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Sample records for deinococcus radiodurans engineered

  1. Non-coding RNA in Deinococcus radiodurans

    International Nuclear Information System (INIS)

    Chen Zhongzhong; Wang Liangyan; Lin Jun; Tian Bing; Hua Yuejin

    2006-01-01

    Researches on DNA damage and repair pathways of Deinococcus radiodurans show its extreme resistance to ionizing radiation, ultraviolet radiation and reactive oxygen species. Non-coding (ncRNA) RNAs are involved in a variety of processes such as transcriptional regulations, RNA processing and modification, mRNA translation, protein transportation and stability. The conserved secondary structures of intergenic regions of Deinococcus radiodurans R1 were predicted using Stochastic Context Free Grammar (SCFG) scan strategy. Results showed that 28 ncRNA families were present in the non-coding regions of the genome of Deinococcus radiodurans R1. Among these families, IRE is the largest family, followed by Histone3, tRNA, SECIS. DicF, ctRNA-pGA1 and tmRNA are one discovered in bacteria. Results from the comparison with other organisms showed that these ncRNA can be applied to the study of biological function of Deinococcus radiodurans and supply reference for the further study of DNA damage and repair mechanisms of this bacterium. (authors)

  2. Research progress on polar lipids of deinococcus radiodurans

    International Nuclear Information System (INIS)

    Feng Qiong; Tian Bing; Hua Yuejin

    2013-01-01

    Deinococcus radiodurans is extremely resistant to radiation, desiccation, oxidizing agents and other extreme conditions. One of the unique lipids in Deinococcus radiodurans is the polar lipid phosphoglycolipid with alkylamine as the main component. Alkylamine derived from fatty acids. The composition characteristic of lipids is one of the classification criterias of Deinococcus. This article provided an overview of the main features of the Deinococcus radiodurans and introduced special polar lipids that have been found as well as the taxonomy significances of such lipids. The research progress of the relationship between lipids and their resistance mechanisms and the prospects of special lipids in Deinococcus radidurans have also been discussed. (authors)

  3. The characteristics of micrococcus (deinococcus) radiodurans sark plasmids

    International Nuclear Information System (INIS)

    Sjarief, Sri Hariani; Kikuchi, Masahiro; Watanabe, Hiroshi.

    1994-01-01

    The characterization of micrococcus (deinococcus) radiodurans sark plasmids. This bacterium has been classified as a new genus deinococcus radiodurans which is resistant to gamma-rays. It can repair itself completely almost all of DNA damages including double strand breaks induced by gamma-rays up to about 5 KGy. To reveal the repair mechanism, several investigations had been done to develop a cloning vector available for the genetic analysis. For this purpose D. radiodurans Sark are to be prepared as a vector by studying the characteristics of its plasmid. Plasmids were isolated by electrophoresis using 0.6% low-melting-temperature agarose in TAE and run for 5.5 hours, followed by the identification. An antibiotic marker was also carried out in this experiment to identify its location in the genetic materials of the cell, beside making a restriction map of the plasmid. Results have shown that D. radiodurans Sark has 4 plasmids (P1, P2, P3, and P4) and the refampicin resistant genes were not found in the plasmid. (authors). 14 refs; 4 figs

  4. Metabolic engineering of deinococcus radiodurans based on computational analysis and functional genomics

    Energy Technology Data Exchange (ETDEWEB)

    Edwards, Jeremy, S.

    2005-02-02

    The objective of our work is to develop novel computational tools to analyze the Deinococcus radiodurans DNA repair pathways and the influence of the metabolic flux distribution on DNA repair. These tools will be applied to provide insights for metabolic engineering of strains capable of growing under nutrient poor conditions similar to those found in mixed contaminant sites of interest to the DOE. Over the entire grant period we accomplished all our specific aims and were also able to pursue new directions of research. Below, I will list the major accomplishments over the previous 3 years. (1) Performed Monte Carlo Simulations of RecA Mediated Pairing of Homologous DNA Molecules. (2) Developed a statistical approach to study the gene expression data from D. radiodurans. We have been studying the data from John Batista's. (3) Developed an expression profiling technology to generate very accurate and precise expression data. We followed up on results from John Batista's group using this approach. (4) Developed and put online a database for metabolic reconstructions. (5) We have developed and applied new Monte Carlo algorithms that are optimized for studying biological systems. (6) We developed a flux balance model for the D. radiodurans metabolic network

  5. Subterranean Microhabitat Dependent Intra Versus Extracellular Enzyme Secretion Capabilities of Deinococcus radiodurans

    Directory of Open Access Journals (Sweden)

    Jayant Biswas

    2015-04-01

    Full Text Available Deinococcus radiodurans is one of the most yet discovered extremophilic microbe, the isolation of which from the various habitats of Kotumsar cave is always a matter of enticement to discover its ecological economics. In the present work we studied the intra versus extracellular alkaline protease and glucose isomerase secretion capabilities of Deinococcus radiodurans; KCB21, KCB50, KCB93 isolated from three distinct subterranean niches of Kotumsar cave. The selected niches/zones were the entrance zone, transient zone and the deep inner zone from where the soil sediments were collected to isolate the bacterial strains. The results revealed high extracellular alkaline protease activity from the Deinococcus radiodurans strain which was isolated from the deeper zones of the cave, whereas no such phenomenon was revealed for glucose isomerase. The possible reason for the obtained results has been discussed.

  6. Engineering Deinococcus geothermailis for Bioremediation of High-Temperature Radioactive Waste Environments

    International Nuclear Information System (INIS)

    Brim, Hassan; Venkateswaran, Amudhan; Kostandarithes, Heather M.; Fredrickson, Jim K.; Daly, Michael J.

    2003-01-01

    Deinococcus geothermalis is an extremely radiation-resistant thermophilic bacterium closely related to the mesophile Deinococcus radiodurans, which is being engineered for in situ bioremediation of radioactive wastes

  7. Isolation and properties of plasmids from Deinococcus radiodurans Sark

    International Nuclear Information System (INIS)

    Sjarief, S.H.; Kikuchi, Masahiro; Kurita, Hiromi; Kitayama, Shigeru; Watanabe, Hiroshi.

    1990-05-01

    Radioresistant bacterium, Deinococcus radiodurans, can repair completely almost all of DNA damages including double strand breaks induced by gamma-rays up to about 5 kGy. In order to reveal the repair mechanism, it is necessary to develop a cloning vector available for the genetic analysis. We tried to isolate plasmids from D.radiodurans Sark strain. In the present paper the isolation and properties of plasmids were described. (author)

  8. Engineering Deinococcus radiodurans R1 for bioremediation of non radioactive and radioactive wastes facilitated by comparative genomics with Cupriavidus metallidurans CH34

    International Nuclear Information System (INIS)

    Badri, Hanene; Sghaier, Haitham; Barkallah, Insaf; Ben Salem, Issam; Wafa; Essouiss, Imen; Saied, Nadia; Saidi, M.; Gatri, Faten; Gatri, Maher; Boadabous, Abdellatifs; Leys, Natalie

    2009-01-01

    Deinococcus radiodurans R1 is a poly-extremophile for which a system of genetic transformation and manipulation has been developed and it is being engineered for in situ bioremediation of wastes particularly for cleanup of radioactive waste sites. In this study, additional attempts have been made to evaluate ''bioremediation determinants'' in the genome of D. radiodurans using a comparative-genomic approach with Cupriavidus metallidurans CH34, a multiple metal resistant bacterium. This resulted in the delineation of a set of ORFs that are common or peculiar to C. metallidurans and D. radiodurans. We identified 12 ORFs related to multidrug resistance efflux pumps as a special feature of C. metallidurans compared to D. radiodurans, which is the subject of further experimental work

  9. Small-molecule antioxidant proteome-shields in Deinococcus radiodurans.

    Directory of Open Access Journals (Sweden)

    Michael J Daly

    2010-09-01

    Full Text Available For Deinococcus radiodurans and other bacteria which are extremely resistant to ionizing radiation, ultraviolet radiation, and desiccation, a mechanistic link exists between resistance, manganese accumulation, and protein protection. We show that ultrafiltered, protein-free preparations of D. radiodurans cell extracts prevent protein oxidation at massive doses of ionizing radiation. In contrast, ultrafiltrates from ionizing radiation-sensitive bacteria were not protective. The D. radiodurans ultrafiltrate was enriched in Mn, phosphate, nucleosides and bases, and peptides. When reconstituted in vitro at concentrations approximating those in the D. radiodurans cytosol, peptides interacted synergistically with Mn(2+ and orthophosphate, and preserved the activity of large, multimeric enzymes exposed to 50,000 Gy, conditions which obliterated DNA. When applied ex vivo, the D. radiodurans ultrafiltrate protected Escherichia coli cells and human Jurkat T cells from extreme cellular insults caused by ionizing radiation. By establishing that Mn(2+-metabolite complexes of D. radiodurans specifically protect proteins against indirect damage caused by gamma-rays delivered in vast doses, our findings provide the basis for a new approach to radioprotection and insight into how surplus Mn budgets in cells combat reactive oxygen species.

  10. Design and Construction of Deinococcus Radiodurans for Biodegradation of Organic Toxins at Radioactive DOE Waste Sites

    International Nuclear Information System (INIS)

    Daly, Michael J.; Wackett, Lawrence P.; Fredrickson, James K.

    2001-01-01

    Seventy million cubic meters of ground and three trillion liters of groundwater have been contaminated by leaking radioactive waste generated in the United States during the Cold War. A cleanup technology is being developed based on the extremely radiation resistant bacterium Deinococcus radiodurans that is being engineered to express bioremediating functions. Research aimed at developing D. radiodurans for organic toxin degradation in highly radioactive waste sites containing radionuclides, heavy metals, and toxic organic compounds was started by this group.Work funded by the existing grant has already contributed to eleven papers on the fundamental biology of D. radiodurans and its design for bioremediation of highly radioactive waste environments

  11. Repair of DNA damage in Deinococcus radiodurans

    International Nuclear Information System (INIS)

    Evans, D.M.

    1984-01-01

    The repair of DNA lesions in Deinococcus radiodurans was examined with particular reference to DNA excision repair of ultraviolet light (UV) induced pyrimidine dimers. The characteristics of excision repair via UV endonucleases α and β in vivo varied with respect to (a) the substrate range of the enzymes, (b) the rate of repair of DNA damage (c) the requirement for a protein synthesised in response to DNA damage to attenuate exonuclease action at repairing regions. UV endonuclease α is postulated to incise DNA in a different manner from UV endonuclease β thus defining the method of subsequent repair. Several DNA damage specific endonuclease activities independent of α and β are described. Mutations of the uvsA, uvsF and uvsG genes resulted in an increase in single-strand breaks in response to DNA damage producing uncontrolled DNA degradation. Evidence is presented that these genes have a role in limiting the access of UV endonuclease β to DNA lesions. uvsF and uvsG are also shown to be linked to the mtoA gene. Mutation of uvsH and reo-1 produces further distinct phenotypes which are discussed. An overall model of excision repair of DNA damage in Deinococcus radiodurans is presented. (author)

  12. The three catalases in Deinococcus radiodurans: Only two show catalase activity.

    Science.gov (United States)

    Jeong, Sun-Wook; Jung, Jong-Hyun; Kim, Min-Kyu; Seo, Ho Seong; Lim, Heon-Man; Lim, Sangyong

    2016-01-15

    Deinococcus radiodurans, which is extremely resistant to ionizing radiation and oxidative stress, is known to have three catalases (DR1998, DRA0146, and DRA0259). In this study, to investigate the role of each catalase, we constructed catalase mutants (Δdr1998, ΔdrA0146, and ΔdrA0259) of D. radiodurans. Of the three mutants, Δdr1998 exhibited the greatest decrease in hydrogen peroxide (H2O2) resistance and the highest increase in intracellular reactive oxygen species (ROS) levels following H2O2 treatments, whereas ΔdrA0146 showed no change in its H2O2 resistance or ROS level. Catalase activity was not attenuated in ΔdrA0146, and none of the three bands detected in an in-gel catalase activity assay disappeared in ΔdrA0146. The purified His-tagged recombinant DRA0146 did not show catalase activity. In addition, the phylogenetic analysis of the deinococcal catalases revealed that the DR1998-type catalase is common in the genus Deinococcus, but the DRA0146-type catalase was found in only 4 of 23 Deinococcus species. Taken together, these results indicate that DR1998 plays a critical role in the anti-oxidative system of D. radiodurans by detoxifying H2O2, but DRA0146 does not have catalase activity and is not involved in the resistance to H2O2 stress. Copyright © 2015 Elsevier Inc. All rights reserved.

  13. ParA encoded on chromosome II of Deinococcus radiodurans binds ...

    Indian Academy of Sciences (India)

    2013-07-22

    Jul 22, 2013 ... Introduction. Cell division ..... Subsequently, the level of total FtsZ (FtsZ + FtsZ-. YFP) in cells ... could affect the productive pattern of FtsZ localization and .... maintenance and disassembly of the Z ring. Nat. ... cation tolerance of plants sensitizes Deinococcus radiodurans ... metal shadowing and decoration.

  14. Deinococcus radiodurans strain R1 contains N6-methyladenine in its genome

    International Nuclear Information System (INIS)

    Prasad, Bhaskar Jyoti; Sabnis, Ketaki; Deobagkar, Deepti D.; Deobagkar, Dileep N.

    2005-01-01

    Methylation of DNA is known to be involved in DNA repair mechanisms in bacteria. Deinococcus radiodurans strain R1 on exposure to high radiation undergoes significant DNA damage, which is repaired without mutations. However, the presence of modified nucleotides has not been reported in its genome. We report here the detection of N6-methyladenine in the genome of D. radiodurans strain R1 using immunochemical techniques. This N6-methyladenine is not a part of GATC restriction-modification system. D. radiodurans cell extract also exhibited a DNA adenine methyltransferase activity which was reduced in the early post-irradiation recovery phase

  15. Effect of Deinococcus radiodurans on uptake of 134Cs by Brassica oleracea

    International Nuclear Information System (INIS)

    Zhu Cong; Guo Jiangfeng

    2008-01-01

    Deinococcus radiodurans was inoculated into the soil which was spiked with 134 Cs to investigate its effect on chemical speciation of 134 Cs. The relationship between chemical speciation of 134 Cs and its absorbtion capacity by cabbage (Brassica oleracea) in the presence of D. radiodurans was also investigated. The results showed that an increase of 28.64%-38.17 % in content of 134 Cs in residual phase was observed with presence of D. radiodurans in comparison with the aseptic control. The amounts of radiocesium uptaken by cabbage were about 12100Bq/g under aseptic conditions, however, which were about 8500Bq/g with the presence of D. radiodurans. The proportion of 134 Cs taken up by cabbage decreased about 29% in comparison with the aseptic control. The chemical speciation could be influenced by D. radiodurans so that its uptake by plants could be reduced. (authors)

  16. Final Report for Grant No. DE-FG02-97ER62492 ''Engineering Deinococcus radiodurans for Metal Remediation in Radioactive Mixed Waste Sites''

    International Nuclear Information System (INIS)

    Michael J.; Daly, Ph.D.

    2005-01-01

    The groundwater and sediments of numerous U. S. Department of Energy (DOE) field sites are contaminated with mixtures of heavy metals (e.g., Hg, Cr, Pd) and radionuclides (e.g., U, Tc), as well as the fuel hydrocarbons benzene, toluene, ethylbenzene and xylenes (BTEX); chlorinated hydrocarbons, such as trichloroethylene (TCE); and polychlorinated biphenyls (PCBs). The remediation of such mixed wastes constitutes an immediate and complex waste management challenge for DOE, particularly in light of the costliness and limited efficacy of current physical and chemical strategies for treating mixed wastes. In situ bioremediation via natural microbial processes (e.g., metal reduction) remains a potent, potentially cost-effective approach to the reductive immobilization or detoxification of environmental contaminants. Seventy million cubic meters of soil and three trillion liters of groundwater have been contaminated by leaking radioactive waste generated in the United States during the Cold War. A cleanup technology is being developed based on the extremely radiation resistant bacterium Deinococcus radiodurans. Our recent isolation and characterization of D. radiodurans from a variety of DOE environments, including highly radioactive sediments beneath one of the leaking tanks (SX-108) at the Hanford Site in south-central Washington state, underscores the potential for this species to survive in such extreme environments. Research aimed at developing D. radiodurans for metal remediation in radioactive waste sites was started by this group in September 1997 with support from DOE NABIR grant DE-FG02-97ER62492. Our grant was renewed for the period 2000-2003, which includes work on the thermophilic radiation resistant bacterium Deinococcus geothermalis. Work funded by the existing grant contributed to 18 papers in the period 1997-2004 on the fundamental biology of D. radiodurans and its design for bioremediation of radioactive waste environments. Our progress since September

  17. The three catalases in Deinococcus radiodurans: Only two show catalase activity

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Sun-Wook [Research Division for Biotechnology, Korea Atomic Energy Research Institute, Jeongeup, 580-185 (Korea, Republic of); Department of Biological Sciences, College of Biological Sciences and Biotechnology, Chungnam National University, Daejeon, 305-764 (Korea, Republic of); Jung, Jong-Hyun; Kim, Min-Kyu; Seo, Ho Seong [Research Division for Biotechnology, Korea Atomic Energy Research Institute, Jeongeup, 580-185 (Korea, Republic of); Lim, Heon-Man [Department of Biological Sciences, College of Biological Sciences and Biotechnology, Chungnam National University, Daejeon, 305-764 (Korea, Republic of); Lim, Sangyong, E-mail: saylim@kaeri.re.kr [Research Division for Biotechnology, Korea Atomic Energy Research Institute, Jeongeup, 580-185 (Korea, Republic of)

    2016-01-15

    Deinococcus radiodurans, which is extremely resistant to ionizing radiation and oxidative stress, is known to have three catalases (DR1998, DRA0146, and DRA0259). In this study, to investigate the role of each catalase, we constructed catalase mutants (Δdr1998, ΔdrA0146, and ΔdrA0259) of D. radiodurans. Of the three mutants, Δdr1998 exhibited the greatest decrease in hydrogen peroxide (H{sub 2}O{sub 2}) resistance and the highest increase in intracellular reactive oxygen species (ROS) levels following H{sub 2}O{sub 2} treatments, whereas ΔdrA0146 showed no change in its H{sub 2}O{sub 2} resistance or ROS level. Catalase activity was not attenuated in ΔdrA0146, and none of the three bands detected in an in-gel catalase activity assay disappeared in ΔdrA0146. The purified His-tagged recombinant DRA0146 did not show catalase activity. In addition, the phylogenetic analysis of the deinococcal catalases revealed that the DR1998-type catalase is common in the genus Deinococcus, but the DRA0146-type catalase was found in only 4 of 23 Deinococcus species. Taken together, these results indicate that DR1998 plays a critical role in the anti-oxidative system of D. radiodurans by detoxifying H{sub 2}O{sub 2}, but DRA0146 does not have catalase activity and is not involved in the resistance to H{sub 2}O{sub 2} stress. - Highlights: • The dr1998 mutant strain lost 90% of its total catalase activity. • Increased ROS levels and decreased H{sub 2}O{sub 2} resistance were observed in dr1998 mutants. • Lack of drA0146 did not affect any oxidative stress-related phenotypes. • The purified DRA0146 did not show catalase activity.

  18. The three catalases in Deinococcus radiodurans: Only two show catalase activity

    International Nuclear Information System (INIS)

    Jeong, Sun-Wook; Jung, Jong-Hyun; Kim, Min-Kyu; Seo, Ho Seong; Lim, Heon-Man; Lim, Sangyong

    2016-01-01

    Deinococcus radiodurans, which is extremely resistant to ionizing radiation and oxidative stress, is known to have three catalases (DR1998, DRA0146, and DRA0259). In this study, to investigate the role of each catalase, we constructed catalase mutants (Δdr1998, ΔdrA0146, and ΔdrA0259) of D. radiodurans. Of the three mutants, Δdr1998 exhibited the greatest decrease in hydrogen peroxide (H_2O_2) resistance and the highest increase in intracellular reactive oxygen species (ROS) levels following H_2O_2 treatments, whereas ΔdrA0146 showed no change in its H_2O_2 resistance or ROS level. Catalase activity was not attenuated in ΔdrA0146, and none of the three bands detected in an in-gel catalase activity assay disappeared in ΔdrA0146. The purified His-tagged recombinant DRA0146 did not show catalase activity. In addition, the phylogenetic analysis of the deinococcal catalases revealed that the DR1998-type catalase is common in the genus Deinococcus, but the DRA0146-type catalase was found in only 4 of 23 Deinococcus species. Taken together, these results indicate that DR1998 plays a critical role in the anti-oxidative system of D. radiodurans by detoxifying H_2O_2, but DRA0146 does not have catalase activity and is not involved in the resistance to H_2O_2 stress. - Highlights: • The dr1998 mutant strain lost 90% of its total catalase activity. • Increased ROS levels and decreased H_2O_2 resistance were observed in dr1998 mutants. • Lack of drA0146 did not affect any oxidative stress-related phenotypes. • The purified DRA0146 did not show catalase activity.

  19. Bioprecipitation of uranium from alkaline waste solutions using recombinant Deinococcus radiodurans

    Energy Technology Data Exchange (ETDEWEB)

    Kulkarni, Sayali; Ballal, Anand; Apte, Shree Kumar, E-mail: aptesk@barc.gov.in

    2013-11-15

    Highlights: • Deinococcus radiodurans was genetically engineered to overexpress alkaline phosphatase (PhoK). • Deino-PhoK bioprecipitated U efficiently over a wide range of input U concentration. • A maximal loading of 10.7 g U/g of biomass at 10 mM input U was observed. • Radioresistance and U precipitation by Deino-PhoK remained unaffected by γ radiation. • Immobilization of Deino-PhoK facilitated easy separation of precipitated U. -- Abstract: Bioremediation of uranium (U) from alkaline waste solutions remains inadequately explored. We engineered the phoK gene (encoding a novel alkaline phosphatase, PhoK) from Sphingomonas sp. for overexpression in the radioresistant bacterium Deinococcus radiodurans. The recombinant strain thus obtained (Deino-PhoK) exhibited remarkably high alkaline phosphatase activity as evidenced by zymographic and enzyme activity assays. Deino-PhoK cells could efficiently precipitate uranium over a wide range of input U concentrations. At low uranyl concentrations (1 mM), the strain precipitated >90% of uranium within 2 h while a high loading capacity of around 10.7 g U/g of dry weight of cells was achieved at 10 mM U concentration. Uranium bioprecipitation by Deino-PhoK cells was not affected in the presence of Cs and Sr, commonly present in intermediate and low level liquid radioactive waste, or after exposure to very high doses of ionizing radiation. Transmission electron micrographs revealed the extracellular nature of bioprecipitated U, while X-ray diffraction and fluorescence analysis identified the precipitated uranyl phosphate species as chernikovite. When immobilized into calcium alginate beads, Deino-PhoK cells efficiently removed uranium, which remained trapped in beads, thus accomplishing physical separation of precipitated uranyl phosphate from solutions. The data demonstrate superior ability of Deino-PhoK, over earlier reported strains, in removal of uranium from alkaline solutions and its potential use in

  20. Characterization of the radioresistance in the radioresistant bacterium deinococcus radiodurans

    International Nuclear Information System (INIS)

    Kong Xiangrong; Du Zeji

    1999-01-01

    The radioresistance of wild type Deinococcus radiodurans KD8301 and the factors affecting the radioresistance were investigated. KH3111 which was a DNA repair mutant of KD8301 (Zeji Du, 1998) was used to be compared with KD8301. Deinococcus radiodurans was discovered by Anderson et al (1956) in X-ray sterilized canned meat that was found to have undergone spoilage. this bacterium and other species of this genus share extreme resistance to ionizing radiation and other agents that damage DNA. Wild type KD8301 and its sensitive mutant KH3111 were irradiated with 60 Co γ-ray at the dose range 0.5 ∼ 10 kGy. Dose-survival fraction curves were made and the radio resistances were determined by LD 99 . The relative contents of DNA in cells were measured by Fluorescence Spectrophotometry (Freedman and Bruce, 1971). The results indicated that wild type KD8301 possesses more radioresistant than its mutant KH3111, LD99 were 9.5 kGy and 2.4 kGy respectively. KD8301 grown at exponential phase showed a decreased resistance to radiation, and the LD99 was 5.1 kGy. No differences of DNA/protein in cells were found between the exponential phase and the stationary phase. The results could be concluded that wild type KD8301 possesses remarkable radioresistance, but this ability was decreased or disappeared after mutation (in KH3111). None DNA relative content other than the growth stages were determinant factors of radioresistance in Deinococcus radiodurans. This results were different from other report (Dickie N et al, 1990). The cellular mechanisms might be the deference's of the bacterium cell morphology between the exponential phase and the stationary phase. Recently, the mutation site of KH3111 which was mutated chemically from wild type KD8301 was identified (Zeji Du, 1998). One base pair changed in the novel gene pprA which was isolated from KD8301 genomic DNA. This point mutation was confirmed to be responsible for the sensitivity of KH3111 to γ-ray and other DNA

  1. THE ROLE OF IRON IN Deinococcus radiodurans ENGINEERED FOR GROWTH ON TOLUENE AND THE ROLE OF MANGANESE IN THE EXTREME RADIATION RESISTANCE PHENOTYPE

    International Nuclear Information System (INIS)

    Hassan Brim; Elena K. Gaidamakova; Vera Y. Matrosova; Min Zhai; Amudhan Venkateswaran; Marina Omelchenko; Kira S. Makarova; Lawrence P. Wackett; James K. Fredrickson; Michael J. Daly

    2004-01-01

    Toluene and other fuel hydrocarbons are commonly found in association with radionuclides at numerous Department of Energy (DOE) sites, frequently occurring together with Cr(VI) and other heavy metals. In this study, the extremely radiation resistant bacterium Deinococcus radiodurans was engineered for complete toluene mineralization by cloned expression of tod and xyl genes of Pseudomonas putida. The recombinant Tod/Xyl strain showed significant incorporation of carbon from the toluene aromatic ring into cellular macromolecules and carbon dioxide, in the absence or presence of chronic radiation. We have shown that intracellular iron concentrations in wild-type D. radiodurans in minimal medium are exceptionally low and not sufficient to support growth on toluene using Fe-dependent oxygenases cloned from P. putida. Introducing the fur mutation into D. radiodurans increased intracellular Fe levels, and imparted on the engineered strain the ability to grow on meta-toluate as the sole carbon and energy source. The organism's native Cr(VI) reduction capabilities were facilitated by toluene when present as the sole carbon and energy source in natural sediment analogues of DOE contaminated environments. The engineered bacteria were able to oxidize toluene under both minimal and complex nutrient conditions, which is important since both conditions have environmental equivalents in the context of bioremediation processes. As such, the Tod/Xyl strain is providing a model for understanding the role of Fe and reduction of metals coupled to organic contaminant oxidation in aerobic radionuclide contaminated sediments. We have shown that D. radiodurans contains high intracellular manganese levels, and that Mn restriction sensitizes cells to irradiation. We propose that the unusually high Mn/Fe ratio of D. radiodurans facilitates survival by quenching oxidative stress during recovery.

  2. THE ROLE OF IRON IN Deinococcus radiodurans ENGINEERED FOR GROWTH ON TOLUENE AND THE ROLE OF MANGANESE IN THE EXTREME RADIATION RESISTANCE PHENOTYPE

    Energy Technology Data Exchange (ETDEWEB)

    Hassan Brim; Elena K. Gaidamakova; Vera Y. Matrosova; Min Zhai; Amudhan Venkateswaran; Marina Omelchenko; Kira S. Makarova; Lawrence P. Wackett; James K. Fredrickson; Michael J. Daly

    2004-03-17

    Toluene and other fuel hydrocarbons are commonly found in association with radionuclides at numerous Department of Energy (DOE) sites, frequently occurring together with Cr(VI) and other heavy metals. In this study, the extremely radiation resistant bacterium Deinococcus radiodurans was engineered for complete toluene mineralization by cloned expression of tod and xyl genes of Pseudomonas putida. The recombinant Tod/Xyl strain showed significant incorporation of carbon from the toluene aromatic ring into cellular macromolecules and carbon dioxide, in the absence or presence of chronic radiation. We have shown that intracellular iron concentrations in wild-type D. radiodurans in minimal medium are exceptionally low and not sufficient to support growth on toluene using Fe-dependent oxygenases cloned from P. putida. Introducing the fur mutation into D. radiodurans increased intracellular Fe levels, and imparted on the engineered strain the ability to grow on meta-toluate as the sole carbon and energy source. The organism's native Cr(VI) reduction capabilities were facilitated by toluene when present as the sole carbon and energy source in natural sediment analogues of DOE contaminated environments. The engineered bacteria were able to oxidize toluene under both minimal and complex nutrient conditions, which is important since both conditions have environmental equivalents in the context of bioremediation processes. As such, the Tod/Xyl strain is providing a model for understanding the role of Fe and reduction of metals coupled to organic contaminant oxidation in aerobic radionuclide contaminated sediments. We have shown that D. radiodurans contains high intracellular manganese levels, and that Mn restriction sensitizes cells to irradiation. We propose that the unusually high Mn/Fe ratio of D. radiodurans facilitates survival by quenching oxidative stress during recovery.

  3. Identifying the Proteins that Mediate the Ionizing Radiation Resistance of Deinococcus Radiodurans R1

    Energy Technology Data Exchange (ETDEWEB)

    Battista, John R

    2010-02-22

    The primary objectives of this proposal was to define the subset of proteins required for the ionizing radiation (IR) resistance of Deinococcus radiodurans R1, characterize the activities of those proteins, and apply what was learned to problems of interest to the Department of Energy.

  4. Characterization of radiation-induced proteins in Deinococcus radiodurans

    International Nuclear Information System (INIS)

    Tanaka, A.; Watanabe, H.; Nozawa, R.; Hu, Q.; Kitayama, S.

    1992-01-01

    Induction of proteins after gamma-irradiation in Deinococcus radiodurans were investigated. 10 proteins were induced and about 15 proteins were reduced after irradiation with 6kGy. These proteins were classified to four groups by responses to gamma-rays, UV light, mitomycin C(MMC) treatment and heating. Additional studies were carried out for the characterization of two induced proteins. One protein was induced by gamma-rays, UV light as well as heating. This protein appeared to be a glycoprotein from its reaction with lectin. From the amino acid sequences of N-terminal and internal region, it was found that this protein is homologous to EF-Tu protein of E. coli. Meanwhile the other protein was induced not only by gamma-rays but also by UV light and MMC treatment. This protein seems to be a new enzyme as it has no homology to the known proteins which have ever been analyzed. No accumulations of these two proteins were observed in radiation sensitive strain of D. radiodurans and in both of E. coli and Bacillus pumilus, suggesting that induction of these two proteins would be specific for high resistant strain. (author)

  5. Final Report for Grant No. DE-FG02-98ER62583 ''Functional Analysis of the Genome Sequence of Deinococcus radiodurans''

    International Nuclear Information System (INIS)

    Daly, Michael J.

    2003-01-01

    Extremophiles are nearly always defined with singular characteristics that allow existence within a singular extreme environment. The bacterium Deinococcus radiodurans qualifies as a polyextremeophile, showing remarkable resistance to a range of damage caused by ionizing radiation, dessication, ultraviolet radiation, oxidizing agents, and electrophilic mutagens. D. radiodurans is most famous for its extreme resistance to ionizing radiation; it not only can grow continuously in the presence of chronic radiation (6,000 rad per hour), but it can survive acute exposures to gamma radiation that exceed 1,500,000 rads without lethality or induced mutation. These characteristics were the impetus for sequencing its genome. We completed an extensive comparative sequence analysis of the Deinococcus radiodurans (strain R1) genome. Deinococcus is the first representative with a completely sequenced genome from a bacterial branch of extremophiles - the Thermus/Deinococcus group. Phylogenetic tree analysis, combined with the identification of several synapomorphies between Thermus and Deinococcus, support that it is a very ancient branch localized in the vicinity of the bacterial tree root. Distinctive features of the Deinoccoccus genome as well as features shared with other free-living bacteria were revealed by comparison of its proteome to a collection of Clusters of Orthologous Groups of proteins (COGs). Analysis of paralogs in Deinococcus has revealed some unique protein families. In addition, specific expansions of several protein families including phosphatases, proteases, acyl transferases and MutT pyrophosphohydrolases, were detected. Genes that potentially affect DNA repair and recombination were investigated in detail. Some proteins appear to have been horizontally transferred from eukaryotes, and are not present in other bacteria. For example, three proteins homologous to plant desiccation-resistance proteins were identified and these are particularly interesting

  6. Comparative genomics of Thermus thermophilus and Deinococcus radiodurans: divergent routes of adaptation to thermophily and radiation resistance

    Directory of Open Access Journals (Sweden)

    Daly Michael J

    2005-10-01

    Full Text Available Abstract Background Thermus thermophilus and Deinococcus radiodurans belong to a distinct bacterial clade but have remarkably different phenotypes. T. thermophilus is a thermophile, which is relatively sensitive to ionizing radiation and desiccation, whereas D. radiodurans is a mesophile, which is highly radiation- and desiccation-resistant. Here we present an in-depth comparison of the genomes of these two related but differently adapted bacteria. Results By reconstructing the evolution of Thermus and Deinococcus after the divergence from their common ancestor, we demonstrate a high level of post-divergence gene flux in both lineages. Various aspects of the adaptation to high temperature in Thermus can be attributed to horizontal gene transfer from archaea and thermophilic bacteria; many of the horizontally transferred genes are located on the single megaplasmid of Thermus. In addition, the Thermus lineage has lost a set of genes that are still present in Deinococcus and many other mesophilic bacteria but are not common among thermophiles. By contrast, Deinococcus seems to have acquired numerous genes related to stress response systems from various bacteria. A comparison of the distribution of orthologous genes among the four partitions of the Deinococcus genome and the two partitions of the Thermus genome reveals homology between the Thermus megaplasmid (pTT27 and Deinococcus megaplasmid (DR177. Conclusion After the radiation from their common ancestor, the Thermus and Deinococcus lineages have taken divergent paths toward their distinct lifestyles. In addition to extensive gene loss, Thermus seems to have acquired numerous genes from thermophiles, which likely was the decisive contribution to its thermophilic adaptation. By contrast, Deinococcus lost few genes but seems to have acquired many bacterial genes that apparently enhanced its ability to survive different kinds of environmental stresses. Notwithstanding the accumulation of

  7. Gene fusions with lacZ by duplication insertion in the radioresistant bacterium Deinococcus radiodurans

    International Nuclear Information System (INIS)

    Lennon, E.; Minton, K.W.

    1990-01-01

    Deinococcus radiodurans is the most-studied species of a eubacterial family characterized by extreme resistance to DNA damage. We have focused on developing molecular biological techniques to investigate the genetics of this organism. We report construction of lacZ gene fusions by a method involving both in vitro splicing and the natural transformation of D. radiodurans. Numerous fusion strains were identified by expression of beta-galactosidase. Among these fusion strains, several were inducible by exposure to the DNA-damaging agent mitomycin C, and four of the inducible fusion constructs were cloned in Escherichia coli. Hybridization studies indicate that one of the damage-inducible genes contains a sequence reiterated throughout the D. radiodurans chromosome. Survival measurements show that two of the fusion strains have increased sensitivity to mitomycin C, suggesting that the fusions within these strains inactivate repair functions

  8. Impact of low-temperature plasmas on Deinococcus radiodurans and biomolecules

    Science.gov (United States)

    Mogul, Rakesh; Bol'shakov, Alexander A.; Chan, Suzanne L.; Stevens, Ramsey M.; Khare, Bishun N.; Meyyappan, M.; Trent, Jonathan D.

    2003-01-01

    The effects of cold plasma on Deinococcus radiodurans, plasmid DNA, and model proteins were assessed using microbiological, spectrometric, and biochemical techniques. In low power O(2) plasma (approximately 25 W, approximately 45 mTorr, 90 min), D. radiodurans, a radiation-resistant bacterium, showed a 99.999% reduction in bioburden. In higher power O(2) plasma (100 W and 500 mTorr), the reduction rate increased about 10-fold and observation by atomic force microscopy showed significant damage to the cell. Damage to cellular lipids, proteins, and chromosome was indicated by losses of infrared spectroscopic peaks at 2930, 1651, 1538, and 1245 cm(-1), respectively. In vitro experiments show that O(2) plasmas induce DNA strand scissions and cross-linking as well as reduction of enzyme activity. The observed degradation and removal of biomolecules was power-dependent. Exposures to 200 W at 500 mTorr removed biomolecules to below detection limits in 60 s. Emission spectroscopy indicated that D. radiodurans cells were volatilized into CO(2), CO, N(2), and H(2)O, confirming that these plasmas were removing complex biological matter from surfaces. A CO(2) plasma was not as effective as the O(2) plasma, indicating the importance of plasma composition and the dominant role of chemical degradation. Together, these findings have implications for NASA planetary protection schemes and for the contamination of Mars.

  9. UvrD in Deinococcus radiodurans is optimized for processing G-quadruplex DNA

    International Nuclear Information System (INIS)

    Das, Anubrata; Misra, H.S.

    2015-01-01

    Deinococcus radiodurans R1 is a radiation resistant Gram-positive bacterium capable of tolerating very high doses of DNA-damaging agents such as gamma radiation (D10 ∼ 12kGy) desiccation (∼ 5% relative humidity), UVC radiation (D10 ∼ 800J/m 2 ) and hydrogen peroxide (40 mM). It achieves this by using a complex regulatory mechanism and novel proteins. Recently bioinformatic analysis showed several stretches of guanine runs in D.radiodurans genome, which could form G-quartets. The role of G-quartets in regulatory processes is well documented in various organisms. The presence of G -quartets in D. radiodurans means that there are regulatory or structural proteins which would bind to these elements. Several proteins are known to bind G-quartets. Finding the proteins which would bind to G4 DNA is difficult as no specific motifs are available for binding these elements. Also most of the known proteins that are shown to bind to G-quadruplex DNA are of eukaryotic nature. To overcome these challenges we defined a set of known G-quadruplex binding proteins and used a smith-waterman algorithm with our own scoring matrix to homologs of G-quadruplex binding proteins in D.radiodurans. Using bioinformatics analysis, we showed that UvrD (DR 1775) of D. radiodurans has ability to bind/translocate along G-quadruplex DNA, a novel feature in prokaryotes. The translocase activity of DR1775 is ATP specific and this ATPase activity is attenuated by ssDNA. Data supporting UvrD of D. radiodurans as a G-quadruplex DNA metabolizing proteins would be presented. (author)

  10. Effect of N+ beam exposure on the activities of Mn-SOD and catalase in deinococcus radiodurans

    International Nuclear Information System (INIS)

    Song Daojun; Chen Ruolei; Wu Lifang; Li Hong; Yao JIanming; Shao Chunlin; Wu Lijun; Yu Zengliang

    2000-01-01

    Though the radiation-resistant bacteria Deinococcus radiodurans (D. radiodurans) have a high resistance to the lethal and mutagenic effects of many DNA-damaging agents, the mechanisms involved in the response of these bacteria to oxidative stress are poorly understood. The superoxide dismutase (SOD) and catalase (CAT) activities produced in bacteria (D. radiodurans AS1.633) and their change caused by 20 keV N'+ beam exposure were examined. Results showed that the activities of the enzymes were increased in the case of N + beam exposure from 8 x 10 14 ions/cm 2 to 6 x 10 15 ions/cm 2 . In addition, the treatment of H 2 O 2 and [CHCl 3 + CH 3 CH 2 OH] and the measurement of absorption spectrum showed that the increase of whole SOD activity resulted from inducible activities of Mn-SOD in (a sub-type) D. radiodurans AS1.633. These results suggested that these bacteria possess inducible defense mechanisms against the deleterious effects of oxidization

  11. Preserving genome integrity: the DdrA protein of Deinococcus radiodurans R1.

    Science.gov (United States)

    Harris, Dennis R; Tanaka, Masashi; Saveliev, Sergei V; Jolivet, Edmond; Earl, Ashlee M; Cox, Michael M; Battista, John R

    2004-10-01

    The bacterium Deinococcus radiodurans can withstand extraordinary levels of ionizing radiation, reflecting an equally extraordinary capacity for DNA repair. The hypothetical gene product DR0423 has been implicated in the recovery of this organism from DNA damage, indicating that this protein is a novel component of the D. radiodurans DNA repair system. DR0423 is a homologue of the eukaryotic Rad52 protein. Following exposure to ionizing radiation, DR0423 expression is induced relative to an untreated control, and strains carrying a deletion of the DR0423 gene exhibit increased sensitivity to ionizing radiation. When recovering from ionizing-radiation-induced DNA damage in the absence of nutrients, wild-type D. radiodurans reassembles its genome while the mutant lacking DR0423 function does not. In vitro, the purified DR0423 protein binds to single-stranded DNA with an apparent affinity for 3' ends, and protects those ends from nuclease degradation. We propose that DR0423 is part of a DNA end-protection system that helps to preserve genome integrity following exposure to ionizing radiation. We designate the DR0423 protein as DNA damage response A protein.

  12. Preserving genome integrity: the DdrA protein of Deinococcus radiodurans R1.

    Directory of Open Access Journals (Sweden)

    Dennis R Harris

    2004-10-01

    Full Text Available The bacterium Deinococcus radiodurans can withstand extraordinary levels of ionizing radiation, reflecting an equally extraordinary capacity for DNA repair. The hypothetical gene product DR0423 has been implicated in the recovery of this organism from DNA damage, indicating that this protein is a novel component of the D. radiodurans DNA repair system. DR0423 is a homologue of the eukaryotic Rad52 protein. Following exposure to ionizing radiation, DR0423 expression is induced relative to an untreated control, and strains carrying a deletion of the DR0423 gene exhibit increased sensitivity to ionizing radiation. When recovering from ionizing-radiation-induced DNA damage in the absence of nutrients, wild-type D. radiodurans reassembles its genome while the mutant lacking DR0423 function does not. In vitro, the purified DR0423 protein binds to single-stranded DNA with an apparent affinity for 3' ends, and protects those ends from nuclease degradation. We propose that DR0423 is part of a DNA end-protection system that helps to preserve genome integrity following exposure to ionizing radiation. We designate the DR0423 protein as DNA damage response A protein.

  13. Synthesis and extracellular accumulation of silver nanoparticles by employing radiation-resistant Deinococcus radiodurans, their characterization, and determination of bioactivity

    Directory of Open Access Journals (Sweden)

    Kulkarni RR

    2015-01-01

    Full Text Available Rasika R Kulkarni, Nayana S Shaiwale, Dileep N Deobagkar, Deepti D Deobagkar Molecular Biology Research Laboratory, Center of Advanced Studies, Department of Zoology, University of Pune, Pune, India Abstract: There has been rapid progress in exploring microorganisms for green synthesis of nanoparticles since microbes show extraordinary diversity in terms of species richness and niche localization. Microorganisms are easy to culture using relatively inexpensive and simple nutrients under varied conditions of temperature, pressure, pH, etc. In this work, Deinococcus radiodurans that possesses the ability to withstand extremely high radiation and desiccation stress has been employed for the synthesis of silver nanoparticles (AgNPs. D. radiodurans was able to accumulate AgNPs in medium under various conditions, and process optimization was carried out with respect to time, temperature, pH, and concentration of silver salt. AgNPs were characterized using UV/vis spectroscopy, scanning electron microscopy, transmission electron microscopy, X-ray diffraction, energy-dispersive X-ray spectroscopy, and Fourier transform infrared spectroscopy. The microbially synthesized AgNPs exhibited good antimicrobial activity against both Gram-negative and Gram-positive organisms and anti-biofouling activity. Their ability to inhibit growth and proliferation of cancer cell line was also examined, and it could be seen that AgNPs synthesized using D. radiodurans exhibited excellent anticancer activity. Keywords: Deinococcus radiodurans, silver nanoparticles, anticancer, radiation resistance, antibacterial, anti-biofouling 

  14. Deciphering peculiar protein-protein interacting modules in Deinococcus radiodurans

    Directory of Open Access Journals (Sweden)

    Barkallah Insaf

    2009-04-01

    Full Text Available Abstract Interactomes of proteins under positive selection from ionizing-radiation-resistant bacteria (IRRB might be a part of the answer to the question as to how IRRB, particularly Deinococcus radiodurans R1 (Deira, resist ionizing radiation. Here, using the Database of Interacting Proteins (DIP and the Protein Structural Interactome (PSI-base server for PSI map, we have predicted novel interactions of orthologs of the 58 proteins under positive selection in Deira and other IRRB, but which are absent in IRSB. Among these, 18 domains and their interactomes have been identified in DNA checkpoint and repair; kinases pathways; energy and nucleotide metabolisms were the important biological processes that were found to be involved. This finding provides new clues to the cellular pathways that can to be important for ionizing-radiation resistance in Deira.

  15. Deinococcus geothermalis: The Pool of Extreme Radiation Resistance Genes Shrinks

    Energy Technology Data Exchange (ETDEWEB)

    Makarova, Kira S.; Omelchenko, Marina V.; Gaidamakova, Elena K.; Matrosova, Vera Y.; Vasilenko, Alexander; Zhai, Min; Lapidus, Alla; Copeland, Alex; Kim, Edwin; Land, Miriam; Mavrommatis, Konstantinos; Pitluck, Samuel; Richardson, Paul M.; Detter, Chris; Brettin, Thomas; Saunders, Elizabeth; Lai, Barry; Ravel, Bruce; Kemner, Kenneth M.; Wolf, Yuri I.; Sorokin, Alexander; Gerasimova, Anna V.; Gelfand, Mikhail S.; Fredrickson, James K.; Koonin, Eugene V.; Daly, Michael J.

    2007-07-24

    Bacteria of the genus Deinococcus are extremely resistant to ionizing radiation (IR), ultraviolet light (UV) and desiccation. The mesophile Deinococcus radiodurans was the first member of this group whose genome was completely sequenced. Analysis of the genome sequence of D. radiodurans, however, failed to identify unique DNA repair systems. To further delineate the genes underlying the resistance phenotypes, we report the whole-genome sequence of a second Deinococcus species, the thermophile Deinococcus geothermalis, which at itsoptimal growth temperature is as resistant to IR, UV and desiccation as D. radiodurans, and a comparative analysis of the two Deinococcus genomes. Many D. radiodurans genes previously implicated in resistance, but for which no sensitive phenotype was observed upon disruption, are absent in D. geothermalis. In contrast, most D. radiodurans genes whose mutants displayed a radiation-sensitive phenotype in D. radiodurans are conserved in D. geothermalis. Supporting the existence of a Deinococcus radiation response regulon, a common palindromic DNA motif was identified in a conserved set of genes associated with resistance, and a dedicated transcriptional regulator was predicted. We present the case that these two species evolved essentially the same diverse set of gene families, and that the extreme stress-resistance phenotypes of the Deinococcus lineage emerged progressively by amassing cell-cleaning systems from different sources, but not by acquisition of novel DNA repair systems. Our reconstruction of the genomic evolution of the Deinococcus-Thermus phylum indicates that the corresponding set of enzymes proliferated mainly in the common ancestor of Deinococcus. Results of the comparative analysis weaken the arguments for a role of higher-order chromosome alignment structures in resistance; more clearly define and substantially revise downward the number of uncharacterized genes that might participate in DNA repair and contribute to

  16. High-resolution structure of the antibiotic resistance protein NimA from Deinococcus radiodurans

    International Nuclear Information System (INIS)

    Leiros, Hanna-Kirsti S.; Tedesco, Consiglia; McSweeney, Seán M.

    2008-01-01

    In this paper, the 1.2 Å atomic resolution crystal structure of the 5-nitroimidazole antibiotic resistance protein NimA from Deinococcus radiodurans (DrNimA) is presented. Many anaerobic human pathogenic bacteria are treated using 5-nitroimidazole-based (5-Ni) antibiotics, a class of inactive prodrugs that contain a nitro group. The nitro group must be activated in an anaerobic one-electron reduction and is therefore dependent on the redox system in the target cells. Antibiotic resistance towards 5-Ni drugs is found to be related to the nim genes (nimA, nimB, nimC, nimD, nimE and nimF), which are proposed to encode a reductase that is responsible for converting the nitro group of the antibiotic into a nonbactericidal amine. A mechanism for the Nim enzyme has been proposed in which two-electron reduction of the nitro group leads to the generation of nontoxic derivatives and confers resistance against these antibiotics. The cofactor was found to be important in the mechanism and was found to be covalently linked to the reactive His71. In this paper, the 1.2 Å atomic resolution crystal structure of the 5-nitroimidazole antibiotic resistance protein NimA from Deinococcus radiodurans (DrNimA) is presented. A planar cofactor is clearly visible and well defined in the electron-density map adjacent to His71, the identification of the cofactor and its properties are discussed

  17. Reduction of Fe(III), Cr(VI), U(VI), and Tc(VII) by Deinococcus radiodurans R1

    International Nuclear Information System (INIS)

    Fredrickson, J.K.; Kostandarithes, H.M.; Li, S.W.; Plymake, A.E.; Daly, M.J.

    2000-01-01

    Deinococcus radiodurans is an exceptionally radiation-resistant microorganism capable of surviving acute exposures to ionizing radiation doses of 15,000 Gy and previously described as having a strictly aerobic respiratory metabolism. Under strict anaerobic conditions, D. radiodurans R1 reduced Fe(III)-nitrilotriacetic acid coupled to the oxidation of lactate to CO 2 and acetate but was unable to link this process to growth. D. radiodurans reduced the humic acid analog anthraquinone-2,6-disulfonate (AQDS) to its dihydroquinone form, AH 2 DS, which subsequently transferred electrons to the Fe(III) oxides hydrous ferric oxide and goethite via a previously described electron shuttle mechanism. D. radiodurans reduced the solid-phase Fe(III) oxides in the presence of either 0.1 mM AQDS or leonardite humic acids (2 mg ml -1 ) but not in their absence. D. radiodurans also reduced U(VI) and Tc(VII) in the presence of AQDS. In contrast, Cr(VI) was directly reduced in anaerobic cultures with lactate although the rate of reduction was higher in the presence of AQDS. The results are the first evidence that D. radiodurans can reduce Fe(III) coupled to the oxidation of lactate or other organic compounds. Also, D. radiodurans, in combination with humic acids or synthetic electron shuttle agents, can reduce U and Tc and thus has potential applications for remediation of metal- and radionuclide-contaminated sites where ionizing radiation or other DNA-damaging agents may restrict the activity of more sensitive organisms

  18. Design of Deinococcus radiodurans thioredoxin reductase with altered thioredoxin specificity using computational alanine mutagenesis

    OpenAIRE

    Obiero, Josiah; Sanders, David AR

    2011-01-01

    In this study, the X-ray crystal structure of the complex between Escherichia coli thioredoxin reductase (EC TrxR) and its substrate thioredoxin (Trx) was used as a guide to design a Deinococcus radiodurans TrxR (DR TrxR) mutant with altered Trx specificity. Previous studies have shown that TrxRs have higher affinity for cognate Trxs (same species) than that for Trxs from different species. Computational alanine scanning mutagenesis and visual inspection of the EC TrxR–Trx interface suggested...

  19. Influence of LET on repair of DNA damages in Deinococcus radiodurans

    Energy Technology Data Exchange (ETDEWEB)

    Kobayashi, Y; Tanaka, A; Kikuchi, M; Shimizu, T; Watanabe, H [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment; Cao, J P; Taucher-Scholz, G

    1997-03-01

    Inactivation caused by heavy ions was studied in dry cells of radioresistant bacterium Deinococcus radiodurans. All survival curves were characterized by a large shoulder of the curves. No final slopes of the exponential part of survival curves for heavy ion irradiation were steeper than that for 2.0 MeV electron irradiation. The plots of RBE versus LET showed no obvious peaks, suggesting that this bacterium can repair not only DNA double strand breaks (DSBs) but also clustered damage in DNA which may be induced by heavy ions. The genomic DNA of D. radiodurans was cleaved into large fragments with restriction enzyme Not I after post-irradiation incubation and the fragments were separated using pulsed-field gel electrophoresis (PFGE). DSBs induction and rejoining process were analyzed by detection of the reappearance of ladder pattern of DNA fragments. The required repair time after heavy ions irradiation was longer than the repair time for electrons at the same dose of irradiation, however, the rate of repair enzyme induction was almost similar to each other between electrons and heavy ions, suggesting that the same repair system is likely to be used after both low and high LET irradiations. (author)

  20. Heavy metals-bioremediation by highly radioresistant Deinococcus radiodurans biofilm prospective use in nuclear reactor decontamination

    International Nuclear Information System (INIS)

    Shukla, Sudhir K.; Subba Rao, T.

    2015-01-01

    Over the past few decades, rapid growth of chemical industries have enhanced the heavy metal contamination in water, thereby raising environmental concerns. In the nuclear power industry, decontamination procedure also generates radioactive heavy metal containing wastes. Radio-resistant Deinococcus radiodurans R1 is reported to be a potential candidate for the treatment of low active waste material. To use any bacterium for bioremediation purpose, knowledge about its biofilm production characteristics is a prerequisite. This is because biofilm-mediated bioremediation processes are more efficient as compared to processes mediated by their planktonic counterparts. However, so far there are no reports on the biofilm producing capability of D. radiodurans. We observed that tagging of D. radiodurans by a plasmid harbouring gfp and kan R conferred significant biofilm producing property to the bacterium. Chemical analysis of biofilm matrix components produced by D. radiodurans showed that the matrix consists primarily of proteins and carbohydrates with small amount of extracellular DNA (eDNA). Further, we studied the effect of Ca 2+ on D. radiodurans biofilm formation and it was observed that D. radiodurans biofilm formation was enhanced at higher concentrations of Ca 2+ . We investigated the capability of D. radiodurans biofilm to remove the heavy metals Co and Ni from synthetic waste streams. Results showed that Ca 2+ enhanced the bioremediation of both heavy metals (Co, Ni) by D. radiodurans biofilms in a highly significant manner. In the presence of 50 mM Ca 2+ 35% Co removal and 25% Ni removal was observed, when compared to biofilm grown in the absence of Ca 2+ , which showed mere 7% Co and 3% Ni removal, respectively. The results showed that the presence of Ca 2+ significantly enhanced exopolysaccharide and eDNA (both negatively charged) production in the biofilm matrix. This indicated adsorption could be the major mechanism behind enhanced biofilm mediated removal

  1. Effects of heavy ions on inactivation and DNA double strand breaks in Deinococcus radiodurans R1.

    Science.gov (United States)

    Zimmermann, H; Schafer, M; Schmitz, C; Bucker, H

    1994-10-01

    Inactivation and double strand break (dsb) induction after heavy ion irradiation were studied in stationary phase cells of the highly radiation resistant bacterium Deinococcus radiodurans R1. There is evidence that the radiation sensitivity of this bacterium is nearly independent on energy in the range of up to 15 MeV/u for lighter ions (Ar). The responses to dsb induction for charged particles show direct relationship between increasing radiation dose and residual intact DNA.

  2. in Deinococcus radiodurans

    African Journals Online (AJOL)

    STORAGESEVER

    2010-05-10

    May 10, 2010 ... from oxidation during irradiation (Daly et al., 2007; 2009). According to the first .... radiodurans R1 for bioprecipitation of Uranium from dilute nuclear waste. ... Eide DJ (1998). The molecular biology of metal ion transport in.

