced into the coke by these components behaves precisely in the same manner as does sulfur detected by standard analytical methods, which confirms the thiophene nature of the sulfur in the coke.

Varfolomeyev, D.F.; Akhmetov, M.M.; Khayrutdinov, I.R.; Mukhametzyanova, R.M.

1984-01-01

386

New insights into metabolic properties of marine bacteria encoding proteorhodopsins.  

Directory of Open Access Journals (Sweden)

Full Text Available Proteorhodopsin phototrophy was recently discovered in oceanic surface waters. In an effort to characterize uncultured proteorhodopsin-exploiting bacteria, large-insert bacterial artificial chromosome (BAC) libraries from the Mediterranean Sea and Red Sea were analyzed. Fifty-five BACs carried diverse proteorhodopsin genes, and we confirmed the function of five. We calculate that proteorhodopsin-exploiting bacteria account for 13% of microorganisms in the photic zone. We further show that some proteorhodopsin-containing bacteria possess a retinal biosynthetic pathway and a reverse sulfite reductase operon, employed by prokaryotes oxidizing sulfur compounds. Thus, these novel phototrophs are an unexpectedly large and metabolically diverse component of the marine microbial surface water.

Sabehi Gazalah; Loy Alexander; Jung Kwang-Hwan; Partha Ranga; Spudich John L; Isaacson Tal; Hirschberg Joseph; Wagner Michael; Béjà Oded

2005-01-01

387

Microbial Sulfur Geochemistry in Mine Systems (Invited)  

Science.gov (United States)

Acid mine drainage (AMD), metal laden, acidic water, is the most pressing mining environmental issue on a global scale. While it is well recognized that the activity of autotrophic Fe and S bacteria amplify the oxidation of the sulfidic wastes, thereby generating acidity and leaching metals; the underlying microbial geochemistry is not well described. This talk will highlight results revealing the importance of microbial cooperation associated with a novel sulfur-metabolizing consortium enriched from mine waters. Results generated by an integrated approach, combining field characterization, geochemical experimentation, scanning transmission X-ray microscopy (STXM), and fluorescence in situ hybridization (FISH) [1]describing the underlying ecological drivers, the functionally relevant biogeochemical architecture of the consortial macrostructure as well as the identities of this environmental sulphur redox cycling consortium will be presented. The two common mine bacterial strains involved in this consortium, Acidithiobacillus ferroxidans and Acidiphilium sp., are specifically spatially segregated within a macrostructure (pod) of extracellular polymeric substance (EPS) that enables coupled sulphur oxidation and reduction reactions despite bulk, oxygenated conditions. Identical pod formation by type culture strains was induced and linked to ecological conditions. The proposed sulphur geochemistry associated with this bacterial consortium produces 40-90% less acid than expected based on abiotic AMD models, with implications for both AMD mitigation and AMD carbon flux modeling. We are currently investigating the implications of these sulphur-processing pods for metal dynamics in mine systems. These results demonstrate how microbes can orchestrate their geochemical environment to facilitate metabolism, and underscore the need to consider microbial interactions and ecology in constraining their geochemical impacts. [1] Norlund, Southam, Tyliszcczak, Hu, Karunakaran, Obst, Hitchcock &Warren (2009) Environmental Science & Technology 43, 8781-8786.

Warren, L. A.; Norlund, K. L.; Hitchcock, A.

2010-12-01

388

Topsoe`s Wet gas Sulfuric Acid (WSA) process: An alternative technology for recovering refinery sulfur  

Energy Technology Data Exchange (ETDEWEB)

The Topsoe Wet gas Sulfuric Acid (WSA) process is a catalytic process which produces concentrated sulfuric acid from refinery streams containing sulfur compounds such as H{sub 2}S (Claus plant feed), Claus plant tail gas, SO{sub 2} (FCC off-gas, power plants), and spent sulfuric acid (alkylation acid). The WSA process recovers up to 99.97% of the sulfur value in the stream as concentrated sulfuric acid (93--98.5 wt%). No solid waste products or waste water is produced and no chemicals are consumed in the process. The simple process layout provides low capital cost and attractive operating economy. Twenty four commercial WSA plants have been licensed. The WSA process is explained in detail and comparisons with alternative sulfur management technology are presented. Environmental regulations applying to SO{sub x} abatement and sulfuric acid production plants are explained in the context of WSA plant operation.

Ward, J.W. [Haldor Topsoe, Inc., Houston, TX (United States)

1995-09-01

389

Thiophenic Sulfur Compounds Released During Coal Pyrolysis.  

UK PubMed Central (United Kingdom)

Thiophenic sulfur compounds are released during coal gasification, carbonization, and combustion. Previous studies indicate that thiophenic sulfur compounds degrade very slowly in the environment, and are more carcinogenic than polycyclic aromatic hydrocarbons and nitrogenous compounds. Therefore, it is very important to study the principle of thiophenic sulfur compounds during coal conversion, in order to control their emission and promote clean coal utilization. To realize this goal and understand the formation mechanism of thiophenic sulfur compounds, this study focused on the release behavior of thiophenic sulfur compounds during coal pyrolysis, which is an important phase for all coal thermal conversion processes. The pyrolyzer (CDS-5250) and gas chromatography-mass spectrometry (Focus GC-DSQII) were used to analyze thiophenic sulfur compounds in situ. Several coals with different coal ranks and sulfur contents were chosen as experimental samples, and thiophenic sulfur compounds of the gas produced during pyrolysis under different temperatures and heating rates were investigated. Levels of benzothiophene and dibenzothiophene were obtained during pyrolysis at temperatures ranging from 200°C to 1300°C, and heating rates ranging from 6°C/ms to 14°C/ms and 6°C/s to 14°C/s. Moreover, the relationship between the total amount of benzothiophene and dibenzothiophene released during coal pyrolysis and the organic sulfur content in coal was also discussed. This study is beneficial for understanding the formation and control of thiophenic sulfur compounds, since it provides a series of significant results that show the impact that operation conditions and organic sulfur content in coal have on the amount and species of thiophenic sulfur compounds produced during coal pyrolysis.

Xing M; Kong J; Dong J; Jiao H; Li F

2013-06-01

390

Decomposition of zeolite by sulfuric acid  

International Nuclear Information System (INIS)

The given work studies the processing of aluminium containing ore-zeolite by sulfuric acid. Extraction dependence of zeolites useful components from temperature process period, concentration of sulfuric acid on zeolite particles is shown. As a result of the processing zeolite by sulfuric acid authors synthesized the aluminium sulphate and iron (which can be used as coagulants) and left compound can be used as absorbent (as it contains more than 50% of amorphous silicate) and as raw material for manufacture of liquid glass

2003-01-01

391

Process for the recovery of sulfuric acid  

Energy Technology Data Exchange (ETDEWEB)

The disclosure describes the recovery of sulfuric acid from industrial liquors containing the same. A selective liquid-liquid extraction of said liquors is carried out under conditions producing an organic phase containing the sulfuric acid and an aqueous phase eventually containing impurities. The organic phase is treated with a base, such as gaseous NH/sub 3/, in order to separate the sulfuric acid. This process is simple, non-polluting, and requires little energy.

Kougioumoutzakis, D.

1984-04-03

392

HYDROCARBON AND SULFUR SENSORS FOR SOFC SYSTEMS  

Energy Technology Data Exchange (ETDEWEB)

The following report summarizes work conducted during the Phase I program Hydrocarbon and Sulfur Sensors for SOFC Systems under contract No. DE-FC26-02NT41576. For the SOFC application, sensors are required to monitor hydrocarbons and sulfur in order to increase the operation life of SOFC components. This report discusses the development of two such sensors, one based on thick film approach for sulfur monitoring and the second galvanic based for hydrocarbon monitoring.