  3. Imposed Environmental Stresses Facilitate Cell-Free Nanoparticle Formation by Deinococcus radiodurans.

    Science.gov (United States)

    Chen, Angela; Contreras, Lydia M; Keitz, Benjamin K

    2017-09-15

    The biological synthesis of metal nanoparticles has been examined in a wide range of organisms, due to increased interest in green synthesis and environmental remediation applications involving heavy metal ion contamination. Deinococcus radiodurans is particularly attractive for environmental remediation involving metal reduction, due to its high levels of resistance to radiation and other environmental stresses. However, few studies have thoroughly examined the relationships between environmental stresses and the resulting effects on nanoparticle biosynthesis. In this work, we demonstrate cell-free nanoparticle production and study the effects of metal stressor concentrations and identity, temperature, pH, and oxygenation on the production of extracellular silver nanoparticles by D. radiodurans R1. We also report the synthesis of bimetallic silver and gold nanoparticles following the addition of a metal stressor (silver or gold), highlighting how production of these particles is enabled through the application of environmental stresses. Additionally, we found that both the morphology and size of monometallic and bimetallic nanoparticles were dependent on the environmental stresses imposed on the cells. The nanoparticles produced by D. radiodurans exhibited antimicrobial activity comparable to that of pure silver nanoparticles and displayed catalytic activity comparable to that of pure gold nanoparticles. Overall, we demonstrate that biosynthesized nanoparticle properties can be partially controlled through the tuning of applied environmental stresses, and we provide insight into how their application may affect nanoparticle production in D. radiodurans during bioremediation. IMPORTANCE Biosynthetic production of nanoparticles has recently gained prominence as a solution to rising concerns regarding increased bacterial resistance to antibiotics and a desire for environmentally friendly methods of bioremediation and chemical synthesis. To date, a range of organisms

  4. Gel-based proteomic approach to unravel the extreme radiation resistance of deinococcus radiodurans

    International Nuclear Information System (INIS)

    Basu, Bhakti; Apte, Shree Kumar

    2013-01-01

    The extremophile, Deinococcus radiodurans, is endowed with an extraordinary DNA repair ability and oxidative stress alleviation mechanisms that render it virtually resistant to all types of DNA damaging stressors such as ionizing radiations, UV or years of desiccation. Following DNA damage, the microbe reassembles its complete genome from multiple DNA fragments with impeccable fidelity. The deinococcal genome encodes functional homologues of both prokaryotic and eukaryotic DNA repair pathways, such as RecFOR mediated homologous recombination (HR), nucleotide/base excision repair (NER/BER), strand annealing (SA) and non-homologous end joining (NHEJ), but lacks homologues for universal prokaryotic DNA repair pathways such as RecBCD mediated HR, photo-reactivation and SOS response. It also harbors multiple enzymatic and non-enzymatic oxidative stress defense mechanisms. Proteomic approaches were employed to study the response of D. radiodurans to LD50 dose of gamma irradiation during the post-irradiation growth arrest phase by two dimensional protein electrophoresis coupled with mass spectrometry to reveal kinetics and dynamics of DNA repair, oxidative stress alleviation and resynthesis of damaged proteins, preceding growth recovery

  5. Biosynthesis of gold nanoparticles by the extreme bacterium Deinococcus radiodurans and an evaluation of their antibacterial properties

    Directory of Open Access Journals (Sweden)

    Li J

    2016-11-01

    Full Text Available Jiulong Li,1,* Qinghao Li,1,* Xiaoqiong Ma,2,* Bing Tian,1 Tao Li,1 Jiangliu Yu,1 Shang Dai,1 Yulan Weng,1 Yuejin Hua1 1Key Laboratory for Nuclear-Agricultural Sciences of Chinese Ministry of Agriculture and Zhejiang Province, Institute of Nuclear-Agricultural Sciences, Zhejiang University, 2Central Laboratory, The First Affiliated Hospital of Zhejiang Chinese Medical University, Hangzhou, China *These authors contributed equally to this work Abstract: Deinococcus radiodurans is an extreme bacterium known for its high resistance to stresses including radiation and oxidants. The ability of D. radiodurans to reduce Au(III and biosynthesize gold nanoparticles (AuNPs was investigated in aqueous solution by ultraviolet and visible (UV/Vis absorption spectroscopy, electron microscopy, X-ray diffraction (XRD, dynamic light scattering (DLS, Fourier transform infrared spectroscopy (FTIR and X-ray photoelectron spectroscopy (XPS. D. radiodurans efficiently synthesized AuNPs from 1 mM Au(III solution in 8 h. The AuNPs were of spherical, triangular and irregular shapes with an average size of 43.75 nm and a polydispersity index of 0.23 as measured by DLS. AuNPs were distributed in the cell envelope, across the cytosol and in the extracellular space. XRD analysis confirmed the crystallite nature of the AuNPs from the cell supernatant. Data from the FTIR and XPS showed that upon binding to proteins or compounds through interactions with carboxyl, amine, phospho and hydroxyl groups, Au(III may be reduced to Au(I, and further reduced to Au(0 with the capping groups to stabilize the AuNPs. Biosynthesis of AuNPs was optimized with respect to the initial concentration of gold salt, bacterial growth period, solution pH and temperature. The purified AuNPs exhibited significant antibacterial activity against both Gram-negative (Escherichia coli and Gram-positive (Staphylococcus aureus bacteria by damaging their cytoplasmic membrane. Therefore, the extreme

  6. PprA contributes to Deinococcus radiodurans resistance to nalidixic acid, genome maintenance after DNA damage and interacts with deinococcal topoisomerases.

    Directory of Open Access Journals (Sweden)

    Swathi Kota

    Full Text Available PprA is known to contribute to Deinococcus radiodurans' remarkable capacity to survive a variety of genotoxic assaults. The molecular bases for PprA's role(s in the maintenance of the damaged D. radiodurans genome are incompletely understood, but PprA is thought to promote D. radiodurans's capacity for DSB repair. PprA is found in a multiprotein DNA processing complex along with an ATP type DNA ligase, and the D. radiodurans toposiomerase IB (DraTopoIB as well as other proteins. Here, we show that PprA is a key contributor to D. radiodurans resistance to nalidixic acid (Nal, an inhibitor of topoisomerase II. Growth of wild type D. radiodurans and a pprA mutant were similar in the absence of exogenous genotoxic insults; however, the pprA mutant exhibited marked growth delay and a higher frequency of anucleate cells following treatment with DNA-damaging agents. We show that PprA interacts with both DraTopoIB and the Gyrase A subunit (DraGyrA in vivo and that purified PprA enhances DraTopoIB catalysed relaxation of supercoiled DNA. Thus, besides promoting DNA repair, our findings suggest that PprA also contributes to preserving the integrity of the D. radiodurans genome following DNA damage by interacting with DNA topoisomerases and by facilitating the actions of DraTopoIB.

  7. PprA phosphorylation by STPK of Deinococcus radiodurans changes its in vitro functions

    International Nuclear Information System (INIS)

    Rajpurohit, Yogendra S.; Misra, H.S.

    2011-01-01

    Deinococcus radiodurans shows amazing resistance to both ionizing and non-ionizing radiations. This phenotype is attributed also to its efficient DNA double strand breaks (DSB) repair capability of this bacterium. PprA (pleiotropic protein promoting DNA repair) is unique to D. radiodurans and its role in gamma radiation resistance and DSB repair has been shown in this bacterium. Recombinant PrA protects dsDNA from exonuclease degradation and stimulates the DNA ends joining activity of both T4 DNA ligase and E.coli NAD ligase in vitro. Phosphomotif search showed that PprA has putative phosphorylation site similar to that is characterized for Ser/Thr protein kinases in eukaryotic system. A eukaryotic type Ser/Thr protein kinase (DR2518) of D. radiodurans, could phosphorylate recombinant PprA at Thr amino acid in vitro and the phosphorylation of PprA was also observed in vivo. DR2518 kinase mediated protein phosphorylation of PprA, improves its DNA binding affinity by nearly four fold and stimulated T4 DNA ligase activity more towards intermolecular ligation, as compared to unphosphorylated PprA. Interestingly, the phospho-PprA showed lesser protection of dsDNA than unphospho-PprA when incubated with exonuclease III in solution. The putative Thr of PprA was replaced with Ala (T48A) by site directed mutagenesis, which resulted in significant reduction of PprA phosphorylation by DR2518 kinase. Detailed studies on PprA phosphorylation and its functional significance would be presented. (author)

  8. A PerR-like protein involved in response to oxidative stress in the extreme bacterium Deinococcus radiodurans

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Chengzhi; Wang, Liangyan; Li, Tao; Lin, Lin; Dai, Shang; Tian, Bing, E-mail: tianbing@zju.edu.cn; Hua, Yuejin, E-mail: yjhua@zju.edu.cn

    2014-07-18

    Highlights: • We report a novel PerR-like protein of Fur family in D. radiodurans that is not annotated in the current database. • drperR responses to H{sub 2}O{sub 2} and functions as a negative regulator of katE and dps. • We provided implications on how to utilize sequenced genome data and the importance of genome data mining. • This study adds knowledge to complicated regulatory network that responds to ROS stress in D. radiodurans. - Abstract: Response and defense systems against reactive oxygen species (ROS) contribute to the remarkable resistance of Deinococcus radiodurans to oxidative stress induced by oxidants or radiation. However, mechanisms involved in ROS response and defense systems of D. radiodurans are not well understood. Fur family proteins are important in ROS response. Only a single Fur homolog is predicted by sequence similarity in the current D. radiodurans genome database. Our bioinformatics analysis demonstrated an additional guanine nucleotide in the genome of D. radiodurans that is not in the database, leading to the discovery of another Fur homolog DrPerR. Gene disruption mutant of DrPerR showed enhanced resistance to hydrogen peroxide (H{sub 2}O{sub 2}) and increased catalase activity in cell extracts. Real-time PCR results indicated that DrPerR functions as a repressor of the catalase gene katE. Meanwhile, derepression of dps (DNA-binding proteins from starved cells) gene under H{sub 2}O{sub 2} stress by DrPerR point to its regulatory role in metal ions hemostasis. Thus, DrPerR might function as a Fur homolog protein which is involved in ROS response and defense. These results help clarify the complicated regulatory network that responds to ROS stress in D. radiodurans.

  9. A PerR-like protein involved in response to oxidative stress in the extreme bacterium Deinococcus radiodurans

    International Nuclear Information System (INIS)

    Liu, Chengzhi; Wang, Liangyan; Li, Tao; Lin, Lin; Dai, Shang; Tian, Bing; Hua, Yuejin

    2014-01-01

    Highlights: • We report a novel PerR-like protein of Fur family in D. radiodurans that is not annotated in the current database. • drperR responses to H 2 O 2 and functions as a negative regulator of katE and dps. • We provided implications on how to utilize sequenced genome data and the importance of genome data mining. • This study adds knowledge to complicated regulatory network that responds to ROS stress in D. radiodurans. - Abstract: Response and defense systems against reactive oxygen species (ROS) contribute to the remarkable resistance of Deinococcus radiodurans to oxidative stress induced by oxidants or radiation. However, mechanisms involved in ROS response and defense systems of D. radiodurans are not well understood. Fur family proteins are important in ROS response. Only a single Fur homolog is predicted by sequence similarity in the current D. radiodurans genome database. Our bioinformatics analysis demonstrated an additional guanine nucleotide in the genome of D. radiodurans that is not in the database, leading to the discovery of another Fur homolog DrPerR. Gene disruption mutant of DrPerR showed enhanced resistance to hydrogen peroxide (H 2 O 2 ) and increased catalase activity in cell extracts. Real-time PCR results indicated that DrPerR functions as a repressor of the catalase gene katE. Meanwhile, derepression of dps (DNA-binding proteins from starved cells) gene under H 2 O 2 stress by DrPerR point to its regulatory role in metal ions hemostasis. Thus, DrPerR might function as a Fur homolog protein which is involved in ROS response and defense. These results help clarify the complicated regulatory network that responds to ROS stress in D. radiodurans

  10. Regulation of MntH by a dual Mn(II- and Fe(II-dependent transcriptional repressor (DR2539 in Deinococcus radiodurans.

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    Hongxing Sun

    Full Text Available The high intracellular Mn/Fe ratio observed within the bacteria Deinococcus radiodurans may contribute to its remarkable resistance to environmental stresses. We isolated DR2539, a novel regulator of intracellular Mn/Fe homeostasis in D. radiodurans. Electrophoretic gel mobility shift assays (EMSAs revealed that DR2539 binds specifically to the promoter of the manganese acquisition transporter (MntH gene, and that DR0865, the only Fur homologue in D. radiodurans, cannot bind to the promoter of mntH, but it can bind to the promoter of another manganese acquisition transporter, MntABC. β-galactosidase expression analysis indicated that DR2539 acts as a manganese- and iron-dependent transcriptional repressor. Further sequence alignment analysis revealed that DR2539 has evolved some special characteristics. Site-directed mutagenesis suggested that His98 plays an important role in the activities of DR2539, and further protein-DNA binding activity assays showed that the activity of H98Y mutants decreased dramatically relative to wild type DR2539. Our study suggests that D. radiodurans has evolved a very efficient manganese regulation mechanism that involves its high intracellular Mn/Fe ratio and permits resistance to extreme conditions.

  11. DR2539 is a novel DtxR-like regulator of Mn/Fe ion homeostasis and antioxidant enzyme in Deinococcus radiodurans

    International Nuclear Information System (INIS)

    Chen, Huan; Wu, Rongrong; Xu, Guangzhi; Fang, Xu; Qiu, Xiaoli; Guo, Hongyin; Tian, Bing; Hua, Yuejin

    2010-01-01

    Transcriptional regulators of the diphtheria toxin repressor (DtxR) family control the expression of genes involved in the uptake of iron and manganese, which is not only necessitous nutrients but also was suggested to be essential for intracellular redox cycling of microorganisms. We identified a unique DtxR homologue (DR2539) with special characteristics from Deinococcus radiodurans, which is known for its extreme resistance to radiation and oxidants. The dr2539 mutant showed higher resistance to hydrogen peroxide than the wild-type strain R1. Intracellular catalase activity assay and semiquantitative PCR analysis demonstrated that this DtxR is a negative regulator of catalase (katE). Furthermore, quantitative real-time PCR, global transcription profile and inductively coupled plasma-mass spectrometry analysis showed that the DtxR is involved in the regulation of antioxidant system by maintaining the intracellular Mn/Fe ion homeostasis of D. radiodurans. However, unlike the other DtxR homologues, the DtxR of D. radiodurans acts as a negative regulator of a Mn transporter gene (dr2283) and as a positive regulator of Fe-dependent transporter genes (dr1219, drb0125) in D. radiodurans.

  12. DR2539 is a novel DtxR-like regulator of Mn/Fe ion homeostasis and antioxidant enzyme in Deinococcus radiodurans

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Huan [Key Laboratory for Nuclear-Agricultural Sciences of Chinese Ministry of Agriculture and Zhejiang Province, Institute of Nuclear-Agricultural Sciences, Zhejiang University, Hangzhou 310029 (China); Zhejiang Institute of Microbiology, Zhejiang Province, Hangzhou 310012 (China); Wu, Rongrong [Department of Cardiology, Second Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou 310009 (China); Xu, Guangzhi [Key Laboratory for Nuclear-Agricultural Sciences of Chinese Ministry of Agriculture and Zhejiang Province, Institute of Nuclear-Agricultural Sciences, Zhejiang University, Hangzhou 310029 (China); Fang, Xu; Qiu, Xiaoli; Guo, Hongyin [Zhejiang Institute of Microbiology, Zhejiang Province, Hangzhou 310012 (China); Tian, Bing, E-mail: tianbing@zju.edu.cn [Key Laboratory for Nuclear-Agricultural Sciences of Chinese Ministry of Agriculture and Zhejiang Province, Institute of Nuclear-Agricultural Sciences, Zhejiang University, Hangzhou 310029 (China); Hua, Yuejin, E-mail: yjhua@zju.edu.cn [Key Laboratory for Nuclear-Agricultural Sciences of Chinese Ministry of Agriculture and Zhejiang Province, Institute of Nuclear-Agricultural Sciences, Zhejiang University, Hangzhou 310029 (China)

    2010-05-28

    Transcriptional regulators of the diphtheria toxin repressor (DtxR) family control the expression of genes involved in the uptake of iron and manganese, which is not only necessitous nutrients but also was suggested to be essential for intracellular redox cycling of microorganisms. We identified a unique DtxR homologue (DR2539) with special characteristics from Deinococcus radiodurans, which is known for its extreme resistance to radiation and oxidants. The dr2539 mutant showed higher resistance to hydrogen peroxide than the wild-type strain R1. Intracellular catalase activity assay and semiquantitative PCR analysis demonstrated that this DtxR is a negative regulator of catalase (katE). Furthermore, quantitative real-time PCR, global transcription profile and inductively coupled plasma-mass spectrometry analysis showed that the DtxR is involved in the regulation of antioxidant system by maintaining the intracellular Mn/Fe ion homeostasis of D. radiodurans. However, unlike the other DtxR homologues, the DtxR of D. radiodurans acts as a negative regulator of a Mn transporter gene (dr2283) and as a positive regulator of Fe-dependent transporter genes (dr1219, drb0125) in D. radiodurans.

  13. Involvement of recQ in the ultraviolet damage repair pathway in Deinococcus radiodurans

    International Nuclear Information System (INIS)

    Hua Xiaoting; Huang Lifen; Tian Bing; Hua Yuejin

    2008-01-01

    Deinococcus radiodurans is a bacterium which can survive extremely DNA damage. To investigate the relationship between recQ and the ultraviolet radiation (UV) damage repair pathway, we created a four mutant strain by constructing recQ knockout mutants in uvrA1, uvrA2, and uvsE backgrounds. Using the rpoB/Rif r system, we measured the mutation frequencies and rates in wild type, recQ (MQ), uvsE uvrA1 uvrA2 (TNK006), and uvsE uvrA1 uvrA2 recQ (TQ). We then isolated Rif r mutants of these strains and sequenced the rpoB gene. The mutation frequency of TQ was 6.4, 10.1, and 2.43 times that of wild type, MQ, and TNK006, respectively, and resulted in rates of 4.7, 6.71, and 2.15 folds higher than that of wild type, MQ, and TNK006, respectively. All the strains demonstrated specific mutational hotspots. Furthermore, the TQ strain showed a transversion bias that was different from the other three strains. The results indicate that recQ is involved in the ultraviolet damage repair pathway via the interaction between recQ and uvrA1, uvrA2, and uvsE in D. radiodurans

  14. Deinococcus antarcticus sp. nov., isolated from soil.

    Science.gov (United States)

    Dong, Ning; Li, Hui-Rong; Yuan, Meng; Zhang, Xiao-Hua; Yu, Yong

    2015-02-01

    A pink-pigmented, non-motile, coccoid bacterial strain, designated G3-6-20(T), was isolated from a soil sample collected in the Grove Mountains, East Antarctica. This strain was resistant to UV irradiation (810 J m(-2)) and slightly more sensitive to desiccation as compared with Deinococcus radiodurans. Phylogenetic analyses based on the 16S rRNA gene sequence of the isolate indicated that the organism belongs to the genus Deinococcus. Highest sequence similarities were with Deinococcus ficus CC-FR2-10(T) (93.5 %), Deinococcus xinjiangensis X-82(T) (92.8 %), Deinococcus indicus Wt/1a(T) (92.5 %), Deinococcus daejeonensis MJ27(T) (92.3 %), Deinococcus wulumuqiensis R-12(T) (92.3 %), Deinococcus aquaticus PB314(T) (92.2 %) and Deinococcus radiodurans DSM 20539(T) (92.2 %). Major fatty acids were C18 : 1ω7c, summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c), anteiso-C15 : 0 and C16 : 0. The G+C content of the genomic DNA of strain G3-6-20(T) was 63.1 mol%. Menaquinone 8 (MK-8) was the predominant respiratory quinone. Based on its phylogenetic position, and chemotaxonomic and phenotypic characteristics, strain G3-6-20(T) represents a novel species of the genus Deinococcus, for which the name Deinococcus antarcticus sp. nov. is proposed. The type strain is G3-6-20(T) ( = DSM 27864(T) = CCTCC AB 2013263(T)). © 2015 IUMS.

  15. Conservation of the LexA repressor binding site in Deinococcus radiodurans

    Directory of Open Access Journals (Sweden)

    Khan Feroz

    2008-03-01

    Full Text Available The LexA protein is a transcriptional repressor of the bacterial SOS DNA repair system, which comprises a set of DNA repair and cellular survival genes that are induced in response to DNA damage. Its varied DNA binding motifs have been characterized and reported in the Escherichia coli, Bacillus subtilis, rhizobia family members, marine magnetotactic bacterium, Salmonella typhimurium and recently in Mycobacterium tuberculosis and this motifs information has been used in our theoretical analysis to detect its novel regulated genes in radio-resistant Deinococcus radiodurans genome. This bacterium showed presence of SOS-box like consensus sequence in the upstream sequences of 3166 genes with >60% motif score similarity percentage (MSSP on both strands. Attempts to identify LexA-binding sites and the composition of the putative SOS regulon in D. radiodurans have been unsuccessful so far. To resolve the problem we performed theoretical analysis with modifications on reported data set of genes related to DNA repair (61 genes, stress response (145 genes and some unusual predicted operons (21 clusters. Expression of some of the predicted SOS-box regulated operon members then was examined through the previously reported microarray data which confirm the expression of only single predicted operon i.e. DRB0143 (AAA superfamily NTPase related to 5-methylcytosine specific restriction enzyme subunit McrB and DRB0144 (homolog of the McrC subunit of the McrBC restriction modification system. The methodology involved weight matrix construction through CONSENSUS algorithm using information of conserved upstream sequences of eight known genes including dinB, tagC, lexA, recA, uvrB, yneA of B. subtilis while lexA and recA of D. radiodurans through phylogenetic footprinting method and later detection of similar conserved SOS-box like LexA binding motifs through both RSAT & PoSSuMsearch programs. The resultant DNA consensus sequence had highly conserved 14 bp SOS

  16. Whole cell Deinococcus radiodurans ameliorates salt stress in Indian mustard through pyrroloquinoline quinone

    International Nuclear Information System (INIS)

    Srivastava, A.K.; Jadhav, P.; Suprasanna, P.; Rajpurohit, Y.S.; Misra, H.S.

    2015-01-01

    Salinity stress is considered as one of the major abiotic stresses limiting crop productivity. A variety of symbiotic and non-symbiotic bacteria are currently being used worldwide with the aim to boost built-in defense system in plants. Deinococcus radiodurans is a highly desiccation and radiation tolerant bacterium which synthesizes PQQ (pyrroloquinoline quinone) that has been shown to have a versatile role in crop productivity and as a general stress response regulator in bacteria and mammals. PQQ also acts as scavenger of reactive oxygen species and hence, can module redox signaling, one of the major regulator of stress tolerance in plants. In view of this, present research was conducted to evaluate the potential of whole cell D. radiodurans for ameliorating salt stress in plants. The soil colonization with wild-type cells led to partial amelioration of salt stress. The PQQ mutant showed an intermediate phenotype between wild-type seedlings and those grown on non-colonized soils which confirmed that the effects are largely associated with PQQ. The differential phenotype was also correlated with ROS level and ABA accumulation. The flame photometry data showed that there was no significant reduction in water soluble Na + level in control plant and those treated with either wild-type or PQQ mutant. Further, the elevated levels of antioxidant enzymes and reduced ascorbate in the plants treated with bacterial cells indicated its positive role in oxidative stress management. Although, the exact molecular basis to these effects is yet to be understood, present findings support the use of whole cell D. radiodurans for managing the growth and productivity of Indian mustard in salt affected fields. (author)

  17. The essential role of the Deinococcus radiodurans ssb gene in cell survival and radiation tolerance.

    Directory of Open Access Journals (Sweden)

    J Scott Lockhart

    Full Text Available Recent evidence has implicated single-stranded DNA-binding protein (SSB expression level as an important factor in microbial radiation resistance. The genome of the extremely radiation resistant bacterium Deinococcus radiodurans contains genes for two SSB homologs: the homodimeric, canonical Ssb, encoded by the gene ssb, and a novel pentameric protein encoded by the gene ddrB. ddrB is highly induced upon exposure to radiation, and deletions result in decreased radiation-resistance, suggesting an integral role of the protein in the extreme resistance exhibited by this organism. Although expression of ssb is also induced after irradiation, Ssb is thought to be involved primarily in replication. In this study, we demonstrate that Ssb in D. radiodurans is essential for cell survival. The lethality of an ssb deletion cannot be complemented by providing ddrB in trans. In addition, the radiation-sensitive phenotype conferred by a ddrB deletion is not alleviated by providing ssb in trans. By altering expression of the ssb gene, we also show that lower levels of transcription are required for optimal growth than are necessary for high radiation resistance. When expression is reduced to that of E. coli, ionizing radiation resistance is similarly reduced. UV resistance is also decreased under low ssb transcript levels where growth is unimpaired. These results indicate that the expression of ssb is a key component of both normal cellular metabolism as well as pathways responsible for the high radiation tolerance of D. radiodurans.

  18. Laboratory simulation of interplanetary ultraviolet radiation (broad spectrum) and its effects on Deinococcus radiodurans

    Science.gov (United States)

    Paulino-Lima, Ivan Gláucio; Pilling, Sérgio; Janot-Pacheco, Eduardo; de Brito, Arnaldo Naves; Barbosa, João Alexandre Ribeiro Gonçalves; Leitão, Alvaro Costa; Lage, Claudia de Alencar Santos

    2010-08-01

    The radiation-resistant bacterium Deinococcus radiodurans was exposed to a simulated interplanetary UV radiation at the Brazilian Synchrotron Light Laboratory (LNLS). Bacterial samples were irradiated on different substrates to investigate the influence of surface relief on cell survival. The effects of cell multi-layers were also investigated. The ratio of viable microorganisms remained virtually the same (average 2%) for integrated doses from 1.2 to 12 kJ m -2, corresponding to 16 h of irradiation at most. The asymptotic profiles of the curves, clearly connected to a shielding effect provided by multi-layering cells on a cavitary substrate (carbon tape), means that the inactivation rate may not change significantly along extended periods of exposure to radiation. Such high survival rates reinforce the possibility of an interplanetary transfer of viable microbes.

  19. Extremely radioresistant microbe Deinococcus radiodurans does not survive tellurite-mediated oxidative stress: revelation of molecular basis

    International Nuclear Information System (INIS)

    Apte, Shree Kumar; Narasimha, Anaganti; Basu, Bhakti

    2014-01-01

    Deinococcus radiodurans exhibits extraordinary resistance to gamma radiation as well as oxidative stress. Comparison of tellurite stress with gamma irradiation, both of which impart severe oxidative stress, revealed that tellurite induced less ROS and caused less oxidative damage to proteins, but was much more lethal to D. radiodurans than gamma irradiation. The proteomic changes induced by tellurite exposure were mapped by two dimensional protein electrophoresis followed by mass spectrometry. Seventy proteins belonging to major functional categories of oxidative stress alleviation, protein translation/folding and metabolism were identified. Tellurite responsive proteome dynamics displayed (i) up-regulation of proteins involved in tellurite stress resistance and oxidative stress alleviation, dehydrogenases involved in generation of reducing potential, and chaperones (such DnaK), and (ii) down regulation of key glycolysis and TCA cycle enzymes, proteins involved in protein translation/folding and energy production. Tellurite stress also resulted in nearly 50% loss in the cellular reducing potential within 1h of exposure while gamma irradiation had no such effect. The findings provide a better insight into the mechanism of tellurite toxicity, beyond metal mediated oxidative stress, in this extremophile. (author)

  20. Biosynthesis of gold nanoparticles by the extreme bacterium Deinococcus radiodurans and an evaluation of their antibacterial properties.

    Science.gov (United States)

    Li, Jiulong; Li, Qinghao; Ma, Xiaoqiong; Tian, Bing; Li, Tao; Yu, Jiangliu; Dai, Shang; Weng, Yulan; Hua, Yuejin

    Deinococcus radiodurans is an extreme bacterium known for its high resistance to stresses including radiation and oxidants. The ability of D. radiodurans to reduce Au(III) and biosynthesize gold nanoparticles (AuNPs) was investigated in aqueous solution by ultraviolet and visible (UV/Vis) absorption spectroscopy, electron microscopy, X-ray diffraction (XRD), dynamic light scattering (DLS), Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS). D. radiodurans efficiently synthesized AuNPs from 1 mM Au(III) solution in 8 h. The AuNPs were of spherical, triangular and irregular shapes with an average size of 43.75 nm and a polydispersity index of 0.23 as measured by DLS. AuNPs were distributed in the cell envelope, across the cytosol and in the extracellular space. XRD analysis confirmed the crystallite nature of the AuNPs from the cell supernatant. Data from the FTIR and XPS showed that upon binding to proteins or compounds through interactions with carboxyl, amine, phospho and hydroxyl groups, Au(III) may be reduced to Au(I), and further reduced to Au(0) with the capping groups to stabilize the AuNPs. Biosynthesis of AuNPs was optimized with respect to the initial concentration of gold salt, bacterial growth period, solution pH and temperature. The purified AuNPs exhibited significant antibacterial activity against both Gram-negative ( Escherichia coli ) and Gram-positive ( Staphylococcus aureus ) bacteria by damaging their cytoplasmic membrane. Therefore, the extreme bacterium D. radiodurans can be used as a novel bacterial candidate for efficient biosynthesis of AuNPs, which exhibited potential in biomedical application as an antibacterial agent.

  1. Effect of N+ beam exposure on superoxide dismutase and catalase activities and induction of Mn-SOD in Deinococcus radiodurans

    International Nuclear Information System (INIS)

    Song Daojun; Chen Ruolei; Shao Chunlin; Wu Lijun; Yu Zengliang

    2000-01-01

    Though bacteria of the radiation-resistant Deinococcus radiodurans have a high resistance to the lethal and mutagenic effects of many DNA-damaging agents, the mechanisms involved in the response of these bacteria to oxidative stress are poorly understood. The superoxide dismutase (SOD) and catalase (CAT) activities produced by these bacteria were measured, and the change of SOD and CAT activities by 20 keV N + beam exposure was examined. Their activities were increased by N + beam exposure from 8 x 10 14 ions/cm 2 to 6 x 10 15 ions/cm 2 . The treatment of H 2 O 2 and [CHCl 3 + CH 3 CH 2 OH] and the measurement of absorption spectrum showed that the increase in SOD activity was resulted from inducible activities of Mn-SOD in D. radiodurans AS1.633 by N + beam exposure. These results suggested that this bacteria possess inducible defense mechanisms against the deleterious effects of oxidisation

  2. Characterizing the Catalytic Potential of Deinococcus, Arthrobacter and other Robust Bacteria in Contaminated Subsurface Environments of the Hanford Site

    Energy Technology Data Exchange (ETDEWEB)

    Daly, Michael J.

    2007-07-23

    Progress is briefly summarized in these areas: ionizing radiation resistance in bacteria; a hypothesis regarding ionizing radiation resistance emerging for bacterial cells; transcriptome analysis of irradiated D. radiodurans and Shewanella oneidensis; the role of metal reduction in Mn-dependnet Deinococcal species; and engineered Deinococcus strains as models for bioremediation. Key findings are also reported regarding protein oxidation as a possible key to bacterial desiccation resistance, and the whole-genome sequence of the thermophile Deinococcus geothermalis.

  3. FtsZ from radiation resistant bacterium Deinococcus radiodurans is different from its characterized homologues

    International Nuclear Information System (INIS)

    Mehta, Kruti P.; Misra, H.S.

    2012-01-01

    Polymerization/depolymerization dynamics of FtsZ and its GTPase activity are interdependent and the regulation of these processes determines the growth rate in a bacterium. Deinococcus radiodurans R1 that is best known for its extraordinary radiation resistance and efficient DNA double strand break repair is a comparatively slow growing bacterium and its growth gets arrested in response to gamma radiation. Mechanisms of cell division and its regulation under gamma stressed growth condition would be worth investigating. Genome of this bacterium encodes at least all the known components of divisome. Recombinant FtsZ of D. radiodurans (drFtsZ) preferred Mg 2+ for its GTPase activity. Relatively a very low GTPase activity was observed in presence of Mn 2+ , Co 2+ and Ni 2+ while release of inorganic phosphate could not be detected in presence of other divalent ions including Ca 2+ . GTPase activity of drFtsZ was lower than E. coli but higher than Mycobacterium and it required both Mg 2+ and GTP for its polymerization. Its GTPase activity did not increase with increasing concentration of Mg 2+ and correlates with the bundling of protofilaments. Results obtained from transmission electron microscopy and sedimentation analysis supported the reciprocal correlation of polymerization/depolymerization with the levels of GTPase activity. Dynamic light scattering in presence of 5mM or higher concentration of Mg 2+ and Mn 2 showed a characteristic cyclic change in light scattering without addition of extra metal ion or GTP

  4. Effects of Low-Temperature Plasma-Sterilization on Mars Analog Soil Samples Mixed with Deinococcus radiodurans

    Directory of Open Access Journals (Sweden)

    Janosch Schirmack

    2016-05-01

    Full Text Available We used Ar plasma-sterilization at a temperature below 80 °C to examine its effects on the viability of microorganisms when intermixed with tested soil. Due to a relatively low temperature, this method is not thought to affect the properties of a soil, particularly its organic component, to a significant degree. The method has previously been shown to work well on spacecraft parts. The selected microorganism for this test was Deinococcus radiodurans R1, which is known for its remarkable resistance to radiation effects. Our results showed a reduction in microbial counts after applying a low temperature plasma, but not to a degree suitable for a sterilization of the soil. Even an increase of the treatment duration from 1.5 to 45 min did not achieve satisfying results, but only resulted in in a mean cell reduction rate of 75% compared to the untreated control samples.

  5. PprM is necessary for up-regulation of katE1, encoding the major catalase of Deinococcus radiodurans, under unstressed culture conditions.

    Science.gov (United States)

    Jeong, Sun-Wook; Seo, Ho Seong; Kim, Min-Kyu; Choi, Jong-Il; Lim, Heon-Man; Lim, Sangyong

    2016-06-01

    Deinococcus radiodurans is a poly-extremophilic organism, capable of tolerating a wide variety of different stresses, such as gamma/ultraviolet radiation, desiccation, and oxidative stress. PprM, a cold shock protein homolog, is involved in the radiation resistance of D. radiodurans, but its role in the oxidative stress response has not been investigated. In this study, we investigated the effect of pprM mutation on catalase gene expression. pprM disruption decreased the mRNA and protein levels of KatE1, which is the major catalase in D. radiodurans, under normal culture conditions. A pprM mutant strain (pprM MT) exhibited decreased catalase activity, and its resistance to hydrogen peroxide (H2O2) decreased accordingly compared with that of the wild-type strain. We confirmed that RecG helicase negatively regulates katE1 under normal culture conditions. Among katE1 transcriptional regulators, the positive regulator drRRA was not altered in pprM (-), while the negative regulators perR, dtxR, and recG were activated more than 2.5-fold in pprM MT. These findings suggest that PprM is necessary for KatE1 production under normal culture conditions by down-regulation of katE1 negative regulators.

  6. Regulation of potassium dependent ATPase (kdp) operon of Deinococcus radiodurans.

    Science.gov (United States)

    Dani, Pratiksha; Ujaoney, Aman Kumar; Apte, Shree Kumar; Basu, Bhakti

    2017-01-01

    The genome of D. radiodurans harbors genes for structural and regulatory proteins of Kdp ATPase, in an operon pattern, on Mega plasmid 1. Organization of its two-component regulatory genes is unique. Here we demonstrate that both, the structural as well as regulatory components of the kdp operon of D. radiodurans are expressed quickly as the cells experience potassium limitation but are not expressed upon increase in osmolarity. The cognate DNA binding response regulator (RR) effects the expression of kdp operon during potassium deficiency through specific interaction with the kdp promoter. Deletion of the gene encoding RR protein renders the mutant D. radiodurans (ΔRR) unable to express kdp operon under potassium limitation. The ΔRR D. radiodurans displays no growth defect when grown on rich media or when exposed to oxidative or heat stress but shows reduced growth following gamma irradiation. The study elucidates the functional and regulatory aspects of the novel kdp operon of this extremophile, for the first time.

  7. Method for detecting DNA strand breaks in mammalian cells using the Deinococcus radiodurans PprA protein

    International Nuclear Information System (INIS)

    Satoh, Katsuya; Wada, Seiichi; Kikuchi, Masahiro; Funayama, Tomoo; Narumi, Issay; Kobayashi, Yasuhiko

    2006-01-01

    In a previous study, we identified the novel protein PprA that plays a critical role in the radiation resistance of Deinococcus radiodurans. In this study, we focussed on the ability of PprA protein to recognize and bind to double-stranded DNA carrying strand breaks, and attempted to visualize radiation-induced DNA strand breaks in mammalian cultured cells by employing PprA protein using an immunofluorescence technique. Increased PprA protein binding to CHO-K1 nuclei immediately following irradiation suggests the protein is binding to DNA strand breaks. By altering the cell permeabilization conditions, PprA protein binding to CHO-K1 mitochondria, which is probably resulted from DNA strand break immediately following irradiation, was also detected. The method developed and detailed in this study will be useful in evaluating DNA damage responses in cultured cells, and could also be applicable to genotoxic tests in the environmental and pharmaceutical fields

  8. Comparative proteomics reveals key proteins recruited at the nucleoid of Deinococcus after irradiation-induced DNA damage

    International Nuclear Information System (INIS)

    Bouthier de la Tour, Claire; Passot, Fanny Marie; Toueille, Magali; Servant, Pascale; Sommer, Suzanne; Mirabella, Boris; Blanchard, Laurence; Groot, Arjan de; Guerin, Philippe; Armengaud, Jean

    2013-01-01

    The nucleoids of radiation-resistant Deinococcus species show a high degree of compaction maintained after ionizing irradiation. We identified proteins recruited after irradiation in nucleoids of Deinococcus radiodurans and Deinococcus deserti by means of comparative proteomics. Proteins in nucleoid-enriched fractions from unirradiated and irradiated Deinococcus were identified and semi quantified by shotgun proteomics. The ssDNA-binding protein SSB, DNA gyrase subunits GyrA and GyrB, DNA topoisomerase I, RecA recombinase, UvrA excinuclease, RecQ helicase, DdrA, DdrB, and DdrD proteins were found in significantly higher amounts in irradiated nucleoids of both Deinococcus species. We observed, by immunofluorescence microscopy, the subcellular localization of these proteins in D. radiodurans, showing for the first time the recruitment of the DdrD protein into the D. radiodurans nucleoid. We specifically followed the kinetics of recruitment of RecA, DdrA, and DdrD to the nucleoid after irradiation. Remarkably, RecA proteins formed irregular filament-like structures 1 h after irradiation, before being redistributed throughout the cells by 3 h post-irradiation. Comparable dynamics of DdrD localization were observed, suggesting a possible functional interaction between RecA and DdrD. Several proteins involved in nucleotide synthesis were also seen in higher quantities in the nucleoids of irradiated cells, indicative of the existence of a mechanism for orchestrating the presence of proteins involved in DNA metabolism in nucleoids in response to massive DNA damage. All MS data have been deposited in the ProteomeXchange with identifier PXD00196. (authors)

  9. Stress induction in the bacteria Shewanella oneidensis and Deinococcus radiodurans in response to below-background ionizing radiation.

    Science.gov (United States)

    Castillo, Hugo; Schoderbek, Donald; Dulal, Santosh; Escobar, Gabriela; Wood, Jeffrey; Nelson, Roger; Smith, Geoffrey

    2015-01-01

    The 'Linear no-threshold' (LNT) model predicts that any amount of radiation increases the risk of organisms to accumulate negative effects. Several studies at below background radiation levels (4.5-11.4 nGy h(-1)) show decreased growth rates and an increased susceptibility to oxidative stress. The purpose of our study is to obtain molecular evidence of a stress response in Shewanella oneidensis and Deinococcus radiodurans grown at a gamma dose rate of 0.16 nGy h(-1), about 400 times less than normal background radiation. Bacteria cultures were grown at a dose rate of 0.16 or 71.3 nGy h(-1) gamma irradiation. Total RNA was extracted from samples at early-exponential and stationary phases for the rt-PCR relative quantification (radiation-deprived treatment/background radiation control) of the stress-related genes katB (catalase), recA (recombinase), oxyR (oxidative stress transcriptional regulator), lexA (SOS regulon transcriptional repressor), dnaK (heat shock protein 70) and SOA0154 (putative heavy metal efflux pump). Deprivation of normal levels of radiation caused a reduction in growth of both bacterial species, accompanied by the upregulation of katB, recA, SOA0154 genes in S. oneidensis and the upregulation of dnaK in D. radiodurans. When cells were returned to background radiation levels, growth rates recovered and the stress response dissipated. Our results indicate that below-background levels of radiation inhibited growth and elicited a stress response in two species of bacteria, contrary to the LNT model prediction.

  10. Cyclic AMP Receptor Protein Acts as a Transcription Regulator in Response to Stresses in Deinococcus radiodurans.

    Directory of Open Access Journals (Sweden)

    Su Yang

    Full Text Available The cyclic AMP receptor protein family of transcription factors regulates various metabolic pathways in bacteria, and also play roles in response to environmental changes. Here, we identify four homologs of the CRP family in Deinococcus radiodurans, one of which tolerates extremely high levels of oxidative stress and DNA-damaging reagents. Transcriptional levels of CRP were increased under hydrogen peroxide (H2O2 treatment during the stationary growth phase, indicating that CRPs function in response to oxidative stress. By constructing all CRP single knockout mutants, we found that the dr0997 mutant showed the lowest tolerance toward H2O2, ultraviolet radiation, ionizing radiation, and mitomycin C, while the phenotypes of the dr2362, dr0834, and dr1646 mutants showed slight or no significant differences from those of the wild-type strain. Taking advantage of the conservation of the CRP-binding site in many bacteria, we found that transcription of 18 genes, including genes encoding chromosome-partitioning protein (dr0998, Lon proteases (dr0349 and dr1974, NADH-quinone oxidoreductase (dr1506, thiosulfate sulfurtransferase (dr2531, the DNA repair protein UvsE (dr1819, PprA (dra0346, and RecN (dr1447, are directly regulated by DR0997. Quantitative real-time polymerase chain reaction (qRT-PCR analyses showed that certain genes involved in anti-oxidative responses, DNA repair, and various cellular pathways are transcriptionally attenuated in the dr0997 mutant. Interestingly, DR0997 also regulate the transcriptional levels of all CRP genes in this bacterium. These data suggest that DR0997 contributes to the extreme stress resistance of D. radiodurans via its regulatory role in multiple cellular pathways, such as anti-oxidation and DNA repair pathways.

  11. Deinococcus frigens sp. nov., Deinococcus saxicola sp. nov., and Deinococcus marmoris sp. nov., low temperature and draught-tolerating, UV-resistant bacteria from continental Antarctica.

    Science.gov (United States)

    Hirsch, Peter; Gallikowski, Claudia A; Siebert, Jörg; Peissl, Klaus; Kroppenstedt, Reiner; Schumann, Peter; Stackebrandt, Erko; Anderson, Robert

    2004-11-01

    Six Gram-positive, non-motile, UV- and draught-tolerant bacteria were isolated from antarctic soil and rock samples. The pink to orange cocci grew well on oligotrophic medium PYGV (pH 7.5) at 9-18 degrees C. They tolerated 0-10% NaCl, were aerobic to facultatively anaerobic and contained ornithine in their cell wall (type A3beta, Orn-Gly2). The lipid profiles of four strains were found to be typical for those of D. radiodurans. Major fatty acids were 16:1cis9, 15:1cis9, 17:1cis9 and i17:1cis9, the respiratory quinone of three strains was MK-8. Comparative 16S rDNA gene sequencing revealed phylogenetic relationships to the Deinococcus clade, especially to D. radiopugnans. The levels of 16S rRNA gene sequence similarity and DNA-DNA hybridisation data showed the six isolates represented new taxa. Phenotypic properties supported the description of three new species which were different from the eight known Deinococcus species and particularly from D. radiopugnans. Soil isolate AA-692T (DSM 12807T) is the type strain of Deinococcus frigens sp. nov., with AA-752 (DSM 15993) and AA-829 (DSM 15994) as additional strains from soil. The endolithic isolate AA-1444T, Deinococcus saxicola sp. nov., (DSM 15974T) came from antarctic sandstone, and Deinococcus marmoris sp. nov. (isolate AA-63T [DSM 12784T]) as well as AA-69 (DSM 15951) were isolated from antarctic marble.

  12. Expression of PprI from Deinococcus radiodurans Improves Lactic Acid Production and Stress Tolerance in Lactococcus lactis.

    Directory of Open Access Journals (Sweden)

    Xiangrong Dong

    Full Text Available PprI is a general switch protein that regulates the expression of certain proteins involved in pathways of cellular resistance in the extremophilic bacterium Deinococcus radiodurans. In this study, we transformed pprI into Lactococcus lactis strain MG1363 using the lactococcal shuttle vector pMG36e and investigated its effects on the tolerance and lactic acid production of L. lactis while under stress. PprI was stably expressed in L. lactis as confirmed by western blot assays. L. lactis expressing PprI exhibited significantly improved resistance to oxidative stress and high osmotic pressure. This enhanced cellular tolerance to stressors might be due to the regulation of resistance-related genes (e.g., recA, recO, sodA, and nah by pprI. Moreover, transformed L. lactis demonstrated increased lactic acid production, attributed to enhanced lactate dehydrogenase activity. These results suggest that pprI can improve the tolerance of L. lactis to environmental stresses, and this transformed bacterial strain is a promising candidate for industrial applications of lactic acid production.

  13. Expression of PprI from Deinococcus radiodurans Improves Lactic Acid Production and Stress Tolerance in Lactococcus lactis.

    Science.gov (United States)

    Dong, Xiangrong; Tian, Bing; Dai, Shang; Li, Tao; Guo, Linna; Tan, Zhongfang; Jiao, Zhen; Jin, Qingsheng; Wang, Yanping; Hua, Yuejin

    2015-01-01

    PprI is a general switch protein that regulates the expression of certain proteins involved in pathways of cellular resistance in the extremophilic bacterium Deinococcus radiodurans. In this study, we transformed pprI into Lactococcus lactis strain MG1363 using the lactococcal shuttle vector pMG36e and investigated its effects on the tolerance and lactic acid production of L. lactis while under stress. PprI was stably expressed in L. lactis as confirmed by western blot assays. L. lactis expressing PprI exhibited significantly improved resistance to oxidative stress and high osmotic pressure. This enhanced cellular tolerance to stressors might be due to the regulation of resistance-related genes (e.g., recA, recO, sodA, and nah) by pprI. Moreover, transformed L. lactis demonstrated increased lactic acid production, attributed to enhanced lactate dehydrogenase activity. These results suggest that pprI can improve the tolerance of L. lactis to environmental stresses, and this transformed bacterial strain is a promising candidate for industrial applications of lactic acid production.

  14. Understanding the role of RecN in DSB repair pathway in Deinococcus radiodurans

    International Nuclear Information System (INIS)

    Pellegrino, S.

    2012-01-01

    Deinococcus radiodurans is a Gram-positive bacterium known for its extreme resistance to a broad variety of DNA damaging agents. Among these, Ionizing Radiations and desiccation are the most harmful for the cell, since they introduce breaks in the genome. Double Strand Breaks (DSB) are particularly hazardous for the cell and they need to be repaired very efficiently, in order to avoid mutations leading to altered, if not lethal, phenotypes. Homologous Recombination (HR) is the most efficient mechanism by which DSBs are repaired. D. radiodurans is able to completely restore its genome in only 3 hours, and it accomplishes the entire process through the RecFOR pathway. In order to be repaired, DSBs first need to be recognized. The protein believed to be responsible for this important step that takes place soon after the damage occurs in the cell, is RecN. RecN is recruited at the early stages of DNA repair and in vivo studies have demonstrated its propensity to localize to discrete foci. In vitro studies also suggest that RecN possesses a DNA end-joining activity previously observed for SMC proteins (such as cohesin), which are structurally related to RecN. Several structural studies have been carried out on the SMC-like protein, Rad50, but so far no structural information is available for RecN. The work presented here focused on the structural characterization of RecN and its constitutive domains. We obtained crystal structures of three partially overlapping constructs of RecN and Small Angle X-ray Scattering was performed on the individual domains and the full-length protein. The study of RecN in solution complemented our crystallographic study and enabled us to build a reliable, atomic model of the full-length protein. Mutations were designed and the mutant RecN proteins were produced in order to characterize the ATP hydrolysis activity of RecN, which is a conserved feature of this family of proteins. Extensive biochemical studies were carried out on wild-type and

  15. Investigation of DNA damage and repair mechanism using deinococcus radiodurans

    International Nuclear Information System (INIS)

    Lau How Mooi; Kikuchi, M.; Kobayashi, Y.; Narumi, I.; Watanabe, H.

    1997-01-01

    Deninococcus Radiodurans, formerly known as Micrococcus Radiodurans, is a popular bacterium because of its high resistance to damage by carcinogens such as ionizing radiation (Dean et. al. 1966; Kitayama and Matsuyama 1968) and UV radiation (Gasvon et. al., 1995; Arrange et. al. 1993). In this report, we investigated the high resistance to ionizing radiation by this bacterium. The bacteria had been exposed from I to 5 kGy of gamma radiation and then incubated in TGY medium to study their ability to repair the broken DNA. The repair time was measured by Pulse Field Gel Electrophoresis (PFGE) method. The repair time for each dose was determined. Also in order to ensure that the repair was perfect, the bacterium was subjected to a second exposure of ionizing radiation after it has fully repaired. It was found that the 'second' repair characteristic was similar to the first repair. This confirmed that the repair after the exposure to the ionizing radiation was perfect

  16. Inhibition of peptide bond formation by pleuromutilins: the structure of the 50S ribosomal subunit from Deinococcus radiodurans in complex with tiamulin.

    Science.gov (United States)

    Schlünzen, Frank; Pyetan, Erez; Fucini, Paola; Yonath, Ada; Harms, Jörg M

    2004-12-01

    Tiamulin, a prominent member of the pleuromutilin class of antibiotics, is a potent inhibitor of protein synthesis in bacteria. Up to now the effect of pleuromutilins on the ribosome has not been determined on a molecular level. The 3.5 A structure of the 50S ribosomal subunit from Deinococcus radiodurans in complex with tiamulin provides for the first time a detailed picture of its interactions with the 23S rRNA, thus explaining the molecular mechanism of the antimicrobial activity of the pleuromutilin class of antibiotics. Our results show that tiamulin is located within the peptidyl transferase center (PTC) of the 50S ribosomal subunit with its tricyclic mutilin core positioned in a tight pocket at the A-tRNA binding site. Also, the extension, which protrudes from its mutilin core, partially overlaps with the P-tRNA binding site. Thereby, tiamulin directly inhibits peptide bond formation. Comparison of the tiamulin binding site with other PTC targeting drugs, like chloramphenicol, clindamycin and streptogramins, may facilitate the design of modified or hybridized drugs that extend the applicability of this class of antibiotics.

  17. Identification of uvrA gene mutation sites in two mitomycin-sensitive deinococcus radiodurans strains

    International Nuclear Information System (INIS)

    Du Zeji; Kong Xianrong

    1999-01-01

    Deinococcus radiodurans (Dr) possesses a prominent ability to repair the DNA injury induced by various DNA- damaging agents including mitomycin C(MC), ultraviolet light (UV) and ionizing radiation. DNA damage resistance was restored in MC sensitive (MC s ) mutants 2621 and 3021 by transforming with DNAs of four cosmids clones derived from the gene library of strain KD8301 which showed the property of wild type phenotype to DNA-damaging agents. Gene affected by mutation (mtcA or mtcB) in both mutants was cloned and its nucleotide sequence was determined. The deduced amino acid (aa) sequence of Dr uvrA gene product consists of 1016 aa and shares homology with many bacterial UvrA proteins. The mutation sites in both mutants were identified by analyzing the polymerase chain reaction (PCR) fragments derived from the genomic DNA of the mutants. A 144-base pairs (bp) deletion including the start codon for the uvr A gene was observed in DNA of the mutant 3021, causing a defect in the gene. On the other hand, an insertion sequence (IS) element intervened in the uvrA gene of the mutant 2621, suggesting the insertional inactivation of the gene. The IS element comprise 1322-bp long, flanked by 19-bp inverted terminal repeats (ITR), and generated a 6-bp target duplication (TD). Two open reading frames (ORF) were found in the IS element. The deduced aa sequences of large and small ORF show homology to a putative transposes found in IS4 of Escherichia coli (E. coli) and to a resolvent found in IS Xc5 of Xanthomonas campestris (Xc), respectively. This is the first discovery of IS element in deino-bacteria, and the IS element was designated IS2621

  18. Molecular cloning and analysis of DNA repair gene from the radioresistant bacterium deinococcus radiodurans

    International Nuclear Information System (INIS)

    Du Zeji; Wang Mingsuo

    1998-12-01

    Deinococcus radiodurans (Dr) possesses a prominent ability to repair DNA injury induced by various DNA-damaging agents including mitomycin C (MC), ultraviolet light (UV) and ionizing radiation. A DNA repair mutant Dr KH3111 is a streptomycin resistant (Sm R ) derivative of KH311 which is generated by treatment with nitrosoguanidine and is sensitive to MC, 8-trimethyl-psoralen, UV and γ-ray irradiation. Gene affected by a mutation in the mutant is identified and its nucleotide sequence is determined. A complete open reading frame (ORF) which encompassed the KH3111 mutation region is found and tentatively designated as orf144b. The deduced amino acid (aa) sequence of orf144b consists of 284 aa and has no significant homology to other known proteins. The exact KH3111 mutation site is one nucleotide altered (G to A) in the sequence of orf144b in the mutant. The KH3111 mutation causes the substitution of Gly for Glu at aa position 149 of Orf144b. Survival measurements of a revertant KH3112 which was produced by transforming with DNA containing a part of the orf144b gene of KD8301 showed that the resistances to MC, UV and γ-ray in the revertant were fully restored at a level equal to the wild type. Thus, the orf144b gene required for the multiple-DNA-damaging agent resistance of Dr was designated with the name of pprA (Pleiotropic gene promoting DNA repair). This new gene can express in E. coli at very high level, and make the host E. coli resistant to MC, UV and γ-ray. The pprA gene does not express in normal Dr, but it can be induced to express by treatment with MC, UV and γ-ray. It was thought that the PprA polypeptide is a cytoplasmic protein because of the absence of characteristics found in the aa sequence of membrane proteins

  19. Proteomics of post-irradiation recovery in D. radiodurans

    International Nuclear Information System (INIS)

    Basu, Bhakti; Apte, Shree Kumar

    2012-01-01

    An extremophile Deinococcus radiodurans is bestowed with an extraordinary DNA repair ability that renders it virtually resistant to all known forms of DNA damage caused by ionizing radiations (10 kGy of gamma rays), UV (1 kJ/m 2 ) or weeks of desiccation etc. The genome of D. radiodurans encodes a unique combination of DNA repair pathways such as prokaryotic type RecFOR mediated homologous recombination (HR) and nucleotide/base excision repair along with eukaryotic type strand annealing (SA) and non-homologous end joining (NHEJ), but is devoid of universal prokaryotic DNA repair pathways such as RecBCD mediated HR, photo-reactivation and SOS response. Collective evidence obtained so far from multiple approaches, have indicated (i) that all genes essential for DNA repair are not necessarily induced following radiation stress (ii) early RecA independent DNA assembly occurs, and (iii) absolute necessity of RecA dependent HR for final genome restitution. The 6 kGy gamma irradiation inducible proteome dynamics were mapped during the post-irradiation growth arrest phase by 2D protein electrophoresis coupled with mass spectrometry. Radiation inducible expression of at least 33 proteins was evident in the first 1h of post irradiation recovery

  20. Structure determination of uracil-DNA N-glycosylase from Deinococcus radiodurans in complex with DNA.

    Science.gov (United States)

    Pedersen, Hege Lynum; Johnson, Kenneth A; McVey, Colin E; Leiros, Ingar; Moe, Elin

    2015-10-01

    Uracil-DNA N-glycosylase (UNG) is a DNA-repair enzyme in the base-excision repair (BER) pathway which removes uracil from DNA. Here, the crystal structure of UNG from the extremophilic bacterium Deinococcus radiodurans (DrUNG) in complex with DNA is reported at a resolution of 1.35 Å. Prior to the crystallization experiments, the affinity between DrUNG and different DNA oligonucleotides was tested by electrophoretic mobility shift assays (EMSAs). As a result of this analysis, two 16 nt double-stranded DNAs were chosen for the co-crystallization experiments, one of which (16 nt AU) resulted in well diffracting crystals. The DNA in the co-crystal structure contained an abasic site (substrate product) flipped into the active site of the enzyme, with no uracil in the active-site pocket. Despite the high resolution, it was not possible to fit all of the terminal nucleotides of the DNA complex into electron density owing to disorder caused by a lack of stabilizing interactions. However, the DNA which was in contact with the enzyme, close to the active site, was well ordered and allowed detailed analysis of the enzyme-DNA interaction. The complex revealed that the interaction between DrUNG and DNA is similar to that in the previously determined crystal structure of human UNG (hUNG) in complex with DNA [Slupphaug et al. (1996). Nature (London), 384, 87-92]. Substitutions in a (here defined) variable part of the leucine loop result in a shorter loop (eight residues instead of nine) in DrUNG compared with hUNG; regardless of this, it seems to fulfil its role and generate a stabilizing force with the minor groove upon flipping out of the damaged base into the active site. The structure also provides a rationale for the previously observed high catalytic efficiency of DrUNG caused by high substrate affinity by demonstrating an increased number of long-range electrostatic interactions between the enzyme and the DNA. Interestingly, specific interactions between residues

  1. Isolation and properties of strains of Micrococcus (Deinococcus) radiodurans unable to excise ultraviolet light-induced pyrimidine dimers from DNA: evidence for two excision pathways

    International Nuclear Information System (INIS)

    Moseley, B.E.B.; Evans, D.M.

    1983-01-01

    A mutant of Deinococcus (formerly Micrococcus) radiodurans sensitive to both the lethal effect of mitomycin C and the mutagenic effect of simple alkylating agents, but having wild-type resistance to UV light, was treated with the mutagen N-methyl-N'-nitro-N-nitrosoguanidine. Three strains were isolated that were UV-sensitive, but had wild-type resistance to the lethal effect of methyl methanesulphonate and all were shown to be unable to excise pyrimidine dimers. The three strains UVS9, UVS25 and UVS78 had, in addition to the mutation in mtcA, mutations in loci designated uvsC, uvsD and uvsE, respectively. When the mutant mtcA gene was replaced by its wild-type allele in all three strains they became UV- and mitomycin C-resistant. On incubating the double mutants UVS9, UVS25 and UVS78 with wild-type DNA about 50% of the transformants selected for UV resistance were mitomycin C-sensitive and about 50% resistant depending on whether the mutant mtcA or the uvsC, D or E genes had been replaced by their wild-type alleles. Although strains mutant singly in uvsC, D or E were UV-resistant the rates of excision of pyrimidine dimers differed between them and was slower in all of them than in the wild-type and strain 302. (author)

  2. Characterizing the Catalytic Potential of Deinococcus, Arthrobacter and other Robust Bacteria in Contaminated Subsurface Environments of the Hanford Site

    International Nuclear Information System (INIS)

    Daly, Michael J.

    2006-01-01

    Ionizing Radiation (IR) Resistance in Bacteria. Until recently, there have been no clear physiologic predictors of a cell's ability to recover from ionizing radiation (IR) and other DOE-relevant oxidative stress conditions. In general, the most resistant bacteria have been Gram-positive (e.g., Deinococcus, Arthrobacter, Lactobacillus and Enterococcus spp.) and the most sensitive have been Gram-negative (e.g., Pseudomonas, Shewanella and Neisseria spp.). However, there are several reported exceptions to this paradigm, the Gram-negative cyanobacterium Chroococcidiopsis is extremely resistant to IR, whereas the Gram-positive Micrococcus luteus is sensitive. We have identified biomolecular signatures for radiation sensitivity and resistance which are independent of phylogeny, where very high and very low intracellular Mn/Fe concentration ratios correlated with very high and very low resistances, respectively; and restricting Mn(II) in the famously resistant Deinococcus radiodurans sensitized this eubacterium to IR

  3. Characterizing the Catalytic Potential of Deinococcus, Arthrobacter and other Robust Bacteria in Contaminated Subsurface Environments of the Hanford Site

    Energy Technology Data Exchange (ETDEWEB)

    Daly, Michael J.

    2006-05-01

    Ionizing Radiation (IR) Resistance in Bacteria. Until recently, there have been no clear physiologic predictors of a cell's ability to recover from ionizing radiation (IR) and other DOE-relevant oxidative stress conditions. In general, the most resistant bacteria have been Gram-positive (e.g., Deinococcus, Arthrobacter, Lactobacillus & Enterococcus spp.) and the most sensitive have been Gram-negative (e.g., Pseudomonas, Shewanella & Neisseria spp.). However, there are several reported exceptions to this paradigm, the Gram-negative cyanobacterium Chroococcidiopsis is extremely resistant to IR, whereas the Gram-positive Micrococcus luteus is sensitive. We have identified biomolecular signatures for radiation sensitivity and resistance which are independent of phylogeny, where very high and very low intracellular Mn/Fe concentration ratios correlated with very high and very low resistances, respectively; and restricting Mn(II) in the famously resistant Deinococcus radiodurans sensitized this eubacterium to IR.

  4. RNA-Seq analysis of D. radiodurans find non coding RNAs expressed in response to radiation stress

    International Nuclear Information System (INIS)

    Gadewal, Nikhil; Mukhopadhyaya, Rita

    2015-01-01

    In bacteria discovery of functional RNA molecules that are not translated into protein, noncoding RNAs, became possible with advent of Next Generation Sequencing technology. Bacterial non coding RNAs are typically 50-300 nucleotides long and work as internal signals controlling various levels of gene expression. Deep sequencing of total cellular RNA captures all coding and noncoding transcripts with their differential levels of expression in the transcriptome. It provides a powerful approach to study bacterial gene expression and mechanisms of gene regulation. We subjected the 3 h transcriptome of Deinococcus radiodurans R1 cells post exposure to 6 KGy gamma radiation to 100 x 2 cycles of deep sequencing on the Illumina HiSeq 2000 to look for ncRNA transcripts. Bioinformatics pipeline for analysis and interpretation of RNA Seq data was done in house using Softwares available in public domains. Our sequence data aligned with 21 putative ncRNAs expressed in the intergenic regions of annotated genome of D radiodurans. Verification of 2 ncRNA candidates and 3 transcription factor genes by Real Time PCR confirmed presence of these transcripts in the 3 h transcriptome sequenced by us. Any relationship between ncRNAs and control of radiation induced gene expression in D radiodurans can be proved only after specific gene knock outs in future. (author)

  5. Repair of gamma radiation damage in wild type and a radiation sensitive mutant of Deinococcus radiodurans

    International Nuclear Information System (INIS)

    Mizuma, Nagayo

    1989-01-01

    In an effort to examine production and repair of radiation-induced single and double strand breaks in the DNA, a repair-deficient wild type and a repair-deficient mutant, UV17, of Deinococcus radiodurans were subjected to Co-60 gamma irradiation at a dose rate of 6.3 kGy/hr for wild type and 3.9 kGy/hr for UV17 mutant. The shoulder of the curve of UV17 mutant was narrow but existed with the intercept of 0.7 kGy and the corresponding value of the wild type was 4.2 kGy. Mutant cells exhibited about 6 fold increases in sensitivity for the shoulder relative to the wild type. The D 37 doses in the wild type and the mutant were 0.57 kGy and 0.25 kGy, respectively. From the survival curves, difference in the sensitivity between two strains was mainly due to difference of repair capacity than the number of radiation sensitive target. Sedimentation rate of the main component in the irradiated cells of UV17 mutant increased almost to the level of unirradiated control by the postincubation at 30deg C for 3 hrs. The results indicated that this sensitive mutant also exhibited an ability to restore single strand breaks after exposure to a sublethal dose of 0.6 kGy. When restitution of double strand breaks was analyzed by sedimentation in a neutral sucrose gradient, the wild type showed restitution to DNA-membrane complex from large part of the breaks. For UV17 mutant, the apparent increase in DNA-membrane complex formation was seen after 3 hours incubation. Large part of the decrease in the activities of peak 2 was recovered in the peak 1 for the wild type. For the mutant, there was little restitution to peak 1. Almost free DNA component in UV17 mutant, therefore, was merely degraded into shorter pieces. Restoration of DNA-membrane complex from free DNA derived from gamma-ray induced double strand scission involved closely in the repair of gamma-induced damage and survival. (N.K.)

  6. Characterizing the Catalytic Potential of Deinococcus, Arthrobacter and other Robust Bacteria in Contaminated Subsurface Environments of the Hanford Site

    International Nuclear Information System (INIS)

    Fredrickson, Jim K.; Daly, Michael J.

    2006-01-01

    Until recently, there have been no clear physiologic predictors of a cell's ability to recover from ionizing radiation (IR), desiccation, and other DOE-relevant oxidative stress conditions. In general, the most resistant bacteria have been Gram-positive (e.g., Deinococcus, Arthrobacter, Lactobacillus and Enterococcus spp.) and the most sensitive have been Gram-negative (e.g., Pseudomonas, Shewanella and Neisseria spp.). However, there are several reported exceptions to this paradigm, the Gram-negative cyanobacterium Chroococcidiopsis is extremely resistant to IR, whereas the Gram-positive Micrococcus luteus is sensitive. We have identified biomolecular signatures for radiation sensitivity and resistance which are independent of phylogeny, where very high and very low intracellular Mn/Fe concentration ratios correlated with very high and very low resistances, respectively; and restricting Mn(II) in the famously resistant Deinococcus radiodurans sensitized this eubacterium to IR (http://cfyn.ifas.ufl.edu/radiation.pdf)

  7. Characterizing the Catalytic Potential of Deinococcus, Arthrobacter and other Robust Bacteria in Contaminated Subsurface Environments of the Hanford Site

    Energy Technology Data Exchange (ETDEWEB)

    Fredrickson, Jim K.; Daly, Michael J.

    2006-06-01

    Until recently, there have been no clear physiologic predictors of a cell's ability to recover from ionizing radiation (IR), desiccation, and other DOE-relevant oxidative stress conditions. In general, the most resistant bacteria have been Gram-positive (e.g., Deinococcus, Arthrobacter, Lactobacillus & Enterococcus spp.) and the most sensitive have been Gram-negative (e.g., Pseudomonas, Shewanella & Neisseria spp.). However, there are several reported exceptions to this paradigm, the Gram-negative cyanobacterium Chroococcidiopsis is extremely resistant to IR, whereas the Gram-positive Micrococcus luteus is sensitive. We have identified biomolecular signatures for radiation sensitivity and resistance which are independent of phylogeny, where very high and very low intracellular Mn/Fe concentration ratios correlated with very high and very low resistances, respectively; and restricting Mn(II) in the famously resistant Deinococcus radiodurans sensitized this eubacterium to IR (http://cfyn.ifas.ufl.edu/radiation.pdf).

  8. ORF Alignment: NC_001263 [GENIUS II[Archive

    Lifescience Database Archive (English)

    Full Text Available NC_001263 gi|15805432 >1bplA 2 169 309 525 3e-10 ... gb|AAF09983.1| alpha-dextran end...o-1,6-alpha-glucosidase [Deinococcus radiodurans] ... pir||D75524 alpha-dextran endo-1,6-alpha-glucos...idase - ... Deinococcus radiodurans (strain R1) ref|NP_294128.1| ... alpha-dextran endo-1,6-al

  9. Study of resistance of D. radiodurans to the combined action of ionizing radiation with an electric or magnetic fields exogenous

    International Nuclear Information System (INIS)

    Prado, Georgia Reis

    2011-01-01

    The key goal in radiotherapy is to maximize damages in a tumor while minimizing them in nearby health tissues. Several strategies have been worked out toward the enhancement of cellular radiosensitivity, as the use of exogenous fields. It is studied in this work the resistance of Deinococcus radiodurans to the combined action of conventional and non conventional radiations, with external agents (electric and magnetic fields). D. radiodurans is a bacterium having an extraordinary ability to cope with lethal and mutagenic agents harmful to the DNA, particularly ionizing radiations as gammas and UV. Given its high radioresistance and fast growing, D. radiodurans has been used as solid tumors simulators. Peculiarities associated with radioresistance at the exponential and stationary phases were delineated from growing curves. By measuring survival curves information on radiosensitivity was obtained. In gamma irradiation D. radiodurans exhibited repairing shoulders of 2 and 8 kGy at the exponential and stationary phases, respectively. When gamma irradiations were combined with expositions to the electric field the repairing shoulders were reduced to 1 and 4 kGy at the exponential and stationary phases, respectively. Radioresistance was similar in both growing phases when the number of cells were approximately equalized in these two processes. On the other hand, when gamma irradiations were combined with expositions to the magnetic field the repairing shoulders were reduced to 4 and 6 kGy at the exponential and stationary phases, respectively. In irradiations with electron beams the repairing shoulder at the exponential phase was totally depleted, while at the stationary phase it was only 1 kGy. The findings of this work revealed new and important information on the radioresistance of D. radiodurans, while providing hints to the improvement of radiotherapy protocols in association with exogenous physical agents. (author)

  10. Comparison of radiation-induced proteins in two revertants with those in a radiation sensitive mutant of Deinococcus radiodurans

    International Nuclear Information System (INIS)

    Hu Qian; Tanaka, Atsushi; Kobayashi, Yasuhiko; Nozawa, Ranko; Watanabe, Hiroshi.

    1992-01-01

    In order to search proteins responsible for DNA repair, the intracellular proteins in gamma-irradiated cells of D.radiodurans R1 and its three mutants were analyzed by means of two-dimensional gel electrophoresis. Two new proteins, P35 (M.W. 35 kDa) and P92 (M.W. 92 kDa), were found in the cells of the radioresistant revertant (KH8401-1-5) and D.radiodurans R1. However, only P92 was detected in the moderately radioresistant revertant (KH8401-10-7). Both proteins were not detected in the cells of the radiosensitive mutant (KH8401). On the other hand, one protein, P25 (M.W. 25 kDa), which was detected either before or after gamma-irradiation, was only found in KH8401-10-7. These results suggest that these special induced proteins, P35 and P92, might be directly responsible for radiation resistance. The analyses of similar proteins in the cells of E.coli B/r and Deinobactor grandis KS0460 were also carried out. (author)

  11. Genetic engineering of a radiation-resistant bacterium for biodegradation of mixed wastes. 1998 annual progress report

    International Nuclear Information System (INIS)

    Lidstrom, M.E.

    1998-01-01

    'Because of their tolerance to very high levels of ionizing radiation, members of the genus Deinococcus have received considerable attention over the past years. The type species of the genus, Deinococcus radiodurans, has been studied extensively in several labs. Although researchers are only beginning to understand the mechanisms by which this Gram-positive bacterium is able to repair massive DNA damage after radiation dosages as high as 5 Mrad, it has become evident that its recombination machinery has several unique characteristics (1--4). The aim of the present studies is to engineer D. radiodurans into a detoxifier for bioremediation of complex waste mixtures, containing heavy metals, halo-organics and radionuclides, making use of its ability to be biologically active in environments where they will be exposed to high levels of radiation. For that purpose, the authors aim to clone and express several broad spectrum oxygenases and heavy metal resistance determinants, and test survival and activities of these strains in artificial mixtures of contaminants, designed to simulate DOE mixed waste streams. This report summarizes work after 0.5 year of a 3-year project. The initial studies have focused on the development of an insertional expression system for D. radiodurans R1. This effort has involved two parts, namely: (1) promoter analysis, and (2) development of insertion systems. Several studies have shown that the expression signals used by D. radiodurans differ considerably from those found in other bacteria. Although D. radiodurans contains a typical eubacterial RNA polymerase core enzyme (based on TBLASTN searches on the genome sequence), Escherichia coli promoters are not recognized in D. radiodurans and vice versa (5). To expand the basic understanding of the requirements for transcription, and to optimize expression of (heterologous) genes, they will follow two strategies. First, a promoter-probe vector is being developed for the selection of promoter

  12. Single Strand Annealing Plays a Major Role in RecA-Independent Recombination between Repeated Sequences in the Radioresistant Deinococcus radiodurans Bacterium.

    Directory of Open Access Journals (Sweden)

    Solenne Ithurbide

    2015-10-01

    Full Text Available The bacterium Deinococcus radiodurans is one of the most radioresistant organisms known. It is able to reconstruct a functional genome from hundreds of radiation-induced chromosomal fragments. Our work aims to highlight the genes involved in recombination between 438 bp direct repeats separated by intervening sequences of various lengths ranging from 1,479 bp to 10,500 bp to restore a functional tetA gene in the presence or absence of radiation-induced DNA double strand breaks. The frequency of spontaneous deletion events between the chromosomal direct repeats were the same in recA+ and in ΔrecA, ΔrecF, and ΔrecO bacteria, whereas recombination between chromosomal and plasmid DNA was shown to be strictly dependent on the RecA and RecF proteins. The presence of mutations in one of the repeated sequence reduced, in a MutS-dependent manner, the frequency of the deletion events. The distance between the repeats did not influence the frequencies of deletion events in recA+ as well in ΔrecA bacteria. The absence of the UvrD protein stimulated the recombination between the direct repeats whereas the absence of the DdrB protein, previously shown to be involved in DNA double strand break repair through a single strand annealing (SSA pathway, strongly reduces the frequency of RecA- (and RecO- independent deletions events. The absence of the DdrB protein also increased the lethal sectoring of cells devoid of RecA or RecO protein. γ-irradiation of recA+ cells increased about 10-fold the frequencies of the deletion events, but at a lesser extend in cells devoid of the DdrB protein. Altogether, our results suggest a major role of single strand annealing in DNA repeat deletion events in bacteria devoid of the RecA protein, and also in recA+ bacteria exposed to ionizing radiation.

  13. Radiation and desiccation response motif mediates radiation induced gene expression in D. radiodurans

    International Nuclear Information System (INIS)

    Anaganti, Narasimha; Basu, Bhakti; Apte, Shree Kumar

    2015-01-01

    Deinococcus radiodurans is an extremophile that withstands lethal doses of several DNA damaging agents such as gamma irradiation, UV rays, desiccation and chemical mutagens. The organism responds to DNA damage by inducing expression of several DNA repair genes. At least 25 radiation inducible gene promoters harbour a 17 bp palindromic sequence known as radiation and desiccation response motif (RDRM) implicated in gamma radiation inducible gene expression. However, mechanistic details of gamma radiation-responsive up-regulation in gene expression remain enigmatic. The promoters of highly radiation induced genes ddrB (DR0070), gyrB (DR0906), gyrA (DR1913), a hypothetical gene (DR1143) and recA (DR2338) from D. radiodurans were cloned in a green fluorescence protein (GFP)-based promoter probe shuttle vector pKG and their promoter activity was assessed in both E. coli as well as in D. radiodurans. The gyrA, gyrB and DR1143 gene promoters were active in E. coli although ddrB and recA promoters showed very weak activity. In D. radiodurans, all the five promoters were induced several fold following 6 kGy gamma irradiation. Highest induction was observed for ddrB promoter (25 fold), followed by DR1143 promoter (15 fold). The induction in the activity of gyrB, gyrA and recA promoters was 5, 3 and 2 fold, respectively. To assess the role of RDRM, the 17 bp palindromic sequence was deleted from these promoters. The promoters devoid of RDRM sequence displayed increase in the basal expression activity, but the radiation-responsive induction in promoter activity was completely lost. The substitution of two conserved bases of RDRM sequence yielded decreased radiation induction of PDR0070 promoter. Deletion of 5 bases from 5'-end of PDR0070 RDRM increased basal promoter activity, but radiation induction was completely abolished. Replacement of RDRM with non specific sequence of PDR0070 resulted in loss of basal expression and radiation induction. The results demonstrate that

  14. Intrinsically disordered regions may lower the hydration free energy in proteins: a case study of nudix hydrolase in the bacterium Deinococcus radiodurans.

    Directory of Open Access Journals (Sweden)

    Omar Awile

    Full Text Available The proteome of the radiation- and desiccation-resistant bacterium D. radiodurans features a group of proteins that contain significant intrinsically disordered regions that are not present in non-extremophile homologues. Interestingly, this group includes a number of housekeeping and repair proteins such as DNA polymerase III, nudix hydrolase and rotamase. Here, we focus on a member of the nudix hydrolase family from D. radiodurans possessing low-complexity N- and C-terminal tails, which exhibit sequence signatures of intrinsic disorder and have unknown function. The enzyme catalyzes the hydrolysis of oxidatively damaged and mutagenic nucleotides, and it is thought to play an important role in D. radiodurans during the recovery phase after exposure to ionizing radiation or desiccation. We use molecular dynamics simulations to study the dynamics of the protein, and study its hydration free energy using the GB/SA formalism. We show that the presence of disordered tails significantly decreases the hydration free energy of the whole protein. We hypothesize that the tails increase the chances of the protein to be located in the remaining water patches in the desiccated cell, where it is protected from the desiccation effects and can function normally. We extrapolate this to other intrinsically disordered regions in proteins, and propose a novel function for them: intrinsically disordered regions increase the "surface-properties" of the folded domains they are attached to, making them on the whole more hydrophilic and potentially influencing, in this way, their localization and cellular activity.

  15. Comparative analyses reveal different consequences of two oxidative stress inducers, gamma irradiation and potassium tellurite, in the extremophile Deinococcus radiodurans

    International Nuclear Information System (INIS)

    Narasimha, Anaganti; Basu, Bhakti; Apte, Shree Kumar

    2014-01-01

    Proteomic and mass spectrometric analyses revealed differential responses of D. radiodurans to two oxidative stressors. While both elicited oxidative stress alleviation response, major divergence was observed at the level of DNA repair, metabolic pathways and protein homeostasis. Response to gamma irradiation was focused on DNA repair and ROS scavenging but supported metabolism as well as protein homeostasis. Tellurite, induced oxidative stress alleviation but decreased reducing affected and adversely affected metabolism and protein homeostasis

  16. The study of the extreme radiation tolerance mechanisms of the bacterium Deinococcus deserti by a functional genomics approach

    International Nuclear Information System (INIS)

    Dulermo, R.

    2009-12-01

    The genome of Deinococcus deserti, a highly radiation-tolerant bacterium, was analyzed and compared to those of D. radiodurans and D. geothermalis. About 230 proteins are specifically conserved in these 3 species, including IrrE, a regulator protein essential for radio tolerance. D.deserti has several supplementary DNA repair genes, like imuY and dnaE2 (trans-lesion DNA polymerases). Moreover, D. deserti has 3 recA that code for 2 different RecA proteins (RecAC et RecAP). To study these genes, genetic tools were developed for D. deserti. Different results suggest that IrrE, required for the induction of several genes after irradiation, has peptidase activity. The 2 RecA proteins are functional for DNA repair. D. deserti is mutable by UV, which requires ImuY, DnaE2 and RecAC, but not RecAP. (author)

  17. ORF Alignment: NC_001263 [GENIUS II[Archive

    Lifescience Database Archive (English)

    Full Text Available | ... protease I [Deinococcus radiodurans R1] ... Length = 173 ... Query: 10 ... KKIAILAADGVEEIELTSP...RAAIEAAGGTTELISLEPGEIQSMKGDIEPQEKYRVDHVVS 69 ... KKIAILAADGVEEIELTSPRAAIEA...AGGTTELISLEPGEIQSMKGDIEPQEKYRVDHVVS Sbjct: 1 ... KKIAILAADGVEEIELTSPRAAIEAAGGTTELISLEPGEIQSMKGDIEPQEKYRVDHVVS

  18. Effects of Deinococcus spp. supplement on egg quality traits in laying hens.

    Science.gov (United States)

    Li, I-Chen; Wu, Szu-Yin; Liou, Jenn-Fa; Liu, Hsiao-Hui; Chen, Jiau-Hua; Chen, Chin-Chu

    2018-01-01

    To counter the ill effects of synthetic dyes, bacterial pigment production as an alternative is now one of the promising and emerging fields of research. This study was conducted to evaluate the applicability of Deinococcus genus on the egg quality traits in laying hens. In study I, 24 single comb White Leghorn layers were fed with various 1 wt % Deinococcus bacterial strains for 10 d. In study II, 84 brown Hendrix layers were fed with one of 4 diets containing 0, 0.2, 1, or 5 wt % Deinococcus sp. GKB-Aid 1995 powder for 12 wk. In study III, 60 White Leghorn laying hens were fed either with or without 1 wt % Deinococcus sp. GKB-Aid 1995 powder, 1 wt % Deinococcus sp. GKB-Aid 1995 granules, or 1 wt % Deinococcus sp. GKB-Aid 1995 oily granules for 10 successive d. In all of the experiments, feeding Deinococcus powder did not affect egg quality traits except for the yolk color. In particular, supplementation with all Deinococcus powder treatments changed the yolk color (P 1995. Moreover, longer supplementation of Deinococcus sp. GKB-Aid 1995 in study II had a significant effect on feed conversion ratio. With these findings under consideration, the present study suggests that the Deinococcus species, especially Deinococcus sp. GKB-Aid 1995, can be an excellent candidate for improving egg yolk color in laying hens. © 2017 Poultry Science Association Inc.

  19. Design and construction of deinococcus radiodurans for biodegradation of organic toxins at radioactive DOE waste sites. 1998 annual progress report

    International Nuclear Information System (INIS)

    Daly, M.J.; Minton, K.W.; Wackett, L.P.

    1998-01-01

    'A 1992 survey of DOE waste sites indicates that about 32% of soils and 45% of groundwaters at these sites contain radionuclides and metals plus an organic toxin class. The most commonly reported combinations of these hazardous compounds being radionuclides and metals (e.g., U, Pu, Cs, Pb, Cr, As) plus chlorinated hydrocarbons (e.g., trichloroethylene), fuel hydrocarbons (e.g., toluene), or polychlorinated biphenyls (e.g., Arochlor 1248). These wastes are some of the most hazardous pollutants and pose an increasing risk to human health as they leach into the environment. The objective of this research is to develop novel organisms, that are highly resistant to radiation and the toxic effects of metals and radionuclides, for in-situ bioremediation of organic toxins. Few organisms exist that are able to remediate such environmental organic pollutants, and among those that can, the bacteria belonging to the genus Pseudomonas are the most characterized. Unfortunately, these bacteria are very radiation sensitive. For example, Pseudomonas spp. is even more sensitive than Escherichia coli and, thus, is not suitable as a bioremediation host in environments subjected to radiation. By contrast, D. radiodurans, a natural soil bacterium, is the most radiation resistant organism yet discovered; it is several thousand times more resistant to ionizing radiation than Pseudomonas. The sophisticated gene transfer and expression systems the authors have developed for D. radiodurans over the last eight years make this organism an ideal candidate for high-level expression of genes that degrade organic toxins, in radioactive environments. The authors ultimate aim is to develop organisms and approaches that will be useful for remediating the large variety of toxic organic compounds found in DOE waste sites that are too radioactive to support other bioremediation organisms. This report summarizes work after the first 6 months of a 3-year project.'

  20. Deinococcus metallilatus sp. nov. and Deinococcus carri sp. nov., isolated from a car air-conditioning system.

    Science.gov (United States)

    Kim, Dong-Uk; Lee, Hyosun; Lee, Ji-Hyeong; Ahn, Jae-Hyung; Lim, Sangyong; Jeong, Sunwook; Park, So Yoon; Seong, Chi Nam; Ka, Jong-Ok

    2015-09-01

    Two bacterial strains, designated MA1002(T) and MA1003(T), were isolated from the air-conditioning system of a car. Cells of both strains were Gram-reaction-positive, non-motile, non-spore-forming coccoids, catalase- and oxidase-positive and UV-radiation resistant. The major fatty acids of strain MA1002(T) were iso-C17 : 0 and iso-C15 : 0 and those of strain MA1003(T) were iso-C16 : 0 and iso-C16 : 1 H. The polar lipid profile of MA1002(T) contained phosphatidylethanolamine, two unidentified phosphoglycolipids, an unidentified phospholipid, an unidentified aminophospholipid, an unidentified aminolipid and an unidentified lipid. MA1003(T) had three unidentified phosphoglycolipids, six unidentified phospholipids, two unidentified glycolipids and two unidentified polar lipids as the polar lipids. The G+C contents of the genomic DNA of MA1002(T) and MA1003(T) were 70.5 and 76.0 mol%, respectively. MK-8 was the predominant respiratory quinone for both strains. 16S rRNA gene sequence analysis showed that strain MA1002(T) was phylogenetically related to Deinococcus apachensis DSM 19763(T), D. geothermalis DSM 11300(T), D. aerius TR0125(T) and D. aetherius ST0316(T) (92.9, 92.6, 92.0 and 91.9% sequence similarity, respectively), and MA1003(T) showed the highest sequence similarity to Deinococcus hopiensis KR-140(T) (92.9%) and D. xinjiangensis X-82(T) (91.4%). The results of genotypic and phenotypic characterizations showed that both strains could be distinguished from phylogenetically related species, and that the strains represented novel species within the genus Deinococcus, for which we propose the names Deinococcus metallilatus sp. nov. (type strain MA1002(T) = KACC 17964(T) = NBRC 110141(T)) and Deinococcus carri sp. nov. (type strain is MA1003(T) = KACC 17965(T) = NBRC 110142(T)).

  1. Antibiotic Sensitivity of Micrococcus radiodurans

    Science.gov (United States)

    Hawiger, J.; Jeljaszewicz, J.

    1967-01-01

    A wild-type strain of Micrococcus radiodurans and its nonpigmented mutant W1 were tested for sensitivity to 10 antibiotics selected from the standpoint of their mechanism of action. Representatives of groups of antibiotics inhibiting deoxyribonucleic acid (DNA) synthesis, DNA-dependent ribonucleic acid synthesis, protein synthesis, and cell wall synthesis were selected. M. radiodurans and its mutant exhibited full susceptibility to all antibiotics tested (mitomycin C, actinomycin D, chloramphenicol, dihydrostreptomycin, erythromycin, neomycin, kanamycin, benzylpenicillin, bacitracin, and vancomycin), the degree of susceptibility being of the same order as that of a standard strain of Staphylococcus aureus 209 P, with the exception of dihydrostreptomycin. PMID:4166078

  2. Review of anticancer and antioxidant activities of radioresistant ...

    African Journals Online (AJOL)

    Prof. Ogunji

    mechanism underlying the tolerance of these organisms to ionizing radiation. ... radiation dose environment, drastic temperature variations and high salinity ... extremophile like Deinococcus radiodurans for instance, is highly dependent on.

  3. γ-irradiated ribosomes from Micrococcus radiodurans in a cell-free protein synthesizing system

    International Nuclear Information System (INIS)

    Suessmuth, R.; Widmann, A.

    1979-01-01

    γ-irradiation inactivation of isolated ribosomes of Micrococcus radiodurans was studied by examining poly U directed synthesis of polyphenylalanine. Ribosomes of M. radiodurans did not show significant γ-radiation sensitivity up to a dose of approx. 11.6 k Gy. Cells of M. radiodurans take up more magnesium than E. coli cells under the same conditions. The magnesium content of ribosomes of M. radiodurans was 18% higher than that of E.coli ribosomes. A possible relation between Mg 2+ -content and γ-resistance is discussed. (orig.) [de

  4. Gene Expression Analysis of Four Radiation-resistant Bacteria

    OpenAIRE

    Gao, Na; Ma, Bin-Guang; Zhang, Yu-Sheng; Song, Qin; Chen, Ling-Ling; Zhang, Hong-Yu

    2009-01-01

    To investigate the general radiation-resistant mechanisms of bacteria, bioinformatic method was employed to predict highly expressed genes for four radiation-resistant bacteria, i.e. Deinococcus geothermalis (D. geo), Deinococcus radiodurans (D. rad), Kineococcus radiotolerans (K. rad) and Rubrobacter xylanophilus (R. xyl). It is revealed that most of the three reference gene sets, i.e. ribosomal proteins, transcription factors and major chaperones, are generally highly expressed in the four ...

  5. Deinococcus multiflagellatus sp. nov., isolated from a car air-conditioning system.

    Science.gov (United States)

    Kim, Dong-Uk; Lee, Hyosun; Lee, Suyeon; Park, Sooyeon; Yoon, Jung-Hoon; Zhao, Lei; Kim, Min-Kyu; Ahn, Jae-Hyung; Ka, Jong-Ok

    2018-04-01

    A gamma radiation-resistant and pink-to-red pigmented bacterial strain, designated ID1504 T , was isolated from a car air-conditioning system sampled in Korea. The cells were observed to be Gram-stain negative, aerobic, motile with peritrichous flagella and short rod-shaped. Phylogenetically, the strain groups with the members of the genus Deinococcus and exhibits high 16S rRNA gene sequence similarities with Deinococcus arenae SA1 T (94.0%), Deinococcus actinosclerus BM2 T (93.9%) and Deinococcus soli N5 T (93.5%). The predominant fatty acids were identified as C 17:0 , C 16:0 , summed feature 3 (C 16:1 ω7c and/or C 16:1 ω6c) and iso-C 17:0 . The major respiratory quinone was identified as MK-8. The polar lipids were found to be comprised of unidentified phospholipids, unidentified glycolipids, an unidentified aminophospholipid and an unidentified lipid. The DNA G+C content of the strain was determined to be 68.3 mol%. On the basis of the phenotypic, genotypic and chemotaxonomic characteristics, strain ID1504 T should be classified in a novel species in the genus Deinococcus, for which the name Deinococcus multiflagellatus sp. nov. (= KACC 19287 T  = NBRC 112888 T ) is proposed.

  6. Resistance of Micrococcus radiodurans to killing and mutation by agents which damage DNA

    Energy Technology Data Exchange (ETDEWEB)

    Sweet, D M; Moseley, B E.B. [Edinburgh Univ. (UK). School of Agriculture

    1976-02-01

    The resistance of Micrococcus radiodurans to the lethal and mutagenic action of ultraviolet (UV) light, ionising (..gamma..) radiation, mitomycin C (MTC), nitrous acid (NA), hydroxylamine (HA), N-methyl-N'-nitro-N-nitrosoguanidine (NG), ethylmethanesulphonate (EMS) and ..beta..-propiolactone (..beta..PL) has been compared with that of Escherichia coli B/r. M. radiodurans was much more resistant than E. coli B/r to the lethal effects of UV light (by a factor of 33), ..gamma..-radiation (55), NG (15) and NA (62), showed intermediate resistance to MTC (4) and HA (7), but was sensitive to EMS (1) and ..beta..PL (2). M. radiodurans was very resistant to mutagens producing damage which can be repaired by a recombination system, indicating that it possesses an extremely efficient recombination repair mechanism. Both species were equally sensitive to mutation to trimethoprim resistance by NG, but M. radiodurans was more resistant than E. coli B/r to the other mutagens tested, being non-mutable by UV light, ..gamma..-radiation, MTC and HA, and only slightly sensitive to mutation by NA, EMS, and ..beta..PL. The resistance of M. radiodurans to mutation by UV light, ..gamma.. radiation and MTC is consistent with an hypothesis that recombination repair in M. radiodurans is accurate since these mutagens may depend on an 'error-prone' recombination system for their mutagenic effect in E. coli B/r. However, because M. radiodurans is also resistant to mutagens such as HA and EMS, which are mutagenic in E. coli in the absence of an 'error-prone' system, we propose that all the mutagens tested may have a common mode of action in E. coli B/r, but that this mutagenic pathway is missing in M. radiodurans.

  7. Journal of Biosciences | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    Effect of zinc and calcium ions on the rat kidney membrane-bound form of dipeptidyl ... ParA encoded on chromosome II of Deinococcus radiodurans binds to .... Repeated oral administration of capsaicin increases anxiety-like behaviours with ...

  8. Deinococcus daejeonensis sp. nov., isolated from sludge in a sewage disposal plant.

    Science.gov (United States)

    Srinivasan, Sathiyaraj; Kim, Myung Kyum; Lim, Sangyong; Joe, Minho; Lee, Myungjin

    2012-06-01

    A Gram-stain-positive, strictly aerobic, spherical, non-motile red-pigmented bacterial strain, designated MJ27(T), was isolated from a sludge sample of the Daejeon sewage disposal plant in South Korea. A polyphasic approach was used to study the taxonomic position of strain MJ27(T). Strain MJ27(T) shared highest 16S rRNA gene sequence similarity with Deinococcus grandis DSM 3963(T) (98.8 %), Deinococcus caeni Ho-08(T) (97.5 %) and Deinococcus aquaticus PB314(T) (96.6 %.); levels of sequence similarity with the type strains of other Deinococcus species were less than 96.0 %. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain MJ27(T) belonged to the clade formed by members of the genus Deinococcus in the family Deinococcaceae. The G+C content of the genomic DNA of strain MJ27(T) was 67.6 mol%. The chemotaxonomic characteristics of strain MJ27(T) were typical of members of the genus Deinococcus, with MK-8 as the predominant respiratory quinone, C(16:1)ω7c, C(15:1)ω6c, C(16:0) and C(15:0) as major fatty acids (>12 %), ornithine as the diamino acid in the cell-wall peptidoglycan and resistance to gamma radiation [D(10) (dose required to reduce the bacterial population by tenfold) >9 kGy]. The low levels of DNA-DNA relatedness reported here (5.3±1.5-29.2±2.3 %) indicate that strain MJ27(T) represents a species that is separate from its closest relatives in the genus Deinococcus. On the basis of phylogenetic inference, fatty acid profile and other phenotypic properties, strain MJ27(T) is considered to represent a novel species of the genus Deinococcus, for which the name Deinococcus daejeonensis sp. nov. is proposed. The type strain is MJ27(T) ( = KCTC 13751(T) = JCM 16918(T)).

  9. The resistance of Micrococcus radiodurans to killing and mutation by agents which damage DNA

    International Nuclear Information System (INIS)

    Sweet, D.M.; Moseley, B.E.B.

    1976-01-01

    The resistance of Micrococcus radiodurans to the lethal and mutagenic action of ultraviolet (UV) light, ionising (γ) radiation, mitomycin C (MTC), nitrous acid (NA), hydroxylamine (HA), N-methyl-N'-nitro-N-nitrosoguanidine (NG), ethylmethanesulphonate (EMS) and β-propiolactone (βPL) has been compared with that of Escherichia coli B/r. M. radiodurans was much more resistant than E. coli B/r to the lethal effects of UV light (by a factor of 33), γ-radiation (55), NG (15) and NA (62), showed intermediate resistance to MTC (4) and HA (7), but was sensitive to EMS (1) and βPL (2). M. radiodurans was very resistant to mutagens producing damage which can be repaired by a recombination system, indicating that it possesses an extremely efficient recombination repair mechanism. Both species were equally sensitive to mutation to trimethoprim resistance by NG, but M. radiodurans was more resistant than E. coli B/r to the other mutagens tested, being non-mutable by UV light, γ-radiation, MTC and HA, and only slightly sensitive to mutation by NA, EMS, and βPL. The resistance of M. radiodurans to mutation by UV light, γ-radiation and MTC is consistent with an hypothesis that recombination repair in M. radiodurans is accurate since these mutagens may depend on an 'error-prone' recombination system for their mutagenic effect in E. coli B/r. However, because M. radiodurans is also resistant to mutagens such as HA and EMS, which are mutagenic in E. coli in the absence of an 'error-prone' system, we propose that all the mutagens tested may have a common mode of action in E. coli B/r, but that this mutagenic pathway is missing in M. radiodurans

  10. Genetic engineering microbes for bioremediation/ biorecovery of uranium

    International Nuclear Information System (INIS)

    Apte, S.K.; Rao, A.S.; Appukuttan, D.; Nilgiriwala, K.S.; Acharya, C.

    2005-01-01

    Bioremediation (both bioremoval and biorecovery) of metals is considered a feasible, economic and eco-friendly alternative to chemical methods of metal extraction, particularly when the metal concentration is very low. Scanty distribution along with poor ore quality makes biomining of uranium an attractive preposition. Biosorption, bioprecipitation or bioaccumulation of uranium, aided by recombinant DNA technology, offer a promising technology for recovery of uranium from acidic or alkaline nuclear waste, tailings or from sea-water. Genetic engineering of bacteria, with a gene encoding an acid phosphatase, has yielded strains that can bioprecipitate uranium from very low concentrations at acidic-neutral pH, in a relatively short time. Organisms overproducing alkaline phosphatase have been selected for uranium precipitation from alkaline waste. Such abilities have now been transferred to the radioresistant microbe Deinococcus radiodurans to facilitate in situ bioremediation of nuclear waste, with some success. Sulfate-reducing bacteria are being characterized for bioremediation of uranium in tailings with the dual objective of uranium precipitation and reduction of sulfate to sulphide. Certain marine cyanobacteria have shown promise for uranium biosorption to extracellular polysaccharides, and intracellular accumulation involving metal sequestering metallothionin proteins. Future work is aimed at understanding the genetic basis of these abilities and to engineer them into suitable organisms subsequently. As photosynthetic, nitrogen-fixing microbes, which are considerably resistant to ionizing radiations, cyanobacteria hold considerable potential for bioremediation of nuclear waste. (author)

  11. Role of manganese in the resistance of Micrococcus radiodurans to ionizing radiation

    International Nuclear Information System (INIS)

    Wierowski, J.V.

    1980-01-01

    Micrococcus radiodurans possesses a very high level of intracellular manganese compared to other organisms. This manganese content has previously been shown to participate in the exceptional ulraviolet radiation resistance of M. radiodurans. This study was undertaken to determine the role of manganese in the ionizing radiation resistant of M. radiodurans. The results indicate that manganese is essential for DNA degradation to occur during irradiation. Manganese has also proven essential for the second phase of post-irradiation thymine base damage removal. These factors work together to increase the rate of recovery from radiation damage, which is reflected in a larger Dq, D 37 and exponential portion of the survival curve of high Mn-grown cells

  12. Journal of Biosciences | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    In situ real-time evaluation of radiation-responsive promoters in the extremely radioresistant microbe Deinococcus radiodurans · Narasimha Anaganti Bhakti Basu Shree Kumar Apte · More Details Abstract Fulltext PDF. A third generation promoter probe shuttle vector pKG was constructed, using the green fluorescent ...

  13. Journal of Genetics | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    PprA, a pleiotropic protein for radioresistance, works through DNA gyrase and shows cellular dynamics during postirradiation recovery in Deinococcus radiodurans .... Gene interactions and genetics of blast resistance and yield attributes in rice (Oryza ... Molecular mapping of a stripe rust resistance gene in wheat line C51.

  14. Protease activity of PprI facilitates DNA damage response: Mn2+-dependence and substrate sequence-specificity of the proteolytic reaction.

    Directory of Open Access Journals (Sweden)

    Yunguang Wang

    Full Text Available The extremophilic bacterium Deinococcus radiodurans exhibits an extraordinary resistance to ionizing radiation. Previous studies established that a protein named PprI, which exists only in the Deinococcus-Thermus family, acts as a general switch to orchestrate the expression of a number of DNA damage response (DDR proteins involved in cellular radio-resistance. Here we show that the regulatory mechanism of PprI depends on its Mn(2+-dependent protease activity toward DdrO, a transcription factor that suppresses DDR genes' expression. Recognition sequence-specificity around the PprI cleavage site is essential for DNA damage repair in vivo. PprI and DdrO mediate a novel DNA damage response pathway differing from the classic LexA-mediated SOS response system found in radiation-sensitive bacterium Escherichia coli. This PprI-mediated pathway in D. radiodurans is indispensable for its extreme radio-resistance and therefore its elucidation significantly advances our understanding of the DNA damage repair mechanism in this amazing organism.

  15. Extracellular proteolytic activity of Deinococcus geothermalis ...

    African Journals Online (AJOL)

    Nonionic detergents like Triton X-100 and Tween 80 did not affect catalytic properties. It suggested that the enzyme produced by D. geothermalis could be used as a component of detergents. Keywords: Deinococcus geothermalis, alkaline protease, detergents, thermostability. African Journal of Biotechnology Vol. 12(25) ...

  16. Four Proteins Synthesized in Response to Deoxyribonucleic Acid Damage in Micrococcus Radiodurans

    DEFF Research Database (Denmark)

    Hansen, M. T.

    1980-01-01

    Four proteins, alpha beta, gamma, and delta, preferentially synthesized in ultraviolet light-treated cells of Micrococcus radiodurans, were characterized in terms of their molecular weights and isoelectric points. Within the sublethal-dose range, the differential rate of synthesis for these prote......Four proteins, alpha beta, gamma, and delta, preferentially synthesized in ultraviolet light-treated cells of Micrococcus radiodurans, were characterized in terms of their molecular weights and isoelectric points. Within the sublethal-dose range, the differential rate of synthesis...

  17. Separation of DNA-dependent polymerate activities in Micrococcus radiodurans

    International Nuclear Information System (INIS)

    Kitayama, S.; Matsuyama, A.

    1977-01-01

    DNA polymerase activities in Micrococcus radiodurans were separated into two fractions after purification more than 2000 fold. They differ in pH optimum and residual activities in the absence of a full deoxyribonucleoside triphosphates complement. NAD partly inhibited one of the activities. Both activities were eluted as a single peak on gel filtration and sedimented at the same rate on glycerol gradient centrifugation. Molecular weight 140000 was calculated from Stokes radius and sedimentation constant. Deoxyribonuclease activity was detected on one of the polymerase activities which preferentially degraded double-stranded DNA. Priming activity of nicked DNA was reduced by γ-radiation. These results have been related to the possible roles in repair synthesis in vivo or DNA synthesis in permeable cells of M. radiodurans

  18. Separation of DNA-dependent polymerase activities in Micrococcus radiodurans

    Energy Technology Data Exchange (ETDEWEB)

    Kitayama, S; Matsuyama, A [Institute of Physical and Chemical Research, Wako, Saitama (Japan)

    1977-03-02

    DNA polymerase activities in Micrococcus radiodurans were separated into two fractions after purification more than 2000 fold. They differ in pH optimum and residual activities in the absence of a full deoxyribonucleoside triphosphates complement. NAD partly inhibited one of the activities. Both activities were eluted as a single peak on gel filtration and sedimented at the same rate on glycerol gradient centrifugation. Molecular weight 140000 was calculated from Stokes radius and sedimentation constant. Deoxyribonuclease activity was detected on one of the polymerase activities which preferentially degraded double-stranded DNA. Priming activity of nicked DNA was reduced by ..gamma.. radiation. These results have been related to the possible roles in repair synthesis in vivo or DNA synthesis in permeable cells of M. radiodurans.

  19. Clipboard

    Indian Academy of Sciences (India)

    Unknown

    DNA Repair in Deinococcus radiodurans and in Germinating Bacterial Spores; J. Bacteriol. 186 5973–5977. Frenkiel-Krispin D, Levin-Zaidman S, Shimoni E, Wolf S G, Wachtel E J, Arad T, Finkel S E, Kolter R and. Minsky A 2001 Regulated phase transitions of bacterial chromatin: a non-enzymatic pathway for generic DNA.

  20. Quorum sensing circuit and reactive oxygen species resistance in Deinococcus sp.

    Science.gov (United States)

    Fernandez-Bunster, G; Gonzalez, C; Barros, J; Martinez, M

    2012-12-01

    Genus Deinococcus is characterized by an increased resistance toward reactive oxygen species (ROS). The chromosome of five strains belonging to this genus has been sequenced and the presence of a luxS-like gene was deduced from their genome sequences. The aim of this study was to assess if a complete QS circuit is present in Deinococcus sp. and if this QS is associated with ROS. Primers for searching luxS-like gene and the putative receptor gene, namely ai2R, were designed. AI-2 signal production was evaluated by luminescence analysis using Vibrio harveyi BB170 as reporter strain. AI-2 signal was also evaluated by competitive assays using cinnamaldehyde, ascorbic acid, and 3-mercaptopropionic acid as interfering molecules. Potassium tellurite and metronidazole were used as oxidative stressors. A luxS-like gene as well as an ai2R gene was detected in strain UDEC-P1 by PCR. Cell-free supernatant of strain UDEC-P1 culture induced luminescence in V. harveyi BB170, and this property was inhibited with the three interfering molecules. The oxidative stressors metronidazole and potassium tellurite decreased Deinococcus sp. viability, but increased luminescence of the reporter strain. The results demonstrate that both a functional luxS-like gene and a putative receptor for AI-2 signal are present in Deinococcus sp. strain UDEC-P1. This finding also suggests that a complete QS circuit is present in this genus, which could be related to oxidative stress.

  1. Repair of double-strand breaks in Micrococcus radiodurans

    International Nuclear Information System (INIS)

    Burrell, A.D.; Dean, C.J.

    1975-01-01

    Micrococcus radiodurans has been shown to sustain double-strand breaks in its DNA after exposure to x-radiation. Following sublethal doses of x-rays (200 krad in oxygen or less), the cells were able to repair these breaks, and an intermediate fast-sedimenting DNA component seemed to be involved in the repair process

  2. Topoisomerase IB of Deinococcus radiodurans resolves guanine ...

    Indian Academy of Sciences (India)

    2015-11-28

    Nov 28, 2015 ... All the oligonucleotides men- tioned here were ... further reactions with DraTopoIB were carried out at 37°C ... of G4 DNA moves faster than unfolded and intermolecular .... for its action on intramolecular G4 DNA structure was.

  3. The in vivo association of manganese with the chromosome of Micrococcus radiodurans

    International Nuclear Information System (INIS)

    Leibowitz, P.J.; Schwartzberg, L.S.; Bruce, A.K.

    1976-01-01

    Extremely high levels of paramagnetic manganese (Mn 2+ ) which quench phosphorescent reactions have been found to inhibit the formation of thymine-containing dimers in M. radiodurans. Lowering the concentration of Mn 2+ in the culture medium resulted in a lower intracellular concentration of Mn 2+ , an increase in the UV-sensitivity of this bacterium, and a larger photochemical yield of thymine-containing dimers. High levels of paramagnetic Mn 2+ were not found in other test organisms which are more sensitive to UV-irradiation. One interpretation of this data is that in Micrococcus radiodurans Mn2 + + may bind to the chromosome and thereby reduce the photochemical yield of thymine-containing dimers. (author)

  4. Expression of lycopene biosynthesis genes fused in line with Shine-Dalgarno sequences improves the stress-tolerance of Lactococcus lactis.

    Science.gov (United States)

    Dong, Xiangrong; Wang, Yanping; Yang, Fengyuan; Zhao, Shanshan; Tian, Bing; Li, Tao

    2017-01-01

    Lycopene biosynthetic genes from Deinococcus radiodurans were co-expressed in Lactococcus lactis to produce lycopene and improve its tolerance to stress. Lycopene-related genes from D. radiodurans, DR1395 (crtE), DR0862 (crtB), and DR0861 (crtI), were fused in line with S hine-Dalgarno (SD) sequences and co-expressed in L. lactis. The recombinant strain produced 0.36 mg lycopene g -1  dry cell wt after 48 h fermentation. The survival rate to UV irradiation of the recombinant strain was higher than that of the non-transformed strain. The L. lactis with co-expressed genes responsible for lycopene biosynthesis from D. radiodurans produced lycopene and exhibited increased resistance to UV stress, suggesting that the recombinant strain has important application potential in food industry.

  5. Major soluble proteome changes in Deinococcus deserti over the earliest stages following gamma-ray irradiation

    International Nuclear Information System (INIS)

    Dedieu, Alain; Sahinovic, Elodie; Guerin, Philippe; Armengaud, Jean; Blanchard, Laurence; Fochesato, Sylvain; Groot, Arjan de; Meunier, Bruno

    2013-01-01

    Deinococcus deserti VCD115 has been isolated from Sahara surface sand. This radio-tolerant bacterium represents an experimental model of choice to understand adaptation to harsh conditions encountered in hot arid deserts. We analysed the soluble proteome dynamics in this environmentally relevant model after exposure to 3 kGy gamma radiation, a non-lethal dose that generates massive DNA damages. For this, cells were harvested at different time lapses after irradiation and their soluble proteome contents have been analysed by 2-DE and mass spectrometry. In the first stage of the time course we observed accumulation of DNA damage response protein DdrB (that shows the highest fold change ∼11), SSB, and two different RecA proteins (RecAP and RecAC). Induction of DNA repair protein PprA, DNA damage response protein DdrD and the two gyrase subunits (GyrA and GyrB) was also detected. A response regulator of the SarP family, a type II site-specific deoxyribonuclease and a putative N-acetyltransferase are three new proteins found to be induced. In a more delayed stage, we observed accumulation of several proteins related to central metabolism and protein turn-over, as well as helicase UvrD and novel forms of both gyrase subunits differing in terms of isoelectric point and molecular weight. Conclusions: Post-translational modifications of GyrA (N-terminal methionine removal and acetylation) have been evidenced and their significance discussed. We found that the Deide-02842 restriction enzyme, which is specifically found in D. deserti, is a new potential member of the radiation/desiccation response regulon, highlighting the specificities of D. deserti compared to the D. radiodurans model. (authors)

  6. Genetic Engineering of a Radiation-Resistant Bacterium for Biodegradation of Mixed Wastes. Final Report

    International Nuclear Information System (INIS)

    Lidstrom, Mary E.

    2003-01-01

    Aqueous mixed low level wastes (MLLW) containing radionuclides, solvents, and/or heavy metals represent a serious current and future problem for DOE environmental management and cleanup. In order to provide low-cost treatment alternatives under mild conditions for such contained wastes, we have proposed to use the radiation-resistant bacterium, Deinococcus radiodurans. This project has focused on developing D. radiodurans strains for dual purpose processes: cometabolic treatment of haloorganics and other solvents and removal of heavy metals from waste streams in an above-ground reactor system. The characteristics of effective treatment strains that must be attained are: (a) high biodegradative and metal binding activity; (b) stable treatment characteristics in the absence of selection and in the presence of physiological stress; (c) survival and activity under harsh chemical conditions, including radiation. The result of this project has been a suite of strains with high biodegradative capabilities that are candidates for pilot stage treatment systems. In addition, we have determined how to create conditions to precipitate heavy metals on the surface of the bacterium, as the first step towards creating dual-use treatment strains for contained mixed wastes of importance to the DOE. Finally, we have analyzed stress response in this bacterium, to create the foundation for developing treatment processes that maximize degradation while optimizing survival under high stress conditions

  7. The mechanisms of Micrococcus radiodurans radioresistance

    International Nuclear Information System (INIS)

    Samojlenko, I.I.

    1983-01-01

    Modern representations on molecular mechanisms of Micrococcus radiodurans viability under the effect of ionizing radiation have been considered. Factors conditioning a high level of micrococcus cell radiostability have been analyzed: peculiarities of structure of a cell wall, DNA, membranes; excess of genetic information; multiplicity of DNA implantation points to a membrane; high level of antioxidation and antiradical systems. It has been shown that on efficiency of accurate, properly balanced system of DNA repair combined with above Micrococcus radiodurant properties provide a high microorganism radioresistance

  8. The in vivo association of manganese with the chromosome of Micrococcus radiodurans

    Energy Technology Data Exchange (ETDEWEB)

    Leibowitz, P J; Schwartzberg, L S; Bruce, A K [State Univ. of New York, Buffalo (USA). Dept. of Biology

    1976-01-01

    Extremely high levels of paramagnetic manganese (Mn/sup 2 +/) which quench phosphorescent reactions have been found to inhibit the formation of thymine-containing dimers in M. radiodurans. Lowering the concentration of Mn/sup 2 +/ in the culture medium resulted in a lower intracellular concentration of Mn/sup 2 +/, an increase in the uv-sensitivity of this bacterium, and a larger photochemical yield of thymine-containing dimers. High levels of paramagnetic Mn/sup 2 +/ were not found in other test organisms which are more sensitive to uv-irradiation. One interpretation of this data is that in Micrococcus radiodurans Mn2/sup +/+ may bind to the chromosome and thereby reduce the photochemical yield of thymine-containing dimers.

  9. Deinococcus aluminii sp. nov., isolated from an automobile air conditioning system.

    Science.gov (United States)

    Kim, Dong-Uk; Lee, Hyosun; Lee, Suyeon; Park, Sooyeon; Yoon, Jung-Hoon; Zhao, Lei; Kim, Min-Kyu; Ahn, Jae-Hyung; Ka, Jong-Ok

    2018-01-16

    A Gram-stain-positive and pale pink-pigmented bacterial strain, designated ID0501 T , was isolated from an automobile evaporator core collected in the Republic of Korea. The cells were aerobic and coccoidal. The strain grew at 15-40 ˚C (optimum, 37 ˚C), at pH 6.0-7.0 (optimum, pH 6.5), and in the presence of 0-1.5 % (w/v) NaCl. Phylogenetically, the strain was related to members of the genus Deinococcus and showed the highest sequence similarity, of 96.9 %, with Deinococcus metallilatus MA1002 T . The major fatty acids of the strain were iso-C17 : 0, iso-C15 : 0 and iso-C13 : 0. The predominant respiratory quinone was MK-8. The polar lipids profile revealed the presence of phosphatidylethanolamine, phosphatidylglycerol, phosphatidylcholine, diphosphatidylglycerol, unidentified phospholipids, an unidentified aminolipid and unidentified glycolipids. The DNA G+C content of the strain was 68.3 mol%. On the basis of phenotypic, genotypic and chemotaxonomic data, strain ID0501 T represents a novel species of the genus Deinococcus, for which the name Deinococcusaluminii sp. nov. (=KACC 19286 T =NBRC 112889 T ) is proposed.

  10. Genetic control over the processes of postirradiation recovery of a compact chromosome in micrococcus radiodurans

    International Nuclear Information System (INIS)

    Kudryashova, N.Yu.; Groshev, V.V.; Shestakov, S.V.

    1984-01-01

    X-irradiation of Micrococcus radiodurans cells with sublethal doses caused disturbances in the structure of a membrane-bound compact chromosome. Recovery of the compact chromosome occurred during the postirradiation incubation of the wild type cells and cells of the UVS-17 mutant deficient in DNA-polymerase. This process was blocked in cells of rec-30 mutant with the impaired system of genetic recombination: this is indicative of an important role played by rec-30 gene product in the postirradiation recovery of the compact chromosome in M. radiodurans cells

  11. Deinococcus Mn2+-peptide complex: A novel approach to alphavirus vaccine development.

    Science.gov (United States)

    Gayen, Manoshi; Gupta, Paridhi; Morazzani, Elaine M; Gaidamakova, Elena K; Knollmann-Ritschel, Barbara; Daly, Michael J; Glass, Pamela J; Maheshwari, Radha K

    2017-06-22

    Over the last ten years, Chikungunya virus (CHIKV), an Old World alphavirus has caused numerous outbreaks in Asian and European countries and the Americas, making it an emerging pathogen of great global health importance. Venezuelan equine encephalitis virus (VEEV), a New World alphavirus, on the other hand, has been developed as a bioweapon in the past due to its ease of preparation, aerosol dispersion and high lethality in aerosolized form. Currently, there are no FDA approved vaccines against these viruses. In this study, we used a novel approach to develop inactivated vaccines for VEEV and CHIKV by applying gamma-radiation together with a synthetic Mn-decapeptide-phosphate complex (MnDpPi), based on manganous-peptide-orthophosphate antioxidants accumulated in the extremely radiation-resistant bacterium Deinococcus radiodurans. Classical gamma-irradiated vaccine development approaches are limited by immunogenicity-loss due to oxidative damage to the surface proteins at the high doses of radiation required for complete virus-inactivation. However, addition of MnDpPi during irradiation process selectively protects proteins, but not the nucleic acids, from the radiation-induced oxidative damage, as required for safe and efficacious vaccine development. Previously, this approach was used to develop a bacterial vaccine. In the present study, we show that this approach can successfully be applied to protecting mice against viral infections. Irradiation of VEEV and CHIKV in the presence of MnDpPi resulted in substantial epitope preservation even at supra-lethal doses of gamma-rays (50,000Gy). Irradiated viruses were found to be completely inactivated and safe in vivo (neonatal mice). Upon immunization, VEEV inactivated in the presence of MnDpPi resulted in drastically improved protective efficacy. Thus, the MnDpPi-based gamma-inactivation approach described here can readily be applied to developing vaccines against any pathogen of interest in a fast and cost

  12. Multiplicity of genome equivalents in the radiation-resistant bacterium Micrococcus radiodurans.

    Science.gov (United States)

    Hansen, M T

    1978-01-01

    The complexity of the genome of Micrococcus radiodurans was determined to be (2.0 +/- 0.3) X 10(9) daltons by DNA renaturation kinetics. The number of genome equivalents of DNA per cell was calculated from the complexity and the content of DNA. A lower limit of four genome equivalents per cell was approached with decreasing growth rate. Thus, no haploid stage appeared to be realized in this organism. The replication time was estimated from the kinetics and amount of residual DNA synthesis after inhibiting initiation of new rounds of replication. From this, the redundancy of terminal genetic markers was calculated to vary with growth rate from four to approximately eight copies per cell. All genetic material, including the least abundant, is thus multiply represented in each cell. The potential significance of the maintenance in each cell of multiple gene copies is discussed in relation to the extreme radiation resistance of M. radiodurans. PMID:649572

  13. Small-Molecule Antioxidant Proteome-Shields in Deinococcus Radiodurans

    Science.gov (United States)

    2010-09-01

    family of proteases [14] which appear to be activated by irradiation (Figure 4B). At least 10 complete open reading frames with considerable sequence...the experiments: MJD EKG VYM JGK RF DYL NBW GAV BSB RLL. Performed the experiments: MJD EKG VYM JGK RF DYL NBW GAV BSB RLL. Analyzed the data: MJD... EKG VYM JGK RF DYL NBW GAV BSB RLL. Wrote the paper: MJD RLL. References 1. Daly MJ, Gaidamakova EK, Matrosova VY, Vasilenko A, Zhai M, et al. (2007

  14. Research of radiation-resistant microbial organisms

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Dongho; Lim, Sangyong; Joe, Minho; Park, Haejoon; Song, Hyunpa; Im, Seunghun; Kim, Haram; Kim, Whajung; Choi, Jinsu; Park, Jongchun

    2012-01-15

    Many extremophiles including radiation-resistant bacteria Deinococcus radiodurans have special characteristics such as novel enzymes and physiological active substances different from known biological materials and are being in the spotlight of biotechnology science. In this research, basic technologies for the production of new genetic resources and microbial strains by a series of studies in radiation-resistant microbial organisms were investigated and developed. Mechanisms required for radiation-resistant in Deinococcus radiodurans were partly defined by analyzing the function of dinB, pprI, recG, DRA{sub 0}279, pprM, and two-component signal transduction systems. To apply genetic resource and functional materials from Deinococcus species, omics analysis in response to cadmium, construction of macroscopic biosensor, and characterization of carotenoids and chaperon protein were performed. Additionally, potential use of D. geothermalis in monosaccharide production from non-biodegradable plant materials was evaluated. Novel radiation resistant yeasts and bacteria were isolated and identified from environmental samples to obtain microbial and genomic resources. An optimal radiation mutant breeding method was set up for efficient and rapid isolation of target microbial mutants. Furthermore, an efficient ethanol producing mutant strain with high production yield and productivity was constructed using the breeding method in collaboration with Korea Research Institute of Bioscience and Biotechnology. Three Deinococcal bioindicators for radiation dosage confirmation after radiation sterilization process were developed. These results provide a comprehensive information for novel functional genetic elements, enzymes, and physiological active substances production or application. Eventually, industrial microbial cell factories based on radiation resistant microbial genomes can be developed and the technologies can be diffused to bioindustry continuously by this project.