A.M. Azad; Chris Holt; Todd Lesousky; Scott Swartz

2003-11-01

393

Phylogenetic analysis on the soil bacteria distributed in karst forest  

Directory of Open Access Journals (Sweden)

Full Text Available Phylogenetic composition of bacterial community in soil of a karst forest was analyzed by culture-independent molecular approach. The bacterial 16S rRNA gene was amplified directly from soil DNA and cloned to generate a library. After screening the clone library by RFLP, 16S rRNA genes of representative clones were sequenced and the bacterial community was analyzed phylogenetically. The 16S rRNA gene inserts of 190 clones randomly selected were analyzed by RFLP and generated 126 different RFLP types. After sequencing, 126 non-chimeric sequences were obtained, generating 113 phylotypes. Phylogenetic analysis revealed that the bacteria distributed in soil of the karst forest included the members assigning into Proteobacteria, Acidobacteria, Planctomycetes, Chloroflexi (Green nonsulfur bacteria), Bacteroidetes, Verrucomicrobia, Nitrospirae, Actinobacteria (High G+C Gram-positive bacteria), Firmicutes (Low G+C Gram-positive bacteria) and candidate divisions (including the SPAM and GN08).

JunPei Zhou; Ying Huang; MingHe Mo

2009-01-01

394

Phylogenetic analysis on the soil bacteria distributed in karst forest  

Scientific Electronic Library Online (English)

Full Text Available Abstract in english Phylogenetic composition of bacterial community in soil of a karst forest was analyzed by culture-independent molecular approach. The bacterial 16S rRNA gene was amplified directly from soil DNA and cloned to generate a library. After screening the clone library by RFLP, 16S rRNA genes of representative clones were sequenced and the bacterial community was analyzed phylogenetically. The 16S rRNA gene inserts of 190 clones randomly selected were analyzed by RFLP and genera (more) ted 126 different RFLP types. After sequencing, 126 non-chimeric sequences were obtained, generating 113 phylotypes. Phylogenetic analysis revealed that the bacteria distributed in soil of the karst forest included the members assigning into Proteobacteria, Acidobacteria, Planctomycetes, Chloroflexi (Green nonsulfur bacteria), Bacteroidetes, Verrucomicrobia, Nitrospirae, Actinobacteria (High G+C Gram-positive bacteria), Firmicutes (Low G+C Gram-positive bacteria) and candidate divisions (including the SPAM and GN08).

Zhou, JunPei; Huang, Ying; Mo, MingHe

2009-12-01

395

Biotin synthase: insights into radical-mediated carbon-sulfur bond formation.  

Science.gov (United States)

The enzyme cofactor and essential vitamin biotin is biosynthesized in bacteria, fungi, and plants through a pathway that culminates with the addition of a sulfur atom to generate the five-membered thiophane ring. The immediate precursor, dethiobiotin, has methylene and methyl groups at the C6 and C9 positions, respectively, and formation of a thioether bridging these carbon atoms requires cleavage of unactivated CH bonds. Biotin synthase is an S-adenosyl-l-methionine (SAM or AdoMet) radical enzyme that catalyzes reduction of the AdoMet sulfonium to produce 5'-deoxyadenosyl radicals, high-energy carbon radicals that can directly abstract hydrogen atoms from dethiobiotin. The available experimental and structural data suggest that a [2Fe-2S](2+) cluster bound deep within biotin synthase provides a sulfur atom that is added to dethiobiotin in a stepwise reaction, first at the C9 position to generate 9-mercaptodethiobiotin, and then at the C6 position to close the thiophane ring. The formation of sulfur-containing biomolecules through a radical reaction involving an iron-sulfur cluster is an unprecedented reaction in biochemistry; however, recent enzyme discoveries suggest that radical sulfur insertion reactions may be a distinct subgroup within the burgeoning Radical SAM superfamily. This article is part of a Special Issue entitled: Radical SAM enzymes and Radical Enzymology. PMID:22326745

Fugate, Corey J; Jarrett, Joseph T

2012-01-28

396

Biotin synthase: insights into radical-mediated carbon-sulfur bond formation.  