  15. Research of radiation-resistant microbial organisms

    International Nuclear Information System (INIS)

    Kim, Dongho; Lim, Sangyong; Joe, Minho; Park, Haejoon; Song, Hyunpa; Im, Seunghun; Kim, Haram; Kim, Whajung; Choi, Jinsu; Park, Jongchun

    2012-01-01

    Many extremophiles including radiation-resistant bacteria Deinococcus radiodurans have special characteristics such as novel enzymes and physiological active substances different from known biological materials and are being in the spotlight of biotechnology science. In this research, basic technologies for the production of new genetic resources and microbial strains by a series of studies in radiation-resistant microbial organisms were investigated and developed. Mechanisms required for radiation-resistant in Deinococcus radiodurans were partly defined by analyzing the function of dinB, pprI, recG, DRA 0 279, pprM, and two-component signal transduction systems. To apply genetic resource and functional materials from Deinococcus species, omics analysis in response to cadmium, construction of macroscopic biosensor, and characterization of carotenoids and chaperon protein were performed. Additionally, potential use of D. geothermalis in monosaccharide production from non-biodegradable plant materials was evaluated. Novel radiation resistant yeasts and bacteria were isolated and identified from environmental samples to obtain microbial and genomic resources. An optimal radiation mutant breeding method was set up for efficient and rapid isolation of target microbial mutants. Furthermore, an efficient ethanol producing mutant strain with high production yield and productivity was constructed using the breeding method in collaboration with Korea Research Institute of Bioscience and Biotechnology. Three Deinococcal bioindicators for radiation dosage confirmation after radiation sterilization process were developed. These results provide a comprehensive information for novel functional genetic elements, enzymes, and physiological active substances production or application. Eventually, industrial microbial cell factories based on radiation resistant microbial genomes can be developed and the technologies can be diffused to bioindustry continuously by this project

  16. Inactivation of the Radiation-Resistant Spoilage Bacterium Micrococcus radiodurans

    Science.gov (United States)

    Duggan, D. E.; Anderson, A. W.; Elliker, P. R.

    1963-01-01

    A simplified technique permitting the pipetting of raw puréed meats for quantitative bacteriological study is described for use in determining survival of these non-sporing bacteria, which are exceptionally resistant to radiation. Survival curves, using gamma radiation as the sterilizing agent, were determined in raw beef with four strains of Micrococcus radiodurans. Survival curves of the R1 strain in other meat substrates showed that survival was significantly greater in raw beef and raw chicken than in raw fish or in cooked beef. Resistance was lowest in the buffer. Cells grown in broth (an artificial growth medium) and resuspended in beef did not differ in resistance from cells that had been grown and irradiated in beef. Survival rate was statistically independent of the initial cell concentration, even though there appeared to be a correlation between lower death rate and lower initial cell concentrations. The initial viable count of this culture of the domesticated R1 strain in beef was reduced by a factor of about 10-5 by 3.0 megarad, and 4.0 megarad reduced the initial count by a factor of more than 10-9. Data suggest that M. radiodurans R1 is more resistant to radiation than spore-forming spoilage bacteria for which inactivation rates have been published. PMID:14063780

  17. The deoxyribonucleic acid of Micrococcus radiodurans

    Science.gov (United States)

    Schein, Arnold H.

    1966-01-01

    The DNA of Micrococcus radiodurans was prepared by three methods. Although the recovery of DNA varied considerably, the percentage molar base ratios of the DNA from the three preparations were essentially the same: guanine, 33±2; adenine, 18±1; cytosine, 33±2; thymine, 17±1. Base compositions calculated from Tm values and from density in caesium chloride gradients also yielded guanine+cytosine contents of 66 and 68% of total bases respectively. No unusual bases were observed. The S20,w values were characteristic of high-molecular-weight DNA. Electron microscopy showed the purified DNA in long strands; occasionally these were coiled. Images(a)(b)(c)(d)(e)Fig. 1. PMID:16742439

  18. Excision repair of 5,6-dihydroxydihydrothymine from the DNA of Micrococcus radiodurans

    International Nuclear Information System (INIS)

    Targovnik, H.S.; Hariharan, P.V.

    1980-01-01

    One of the major ionizing radiation products, 5,6-dihydroxydihydrothymine (thymine glycol), was measured in the DNA of Micrococcus radiodurans following exposure of cells to 6.8-MeV electrons or 254-nm ultraviolet light. Removal of 5,6-dihydroxydihydrothymine was measured in both an ionizing radiation-sensitive strain (262) and a highly radioresistant strain (the wild type W + ) of Micrococcus radiodurans. Within 30 min of incubation (33 0 C) following exposure to ultraviolet light (2400 J/m 2 ) approximately 60% of the thymine glycols were excised, whereas in the case of ionizing radiation (250 krad) only 35% were removed from the cellular DNA of the wild-type strain. In contrast less than 50% of the thymine glycols were excised from the sensitive strain. The amount of DNA degradation induced by radiation was less than 10% in both strains. The results suggest a possible correlation between reduced excision repair of base damage and increased radiation sensitivity

  19. Characterization and safety evaluation of a Deinococcus member as feed additive for hens.

    Science.gov (United States)

    Wu, Szu-Yin; Li, I-Chen; Lin, Yi-Chin; Chen, Chin-Chu

    2016-04-01

    As previous studies mainly focus on understanding the mechanisms of radioresistance in Deinococcus bacteria, the present study aimed at characterizing and verifying the safety use of the GKB-Aid 1995 strain, a member of the radiation-resistant bacterial genus Deinococcus, as an ingredient in feed supplements. Using Vitek 2 system and 16S rRNA gene sequencing, GKB-Aid 1995 most resembles Deinococcus grandis. The Ames test, in vitro chromosomal test, in vivo micronucleus test and acute toxicity test were performed subsequently for its safety evaluation. As there is a possibility that the pigment of GKB-Aid 1995 can pass from feed to eggs intended for human consumption, an acute toxicity test was also carried out in pigmented egg yolk. The results confirmed that GKB-Aid 1995 was non-genotoxic in three genotoxicity experiments, and the LD50 of GKB-Aid 1995 and the pigmented egg yolk in ICR mice was greater than 10 and 12 g kg(-1) body weight, respectively. Overall, these data indicate that GKB-Aid 1995 is a non-toxic substance with no genotoxicity and is therefore safe to be used as a feed supplement or feed additive. This study suggests there is potential in developing GKB-Aid 1995 as an animal feed additive intended to enhance yolk coloration to meet the demand of consumers. Copyright © 2016 Elsevier Inc. All rights reserved.

  20. Studies on Post-Irradiation DNA Degradation in Micrococcus Radiodurans, Strain RII51

    DEFF Research Database (Denmark)

    Auda, H.; Emborg, C.

    1973-01-01

    The influence of irradiation condition on post-irradiation DNA degradation was studied in a radiation resistant mutant of M. radiodurans, strain ${\\rm R}_{{\\rm II}}5$. After irradiation with 1 Mrad or higher more DNA is degraded in cells irradiated in wet condition than in cells irradiated with t...

  1. Deinococcus hibisci sp. nov., isolated from rhizosphere of Hibiscus syriacus L. (mugunghwa flower).

    Science.gov (United States)

    Moya, Gabriela; Yan, Zheng-Fei; Chu, Dong-Hun; Won, KyungHwa; Yang, Jung-Eun; Wang, Qi-Jun; Kook, Moo-Chang; Yi, Tae-Hoo

    2018-01-01

    A Gram-stain-positive, pink-pigmented, coccus-shaped, strictly aerobic, non-motile bacterium, strain THG-AG1.5 T , was isolated from rhizosphere of Hibiscus syriacus L. (Mugunghwa flower) located in Kyung Hee University, Yongin, Gyeonggi, Republic of Korea. The isolated strain grew optimally at 25-30 °C, at pH 6.0-7.5 and in the presence of additional 0-1.5 % (w/v) NaCl. Strain THG-AG1.5 T exhibited tolerance to UV radiation (>1500 J m -2 ) and to gamma radiation (>12 kGy). Based on 16S rRNA gene sequence comparisons, strain THG-AG1.5 T was closely related to Deinococcus daejeonensis MJ27 T (98.03 %), Deinococcus radiotolerans C1 T (97.61 %) and Deinococcus grandis DSM 3963 T (97.32 %). The genomic DNA G+C content of strain THG-AG1.5 T was 74.8 mol%. The DNA-DNA hybridization values between strain THG-AG1.5 T and its closest phylogenetically neighbours were below 63.0 %. The peptidoglycan amino acids were alanine, valine, glutamic acid, glycine, ornithine, lysine and aspartic acid. Strain THG-AG1.5 T contained ribose, mannose and glucose as whole-cell-wall sugars and menaquinone-8 (MK-8) as the only isoprenoid quinone. The major component in the polyamine pattern was spermidine. The major polar lipids of strain THG-AG1.5 T were a phosphoglycolipid, six unidentified glycolipids and an unidentified aminophospholipid. The major fatty acids were identified as iso-C15 : 0, C15 : 1ω6c, C16 : 0, iso-C17 : 0, C17 : 0, C18 : 0 and summed feature 3. On the basis of our polyphasic taxonomy study, strain THG-AG1.5 T represents a novel species within the genus Deinococcus, for which the name Deinococcushibisci sp. nov. is proposed. The type strain is THG-AG1.5 T (=KACC 18850 T =CCTCC AB 2016078 T ).

  2. Catalyst of D. radiodurans LexA protein and its induced catalysis at alkaline pH activated by RecA

    International Nuclear Information System (INIS)

    Kong Xiangrong; Liu Fenju; Su Liaoyuan

    2003-01-01

    It is to study the catalytic reaction of LexA at alkaline pH. It has been observed that reaction has taken place under two conditions of D. radiodurans and LexA. Methods: The method of SDS polypropylene amine was adopted to make dyeing with R-250. Results: The result showed that there were no reactions when LexA protein turned to be at pH 7.0 and pH 8.0, the entire LexA protein was decreased a little at pH 9.0, while at pH 10.0, LexA protein started to decompose greatly, the fractions of protein can be seen obviously in the electrophoresis belt. Conclusion: The D. radiodurans and LexA protein will automatically drop at 37 degree C when D radiodurans LexA is at higher pH value, and its dependence on alkaline pH conditions reflects that the catalytic needs to be activated by the reaction of de- pH indicator of LexA protein ionization

  3. Radioprotection in E. coli by an agent from M. radiodurans

    Energy Technology Data Exchange (ETDEWEB)

    Goldstein, L S; Gersten, D M; Bruce, A K [State Univ. of New York, Buffalo (USA). Dept. of Biology

    1978-10-01

    An agent extracted from the radioresistant bacterium M. radiodurans was found to protect several strains of E. coli from X-radiation. Optimal radioprotection was observed when the repair-proficient B/r strain was irradiated in the presence of the agent under hypoxic conditions. It is proposed that this agent acts to modify damage incurred in the presence of reduced oxygen concentrations so that this damage might be subsequently repaired.

  4. Loss of characteristic radiation resistance by mutation of Micrococcus radiodurans

    International Nuclear Information System (INIS)

    Kitayama, S.; Matusyama, A.

    1975-01-01

    The exceptional radioresistance of M. radiodurans was lost by a mutation, and the isolated mutant, KH840, had almost the same radiosensitivity as E. coli K12 AB1157 or B/r. DNA-strand scissions in this mutant were rejoined partly during post-irradiation incubation. Reduced DNA polymerizing activity and extensive degradation of the product was observed in vitro in the crude extract from the sensitive strain. The lower repair capability is not accompanied by the reduced transformation frequency

  5. Loss of characteristic radiation resistance by mutation of Micrococcus radiodurans

    Energy Technology Data Exchange (ETDEWEB)

    Kitayama, S; Matusyama, A [Institute of Physical and Chemical Research, Wako, Saitama (Japan)

    1975-09-01

    The exceptional radioresistance of M. radiodurans was lost by a mutation, and the isolated mutant, KH840, had almost the same radiosensitivity as E. coli K12 AB1157 or B/r. DNA-strand scissions in this mutant were rejoined partly during post-irradiation incubation. Reduced DNA polymerizing activity and extensive degradation of the product was observed in vitro in the crude extract from the sensitive strain. The lower repair capability is not accompanied by the reduced transformation frequency.

  6. DNA-membrane complex restoration in Micrococcus radiodurans after X-irradiation: relation to repair, DNA synthesis and DNA degradation

    Energy Technology Data Exchange (ETDEWEB)

    Dardalhon-Samsonoff, M; Averbeck, D [Institut du Radium, 75 - Paris (France). Lab. Curie

    1980-07-01

    The DNA-membrane complex in Micrococcus radiodurans was shown to be essentially constituted of proteins, lipids and DNA. The complex was dissociated immediately after X-irradiation of cells and restored during post-incubation in complete medium. In X-irradiated protoplasts some DNA remained associated with the complex. Restoration of the complex during post-incubation was only seen in a medium favouring DNA polymerase and ligase activities. Under this condition no DNA synthesis occurred, suggesting that complex restoration may involve ligase activity. The complex restoration in the wild type and the X-ray sensitive mutant UV17 of M. radiodurans was strictly dependent on the X-ray dose. It was correlated with survival and DNA degradation but always preceded the onset of DNA synthesis after X-irradiation. At the same dose the complex restoration was about 2 fold lower in mutant than in wild type cells indicating that the restoration of the complex is related to repair capacity. The results are consistent with the idea that the complex protects X-irradiated DNA of M. radiodurans from further breakdown and, subsequently, permits DNA synthesis and repair to occur.

  7. Development of application technology of radiation-resistant microorganism

    International Nuclear Information System (INIS)

    Kim, Dong Ho; Lim, Sang Yong; Joe, Min Ho; Jung, Jin Woo; Jung, Sun Wook; Song, Du Sup; Choi, Young Ji

    2009-02-01

    The scope of the project is divided into of three parts; (i) to define the survival strategy of radiation-resistant microbes, especially Deinococcus (ii) acquisition of gene resources encoding the novel protein and related with the production of functional materials (iii) development of control technology against radiation-resistant microbes. To this aim, first, the whole transcriptional response of the D. radiodurans strain haboring pprI mutation, which plays an important role in radiation resistance, was analyzed by cDNA microarray. The anti-oxidant activity of the major carotenoid of D. radiodurans, deinoxanthin, was analyzed and the strain was constructed, in which the gene necessary for bio- synthesis of deinoxanthin is deleted. The response to cadmium of D. radiodurans was also investigated through cDNA microarray analysis. Radiogenic therapy, one of the cancer treatments, is designed to use radiation-inducible gene for the treatment. To develop the gene-transfer vehicle for radiogenic therapy, we have investigated the virulence mechanism of Salmonella, which is tumor-targeting bacteria and studied the synergistic effect of some anti-cancer agents on radiation treatment for cancer. Finally, we confirmed that irradiation could decompose a fungus toxin, patulin, into various harmless by-products

  8. Development of application technology of radiation-resistant microorganism

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Dong Ho; Lim, Sang Yong; Joe, Min Ho; Jung, Jin Woo; Jung, Sun Wook; Song, Du Sup; Choi, Young Ji [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2009-02-15

    The scope of the project is divided into of three parts; (i) to define the survival strategy of radiation-resistant microbes, especially Deinococcus (ii) acquisition of gene resources encoding the novel protein and related with the production of functional materials (iii) development of control technology against radiation-resistant microbes. To this aim, first, the whole transcriptional response of the D. radiodurans strain haboring pprI mutation, which plays an important role in radiation resistance, was analyzed by cDNA microarray. The anti-oxidant activity of the major carotenoid of D. radiodurans, deinoxanthin, was analyzed and the strain was constructed, in which the gene necessary for bio- synthesis of deinoxanthin is deleted. The response to cadmium of D. radiodurans was also investigated through cDNA microarray analysis. Radiogenic therapy, one of the cancer treatments, is designed to use radiation-inducible gene for the treatment. To develop the gene-transfer vehicle for radiogenic therapy, we have investigated the virulence mechanism of Salmonella, which is tumor-targeting bacteria and studied the synergistic effect of some anti-cancer agents on radiation treatment for cancer. Finally, we confirmed that irradiation could decompose a fungus toxin, patulin, into various harmless by-products.

  9. Validation of a homology model of Mycobacterium tuberculosis DXS: rationalization of observed activities of thiamine derivatives as potent inhibitors of two orthologues of DXS.

    Science.gov (United States)

    Masini, T; Lacy, B; Monjas, L; Hawksley, D; de Voogd, A R; Illarionov, B; Iqbal, A; Leeper, F J; Fischer, M; Kontoyianni, M; Hirsch, A K H

    2015-12-14

    The enzyme DXS catalyzes the first, rate-limiting step of the 2-C-methyl-d-erythritol-4-phosphate (MEP, 1) pathway using thiamine diphosphate (ThDP) as cofactor; the DXS-catalyzed reaction constitutes also the first step in vitamin B1 and B6 metabolism in bacteria. DXS is the least studied among the enzymes of this pathway in terms of crystallographic information, with only one complete crystal structure deposited in the Protein Data Bank (Deinococcus radiodurans DXS, PDB: ). We synthesized a series of thiamine and ThDP derivatives and tested them for their biochemical activity against two DXS orthologues, namely D. radiodurans DXS and Mycobacterium tuberculosis DXS. These experimental results, combined with advanced docking studies, led to the development and validation of a homology model of M. tuberculosis DXS, which, in turn, will guide medicinal chemists in rationally designing potential inhibitors for M. tuberculosis DXS.

  10. Epigenetic changes of DNA repair genes in cancer

    OpenAIRE

    Lahtz, Christoph; Pfeifer, Gerd P.

    2011-01-01

    ‘Every Hour Hurts, The Last One Kills'. That is an old saying about getting old. Every day, thousands of DNA damaging events take place in each cell of our body, but efficient DNA repair systems have evolved to prevent that. However, our DNA repair system and that of most other organisms are not as perfect as that of Deinococcus radiodurans, for example, which is able to repair massive amounts of DNA damage at one time. In many instances, accumulation of DNA damage has been linked to cancer, ...

  11. Effect of cordycepin(3'-deoxyadenosine) on excision repair of 5,6-dihydroxy-dihydrothymine-type products from the DNA of Micrococcus radiodurans

    International Nuclear Information System (INIS)

    Patil, M.S.; Tundo, V.J.; Locher, S.E.; Hariharan, P.V.

    1983-01-01

    Cordycepin(3'-deoxyadenosine), a nucleoside analog, has been shown to enhance radiation-induced cell killing. In an effort to elucidate the possible mechanism for enhancement of cell killing, the effect of cordycepin on the excision repair of radiation-induced 5,6-dihydroxy-dihydrothymine-type (t') products from the DNA of wild type Micrococcus radiodurans was investigated. The capacity of M. radiodurans to excise nondimeric (t') products from its DNA was significantly impaired after cordycepin treatment. The results suggest that the increased radiation sensitivity of cordycepin-treated cells could be due to alterations in cellular processes that repair DNA damage

  12. Studies on the Mechanism of Radiation Resistance in Micrococcus Radiodurans and its Sensitization

    Energy Technology Data Exchange (ETDEWEB)

    Kitayama, S.; Matsuyama, A. [Radiobiology Laboratory, Institute of Physical and Chemical Research, Wako-shi, Saitama-ken (Japan)

    1978-06-15

    Efficient and accurate repair of radiation-induced lesions in M. radiodurans was investigated as to the cause of its extreme radioresistance. The cells were made permeable to deoxyribonucleoside triphosphate by treatment with non-ionic detergent, Triton X-100. After irradiation with 2 krad gamma rays more than 80% of the single-strand scissions were rejoined in the permeable cells within 10 min at 37 Degree-Sign C. This fast repair process requires the presence of deoxyribonucleoside triphosphates and NAD. However, rejoining of DNA strand scission was incomplete after prolonged incubation in the permeable cells. This suggests that alternate repair reaction(s) is necessary for complete recovery. The other type of radiation lesion was found by postirradiation incubation at non-permissive temperature, which markedly sensitizes this bacterium to radiation. Postincubation at this temperature also sensitizes the cells to chemicals that damage DNA. The extreme radioresistance of this bacterium was also lost by mutation and an isolated radiosensitive mutant showed almost the same radiosensitivity as E. coli K12 or B/r. These results are discussed in connection with the extreme radioresistance of M. radiodurans. (author)

  13. Studies on the mechanism of radiation resistance in Micrococcus radiodurans and its sensitization

    International Nuclear Information System (INIS)

    Kitayama, S.; Matsuyama, A.

    1978-01-01

    Efficient and accurate repair of radiation-induced lesions in M. radiodurans was investigated as to the cause of its extreme radioresistance. The cells were made permeable to deoxyribonucleoside triphosphate by treatment with non-ionic detergent, Triton X-100. After irradiation with 2 krad gamma rays more than 80% of the single-strand scissions were rejoined in the permeable cells within 10 min at 37 0 C. This fast repair process requires the presence of deoxyribonucleoside triphosphates and NAD. However, rejoining of DNA strand scission was incomplete after prolonged incubation in the permeable cells. This suggests that alternate repair reaction(s) is necessary for complete recovery. The other type of radiation lesion was found by post-irradiation incubation at non-permissive temperature, which markedly sensitizes this bacterium to radiation. Postincubation at this temperature also sensitizes the cells to chemicals that damage DNA. The extreme radioresistance of this bacterium was also lost by mutation and an isolated radiosensitive mutant showed almost the same radiosensitivity as E. coli K12 or B/r. These results are discussed in connection with the extreme radioresistance of M. radiodurans. (author)

  14. Dormancy in Deinococcus sp. UDEC-P1 as a survival strategy to escape from deleterious effects of carbon starvation and temperature.

    Science.gov (United States)

    Guerra, Matías; González, Karina; González, Carlos; Parra, Boris; Martínez, Miguel

    2015-09-01

    Dormancy is characterized by low metabolism and absence of protein synthesis and cellular division enabling bacterial cells to survive under stress. The aim was to determine if carbon starvation and low temperature are factors that modify the proportion of dormant/active cells in Deinococcus sp. UDEC-P1. By flow cytometry, RedoxSensor Green (RSG) was used to quantify metabolic activity and Propidium Iodide (PI) to evaluate membrane integrity in order to determine the percentage of dormant cells. Cell size and morphology were determined using scanning electronic microscopy. Under carbon starvation at 30°C, Deinococcus sp. UDEC-P1 increased its proportion of dormant cells from 0.1% to 20%, decreased the count of culturable cells and average cell volume decreased 7.1 times. At 4°C, however, the proportion of dormant cells increased only to 6%, without a change in the count of culturable cells and an average cellular volume decrease of 4.1 times and 3% of the dormant cells were able to be awakened. Results indicate a greater proportion of dormant Deinococcus sp. UDEC-P1 cells at 30ºC and it suggests that carbon starvation is more deleterious condition at 30ºC than 4ºC. For this reason Deinococcus sp. UDEC-P1 cells are more likely to enter into dormancy at higher temperature as a strategy to survive. Copyright© by the Spanish Society for Microbiology and Institute for Catalan Studies.

  15. Nucleotide fluctuation of radiation-resistant Halobacterium sp. NRC-1 single-stranded DNA-binding protein (RPA) genes

    Science.gov (United States)

    Holden, Todd; Tremberger, G., Jr.; Cheung, E.; Subramaniam, R.; Gadura, N.; Schneider, P.; Sullivan, R.; Flamholz, A.; Lieberman, D.; Cheung, T. D.

    2009-08-01

    The Single-Stranded DNA-Binding Protein (RPA) Genes in gamma ray radiation-resistant halophilic archaeon Halobacterium sp. NRC-1 were analyzed in terms of their nucleotide fluctuations. In an ATCG sequence, each base was assigned a number equal to its atomic number. The resulting numerical sequence was the basis of the statistical analysis in this study. Fractal analysis using the Higuchi method gave fractal dimensions of 2.04 and 2.06 for the gene sequences VNG2160 and VNG2162, respectively. The 16S rRNA sequence has a fractal dimension of 1.99. The di-nucleotide Shannon entropy values were found to be negatively correlated with the observed fractal dimensions (R2~ 0.992, N=3). Inclusion of Deinococcus radiodurans Rad-A in the regression analysis decreases the R2 slightly to 0.98 (N=4). A third VNG2163 RPA gene of unknown function but with upregulation activity under irradiation was found to have a fractal dimension of 2.05 and a Shannon entropy of 3.77 bits. The above results are similar to those found in bacterial Deinococcus radiodurans and suggest that their high radiation resistance property would have favored selection of CG di-nucleotide pairs. The two transcription factors TbpD (VNG7114) and TfbA (VNG 2184) were also studied. Using VNG7114, VNG2184, and VNG2163; the regression analysis of fractal dimension versus Shannon entropy shows that R2 ~ 0.997 for N =3. The VNG2163 unknown function may be related to the pathways with transcriptions closely regulated to sequences VNG7114 and VNG2184.

  16. A New Perspective on Radiation Resistance Based on Deinococcus radiodurans

    Science.gov (United States)

    2009-03-01

    tolerate 3,000–5000 Gy, but are rendered sterile. As a haploid, the basidiomycete fungus Ustilago maydis carries a single set of chromosomes per...salinarum NRC-1. Environ. Microbiol. 5 Jan 2009 (doi:10.1111/j.1462-2920.2008.01828.x). 21. Chan, H. L. et al. Proteomic analysis of UVC irradiation

  17. Isolation and identification of a novel radio-resistant strain

    International Nuclear Information System (INIS)

    Zhang Zhidong; Mao Jun; Wang Wei; Tang Qiyong; Shi Yuhu

    2008-01-01

    A novel radio-resistant strain named RL2 was studied polyphasically, which was isolated from the soils in the Gurban-Tunggut Desert, Xinjiang. The strain is Gam-positive, sphere-shaped and pink pigmented; The DNA (G+C) contents of RL2 is 71.62mo1%; The 16S rDNA genes of RL2 and D. radiodurans type strain DSM20539 shows a high level of similarity (97.2%). According to phenotypic characteristics and phylogenetic analysis, it can be suggested that the strain RL2 has been identified as Deinococcus. sp and it may be a novel species. (authors)

  18. DE-FG02-04ER63746 FinalTechnicalReport

    Energy Technology Data Exchange (ETDEWEB)

    Lidstrom, M.E.

    2009-09-05

    This is the final technical report for a project involving the study of stress response systems in the radiation-resistant bacterium, Deinococcus radiodurans. Three stresses of importance for a mixed waste treatment strain were studied, heat shock, solvent shock, and phosphate starvation. In each case, specific genes involved in the ability to survive the stress were identified using a systems biology approach, and analysis of mutants was used to understand mechanisms. This study has led to increased understanding of the ways in which a potential treatment strain could be manipulated to survive multiple stresses for treatment of mixed wastes.

  19. Repair of the double-strand breaks produced by /sup 125/I disintegrations in the DNA of micrococcus radiodurans

    Energy Technology Data Exchange (ETDEWEB)

    Myers, D K [Atomic Energy of Canada Ltd., Chalk River, Ontario. Chalk River Nuclear Labs.

    1978-01-01

    Wild-type M. radiodurans and two radiosensitive mutants were used to study the lethal effects of /sup 125/I disintegrations in their DNA. The relative sensitivities of these three strains to inactivation by ..gamma..-radiation were reflected in their relative sensitivities to inactivation by /sup 125/I decay. The number of double-strand (ds) breaks in the DNA appeared to be similar at levels of ..gamma..-radiation and of /sup 125/I decay that reduced survival to 10%. All three strains of M. radiodurans rapidly repaired ds breaks produced in their DNA by either ..gamma..-radiation or /sup 125/I disintegrations. If one ds break per cell is a lethal event (Krisch. et al., 1975), cells of the three strains tested would die when they had left unrepaired one ds break out of an initial 45, 600 or 1800 ds breaks per single cell.

  20. Rescue of Mitomycin C- or Psoralen-Inactivated Micrococcus Radiodurans by Additional Exposure to Radiation or Alkylating Agents

    DEFF Research Database (Denmark)

    Hansen, M. Trier

    1982-01-01

    The processing of damaged DNA was altered in a mitomycin C-sensitive mutant (mtcA) of Micrococcus radiodurans. Even though the mutant retained resistance to 254-nm UV radiation, it did not, in contrast to the wild-type strain, show any excessive DNA degradation or cell death when incubated...

  1. Bacteriophytochrome controls carotenoid-independent response to photodynamic stress in a non-photosynthetic rhizobacterium, Azospirillum brasilense Sp7.

    Science.gov (United States)

    Kumar, Santosh; Kateriya, Suneel; Singh, Vijay Shankar; Tanwar, Meenakshi; Agarwal, Shweta; Singh, Hina; Khurana, Jitendra Paul; Amla, Devinder Vijay; Tripathi, Anil Kumar

    2012-01-01

    Ever since the discovery of the role of bacteriophytochrome (BphP) in inducing carotenoid synthesis in Deinococcus radiodurans in response to light the role of BphPs in other non-photosynthetic bacteria is not clear yet. Azospirillum brasilense, a non-photosynthetic rhizobacterium, harbours a pair of BphPs out of which AbBphP1 is a homolog of AtBphP1 of Agrobacterium tumefaciens. By overexpression, purification, biochemical and spectral characterization we have shown that AbBphP1 is a photochromic bacteriophytochrome. Phenotypic study of the ΔAbBphP1 mutant showed that it is required for the survival of A. brasilense on minimal medium under red light. The mutant also showed reduced chemotaxis towards dicarboxylates and increased sensitivity to the photooxidative stress. Unlike D. radiodurans, AbBphP1 was not involved in controlling carotenoid synthesis. Proteome analysis of the ΔAbBphP1 indicated that AbBphP1 is involved in inducing a cellular response that enables A. brasilense in regenerating proteins that might be damaged due to photodynamic stress.

  2. Plant breeding by using radiation mutation - Development of radiation indicator plants by molecular breeding

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Jang Ryol; Kwak, Sang Soo; Kwon, Seok Yoon [Korea Research Institute of Bioscience and Biotechnology, Taejon (Korea)

    2000-04-01

    - tSOD1, cytosolic CuZnSOD cDNA was cloned from tobacco cDNA library by PCR. To develop the under-producing the transgenic plants, the vectors were constructed using by antisense and co-supressing technology. The transgenic tobacco plants were confirmed that over 60% of kanamycin-resistant plants were introduced the foreign gene by PCR and transformed one copy through Southern blot analysis. - In an attempt to identify marker genes for gamma irradiation of plants, expression patterns of diverse genes upon gamma irradiation of young tobacco plants were investigated. With the knowledge of distinctive expression patterns of diverse genes, irradiation-indicating marker plants could be developed by engineering and monitoring multiple radiation-responsive genes. Additionally, a gamma irradiation-responsive NtTMK1 receptor-like kinase gene was molecular biologically characterized. -Uranium reductase gene (Cytochrome C3) and radiation resistance gene (recA) have been cloned from Desulfovibrio and Deinococcus radiodurans. -Two plant transformation vectors (pCYC3 and pDrecA) have been constructed. - Tobacco transgenic plants of have been obtained. 52 refs., 5 figs. (Author)

  3. Detection of DNA strand breaks in mammalian cells using the radioresistant bacterium PprA protein

    International Nuclear Information System (INIS)

    Satoh, Katsuya; Wada, Seiichi; Narumi, Issay; Kikuchi, Masahiro; Funayama, Tomoo; Kobayashi, Yasuhiko

    2003-01-01

    We have previously found that the PprA protein from Deinococcus radiodurans possesses ability to recognize DNA carrying strand breaks. In the present study, we attempted to visualize radiation-induced DNA strand breaks with PprA protein using immunofluorescence technique to elucidate the DNA damage response mechanism in mammalian cultured cells. As a result, colocalization of Cy2 and DAPI fluorescent signals was observed. This observation suggests that DNA strand breaks in the nucleus of CHO-K1 cells were effectively detected using the PprA protein. The amount of DNA strand breaks (integrated density of Cy2 fluorescent signals) was increased with the increase in the radiation dose. (author)

  4. Extreme Ionizing-Radiation-Resistant Bacterium

    Science.gov (United States)

    Vaishampayan, Parag A.; Venkateswaran, Kasthuri J.; Schwendner, Petra

    2013-01-01

    There is a growing concern that desiccation and extreme radiation-resistant, non-spore-forming microorganisms associated with spacecraft surfaces can withstand space environmental conditions and subsequent proliferation on another solar body. Such forward contamination would jeopardize future life detection or sample return technologies. The prime focus of NASA s planetary protection efforts is the development of strategies for inactivating resistance-bearing micro-organisms. Eradi cation techniques can be designed to target resistance-conferring microbial populations by first identifying and understanding their physiologic and biochemical capabilities that confers its elevated tolerance (as is being studied in Deinococcus phoenicis, as a result of this description). Furthermore, hospitals, food, and government agencies frequently use biological indicators to ensure the efficacy of a wide range of radiation-based sterilization processes. Due to their resistance to a variety of perturbations, the nonspore forming D. phoenicis may be a more appropriate biological indicator than those currently in use. The high flux of cosmic rays during space travel and onto the unshielded surface of Mars poses a significant hazard to the survival of microbial life. Thus, radiation-resistant microorganisms are of particular concern that can survive extreme radiation, desiccation, and low temperatures experienced during space travel. Spore-forming bacteria, a common inhabitant of spacecraft assembly facilities, are known to tolerate these extreme conditions. Since the Viking era, spores have been utilized to assess the degree and level of microbiological contamination on spacecraft and their associated spacecraft assembly facilities. Members of the non-sporeforming bacterial community such as Deinococcus radiodurans can survive acute exposures to ionizing radiation (5 kGy), ultraviolet light (1 kJ/m2), and desiccation (years). These resistive phenotypes of Deinococcus enhance the

  5. Origin of cell surface proteins released from Micrococcus radiodurans by ionizing radiation

    International Nuclear Information System (INIS)

    Mitchel, R.E.J.

    1975-01-01

    The exposure of Micrococcus radiodurans to sublethal doses of ionizing radiation causes the release of certain proteins into the surrounding medium. As estimated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, these proteins range from approximately 20,000 to 125,000 daltons. At least some of the proteins, including an exonuclease, have a surface location and appear to originate from the lipid-rich midwall layer. The exonuclease has two functionally distinct locations, one with its active site available to external substrate and a second with the active site masked from the exterior. Ionizing radiation releases both the masked and unmasked activity into the surrounding medium

  6. Effects of oxygen during γ-irradiation of Micrococcus radiodurans

    International Nuclear Information System (INIS)

    Myers, D.K.; Johnson, L.D.

    1977-01-01

    A study has been made of the effects of oxygen on the yield of double strand breaks in the DNA of Micrococcus radiodurans, and of the relation of these effects to cell death. The o.e.r. values for cell survival were considerably smaller than those for the yield of double strand breaks, although they showed similar trends after irradiation in different media. The o.e.r. values for the inhibition of post-irradiation enzymatic repair were similar to those for cell survival. The o.e.r. for radiation-induced breaks in DNA therefore seems to depend on radiochemical reactions that are occurring during irradiation rather than on a preferential enzymatic repair of those strand breaks that are produced by anoxic irradiation. Cell survival depends less on the number of double strand breaks produced than on the ability of the cell to repair the double strand breaks. The maximum yield of double strand breaks after oxic γ-irradiation was approximately 1.7 breaks/krad/10 10 Daltons, corresponding to 1 break per 610 eV. (U.K.)

  7. Effects of oxygen during. gamma. irradiation of Micrococcus radiodurans

    Energy Technology Data Exchange (ETDEWEB)

    Myers, D K; Johnson, L D [Atomic Energy of Canada Ltd., Chalk River, Ontario. Chalk River Nuclear Labs.

    1977-09-01

    A study has been made of the effects of oxygen on the yield of double strand breaks in the DNA of Micrococcus radiodurans, and of the relation of these effects to cell death. The OER values for cell survival were considerably smaller than those for the yield of double strand breaks, although they showed similar trends after irradiation in different media. The OER values for the inhibition of post-irradiation enzymatic repair were similar to those for cell survival. The OER for radiation-induced breaks in DNA therefore seems to depend on radiochemical reactions that are occurring during irradiation rather than on a preferential enzymatic repair of those strand breaks that are produced by anoxic irradiation. Cell survival depends less on the number of double strand breaks produced than on the ability of the cell to repair the double strand breaks. The maximum yield of double strand breaks after oxic ..gamma.. irradiation was approximately 1.7 breaks/krad/10/sup 10/Daltons, corresponding to 1 break per 610 eV.

  8. Radiation-induced enhancement of enzymatic cell lysis of Micrococcus radiodurans

    International Nuclear Information System (INIS)

    Watanabe, H.; Takehisa, M.; Iizuka, H.

    1981-01-01

    The intact cells of M. radiodurans were rendered sensitive to the action of lytic enzyme (P2-2 enzyme) by irradiation. The radiation-induced enhancement of cell lysis with P2-2 enzyme was completely prevented by the addition of t-butanol and irradiation at liquid nitrogen temperature. These results indicate that the enhancement is due to indirect action resulting from OH radicals. Cell lysis by lysozyme was enhanced only when the cells were irradiated under N 2 O. The enhancement of cell lysis with lysozyme was also prevented by adding alcohols. On the other hand, when lipid components in cells were removed by extraction with n-butanol, the radiation-induced enhancement of cell lysis with P2-2 enzyme and lysozyme was not observed. From these results it is concluded that the enhancement of enzymatic cell lysis by irradiation is attributable to alteration in the lipid-rich layer of the cell wall caused by OH radicals

  9. Radiation-induced enhancement of enzymatic cell lysis of Micrococcus radiodurans

    Energy Technology Data Exchange (ETDEWEB)

    Watanabe, H.; Takehisa, M. [Japan Atomic Energy Research Inst., Takasaki, Gunma, Takasaki Radiation Chemistry Research Establishment (Japan); Iizuka, H.

    1981-10-15

    The intact cells of M. radiodurans were rendered sensitive to the action of lytic enzyme (P2-2 enzyme) by irradiation. The radiation-induced enhancement of cell lysis with P2-2 enzyme was completely prevented by the addition of t-butanol and irradiation at liquid nitrogen temperature. These results indicate that the enhancement is due to indirect action resulting from OH radicals. Cell lysis by lysozyme was enhanced only when the cells were irradiated under N{sub 2}O. The enhancement of cell lysis with lysozyme was also prevented by adding alcohols. On the other hand, when lipid components in cells were removed by extraction with n-butanol, the radiation-induced enhancement of cell lysis with P2-2 enzyme and lysozyme was not observed. From these results it is concluded that the enhancement of enzymatic cell lysis by irradiation is attributable to alteration in the lipid-rich layer of the cell wall caused by OH radicals.

  10. Methanosarcina acetivorans 16S rRNA and transcription factor nucleotide fluctuation with implications in exobiology and pathology

    Science.gov (United States)

    Holden, Todd; Tremberger, G., Jr.; Cheung, E.; Subramaniam, R.; Sullivan, R.; Schneider, P.; Flamholz, A.; Marchese, P.; Hiciano, O.; Yao, H.; Lieberman, D.; Cheung, T.

    2008-08-01

    Cultures of the methane-producing archaea Methanosarcina, have recently been isolated from Alaskan sediments. It has been proposed that methanogens are strong candidates for exobiological life in extreme conditions. The spatial environmental gradients, such as those associated with the polygons on Mars' surface, could have been produced by past methanogenesis activity. The 16S rRNA gene has been used routinely to classify phenotypes. Using the fractal dimension of nucleotide fluctuation, a comparative study of the 16S rRNA nucleotide fluctuation in Methanosarcina acetivorans C2A, Deinococcus radiodurans, and E. coli was conducted. The results suggest that Methanosarcina acetivorans has the lowest fractal dimension, consistent with its ancestral position in evolution. Variation in fluctuation complexity was also detected in the transcription factors. The transcription factor B (TFB) was found to have a higher fractal dimension as compared to transcription factor E (TFE), consistent with the fact that a single TFB in Methanosarcina acetivorans can code three different TATA box proteins. The average nucleotide pair-wise free energy of the DNA repair genes was found to be highest for Methanosarcina acetivorans, suggesting a relatively weak bonding, which is consistent with its low prevalence in pathology. Multitasking capacity comparison of type-I and type-II topoisomerases has been shown to correlate with fractal dimension using the methicillin-resistant strain MRSA 252. The analysis suggests that gene adaptation in a changing chemical environment can be measured in terms of bioinformatics. Given that the radiation resistant Deinococcus radiodurans is a strong candidate for an extraterrestrial origin and that the cold temperature Psychrobacter cryohalolentis K5 can function in Siberian permafrost, the fractal dimension comparison in this study suggests that a chemical resistant methanogen could exist in extremely cold conditions (such as that which existed on early

  11. Destruction of Raman biosignatures by ionising radiation and the implications for life detection on Mars.

    Science.gov (United States)

    Dartnell, Lewis R; Page, Kristian; Jorge-Villar, Susana E; Wright, Gary; Munshi, Tasnim; Scowen, Ian J; Ward, John M; Edwards, Howell G M

    2012-04-01

    Raman spectroscopy has proven to be a very effective approach for the detection of microorganisms colonising hostile environments on Earth. The ExoMars rover, due for launch in 2018, will carry a Raman laser spectrometer to analyse samples of the martian subsurface collected by the probe's 2-m drill in a search for similar biosignatures. The martian surface is unprotected from the flux of cosmic rays, an ionising radiation field that will degrade organic molecules and so diminish and distort the detectable Raman signature of potential martian microbial life. This study employs Raman spectroscopy to analyse samples of two model organisms, the cyanobacterium Synechocystis sp. PCC 6803 and the extremely radiation resistant polyextremophile Deinococcus radiodurans, that have been exposed to increasing doses of ionising radiation. The three most prominent peaks in the Raman spectra are from cellular carotenoids: deinoxanthin in D. radiodurans and β-carotene in Synechocystis. The degradative effect of ionising radiation is clearly seen, with significant diminishment of carotenoid spectral peak heights after 15 kGy and complete erasure of Raman biosignatures by 150 kGy of ionising radiation. The Raman signal of carotenoid in D. radiodurans diminishes more rapidly than that of Synechocystis, believed to be due to deinoxanthin acting as a superior scavenger of radiolytically produced reactive oxygen species, and so being destroyed more quickly than the less efficient antioxidant β-carotene. This study highlights the necessity for further experimental work on the manner and rate of degradation of Raman biosignatures by ionising radiation, as this is of prime importance for the successful detection of microbial life in the martian near subsurface.

  12. Identification and Characterization of uvrA, a DNA Repair Gene of Deinococcus radiodurans

    Science.gov (United States)

    1996-01-01

    alkylating agents , such as methyl-N-nitro~N~nitrosoguanidine(MNNG), N-methyl-N~ nitrosourea (MNU), and to a lesser extent methyl methanesulfonate (MMS...6,4) Photoproduct 17 c. Thymine Glycols and Cross-links 17 3. Ionizing Radiation Damage " 17 4. Chemical Damage 20 a. Alkylating Agents .20 b. Cross...Examples of base damage induced by ionizing radiation 19 6. Nucleotide centers in DNA that are most reactive to alkylating agents 21 7. Schematic

  13. DNA damage response in a radiation resistant bacterium Deinococcus radiodurans: a paradigm shift

    International Nuclear Information System (INIS)

    Misra, H.S.

    2015-01-01

    Deinococcusradiodurans is best known for its extraordinary resistance to gamma radiation with its D 10 12kGy, and several other DNA damaging agents including desiccation to less than 5% humidity and chemical xenotoxicants. An efficient DNA double strand break (DSB) repair and its ability to protect biomolecules from oxidative damage are a few mechanisms attributed to these phenotypes in this bacterium. Although it regulates its proteome and transcriptome in response to DNA damage for its growth and survival, it lacks LexA mediated classical SOS response mechanism. Since LexA mediated damages response mechanism is highly and perhaps only, characterized DNA damage response processes in prokaryotes, this bacterium keeps us guessing how it responds to extreme doses of DNA damage. Interestingly, this bacterium encodes a large number of eukaryotic type serine threonine/tyrosine protein kinases (eST/YPK), phosphatases and response regulators and roles of eST/YPKs in cellular response to DNA damage and cell cycle regulations are well established in eukaryotes. Here, we characterized an antioxidant and DNA damage inducible eST/YPK (RqkA) and established its role in extraordinary radioresistance and DSB repair in this bacterium. We identified native phosphoprotein substrates for this kinase and demonstrated the involvement of some of these proteins phosphorylation in the regulation of DSB repair and growth under radiation stress. Findings suggesting the possible existence of eST/YPK mediated DNA damage response mechanism as an alternate to classical SOS response in this prokaryote would be discussed. (author)

  14. Involvement of hydroxyl radicals in the release by ionizing radiation of a cell surface nuclease from Micorcoccus radiodurans

    International Nuclear Information System (INIS)

    Mitchel, R.E.J.

    1975-01-01

    The ionizing radiation-induced release of a surface exonuclease from Micrococcus radiodurans is to a large extent inhibited by the removal of water. Irradiation of a cell suspension saturated with O 2 (an effective aqueous electron and hydrogen atom scavenger) allows the same release as irradiation in the presence of N 2 . Ethanol (a good hydroxyl radical scavenger) protects the enzyme from release. These data suggest that hydroxyl radicals produced by the radiolysis of water are important releasing agents. Hydroxyl radicals produced by the ultraviolet decomposition of H 2 O 2 were effective in releasing the enzyme

  15. Microbial survival of space vacuum and extreme ultraviolet irradiation: strain isolation and analysis during a rocket flight.

    Science.gov (United States)

    Saffary, Roya; Nandakumar, Renu; Spencer, Dennis; Robb, Frank T; Davila, Joseph M; Swartz, Marvin; Ofman, Leon; Thomas, Roger J; DiRuggiero, Jocelyne

    2002-09-24

    We have recovered new isolates from hot springs, in Yellowstone National Park and the Kamchatka Peninsula, after gamma-irradiation and exposure to high vacuum (10(-6) Pa) of the water and sediment samples. The resistance to desiccation and ionizing radiation of one of the isolates, Bacillus sp. strain PS3D, was compared to that of the mesophilic bacterium, Deinococcus radiodurans, a species well known for its extraordinary resistance to desiccation and high doses of ionizing radiation. Survival of these two microorganisms was determined in real and simulated space conditions, including exposure to extreme UV radiation (10-100 nm) during a rocket flight. We found that up to 15 days of desiccation alone had little effect on the viability of either bacterium. In contrast, exposure to space vacuum ( approximately 10(-6) Pa) decreased cell survival by two and four orders of magnitude for Bacillus sp. strain PS3D and D. radiodurans, respectively. Simultaneous exposure to space vacuum and extreme UV radiation further decreased the survival of both organisms, compared to unirradiated controls. This is the first report on the isolated effect of extreme UV at 30 nm on cell survival. Extreme UV can only be transmitted through high vacuum, therefore its penetration into the cells may only be superficial, suggesting that in contrast to near UV, membrane proteins rather than DNA were damaged by the radiation.

  16. Epigenetic changes of DNA repair genes in cancer.

    Science.gov (United States)

    Lahtz, Christoph; Pfeifer, Gerd P

    2011-02-01

    'Every Hour Hurts, The Last One Kills'. That is an old saying about getting old. Every day, thousands of DNA damaging events take place in each cell of our body, but efficient DNA repair systems have evolved to prevent that. However, our DNA repair system and that of most other organisms are not as perfect as that of Deinococcus radiodurans, for example, which is able to repair massive amounts of DNA damage at one time. In many instances, accumulation of DNA damage has been linked to cancer, and genetic deficiencies in specific DNA repair genes are associated with tumor-prone phenotypes. In addition to mutations, which can be either inherited or somatically acquired, epigenetic silencing of DNA repair genes may promote tumorigenesis. This review will summarize current knowledge of the epigenetic inactivation of different DNA repair components in human cancer.

  17. Spectroelectrochemical insights into structural and redox properties of immobilized endonuclease III and its catalytically inactive mutant

    Science.gov (United States)

    Moe, Elin; Rollo, Filipe; Silveira, Célia M.; Sezer, Murat; Hildebrandt, Peter; Todorovic, Smilja

    2018-01-01

    Endonuclease III is a Fe-S containing bifunctional DNA glycosylase which is involved in the repair of oxidation damaged DNA. Here we employ surface enhanced IR spectroelectrochemistry and electrochemistry to study the enzyme from the highly radiation- and desiccation-resistant bacterium Deinococcus radiodurans (DrEndoIII2). The experiments are designed to shed more light onto specific parameters that are currently proposed to govern damage search and recognition by endonucleases III. We demonstrate that electrostatic interactions required for the redox activation of DrEndoIII2 may result in high electric fields that alter its structural and thermodynamic properties. Analysis of inactive DrEndoIII2 (K132A/D150A double mutant) interacting with undamaged DNA, and the active enzyme interacting with damaged DNA also indicate that the electron transfer is modulated by subtle differences in the protein-DNA complex.

  18. Deinococcus gobiensis cold shock protein improves salt stress tolerance of escherichia coli

    International Nuclear Information System (INIS)

    Jiang Shijie; Wang Jin; Yang Mingkun; Chen Ming; Zhang Wei; Luo Xuegang

    2013-01-01

    The Deinococcus gobiensis I-0, an extremely radiation-resistant bacterium, isolated from the Gobi, has superior resistance to abiotic stress (e.g radiation, oxidation, dehydration and so on). The two cold-shock proteins encoded by csp1 (Dgo_CA1136) and csp2 (Dgo_PA0041) were identified in the complete genome sequence of D. gobiensis. In this study, we showed that D. gobiensis Csp1 protected Escherichia coli cells against cold shock and other abiotic stresses such as salt and osmotic shocks. The quantitative real-time PCR assay shows that the expression of trehalose synthase (otsA, otsB) was up-regulated remarkably under salt stress in the csp1-expressing strain, while no difference in the expression of the genes involved in trehalose degradation (treB and treC). The results suggested that Csp1 caused the accumulation of the trehalose was a major feature for improving tolerance to salt stress in E. coli. (authors)

  19. Ionizing radiation damage in Micrococcus radiodurans cell wall: release of polysaccharide

    International Nuclear Information System (INIS)

    Mitchel, R.E.J.

    1976-01-01

    Sublethal 60 Co γ-irradiation of the bacterium Micrococcus radiodurans in aqueous suspension results in a loss of up to 6 percent of its cellular dry weight and 30 percent of its wet weight. In the process some specific cell wall polysaccharides, including a polymer of glucose and N-acylated glucosamine, are released into the surrounding medium. These polysaccharides appear to originate from a hydrophobic site in the middle, lipid-rich, cell wall layer. The damage to this layer which results in the release of these and other polymers may be due to a disruption of this hydrophobic site. The polysaccharide containing glucose and N-acylated glucosamine exists as a high molecular weight polymer in unirradiated cells, but irradiation causes some degradation prior to release. In a free state this polysaccharide is considerably less sensitive to radiolytic degradation than in a bound state. Free radicals generated from surrounding water by ionizing radiation initiate the release, hydroxyl radicals being the most important species. Oxygen protects the cell wall against loss of the polysaccharides, apparently by a mechanism which does not depend on the ability of O 2 to scavenge hydrogen atoms and aqueous electrons

  20. Characterizing the Catalytic Potential of Deinococcus, Arthrobacter and other Robust Bacteria in Contaminated Subsurface Environments of the Hanford Site

    Energy Technology Data Exchange (ETDEWEB)

    Daly, Michael J.

    2005-06-01

    Natural selection in highly radioactive waste sites may yield bacteria with favorable bioremediating characteristics. However, until recently the microbial ecology of such environments has remained unexplored because of the high costs and technical complexities associated with extracting and characterizing samples from such sites. We have examined the bacterial ecology within radioactive sediments from a high-level nuclear waste plume in the vadose zone on the DOE?s Hanford Site in south-central Washington state (Fredrickson et al, 2004). Manganese-dependent, radiation resistant bacteria have been isolated from this contaminated site including the highly Mn-dependent Deinococcus and Arthrobacter spp.

  1. High resistance of some oligotrophic bacteria to ionizing radiation

    International Nuclear Information System (INIS)

    Nikitin, D.I.; Tashtemirova, M.A.; Pitryuk, I.A.; Sorokin, V.V.; Oranskaya, M.S.; Nikitin, L.E.

    1994-01-01

    The resistance of seven cultures of eutrophic and oligotrophic bacteria to gamma radiation (at doses up to 360 Gy) was investigated. The bacteria under study were divided into three groups according to their survival ability after irradiation. Methylobacterium organophilum and open-quotes Pedodermatophilus halotoleransclose quotes (LD 50 = 270 Gy) were highly tolerant. By their tolerance, these organisms approached Deinococcus radiodurans. Aquatic ring-shaped (toroidal) bacteria Flectobacillus major and open-quotes Arcocella aquaticaclose quotes (LD 5 = 173 and 210 Gy, respectively) were moderately tolerant. Eutrophic Pseudomonas fluorescens and Escherichia coli (LD 50 = 43 and 38 Gy, respectively) were the most sensitive. X-ray microanalysis showed that in tolerant bacteria the intracellular content of potassium increased and the content of calcium decreased after irradiation. No changes in the element composition of the eutrophic bacterium E. coli were detected. Possible mechanisms of the resistance of oligotrophic bacteria to gamma radiation are discussed

  2. Irradiation of Microbes from Spent Nuclear Fuel Storage Pool Environments

    International Nuclear Information System (INIS)

    Breckenridge, C.R.; Watkins, C.S.; Bruhn, D.F.; Roberto, F.F.; Tsang, M.N.; Pinhero, P.J.; Brey, R.F.; Wright, R.N.; Windes, W.F.

    1999-01-01

    Microbes have been isolated and identified from spent nuclear fuel storage pools at the Idaho National Engineering and Environmental Laboratory (INEEL). Included among these are Corynebacterium aquaticum, Pseudomonas putida, Comamonas acidovorans, Gluconobacter cerinus, Micrococcus diversus, Rhodococcus rhodochrous, and two strains of sulfate-reducing bacteria (SRB). We examined the sensitivity of these microbes to a variety of total exposures of radiation generated by a 6-MeV linear accelerator (LINAC). The advantage of using a LINAC is that it provides a relatively quick screen of radiation tolerance. In the first set of experiments, we exposed each of the aforementioned microbes along with four additional microbes, pseudomonas aeruginosa, Micrococcus luteus, Escherchia coli, and Deinococcus radiodurans to exposures of 5 x 10 3 and 6 x 10 4 rad. All microbial specimens withstood the lower exposure with little or no reduction in cell population. Upon exposing the microbes to the larger dose of 6 x 10 4 rad, we observed two distinct groupings: microbes that demonstrate resistance to radiation, and microbes that display intolerance through a dramatic reduction from their initial population. Microbes in the radiation tolerant grouping were exposed to 1.1 x 10 5 rad to examine the extent of their resistance. We observe a correlation between radiation resistance and gram stain. The gram-positive species we examined seem to demonstrate a greater radiation resistance

  3. Irradiation of Microbes from Spent Nuclear Fuel Storage Pool Environments

    Energy Technology Data Exchange (ETDEWEB)

    Breckenridge, C.R.; Watkins, C.S.; Bruhn, D.F.; Roberto, F.F.; Tsang, M.N.; Pinhero, P.J. [INEEL (US); Brey, R.F. [ISU (US); Wright, R.N.; Windes, W.F.

    1999-09-03

    Microbes have been isolated and identified from spent nuclear fuel storage pools at the Idaho National Engineering and Environmental Laboratory (INEEL). Included among these are Corynebacterium aquaticum, Pseudomonas putida, Comamonas acidovorans, Gluconobacter cerinus, Micrococcus diversus, Rhodococcus rhodochrous, and two strains of sulfate-reducing bacteria (SRB). We examined the sensitivity of these microbes to a variety of total exposures of radiation generated by a 6-MeV linear accelerator (LINAC). The advantage of using a LINAC is that it provides a relatively quick screen of radiation tolerance. In the first set of experiments, we exposed each of the aforementioned microbes along with four additional microbes, pseudomonas aeruginosa, Micrococcus luteus, Escherchia coli, and Deinococcus radiodurans to exposures of 5 x 10{sup 3} and 6 x 10{sup 4} rad. All microbial specimens withstood the lower exposure with little or no reduction in cell population. Upon exposing the microbes to the larger dose of 6 x 10{sup 4} rad, we observed two distinct groupings: microbes that demonstrate resistance to radiation, and microbes that display intolerance through a dramatic reduction from their initial population. Microbes in the radiation tolerant grouping were exposed to 1.1 x 10{sup 5} rad to examine the extent of their resistance. We observe a correlation between radiation resistance and gram stain. The gram-positive species we examined seem to demonstrate a greater radiation resistance.

  4. Construction and characterization of novel stress-responsive Deinococcal biosensors

    International Nuclear Information System (INIS)

    Joe, Min Ho; Lim, Sang Youg

    2012-01-01

    In this research, we constructed a recombinant whole-cell biosensor to detect mutagens (H2O2, mitomycin C, MNNG, bleomycin) using Deinococcus radiodurans and evaluated its possibility for actual application. We performed DNA microarray analysis and selected 10 candidate genes for biosensor recombinant plasmid construction. The expression of ddrA, ddrB, DR 0 161, DR 0 589, and pprA was highly increased after treatment of the target mutagens. Putative promoter region of the genes were used for LacZ-based biosensor plasmid construction by replacing groESL promoter of pRADZ3. Pormoter activity and specificity of the five recombinant LacZ-based biosensor strains harboring the recombinant plasmids was measured. The result indicated that the promoter region of ddrA is the most suitable promoter for the biosensor development. Red pigment-based biosensor plasmid was constructed by displacing lacZ with crtI. The sensor strain was constructed by transforming the sensor plasmid into crtI deleted mutant D. radiodurans strain. Finally, macroscopic detection of the target mutagens by the biosensor strain was evaluated. The strength of red pigment biosynthesis by this recombinant strain in response to the target mutagens was weaker than our expectation. Continuous damage to the sensor strain by the mutagens in the medium might be the main reason for this low red-pigment biosynthesis. Therefore, we propose that the LacZ-based biosensor is more effective than the biosensor using red pigment as indicator for the mutagen detection

  5. The Deinococcus-Thermus phylum and the effect of rRNA composition on phylogenetic tree construction

    Science.gov (United States)

    Weisburg, W. G.; Giovannoni, S. J.; Woese, C. R.

    1989-01-01

    Through comparative analysis of 16S ribosomal RNA sequences, it can be shown that two seemingly dissimilar types of eubacteria Deinococcus and the ubiquitous hot spring organism Thermus are distantly but specifically related to one another. This confirms an earlier report based upon 16S rRNA oligonucleotide cataloging studies (Hensel et al., 1986). Their two lineages form a distinctive grouping within the eubacteria that deserved the taxonomic status of a phylum. The (partial) sequence of T. aquaticus rRNA appears relatively close to those of other thermophilic eubacteria. e.g. Thermotoga maritima and Thermomicrobium roseum. However, this closeness does not reflect a true evolutionary closeness; rather it is due to a "thermophilic convergence", the result of unusually high G+C composition in the rRNAs of thermophilic bacteria. Unless such compositional biases are taken into account, the branching order and root of phylogenetic trees can be incorrectly inferred.

  6. Normalization Approaches for Removing Systematic Biases Associated with Mass Spectrometry and Label-Free Proteomics

    Energy Technology Data Exchange (ETDEWEB)

    Callister, Stephen J.; Barry, Richard C.; Adkins, Joshua N.; Johnson, Ethan T.; Qian, Weijun; Webb-Robertson, Bobbie-Jo M.; Smith, Richard D.; Lipton, Mary S.

    2006-02-01

    Central tendency, linear regression, locally weighted regression, and quantile techniques were investigated for normalization of peptide abundance measurements obtained from high-throughput liquid chromatography-Fourier transform ion cyclotron resonance mass spectrometry (LC-FTICR MS). Arbitrary abundances of peptides were obtained from three sample sets, including a standard protein sample, two Deinococcus radiodurans samples taken from different growth phases, and two mouse striatum samples from control and methamphetamine-stressed mice (strain C57BL/6). The selected normalization techniques were evaluated in both the absence and presence of biological variability by estimating extraneous variability prior to and following normalization. Prior to normalization, replicate runs from each sample set were observed to be statistically different, while following normalization replicate runs were no longer statistically different. Although all techniques reduced systematic bias, assigned ranks among the techniques revealed significant trends. For most LC-FTICR MS analyses, linear regression normalization ranked either first or second among the four techniques, suggesting that this technique was more generally suitable for reducing systematic biases.

  7. Adaptability and variability of the cell functions to the environmental factors

    Energy Technology Data Exchange (ETDEWEB)

    Kikuchi, Tadatoshi [Kyoto Univ., Kumatori, Osaka (Japan). Research Reactor Inst.

    1995-02-01

    Adaptive phenomenon of the cells to the environmental factors is one of the most important functions of cells. In the initial research program, yeast, Saccharomyces cerevisiae, as model species of eukaryote was selected to use for the experiments and copper sulfate was adopted as one of the ideal environmental factors, and then adaptation mechanisms of yeast cells in the environment surrounded by copper ions were analyzed metabolically and morphologically. Furthermore, in the relationships between environmental factors and the cells, the researches performed were as follows: (1) Induced mutation in the extranuclear-inheritable system: Mutagenic effect of ethidium bromide on mitochondria and plastids. (2) Induction of gene expression by light exposure in the early development of chloroplast in Chlamydomonas reinhardi. (3) Some features of RNA and protein syntheses in thermophilic alga Cyanidium caldarium. (4) Satellite DNA of Ochromonas danica. (5) Analyses of cell functions using various kinds of radiations. (6) Novel methionine requirement of radiation resistant bacterium, Deinococcus radiodurans. (author).

  8. Construction and characterization of novel stress-responsive Deinococcal biosensors

    Energy Technology Data Exchange (ETDEWEB)

    Joe, Min Ho; Lim, Sang Youg

    2012-01-15

    In this research, we constructed a recombinant whole-cell biosensor to detect mutagens (H2O2, mitomycin C, MNNG, bleomycin) using Deinococcus radiodurans and evaluated its possibility for actual application. We performed DNA microarray analysis and selected 10 candidate genes for biosensor recombinant plasmid construction. The expression of ddrA, ddrB, DR{sub 0}161, DR{sub 0}589, and pprA was highly increased after treatment of the target mutagens. Putative promoter region of the genes were used for LacZ-based biosensor plasmid construction by replacing groESL promoter of pRADZ3. Pormoter activity and specificity of the five recombinant LacZ-based biosensor strains harboring the recombinant plasmids was measured. The result indicated that the promoter region of ddrA is the most suitable promoter for the biosensor development. Red pigment-based biosensor plasmid was constructed by displacing lacZ with crtI. The sensor strain was constructed by transforming the sensor plasmid into crtI deleted mutant D. radiodurans strain. Finally, macroscopic detection of the target mutagens by the biosensor strain was evaluated. The strength of red pigment biosynthesis by this recombinant strain in response to the target mutagens was weaker than our expectation. Continuous damage to the sensor strain by the mutagens in the medium might be the main reason for this low red-pigment biosynthesis. Therefore, we propose that the LacZ-based biosensor is more effective than the biosensor using red pigment as indicator for the mutagen detection.

  9. Biofilms and planktonic cells of Deinococcus geothermalis in extreme environments

    Science.gov (United States)

    Panitz, Corinna; Reitz, Guenther; Rabbow, Elke; Rettberg, Petra; Flemming, Hans-Curt; Wingender, Jost; Froesler, Jan

    In addition to the several extreme environments on Earth, Space can be considered as just another exceptional environment with a unique mixture of stress factors comprising UV radiation, vacuum, desiccation, temperature, ionizing radiation and microgravity. Life that processes in these environments can depend on the life forms and their state of living. The question is whether there are different strategies for individual microorganisms compared to communities of the same organisms to cope with the different factors of their surroundings. Comparative studies of the survi-val of these communities called biofilms and planktonic cell samples of Deinococcus geothermalis stand at the focal point of the presented investigations. A biofilm is a structured community of microorganisms that live encapsulated in a matrix of extracellular polymeric substances on a surface. Microorganisms living in a biofilm usually have significantly different properties to cooperate than individually living microorganisms of the same species. An advantage of the biofilm is increased resistance to various chemical and physical effects, while the dense extracellular matrix and the outer layer of the cells protect the interior of the microbial consortium. The space experiment BOSS (Biofilm organisms surfing Space) as part the ESA experimental unit EXPOSE R-2 with a planned launch date in July 2014 will be subsequently mounted on the Russian Svesda module outside the ISS. An international team of scientists coordinated by Dr. P. Rettberg will investigate the hypothesis whether microorganisms organized as biofilm outmatch the same microorganisms exposed individually in the long-term survival of the harsh environmental conditions as they occur in space and on Mars. Another protective function in the samples could be dust par-ticles for instance Mars regolith simulant contained inside the biofilms or mixed with the planktonic cells, as additional shelter especially against the extraterrestrial UV

  10. Synthesis of Hyperbranched Glycoconjugates by the Combined Action of Potato Phosphorylase and Glycogen Branching Enzyme from Deinococcus geothermalis

    Directory of Open Access Journals (Sweden)

    Katja Loos

    2012-02-01

    Full Text Available Potato phosphorylase is able to synthesize linear polyglucans from maltoheptaose primers. By coupling maltoheptaose to butane diamine, tris(2-aminoethylamine and amine functionalized amine functionalized poly ethyleneglycol (PEG, new primer molecules became available. The resulting di-, tri- and macro-primers were incubated with potato phosphorylase and glycogen branching enzyme from Deinococcus geothermalis. Due to the action of both enzymes, hyperbranched polyglucan arms were grown from the maltoheptaose derivatives with a maximum degree of branching of 11%. The size of the synthesized hyperbranched polyglucans could be controlled by the ratio monomer over primer. About 60%–80% of the monomers were incorporated in the glycoconjugates. The resulting hyperbranched glycoconjugates were subjected to Dynamic Light Scattering (DLS measurements in order to determine the hydrodynamic radius and it became obvious that the structures formed agglomerates in the range of 14–32 nm.

  11. Silicates Eroded under Simulated Martian Conditions Effectively Kill Bacteria-A Challenge for Life on Mars.

    Science.gov (United States)

    Bak, Ebbe N; Larsen, Michael G; Moeller, Ralf; Nissen, Silas B; Jensen, Lasse R; Nørnberg, Per; Jensen, Svend J K; Finster, Kai

    2017-01-01

    The habitability of Mars is determined by the physical and chemical environment. The effect of low water availability, temperature, low atmospheric pressure and strong UV radiation has been extensively studied in relation to the survival of microorganisms. In addition to these stress factors, it was recently found that silicates exposed to simulated saltation in a Mars-like atmosphere can lead to a production of reactive oxygen species. Here, we have investigated the stress effect induced by quartz and basalt abraded in Mars-like atmospheres by examining the survivability of the three microbial model organisms Pseudomonas putida, Bacillus subtilis , and Deinococcus radiodurans upon exposure to the abraded silicates. We found that abraded basalt that had not been in contact with oxygen after abrasion killed more than 99% of the vegetative cells while endospores were largely unaffected. Exposure of the basalt samples to oxygen after abrasion led to a significant reduction in the stress effect. Abraded quartz was generally less toxic than abraded basalt. We suggest that the stress effect of abraded silicates may be caused by a production of reactive oxygen species and enhanced by transition metal ions in the basalt leading to hydroxyl radicals through Fenton-like reactions. The low survivability of the usually highly resistant D. radiodurans indicates that the effect of abraded silicates, as is ubiquitous on the Martian surface, would limit the habitability of Mars as well as the risk of forward contamination. Furthermore, the reactivity of abraded silicates could have implications for future manned missions, although the lower effect of abraded silicates exposed to oxygen suggests that the effects would be reduced in human habitats.

  12. Silicates Eroded under Simulated Martian Conditions Effectively Kill Bacteria—A Challenge for Life on Mars

    Directory of Open Access Journals (Sweden)

    Ebbe N. Bak

    2017-09-01

    Full Text Available The habitability of Mars is determined by the physical and chemical environment. The effect of low water availability, temperature, low atmospheric pressure and strong UV radiation has been extensively studied in relation to the survival of microorganisms. In addition to these stress factors, it was recently found that silicates exposed to simulated saltation in a Mars-like atmosphere can lead to a production of reactive oxygen species. Here, we have investigated the stress effect induced by quartz and basalt abraded in Mars-like atmospheres by examining the survivability of the three microbial model organisms Pseudomonas putida, Bacillus subtilis, and Deinococcus radiodurans upon exposure to the abraded silicates. We found that abraded basalt that had not been in contact with oxygen after abrasion killed more than 99% of the vegetative cells while endospores were largely unaffected. Exposure of the basalt samples to oxygen after abrasion led to a significant reduction in the stress effect. Abraded quartz was generally less toxic than abraded basalt. We suggest that the stress effect of abraded silicates may be caused by a production of reactive oxygen species and enhanced by transition metal ions in the basalt leading to hydroxyl radicals through Fenton-like reactions. The low survivability of the usually highly resistant D. radiodurans indicates that the effect of abraded silicates, as is ubiquitous on the Martian surface, would limit the habitability of Mars as well as the risk of forward contamination. Furthermore, the reactivity of abraded silicates could have implications for future manned missions, although the lower effect of abraded silicates exposed to oxygen suggests that the effects would be reduced in human habitats.

  13. Spectroscopic investigation of ionizing-radiation tolerance of a Chlorophyceae green micro-alga

    Energy Technology Data Exchange (ETDEWEB)

    Farhi, E; Compagnon, E; Marzloff, V; Ollivier, J; Boisson, A M; Natali, F; Russo, D [Institut Laue-Langevin, BP 156, 38042 Grenoble cedex 9 (France); Rivasseau, C; Gromova, M; Bligny, R [CEA, Laboratoire de Physiologie Cellulaire Vegetale, 17 rue des Martyrs, 38054 Grenoble cedex 9 (France); Coute, A [Museum National d' Histoire Naturelle, Laboratoire de Cryptogamie, 2 rue Buffon, 75005 Paris (France)

    2008-03-12

    Micro-organisms living in extreme environments are captivating in the peculiar survival processes they have developed. Deinococcus radiodurans is probably the most famous radio-resistant bacteria. Similarly, a specific ecosystem has grown in a research reactor storage pool, and has selected organisms which may sustain radiative stress. An original green micro-alga which was never studied for its high tolerance to radiations has been isolated. It is the only autotrophic eukaryote that develops in this pool, although contamination possibilities coming from outside are not unusual. Studying what could explain this irradiation tolerance is consequently very interesting. An integrative study of the effects of irradiation on the micro-algae physiology, metabolism, internal dynamics, and genomics was initiated. In the work presented here, micro-algae were stressed with irradiation doses up to 20 kGy (2 Mrad), and studied by means of nuclear magnetic resonance, looking for modifications in the metabolism, and on the IN13 neutron backscattering instrument at the ILL, looking for both dynamics and structural macromolecular changes in the cells.

  14. Manganese(II) induces cell division and increases in superoxide dismutase and catalase activities in an aging deinococcal culture

    International Nuclear Information System (INIS)

    Chou, F.I.; Tan, S.T.

    1990-01-01

    Addition of Mn(II) at 2.5 microM or higher to stationary-phase cultures of Deinococcus radiodurans IR was found to trigger at least three rounds of cell division. This Mn(II)-induced cell division (Mn-CD) did not occur when the culture was in the exponential or death phase. The Mn-CD effect produced daughter cells proportionally reduced in size, pigmentation, and radioresistance but proportionally increased in activity and amount of the oxygen toxicity defense enzymes superoxide dismutase and catalase. In addition, the concentration of an Mn-CD-induced protein was found to remain high throughout the entire Mn-CD phase. It was also found that an untreated culture exhibited a growth curve characterized by a very rapid exponential-stationary transition and that cells which had just reached the early stationary phase were synchronous. Our results suggest the presence of an Mn(II)-sensitive mechanism for controlling cell division. The Mn-CD effect appears to be specific to the cation Mn(II) and the radioresistant bacteria, deinococci

  15. Spectroscopic investigation of ionizing-radiation tolerance of a Chlorophyceae green micro-alga

    International Nuclear Information System (INIS)

    Farhi, E; Compagnon, E; Marzloff, V; Ollivier, J; Boisson, A M; Natali, F; Russo, D; Rivasseau, C; Gromova, M; Bligny, R; Coute, A

    2008-01-01

    Micro-organisms living in extreme environments are captivating in the peculiar survival processes they have developed. Deinococcus radiodurans is probably the most famous radio-resistant bacteria. Similarly, a specific ecosystem has grown in a research reactor storage pool, and has selected organisms which may sustain radiative stress. An original green micro-alga which was never studied for its high tolerance to radiations has been isolated. It is the only autotrophic eukaryote that develops in this pool, although contamination possibilities coming from outside are not unusual. Studying what could explain this irradiation tolerance is consequently very interesting. An integrative study of the effects of irradiation on the micro-algae physiology, metabolism, internal dynamics, and genomics was initiated. In the work presented here, micro-algae were stressed with irradiation doses up to 20 kGy (2 Mrad), and studied by means of nuclear magnetic resonance, looking for modifications in the metabolism, and on the IN13 neutron backscattering instrument at the ILL, looking for both dynamics and structural macromolecular changes in the cells

  16. Prospects for Fungal Bioremediation of Acidic Radioactive Waste Sites: Characterization and Genome Sequence of Rhodotorula taiwanensis MD1149.

    Science.gov (United States)

    Tkavc, Rok; Matrosova, Vera Y; Grichenko, Olga E; Gostinčar, Cene; Volpe, Robert P; Klimenkova, Polina; Gaidamakova, Elena K; Zhou, Carol E; Stewart, Benjamin J; Lyman, Mathew G; Malfatti, Stephanie A; Rubinfeld, Bonnee; Courtot, Melanie; Singh, Jatinder; Dalgard, Clifton L; Hamilton, Theron; Frey, Kenneth G; Gunde-Cimerman, Nina; Dugan, Lawrence; Daly, Michael J

    2017-01-01

    Highly concentrated radionuclide waste produced during the Cold War era is stored at US Department of Energy (DOE) production sites. This radioactive waste was often highly acidic and mixed with heavy metals, and has been leaking into the environment since the 1950s. Because of the danger and expense of cleanup of such radioactive sites by physicochemical processes, in situ bioremediation methods are being developed for cleanup of contaminated ground and groundwater. To date, the most developed microbial treatment proposed for high-level radioactive sites employs the radiation-resistant bacterium Deinococcus radiodurans . However, the use of Deinococcus spp. and other bacteria is limited by their sensitivity to low pH. We report the characterization of 27 diverse environmental yeasts for their resistance to ionizing radiation (chronic and acute), heavy metals, pH minima, temperature maxima and optima, and their ability to form biofilms. Remarkably, many yeasts are extremely resistant to ionizing radiation and heavy metals. They also excrete carboxylic acids and are exceptionally tolerant to low pH. A special focus is placed on Rhodotorula taiwanensis MD1149, which was the most resistant to acid and gamma radiation. MD1149 is capable of growing under 66 Gy/h at pH 2.3 and in the presence of high concentrations of mercury and chromium compounds, and forming biofilms under high-level chronic radiation and low pH. We present the whole genome sequence and annotation of R. taiwanensis strain MD1149, with a comparison to other Rhodotorula species. This survey elevates yeasts to the frontier of biology's most radiation-resistant representatives, presenting a strong rationale for a role of fungi in bioremediation of acidic radioactive waste sites.

  17. Description of Deinococcus oregonensis sp. nov., from biological soil crusts in the Southwestern arid lands of the United States of America.

    Science.gov (United States)

    Gundlapally, Sathyanarayana Reddy; Garcia-Pichel, Ferran

    2017-01-01

    Biological soil crusts are distinct habitats, harbor unique prokaryotic diversity and gave an impetus to isolate novel species. In the present study, a pink-pigmented bacterium, (OR316-6 T ), was isolated from biological soil crusts using oligotrophic BG11-PGY medium. Strain OR316-6 T was Gram-positive, short rods, non-motile and non-spore forming. Cells were positive for catalase, oxidase and β-galactosidase and negative for most of the enzymatic activities. The major fatty acids present were C 16:0 , C 17:0 , and C 16:1 ω7c and contained MK-8 and MK-10 as the predominant menaquinones. The cell wall peptidoglycan was of A3β variant with L-ornithine as the diamino acid. Based on the above characteristics, strain OR316-6 T was assigned to the genus Deinococcus. The phylogenetic analysis indicated that strain OR316-6 T was closely related to D. aquatilis DSM 23025 T with a 16S rRNA gene similarity of 99.3 % and clustered with a bootstrap value of 100 %. DNA-DNA similarity between strain OR316-6 T and D. aquatilis DSM 23025 T was 37.0 % indicating that strain OR316-6 T was a novel species. Further, DNA fingerprinting of stains OR316-6 T and D. aquatilis DSM 23035 T demonstrated that both strains were related to each other with a similarity coefficient of only 0.32 and supported the species status to strain OR316-6 T . In addition, phenotypic characteristics distinguished strain OR316-6 T from D. aquatilis DSM 23025 T . Based on the cumulative differences, strain OR316-16 T exhibited with its closely related species, it was identified as a novel species and proposed the name Deinococcus oregonensis sp. nov. The type strain is D. oregonensis sp. nov. (OR316-6 T  = JCM 13503 T  = DSM 17762 T ).

  18. Bacterial Diversity in Bentonites, Engineered Barrier for Deep Geological Disposal of Radioactive Wastes.

    Science.gov (United States)

    Lopez-Fernandez, Margarita; Cherkouk, Andrea; Vilchez-Vargas, Ramiro; Jauregui, Ruy; Pieper, Dietmar; Boon, Nico; Sanchez-Castro, Ivan; Merroun, Mohamed L

    2015-11-01

    The long-term disposal of radioactive wastes in a deep geological repository is the accepted international solution for the treatment and management of these special residues. The microbial community of the selected host rocks and engineered barriers for the deep geological repository may affect the performance and the safety of the radioactive waste disposal. In this work, the bacterial population of bentonite formations of Almeria (Spain), selected as a reference material for bentonite-engineered barriers in the disposal of radioactive wastes, was studied. 16S ribosomal RNA (rRNA) gene-based approaches were used to study the bacterial community of the bentonite samples by traditional clone libraries and Illumina sequencing. Using both techniques, the bacterial diversity analysis revealed similar results, with phylotypes belonging to 14 different bacterial phyla: Acidobacteria, Actinobacteria, Armatimonadetes, Bacteroidetes, Chloroflexi, Cyanobacteria, Deinococcus-Thermus, Firmicutes, Gemmatimonadetes, Planctomycetes, Proteobacteria, Nitrospirae, Verrucomicrobia and an unknown phylum. The dominant groups of the community were represented by Proteobacteria and Bacteroidetes. A high diversity was found in three of the studied samples. However, two samples were less diverse and dominated by Betaproteobacteria.

  19. Loss of covalently linked lipid as the mechanism for radiation-induced release of membrane-bound polysaccharide and exonuclease from Micrococcus radiodurans

    International Nuclear Information System (INIS)

    Mitchel, R.E.J.

    1981-01-01

    The mechanism of γ-radiation-induced release of polysaccharide and exonuclease from the midwall membrane of Micrococcus radiodurans has been examined. These two components appear to be released independently, but by very similar processes. Direct analysis of radiation-released polysaccharide indicated the absence of an alkali-labile neutral lipid normally present in the native material. Radiation-induced release therefore probably results from the radiolytic cleavage of a covalently linked lipid which normally serves to anchor these substances to the membrane. The absence of a natural membrane-bound carotenoid had no effect on the rate of release of these components. Likewise, the absence of exonuclease in an exonuclease minus mutant did not influence the release of polysaccharide. It is suggested that the major pathway of radical transfer from the initiating .OH and culminating in the cleavage of the neutral lipid anchor may not be via the membrane

  20. [Unique properties of highly radioresistant bacteria].

    Science.gov (United States)

    Romanovskaia, V A; Rokitko, P V; Malashenko, Iu R

    2000-01-01

    In connection with the Chernobyl Nuclear Power Plant (ChNPP) accident and the negative ecological after-effects for biota in this zone the interest has arisen to radioresistant bacteria, as to the most dynamic model of the given ecosystem, and to mechanisms which provide resistance of bacteria to ionizing radiation. The analysis of published data has shown that the radioresistant bacteria are not interrelated taxonomically and phylogenetically. The extreme radioresistant bacteria are represented by the Deinococcus species, which form a group phylogenetically close to the line Thermus-Meiothermus. Other radioresistant bacteria are the representatives of the genera Rubrobacter, Methylobacterium, Kocuria, Bacillus and some archebacteria. Data on natural habitats, of radioresistant bacteria are not numerous. In a number of cases it is difficult to distinguish their natural habitats, as they were isolated from the samples which were previously exposed to X-ray or gamma-irradiation, or from the ecosystems with the naturally raised radioactivity. To understand the strategy of survival of radioresistant bacteria, we briefly reviewed the mechanism of action of various species of radiation on cells and macromolecules; physiological signs of the cell damage caused by radiation; mechanisms eliminating (repairing) these damages. More details on mechanisms of the DNA repair in D. radiodurans are described. The extreme resistance of D. radiodurans to the DNA damaging factors is defined by 1) repair mechanisms which fundamentally differ from those in other procaryotes; 2) ability to increase the efficiency of a standard set of the DNA repairing proteins. Literary and own data on the effect of radiation on survival of various groups of bacteria in natural ecosystems are summarized. The ecological consequences of the ChNPP accident for soil bacteria in this region were estimated. The reduction of the number of soil bacteria and recession of microbial diversity under the effect of

  1. Prospects for Fungal Bioremediation of Acidic Radioactive Waste Sites: Characterization and Genome Sequence of Rhodotorula taiwanensis MD1149

    Directory of Open Access Journals (Sweden)

    Rok Tkavc

    2018-01-01

    Full Text Available Highly concentrated radionuclide waste produced during the Cold War era is stored at US Department of Energy (DOE production sites. This radioactive waste was often highly acidic and mixed with heavy metals, and has been leaking into the environment since the 1950s. Because of the danger and expense of cleanup of such radioactive sites by physicochemical processes, in situ bioremediation methods are being developed for cleanup of contaminated ground and groundwater. To date, the most developed microbial treatment proposed for high-level radioactive sites employs the radiation-resistant bacterium Deinococcus radiodurans. However, the use of Deinococcus spp. and other bacteria is limited by their sensitivity to low pH. We report the characterization of 27 diverse environmental yeasts for their resistance to ionizing radiation (chronic and acute, heavy metals, pH minima, temperature maxima and optima, and their ability to form biofilms. Remarkably, many yeasts are extremely resistant to ionizing radiation and heavy metals. They also excrete carboxylic acids and are exceptionally tolerant to low pH. A special focus is placed on Rhodotorula taiwanensis MD1149, which was the most resistant to acid and gamma radiation. MD1149 is capable of growing under 66 Gy/h at pH 2.3 and in the presence of high concentrations of mercury and chromium compounds, and forming biofilms under high-level chronic radiation and low pH. We present the whole genome sequence and annotation of R. taiwanensis strain MD1149, with a comparison to other Rhodotorula species. This survey elevates yeasts to the frontier of biology's most radiation-resistant representatives, presenting a strong rationale for a role of fungi in bioremediation of acidic radioactive waste sites.

  2. DNA repair mechanism in radioresistant bacteria

    International Nuclear Information System (INIS)

    Kitayama, Shigeru

    1992-01-01

    Many radiation resistant bacteria have been isolated from various sources which are not in high background field. Since Deinococcus radiodurans had been isolated first in 1956, studies on the mechanism for radioresistance were carried out mostly using this bacterium. DNA in this bacterium isn't protected against injury induced by not only ionizing radiation but also ultraviolet light. Therefore, DNA damages induced by various treatments are efficiently and accurately repaired in this cells. Damages in base and/or sugar in DNA are removed by endonucleases which, if not all, are synthesized during postirradiation incubation. Following the endonucleolytic cleavage the strand scissions in DNA are seemed to be rejoined by a process common for the repair of strand scissions induced by such as ionizing radiations. Induce protein(s) is also involved in this rejoining process of strand scissions. DNA repair genes were classified into three phenotypic groups. (1)Genes which are responsible for the endonucleolytic activities. (2) Genes involved in the rejoining of DNA strand scissions. (3) Genes which participate in genetic recombination and repair. Three genes belong to (1) and (2) were cloned onto approximately 1 kbp DNA fragments which base sequences have been determined. (author)

  3. DNA repair mechanism in radioresistant bacteria

    International Nuclear Information System (INIS)

    Kitayama, Shigeru

    1992-01-01

    Many radiation resistant bacteria have been isolated from various sources which are not in high background field. Since Deinococcus radiodurans had been isolated first in 1956, the studies on the mechanism of radioresistance were mostly carried out using this bacterium. DNA in this bacterium isn't protected against injury induced by not only ionizing radiation but also ultraviolet light. Therefore, DNA damages induced by various treatments are efficiently and accurately repaired in this cells. Damages in base and/or sugar in DNA are removed by endonucleases which, if not all, are synthesized during postirradiation incubation. Following the endonucleolytic cleavage the strand scissions in DNA are seemed to be rejoined by a process common for the repair of strand scissions induced by such as ionizing radiations. Induce protein(s) is also involved in this rejoining process of strand scissions. DNA repair genes were classified into three phenotypic groups. (1) Genes which are responsible for the endonucleolytic activities. (2) Genes involved in the rejoining of DNA strand scissions. (3) Genes which participate in genetic recombination and repair. Three genes belong to (1) and (2) were cloned onto approximately 1 kbp DNA fragments which base sequences have been determined. (author)

  4. A probabilistic framework for microarray data analysis: fundamental probability models and statistical inference.

    Science.gov (United States)

    Ogunnaike, Babatunde A; Gelmi, Claudio A; Edwards, Jeremy S

    2010-05-21

    Gene expression studies generate large quantities of data with the defining characteristic that the number of genes (whose expression profiles are to be determined) exceed the number of available replicates by several orders of magnitude. Standard spot-by-spot analysis still seeks to extract useful information for each gene on the basis of the number of available replicates, and thus plays to the weakness of microarrays. On the other hand, because of the data volume, treating the entire data set as an ensemble, and developing theoretical distributions for these ensembles provides a framework that plays instead to the strength of microarrays. We present theoretical results that under reasonable assumptions, the distribution of microarray intensities follows the Gamma model, with the biological interpretations of the model parameters emerging naturally. We subsequently establish that for each microarray data set, the fractional intensities can be represented as a mixture of Beta densities, and develop a procedure for using these results to draw statistical inference regarding differential gene expression. We illustrate the results with experimental data from gene expression studies on Deinococcus radiodurans following DNA damage using cDNA microarrays. Copyright (c) 2010 Elsevier Ltd. All rights reserved.

  5. Effect of pulsed electron beam on cell killing

    International Nuclear Information System (INIS)

    Acharya, Santhosh; Joseph, Praveen; Sanjeev, Ganesh; Narayana, Y.; Bhat, N.N.

    2009-01-01

    The extent of repairable and irreparable damage in a living cell produced by ionizing radiation depends on the quality of the radiation. In the case of sparsely ionizing radiation, the dose rate and the pattern of energy deposition of the radiation are the important physical factors which can affect the amount of damage in living cells. In the present study, radio-sensitive and radioresistive bacteria cells were exposed to 8 MeV pulsed electron beam and the efficiency of cell-killing was investigated to evaluate the Do, the mean lethal dose. The dose to the cell was delivered in micro-second pulses at an instantaneous dose rate of 2.6 x 10 5 Gy s -1 . Fricke dosimeter was used to measure the absorbed dose of electron beam. The results were compared with those of gamma rays. The survival curve of radio-resistive Deinococcus-radiodurans (DR) is found to be sigmoidal and the survival response for radio-sensitive Escherichia-coli (E-coli) is found to be exponential without any shoulder. Comparison of Do values indicate that irradiation with pulsed electron beam resulted in more cell-killing than was observed for gamma irradiation. (author)

  6. Expression and purification of PprI protein from D.radiodurans R1 in escherichia coli

    International Nuclear Information System (INIS)

    Zhang Yongqin; Zhou Hui; Chen Jie; Yang Zhanshan

    2011-01-01

    In order to express and purify PprI protein from D.radiodurans R1 in E. coli, the full length of pprI gene was gained by PCR amplification using pCMV-HA-pprI as a template. The gene segment was inserted into vector pET-28a after digested by two restriction endonucleases Nco I and EcoR I. Then the recombinant vector pET-28a-His-pprI was transfected into E. coli BL21(DE3) RP. The PprI protein expression was induced by IPTG and the fusion protein was confirmed by SDS-PAGE and Western blotting. The expressive conditions of the protein such as E. coli' A 600 , concentration of IPTG, time and temperature of culture, were optimized. Finally the fusion protein was purified by Ni-NTA His Bind Resins and molecule boult. The experimental results show the fusion protein confirmed by Western blotting is 6 x His-PprI and its molecular weight is 37 kDa. The ladders of PprI protein at molecular weight 37 kDa were different due to difference of the PprI protein expression conditions if E. coli. The PprI protein exists both in supernatant and precipitation. The concentration of purified protein is about 0.15 mg/mL which was measured by BCA method. It is concluded that the recombinant plasmid pET-28a-His-pprI is constructed and the PprI fusion protein is expressed and purified. The results lay a solid foundation for studying the radio-resistance and immunity of PprI protein. (authors)

  7. Micrococcus radiodurans surface exonuclease. Dimer to monomer conversion by ionizing radiation-generated aqueous free radicals

    Energy Technology Data Exchange (ETDEWEB)

    Mitchel, R E.J.

    1980-01-01

    Micrococcus radiodurans possesses an exonuclease firmly bound to a middle cell wall membrane layer. Aqueous OH/sup -/ radicals generated chemically or by ionizing radiation cause the immediate release of this enzyme into the surrounding medium. The enzyme is located in a hydrophobic site and can also be released by aqueous n-butanol. When extracted by this solvent it is a non-covalently linked dimer and has a molecular weight of 260,000 as determined by gel filtration. When released by radiation generated OH/sup -/ radicals, the enzyme initially appears in solution as the dimer but is rapidly split by further aqueous radical attack into two 130,000 molecular weight subunits. Hydroxyl radicals are most effective but reducing radicals are also able to monomerize the enzyme. Only the released dimer enzyme is subject to free radical monomerization. Bound dimer enzyme is not split prior to release. No detectable loss of activity or change in catalytic properties accompanies the free radical cleavage of the enzyme. Both subunits of the dimer enzyme possess a tightly bound metal ion (probably Ca/sup 2 +/) required for activity. The monomer but not the dimer enzyme will bind to an anion exchanger. The monomer is susceptible to loss of its metal ion, and consequent inactivation, when exposed to the exchanger in the absence of Ca/sup 2 +/. Besides providing information on some of the immediate non-lethal effects of ionizing radiation, the behavior of this enzyme system demonstrates a potential cellular mechanism by which internally or externally generated free radicals could be utilized by the cell to control various enzymic reactions.

  8. Survival of thermophilic and hyper-thermophilic microorganisms after exposure to UV-C, ionizing radiation and desiccation

    International Nuclear Information System (INIS)

    Beblo, K.; Wirth, R.; Huber, H.; Douki, T.; Schmalz, G.; Rachel, R.

    2011-01-01

    In this study, we investigated the ability of several (hyper-) thermophilic Archaea and phylo-genetically deep-branching thermophilic Bacteria to survive high fluences of monochromatic UV-C (254 nm) and high doses of ionizing radiation, respectively. Nine out of fourteen tested microorganisms showed a surprisingly high tolerance against ionizing radiation, and two species (Aquifex pyrophilus and Ignicoccus hospitalis) were even able to survive 20 kGy. Therefore, these species had a comparable survivability after exposure to ionizing radiation such as Deinococcus radiodurans. In contrast, there was nearly no difference in survival of the tested strains after exposure to UV-C under anoxic conditions. If the cells had been dried in advance of UV-C irradiation, they were more sensitive to UV-C radiation compared with cells irradiated in liquid suspension; this effect could be reversed by the addition of protective material like sulfidic ores before irradiation. By exposure to UV-C, photoproducts were formed in the DNA of irradiated Archaea and Bacteria. The distribution of the main photoproducts was species specific, but the amount of the photoproducts was only partly dependent on the applied fluence. Overall, our results show that tolerance to radiation seems to be a common phenomenon among thermophilic and hyper-thermophilic microorganisms. (authors)

  9. Survival of thermophilic and hyperthermophilic microorganisms after exposure to UV-C, ionizing radiation and desiccation.

    Science.gov (United States)

    Beblo, Kristina; Douki, Thierry; Schmalz, Gottfried; Rachel, Reinhard; Wirth, Reinhard; Huber, Harald; Reitz, Günther; Rettberg, Petra

    2011-11-01

    In this study, we investigated the ability of several (hyper-) thermophilic Archaea and phylogenetically deep-branching thermophilic Bacteria to survive high fluences of monochromatic UV-C (254 nm) and high doses of ionizing radiation, respectively. Nine out of fourteen tested microorganisms showed a surprisingly high tolerance against ionizing radiation, and two species (Aquifex pyrophilus and Ignicoccus hospitalis) were even able to survive 20 kGy. Therefore, these species had a comparable survivability after exposure to ionizing radiation such as Deinococcus radiodurans. In contrast, there was nearly no difference in survival of the tested strains after exposure to UV-C under anoxic conditions. If the cells had been dried in advance of UV-C irradiation, they were more sensitive to UV-C radiation compared with cells irradiated in liquid suspension; this effect could be reversed by the addition of protective material like sulfidic ores before irradiation. By exposure to UV-C, photoproducts were formed in the DNA of irradiated Archaea and Bacteria. The distribution of the main photoproducts was species specific, but the amount of the photoproducts was only partly dependent on the applied fluence. Overall, our results show that tolerance to radiation seems to be a common phenomenon among thermophilic and hyperthermophilic microorganisms.

  10. The complete genome and proteome of Laribacter hongkongensis reveal potential mechanisms for adaptations to different temperatures and habitats.

    Science.gov (United States)

    Woo, Patrick C Y; Lau, Susanna K P; Tse, Herman; Teng, Jade L L; Curreem, Shirly O T; Tsang, Alan K L; Fan, Rachel Y Y; Wong, Gilman K M; Huang, Yi; Loman, Nicholas J; Snyder, Lori A S; Cai, James J; Huang, Jian-Dong; Mak, William; Pallen, Mark J; Lok, Si; Yuen, Kwok-Yung

    2009-03-01

    Laribacter hongkongensis is a newly discovered Gram-negative bacillus of the Neisseriaceae family associated with freshwater fish-borne gastroenteritis and traveler's diarrhea. The complete genome sequence of L. hongkongensis HLHK9, recovered from an immunocompetent patient with severe gastroenteritis, consists of a 3,169-kb chromosome with G+C content of 62.35%. Genome analysis reveals different mechanisms potentially important for its adaptation to diverse habitats of human and freshwater fish intestines and freshwater environments. The gene contents support its phenotypic properties and suggest that amino acids and fatty acids can be used as carbon sources. The extensive variety of transporters, including multidrug efflux and heavy metal transporters as well as genes involved in chemotaxis, may enable L. hongkongensis to survive in different environmental niches. Genes encoding urease, bile salts efflux pump, adhesin, catalase, superoxide dismutase, and other putative virulence factors-such as hemolysins, RTX toxins, patatin-like proteins, phospholipase A1, and collagenases-are present. Proteomes of L. hongkongensis HLHK9 cultured at 37 degrees C (human body temperature) and 20 degrees C (freshwater habitat temperature) showed differential gene expression, including two homologous copies of argB, argB-20, and argB-37, which encode two isoenzymes of N-acetyl-L-glutamate kinase (NAGK)-NAGK-20 and NAGK-37-in the arginine biosynthesis pathway. NAGK-20 showed higher expression at 20 degrees C, whereas NAGK-37 showed higher expression at 37 degrees C. NAGK-20 also had a lower optimal temperature for enzymatic activities and was inhibited by arginine probably as negative-feedback control. Similar duplicated copies of argB are also observed in bacteria from hot springs such as Thermus thermophilus, Deinococcus geothermalis, Deinococcus radiodurans, and Roseiflexus castenholzii, suggesting that similar mechanisms for temperature adaptation may be employed by other

  11. Comparative studies on the effect of ionizing and nonionizing radiations on the kinetics of DNA synthesis and postirradiation degradation in Micrococcus radiodurans R115

    International Nuclear Information System (INIS)

    Auda, H.; Khalef, Z.

    1982-01-01

    The kinetics of degradation and synthesis of DNA and the nature of radioactive substances released from M. radiodurans R 11 5 labeled with thymidine-methyl- 3 H after UV and gamma irradiations were investigated. The release of labeled material from the DNA began immediately upon incubation and terminated in due time 90 min and 180 min for UV and gamma irradiations, respectively. When acriflavine was added to the medium, post-irradiation degradation process did not terminate even after 9 h in the case of UV exposure. However, it terminated after 6 h in the case of gamma irradiation. In the presence of acriflavine, DNA synthesis resumed after termination of DNA degradation in the case of gamma irradiation and this was not observed in the case of UV irradiation. Degradation products were chromatographed and it was found that they were located in one major radioactive peak. However their locations were different for UV and gamma radiations. For UV irradiation, the peak fell in the thymine region, while for gamma irradiation it fell in the thymidine region. (author)

  12. Comparative studies on the effect of ionizing and nonionizing radiations on the kinetics of DNA synthesis and postirradiation degradation in Micrococcus radiodurans R/sub 11/5

    Energy Technology Data Exchange (ETDEWEB)

    Auda, H; Khalef, Z [Nuclear Centre Tuwaitha, Baghdad (Iraq)

    1982-06-01

    The kinetics of degradation and synthesis of DNA and the nature of radioactive substances released from M. radiodurans R/sub 11/5 labeled with thymidine-methyl-/sup 3/H after UV and gamma irradiations were investigated. The release of labeled material from the DNA began immediately upon incubation and terminated in due time 90 min and 180 min for UV and gamma irradiations, respectively. When acriflavine was added to the medium, post-irradiation degradation process did not terminate even after 9 h in the case of UV exposure. However, it terminated after 6 h in the case of gamma irradiation. In the presence of acriflavine, DNA synthesis resumed after termination of DNA degradation in the case of gamma irradiation and this was not observed in the case of UV irradiation. Degradation products were chromatographed and it was found that they were located in one major radioactive peak. However their locations were different for UV and gamma radiations. For UV irradiation, the peak fell in the thymine region, while for gamma irradiation it fell in the thymidine region.

  13. Biology Branch

    Energy Technology Data Exchange (ETDEWEB)

    Baldwin, W F

    1974-12-31

    Progress is reported on the following studies in biochemistry and molecular biology: study of long pyrimidine polynucleotides in DNA; isolation of thymine dimers from Schizosaccharomyces pombe; thermal stability of high molecular weight RNA; nucleases of Micrococcus radiodurans; effect of ionizing radiation on M. radiodurans cell walls and cell membranes; chemical modification of nucleotides; exonucleases of M. radiodurans; and enzymatic basis of repair of radioinduced damage in M. radiodurans. Genetics, development, and population studies include repair pathways and mutation induction in yeast; induction of pure mutant clones in yeast; radiosensitivity of bacteriophage T4; polyacrylamide gel electrophoresis of bacteriophage T4; radiation genetics of Dahibominus; and radiation studies on bitting flies. (HLW)

  14. Urate is a ligand for the transcriptional regulator PecS.

    Science.gov (United States)

    Perera, Inoka C; Grove, Anne

    2010-09-24

    PecS is a member of the MarR (multiple antibiotic resistance regulator) family, which has been shown in Erwinia to regulate the expression of virulence genes. MarR homologs typically bind a small molecule ligand, resulting in attenuated DNA binding. For PecS, the natural ligand has not been identified. We have previously shown that urate is a ligand for the Deinococcus radiodurans-encoded MarR homolog HucR (hypothetical uricase regulator) and identified residues responsible for ligand binding. We show here that all four residues involved in urate binding and propagation of conformational changes to DNA recognition helices are conserved in PecS homologs, suggesting that urate is the ligand for PecS. Consistent with this prediction, Agrobacterium tumefaciens PecS specifically binds urate, and urate attenuates DNA binding in vitro. PecS binds two operator sites in the intergenic region between the divergent pecS gene and pecM genes, one of which features two partially overlapping repeats to which PecS binds as a dimer on opposite faces of the duplex. Notably, urate dissociates PecS from cognate DNA, allowing transcription of both genes in vivo. Taken together, our data show that urate is a ligand for PecS and suggest that urate serves a novel function in signaling the colonization of a host plant. Copyright © 2010 Elsevier Ltd. All rights reserved.

  15. Protein function prediction involved on radio-resistant bacteria

    International Nuclear Information System (INIS)

    Mezhoud, Karim; Mankai, Houda; Sghaier, Haitham; Barkallah, Insaf

    2009-01-01

    Previously, we identified 58 proteins under positive selection in ionizing-radiation-resistant bacteria (IRRB) but absent in all ionizing-radiation-sensitive bacteria (IRSB). These are good reasons to believe these 58 proteins with their interactions with other proteins (interactomes) are a part of the answer to the question as to how IRRB resist to radiation, because our knowledge of interactomes of positively selected orphan proteins in IRRB might allow us to define cellular pathways important to ionizing-radiation resistance. Using the Database of Interacting Proteins and the PSIbase, we have predicted interactions of orthologs of the 58 proteins under positive selection in IRRB but absent in all IRSB. We used integrate experimental data sets with molecular interaction networks and protein structure prediction from databases. Among these, 18 proteins with their interactomes were identified in Deinococcus radiodurans R1. DNA checkpoint and repair, kinases pathways, energetic and nucleotide metabolisms were the important biological process that found. We predicted the interactomes of 58 proteins under positive selection in IRRB. It is hoped our data will provide new clues as to the cellular pathways that are important for ionizing-radiation resistance. We have identified news proteins involved on DNA management which were not previously mentioned. It is an important input in addition to protein that studied. It does still work to deepen our study on these new proteins

  16. Inactivation of bacterial spores by combination processes: ultraviolet plus gamma radiation. [Streptococcus faecium, micrococcus radiodurans, clostridium botulinum

    Energy Technology Data Exchange (ETDEWEB)

    Grecz, N; Durban, E

    1973-01-01

    Bacterial spores, viruses and some vegetative bacteria such as Streptococcus faecium and Micrococcus radiodurans are distinguished by high radiation resistance. In order to lay a theoretical basis for biomedical sterilization applications, we have investigated the combined action of uv and gamma rays. Spores of two strains of C. botulinum were selected, a highly radiation resistant strain, 33A having a D/sub 10/-value of 0.32 Mrad, and a relatively radiation sensitive strain, 51B having a D/sub 10/-value of 0.12 Mrad. Strain 33A exhibits an extensive initial ''shoulder'' in its uv as well as gamma ray survival curves; strain 51B shows only a slight shoulder. The shoulder in the gamma ray survival curve of spores of strain 33A could be reduced or completely eliminated by preirradiation with uv. Simultaneously the D/sub 10/-value for gamma inactivation of spores of 33A was reduced substantially. For example, the gamma resistance was reduced almost to half of its original D/sub 10/-value by uv-preirradiation for only one minute under an 8 watt GE germicidal lamp. The effect of uv-preirradiation on the radiation sensitive strain 51B was less pronounced. In fact, there was about seven fold higher positive interaction (synergism) between uv and gamma radiation in 33A spores than in 51B spores. The experiments suggest that interference with DNA repair enzymes in the radiation resistant strain are responsible for lethal synergism between uv and gamma radiation. A hypothesis is developed attempting to explain the combined effect of these two radiations in terms of a special summation of known DNA lesions in the cell. These observations emphasize the potential practical advantages of combining uv and gamma rays for effective sterilization of certain biomedical devices, drugs and biologicals.

  17. Physiological and molecular studies of the resistance to ionizing radiations of hyper-thermophilic archaea isolated from deep ocean hydrothermal sources

    International Nuclear Information System (INIS)

    Jolivet, E.

    2002-10-01

    In this study, we have first tested in vivo the effect of gamma irradiation on Pyrococcus abyssi, a hyper-thermophilic archaeon, isolated from a deep-sea hydrothermal vent. We have shown that this strain was as radioresistant as P. furiosus but less than Deinococcus radiodurans. The rates of double stranded breaks provoked into DNA following irradiation were monitored by the pulsed-field gel electrophoresis technique (P.F.G.E.) with P. abyssi, P. furiosus, D. radiodurans and Escherichia coli. Results clearly showed that all these rates were similar suggesting that no specific DNA protection system exits in Pyrococcus species. The growth of P. abyssi was efficiently recovered within two hours following the exposure to 2.5 kGy of gamma irradiation. As revealed by P.F.G.E., genomic DNA of P. abyssi totally fragmented after irradiation was efficiently restored within two hours presumably by inter chromosomal homologous recombination. The DNA replication in P. abyssi cells following irradiation at 2.5 kGy was blocked for 90 minutes that corresponds to the decay for repairing damaged DNA. Moreover, following irradiation P. abyssi actively expulse damaged DNA material before DNA replication resumes, preventing the amplification of genetic mutations. We have also showed that at least a subset cf P. abyssi DNA repair and replication proteins, such as RadA, RPA-41 and RFC-S. were constitutively expressed in chromatin bound forms in stationary phase cells. Our results were in agreement with the view that P. abyssi contains a very efficient DNA repair system, which is continuously ready to counteract the DNA damaged caused by the high temperature and/or ionizing radiation. For the first time, three novel hyper-thermophilic archaea species from deep-sea hydrothermal vents more radioresistant than P. abyssi were isolated and characterized, after 'y-irradiation exposures of some enrichment cultures. Thermococcus marinus, Thermococcus radiophilus and Thermococcus gammafolerans

  18. Bacterial biodiversity analysis of a contaminated soil from the Chernobyl exclusion zone and characterization of the committed interaction of a Microbacterium strain with uranium

    International Nuclear Information System (INIS)

    Theodorakopoulos, Nicolas

    2013-01-01

    The nuclear power plants accidents of Chernobyl and Fukushima demonstrate the importance of the understanding of the transfer of the radioactive contamination in the environment and its ecological consequences. Although certain studies have been realized on superior organisms of the food chain, studies on telluric bacterial communities are scarce. The latter play nevertheless an essential role in the mobility of contaminants in soils by decreasing or improving their transfer towards other compartments (water, vegetables and animals). Moreover radionuclides (RNs) can have toxic effects on bacteria, leading to an inhibition of their participation in such transfer. The objectives of this study were (1) to estimate the impact of the radioactive contamination on bacterial communities belonging to a soil of the Chernobyl exclusion zone (trench T22) and (2) to study the uranium-bacteria interactions of a resistant strain, isolated from this soil. The various techniques used to characterize the bacterial diversity (culture of bacteria, DGGE, 454 pyro-sequencing) all testified of the multiplicity and the abundance of the bacterial communities in spite of the contamination. An impact on the community structure was difficult to assess by DGGE or cultural approach, but was nevertheless highlighted by the use of pyro-sequencing, suggesting the presence of species more adapted to the contaminated soil conditions. A specific molecular tool dedicated to the search of bacteria affiliated to the known radiation resistant Deinococcus-Thermus phylum (for example the Deinococcus radiodurans specie survives after an irradiation of several kGy) was developed. However it did not reveal the presence of bacteria affiliated to such a phylum in the studied soil. In parallel to the study of the bacterial biodiversity, about fifty culturable bacteria were isolated from this site and were used as a support to select a species (Microbacterium) capable to survive strong U(VI) concentrations. The

  19. Preparation of monoclonal antibodies against radiation-induced protein

    International Nuclear Information System (INIS)

    Nozawa, R.; Tanaka, A.; Watanabe, H.; Kitayama, S.

    1992-01-01

    We obtained the 6 monoclonal antibodies against gamma-induced proteins of Deinococcus radiodurans, and these antibodies were designated as Mab-3F, 4B, 4D, 4F, 4G and 12G. Using these antibodies, we investigated the relations between gamma-induced proteins and other stress protein in strain R1, and the induction of proteins were compared among strain R1, resistant mutant (rec1) and radiosensitive mutant (rec30). We found new 6 proteins recognized by these monoclonal antibodies which were induced after gamma-irradiation especially in strain R1 and rec 1, but not induced in strain rec30. We suppose that these proteins participate in repair of DNA damages including double strand breaks caused by gamma-irradiation. One of them was around 46kDa protein band recognized by Mab-12G, and this protein was so induced in a large quantity after irradiation that the protein could detect by gold staining. In addition to this observation, we found some proteins which were induced in R1 and rec 1 by gamma-irradiation and other stress, but not in strain rec30, such as 31kDa protein band recognized by Mab-3F, 4B and 4G, and other 11 proteins which were especially induced in irradiated strain R1. The latter proteins might be reinforcement factor to radioresistance such as GroE and DnaK, or participant in repair of damage by gamma-irradiation in strain R1. (author)

  20. NCBI nr-aa BLAST: CBRC-GACU-09-0002 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available CBRC-GACU-09-0002 ref|YP_594114.1| amidohydrolase [Deinococcus geothermalis DSM 113...00] gb|ABF44040.1| amidohydrolase [Deinococcus geothermalis DSM 11300] YP_594114.1 5.5 28% ...

  1. Bioremediation/Biorecovery of uranium from aquatic resource/waste: the Cyano-Deino story

    International Nuclear Information System (INIS)

    Apte, Shree Kumar

    2015-01-01

    Terrestrial sources of uranium are getting depleted fast and may be exhausted in the next few decades. This has triggered a search for alternate or secondary resources for this precious metal. Nearly 4.5 billion tons of uranium on our planet resides in seawater, albeit at very low concentrations of 3 ppb. Recovering uranium from such low concentrations is a major challenge. Two marine cyanobacteria, the unicellular Synechococcus elongatus and the filamentous Anabaena torulosa, were found to be capable of rapidly sequestering uranyl carbonate (the predominant uranyl species at the sea-water pH of 7.8) from aqueous solutions, including simulated sea-water. While Synechococcus strain adsorbed the metal as carbonato complexes on cell surface ligands, A. torulosa trapped it in novel surface-associated polyphosphate bodies. The uranium binding potential of cyanobacterial biomass was comparable to, if not better than, the currently in use polyamidoxime resin. The bound uranium could be desorbed easily and the biomass reused a few times. The method has eminently higher application potential in uranium-contaminated terrestrial waters, where the metal concentration is several times higher. Low concentrations (<1 to few mM) of uranium are also found in acidic/alkaline nuclear waste and arise from metal extraction or during reprocessing of fuel. Removal of uranium from such solutions is very desirable for safer disposal of such waste. Biological agents to be employed in such situations also need to be tolerant to and stable in high radiation environments, unless dead cells can be used. To address such bioremediation, the extremely radio-resistant microbe Deinococcus radiodurans was genetically engineered to express either a non-specific acid phosphatase PhoN or a highly active novel alkaline phosphatase PhoK. Apart from the need for high expression of desired protein, such engineering is also fraught with problems of stability, localization and activity of the expressed

  2. NCBI nr-aa BLAST: CBRC-PTRO-15-0056 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available CBRC-PTRO-15-0056 ref|YP_605216.1| hypothetical protein Dgeo_1752 [Deinococcus geothermal...is DSM 11300] gb|ABF46047.1| hypothetical protein Dgeo_1752 [Deinococcus geothermalis DSM 11300] YP_605216.1 0.001 28% ...

  3. NCBI nr-aa BLAST: CBRC-OANA-01-0785 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available CBRC-OANA-01-0785 ref|YP_603809.1| hypothetical protein Dgeo_0337 [Deinococcus geothermal...is DSM 11300] gb|ABF44640.1| hypothetical protein Dgeo_0337 [Deinococcus geothermalis DSM 11300] YP_603809.1 1.8 32% ...