UK PubMed Central (United Kingdom)

The enzyme cofactor and essential vitamin biotin is biosynthesized in bacteria, fungi, and plants through a pathway that culminates with the addition of a sulfur atom to generate the five-membered thiophane ring. The immediate precursor, dethiobiotin, has methylene and methyl groups at the C6 and C9 positions, respectively, and formation of a thioether bridging these carbon atoms requires cleavage of unactivated CH bonds. Biotin synthase is an S-adenosyl-l-methionine (SAM or AdoMet) radical enzyme that catalyzes reduction of the AdoMet sulfonium to produce 5'-deoxyadenosyl radicals, high-energy carbon radicals that can directly abstract hydrogen atoms from dethiobiotin. The available experimental and structural data suggest that a [2Fe-2S](2+) cluster bound deep within biotin synthase provides a sulfur atom that is added to dethiobiotin in a stepwise reaction, first at the C9 position to generate 9-mercaptodethiobiotin, and then at the C6 position to close the thiophane ring. The formation of sulfur-containing biomolecules through a radical reaction involving an iron-sulfur cluster is an unprecedented reaction in biochemistry; however, recent enzyme discoveries suggest that radical sulfur insertion reactions may be a distinct subgroup within the burgeoning Radical SAM superfamily. This article is part of a Special Issue entitled: Radical SAM enzymes and Radical Enzymology.

Fugate CJ; Jarrett JT

2012-11-01

397

Options for small-scale sulfur recovery  

Energy Technology Data Exchange (ETDEWEB)

With the issuance by the Alberta Energy Resources Conservation Board and Alberta Environment of their report entitled Sulphur Recovery Guidelines for Sour Gas Plants in Alberta in August of 1988, the requirement in Alberta to recover sulfur was broadened to a sulfur content of 1 ton/D or greater in the inlet gas to a new sour-gas treating plant. This paper reviews the processes in use for recovering sulfur from sour-natural-gas streams that have a total sulfur content of 5 ton/D or less. These processes are the modified Claus process, the recycle Selectox process, and the reduction/oxidation processes LO-CAT and SulFerox. While the modified Claus process is used in large sulfur-recovery plants, the other processes may be more economical for sulfur recovery on a small scale. A description of the sour-gas treating and sulfur-recovery processes is given, and a comparison of estimated capital and operating costs for typical sour-gas streams is provided. All of the above processes are in operation in North America. Operating experiences with these processes in Alberta are discussed. The quality of the end-product sulfur varies among these processes, and the options for sulfur disposal are reviewed.

Royan, T. [Tartan Engineering Corp. Ltd. (Canada); Wichert, E. [Gascan Resources Ltd., Calgary, Alberta (Canada)

1997-11-01

398

Improved sulfur removal processes evaluated for IGCC  

Energy Technology Data Exchange (ETDEWEB)

An inherent advantage of Integrated Coal Gasification Combined Cycle (IGCC) electric power generation is the ability to easily remove and recover sulfur. During the last several years, a number of new, improved sulfur removal and recovery processes have been commercialized. An assessment is given of alternative sulfur removal processes for IGCC based on the Texaco coal gasifier. The Selexol acid gas removal system, Claus sulfur recovery, and SCOT tail gas treating are currently used in Texaco-based IGCC. Other processes considered are: Purisol, Sulfinol-M, Selefning, 50% MDEA, Sulften, and LO-CAT. 2 tables.

1986-12-01

399

Greening plant growth bag  

UK PubMed Central (United Kingdom)

The utility model discloses a greening plant growth bag, which comprises a plant growth bag body composed of an inner layer, an outer layer and an intermediate layer. The inner layer is microporous, the outer layer is meshed, the intermediate layer consists of seeds, fertilizers and nutrient matrix between the inner layer and the outer layer, and mutually fitting connecting structures are arranged on opposite edges of the plant growth bag body. The greening plant growth bag is producible by factories, and the size of the greening plant growth bag is definable according to construction requirements. A plurality of greening plant growth bags are connected onto various side slopes or dams through the connecting structures, plant seeds are promoted to grow under simple watering and maintenance, rooting of the seeds on the various side slopes is guaranteed to conserve water and soil, and a wide area of vegetation and green side slopes is restored. The greening plant growth bag is convenient in construction, less in investment, wide in application range, not easy to be damaged by water, effective and capable of meeting requirements on quick protection and quick greening.

LE LI

400