  4. NCBI nr-aa BLAST: CBRC-LAFR-01-1366 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available CBRC-LAFR-01-1366 ref|YP_604712.1| cytochrome c assembly protein [Deinococcus geothermal...is DSM 11300] gb|ABF45543.1| cytochrome c assembly protein [Deinococcus geothermalis DSM 11300] YP_604712.1 2.0 30% ...

  5. NCBI nr-aa BLAST: CBRC-ACAR-01-0712 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available CBRC-ACAR-01-0712 ref|YP_604712.1| cytochrome c assembly protein [Deinococcus geothermal...is DSM 11300] gb|ABF45543.1| cytochrome c assembly protein [Deinococcus geothermalis DSM 11300] YP_604712.1 7.8 32% ...

  6. NCBI nr-aa BLAST: CBRC-LAFR-01-2025 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available CBRC-LAFR-01-2025 ref|YP_605433.1| hypothetical protein Dgeo_1970 [Deinococcus geothermal...is DSM 11300] gb|ABF46264.1| hypothetical protein Dgeo_1970 [Deinococcus geothermalis DSM 11300] YP_605433.1 0.15 38% ...

  7. NCBI nr-aa BLAST: CBRC-LAFR-01-0180 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available CBRC-LAFR-01-0180 ref|YP_605433.1| hypothetical protein Dgeo_1970 [Deinococcus geothermal...is DSM 11300] gb|ABF46264.1| hypothetical protein Dgeo_1970 [Deinococcus geothermalis DSM 11300] YP_605433.1 0.15 38% ...

  8. NCBI nr-aa BLAST: CBRC-CJAC-01-0283 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available CBRC-CJAC-01-0283 ref|YP_593975.1| hypothetical protein Dgeo_2467 [Deinococcus geothermal...is DSM 11300] gb|ABF43901.1| hypothetical protein Dgeo_2467 [Deinococcus geothermalis DSM 11300] YP_593975.1 5e-10 28% ...

  9. NCBI nr-aa BLAST: CBRC-LAFR-01-1215 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available CBRC-LAFR-01-1215 ref|YP_605765.1| major facilitator superfamily MFS_1 [Deinococcus geothermal...is DSM 11300] gb|ABF46596.1| major facilitator superfamily MFS_1 [Deinococcus geothermalis DSM 11300] YP_605765.1 0.67 28% ...

  10. NCBI nr-aa BLAST: CBRC-XTRO-01-2352 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available CBRC-XTRO-01-2352 ref|YP_605707.1| major facilitator superfamily MFS_1 [Deinococcus geothermal...is DSM 11300] gb|ABF46538.1| major facilitator superfamily MFS_1 [Deinococcus geothermalis DSM 11300] YP_605707.1 0.86 29% ...

  11. NCBI nr-aa BLAST: CBRC-OANA-01-0840 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available CBRC-OANA-01-0840 ref|YP_605770.1| protein of unknown function DUF422 [Deinococcus geothermal...is DSM 11300] gb|ABF46601.1| protein of unknown function DUF422 [Deinococcus geothermalis DSM 11300] YP_605770.1 3.6 34% ...

  12. NCBI nr-aa BLAST: CBRC-LAFR-01-0684 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available CBRC-LAFR-01-0684 ref|YP_605770.1| protein of unknown function DUF422 [Deinococcus geothermal...is DSM 11300] gb|ABF46601.1| protein of unknown function DUF422 [Deinococcus geothermalis DSM 11300] YP_605770.1 3.2 25% ...

  13. Diversity of 23S rRNA genes within individual prokaryotic genomes.

    Directory of Open Access Journals (Sweden)

    Anna Pei

    Full Text Available BACKGROUND: The concept of ribosomal constraints on rRNA genes is deduced primarily based on the comparison of consensus rRNA sequences between closely related species, but recent advances in whole-genome sequencing allow evaluation of this concept within organisms with multiple rRNA operons. METHODOLOGY/PRINCIPAL FINDINGS: Using the 23S rRNA gene as an example, we analyzed the diversity among individual rRNA genes within a genome. Of 184 prokaryotic species containing multiple 23S rRNA genes, diversity was observed in 113 (61.4% genomes (mean 0.40%, range 0.01%-4.04%. Significant (1.17%-4.04% intragenomic variation was found in 8 species. In 5 of the 8 species, the diversity in the primary structure had only minimal effect on the secondary structure (stem versus loop transition. In the remaining 3 species, the diversity significantly altered local secondary structure, but the alteration appears minimized through complex rearrangement. Intervening sequences (IVS, ranging between 9 and 1471 nt in size, were found in 7 species. IVS in Deinococcus radiodurans and Nostoc sp. encode transposases. T. tengcongensis was the only species in which intragenomic diversity >3% was observed among 4 paralogous 23S rRNA genes. CONCLUSIONS/SIGNIFICANCE: These findings indicate tight ribosomal constraints on individual 23S rRNA genes within a genome. Although classification using primary 23S rRNA sequences could be erroneous, significant diversity among paralogous 23S rRNA genes was observed only once in the 184 species analyzed, indicating little overall impact on the mainstream of 23S rRNA gene-based prokaryotic taxonomy.

  14. Geomicrobiology of High Level Nuclear Waste-Contaminated Vadose Sediments at the Hanford Site, Washington State

    International Nuclear Information System (INIS)

    Fredrickson, Jim K.; Zachara, John M.; Balkwill, David L.; Kennedy, David W.; Li, Shu-Mei W.; Kostandarithes, Heather M.; Daly, Michael J.; Romine, Margaret F.; Brockman, Fred J.

    2004-01-01

    Sediments from a high-level nuclear waste plume were collected as part of investigations to evaluate the potential fate and migration of contaminants in the subsurface. The plume originated from a leak that occurred in 1962 from a waste tank consisting of high concentrations of alkali, nitrate, aluminate, Cr(VI), 137Cs, and 99Tc. Investigations were initiated to determine the distribution of viable microorganisms in the vadose sediment samples, probe the phylogeny of cultivated and uncultivated members, and evaluate the ability of the cultivated organisms to survive acute doses of ionizing radiation. The populations of viable aerobic heterotrophic bacteria were generally low, from below detection to ∼104 7 CFU g-1 but viable microorganisms were recovered from 11 of 16 samples including several of the most radioactive ones (e.g., > 10 ?Ci/g 137Cs). The isolates from the contaminated sediments and clone libraries from sediment DNA extracts were dominated by members related to known Gram-positive bacteria. Gram-positive bacteria most closely related to Arthrobacter species were the most common isolates among all samples but other high G+C phyla were also represented including Rhodococcus and Nocardia. Two isolates from the second most radioactive sample (>20 ?Ci 137Cs g-1) were closely related to Deinococcus radiodurans and were able to survive acute doses of ionizing radiation approaching 20kGy. Many of the Gram-positive isolates were resistant to lower levels of gamma radiation. These results demonstrate that Gram-positive bacteria, predominantly high G+C phyla, are indigenous to Hanford vadose sediments and some are effective at surviving the extreme physical and chemical stress associated with radioactive waste

  15. Limit for the Survivability from Potassium Decay of Bacterial Spores in Halite Fluid Inclusions

    Science.gov (United States)

    Kminek, G.; Bada, J. L.

    2001-12-01

    DNA damage-tolerant organism known today is Deinococcus radiodurans. The viability of D. radiodurans falls to undetectable levels6 at about 18 kGy. The survival curve of dry Bacillus megaterium spores shows a 4-log reduction at about 8-10 kGy7,8. These numbers can be compared to the 87 kGy in the case for a Permian fluid inclusion. The ability to tolerate radiation induced damage lies in the efficient repair mechanism employed by D. radiodurans, which is not operative in a dormant spore. It would thus be highly unusual for a bacterial spore to survive intact for 100's of millions of years unless these bacteria are extremely radiation tolerant. Based on these considerations and without active DNA repair mechanisms, viability of a dormant bacterial spore and the survival of viable genetic material over extended periods of geologic time is probably limited by exposure to natural background radiation. 1. Vreeland, R. H., Rosenzweig, W. D., Powers, D. W. Nature 407, 897-900 (2000) 2. Cano, P. J., Borucki, M. K. Science 268, 1060-1064 (1995) 3. Parkes, R. J.Nature, 407, 844-845 (2000) 4. Lindahl, T. Nature 362, 709-715 (1993) 5. Setlow, P. J. Bacteriol., 174 (9), 2737-2741 (1992) 6. Battista, J. R. Annu. Rev. Micriobiol. 51, 203-224 (1997) 7. Powers, E. L., Kaleta, B. F. Science 132, 959-960 (1960) 8. Ewing, D., Powers, E. L. Science 194, 1049-1051 (1976)

  16. Bacterial and archaeal resistance to ionizing radiation

    Energy Technology Data Exchange (ETDEWEB)

    Confalonieri, F; Sommer, S, E-mail: fabrice.confalonieri@u-psud.fr, E-mail: suzanne.sommer@u-psud.fr [University Paris-Sud, CNRS UMR8621, Institut de Genetique et Microbiologie, Batiments 400-409, Universite Paris-Sud, 91405 Orsay (France)

    2011-01-01

    Organisms living in extreme environments must cope with large fluctuations of temperature, high levels of radiation and/or desiccation, conditions that can induce DNA damage ranging from base modifications to DNA double-strand breaks. The bacterium Deinococcus radiodurans is known for its resistance to extremely high doses of ionizing radiation and for its ability to reconstruct a functional genome from hundreds of radiation-induced chromosomal fragments. Recently, extreme ionizing radiation resistance was also generated by directed evolution of an apparently radiation-sensitive bacterial species, Escherichia coli. Radioresistant organisms are not only found among the Eubacteria but also among the Archaea that represent the third kingdom of life. They present a set of particular features that differentiate them from the Eubacteria and eukaryotes. Moreover, Archaea are often isolated from extreme environments where they live under severe conditions of temperature, pressure, pH, salts or toxic compounds that are lethal for the large majority of living organisms. Thus, Archaea offer the opportunity to understand how cells are able to cope with such harsh conditions. Among them, the halophilic archaeon Halobacterium sp and several Pyrococcus or Thermococcus species, such as Thermococcus gammatolerans, were also shown to display high level of radiation resistance. The dispersion, in the phylogenetic tree, of radioresistant prokaryotes suggests that they have independently acquired radioresistance. Different strategies were selected during evolution including several mechanisms of radiation byproduct detoxification and subtle cellular metabolism modifications to help cells recover from radiation-induced injuries, protection of proteins against oxidation, an efficient DNA repair tool box, an original pathway of DNA double-strand break repair, a condensed nucleoid that may prevent the dispersion of the DNA fragments and specific radiation-induced proteins involved in

  17. Phosphinothricin Acetyltransferases Identified Using In Vivo, In Vitro, and Bioinformatic Analyses

    Science.gov (United States)

    VanDrisse, Chelsey M.; Hentchel, Kristy L.

    2016-01-01

    ABSTRACT Acetylation of small molecules is widespread in nature, and in some cases, cells use this process to detoxify harmful chemicals. Streptomyces species utilize a Gcn5 N-acetyltransferase (GNAT), known as Bar, to acetylate and detoxify a self-produced toxin, phosphinothricin (PPT), a glutamate analogue. Bar homologues, such as MddA from Salmonella enterica, acetylate methionine analogues such as methionine sulfoximine (MSX) and methionine sulfone (MSO), but not PPT, even though Bar homologues are annotated as PPT acetyltransferases. S. enterica was used as a heterologous host to determine whether or not putative PPT acetyltransferases from various sources could acetylate PPT, MSX, and MSO. In vitro and in vivo analyses identified substrates acetylated by putative PPT acetyltransferases from Deinococcus radiodurans (DR_1057 and DR_1182) and Geobacillus kaustophilus (GK0593 and GK2920). In vivo, synthesis of DR_1182, GK0593, and GK2920 blocked the inhibitory effects of PPT, MSX, and MSO. In contrast, DR_1057 did not detoxify any of the above substrates. Results of in vitro studies were consistent with the in vivo results. In addition, phylogenetic analyses were used to predict the functionality of annotated PPT acetyltransferases in Burkholderia xenovorans, Bacillus subtilis, Staphylococcus aureus, Acinetobacter baylyi, and Escherichia coli. IMPORTANCE The work reported here provides an example of the use of a heterologous system for the identification of enzyme function. Many members of this superfamily of proteins do not have a known function, or it has been annotated solely on the basis of sequence homology to previously characterized enzymes. The critical role of Gcn5 N-acetyltransferases (GNATs) in the modulation of central metabolic processes, and in controlling metabolic stress, necessitates approaches that can reveal their physiological role. The combination of in vivo, in vitro, and bioinformatics approaches reported here identified GNATs that can

  18. On the Stability of Deinoxanthin Exposed to Mars Conditions during a Long-Term Space Mission and Implications for Biomarker Detection on Other Planets

    Directory of Open Access Journals (Sweden)

    Stefan Leuko

    2017-09-01

    Full Text Available Outer space, the final frontier, is a hostile and unforgiving place for any form of life as we know it. The unique environment of space allows for a close simulation of Mars surface conditions that cannot be simulated as accurately on the Earth. For this experiment, we tested the resistance of Deinococcus radiodurans to survive exposure to simulated Mars-like conditions in low-Earth orbit for a prolonged period of time as part of the Biology and Mars experiment (BIOMEX project. Special focus was placed on the integrity of the carotenoid deinoxanthin, which may serve as a potential biomarker to search for remnants of life on other planets. Survival was investigated by evaluating colony forming units, damage inflicted to the 16S rRNA gene by quantitative PCR, and the integrity and detectability of deinoxanthin by Raman spectroscopy. Exposure to space conditions had a strong detrimental effect on the survival of the strains and the 16S rRNA integrity, yet results show that deinoxanthin survives exposure to conditions as they prevail on Mars. Solar radiation is not only strongly detrimental to the survival and 16S rRNA integrity but also to the Raman signal of deinoxanthin. Samples not exposed to solar radiation showed only minuscule signs of deterioration. To test whether deinoxanthin is able to withstand the tested parameters without the protection of the cell, it was extracted from cell homogenate and exposed to high/low temperatures, vacuum, germicidal UV-C radiation, and simulated solar radiation. Results obtained by Raman investigations showed a strong resistance of deinoxanthin against outer space and Mars conditions, with the only exception of the exposure to simulated solar radiation. Therefore, deinoxanthin proved to be a suitable easily detectable biomarker for the search of Earth-like organic pigment-containing life on other planets.

  19. Study of the impact of environmental bacteria ob uranium speciation in order to engage bioremediation process

    International Nuclear Information System (INIS)

    Untereiner, G.

    2008-11-01

    Uranium is both a radiological and a chemical toxic. Its concentration in the environment is low except when human activities have caused pollution. Uranium is a heavy reactive element, and thus it is easily complexed with soil component like minerals or organic molecules. These different complexes can be more or less bioavailable for microorganisms and plants, and then get in the human food chain. The knowledge and the understanding of transfer mechanisms and also the fate of toxic elements in the biosphere are a key issue to estimate health and ecological hazards. The knowledge of the speciation is very important for bioremediation processes. Here, we focused on the microorganisms effects onto uranium speciation in environment. Bacteria can accumulate and/or transform uranium depending on the initial form of the element. Thus, its bioavailability could be changed. The species used in this work are Cupriavidus metallidurans CH34, which is an environmental bacteria with a high resistance to heavy metal, Deinococcus radiodurans R1, which is known for his radiological resistance, and Rhodopseudomonas palustris, which is a purple photo-trophic bacteria capable of degrading aromatic compounds. Two forms of uranium were used with these bacteria, a mineral one, uranyl carbonate, and an organic one, uranyl citrate. In a first step, the growth media were modified in order to stabilize uranium complexes thanks to a simulation program. Then, the capacity of the bacteria to accumulate or transform uranium was studied. We saw a difference between minimal inhibition concentrations of these two speciation which is due to a difference between phosphate bioavailability. No accumulation was observed with environmental pH but uranium precipitation was observed with acidic pH (pH 1). Uranium speciation seemed to be well controlled in the growth media and the precipitates were uranyl phosphate. (author)

  20. ORF Alignment: NC_001264 [GENIUS II[Archive

    Lifescience Database Archive (English)

    Full Text Available einococcus radiodurans (strain ... R1) ... Length = 233 ... Query: 7 ... TVEQAVRVLEYFDADHT...EWTLSDLARALALPTSTLHEQLSTLTASGLLRRTGRGRYQLGW 66 ... TVEQAVRVLEYFDADHTEWTLSDLARALALPT...STLHEQLSTLTASGLLRRTGRGRYQLGW Sbjct: 1 ... TVEQAVRVLEYFDADHTEWTLSDLARALALPTSTLHEQLSTLTASGLLRRTGRGRYQLGW 60 ... Que

  1. The microbe capture experiment in space: Fluorescence microscopic detection of microbes captured by aerogel

    Science.gov (United States)

    Sugino, Tomohiro; Yokobori, Shin-Ichi; Yang, Yinjie; Kawaguchi, Yuko; Okudaira, Kyoko; Tabata, Makoto; Kawai, Hideyuki; Hasegawa, Sunao; Yamagishi, Akihiko

    particles such as clay). The surface of micro-particles captured by aerogel is often vitrified. The non-specific fluorescent light is often observed from vitrified materials. Therefore, we need to distinguish fluorescent light of stained microbes from that of vitrified ma-terials. We are going to use two types of differences (wavelength dependence and attenuation rate of fluorescent) between stained microbes with DNA-specific fluorescent dye and other ma-terials such as clay and aerogel. Fluorescent light of stained microbes shows attenuation faster than that of vitrified materials. Fluorescent light of vitrified materials shows broader range of emission spectra than that of stained microbes. In addition, we simulated the high-speed collision experiment of micro-particles to the aerogel with the two stage light gas gun (ca. 4 km/s). The micro-particles containing pre-stained and dried cells of Deinococcus radiodurans mixed with clay material were used for the collision experiment, and the captured particles were observed with fluorescence microscope. This experiment suggests that the captured microbes can be detected and be distinguished from clay materials. Reference [1] Yang, Y. et al. (2009) Biol. Sci. Space, 23, 151-163. [2] Yang, Y., et al. (2008) Biol. Sci. Space 22:18-25. [3] Yang, Y., et al. (2008) JAXA-RR-08-001: 34-42. [4] Yang, Y., et al. (2009) Internatl. J. Syst. Evol. Bacteriol., 59: 1862-1866. [5] Yang, Y. et al. (2010) Internatl. J. Syst. Evol. Bacteriol. (in press). [6] Arrhenius, S. (1908) Worlds in the Making-the Evolution of the Universe (translation to English by H. Borns) Harper and Brothers Publishers, New York. [7]Crick, F. (1981) Life Itself. Simon Schuster, New York. [8] W.L. Nicholson et al., Microbiol. Mol. Biol. Rev. 64 (2000) 548. [9] G. Horneck et al., Orig. Life Evol. Biosph. 31 (2001) 527. [10] Chyba, C. and C. Sagan (1992) Nature 355: 125-132. [11] Sandford, S. A., et al. (2006) Science 314: 1720-1724. [12] Yamagishi, A., et al. (2008

  2. International Conference on Software Engineering, Knowledge Engineering and Information Engineering (SEKEIE 2012)

    CERN Document Server

    Software Engineering and Knowledge Engineering: Theory and Practice

    2012-01-01

    2012 International Conference on Software Engineering, Knowledge Engineering and Information Engineering (SEKEIE 2012) will be held in Macau, April 1-2, 2012 . This conference will bring researchers and experts from the three areas of Software Engineering, Knowledge Engineering and Information Engineering together to share their latest research results and ideas.   This volume book covered significant recent developments in the Software Engineering, Knowledge Engineering and Information Engineering field, both theoretical and applied. We are glad this conference attracts your attentions, and thank your support to our conference. We will absorb remarkable suggestion, and make our conference more successful and perfect.

  3. Micro-organisms and divers exposure to radioactivity in spent fuel pools at nuclear power plants

    Energy Technology Data Exchange (ETDEWEB)

    Muniz de A, D. [Underwater Construction Corporation, Latin America, Fortaleza, Ceara (Brazil); Silva, R. [Universidade Federal do Rio de Janeiro, Instituto de Biofisica Carlos Chagas Filho, 21941-902 Rio de Janeiro (Brazil); Gomes N, C. A., E-mail: dmuniz@uccdive.com [Universidade Federal do Rio de Janeiro, Instituto de Biologia, Environmental Engineering Program, 21941-902 Rio de Janeiro (Brazil)

    2017-09-15

    Many nuclear power plants (NPPs) around the world are in the process of extending their lifespan from 40 to 60 years of operation. The NPP; Angra 1 (Brazil) has performed a thorough evaluation of its Life Extension Engineering project. In this context, the spent fuel pool (SFP) was one of the areas studied in order to demonstrate the plants integrity for a life extension. Micro-organisms growing on the liner of the fuel transfer channel (Ftc) and SFP can form a film of bacteria, which is highly resistant to radiation. This paper aims to compare the micro-organisms found in NPP Angra 1 with those reported to other NPPs and also relates their occurrence with the radiation levels at the sites. It also compares divers exposure to radioactivity during underwater activities in the SFP. Fourteen samples were collected on the surface of the liners of the Ftc, the SFP and the drains within the fuel building (FB) of Angra 1. For the identification of the micro-organisms, a metagenomics analysis was performed by random sequencing (Shotgun) and the use of Ion Torrent PGM Sequence r. Twelve micro-organisms phyla were identified; Acido-bacteria, Actino-bacteria, Bacteroidetes, Chlamydiae, Chlorobi, Chloroflexi, Cyano-bacteria, Deinococcus-Thermus, Firmicutes, Planctomycetes, Proteo-bacteria, and Verrucomicrobia as well as organisms not classified. In the SFP of Angra 1, the bacteria survived the exposure to a radiation of 0.416 Gy/h (high radiation). Deinococcus-thermus, bacteria identified in Angra 1, has resisted an exposure to 30,000 Gy/h in another plant. (Author)

  4. Micro-organisms and divers exposure to radioactivity in spent fuel pools at nuclear power plants

    International Nuclear Information System (INIS)

    Muniz de A, D.; Silva, R.; Gomes N, C. A.

    2017-09-01

    Many nuclear power plants (NPPs) around the world are in the process of extending their lifespan from 40 to 60 years of operation. The NPP; Angra 1 (Brazil) has performed a thorough evaluation of its Life Extension Engineering project. In this context, the spent fuel pool (SFP) was one of the areas studied in order to demonstrate the plants integrity for a life extension. Micro-organisms growing on the liner of the fuel transfer channel (Ftc) and SFP can form a film of bacteria, which is highly resistant to radiation. This paper aims to compare the micro-organisms found in NPP Angra 1 with those reported to other NPPs and also relates their occurrence with the radiation levels at the sites. It also compares divers exposure to radioactivity during underwater activities in the SFP. Fourteen samples were collected on the surface of the liners of the Ftc, the SFP and the drains within the fuel building (FB) of Angra 1. For the identification of the micro-organisms, a metagenomics analysis was performed by random sequencing (Shotgun) and the use of Ion Torrent PGM Sequence r. Twelve micro-organisms phyla were identified; Acido-bacteria, Actino-bacteria, Bacteroidetes, Chlamydiae, Chlorobi, Chloroflexi, Cyano-bacteria, Deinococcus-Thermus, Firmicutes, Planctomycetes, Proteo-bacteria, and Verrucomicrobia as well as organisms not classified. In the SFP of Angra 1, the bacteria survived the exposure to a radiation of 0.416 Gy/h (high radiation). Deinococcus-thermus, bacteria identified in Angra 1, has resisted an exposure to 30,000 Gy/h in another plant. (Author)

  5. Infrared fluorescent protein 1.4 genetic labeling tracks engrafted cardiac progenitor cells in mouse ischemic hearts.

    Directory of Open Access Journals (Sweden)

    Lijuan Chen

    Full Text Available Stem cell therapy has a potential for regenerating damaged myocardium. However, a key obstacle to cell therapy's success is the loss of engrafted cells due to apoptosis or necrosis in the ischemic myocardium. While many strategies have been developed to improve engrafted cell survival, tools to evaluate cell efficacy within the body are limited. Traditional genetic labeling tools, such as GFP-like fluorescent proteins (eGFP, DsRed, mCherry, have limited penetration depths in vivo due to tissue scattering and absorption. To circumvent these limitations, a near-infrared fluorescent mutant of the DrBphP bacteriophytochrome from Deinococcus radiodurans, IFP1.4, was developed for in vivo imaging, but it has yet to be used for in vivo stem/progenitor cell tracking. In this study, we incorporated IFP1.4 into mouse cardiac progenitor cells (CPCs by a lentiviral vector. Live IFP1.4-labeled CPCs were imaged by their near-infrared fluorescence (NIRF using an Odyssey scanner following overnight incubation with biliverdin. A significant linear correlation was observed between the amount of cells and NIRF signal intensity in in vitro studies. Lentiviral mediated IFP1.4 gene labeling is stable, and does not impact the apoptosis and cardiac differentiation of CPC. To assess efficacy of our model for engrafted cells in vivo, IFP1.4-labeled CPCs were intramyocardially injected into infarcted hearts. NIRF signals were collected at 1-day, 7-days, and 14-days post-injection using the Kodak in vivo multispectral imaging system. Strong NIRF signals from engrafted cells were imaged 1 day after injection. At 1 week after injection, 70% of the NIRF signal was lost when compared to the intensity of the day 1 signal. The data collected 2 weeks following transplantation showed an 88% decrease when compared to day 1. Our studies have shown that IFP1.4 gene labeling can be used to track the viability of transplanted cells in vivo.

  6. A computational approach to discovering the functions of bacterial phytochromes by analysis of homolog distributions

    Directory of Open Access Journals (Sweden)

    Lamparter Tilman

    2006-03-01

    Full Text Available Abstract Background Phytochromes are photoreceptors, discovered in plants, that control a wide variety of developmental processes. They have also been found in bacteria and fungi, but for many species their biological role remains obscure. This work concentrates on the phytochrome system of Agrobacterium tumefaciens, a non-photosynthetic soil bacterium with two phytochromes. To identify proteins that might share common functions with phytochromes, a co-distribution analysis was performed on the basis of protein sequences from 138 bacteria. Results A database of protein sequences from 138 bacteria was generated. Each sequence was BLASTed against the entire database. The homolog distribution of each query protein was then compared with the homolog distribution of every other protein (target protein of the same species, and the target proteins were sorted according to their probability of co-distribution under random conditions. As query proteins, phytochromes from Agrobacterium tumefaciens, Pseudomonas aeruginosa, Deinococcus radiodurans and Synechocystis PCC 6803 were chosen along with several phytochrome-related proteins from A. tumefaciens. The Synechocystis photosynthesis protein D1 was selected as a control. In the D1 analyses, the ratio between photosynthesis-related proteins and those not related to photosynthesis among the top 150 in the co-distribution tables was > 3:1, showing that the method is appropriate for finding partner proteins with common functions. The co-distribution of phytochromes with other histidine kinases was remarkably high, although most co-distributed histidine kinases were not direct BLAST homologs of the query protein. This finding implies that phytochromes and other histidine kinases share common functions as parts of signalling networks. All phytochromes tested, with one exception, also revealed a remarkably high co-distribution with glutamate synthase and methionine synthase. This result implies a general role of

  7. Assessing fluctuating evolutionary pressure in yeast and mammal evolutionary rate covariation using bioinformatics of meiotic protein genetic sequences

    Science.gov (United States)

    Dehipawala, Sunil; Nguyen, A.; Tremberger, G.; Cheung, E.; Holden, T.; Lieberman, D.; Cheung, T.

    2013-09-01

    The evolutionary rate co-variation in meiotic proteins has been reported for yeast and mammal using phylogenic branch lengths which assess retention, duplication and mutation. The bioinformatics of the corresponding DNA sequences could be classified as a diagram of fractal dimension and Shannon entropy. Results from biomedical gene research provide examples on the diagram methodology. The identification of adaptive selection using entropy marker and functional-structural diversity using fractal dimension would support a regression analysis where the coefficient of determination would serve as evolutionary pathway marker for DNA sequences and be an important component in the astrobiology community. Comparisons between biomedical genes such as EEF2 (elongation factor 2 human, mouse, etc), WDR85 in epigenetics, HAR1 in human specificity, clinical trial targeted cancer gene CD47, SIRT6 in spermatogenesis, and HLA-C in mosquito bite immunology demonstrate the diagram classification methodology. Comparisons to the SEPT4-XIAP pair in stem cell apoptosis, testesexpressed taste genes TAS1R3-GNAT3 pair, and amyloid beta APLP1-APLP2 pair with the yeast-mammal DNA sequences for meiotic proteins RAD50-MRE11 pair and NCAPD2-ICK pair have accounted for the observed fluctuating evolutionary pressure systematically. Regression with high R-sq values or a triangular-like cluster pattern for concordant pairs in co-variation among the studied species could serve as evidences for the possible location of common ancestors in the entropy-fractal dimension diagram, consistent with an example of the human-chimp common ancestor study using the FOXP2 regulated genes reported in human fetal brain study. The Deinococcus radiodurans R1 Rad-A could be viewed as an outlier in the RAD50 diagram and also in the free energy versus fractal dimension regression Cook's distance, consistent with a non-Earth source for this radiation resistant bacterium. Convergent and divergent fluctuating evolutionary

  8. Alterations at the peptidyl transferase centre of the ribosome induced by the synergistic action of the streptogramins dalfopristin and quinupristin

    Directory of Open Access Journals (Sweden)

    Fucini Paola

    2004-04-01

    Full Text Available Abstract Background The bacterial ribosome is a primary target of several classes of antibiotics. Investigation of the structure of the ribosomal subunits in complex with different antibiotics can reveal the mode of inhibition of ribosomal protein synthesis. Analysis of the interactions between antibiotics and the ribosome permits investigation of the specific effect of modifications leading to antimicrobial resistances. Streptogramins are unique among the ribosome-targeting antibiotics because they consist of two components, streptogramins A and B, which act synergistically. Each compound alone exhibits a weak bacteriostatic activity, whereas the combination can act bactericidal. The streptogramins A display a prolonged activity that even persists after removal of the drug. However, the mode of activity of the streptogramins has not yet been fully elucidated, despite a plethora of biochemical and structural data. Results The investigation of the crystal structure of the 50S ribosomal subunit from Deinococcus radiodurans in complex with the clinically relevant streptogramins quinupristin and dalfopristin reveals their unique inhibitory mechanism. Quinupristin, a streptogramin B compound, binds in the ribosomal exit tunnel in a similar manner and position as the macrolides, suggesting a similar inhibitory mechanism, namely blockage of the ribosomal tunnel. Dalfopristin, the corresponding streptogramin A compound, binds close to quinupristin directly within the peptidyl transferase centre affecting both A- and P-site occupation by tRNA molecules. Conclusions The crystal structure indicates that the synergistic effect derives from direct interaction between both compounds and shared contacts with a single nucleotide, A2062. Upon binding of the streptogramins, the peptidyl transferase centre undergoes a significant conformational transition, which leads to a stable, non-productive orientation of the universally conserved U2585. Mutations of this r

  9. Engineering Encounters: Engineering Adaptations

    Science.gov (United States)

    Gatling, Anne; Vaughn, Meredith Houle

    2015-01-01

    Engineering is not a subject that has historically been taught in elementary schools, but with the emphasis on engineering in the "Next Generation Science Standards," curricula are being developed to explicitly teach engineering content and design. However, many of the scientific investigations already conducted with students have…

  10. 40 CFR 90.116 - Certification procedure-determining engine displacement, engine class, and engine families.

    Science.gov (United States)

    2010-07-01

    ... engine displacement, engine class, and engine families. 90.116 Section 90.116 Protection of Environment...-IGNITION ENGINES AT OR BELOW 19 KILOWATTS Emission Standards and Certification Provisions § 90.116 Certification procedure—determining engine displacement, engine class, and engine families. (a) Engine...

  11. Sound engineering for diesel engines; Sound Engineering an Dieselmotoren

    Energy Technology Data Exchange (ETDEWEB)

    Enderich, A.; Fischer, R. [MAHLE Filtersysteme GmbH, Stuttgart (Germany)

    2006-07-01

    The strong acceptance for vehicles powered by turbo-charged diesel engines encourages several manufacturers to think about sportive diesel concepts. The approach of suppressing unpleasant noise by the application of distinctive insulation steps is not adequate to satisfy sportive needs. The acoustics cannot follow the engine's performance. This report documents, that it is possible to give diesel-powered vehicles a sportive sound characteristic by using an advanced MAHLE motor-sound-system with a pressure-resistant membrane and an integrated load controlled flap. With this the specific acoustic disadvantages of the diesel engine, like the ''diesel knock'' or a rough engine running can be masked. However, by the application of a motor-sound-system you must not negate the original character of the diesel engine concept, but accentuate its strong torque characteristic in the middle engine speed range. (orig.)

  12. Engineering justice transforming engineering education and practice

    CERN Document Server

    Leydens, Jon A

    2018-01-01

    Using social justice as a catalyst for curricular transformation, Engineering Justice presents an examination of how politics, culture, and other social issues are inherent in the practice of engineering. It aims to align engineering curricula with socially just outcomes, increase enrollment among underrepresented groups, and lessen lingering gender, class, and ethnicity gaps by showing how the power of engineering knowledge can be explicitly harnessed to serve the underserved and address social inequalities. This book is meant to transform the way educators think about engineering curricula through creating or transforming existing courses to attract, retain, and motivate engineering students to become professionals who enact engineering for social justice. Engineering Justice offers thought-provoking chapters on: why social justice is inherent yet often invisible in engineering education and practice; engineering design for social justice; social justice in the engineering sciences; social justice in human...

  13. Mechanical Engineering | Classification | College of Engineering & Applied

    Science.gov (United States)

    Engineering Concentration on Ergonomics M.S. Program in Computer Science Interdisciplinary Concentration on Energy Doctoral Programs in Engineering Non-Degree Candidate Departments Biomedical Engineering Biomedical Engineering Industry Advisory Council Civil & Environmental Engineering Civil &

  14. Biomedical Engineering | Classification | College of Engineering & Applied

    Science.gov (United States)

    Engineering Concentration on Ergonomics M.S. Program in Computer Science Interdisciplinary Concentration on Energy Doctoral Programs in Engineering Non-Degree Candidate Departments Biomedical Engineering Biomedical Engineering Industry Advisory Council Civil & Environmental Engineering Civil &

  15. Electrical Engineering | Classification | College of Engineering & Applied

    Science.gov (United States)

    Engineering Concentration on Ergonomics M.S. Program in Computer Science Interdisciplinary Concentration on Energy Doctoral Programs in Engineering Non-Degree Candidate Departments Biomedical Engineering Biomedical Engineering Industry Advisory Council Civil & Environmental Engineering Civil &

  16. Materials Science & Engineering | Classification | College of Engineering &

    Science.gov (United States)

    Biomedical Engineering Concentration on Ergonomics M.S. Program in Computer Science Interdisciplinary Concentration on Energy Doctoral Programs in Engineering Non-Degree Candidate Departments Biomedical Engineering Biomedical Engineering Industry Advisory Council Civil & Environmental Engineering Civil &

  17. Engineering Encounters: Teaching Educators about Engineering

    Science.gov (United States)

    Tank, Kristina M.; Raman, D. Raj; Lamm, Monica H.; Sundararajan, Sriram; Estapa, Anne

    2017-01-01

    This column presents ideas and techniques to enhance science teaching. This month's issue describes preservice elementary teachers learning engineering principles from engineers. Few elementary teachers have experience with implementing engineering into the classroom. While engineering professional development opportunities for inservice teachers…

  18. An engineering context for software engineering

    OpenAIRE

    Riehle, Richard D.

    2008-01-01

    New engineering disciplines are emerging in the late Twentieth and early Twenty-first Century. One such emerging discipline is software engineering. The engineering community at large has long harbored a sense of skepticism about the validity of the term software engineering. During most of the fifty-plus years of software practice, that skepticism was probably justified. Professional education of software developers often fell short of the standard expected for conventional engineers; so...

  19. Engineering opportunities in nuclear engineering

    International Nuclear Information System (INIS)

    Walton, D.G.

    1980-01-01

    The pattern of education and training of Nuclear Engineers in the UK is outlined under the headings; degree courses for professional engineers, postgraduate courses, education of technician engineers. Universities which offer specific courses are stated and useful addresses listed. (UK)

  20. Humanitarian engineering in the engineering curriculum

    Science.gov (United States)

    Vandersteen, Jonathan Daniel James

    There are many opportunities to use engineering skills to improve the conditions for marginalized communities, but our current engineering education praxis does not instruct on how engineering can be a force for human development. In a time of great inequality and exploitation, the desire to work with the impoverished is prevalent, and it has been proposed to adjust the engineering curriculum to include a larger focus on human needs. This proposed curriculum philosophy is called humanitarian engineering. Professional engineers have played an important role in the modern history of power, wealth, economic development, war, and industrialization; they have also contributed to infrastructure, sanitation, and energy sources necessary to meet human need. Engineers are currently at an important point in time when they must look back on their history in order to be more clear about how to move forward. The changing role of the engineer in history puts into context the call for a more balanced, community-centred engineering curriculum. Qualitative, phenomenographic research was conducted in order to understand the need, opportunity, benefits, and limitations of a proposed humanitarian engineering curriculum. The potential role of the engineer in marginalized communities and details regarding what a humanitarian engineering program could look like were also investigated. Thirty-two semi-structured research interviews were conducted in Canada and Ghana in order to collect a pool of understanding before a phenomenographic analysis resulted in five distinct outcome spaces. The data suggests that an effective curriculum design will include teaching technical skills in conjunction with instructing about issues of social justice, social location, cultural awareness, root causes of marginalization, a broader understanding of technology, and unlearning many elements about the role of the engineer and the dominant economic/political ideology. Cross-cultural engineering development

  1. Quiet engine program flight engine design study

    Science.gov (United States)

    Klapproth, J. F.; Neitzel, R. E.; Seeley, C. T.

    1974-01-01

    The results are presented of a preliminary flight engine design study based on the Quiet Engine Program high-bypass, low-noise turbofan engines. Engine configurations, weight, noise characteristics, and performance over a range of flight conditions typical of a subsonic transport aircraft were considered. High and low tip speed engines in various acoustically treated nacelle configurations were included.

  2. 2016 Milwaukee Engineering Research Conference | College of Engineering &

    Science.gov (United States)

    Biomedical Engineering Concentration on Ergonomics M.S. Program in Computer Science Interdisciplinary Concentration on Energy Doctoral Programs in Engineering Non-Degree Candidate Departments Biomedical Engineering Biomedical Engineering Industry Advisory Council Civil & Environmental Engineering Civil &

  3. Hire a Milwaukee Engineer | College of Engineering & Applied Science

    Science.gov (United States)

    Electrical Engineering Instructional Laboratories Student Resources Industrial & Manufacturing Engineering Industrial & Manufacturing Engineering Academic Programs Industrial & Manufacturing Engineering Major Industrial & Manufacturing Engineering Minor Industrial & Manufacturing Engineering

  4. Cell lysis and superoxide dismutase activities of highly radioresistant bacteria

    Energy Technology Data Exchange (ETDEWEB)

    Yoshinaka, T; Yano, K; Yamaguchi, H [Tokyo Univ. (Japan). Faculty of Agriculture

    1976-01-01

    The highly radioresistant bacterium, Arthrobacter radiotolerans, has been isolated from the radioactive hot spring of Misasa, and it does not sporulate, it is Gram-positive, and its color is pink to red. This bacterium shows the highest resistance to gamma-ray among Gram-positive resistants, but the lytic enzyme capable of lysing the cells of strong radioresistants and the surface structure of the cells are little known except those about Micrococcus radiodurans. The cells of the M. radiodurans can be lysed by Achramobacter lyticus enzyme, and electron microscopic observation and chemical analysis revealed the mutilayered surface structure of the cells consisting of an inner membrane, a mucopeptide wall layer and a very outer layer. The superoxide dismutase (SOD) activity of aerobic and anaerobic bacteria was studied, and the relatively high SOD activity of the M. radiodurans was found. The SOD function acts against the threat posed by the reactive superoxide radical being generated biologically, photochemically and radiochemically in the presence of molecular oxygen. In this paper, it is reported that the lytic enzyme No.2 obtained from Cytophaga sp., containing N-acetyl-muramyl-L-alanine amidase, peptidase and endopeptidase, and showing broad lytic spectra, was able to lyse the cells of A. radiotolerans and four radioresistant micrococci, and the radioresistant bacteria showedrelatively high SOD activity except M. sp. 248. It is well known that superoxide anions are generated by aerobic irradiation, and are toxic to microbial cells.

  5. Cell lysis and superoxide dismutase activities of highly radioresistant bacteria

    International Nuclear Information System (INIS)

    Yoshinaka, Taeko; Yano, Keiji; Yamaguchi, Hikoyuki

    1976-01-01

    The highly radioresistant bacterium, Arthrobacter radiotolerans, has been isolated from the radioactive hot spring of Misasa, and it does not sporulate, it is Gram-positive, and its color is pink to red. This bacterium shows the highest resistance to gamma-ray among Gram-positive resistants, but the lytic enzyme capable of lysing the cells of strong radioresistants and the surface structure of the cells are little known except those about Micrococcus radiodurans. The cells of the M. radiodurans can be lysed by Achramobacter lyticus enzyme, and electron microscopic observation and chemical analysis revealed the mutilayered surface structure of the cells consisting of an inner membrane, a mucopeptide wall layer and a very outer layer. The superoxide dismutase (SOD) activity of aerobic and anaerobic bacteria was studied, and the relatively high SOD activity of the M. radiodurans was found. The SOD function acts against the threat posed by the reactive superoxide radical being generated biologically, photochemically and radiochemically in the presence of molecular oxygen. In this paper, it is reported that the lytic enzyme No.2 obtained from Cytophaga sp., containing N-acetyl-muramyl-L-alanine amidase, peptidase and endopeptidase, and showing broad lytic spectra, was able to lyse the cells of A. radiotolerans and four radioresistant micrococci, and the radioresistant bacteria showed relatively high SOD activity except M. sp. 248. It is well known that superoxide anions are generated by aerobic irradiation, and are toxic to microbial cells. (Kako, I.)

  6. Engineer Ethics

    International Nuclear Information System (INIS)

    Lee, Dae Sik; Kim, Yeong Pil; Kim, Yeong Jin

    2003-03-01

    This book tells of engineer ethics such as basic understanding of engineer ethics with history of engineering as a occupation, definition of engineering and specialized job and engineering, engineer ethics as professional ethics, general principles of ethics and its limitation, ethical theory and application, technique to solve the ethical problems, responsibility, safety and danger, information engineer ethics, biotechnological ethics like artificial insemination, life reproduction, gene therapy and environmental ethics.

  7. 78 FR 5710 - Airworthiness Directives; Engine Alliance Turbofan Engines

    Science.gov (United States)

    2013-01-28

    ... Airworthiness Directives; Engine Alliance Turbofan Engines AGENCY: Federal Aviation Administration (FAA), DOT... all Engine Alliance GP7270 and GP7277 turbofan engines. This AD requires initial and repetitive...) Applicability This AD applies to all Engine Alliance GP7270 and GP7277 turbofan engines with a high-pressure...

  8. Staged combustion with piston engine and turbine engine supercharger

    Science.gov (United States)

    Fischer, Larry E [Los Gatos, CA; Anderson, Brian L [Lodi, CA; O'Brien, Kevin C [San Ramon, CA

    2011-11-01

    A combustion engine method and system provides increased fuel efficiency and reduces polluting exhaust emissions by burning fuel in a two-stage combustion system. Fuel is combusted in a piston engine in a first stage producing piston engine exhaust gases. Fuel contained in the piston engine exhaust gases is combusted in a second stage turbine engine. Turbine engine exhaust gases are used to supercharge the piston engine.

  9. Environmental Engineering in Mining Engineering Education

    Science.gov (United States)

    Mahamud-Lopez, Manuel Maria; Menendez-Aguado, Juan Maria

    2005-01-01

    In this paper, the current profile of the environmental engineer and the programming of the subject "Environmental Engineering and Technology" corresponding to the studies of Mining Engineering at the University of Oviedo in Spain, is discussed. Professional profile, student knowledge prior to and following instruction as well as…

  10. Engineering Encounters: Blasting off with Engineering

    Science.gov (United States)

    Dare, Emily A.; Childs, Gregory T.; Cannaday, E. Ashley; Roehrig, Gillian H

    2014-01-01

    What better way to engage young students in physical science concepts than to have them engineer flying toy rockets? The integration of engineering into science classrooms is advocated by the "Next Generation Science Standards" (NGSS) and researchers alike (Brophy et al. 2008), as engineering provides: (1) A "real-world…

  11. Perturbing engine performance measurements to determine optimal engine control settings

    Science.gov (United States)

    Jiang, Li; Lee, Donghoon; Yilmaz, Hakan; Stefanopoulou, Anna

    2014-12-30

    Methods and systems for optimizing a performance of a vehicle engine are provided. The method includes determining an initial value for a first engine control parameter based on one or more detected operating conditions of the vehicle engine, determining a value of an engine performance variable, and artificially perturbing the determined value of the engine performance variable. The initial value for the first engine control parameter is then adjusted based on the perturbed engine performance variable causing the engine performance variable to approach a target engine performance variable. Operation of the vehicle engine is controlled based on the adjusted initial value for the first engine control parameter. These acts are repeated until the engine performance variable approaches the target engine performance variable.

  12. Genome scale engineering techniques for metabolic engineering.

    Science.gov (United States)

    Liu, Rongming; Bassalo, Marcelo C; Zeitoun, Ramsey I; Gill, Ryan T

    2015-11-01

    Metabolic engineering has expanded from a focus on designs requiring a small number of genetic modifications to increasingly complex designs driven by advances in genome-scale engineering technologies. Metabolic engineering has been generally defined by the use of iterative cycles of rational genome modifications, strain analysis and characterization, and a synthesis step that fuels additional hypothesis generation. This cycle mirrors the Design-Build-Test-Learn cycle followed throughout various engineering fields that has recently become a defining aspect of synthetic biology. This review will attempt to summarize recent genome-scale design, build, test, and learn technologies and relate their use to a range of metabolic engineering applications. Copyright © 2015 International Metabolic Engineering Society. Published by Elsevier Inc. All rights reserved.

  13. Problem Decomposition and Recomposition in Engineering Design: A Comparison of Design Behavior between Professional Engineers, Engineering Seniors, and Engineering Freshmen

    Science.gov (United States)

    Song, Ting; Becker, Kurt; Gero, John; DeBerard, Scott; DeBerard, Oenardi; Reeve, Edward

    2016-01-01

    The authors investigated the differences in using problem decomposition and problem recomposition between dyads of engineering experts, engineering seniors, and engineering freshmen. Participants worked in dyads to complete an engineering design challenge within 1 hour. The entire design process was video and audio recorded. After the design…

  14. Activist engineering: changing engineering practice by deploying praxis.

    Science.gov (United States)

    Karwat, Darshan M A; Eagle, Walter E; Wooldridge, Margaret S; Princen, Thomas E

    2015-02-01

    In this paper, we reflect on current notions of engineering practice by examining some of the motives for engineered solutions to the problem of climate change. We draw on fields such as science and technology studies, the philosophy of technology, and environmental ethics to highlight how dominant notions of apoliticism and ahistoricity are ingrained in contemporary engineering practice. We argue that a solely technological response to climate change does not question the social, political, and cultural tenet of infinite material growth, one of the root causes of climate change. In response to the contemporary engineering practice, we define an activist engineer as someone who not only can provide specific engineered solutions, but who also steps back from their work and tackles the question, What is the real problem and does this problem "require" an engineering intervention? Solving complex problems like climate change requires radical cultural change, and a significant obstacle is educating engineers about how to conceive of and create "authentic alternatives," that is, solutions that differ from the paradigm of "technologically improving" our way out of problems. As a means to realize radically new solutions, we investigate how engineers might (re)deploy the concept of praxis, which raises awareness in engineers of the inherent politics of technological design. Praxis empowers engineers with a more comprehensive understanding of problems, and thus transforms technologies, when appropriate, into more socially just and ecologically sensitive interventions. Most importantly, praxis also raises a radical alternative rarely considered-not "engineering a solution." Activist engineering offers a contrasting method to contemporary engineering practice and leads toward social justice and ecological protection through problem solving by asking not, How will we technologize our way out of the problems we face? but instead, What really needs to be done?

  15. Chemical Engineering Students: A Distinct Group among Engineers

    Science.gov (United States)

    Godwin, Allison; Potvin, Geoff

    2013-01-01

    This paper explores differences between chemical engineering students and students of other engineering disciplines, as identified by their intended college major. The data used in this analysis was taken from the nationally representative Sustainability and Gender in Engineering (SaGE) survey. Chemical engineering students differ significantly…

  16. Site systems engineering: Systems engineering management plan

    Energy Technology Data Exchange (ETDEWEB)

    Grygiel, M.L. [Westinghouse Hanford Co., Richland, WA (United States)

    1996-05-03

    The Site Systems Engineering Management Plan (SEMP) is the Westinghouse Hanford Company (WHC) implementation document for the Hanford Site Systems Engineering Policy, (RLPD 430.1) and Systems Engineering Criteria Document and Implementing Directive, (RLID 430.1). These documents define the US Department of Energy (DOE), Richland Operations Office (RL) processes and products to be used at Hanford to implement the systems engineering process at the site level. This SEMP describes the products being provided by the site systems engineering activity in fiscal year (FY) 1996 and the associated schedule. It also includes the procedural approach being taken by the site level systems engineering activity in the development of these products and the intended uses for the products in the integrated planning process in response to the DOE policy and implementing directives. The scope of the systems engineering process is to define a set of activities and products to be used at the site level during FY 1996 or until the successful Project Hanford Management Contractor (PHMC) is onsite as a result of contract award from Request For Proposal DE-RP06-96RL13200. Following installation of the new contractor, a long-term set of systems engineering procedures and products will be defined for management of the Hanford Project. The extent to which each project applies the systems engineering process and the specific tools used are determined by the project`s management.

  17. Engineering Encounters: Reverse Engineering

    Science.gov (United States)

    McGowan, Veronica Cassone; Ventura, Marcia; Bell, Philip

    2017-01-01

    This column presents ideas and techniques to enhance your science teaching. This month's issue shares information on how students' everyday experiences can support science learning through engineering design. In this article, the authors outline a reverse-engineering model of instruction and describe one example of how it looked in our fifth-grade…

  18. High School Teachers' Conceptions of Engineers and Engineering

    Science.gov (United States)

    Hoh, Yin Kiong

    2012-01-01

    This paper describes a workshop activity the author has carried out with 80 high school science teachers to enable them to overcome their stereotypical perceptions of engineers and engineering. The activity introduced them to the biographies of prominent women in engineering, and raised their awareness of these female engineers' contributions to…

  19. Governing Engineering

    DEFF Research Database (Denmark)

    Buch, Anders

    2012-01-01

    Most people agree that our world face daunting problems and, correctly or not, technological solutions are seen as an integral part of an overall solution. But what exactly are the problems and how does the engineering ‘mind set’ frame these problems? This chapter sets out to unravel dominant...... perspectives in challenge per-ception in engineering in the US and Denmark. Challenge perception and response strategies are closely linked through discursive practices. Challenge perceptions within the engineering community and the surrounding society are thus critical for the shaping of engineering education...... and the engineering profession. Through an analysis of influential reports and position papers on engineering and engineering education the chapter sets out to identify how engineering is problematized and eventually governed. Drawing on insights from governmentality studies the chapter strives to elicit the bodies...

  20. Governing Engineering

    DEFF Research Database (Denmark)

    Buch, Anders

    2011-01-01

    Abstract: Most people agree that our world faces daunting problems and, correctly or not, technological solutions are seen as an integral part of an overall solution. But what exactly are the problems and how does the engineering ‘mind set’ frame these problems? This chapter sets out to unravel...... dominant perspectives in challenge perception in engineering in the US and Denmark. Challenge perception and response strategies are closely linked through discursive practices. Challenge perceptions within the engineering community and the surrounding society are thus critical for the shaping...... of engineering education and the engineering profession. Through an analysis of influential reports and position papers on engineering and engineering education the chapter sets out to identify how engineering is problematized and eventually governed. Drawing on insights from governmentality studies the chapter...

  1. Modular Engineering Concept at Novo Nordisk Engineering

    DEFF Research Database (Denmark)

    Moelgaard, Gert; Miller, Thomas Dedenroth

    1997-01-01

    This report describes the concept of a new engineering method at Novo Nordisk Engineering: Modular Engineering (ME). Three tools are designed to support project phases with different levels of detailing and abstraction. ME supports a standard, cross-functional breakdown of projects that facilitates...

  2. Mechanical engineering

    CERN Document Server

    Darbyshire, Alan

    2010-01-01

    Alan Darbyshire's best-selling text book provides five-star high quality content to a potential audience of 13,000 engineering students. It explains the most popular specialist units of the Mechanical Engineering, Manufacturing Engineering and Operations & Maintenance Engineering pathways of the new 2010 BTEC National Engineering syllabus. This challenging textbook also features contributions from specialist lecturers, ensuring that no stone is left unturned.

  3. A broadcast engineering tutorial for non-engineers

    CERN Document Server

    Pizzi, Skip

    2014-01-01

    A Broadcast Engineering Tutorial for Non-Engineers is the leading publication on the basics of broadcast technology. Whether you are new to the industry or do not have an engineering background, this book will give you a comprehensive primer of television, radio, and digital media relating to broadcast-it is your guide to understanding the technical world of radio and television broadcast engineering. It covers all the important topics such as DTV, IBOC, HD, standards, video servers, editing, electronic newsrooms, and more.

  4. Engine systems and methods of operating an engine

    Science.gov (United States)

    Scotto, Mark Vincent

    2015-08-25

    One embodiment of the present invention is a unique method for operating an engine. Another embodiment is a unique engine system. Other embodiments include apparatuses, systems, devices, hardware, methods, and combinations for engines and engine systems. Further embodiments, forms, features, aspects, benefits, and advantages of the present application will become apparent from the description and figures provided herewith.

  5. Engine systems and methods of operating an engine

    Energy Technology Data Exchange (ETDEWEB)

    Scotto, Mark Vincent

    2018-01-23

    One embodiment of the present invention is a unique method for operating an engine. Another embodiment is a unique engine system. Other embodiments include apparatuses, systems, devices, hardware, methods, and combinations for engines and engine systems. Further embodiments, forms, features, aspects, benefits, and advantages of the present application will become apparent from the description and figures provided herewith.

  6. Engineering Institute

    Science.gov (United States)

    Projects Past Projects Publications NSEC » Engineering Institute Engineering Institute Multidisciplinary engineering research that integrates advanced modeling and simulations, novel sensing systems and new home of Engineering Institute Contact Institute Director Charles Farrar (505) 665-0860 Email UCSD EI

  7. Biomedical engineering education through global engineering teams.

    Science.gov (United States)

    Scheffer, C; Blanckenberg, M; Garth-Davis, B; Eisenberg, M

    2012-01-01

    Most industrial projects require a team of engineers from a variety of disciplines. The team members are often culturally diverse and geographically dispersed. Many students do not acquire sufficient skills from typical university courses to function efficiently in such an environment. The Global Engineering Teams (GET) programme was designed to prepare students such a scenario in industry. This paper discusses five biomedical engineering themed projects completed by GET students. The benefits and success of the programme in educating students in the field of biomedical engineering are discussed.

  8. Linguistic Engineering and Linguistic of Engineering: Adaptation of Linguistic Paradigm for Circumstance of Engineering Epoch

    OpenAIRE

    Natalya Halina

    2014-01-01

    The article is devoted to the problems of linguistic knowledge in the Engineering Epoch. Engineering Epoch is the time of adaptation to the information flows by knowledge management, The system of adaptation mechanisms is connected with linguistic and linguistic technologies, forming in new linguistic patterns Linguistic Engineering and Linguistic of Engineering.

  9. Engineering Bereitschaft as an enabler for Concurrent Engineering

    DEFF Research Database (Denmark)

    Christiansen, Kåre; Vesterager, Johan

    1999-01-01

    Industrial companies observe a general trend towards more customised products and shorter product life cycles. Furthermore, the market demands shorter lead-time and high-quality products at a competitive price. Concurrent Engineering address these challenges. Product modelling is a key aspect...... of the Concurrent Engineering literature. One problem with the product modelling literature is that it tends to assume that product development is revolutionary. Very often product development is evolutionary and it means that product modelling should have a major emphasis on reuse. In this paper it is suggested...... that industrial companies should develop an engineering development Bereitschaft (preparatory engineering knowledge) as an approach to Concurrent Engineering and product modelling. To develop such an engineering development Bereitschaft, a company must develop company generic product models.This paper...

  10. Building inclusive engineering identities: implications for changing engineering culture

    Science.gov (United States)

    Atadero, Rebecca A.; Paguyo, Christina H.; Rambo-Hernandez, Karen E.; Henderson, Heather L.

    2018-05-01

    Ongoing efforts to broaden the participation of women and people of colour in engineering degree programmes and careers have had limited success. This paper describes a different approach to broadening participation that seeks to work with all students and develop inclusive engineering identities. Researchers worked with the instructors of two first-year engineering courses to integrate curriculum activities designed to promote the formation of engineering identities and build an appreciation for how diversity and inclusion strengthen engineering practice. Multilevel modelling results indicated positive effects of the intervention on appreciation for diversity but no effects on engineering identity, and qualitative results indicated students learned the most about diversity not through one of the intervention activities, but through team projects in the courses. We also describe lessons learned in how to teach engineering students about diversity in ways that are relevant to engineering.

  11. Engineering Change Management Method Framework in Mechanical Engineering

    Science.gov (United States)

    Stekolschik, Alexander

    2016-11-01

    Engineering changes make an impact on different process chains in and outside the company, and lead to most error costs and time shifts. In fact, 30 to 50 per cent of development costs result from technical changes. Controlling engineering change processes can help us to avoid errors and risks, and contribute to cost optimization and a shorter time to market. This paper presents a method framework for controlling engineering changes at mechanical engineering companies. The developed classification of engineering changes and accordingly process requirements build the basis for the method framework. The developed method framework comprises two main areas: special data objects managed in different engineering IT tools and process framework. Objects from both areas are building blocks that can be selected to the overall business process based on the engineering process type and change classification. The process framework contains steps for the creation of change objects (both for overall change and for parts), change implementation, and release. Companies can select singleprocess building blocks from the framework, depending on the product development process and change impact. The developed change framework has been implemented at a division (10,000 employees) of a big German mechanical engineering company.

  12. 40 CFR 1045.140 - What is my engine's maximum engine power?

    Science.gov (United States)

    2010-07-01

    ...) Maximum engine power for an engine family is generally the weighted average value of maximum engine power... engine family's maximum engine power apply in the following circumstances: (1) For outboard or personal... value for maximum engine power from all the different configurations within the engine family to...

  13. Handbook of Software Engineering and Knowledge Engineering

    CERN Document Server

    2001-01-01

    This is the first handbook to cover comprehensively both software engineering and knowledge engineering - two important fields that have become interwoven in recent years. Over 60 international experts have contributed to the book. Each chapter has been written in such a way that a practitioner of software engineering and knowledge engineering can easily understand and obtain useful information. Each chapter covers one topic and can be read independently of other chapters, providing both a general survey of the topic and an in-depth exposition of the state of the art.

  14. Architectural Engineers

    DEFF Research Database (Denmark)

    Petersen, Rikke Premer

    engineering is addresses from two perspectives – as an educational response and an occupational constellation. Architecture and engineering are two of the traditional design professions and they frequently meet in the occupational setting, but at educational institutions they remain largely estranged....... The paper builds on a multi-sited study of an architectural engineering program at the Technical University of Denmark and an architectural engineering team within an international engineering consultancy based on Denmark. They are both responding to new tendencies within the building industry where...... the role of engineers and architects increasingly overlap during the design process, but their approaches reflect different perceptions of the consequences. The paper discusses some of the challenges that design education, not only within engineering, is facing today: young designers must be equipped...

  15. Ideas of holistic engineering meet engineering work practices

    DEFF Research Database (Denmark)

    Buch, Anders

    2016-01-01

    This article critically reflects on the viability of the idea that reforming engineering education will result in more holistic engineering work practices. Drawing on an empirical study, the article aims to demonstrate that in order to change existing engineering work practices, it might...... be necessary to change engineers’ knowledge and skills; however, such changes are far from sufficient. Conditions and circumstances external to practitioners’ knowledge and skills are crucial if engineering work is to become more holistic. To illustrate this point, the article outlines an empirical study...... of a small team of professionals who engage in holistic engineering work practices in an engineering consultancy company. The work practices are investigated using a philosophical empirical method that inquires into the doings, sayings, and relatings of the practitioners. The study describes the practice...

  16. Tissue engineering

    CERN Document Server

    Fisher, John P; Bronzino, Joseph D

    2007-01-01

    Increasingly viewed as the future of medicine, the field of tissue engineering is still in its infancy. As evidenced in both the scientific and popular press, there exists considerable excitement surrounding the strategy of regenerative medicine. To achieve its highest potential, a series of technological advances must be made. Putting the numerous breakthroughs made in this field into a broad context, Tissue Engineering disseminates current thinking on the development of engineered tissues. Divided into three sections, the book covers the fundamentals of tissue engineering, enabling technologies, and tissue engineering applications. It examines the properties of stem cells, primary cells, growth factors, and extracellular matrix as well as their impact on the development of tissue engineered devices. Contributions focus on those strategies typically incorporated into tissue engineered devices or utilized in their development, including scaffolds, nanocomposites, bioreactors, drug delivery systems, and gene t...

  17. Start Your Engines: Surfing with Search Engines for Kids.

    Science.gov (United States)

    Byerly, Greg; Brodie, Carolyn S.

    1999-01-01

    Suggests that to be an effective educator and user of the Web it is essential to know the basics about search engines. Presents tips for using search engines. Describes several search engines for children and young adults, as well as some general filtered search engines for children. (AEF)

  18. Engineers and Bildung

    DEFF Research Database (Denmark)

    Henriksen, Lars Bo

    2006-01-01

    and Bildung. In this chapter, this relation in investigated. In the first part, I present three engineers and their careers. In the second part, the concept of Bildung is analyzed, and in the third part, it is the conceptual relation between Bildung, engineers, and engineering work that is of concern.......What is an engineer? Or maybe better: how are engineers, and how are they “gebilded” in order to be able to be called engineers? In order to shed some light on this question we could ask: How is the relation between engineering and the making of an engineer, or the relation between engineering...

  19. 78 FR 35747 - Airworthiness Directives; Engine Alliance Turbofan Engines

    Science.gov (United States)

    2013-06-14

    ... Airworthiness Directives; Engine Alliance Turbofan Engines AGENCY: Federal Aviation Administration (FAA), DOT... Alliance GP7270 and GP7277 turbofan engines. This AD was prompted by damage to the high-pressure compressor... Alliance GP7270 and GP7277 turbofan engines with a high-pressure compressor (HPC) stage 6 disk, part number...

  20. Internet Search Engines

    OpenAIRE

    Fatmaa El Zahraa Mohamed Abdou

    2004-01-01

    A general study about the internet search engines, the study deals main 7 points; the differance between search engines and search directories, components of search engines, the percentage of sites covered by search engines, cataloging of sites, the needed time for sites appearance in search engines, search capabilities, and types of search engines.

  1. Computational engineering

    CERN Document Server

    2014-01-01

    The book presents state-of-the-art works in computational engineering. Focus is on mathematical modeling, numerical simulation, experimental validation and visualization in engineering sciences. In particular, the following topics are presented: constitutive models and their implementation into finite element codes, numerical models in nonlinear elasto-dynamics including seismic excitations, multiphase models in structural engineering and multiscale models of materials systems, sensitivity and reliability analysis of engineering structures, the application of scientific computing in urban water management and hydraulic engineering, and the application of genetic algorithms for the registration of laser scanner point clouds.

  2. Dicty_cDB: Contig-U11181-1 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available id:none) Pyrobaculum aerophilum str. IM2,... 94 2e-17 AM944373_1( AM944373 |pid:n...one) Propionibacterium freudenreichii s... 93 3e-17 CP001114_2205( CP001114 |pid:none) Deinococcus deserti V

  3. Characterization of Thermostable Cellulases Produced by Bacillus and Geobacillus Strains

    Science.gov (United States)

    Bacterial community composition of thermophilic (60 deg C) mixed cellulose-enrichment cultures was examined by constructing a 16S rDNA clone library which demonstrated major lineages affiliated to Actinobacteria, Bacteroidetes, Chloroflexi, Deinococcus-Thermus, Firmicutes, and Proteobacteria. A tot...

  4. Combustion Temperature Effect of Diesel Engine Convert to Compressed Natural Gas Engine

    OpenAIRE

    Semin; Abdul R. Ismail; Rosli A. Bakar

    2009-01-01

    Effect of combustion temperature in the engine cylinder of diesel engine convert to Compressed Natural Gas (CNG) engine was presents in this study. The objective of this study was to investigate the engine cylinder combustion temperature effect of diesel engine convert to CNG engine on variation engine speed. Problem statement: The hypothesis was that the lower performance of CNG engine was caused by the effect of lower in engine cylinder temperature. Are the CNG engine is lower cylinder temp...

  5. Choosing nuclear engineering: A survey of nuclear engineering undergraduates

    International Nuclear Information System (INIS)

    Shillenn, J.K.; Klevans, E.H.

    1988-01-01

    Maintaining a reliable pool of qualified nuclear engineering graduates depends on the ability of nuclear engineering undergraduate programs to recruit students. With the prospect of declining enrollments in nuclear engineering it is important for nuclear engineering programs to know what factors influence students to choose nuclear engineering as an undergraduate major and why they choose a particular undergraduate program. This type of information can be very important to nuclear engineering programs that develop recruiting strategies. To provide some insight into this area, a questionnaire was designed and given to undergraduate nuclear engineering students at Pennsylvania State University. The purpose of the survey was to provide information on the reasons that students picked nuclear engineering as a career and chose to attend Penn State. The questionnaire was given to 27 students in their junior year during the spring semester of 1987 and again to 35 junior students during the spring semester of 1988. There was little difference except as noted between the two groups on their responses to the questionnaire. A partial listing of the survey results is provided

  6. Invisible Engineers

    Science.gov (United States)

    Ohashi, Hideo

    Questionnaire to ask “mention three names of scientists you know” and “three names of engineers you know” was conducted and the answers from 140 adults were analyzed. The results indicated that the image of scientists is represented by Nobel laureates and that of engineers by great inventors like Thomas Edison and industry founders like Soichiro Honda. In order to reveal the image of engineers among young generation, questionnaire was conducted for pupils in middle and high schools. Answers from 1,230 pupils were analyzed and 226 names mentioned as engineers were classified. White votes reached 60%. Engineers who are neither big inventors nor company founders collected less than 1% of named votes. Engineers are astonishingly invisible from young generation. Countermeasures are proposed.

  7. Global engineering

    International Nuclear Information System (INIS)

    Plass, L.

    2001-01-01

    This article considers the challenges posed by the declining orders in the plant engineering and contracting business in Germany, the need to remain competitive, and essential preconditions for mastering the challenge. The change in engineering approach is illustrated by the building of a methanol plant in Argentina by Lurgi with the basic engineering completed in Frankfurt with involvement of key personnel from Poland, completely engineered subsystems from a Brazilian subsupplier, and detailed engineering work in Frankfurt. The production of methanol from natural gas using the LurgiMega/Methanol process is used as a typical example of the industrial plant construction sector. The prerequisites for successful global engineering are listed, and error costs in plant construction, possible savings, and process intensification are discussed

  8. Transforming Systems Engineering through Model Centric Engineering

    Science.gov (United States)

    2017-08-08

    Contract No. HQ0034-13-D-0004 Report No. SERC-2017-TR-110 Date: August 8, 2017 Transforming Systems Engineering through Model-Centric... Engineering Technical Report SERC-2017-TR-110 Update: August 8, 2017 Principal Investigator: Mark Blackburn, Stevens Institute of Technology Co...Evangelista Sponsor: U.S. Army Armament Research, Development and Engineering Center (ARDEC), Office of the Deputy Assistant Secretary of Defense for

  9. ABET [Accreditation Board for Engineering and Technology] accreditation for engineering technology

    International Nuclear Information System (INIS)

    Foulke, L.R.

    1989-01-01

    Engineering technology is that part of the technological field that requires the application of scientific and engineering knowledge and methods combined with technical skills in support of engineering activities. It lies in the occupational spectrum between the craftsman and the engineer at the end of the spectrum closest to the engineer. The term engineering technician is applied to the graduates of associate degree programs. Graduates of baccalaureate programs are called engineering technologists. The content of a 4-yr engineering technology program treats the same subject areas as does an engineering program but with more emphasis on application, use of established design concepts, and the laboratory experience rather than on science, conceptual design, and new development. The mathematics content of accreditable baccalaureate programs must contain at least 12 semester-hour credits of mathematics including the study of calculus. Engineering managers should take a hard look at what is really needed in the education of that majority of a personnel who do not work as design and development engineers. Graduates of engineering technology programs may be better qualified than those of some engineering programs for the majority of jobs in our industry today

  10. Contemporary engineering economics

    CERN Document Server

    Park, Chan S

    2011-01-01

    Contemporary Engineering Economics, 5/e, is intended for undergraduate engineering students taking introductory engineering economics while appealing to the full range of engineering disciplines for which this course is often required: industrial, civil, mechanical, electrical, computer, aerospace, chemical, and manufacturing engineering, as well as engineering technology. This edition has been thoroughly revised and updated while continuing to adopt a contemporary approach to the subject, and teaching, of engineering economics. This text aims not only to build a sound and comprehensive coverage of engineering economics, but also to address key educational challenges, such as student difficulty in developing the analytical skills required to make informed financial decisions.

  11. Solar engine system

    International Nuclear Information System (INIS)

    Tan, K.K.; Bahrom Sanugi; Chen, L.C.; Chong, K.K.; Jasmy Yunus; Kannan, K.S.; Lim, B.H.; Noriah Bidin; Omar Aliman; Sahar Salehan; Sheikh Ab Rezan Sheikh A H; Tam, C.M.; Chen, Y.T.

    2001-01-01

    This paper reports the revolutionary solar engine system in Universiti Teknologi Malaysia (UTM). The solar engine is a single cylinder stirling engine driven by solar thermal energy. A first prototype solar engine has been built and demonstrated. A new-concept non-imaging focusing heliostat and a recently invented optical receiver are used in the demonstration. Second generation of prototype solar engine is described briefly. In this paper, the solar engine system development is reported. Measurement for the first prototype engine speed, temperature and specifications are presented. The benefits and potential applications for the future solar engine system, especially for the electricity generating aspect are discussed. (Author)

  12. Advanced Natural Gas Reciprocating Engine(s)

    Energy Technology Data Exchange (ETDEWEB)

    Kwok, Doris; Boucher, Cheryl

    2009-09-30

    Energy independence and fuel savings are hallmarks of the nation’s energy strategy. The advancement of natural gas reciprocating engine power generation technology is critical to the nation’s future. A new engine platform that meets the efficiency, emissions, fuel flexibility, cost and reliability/maintainability targets will enable American manufacturers to have highly competitive products that provide substantial environmental and economic benefits in the US and in international markets. Along with Cummins and Waukesha, Caterpillar participated in a multiyear cooperative agreement with the Department of Energy to create a 50% efficiency natural gas powered reciprocating engine system with a 95% reduction in NOx emissions by the year 2013. This platform developed under this agreement will be a significant contributor to the US energy strategy and will enable gas engine technology to remain a highly competitive choice, meeting customer cost of electricity targets, and regulatory environmental standard. Engine development under the Advanced Reciprocating Engine System (ARES) program was divided into phases, with the ultimate goal being approached in a series of incremental steps. This incremental approach would promote the commercialization of ARES technologies as soon as they emerged from development and would provide a technical and commercial foundation of later-developing technologies. Demonstrations of the Phase I and Phase II technology were completed in 2004 and 2008, respectively. Program tasks in Phase III included component and system development and testing from 2009-2012. Two advanced ignition technology evaluations were investigated under the ARES program: laser ignition and distributed ignition (DIGN). In collaboration with Colorado State University (CSU), a laser ignition system was developed to provide ignition at lean burn and high boost conditions. Much work has been performed in Caterpillar’s DIGN program under the ARES program. This work

  13. Mechanical Engineering Practice – using a simple Stirling engine as case

    DEFF Research Database (Denmark)

    Meyer, Knud Erik

    2011-01-01

    The first technical course that students in mechanical engineering take at the Technical University of Denmark is called “Mechanical Engineering Practice”. We have used a simple Stirling engine as a design-implement project. Students were asked to design and build a heat engine using materials....... The Stirling engine worked well in the drawing assignments. The Stirling engine also served as illustration of coming courses in mechanical engineering. The resulting engines had large variations in their design and most groups succeeded in building a functioning engine. However, achieved efficiencies were...... obtained by their own means and were competing on achieving the highest efficiency. We added an extra dimension to the project by making detailed measurements of the pressure variation to check simple thermodynamic models of the engine. The course had integrated lessons in sketching and technical drawing...

  14. Engineering graphic modelling a workbook for design engineers

    CERN Document Server

    Tjalve, E; Frackmann Schmidt, F

    2013-01-01

    Engineering Graphic Modelling: A Practical Guide to Drawing and Design covers how engineering drawing relates to the design activity. The book describes modeled properties, such as the function, structure, form, material, dimension, and surface, as well as the coordinates, symbols, and types of projection of the drawing code. The text provides drawing techniques, such as freehand sketching, bold freehand drawing, drawing with a straightedge, a draughting machine or a plotter, and use of templates, and then describes the types of drawing. Graphic designers, design engineers, mechanical engine

  15. Systems engineering and integration as a foundation for mission engineering

    OpenAIRE

    Beam, David F.

    2015-01-01

    Approved for public release; distribution is unlimited This paper investigates the emerging term mission engineering through the framework of systems engineering and systems integration. Systems engineering concepts, processes, and methodologies are extrapolated for use in conjunction with a systems integration, life-cycle based framework to effect mission engineering. The specific systems engineering concepts of measures of effectiveness, performance and suitability are recommended as fou...

  16. Transforming Systems Engineering through Model-Centric Engineering

    Science.gov (United States)

    2018-02-28

    Contract No. HQ0034-13-D-0004 Research Tasks: 48, 118, 141, 157, 170 Report No. SERC-2018-TR-103 Transforming Systems Engineering through...Model-Centric Engineering Technical Report SERC-2018-TR-103 February 28, 2018 Principal Investigator Dr. Mark Blackburn, Stevens Institute of...Systems Engineering Research Center This material is based upon work supported, in whole or in part, by the U.S. Department of Defense through the

  17. 40 CFR 91.115 - Certification procedure-determining engine power and engine families.

    Science.gov (United States)

    2010-07-01

    ... engine power and engine families. 91.115 Section 91.115 Protection of Environment ENVIRONMENTAL... engine power and engine families. (a) Engine power must be calculated using SAE J1228. This procedure has... engine families as specified by paragraph (c) of this section, comprised of engines expected to have...

  18. Magical Engineering Plastic

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Gwang Ung

    1988-01-15

    This book introduces engineering plastic about advantage of engineering plastic, plastic material from processing method, plastic shock, plastic until now, background of making of engineering plastic, wonderful engineering plastic science such as a high molecule and molecule, classification of high molecule, difference between metal and high molecule, heat and high molecule materials, and property of surface, engineering plastic of dream like from linseed oil to aramid, small dictionary of engineering plastic.

  19. Magical Engineering Plastic

    International Nuclear Information System (INIS)

    Kim, Gwang Ung

    1988-01-01

    This book introduces engineering plastic about advantage of engineering plastic, plastic material from processing method, plastic shock, plastic until now, background of making of engineering plastic, wonderful engineering plastic science such as a high molecule and molecule, classification of high molecule, difference between metal and high molecule, heat and high molecule materials, and property of surface, engineering plastic of dream like from linseed oil to aramid, small dictionary of engineering plastic.

  20. Engineering flesh : towards professional responsibility for 'lived bodies' in tissue engineering

    NARCIS (Netherlands)

    Derksen, M.H.G.

    2008-01-01

    Engineering Flesh. Towards professional responsibility for ‘lived bodies’ in Tissue Engineering This study analyses the work of biomedical engineers as normative work that affects people’s daily lives as bodies. In biomedical engineering, engineers study bodies as machine-like objects and develop

  1. Teaching Engineering Practices

    Science.gov (United States)

    Cunningham, Christine M.; Carlsen, William S.

    2014-03-01

    Engineering is featured prominently in the Next Generation Science Standards (NGSS) and related reform documents, but how its nature and methods are described is problematic. This paper is a systematic review and critique of that representation, and proposes that the disciplinary core ideas of engineering (as described in the NGSS) can be disregarded safely if the practices of engineering are better articulated and modeled through student engagement in engineering projects. A clearer distinction between science and engineering practices is outlined, and prior research is described that suggests that precollege engineering design can strengthen children's understandings about scientific concepts. However, a piecemeal approach to teaching engineering practices is unlikely to result in students understanding engineering as a discipline. The implications for science teacher education are supplemented with lessons learned from a number of engineering education professional development projects.

  2. A simple method of calculating Stirling engines for engine design optimization

    Science.gov (United States)

    Martini, W. R.

    1978-01-01

    A calculation method is presented for a rhombic drive Stirling engine with a tubular heater and cooler and a screen type regenerator. Generally the equations presented describe power generation and consumption and heat losses. It is the simplest type of analysis that takes into account the conflicting requirements inherent in Stirling engine design. The method itemizes the power and heat losses for intelligent engine optimization. The results of engine analysis of the GPU-3 Stirling engine are compared with more complicated engine analysis and with engine measurements.

  3. Cycle Engine Modelling Of Spark Ignition Engine Processes during Wide-Open Throttle (WOT) Engine Operation Running By Gasoline Fuel

    International Nuclear Information System (INIS)

    Rahim, M F Abdul; Rahman, M M; Bakar, R A

    2012-01-01

    One-dimensional engine model is developed to simulate spark ignition engine processes in a 4-stroke, 4 cylinders gasoline engine. Physically, the baseline engine is inline cylinder engine with 3-valves per cylinder. Currently, the engine's mixture is formed by external mixture formation using piston-type carburettor. The model of the engine is based on one-dimensional equation of the gas exchange process, isentropic compression and expansion, progressive engine combustion process, and accounting for the heat transfer and frictional losses as well as the effect of valves overlapping. The model is tested for 2000, 3000 and 4000 rpm of engine speed and validated using experimental engine data. Results showed that the engine is able to simulate engine's combustion process and produce reasonable prediction. However, by comparing with experimental data, major discrepancy is noticeable especially on the 2000 and 4000 rpm prediction. At low and high engine speed, simulated cylinder pressures tend to under predict the measured data. Whereas the cylinder temperatures always tend to over predict the measured data at all engine speed. The most accurate prediction is obtained at medium engine speed of 3000 rpm. Appropriate wall heat transfer setup is vital for more precise calculation of cylinder pressure and temperature. More heat loss to the wall can lower cylinder temperature. On the hand, more heat converted to the useful work mean an increase in cylinder pressure. Thus, instead of wall heat transfer setup, the Wiebe combustion parameters are needed to be carefully evaluated for better results.

  4. Development of engineering drawing ability for emerging engineering education

    Science.gov (United States)

    Guo, Jian-Wen; Cao, Xiao-Chang; Xie, Li; Jin, Jian-Jun; Wang, Chu-Diao

    2017-09-01

    Students majoring in engineering is required by the emerging engineering education (3E) in the aspect of their ability of engineering drawing. This paper puts forward training mode of engineering drawing ability for 3E. This mode consists of three kinds of training including training in courses, training in competitions and training in actual demand. We also design the feasible implementation plan and supplies viable references to carry out the mode.

  5. Modular co-culture engineering, a new approach for metabolic engineering.

    Science.gov (United States)

    Zhang, Haoran; Wang, Xiaonan

    2016-09-01

    With the development of metabolic engineering, employment of a selected microbial host for accommodation of a designed biosynthetic pathway to produce a target compound has achieved tremendous success in the past several decades. Yet, increasing requirements for sophisticated microbial biosynthesis call for establishment and application of more advanced metabolic engineering methodologies. Recently, important progress has been made towards employing more than one engineered microbial strains to constitute synthetic co-cultures and modularizing the biosynthetic labor between the co-culture members in order to improve bioproduction performance. This emerging approach, referred to as modular co-culture engineering in this review, presents a valuable opportunity for expanding the scope of the broad field of metabolic engineering. We highlight representative research accomplishments using this approach, especially those utilizing metabolic engineering tools for microbial co-culture manipulation. Key benefits and major challenges associated with modular co-culture engineering are also presented and discussed. Copyright © 2016 International Metabolic Engineering Society. Published by Elsevier Inc. All rights reserved.

  6. Predictors of Associate's Degree Completion in Engineering and Engineering Technologies

    Science.gov (United States)

    Reys-Nickel, Lynsey L.

    The purpose of this ex post facto study was to describe completers and non-completers of associate's degree programs in engineering and engineering technologies and determine whether and to what extent completion in these programs is a function of selected student-related variables and institutional variables. Data from the 2004/2009 Beginning Postsecondary Students Longitudinal Study (BPS: 04/09) of associate's degree completers and non-completers in engineering and engineering technologies were accessed and analyzed through PowerStats, a web-based data analysis tool from National Center for Education Statistics (NCES). Descriptive data indicated that, proportionally, engineering and engineering technologies completers were mostly White, married, middle income, employed part-time, enrolled full-time, did not hold a high school diploma or certificate, completed Trigonometry/Algebra II, had a father who's highest education level was an associate's degree, but did not know their mother's highest level of education, completed remedial coursework, and started college with the goal of earning an associate's degree. While more males enrolled in the programs, males and females demonstrated similar completion rates, proportionally--with females showing a slightly higher percentage of completion. Results from the logistic regression further indicated that the variables significant to completion in associate's degree programs in engineering and engineering technologies were gender and enrollment size. Findings suggested that female students were more likely to earn the degree, and that the larger the institution, the more likely the student would become a completer. However, since a major limitation of the study was the small weighted sample size, the results of the study are inconclusive in terms of the extent to which the findings can be generalized to the population of students in associate's degree programs in engineering and engineering technologies. This study fills a

  7. 78 FR 22168 - Airworthiness Directives; International Aero Engines AG Turbofan Engines

    Science.gov (United States)

    2013-04-15

    ... Airworthiness Directives; International Aero Engines AG Turbofan Engines AGENCY: Federal Aviation Administration... International Aero Engines AG (IAE), V2525-D5 and V2528-D5 turbofan engines, with a certain No. 4 bearing... turbofan engines, serial numbers V20001 through V20285, with No. 4 bearing internal scavenge tube, part...

  8. Engineering Review Information System

    Science.gov (United States)

    Grems, III, Edward G. (Inventor); Henze, James E. (Inventor); Bixby, Jonathan A. (Inventor); Roberts, Mark (Inventor); Mann, Thomas (Inventor)

    2015-01-01

    A disciplinal engineering review computer information system and method by defining a database of disciplinal engineering review process entities for an enterprise engineering program, opening a computer supported engineering item based upon the defined disciplinal engineering review process entities, managing a review of the opened engineering item according to the defined disciplinal engineering review process entities, and closing the opened engineering item according to the opened engineering item review.

  9. Studying Engineering Practice

    DEFF Research Database (Denmark)

    Buch, Anders

    2015-01-01

    The study of engineering practices has been the focus of Engineering Studies over the last three decades. Theses studies have used ethnographic and grounded methods in order to investigate engineering practices as they unfold in natural settings - in workplaces and engineering education. However......, engineering studies have not given much attention to conceptually clarifying what should be understood by 'engineering practices' and more precisely account for the composition and organization of the entities and phenomena that make up the practices. This chapter investigates and discusses how a 'practice...... will draw out some methodological consequences and discuss the ramifications of a practice theoretical approach for Engineering Studies....

  10. Systems Engineering Leadership Development: Advancing Systems Engineering Excellence

    Science.gov (United States)

    Hall, Phil; Whitfield, Susan

    2011-01-01

    This slide presentation reviews the Systems Engineering Leadership Development Program, with particular emphasis on the work being done in the development of systems engineers at Marshall Space Flight Center. There exists a lack of individuals with systems engineering expertise, in particular those with strong leadership capabilities, to meet the needs of the Agency's exploration agenda. Therefore there is a emphasis on developing these programs to identify and train systems engineers. The presentation reviews the proposed MSFC program that includes course work, and developmental assignments. The formal developmental programs at the other centers are briefly reviewed, including the Point of Contact (POC)

  11. Globalization and Organizational Change: Engineers' Experiences and Their Implications for Engineering Education

    Science.gov (United States)

    Lucena, Juan C.

    2006-01-01

    The demand for flexible engineers presents significant challenges to engineering education. Among these is the need for engineers to be prepared to understand and deal with organizational change. Yet engineering education and research on engineers have overlooked the impact of organizational change on engineering work. After outlining the impact…

  12. Book of abstracts Chemical Engineering: IV All-Russian Conference on chemical engineering, All-Russian Youth Conference on chemical engineering, All-Russian school on chemical engineering for young scientists and specialists. Chemical engineering of nanomaterials. Energy- and resource-saving chemical-engineering processes and problems of their intensification. Processes and apparatuses of chemical engineering, chemical cybernetics. Ecological problems of chemical engineering and related fields

    International Nuclear Information System (INIS)

    Zakhodyaeva, Yu.A.; Belova, V.V.

    2012-01-01

    In the given volume of abstracts of the IV All-Russian Conference on chemical engineering, All-Russian Youth Conference on chemical engineering, All-Russian school on chemical engineering for young scientists and specialists (Moscow, March 18-23, 2012) there are the abstracts of the reports concerning chemical engineering of nanomaterials, energy- and resource-saving chemical-engineering processes, processes and apparatuses of chemical engineering, chemical cybernetics, ecological problems of chemical engineering and related fields. The abstracts deal with state-of-the-art and future development of theoretical and experimental investigations as well as with experience in practical realization of development works in the field of chemical engineering and relative areas [ru

  13. 78 FR 1776 - Airworthiness Directives; International Aero Engines AG Turbofan Engines

    Science.gov (United States)

    2013-01-09

    ... Engines AG Turbofan Engines AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Notice of proposed... Aero Engines AG (IAE), V2525-D5 and V2528-D5 turbofan engines, with a certain number (No.) 4 bearing... proposed AD. Discussion We received a report of a fire warning on an IAE V2525 turbofan engine shortly...

  14. Complete genome sequence of Truepera radiovictrix type strain (RQ-24).

    Science.gov (United States)

    Ivanova, Natalia; Rohde, Christine; Munk, Christine; Nolan, Matt; Lucas, Susan; Del Rio, Tijana Glavina; Tice, Hope; Deshpande, Shweta; Cheng, Jan-Fang; Tapia, Roxane; Han, Cliff; Goodwin, Lynne; Pitluck, Sam; Liolios, Konstantinos; Mavromatis, Konstantinos; Mikhailova, Natalia; Pati, Amrita; Chen, Amy; Palaniappan, Krishna; Land, Miriam; Hauser, Loren; Chang, Yun-Juan; Jeffries, Cynthia D; Brambilla, Evelyne; Rohde, Manfred; Göker, Markus; Tindall, Brian J; Woyke, Tanja; Bristow, James; Eisen, Jonathan A; Markowitz, Victor; Hugenholtz, Philip; Kyrpides, Nikos C; Klenk, Hans-Peter; Lapidus, Alla

    2011-02-22

    Truepera radiovictrix Albuquerque et al. 2005 is the type species of the genus Truepera within the phylum "Deinococcus/Thermus". T. radiovictrix is of special interest not only because of its isolated phylogenetic location in the order Deinococcales, but also because of its ability to grow under multiple extreme conditions in alkaline, moderately saline, and high temperature habitats. Of particular interest is the fact that, T. radiovictrix is also remarkably resistant to ionizing radiation, a feature it shares with members of the genus Deinococcus. This is the first completed genome sequence of a member of the family Trueperaceae and the fourth type strain genome sequence from a member of the order Deinococcales. The 3,260,398 bp long genome with its 2,994 protein-coding and 52 RNA genes consists of one circular chromosome and is a part of the Genomic Encyclopedia of Bacteria and Archaea project.

  15. Complete genome sequence of Truepera radiovictrix type strain (RQ-24T)

    Energy Technology Data Exchange (ETDEWEB)

    Ivanova, N [U.S. Department of Energy, Joint Genome Institute; Rohde, Christine [DSMZ - German Collection of Microorganisms and Cell Cultures GmbH, Braunschweig, Germany; Munk, Christine [Joint Genome Institute, Walnut Creek, California; Nolan, Matt [Joint Genome Institute, Walnut Creek, California; Lucas, Susan [Joint Genome Institute, Walnut Creek, California; Glavina Del Rio, Tijana [Joint Genome Institute, Walnut Creek, California; Tice, Hope [Joint Genome Institute, Walnut Creek, California; Deshpande, Shweta [Joint Genome Institute, Walnut Creek, California; Cheng, Jan-Fang [Joint Genome Institute, Walnut Creek, California; Tapia, Roxanne [Los Alamos National Laboratory (LANL); Han, Cliff [Los Alamos National Laboratory (LANL); Goodwin, Lynne A. [Los Alamos National Laboratory (LANL); Pitluck, Sam [Joint Genome Institute, Walnut Creek, California; Liolios, Konstantinos [Joint Genome Institute, Walnut Creek, California; Mavromatis, K [U.S. Department of Energy, Joint Genome Institute; Pati, Amrita [U.S. Department of Energy, Joint Genome Institute; Chen, Amy [Joint Genome Institute, Walnut Creek, California; Palaniappan, Krishna [Joint Genome Institute, Walnut Creek, California; Land, Miriam L [ORNL; Hauser, Loren John [ORNL; Chang, Yun-Juan [ORNL; Jeffries, Cynthia [Oak Ridge National Laboratory (ORNL); Brambilla, Evelyne-Marie [DSMZ - German Collection of Microorganisms and Cell Cultures GmbH, Braunschweig, Germany; Rohde, Manfred [HZI - Helmholtz Centre for Infection Research, Braunschweig, Germany; Goker, Markus [DSMZ - German Collection of Microorganisms and Cell Cultures GmbH, Braunschweig, Germany; Tindall, Brian [DSMZ - German Collection of Microorganisms and Cell Cultures GmbH, Braunschweig, Germany; Woyke, Tanja [Joint Genome Institute, Walnut Creek, California; Bristow, James [Joint Genome Institute, Walnut Creek, California; Eisen, Jonathan [Joint Genome Institute, Walnut Creek, California; Markowitz, Victor [Joint Genome Institute, Walnut Creek, California; Hugenholtz, Philip [U.S. Department of Energy, Joint Genome Institute; Kyrpides, Nikos C [Joint Genome Institute, Walnut Creek, California; Klenk, Hans-Peter [DSMZ - German Collection of Microorganisms and Cell Cultures GmbH, Braunschweig, Germany; Lapidus, Alla L. [Joint Genome Institute, Walnut Creek, California

    2011-01-01

    Truepera radiovictrix Albuquerque et al. 2005 is the type species of the genus Truepera within the phylum Deinococcus/Thermus. T. radiovictrix is of special interest not only because of its isolated phylogenetic location in the order Deinococcales, but also because of its ability to grow under multiple extreme conditions in alkaline, moderately saline, and high temperature habitats. Of particular interest is the fact that, T. radiovictrix is also remarkably resistant to ionizing radiation, a feature it shares with members of the genus Deinococcus. This is the first completed genome sequence of a member of the family Trueperaceae and the fourth type strain genome sequence from a member of the order Deinococcales. The 3,260,398 bp long genome with its 2,994 protein-coding and 52 RNA genes consists of one circular chromosome and is a part of the Genomic Encyclopedia of Bacteria and Archaea project.

  16. Engineering mechanics

    CERN Document Server

    Gross, Dietmar; Schröder, Jörg; Wall, Wolfgang A; Rajapakse, Nimal

    Statics is the first volume of a three-volume textbook on Engineering Mechanics. The authors, using a time-honoured straightforward and flexible approach, present the basic concepts and principles of mechanics in the clearest and simplest form possible to advanced undergraduate engineering students of various disciplines and different educational backgrounds. An important objective of this book is to develop problem solving skills in a systematic manner. Another aim of this volume is to provide engineering students as well as practising engineers with a solid foundation to help them bridge the gap between undergraduate studies on the one hand and advanced courses on mechanics and/or practical engineering problems on the other. The book contains numerous examples, along with their complete solutions. Emphasis is placed upon student participation in problem solving. The contents of the book correspond to the topics normally covered in courses on basic engineering mechanics at universities and colleges. Now in i...

  17. Software Engineering Guidebook

    Science.gov (United States)

    Connell, John; Wenneson, Greg

    1993-01-01

    The Software Engineering Guidebook describes SEPG (Software Engineering Process Group) supported processes and techniques for engineering quality software in NASA environments. Three process models are supported: structured, object-oriented, and evolutionary rapid-prototyping. The guidebook covers software life-cycles, engineering, assurance, and configuration management. The guidebook is written for managers and engineers who manage, develop, enhance, and/or maintain software under the Computer Software Services Contract.

  18. Formalization of the engineering science discipline - knowledge engineering

    Science.gov (United States)

    Peng, Xiao

    Knowledge is the most precious ingredient facilitating aerospace engineering research and product development activities. Currently, the most common knowledge retention methods are paper-based documents, such as reports, books and journals. However, those media have innate weaknesses. For example, four generations of flying wing aircraft (Horten, Northrop XB-35/YB-49, Boeing BWB and many others) were mostly developed in isolation. The subsequent engineers were not aware of the previous developments, because these projects were documented such which prevented the next generation of engineers to benefit from the previous lessons learned. In this manner, inefficient knowledge retention methods have become a primary obstacle for knowledge transfer from the experienced to the next generation of engineers. In addition, the quality of knowledge itself is a vital criterion; thus, an accurate measure of the quality of 'knowledge' is required. Although qualitative knowledge evaluation criteria have been researched in other disciplines, such as the AAA criterion by Ernest Sosa stemming from the field of philosophy, a quantitative knowledge evaluation criterion needs to be developed which is capable to numerically determine the qualities of knowledge for aerospace engineering research and product development activities. To provide engineers with a high-quality knowledge management tool, the engineering science discipline Knowledge Engineering has been formalized to systematically address knowledge retention issues. This research undertaking formalizes Knowledge Engineering as follows: 1. Categorize knowledge according to its formats and representations for the first time, which serves as the foundation for the subsequent knowledge management function development. 2. Develop an efficiency evaluation criterion for knowledge management by analyzing the characteristics of both knowledge and the parties involved in the knowledge management processes. 3. Propose and develop an

  19. Advancing Systems Engineering Excellence: The Marshall Systems Engineering Leadership Development Program

    Science.gov (United States)

    Hall, Philip; Whitfield, Susan

    2011-01-01

    As NASA undertakes increasingly complex projects, the need for expert systems engineers and leaders in systems engineering is becoming more pronounced. As a result of this issue, the Agency has undertaken an initiative to develop more systems engineering leaders through its Systems Engineering Leadership Development Program; however, the NASA Office of the Chief Engineer has also called on the field Centers to develop mechanisms to strengthen their expertise in systems engineering locally. In response to this call, Marshall Space Flight Center (MSFC) has developed a comprehensive development program for aspiring systems engineers and systems engineering leaders. This presentation will summarize the two-level program, which consists of a combination of training courses and on-the-job, developmental training assignments at the Center to help develop stronger expertise in systems engineering and technical leadership. In addition, it will focus on the success the program has had in its pilot year. The program hosted a formal kickoff event for Level I on October 13, 2009. The first class includes 42 participants from across MSFC and Michoud Assembly Facility (MAF). A formal call for Level II is forthcoming. With the new Agency focus on research and development of new technologies, having a strong pool of well-trained systems engineers is becoming increasingly more critical. Programs such as the Marshall Systems Engineering Leadership Development Program, as well as those developed at other Centers, help ensure that there is an upcoming generation of trained systems engineers and systems engineering leaders to meet future design challenges.

  20. Engineering tribology

    CERN Document Server

    Stachowiak, Gwidon; Batchelor, A W; Batchelor, Andrew W

    2005-01-01

    As with the previous edition, the third edition of Engineering Tribology provides a thorough understanding of friction and wear using technologies such as lubrication and special materials. Tribology is a complex topic with its own terminology and specialized concepts, yet is vitally important throughout all engineering disciplines, including mechanical design, aerodynamics, fluid dynamics and biomedical engineering. This edition includes updated material on the hydrodynamic aspects of tribology as well as new advances in the field of biotribology, with a focus throughout on the engineering ap

  1. 48 CFR 52.248-2 - Value Engineering-Architect-Engineer.

    Science.gov (United States)

    2010-10-01

    ... cycle cost consistent with required performance, reliability, quality, and safety. Value engineering... 48 Federal Acquisition Regulations System 2 2010-10-01 2010-10-01 false Value Engineering... Clauses 52.248-2 Value Engineering—Architect-Engineer. As prescribed in 48.201(f), insert the following...

  2. Progress in IFMIF Engineering Validation and Engineering Design Activities

    International Nuclear Information System (INIS)

    Heidinger, R.; Knaster, J.; Matsumoto, H.; Sugimoto, M.; Mosnier, A.; Arbeiter, F.; Baluc, N.; Cara, P.; Chel, S.; Facco, A.; Favuzza, P.; Heinzel, V.; Ibarra, A.; Massaut, V.; Micciche, G.; Nitti, F.S.; Theile, J.

    2013-01-01

    Highlights: ► The IFMIF/EVEDA project has entered into the crucial phase of concluding the Interim IFMIF Engineering Design Report. ► The IFMIF plant configuration has been established with the definition of five IFMIF facilities and of their interfaces. ► Three major prototypes of the IFMIF main systems have been designed and are being manufactured, commissioned and operated. -- Abstract: The International Fusion Materials Irradiation Facility (IFMIF) Engineering Design and Engineering Validation Activities (EVEDA) are being developed in a joint project in the framework of the Broader Approach (BA) Agreement between EU and Japan. This project has now entered into a crucial phase as the engineering design of IFMIF is now being formulated in a series of 3 subsequent phases for delivering an Interim IFMIF Engineering Design Report (IIEDR) by mid of 2013. Content of these phases is explained, including the plant configuration detailing the 5 IFMIF facilities and their systems. Together with the Engineering Design Activities, prototyping sub-projects are pursued in the Engineering Validation Activities which consist of the design, manufacturing and testing of the following prototypical systems: Linear IFMIF Prototype Accelerator (LIPAc), EVEDA Lithium Test Loop (ELTL), and High Flux Test Module (HFTM) with the prototypical helium cooling loop (HELOKA). Highlights are described from recent experiments in the Engineering Validation Activities

  3. Separated core turbofan engine; Core bunrigata turbofan engine

    Energy Technology Data Exchange (ETDEWEB)

    Saito, Y; Endo, M; Matsuda, Y; Sugiyama, N; Sugahara, N; Yamamoto, K [National Aerospace Laboratory, Tokyo (Japan)

    1996-04-01

    This report outlines the separated core turbofan engine. This engine is featured by parallel separated arrangement of a fan and core engine which are integrated into one unit in the conventional turbofan engine. In general, cruising efficiency improvement and noise reduction are achieved by low fan pressure ratio and low exhaust speed due to high bypass ratio, however, it causes various problems such as large fan and nacelle weight due to large air flow rate of a fan, and shift of an operating point affected by flight speed. The parallel separated arrangement is thus adopted. The stable operation of a fan and core engine is easily retained by independently operating air inlet unaffected by fan. The large degree of freedom of combustion control is also obtained by independent combustor. Fast response, simple structure and optimum aerodynamic design are easily achieved. This arrangement is also featured by flexibility of development and easy maintenance, and by various merits superior to conventional turbofan engines. It has no technological problems difficult to be overcome, and is also suitable for high-speed VTOL transport aircraft. 4 refs., 5 figs.

  4. First-year engineering students' views of the nature of engineering: implications for engineering programmes

    Science.gov (United States)

    Karataş, F. Ö.; Bodner, G. M.; Unal, Suat

    2016-01-01

    A study was conducted on the views of the nature of engineering held by 114 first-year engineering majors; the study built on prior work on views of the nature of science held by students, their instructors, and the general public. Open-coding analysis of responses to a 12-item questionnaire suggested that the participants held tacit beliefs that engineering (1) involves problem solving; (2) is a form of applied science; (3) involves the design of artefacts or systems; (4) is subject to various constraints; and (5) requires teamwork. These beliefs, however, were often unsophisticated, and significant aspects of the field of engineering as described in the literature on engineering practices were missing from the student responses. The results of this study are important because students' beliefs have a strong influence on what they value in a classroom situation, what they attend to in class, and how they choose to study for a course.

  5. Knowledge Expansion in Engineering Education: Engineering Technology as an Alternative

    Directory of Open Access Journals (Sweden)

    Kamsiah Mohd Ismail

    2015-07-01

    Full Text Available Abstract. The current and rising challenges in engineering education demand graduate engineers who are well-prepared to provide innovative solutions as technical specialists, system integrators and change agents. Realizing the importance of producing a highly competent manpower, the Malaysian Government has put considerable pressure to the universities to produce engineers who are competitive in the global market. Hence, this assignment of developing a highly competence engineering technologist workforce in support of the government policy highlights issues pertaining to the development and offering of practical-oriented programs as a knowledge expansion in engineering education at universities as envisioned by the Malaysian Government.  This paper evaluates the current scenario and examines the application-oriented programs of engineering technology education as practice in local institutions in Malaysia in comparisons to some universities abroad. It also investigates the challenges faced by university management in dealing with issues concerning national quality assurance and accreditation pertaining to the engineering technology education programs. Specifically, it analyzes the faculty planning of pedagogies in term of hands-on skills in teaching and learning. A key conclusion of this research is that Malaysian universities need to evaluate its engineering technology education strategies if they aim for quality assurance and accreditation to be established and aspire for successful attempts towards the creation of the requisite knowledge workers that Malaysia needs.Keywords: application-oriented, engineering education, engineering technology, hands-on skills, knowledge expansion 

  6. Fluids engineering

    International Nuclear Information System (INIS)

    Anon.

    1991-01-01

    Fluids engineering has played an important role in many applications, from ancient flood control to the design of high-speed compact turbomachinery. New applications of fluids engineering, such as in high-technology materials processing, biotechnology, and advanced combustion systems, have kept up unwaining interest in the subject. More accurate and sophisticated computational and measurement techniques are also constantly being developed and refined. On a more fundamental level, nonlinear dynamics and chaotic behavior of fluid flow are no longer an intellectual curiosity and fluid engineers are increasingly interested in finding practical applications for these emerging sciences. Applications of fluid technology to new areas, as well as the need to improve the design and to enhance the flexibility and reliability of flow-related machines and devices will continue to spur interest in fluids engineering. The objectives of the present seminar were: to exchange current information on arts, science, and technology of fluids engineering; to promote scientific cooperation between the fluids engineering communities of both nations, and to provide an opportunity for the participants and their colleagues to explore possible joint research programs in topics of high priority and mutual interest to both countries. The Seminar provided an excellent forum for reviewing the current state and future needs of fluids engineering for the two nations. With the Seminar ear-marking the first formal scientific exchange between Korea and the United States in the area of fluids engineering, the scope was deliberately left broad and general

  7. Software engineers and nuclear engineers: teaming up to do testing

    International Nuclear Information System (INIS)

    Kelly, D.; Cote, N.; Shepard, T.

    2007-01-01

    The software engineering community has traditionally paid little attention to the specific needs of engineers and scientists who develop their own software. Recently there has been increased recognition that specific software engineering techniques need to be found for this group of developers. In this case study, a software engineering group teamed with a nuclear engineering group to develop a software testing strategy. This work examines the types of testing that proved to be useful and examines what each discipline brings to the table to improve the quality of the software product. (author)

  8. Mean Value Engine Modelling of an SI Engine with EGR

    DEFF Research Database (Denmark)

    Føns, Michael; Müller, Martin; Chevalier, Alain

    1999-01-01

    Mean Value Engine Models (MVEMs) are simplified, dynamic engine models what are physically based. Such models are useful for control studies, for engine control system analysis and for model based engine control systems. Very few published MVEMs have included the effects of Exhaust Gas...... Recirculation (EGR). The purpose of this paper is to present a modified MVEM which includes EGR in a physical way. It has been tested using newly developed, very fast manifold pressure, manifold temperature, port and EGR mass flow sensors. Reasonable agreement has been obtained on an experimental engine...

  9. Infusing Engineering Concepts: Teaching Engineering Design

    Science.gov (United States)

    Daugherty, Jenny

    2012-01-01

    Engineering has gained considerable traction in many K-12 schools. However, there are several obstacles or challenges to an effective approach that leads to student learning. Questions such as where engineering best fits in the curriculum; how to include it authentically and appropriately; toward what educational end; and how best to prepare…

  10. Understanding engineering professionalism: a reflection on the rights of engineers.

    Science.gov (United States)

    Stieb, James A

    2011-03-01

    Engineering societies such as the National Society of Professional Engineers (NSPE) and associated entities have defined engineering and professionalism in such a way as to require the benefit of humanity (NSPE 2009a, Engineering Education Resource Document. NSPE Position Statements. Governmental Relations). This requirement has been an unnecessary and unfortunate "add-on." The trend of the profession to favor the idea of requiring the benefit of humanity for professionalism violates an engineer's rights. It applies political pressure that dissuades from inquiry, approaches to new knowledge and technologies, and the presentation, publication, and use of designs and research findings. Moreover, a more politically neutral definition of engineering and/or professionalism devoid of required service or benefit to mankind does not violate adherence to strong ethical standards.

  11. How Engineers Negotiate Domain Boundaries in a Complex, Interdisciplinary Engineering Project

    Science.gov (United States)

    Panther, Grace; Montfort, Devlin; Pirtle, Zachary

    2017-01-01

    Engineering educators have an essential role in preparing engineers to work in a complex, interdisciplinary workforce. While much engineering education focuses on teaching students to develop disciplinary expertise in specific engineering domains, there is a strong need to teach engineers about the knowledge that they develop or use in their work (Bucciarelli 1994, Allenby Sarewitz, 2011; Frodeman, 2013). The purpose of this research is to gain a better understanding of the knowledge systems of practicing engineers through observations of their practices such that the insights learned can guide future education efforts. Using an example from a complex and interdisciplinary engineering project, this paper presents a case study overviewing the types of epistemological (or knowledge-acquiring or using) complexities that engineers navigate. Specifically, we looked at a discussion of the thermal design of a CubeSat that occurred during an engineering review at NASA. We analyzed the review using a framework that we call 'peak events', or pointed discussions between reviewers, project engineers, and managers. We examined the dialog within peak events to identify the ways that knowledge was brought to bear, highlighting discussions of uncertainty and the boundaries of knowledge claims. We focus on one example discussion surrounding the thermal design of the CubeSat, which provides a particularly thorough example of a knowledge system since the engineers present explained, justified, negotiated, and defended knowledge within a social setting. Engineering students do not get much practice or instruction in explicitly negotiating knowledge systems and epistemic standards in this way. We highlight issues that should matter to engineering educators, such as the need to discuss what level of uncertainty is sufficient and the need to negotiate boundaries of system responsibility. Although this analysis is limited to a single discussion or 'peak event', our case shows that this

  12. Be a Professional - Be Licensed! - Take the agricultural engineering professional engineering exam

    Science.gov (United States)

    Between October 2005 and October 2007, only 78 Agricultural Engineers took the professional engineering (PE) exam in the field of Agricultural Engineering, while the other 406 registered Agricultural Engineering Examinees took tests offer by other engineering disciplines. With the decline in partic...

  13. Engineering Encounters: An Engineering Design Process for Early Childhood

    Science.gov (United States)

    Lottero-Perdue, Pamela; Bowditch, Michelle; Kagan, Michelle; Robinson-Cheek, Linda; Webb, Tedra; Meller, Megan; Nosek, Theresa

    2016-01-01

    This column presents ideas and techniques to enhance your science teaching. This month's issue shares information about trying (again) to engineer an egg package. Engineering is an essential part of science education, as emphasized in the "Next Generation Science Standards" (NGSS Lead States 2013). Engineering practices and performance…

  14. Engineering Background: Modern Formats and Challenges of Conceptual Engineering

    Science.gov (United States)

    Khamidullina, A. F.; Kuzmina, M. A.; Khusnutdinova, E. M.; Konakhina, I. A.

    2017-09-01

    This paper describes the analysis of problems and development perspectives of engineering education in our and other countries. Special attention is given to modern formats of education that motivate creative efforts of engineers-to-be as well as issues of conceptual engineering taking the challenges of modernity into account.

  15. Protein engineering for metabolic engineering: current and next-generation tools

    Science.gov (United States)

    Marcheschi, Ryan J.; Gronenberg, Luisa S.; Liao, James C.

    2014-01-01

    Protein engineering in the context of metabolic engineering is increasingly important to the field of industrial biotechnology. As the demand for biologically-produced food, fuels, chemicals, food additives, and pharmaceuticals continues to grow, the ability to design and modify proteins to accomplish new functions will be required to meet the high productivity demands for the metabolism of engineered organisms. This article reviews advances of selecting, modeling, and engineering proteins to improve or alter their activity. Some of the methods have only recently been developed for general use and are just beginning to find greater application in the metabolic engineering community. We also discuss methods of generating random and targeted diversity in proteins to generate mutant libraries for analysis. Recent uses of these techniques to alter cofactor use, produce non-natural amino acids, alcohols, and carboxylic acids, and alter organism phenotypes are presented and discussed as examples of the successful engineering of proteins for metabolic engineering purposes. PMID:23589443

  16. Engineering surveying

    CERN Document Server

    Schofield, W

    2001-01-01

    The aim of Engineering Surveying has always been to impart and develop a clear understanding of the basic topics of the subject. The author has fully revised the book to make it the most up-to-date and relevant textbook available on the subject.The book also contains the latest information on trigonometric levelling, total stations and one-person measuring systems. A new chapter on satellites ensures a firm grasp of this vitally important topic.The text covers engineering surveying modules for civil engineering students on degree courses and forms a reference for the engineering surveying module in land surveying courses. It will also prove to be a valuable reference for practitioners.* Simple clear introduction to surveying for engineers* Explains key techniques and methods* Details reading systems and satellite position fixing

  17. Book of abstracts Chemical Engineering: IV All-Russian Conference on chemical engineering, All-Russian Youth Conference on chemical engineering, All-Russian school on chemical engineering for young scientists and specialists. Engineering of polymers and composite materials. Catalysis in chemical engineering

    International Nuclear Information System (INIS)

    Zakhodyaeva, Yu.A.; Belova, V.V.

    2012-01-01

    In the given volume of abstracts of the IV All-Russian Conference on chemical engineering, All-Russian Youth Conference on chemical engineering, All-Russian school on chemical engineering for young scientists and specialists (Moscow, March 18-23, 2012) there are the abstracts of the reports concerning polymer and composite materials technology as well as catalysis in chemical engineering. The abstracts deal with state-of-the-art and future development of theoretical and experimental investigations as well as with experience in practical realization of development works in the field of chemical engineering and relative areas [ru

  18. Welding engineering manual for constructing engineers. Pt. 2

    International Nuclear Information System (INIS)

    Neumann, A.

    1986-01-01

    The manual is a real treasure trove of knowledge and experience for the statics expert, the constructing engineer, and the welding engineer, who have to do with design and dimensioning of welding engineering work for steel structures, bridges, boilers, vessels, and pipes. Many practical examples are given together with numerous data that provide helpful information for the task of technical and economic design and dimensioning. Determination of efficient and appropriate cross-sectional dimensions and materials is the main goal of the manual. Structural steel engineering and installations subject to monitoring and inspection such as boilers, pipings, pressure vessels, and nuclear installations are the subject fields dealt with in separate chapters. The dimensioning rules presented are based on the regulations and technical codes valid in the GDR and the FRG. The catalogue of technical rules of the FRG concerning structural steel engineering and installations as above are given in supplementary chapters. (orig./HP) [de

  19. Fundamentals of Aerospace Engineering: An introductory course to aeronautical engineering

    OpenAIRE

    Soler, Manuel

    2014-01-01

    Fundamentals of Aerospace Engineering is a text book that provides an introductory, thorough overview of aeronautical engineering, and it is aimed at serving as reference for an undergraduate course on aerospace engineering.

  20. 40 CFR 1033.130 - Instructions for engine remanufacturing or engine installation.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 32 2010-07-01 2010-07-01 false Instructions for engine remanufacturing or engine installation. 1033.130 Section 1033.130 Protection of Environment ENVIRONMENTAL... and Related Requirements § 1033.130 Instructions for engine remanufacturing or engine installation. (a...

  1. 78 FR 9003 - Airworthiness Directives; Engine Alliance Turbofan Engines

    Science.gov (United States)

    2013-02-07

    ... Turbofan Engines AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Notice of proposed rulemaking... GP7270 and GP7277 turbofan engines. This proposed AD was prompted by damage to the high-pressure... GP7277 turbofan engines with a high-pressure compressor (HPC) stage 6 disk, part number (P/N) 382-100-505...

  2. Engineering Programs of Tomorrow: The Role of Agricultural Engineering.

    Science.gov (United States)

    Edwards, Donald M.

    Due to rapid growth of societal and technological endeavors, engineers of the future will require greater technical competence. At the same time, engineering will become more people oriented with greater emphasis placed on people input into decision making. As a result, engineering education must not only provide improved technical education but…

  3. First-year Engineering Education with the Creative Electrical Engineering Laboratory

    Science.gov (United States)

    Tsukamoto, Takehiko; Sugito, Tetsumasa; Ozeki, Osamu; Ushiroda, Sumio

    The Department of Electrical and Electronic Engineering in Toyota National College of Technology has put great emphasis on fundamental subjects. We introduced the creative electrical engineering laboratory into the first-year engineering education since 1998. The laboratory concentrates on the practice exercise. The final questionnaire of students showed that our first-year education is very effective to promote students motivation and their scholastic ability in engineering.

  4. Main engineering features driving design concept and engineering design constraints

    International Nuclear Information System (INIS)

    Saito, Ryusei; Kobayashi, Takeshi; Yamada, Masao

    1987-09-01

    Major engineering design philosophies are described, which are essential bases for an engineering design and may have significant impacts on a reactor design concept. Those design philosophies are classified into two groups, engineering design drivers and engineering design constraints. The design drivers are featured by the fact that a designer is free to choose and the choice may be guided by his opinion, such as coil system, a mechanical configuration, a tritium breeding scenario, etc.. The design constraints may follow a natural law or engineering limit, such as material strength, coil current density, and so on. (author)

  5. Trend of supersonic aircraft engine. Choonsokukiyo engine no doko

    Energy Technology Data Exchange (ETDEWEB)

    Yashima, S [Ishikawajima-Harima Heavy Industries, Co. Ltd., Tokyo (Japan)

    1994-05-01

    The present paper explained the R and D trend of supersonic aircraft engine in Europe, USA and Japan. Taking the high speed flight resistance into consideration, the engine must be characterized by its high exhaust gas speed and high specific thrust (ratio of thrust to the airflow rate) to secure strong thrust by a low airflow rate. Therefore, the turbojet is appropriate. However to reduce the fuel consumption during the cruising flight, the turbofan is normally used with a low by-pass ratio of 0.2 to 0.9. The thrust-to-weight ratio (thrust per unit weight) of low by-pass ratio turbofan engine equipped with afterburner is 7 to 8 in case of stronger thrust than 70kN. Its target value of development is 10. The specific thrust which is a performance parameter of engine exceeds 120s for the fighter engine and is about 30s for the passenger plane engine. The turbine inlet temperature is 2073K at the stage of element research. The overall pressure ratio ranges from 25 to 30. The reheating turbofan engine experimentally built for the research in Japan is 34kN in thrust and 7 in thrust-to-weight ratio. 8 refs., 9 figs.

  6. Introduction to tissue engineering and application for cartilage engineering.

    Science.gov (United States)

    de Isla, N; Huseltein, C; Jessel, N; Pinzano, A; Decot, V; Magdalou, J; Bensoussan, D; Stoltz, J-F

    2010-01-01

    Tissue engineering is a multidisciplinary field that applies the principles of engineering, life sciences, cell and molecular biology toward the development of biological substitutes that restore, maintain, and improve tissue function. In Western Countries, tissues or cells management for clinical uses is a medical activity governed by different laws. Three general components are involved in tissue engineering: (1) reparative cells that can form a functional matrix; (2) an appropriate scaffold for transplantation and support; and (3) bioreactive molecules, such as cytokines and growth factors that will support and choreograph formation of the desired tissue. These three components may be used individually or in combination to regenerate organs or tissues. Thus the growing development of tissue engineering needs to solve four main problems: cells, engineering development, grafting and safety studies.

  7. Mechanical engineer's handbook

    CERN Document Server

    Marghitu, Dan B

    2001-01-01

    The Mechanical Engineer's Handbook was developed and written specifically to fill a need for mechanical engineers and mechanical engineering students throughout the world. With over 1000 pages, 550 illustrations, and 26 tables the Mechanical Engineer's Handbook is very comprehensive, yet affordable, compact, and durable. The Handbook covers all major areas of mechanical engineering with succinct coverage of the definitions, formulas, examples, theory, proofs, and explanations of all principle subject areas. The Handbook is an essential, practical companion for all mechanic

  8. 76 FR 77108 - Airworthiness Directives; International Aero Engines Turbofan Engines

    Science.gov (United States)

    2011-12-12

    ... Airworthiness Directives; International Aero Engines Turbofan Engines AGENCY: Federal Aviation Administration...-D5, V2530-A5, and V2533-A5 turbofan engines. This AD was prompted by three reports of high- pressure..., V2524-A5, V2525-D5, V2527-A5, V2527E-A5, V2527M-A5, V2528- D5, V2530-A5, and V2533-A5 turbofan engines...

  9. Method Engineering: Engineering of Information Systems Development Methods and Tools

    OpenAIRE

    Brinkkemper, J.N.; Brinkkemper, Sjaak

    1996-01-01

    This paper proposes the term method engineering for the research field of the construction of information systems development methods and tools. Some research issues in method engineering are identified. One major research topic in method engineering is discussed in depth: situational methods, i.e. the configuration of a project approach that is tuned to the project at hand. A language and support tool for the engineering of situational methods are discussed.

  10. I "Still" Wanna Be an Engineer! Women, Education and the Engineering Profession

    Science.gov (United States)

    Gill, Judith; Sharp, Rhonda; Mills, Julie; Franzway, Suzanne

    2008-01-01

    Women's low enrolment in post-school engineering degrees continues to be a problem for engineering faculties and the profession generally. A qualitative interview-based study of Australian women engineers across the range of engineering disciplines showed the relevance of success in math and science at school to their enrolling in engineering at…

  11. Lineage of global civil engineering. Global civil engineering no keifu

    Energy Technology Data Exchange (ETDEWEB)

    Hashimoto, M

    1994-04-15

    This paper considers which way the global civil engineering should go in the future. Civil engineering has now a paradigm with a new dimension debuted as the global environmental problems are taken up specifically. Achieving the target of civil engineering requires a critical review that how the cost effect and efficiency discussions in only the dimensions of the conventional technologies and economies can be incorporated into the dimensions and measures of new fields to create the new horizons. Conceiving the relationship between civil engineered structures and environmental climate encounters the indispensable judgment criterion on how such social scientific conditions as weather, culture, religion, economy, and politics are combined to reach a judgment. The global civil engineering is desired to have the ideas and directional role to work on the ultimate assignment of environment and development called a global environmental problem analytically, comprehensively, innovatively and creatively as the civil engineering science, rather than as a mere existence of one area of the advanced civil engineering science. 5 refs., 1 tab.

  12. The good engineer: giving virtue its due in engineering ethics.

    Science.gov (United States)

    Harris, Charles E

    2008-06-01

    During the past few decades, engineering ethics has been oriented towards protecting the public from professional misconduct by engineers and from the harmful effects of technology. This "preventive ethics" project has been accomplished primarily by means of the promulgation of negative rules. However, some aspects of engineering professionalism, such as (1) sensitivity to risk (2) awareness of the social context of technology, (3) respect for nature, and (4) commitment to the public good, cannot be adequately accounted for in terms of rules, certainly not negative rules. Virtue ethics is a more appropriate vehicle for expressing these aspects of engineering professionalism. Some of the unique features of virtue ethics are the greater place it gives for discretion and judgment and also for inner motivation and commitment. Four of the many professional virtues that are important for engineers correspond to the four aspects of engineering professionalism listed above. Finally, the importance of the humanities and social sciences in promoting these virtues suggests that these disciplines are crucial in the professional education of engineers.

  13. Becoming an Engineer or a Lady Engineer

    NARCIS (Netherlands)

    Liebrand, Janwillem; Udas, Pranita Bhushan

    2017-01-01

    In this article, using the Department of Irrigation in Nepal as a case study, we argue that professional performance in irrigation engineering and water resources development is gendered and normalised as ‘masculine’. In Nepal, the masculinity of professional performance in irrigation engineering is

  14. Using Notable Women in Environmental Engineering to Dispel Misperceptions of Engineers

    Science.gov (United States)

    Hoh, Yin Kiong

    2009-01-01

    This paper describes an activity the author has carried out with 72 high school science teachers to enable them to overcome their stereotypical perceptions of engineers. The activity introduced them to notable women in environmental engineering, and raised their awareness of these female engineers' contributions to engineering and society. The…

  15. Modern engineering thermodynamics

    CERN Document Server

    Balmer, Robert T

    2010-01-01

    Designed for use in a standard two-semester engineering thermodynamics course sequence. The first half of the text contains material suitable for a basic Thermodynamics course taken by engineers from all majors. The second half of the text is suitable for an Applied Thermodynamics course in mechanical engineering programs. The text has numerous features that are unique among engineering textbooks, including historical vignettes, critical thinking boxes, and case studies. All are designed to bring real engineering applications into a subject that can be somewhat abstract and mathematica

  16. Performance and driveline analyses of engine capacity in range extender engine hybrid vehicle

    Science.gov (United States)

    Praptijanto, Achmad; Santoso, Widodo Budi; Nur, Arifin; Wahono, Bambang; Putrasari, Yanuandri

    2017-01-01

    In this study, range extender engine designed should be able to meet the power needs of a power generator of hybrid electrical vehicle that has a minimum of 18 kW. Using this baseline model, the following range extenders will be compared between conventional SI piston engine (Baseline, BsL), engine capacity 1998 cm3, and efficiency-oriented SI piston with engine capacity 999 cm3 and 499 cm3 with 86 mm bore and stroke square gasoline engine in the performance, emission prediction of range extender engine, standard of charge by using engine and vehicle simulation software tools. In AVL Boost simulation software, range extender engine simulated from 1000 to 6000 rpm engine loads. The highest peak engine power brake reached up to 38 kW at 4500 rpm. On the other hand the highest torque achieved in 100 Nm at 3500 rpm. After that using AVL cruise simulation software, the model of range extended electric vehicle in series configuration with main components such as internal combustion engine, generator, electric motor, battery and the arthemis model rural road cycle was used to simulate the vehicle model. The simulation results show that engine with engine capacity 999 cm3 reported the economical performances of the engine and the emission and the control of engine cycle parameters.

  17. Systems Engineering Analysis

    Directory of Open Access Journals (Sweden)

    Alexei Serna M.

    2013-07-01

    Full Text Available The challenges proposed by the development of the new computer systems demand new guidance related to engineer´s education, because they will solve these problems. In the XXI century, system engineers must be able to integrate a number of topics and knowledge disciplines that complement that traditionally has been known as Computer Systems Engineering. We have enough software development engineers, today we need professional engineers for software integration, leaders and system architects that make the most of the technological development for the benefit of society, leaders that integrate sciences to the solutions they build and propose. In this article the current situation of Computer Systems Engineering is analyzed and is presented a theory proposing the need for modifying the approach Universities have given to these careers, to achieve the education of leader engineers according to the needs of this century.

  18. Fundamentals of electric power engineering engineering from electromagnetics to power systems

    CERN Document Server

    Ceraolo, Massimo

    2014-01-01

    At the basis of many sectors of engineering, electrical engineering deals with electricity phenomena involved in the transfer of energy and power. Professionals requiring a refresher course in this interdisciplinary branch need look no further than Fundamentals of Electric Power Engineering, which imparts tools and trade tricks to remembering basic concepts and grasping new developments. Even established engineers must supplement their careers with an invigorated knowledge base, and this comprehensive resource helps non-electrical engineers amass power system information quickly.

  19. Model-Based Systems Engineering in Concurrent Engineering Centers

    Science.gov (United States)

    Iwata, Curtis; Infeld, Samantha; Bracken, Jennifer Medlin; McGuire, Melissa; McQuirk, Christina; Kisdi, Aron; Murphy, Jonathan; Cole, Bjorn; Zarifian, Pezhman

    2015-01-01

    Concurrent Engineering Centers (CECs) are specialized facilities with a goal of generating and maturing engineering designs by enabling rapid design iterations. This is accomplished by co-locating a team of experts (either physically or virtually) in a room with a narrow design goal and a limited timeline of a week or less. The systems engineer uses a model of the system to capture the relevant interfaces and manage the overall architecture. A single model that integrates other design information and modeling allows the entire team to visualize the concurrent activity and identify conflicts more efficiently, potentially resulting in a systems model that will continue to be used throughout the project lifecycle. Performing systems engineering using such a system model is the definition of model-based systems engineering (MBSE); therefore, CECs evolving their approach to incorporate advances in MBSE are more successful in reducing time and cost needed to meet study goals. This paper surveys space mission CECs that are in the middle of this evolution, and the authors share their experiences in order to promote discussion within the community.

  20. Information engineering

    Energy Technology Data Exchange (ETDEWEB)

    Hunt, D.N.

    1997-02-01

    The Information Engineering thrust area develops information technology to support the programmatic needs of Lawrence Livermore National Laboratory`s Engineering Directorate. Progress in five programmatic areas are described in separate reports contained herein. These are entitled Three-dimensional Object Creation, Manipulation, and Transport, Zephyr:A Secure Internet-Based Process to Streamline Engineering Procurements, Subcarrier Multiplexing: Optical Network Demonstrations, Parallel Optical Interconnect Technology Demonstration, and Intelligent Automation Architecture.

  1. First year engineering students: Perceptions of engineers and engineering work amongst domestic and international students

    Directory of Open Access Journals (Sweden)

    Dawn Bennett

    2015-03-01

    Full Text Available Despite being well ahead of many other disciplines in establishing strong and evidence-based research and practice, engineering in many countries still experiences high rates of student and graduate attrition. One possible reason for this is that students enter engineering study without understanding the realities of either their degree program or engineering work, and without a sense of motivation and commitment. The research reported here aimed to extend understanding of first year engineering students’ thinking about their competencies, identity, self-efficacy, motivation, and career. The study involved over 1,100 first year engineering students enrolled in a common first year unit. Responses were coded using the Engineers Australia graduate competencies as a framework, and this paper reports findings from the most diverse cohort of students (n=260, of whom 49% were international students with English as their second language. The research identified differences between international and domestic students’ perceptions of self and of career competencies, possibly related to self-esteem. Implications include improved confidence and motivation to learn as students consider their strengths, interests and goals. Further, the research raises the need for analysis of international students’ cultural and educational background to determine how different cohorts of international students self-appraise and how they associate learning with their future careers.

  2. Fundamental of biomedical engineering

    CERN Document Server

    Sawhney, GS

    2007-01-01

    About the Book: A well set out textbook explains the fundamentals of biomedical engineering in the areas of biomechanics, biofluid flow, biomaterials, bioinstrumentation and use of computing in biomedical engineering. All these subjects form a basic part of an engineer''s education. The text is admirably suited to meet the needs of the students of mechanical engineering, opting for the elective of Biomedical Engineering. Coverage of bioinstrumentation, biomaterials and computing for biomedical engineers can meet the needs of the students of Electronic & Communication, Electronic & Instrumenta

  3. Engineering education research: Impacts of an international network of female engineers on the persistence of Liberian undergraduate women studying engineering

    Science.gov (United States)

    Rimer, Sara; Reddivari, Sahithya; Cotel, Aline

    2015-11-01

    As international efforts to educate and empower women continue to rise, engineering educators are in a unique position to be a part of these efforts by encouraging and supporting women across the world at the university level through STEM education and outreach. For the past two years, the University of Michigan has been a part of a grassroots effort to encourage and support the persistence of engineering female students at University of Liberia. This effort has led to the implementation of a leadership camp this past August for Liberian engineering undergraduate women, meant to: (i) to empower engineering students with the skills, support, and inspiration necessary to become successful and well-rounded engineering professionals in a global engineering market; and (ii) to strengthen the community of Liberian female engineers by building cross-cultural partnerships among students resulting in a international network of women engineers. This session will present qualitative research findings on the impact of this grassroots effort on Liberian female students? persistence in engineering, and the future directions of this work.

  4. 23rd International Conference on Industrial Engineering and Engineering Management 2016

    CERN Document Server

    Shen, Jiang; Dou, Runliang

    2017-01-01

    International Conference on Industrial Engineering and Engineering Management is sponsored by Chinese Industrial Engineering Institution, CMES, which is the unique national-level academic society of Industrial Engineering. The conference is held annually as the major event in this area. Being the largest and the most authoritative international academic conference held in China, it supplies an academic platform for the experts and the entrepreneurs in International Industrial Engineering and Management area to exchange their research results. Many experts in various fields from China and foreign countries gather together in the conference to review, exchange, summarize and promote their achievements in Industrial Engineering and Engineering Management fields. Some experts pay special attention to the current situation of the related techniques application in China as well as their future prospect, such as Industry 4.0, Green Product Design, Quality Control and Management, Supply Chain and logistics Management...

  5. Reliability and safety engineering

    CERN Document Server

    Verma, Ajit Kumar; Karanki, Durga Rao

    2016-01-01

    Reliability and safety are core issues that must be addressed throughout the life cycle of engineering systems. Reliability and Safety Engineering presents an overview of the basic concepts, together with simple and practical illustrations. The authors present reliability terminology in various engineering fields, viz.,electronics engineering, software engineering, mechanical engineering, structural engineering and power systems engineering. The book describes the latest applications in the area of probabilistic safety assessment, such as technical specification optimization, risk monitoring and risk informed in-service inspection. Reliability and safety studies must, inevitably, deal with uncertainty, so the book includes uncertainty propagation methods: Monte Carlo simulation, fuzzy arithmetic, Dempster-Shafer theory and probability bounds. Reliability and Safety Engineering also highlights advances in system reliability and safety assessment including dynamic system modeling and uncertainty management. Cas...

  6. Method Engineering: Engineering of Information Systems Development Methods and Tools

    NARCIS (Netherlands)

    Brinkkemper, J.N.; Brinkkemper, Sjaak

    1996-01-01

    This paper proposes the term method engineering for the research field of the construction of information systems development methods and tools. Some research issues in method engineering are identified. One major research topic in method engineering is discussed in depth: situational methods, i.e.

  7. Effect of Diesel Engine Converted to Sequential Port Injection Compressed Natural Gas Engine on the Cylinder Pressure vs Crank Angle in Variation Engine Speeds

    OpenAIRE

    Semin; Abdul R. Ismail; Rosli A. Bakar

    2009-01-01

    The diesel engine converted to compressed natural gas (CNG) engine effect is lower in performance. Problem statement: The hypothesis is that the lower performance of CNG engine is caused by the effect of lower in engine cylinder pressure. Are the CNG engine is lower cylinder pressure than diesel engine? This research is conducted to investigate the cylinder pressure of CNG engine as a new engine compared to diesel engine as a baseline engine. Approach: The research approach in this study is b...

  8. Hidden in plain view: feminists doing engineering ethics, engineers doing feminist ethics.

    Science.gov (United States)

    Riley, Donna

    2013-03-01

    How has engineering ethics addressed gender concerns to date? How have the ideas of feminist philosophers and feminist ethicists made their way into engineering ethics? What might an explicitly feminist engineering ethics look like? This paper reviews some major themes in feminist ethics and then considers three areas in which these themes have been taken up in engineering ethics to date. First, Caroline Whitbeck's work in engineering ethics integrates considerations from her own earlier writings and those of other feminist philosophers, but does not use the feminist label. Second, efforts to incorporate the Ethic of Care and principles of Social Justice into engineering have drawn on feminist scholarship and principles, but these commitments can be lost in translation to the broader engineering community. Third, the film Henry's Daughters brings gender considerations into the mainstream of engineering ethics, but does not draw on feminist ethics per se; despite the best intentions in broaching a difficult subject, the film unfortunately does more harm than good when it comes to sexual harassment education. I seek not only to make the case that engineers should pay attention to feminist ethics and engineering ethicists make more use of feminist ethics traditions in the field, but also to provide some avenues for how to approach integrating feminist ethics in engineering. The literature review and analysis of the three examples point to future work for further developing what might be called feminist engineering ethics.

  9. Designed by Engineers: An analysis of interactionaries with engineering students

    Directory of Open Access Journals (Sweden)

    Henrik Artman

    2014-12-01

    Full Text Available The aim of this study is to describe and analyze learning taking place in a collaborative design exercise involving engineering students. The students perform a time-constrained, open-ended, complex interaction design task, an “interactionary”. A multimodal learning perspective is used. We have performed detailed analyses of video recordings of the engineering students, including classifying aspects of interaction. Our results show that the engineering students carry out and articulate their design work using a technology-centred approach and focus more on the function of their designs than on aspects of interaction. The engineering students mainly make use of ephemeral communication strategies (gestures and speech rather than sketching in physical materials. We conclude that the interactionary may be an educational format that can help engineering students learn the messiness of design work. We further identify several constraints to the engineering students’ design learning and propose useful interventions that a teacher could make during an interactionary. We especially emphasize interventions that help engineering students-retain aspects of human-centered design throughout the design process. This study partially replicates a previous study which involved interaction design students.

  10. Emotional engineering

    CERN Document Server

    In an age of increasing complexity, diversification and change, customers expect services that cater to their needs and to their tastes. Emotional Engineering vol 2. describes how their expectations can be satisfied and managed throughout the product life cycle, if producers focus their attention more on emotion. Emotional engineering provides the means to integrate products to create a new social framework and develops services beyond product realization to create of value across a full lifetime.  14 chapters cover a wide range of topics that can be applied to product, process and industry development, with special attention paid to the increasing importance of sensing in the age of extensive and frequent changes, including: • Multisensory stimulation and user experience  • Physiological measurement • Tactile sensation • Emotional quality management • Mental model • Kansei engineering.   Emotional Engineering vol 2 builds on Dr Fukuda’s previous book, Emotional Engineering, and provides read...

  11. Systems engineering simplified

    CERN Document Server

    Cloutier, Robert; Bone, Mary Alice

    2015-01-01

    IntroductionOverviewDiscussion of Common TerminologyThe Case for Systems EngineeringA Brief History of Systems EngineeringSystem ExamplesSummaryThe System Life CycleManaging System Development-The Vee ModelSystem ProductionSystem Utilization and SupportSystem Retirement and DisposalOther Systems Engineering Development ModelsSpiral ModelAgile Model for Systems EngineeringSystem of InterestAbstraction and DecompositionIntegrationDeveloping and Managing RequirementsCyclone Requiremen

  12. Engineering of complex systems: The impact of systems engineering at NASA

    Science.gov (United States)

    Kludze, Ave-Klutse Kodzo Paaku

    The "true" impact or value of systems engineering to an organization unfortunately appears not to have been well-studied and understood. The principles of systems engineering are highly encouraged by NASA at all levels, and most practitioners, both internal and external to NASA, intuitively "believe" it adds some value to the development of complex systems by producing them faster, better and cheaper. This research, in trying to fill a gap that exists in the systems engineering literature, analyzes data collected within NASA and other sources external to NASA (INCOSE) for comparisons. Analyses involving a number of case studies performed on selected NASA projects are presented to draw attention to the impact systems engineering had or could have had on these projects. This research clearly shows that systems engineering does add value to projects within and outside NASA. The research results further demonstrate that systems engineering has been beneficial not only to NASA but also to organizations within which INCOSE members work. It was determined, however, that systems engineering does not operate in a vacuum and may not always guarantee success through mere application. During this research, it was discovered that the lack of or inadequate application of systems engineering in the development of complex systems may result in cost overruns, poor technical performance, project delays, and in some cases unmitigated risk with disastrous consequences including the loss of life and property. How much is saved (in terms of cost, schedule) or improved (in terms of technical performance) as a result of its implementation may never be known precisely, but by indirectly measuring its value or impact on a project, percentages of project budget spent on systems engineering activities and any schedule reductions or performance enhancements realized could be determined. According to this research, systems engineering is not a waste of time and resources; in most cases, it is

  13. Diesel Engine Tribology

    DEFF Research Database (Denmark)

    Christiansen, Christian Kim

    Recent years have seen an increase in the wear rate of engine bearings, subsequently followed by bearing failure, for the large two-stroke diesel engines used for ship propulsion. Here, the engine bearings include main, big end and crosshead bearings, with the bearing type used being the journal...... bearing, belonging to the class of ‘hydrodynamic bearings’. This implies that the load carrying capacity is generated by a relative movement of the involved components, i.e. avelocity-driven operation. For the engine application, the velocity stems from the engine RPM. However, to comply with the latest...

  14. Engineering qualifications for competence

    International Nuclear Information System (INIS)

    Levy, J.C.

    1990-01-01

    The Engineering Council has a responsibility across all fields of engineering to set standards for those who are registered as Chartered Engineers, Incorporated Engineers or Engineering Technicians. These standards amount to a basic specification of professional competence to which must be added the features needed in each different branch of engineering, such as nuclear, and each particular occupation, such as quality assurance. This article describes The Engineering Council's general standards and includes a guide to the roles and responsibilities which should lie within the domain of those who are registered with the Council. The concluding section describes the title of European Engineer and its relationship to the European Community directive governing the movement of professionals across community frontiers. (author)

  15. Engineering Encounters: Identifying an Engineering Design Problem

    Science.gov (United States)

    Chizek, Lisa; VanMeeteren, Beth; McDermott, Mark; Uhlenberg, Jill

    2018-01-01

    Engineering is an intriguing way for students to connect the design process with their knowledge of science (NRC 2012). This article describes the "Engineering a Pancake Recipe" design process which was created to make the structure and properties of matter more meaningful for fifth grade students. The whole pancake recipe engineering…

  16. Industrial Education. "Small Engines".

    Science.gov (United States)

    Parma City School District, OH.

    Part of a series of curriculum guides dealing with industrial education in junior high schools, this guide provides the student with information and manipulative experiences on small gasoline engines. Included are sections on shop adjustment, safety, small engines, internal combustion, engine construction, four stroke engines, two stroke engines,…

  17. Milestones in software engineering and knowledge engineering history: a comparative review.

    Science.gov (United States)

    del Águila, Isabel M; Palma, José; Túnez, Samuel

    2014-01-01

    We present a review of the historical evolution of software engineering, intertwining it with the history of knowledge engineering because "those who cannot remember the past are condemned to repeat it." This retrospective represents a further step forward to understanding the current state of both types of engineerings; history has also positive experiences; some of them we would like to remember and to repeat. Two types of engineerings had parallel and divergent evolutions but following a similar pattern. We also define a set of milestones that represent a convergence or divergence of the software development methodologies. These milestones do not appear at the same time in software engineering and knowledge engineering, so lessons learned in one discipline can help in the evolution of the other one.

  18. Harmonic engine

    Science.gov (United States)

    Bennett, Charles L [Livermore, CA

    2009-10-20

    A high efficiency harmonic engine based on a resonantly reciprocating piston expander that extracts work from heat and pressurizes working fluid in a reciprocating piston compressor. The engine preferably includes harmonic oscillator valves capable of oscillating at a resonant frequency for controlling the flow of working fluid into and out of the expander, and also preferably includes a shunt line connecting an expansion chamber of the expander to a buffer chamber of the expander for minimizing pressure variations in the fluidic circuit of the engine. The engine is especially designed to operate with very high temperature input to the expander and very low temperature input to the compressor, to produce very high thermal conversion efficiency.

  19. Concise dictionary of engineering a guide to the language of engineering

    CERN Document Server

    Hanifan, Ron

    2014-01-01

    This reference defines the principle and most commonly used terms found in engineering documents and drawings across multiple disciplines and explains them in plain, unambiguous English. Concise Dictionary of Engineering: A Guide to the Language of Engineering also distinguishes how some terms take on different meanings in different engineering contexts—critical knowledge when working on collaborative projects with diverse elements and colleagues. Based on an edition developed for researchers and technicians at Lockheed Martin, each entry in this volume is written in clear, everyday English without confusing jargon and “techno-speak.” The book is ideal for students, professional engineers, industrial personnel, managers, and anyone else who requires a solid understanding of the language of engineers. This dictionary also: ·         Clarifies technical terms often intermixed or misused ·         Spans a range of engineering disciplines, including mechanical, electrical, materials, and c...

  20. Engineering success: Undergraduate Latina women's persistence in an undergradute engineering program

    Science.gov (United States)

    Rosbottom, Steven R.

    The purpose and focus of this narrative inquiry case study were to explore the personal stories of four undergraduate Latina students who persist in their engineering programs. This study was guided by two overarching research questions: a) What are the lived experiences of undergraduate Latina engineering students? b) What are the contributing factors that influence undergraduate Latina students to persist in an undergraduate engineering program? Yosso's (2005) community cultural wealth was used to the analyze data. Findings suggest through Yosso's (2005) aspirational capital, familial capital, social capital, navigational capital, and resistant capital the Latina student persisted in their engineering programs. These contributing factors brought to light five themes that emerged, the discovery of academic passions, guidance and support of family and teachers, preparation for and commitment to persistence, the power of community and collective engagement, and commitment to helping others. The themes supported their persistence in their engineering programs. Thus, this study informs policies, practices, and programs that support undergraduate Latina engineering student's persistence in engineering programs.

  1. Perspectives on Oral Communication Skills for Engineers in Engineering Profession of Pakistan

    OpenAIRE

    Inayatullah Kakepoto; Noor Abidah Mohd Omar; Yusuf Boon; S M Zafar Iqbal

    2012-01-01

    Communication plays paramount role for engineers to perform workplace jobs effectively in this modern age of industrialization. The purpose of this research paper was to determine importance of oral communication for engineers at workplace. Thirty engineers from 2 engineering organizations participated in this study. Purposive sampling method was used for data collection since respondents were drawn on specific criteria of engineers with minimum 5 years work experience. Quantitative survey ba...

  2. Alvar engine. An engine with variable compression ratio. Experiments and tests

    Energy Technology Data Exchange (ETDEWEB)

    Erlandsson, Olof

    1998-09-01

    This report is focused on tests with Variable Compression Ratio (VCR) engines, according to the Alvar engine principle. Variable compression ratio means an engine design where it is possible to change the nominal compression ratio. The purpose is to increase the fuel efficiency at part load by increasing the compression ratio. At maximum load, and maybe supercharging with for example turbocharger, it is not possible to keep a high compression ratio because of the knock phenomena. Knock is a shock wave caused by self-ignition of the fuel-air mix. If knock occurs, the engine will be exposed to a destructive load. Because of the reasons mentioned it would be an advantage if it would be possible to change the compression ratio continuously when the load changes. The Alvar engine provides a solution for variable compression ratio based on well-known engine components. This paper provides information about efficiency and emission characteristics from tests with two Alvar engines. Results from tests with a phase shift mechanism (for automatic compression ratio control) for the Alvar engine are also reviewed Examination paper. 5 refs, 23 figs, 2 tabs, 5 appendices

  3. Engineered phages for electronics.

    Science.gov (United States)

    Cui, Yue

    2016-11-15

    Phages are traditionally widely studied in biology and chemistry. In recent years, engineered phages have attracted significant attentions for functionalization or construction of electronic devices, due to their specific binding, catalytic, nucleating or electronic properties. To apply the engineered phages in electronics, these are a number of interesting questions: how to engineer phages for electronics? How are the engineered phages characterized? How to assemble materials with engineered phages? How are the engineered phages micro or nanopatterned? What are the strategies to construct electronics devices with engineered phages? This review will highlight the early attempts to address these questions and explore the fundamental and practical aspects of engineered phages in electronics, including the approaches for selection or expression of specific peptides on phage coat proteins, characterization of engineered phages in electronics, assembly of electronic materials, patterning of engineered phages, and construction of electronic devices. It provides the methodologies and opens up ex-cit-ing op-por-tu-ni-ties for the development of a variety of new electronic materials and devices based on engineered phages for future applications. Copyright © 2016 Elsevier B.V. All rights reserved.

  4. Stirling engine application study

    Science.gov (United States)

    Teagan, W. P.; Cunningham, D.

    1983-01-01

    A range of potential applications for Stirling engines in the power range from 0.5 to 5000 hp is surveyed. Over one hundred such engine applications are grouped into a small number of classes (10), with the application in each class having a high degree of commonality in technical performance and cost requirements. A review of conventional engines (usually spark ignition or Diesel) was then undertaken to determine the degree to which commercial engine practice now serves the needs of the application classes and to detemine the nature of the competition faced by a new engine system. In each application class the Stirling engine was compared to the conventional engines, assuming that objectives of ongoing Stirling engine development programs are met. This ranking process indicated that Stirling engines showed potential for use in all application classes except very light duty applications (lawn mowers, etc.). However, this potential is contingent on demonstrating much greater operating life and reliability than has been demonstrated to date by developmental Stirling engine systems. This implies that future program initiatives in developing Stirling engine systems should give more emphasis to life and reliability issues than has been the case in ongoing programs.

  5. 78 FR 64394 - Airworthiness Directives; Lycoming Engines and Continental Motors, Inc. Reciprocating Engines

    Science.gov (United States)

    2013-10-29

    ... turbine wheel failure, reduction or complete loss of engine power, loss of engine oil, oil fire, and... after receipt. FOR FURTHER INFORMATION CONTACT: Christopher Richards, Aerospace Engineer, Chicago... failure, reduction or complete loss of engine power, loss of engine oil, oil fire, and damage to the...

  6. Engineering education research in European Journal of Engineering Education and Journal of Engineering Education: citation and reference discipline analysis

    Science.gov (United States)

    Wankat, Phillip C.; Williams, Bill; Neto, Pedro

    2014-01-01

    The authors, citations and content of European Journal of Engineering Education (EJEE) and Journal of Engineering Education (JEE) in 1973 (JEE, 1975 EJEE), 1983, 1993, 2003, and available 2013 issues were analysed. Both journals transitioned from house organs to become engineering education research (EER) journals, although JEE transitioned first. In this process the number of citations rose, particularly of education and psychology sources; the percentage of research articles increased markedly as did the number of reference disciplines. The number of papers per issue, the number of single author papers, and the citations of science and engineering sources decreased. EJEE has a very broad geographic spread of authors while JEE authors are mainly US based. A 'silo' mentality where general engineering education researchers do not communicate with EER researchers in different engineering disciplines is evident. There is some danger that EER may develop into a silo that does not communicate with technically oriented engineering professors.

  7. Human engineering

    International Nuclear Information System (INIS)

    Yang, Seong Hwan; Park, Bum; Gang, Yeong Sik; Gal, Won Mo; Baek, Seung Ryeol; Choe, Jeong Hwa; Kim, Dae Sung

    2006-07-01

    This book mentions human engineering, which deals with introduction of human engineering, Man-Machine system like system design, and analysis and evaluation of Man-Machine system, data processing and data input, display, system control of man, human mistake and reliability, human measurement and design of working place, human working, hand tool and manual material handling, condition of working circumstance, working management, working analysis, motion analysis working measurement, and working improvement and design in human engineering.

  8. Educating the engineers of 2020: An outcomes-based typology of engineering undergraduates

    Science.gov (United States)

    Knight, David B.

    Members of government and industry have called for greater emphasis within U.S. colleges and universities on producing engineers who can enter and advance a more competitive, globally connected workforce. Looking toward this future, engineers will need to exhibit strong analytical skills as in the past, but they also will need to be proficient in a cadre of new abilities to compete. This study examines, in combination, an array of knowledge and skills aligned with the National Academy of Engineering's "engineer of 2020." The study has two major goals. The first is to develop a typology of engineering students based on the learning outcomes associated with the engineer of E2020. The second is to understand the educational experiences that distinguish these groups of students who resemble, more or less, the engineer of 2020. This approach acknowledges that engineering graduates need a complex skill set to succeed in the new global economy; it is the combination of skills associated with the engineer of 2020, not the individual skills in isolation, which will ensure graduates can respond to workforce needs of the future. To date, research on student outcomes has studied learning outcomes independent of one another rather than investigating student learning holistically. The study uses student data from the Prototype to production: Processes and conditions for preparing the Engineer of 2020 study, sponsored by the National Science Foundation (NSF EEC-0550608). Engineering students from a nationally representative sample of engineering programs in the United States answered a survey that collected information on their pre-college academic preparation and sociodemographic characteristics, their curricular and co-curricular experiences in their engineering programs, and their self-ratings of their engineering-related competencies. Only data on engineering students in their senior year (n=2,422) were utilized in analyses. Analyses were conducted in multiple phases for each

  9. LOW-ENGINE-FRICTION TECHNOLOGY FOR ADVANCED NATURAL-GAS RECIPROCATING ENGINES

    Energy Technology Data Exchange (ETDEWEB)

    Victor Wong; Tian Tian; Luke Moughon; Rosalind Takata; Jeffrey Jocsak

    2006-03-31

    This program aims at improving the efficiency of advanced natural-gas reciprocating engines (ANGRE) by reducing piston and piston ring assembly friction without major adverse effects on engine performance, such as increased oil consumption and wear. An iterative process of simulation, experimentation and analysis is being followed towards achieving the goal of demonstrating a complete optimized low-friction engine system. To date, a detailed set of piston and piston-ring dynamic and friction models have been developed and applied that illustrate the fundamental relationships among mechanical, surface/material and lubricant design parameters and friction losses. Demonstration of low-friction ring-pack designs in the Waukesha VGF 18GL engine confirmed total engine FEMP (friction mean effective pressure) reduction of 7-10% from the baseline configuration without significantly increasing oil consumption or blow-by flow. This represents a substantial (30-40%) reduction of the ringpack friction alone. The measured FMEP reductions were in good agreement with the model predictions. Further improvements via piston, lubricant, and surface designs offer additional opportunities. Tests of low-friction lubricants are in progress and preliminary results are very promising. The combined analysis of lubricant and surface design indicates that low-viscosity lubricants can be very effective in reducing friction, subject to component wear for extremely thin oils, which can be mitigated with further lubricant formulation and/or engineered surfaces. Hence a combined approach of lubricant design and appropriate wear reduction offers improved potential for minimum engine friction loss. Piston friction studies indicate that a flatter piston with a more flexible skirt, together with optimizing the waviness and film thickness on the piston skirt offer significant friction reduction. Combined with low-friction ring-pack, material and lubricant parameters, a total power cylinder friction

  10. 77 FR 72203 - Airworthiness Directives; Lycoming Engines and Continental Motors, Inc. Reciprocating Engines

    Science.gov (United States)

    2012-12-05

    ..., reduction or complete loss of engine power, loss of engine oil, oil fire, and damage to the airplane. DATES... after receipt. FOR FURTHER INFORMATION CONTACT: Christopher Richards, Aerospace Engineer, Chicago... wheel failure, reduction or complete loss of engine power, loss of engine oil, oil fire, and damage to...

  11. Biosystems Engineering in Portugal

    OpenAIRE

    Marques da Silva, José Rafael; Silva, Luis Leopoldo; Cruz, Vasco Fitas

    2008-01-01

    The paper gives the definition of Biosystems Engineering in Portugal; Possible revisions of the core curriculum presented in the FEANI report; the current situation of Biosystems Engineering in Portugal; The impacts of the transition to Biosystems Engineering; The need for a transition to Biosystems Engineering;Opportunities to the Biosystems Engineer in the labour market.

  12. Introducing Model-Based System Engineering Transforming System Engineering through Model-Based Systems Engineering

    Science.gov (United States)

    2014-03-31

    Web  Presentation...Software  .....................................................  20   Figure  6.  Published   Web  Page  from  Data  Collection...the  term  Model  Based  Engineering  (MBE),  Model  Driven  Engineering  ( MDE ),  or  Model-­‐Based  Systems  

  13. Solar-Thermal Engine Testing

    Science.gov (United States)

    Tucker, Stephen; Salvail, Pat; Haynes, Davy (Technical Monitor)

    2001-01-01

    A solar-thermal engine serves as a high-temperature solar-radiation absorber, heat exchanger, and rocket nozzle. collecting concentrated solar radiation into an absorber cavity and transferring this energy to a propellant as heat. Propellant gas can be heated to temperatures approaching 4,500 F and expanded in a rocket nozzle, creating low thrust with a high specific impulse (I(sub sp)). The Shooting Star Experiment (SSE) solar-thermal engine is made of 100 percent chemical vapor deposited (CVD) rhenium. The engine 'module' consists of an engine assembly, propellant feedline, engine support structure, thermal insulation, and instrumentation. Engine thermal performance tests consist of a series of high-temperature thermal cycles intended to characterize the propulsive performance of the engines and the thermal effectiveness of the engine support structure and insulation system. A silicone-carbide electrical resistance heater, placed inside the inner shell, substitutes for solar radiation and heats the engine. Although the preferred propellant is hydrogen, the propellant used in these tests is gaseous nitrogen. Because rhenium oxidizes at elevated temperatures, the tests are performed in a vacuum chamber. Test data will include transient and steady state temperatures on selected engine surfaces, propellant pressures and flow rates, and engine thrust levels. The engine propellant-feed system is designed to Supply GN2 to the engine at a constant inlet pressure of 60 psia, producing a near-constant thrust of 1.0 lb. Gaseous hydrogen will be used in subsequent tests. The propellant flow rate decreases with increasing propellant temperature, while maintaining constant thrust, increasing engine I(sub sp). In conjunction with analytical models of the heat exchanger, the temperature data will provide insight into the effectiveness of the insulation system, the structural support system, and the overall engine performance. These tests also provide experience on operational

  14. Understanding Engineering Ethics

    Directory of Open Access Journals (Sweden)

    Abdi O. Shuriye

    2012-01-01

    Full Text Available Engineering ethics aims to enhance engineer’s ability to confront moral issues raised by engineering activities. It covers engineering as social experimentation, the engineer’s responsibility for safety, and the rights of engineers. What constitutes engineering ethics is the underlining question of this research. Hence, the objective of the research is to systematically provide answers to the aforementioned question. The research also studies the scope and the origin of the subject matter. At the same time, the research highlights the significance of the subject from diverse perspectives; including Western and Islamic perspectives. ABSTRAK: Etika kejuruteraan bertujuan meningkatkan keupayaan juruera menghadapi isu-isu moralyang timbul dari aktiviti-aktiviti kejuruteraan. Ia merangkumi kejuruteraan sebagai eksperimentasi sosial, tanggungjawab jurutera terhadap keselamatan dan hak-hak jurutera. Persoalan utama penyelidikan ini adalah apa yang merangkumi etika kejuruteraan. Penyelidikan ini juga mengkaji skop dan asal usul etika kejuruteraan. Kajian ini turut membincangkan subjek kajian dari pelbagai perspektif, Barat dan Islam.KEYWORDS: engineering ethics; engineer; akhlaq; values; confidentiality; corruption; conflict of interest; whistle-blowing

  15. Practical electrical engineering

    CERN Document Server

    N Makarov, Sergey; Bitar, Stephen J

    2016-01-01

    This textbook provides comprehensive, in-depth coverage of the fundamental concepts of electrical and computer engineering. It is written from an engineering perspective, with special emphasis on circuit functionality and applications. Reliance on higher-level mathematics and physics, or theoretical proofs has been intentionally limited in order to prioritize the practical aspects of electrical engineering. This text is therefore suitable for a number of introductory circuit courses for other majors such as robotics, mechanical, biomedical, aerospace, civil, architecture, petroleum, and industrial engineering. The authors’ primary goal is to teach the aspiring engineering student all fundamental tools needed to understand, analyze and design a wide range of practical circuits and systems. Their secondary goal is to provide a comprehensive reference, for both major and non-major students as well as practicing engineers. Provides a self-contained, fundamental textbook on electric circuits and basic electronic...

  16. Milestones in Software Engineering and Knowledge Engineering History: A Comparative Review

    Science.gov (United States)

    del Águila, Isabel M.; Palma, José; Túnez, Samuel

    2014-01-01

    We present a review of the historical evolution of software engineering, intertwining it with the history of knowledge engineering because “those who cannot remember the past are condemned to repeat it.” This retrospective represents a further step forward to understanding the current state of both types of engineerings; history has also positive experiences; some of them we would like to remember and to repeat. Two types of engineerings had parallel and divergent evolutions but following a similar pattern. We also define a set of milestones that represent a convergence or divergence of the software development methodologies. These milestones do not appear at the same time in software engineering and knowledge engineering, so lessons learned in one discipline can help in the evolution of the other one. PMID:24624046

  17. Mechanical engineering education

    CERN Document Server

    Davim, J Paulo

    2012-01-01

    Mechanical Engineering is defined nowadays as a discipline "which involves the application of principles of physics, design, manufacturing and maintenance of mechanical systems". Recently, mechanical engineering has also focused on some cutting-edge subjects such as nanomechanics and nanotechnology, mechatronics and robotics, computational mechanics, biomechanics, alternative energies, as well as aspects related to sustainable mechanical engineering.This book covers mechanical engineering higher education with a particular emphasis on quality assurance and the improvement of academic

  18. Computer Engineers.

    Science.gov (United States)

    Moncarz, Roger

    2000-01-01

    Looks at computer engineers and describes their job, employment outlook, earnings, and training and qualifications. Provides a list of resources related to computer engineering careers and the computer industry. (JOW)

  19. Engineering _ litteraturliste

    DEFF Research Database (Denmark)

    Sillasen, Martin Krabbe; Daugbjerg, Peer; Nielsen, Keld

    2017-01-01

    Litteraturliste udarbejdet som grundlag for artiklen ”Engineering – svaret på naturfagenes udfordringer?”......Litteraturliste udarbejdet som grundlag for artiklen ”Engineering – svaret på naturfagenes udfordringer?”...

  20. Engineering Faculty Attitudes to General Chemistry Courses in Engineering Curricula

    Science.gov (United States)

    Garip, Mehmet; Erdil, Erzat; Bilsel, Ayhan

    2006-01-01

    A survey on the attitudes of engineering faculty to chemistry, physics, and mathematics was conducted with the aim of clarifying the attitudes of engineering faculty to chemistry courses in relation to engineering education or curricula and assessing their expectations. The results confirm that on the whole chemistry is perceived as having a…

  1. Diesel engines vs. spark ignition gasoline engines -- Which is ``greener``?

    Energy Technology Data Exchange (ETDEWEB)

    Fairbanks, J.W. [Dept. of Energy, Washington, DC (United States)

    1997-12-31

    Criteria emissions, i.e., NO{sub x}, PM, CO, CO{sub 2}, and H{sub 2}, from recently manufactured automobiles, compared on the basis of what actually comes out of the engines, the diesel engine is greener than spark ignition gasoline engines and this advantage for the diesel engine increases with time. SI gasoline engines tend to get out of tune more than diesel engines and 3-way catalytic converters and oxygen sensors degrade with use. Highway measurements of NO{sub 2}, H{sub 2}, and CO revealed that for each model year, 10% of the vehicles produce 50% of the emissions and older model years emit more than recent model year vehicles. Since 1974, cars with SI gasoline engines have uncontrolled emission until the 3-way catalytic converter reaches operating temperature, which occurs after roughly 7 miles of driving. Honda reports a system to be introduced in 1998 that will alleviate this cold start problem by storing the emissions then sending them through the catalytic converter after it reaches operating temperature. Acceleration enrichment, wherein considerable excess fuel is introduced to keep temperatures down of SI gasoline engine in-cylinder components and catalytic converters so these parts meet warranty, results in 2,500 times more CO and 40 times more H{sub 2} being emitted. One cannot kill oneself, accidentally or otherwise, with CO from a diesel engine vehicle in a confined space. There are 2,850 deaths per year attributable to CO from SI gasoline engine cars. Diesel fuel has advantages compared with gasoline. Refinery emissions are lower as catalytic cracking isn`t necessary. The low volatility of diesel fuel results in a much lower probability of fires. Emissions could be improved by further reducing sulfur and aromatics and/or fuel additives. Reformulated fuel has become the term covering reducing the fuels contribution to emissions. Further PM reduction should be anticipated with reformulated diesel and gasoline fuels.

  2. Meta Search Engines.

    Science.gov (United States)

    Garman, Nancy

    1999-01-01

    Describes common options and features to consider in evaluating which meta search engine will best meet a searcher's needs. Discusses number and names of engines searched; other sources and specialty engines; search queries; other search options; and results options. (AEF)

  3. Engine and method for operating an engine

    Science.gov (United States)

    Lauper, Jr., John Christian; Willi, Martin Leo [Dunlap, IL; Thirunavukarasu, Balamurugesh [Peoria, IL; Gong, Weidong [Dunlap, IL

    2008-12-23

    A method of operating an engine is provided. The method may include supplying a combustible combination of reactants to a combustion chamber of the engine, which may include supplying a first hydrocarbon fuel, hydrogen fuel, and a second hydrocarbon fuel to the combustion chamber. Supplying the second hydrocarbon fuel to the combustion chamber may include at least one of supplying at least a portion of the second hydrocarbon fuel from an outlet port that discharges into an intake system of the engine and supplying at least a portion of the second hydrocarbon fuel from an outlet port that discharges into the combustion chamber. Additionally, the method may include combusting the combustible combination of reactants in the combustion chamber.

  4. Culture in Engineering Education

    DEFF Research Database (Denmark)

    Hoffmann, Birgitte; Jørgensen, Ulrik; Christensen, Hans Peter

    2011-01-01

    As engineers today often work in intercultural projects and contexts, intercultural competences must be part of the learning objectives in engineering educations. Cultural aspects of engineering education should not just be treated as a question of appropriate communication and teaching: cultural...... aspects are basically part of engineering discipli¬nes, work challenges as well as the contextual elements in engineering curriculum [1,2]. This is reflected in the aims of the CDIO programme [3,4]; however, the programme, as well as the teaching practises, undoubtedly needs to further develop approaches...... to cultural aspects in engineering education. Hence the key-question of this paper is how CDIO support the development of intercultural competences in engineering education. The paper explores the implementation of CDIO in an intercultural arctic engineering programme in Greenland that since 2001 has been...

  5. NASA systems engineering handbook

    Science.gov (United States)

    Shishko, Robert; Aster, Robert; Chamberlain, Robert G.; McDuffee, Patrick; Pieniazek, Les; Rowell, Tom; Bain, Beth; Cox, Renee I.; Mooz, Harold; Polaski, Lou

    1995-06-01

    This handbook brings the fundamental concepts and techniques of systems engineering to NASA personnel in a way that recognizes the nature of NASA systems and environment. It is intended to accompany formal NASA training courses on systems engineering and project management when appropriate, and is designed to be a top-level overview. The concepts were drawn from NASA field center handbooks, NMI's/NHB's, the work of the NASA-wide Systems Engineering Working Group and the Systems Engineering Process Improvement Task team, several non-NASA textbooks and guides, and material from independent systems engineering courses taught to NASA personnel. Five core chapters cover systems engineering fundamentals, the NASA Project Cycle, management issues in systems engineering, systems analysis and modeling, and specialty engineering integration. It is not intended as a directive.

  6. Software engineering

    CERN Document Server

    Sommerville, Ian

    2010-01-01

    The ninth edition of Software Engineering presents a broad perspective of software engineering, focusing on the processes and techniques fundamental to the creation of reliable, software systems. Increased coverage of agile methods and software reuse, along with coverage of 'traditional' plan-driven software engineering, gives readers the most up-to-date view of the field currently available. Practical case studies, a full set of easy-to-access supplements, and extensive web resources make teaching the course easier than ever.

  7. Engineering Electromagnetics

    International Nuclear Information System (INIS)

    Kim, Se Yun

    2009-01-01

    This book deals with engineering electromagnetics. It contains seven chapters, which treats understanding of engineering electromagnetics such as magnet and electron spin, current and a magnetic field and an electromagnetic wave, Essential tool for engineering electromagnetics on rector and scalar, rectangular coordinate system and curl vector, electrostatic field with coulomb rule and method of electric images, Biot-Savart law, Ampere law and magnetic force, Maxwell equation and an electromagnetic wave and reflection and penetration of electromagnetic plane wave.

  8. Electrochemical energy engineering: a new frontier of chemical engineering innovation.

    Science.gov (United States)

    Gu, Shuang; Xu, Bingjun; Yan, Yushan

    2014-01-01

    One of the grand challenges facing humanity today is a safe, clean, and sustainable energy system where combustion no longer dominates. This review proposes that electrochemical energy conversion could set the foundation for such an energy system. It further suggests that a simple switch from an acid to a base membrane coupled with innovative cell designs may lead to a new era of affordable electrochemical devices, including fuel cells, electrolyzers, solar hydrogen generators, and redox flow batteries, for which recent progress is discussed using the authors' work as examples. It also notes that electrochemical energy engineering will likely become a vibrant subdiscipline of chemical engineering and a fertile ground for chemical engineering innovation. To realize this vision, it is necessary to incorporate fundamental electrochemistry and electrochemical engineering principles into the chemical engineering curriculum.

  9. Engineering the just war: examination of an approach to teaching engineering ethics.

    Science.gov (United States)

    Haws, David R

    2006-04-01

    The efficiency of engineering applied to civilian projects sometimes threatens to run away with the social agenda, but in military applications, engineering often adds a devastating sleekness to the inevitable destruction of life. The relative crudeness of terrorism (e.g., 9/11) leaves a stark after-image, which belies the comparative insignificance of random (as opposed to orchestrated) belligerence. Just as engineering dwarfs the bricolage of vernacular design 'moving us past the appreciation of brush-strokes, so to speak' the scale of engineered destruction makes it difficult to focus on the charred remains of individual lives. Engineers need to guard against the inappropriate military subsumption of their effort. Fortunately, the ethics of warfare has been an ongoing topic of discussion for millennia. This paper will examine the university core class I've developed (The Moral Dimensions of Technology) to meet accreditation requirements in engineering ethics, and the discussion with engineering and non-engineering students focused by the life of electrical engineer Vannevar Bush, with selected readings in moral philosophy from the Dao de Jing, Lao Tze, Cicero, Aurelius Augustinus, Kant, Annette Baier, Peter Singer, Elizabeth Anscombe, Philippa Foot, and Judith Thomson.

  10. Fuel Saving Strategy in Spark Ignition Engine Using Fuzzy Logic Engine Torque Control

    OpenAIRE

    Aris Triwiyatno; Sumardi

    2012-01-01

    In the case of injection gasoline engine, or better known as spark ignition engines, an effort to improve engine performance as well as to reduce fuel consumption is a fairly complex problem. Generally, engine performance improvement efforts will lead to increase in fuel consumption. However, this problem can be solved by implementing engine torque control based on intelligent regulation such as the fuzzy logic inference system. In this study, fuzzy logic engine torque regulation is used to c...

  11. Software Engineering Laboratory Series: Collected Software Engineering Papers. Volume 14

    Science.gov (United States)

    1996-01-01

    The Software Engineering Laboratory (SEL) is an organization sponsored by NASA/GSFC and created to investigate the effectiveness of software engineering technologies when applied to the development of application software. The activities, findings, and recommendations of the SEL are recorded in the Software Engineering Laboratory Series, a continuing series of reports that includes this document.

  12. Software Engineering Laboratory Series: Collected Software Engineering Papers. Volume 15

    Science.gov (United States)

    1997-01-01

    The Software Engineering Laboratory (SEL) is an organization sponsored by NASA/GSFC and created to investigate the effectiveness of software engineering technologies when applied to the development of application software. The activities, findings, and recommendations of the SEL are recorded in the Software Engineering Laboratory Series, a continuing series of reports that includes this document.

  13. Software Engineering Laboratory Series: Collected Software Engineering Papers. Volume 13

    Science.gov (United States)

    1995-01-01

    The Software Engineering Laboratory (SEL) is an organization sponsored by NASA/GSFC and created to investigate the effectiveness of software engineering technologies when applied to the development of application software. The activities, findings, and recommendations of the SEL are recorded in the Software Engineering Laboratory Series, a continuing series of reports that includes this document.

  14. Impact of an Engineering Case Study in a High School Pre-Engineering Course

    Science.gov (United States)

    Rutz, Eugene; Shafer, Michelle

    2011-01-01

    Students at an all-girls high school who were enrolled in an introduction to engineering course were presented an engineering case study to determine if the case study affected their attitudes toward engineering and their abilities to solve engineering problems. A case study on power plants was implemented during a unit on electrical engineering.…

  15. Metabolic Engineering X Conference

    Energy Technology Data Exchange (ETDEWEB)

    Flach, Evan [American Institute of Chemical Engineers

    2015-05-07

    The International Metabolic Engineering Society (IMES) and the Society for Biological Engineering (SBE), both technological communities of the American Institute of Chemical Engineers (AIChE), hosted the Metabolic Engineering X Conference (ME-X) on June 15-19, 2014 at the Westin Bayshore in Vancouver, British Columbia. It attracted 395 metabolic engineers from academia, industry and government from around the globe.

  16. Small Engines as Bottoming Cycle Steam Expanders for Internal Combustion Engines

    Directory of Open Access Journals (Sweden)

    Rohitha Weerasinghe

    2017-01-01

    Full Text Available Heat recovery bottoming cycles for internal combustion engines have opened new avenues for research into small steam expanders (Stobart and Weerasinghe, 2006. Dependable data for small steam expanders will allow us to predict their suitability as bottoming cycle engines and the fuel economy achieved by using them as bottoming cycles. Present paper is based on results of experiments carried out on small scale Wankel and two-stroke reciprocating engines as air expanders and as steam expanders. A test facility developed at Sussex used for measurements is comprised of a torque, power and speed measurements, electronic actuation of valves, synchronized data acquisition of pressure, and temperatures of steam and inside of the engines for steam and internal combustion cycles. Results are presented for four engine modes, namely, reciprocating engine in uniflow steam expansion mode and air expansion mode and rotary Wankel engine in steam expansion mode and air expansion mode. The air tests will provide base data for friction and motoring effects whereas steam tests will tell how effective the engines will be in this mode. Results for power, torque, and p-V diagrams are compared to determine the change in performance from air expansion mode to steam expansion mode.

  17. Engineering Task Plan for Routine Engineering Support for Core Sampler System

    International Nuclear Information System (INIS)

    BOGER, R.M.

    1999-01-01

    Routine engineering support is required during normal operation of the core sampler trucks and associated ancillary equipment. This engineering support consists of, but is not limited to, troubleshooting operation problems, correcting minor design problems, assistance with work package preparation, assistance with procurement, fabrication shop support, planning of engineering tasks and preparation of associated Engineering Task Plans (ETP) and Engineering Service Requests (ESR). This ETP is the management plan document for implementing routine engineering support. Any additional changes to the scope of this ETP shall require a Letter of Instruction from Lockheed Martin Hanford Corp (LMHC). This document will also be the Work Planning Document for Development Control (HNF 1999a). The scope of this task will be to provide routine engineering support for Characterization equipment as required to support Characterization Operations. A task by task decision will be made by management to determine which tasks will be done per this ETP and if additional ETPs and/or ESRs are required. Due to the unique nature of this task, the only identifiable deliverable is to provide support as requested. Deliverables will be recorded in a task logbook as activities are identified. ESRs will be generated for tasks that require more than 40 person hours to complete, per Characterization Engineering Desk Instructions (DI 1999a)

  18. Identification of pink-pigmented bacteria isolated from environmental water samples and their biofilm formation abilities.

    Science.gov (United States)

    Furuhata, Katsunori; Kato, Yuko; Goto, Keiichi; Saitou, Keiko; Sugiyama, Jun-Ichi; Hara, Motonobu; Fukuyama, Masahumi

    2008-06-01

    Sixty-seven strains of pink-pigmented bacteria, which were isolated from environmental water samples collected nationwide, were identified by partial 16S rDNA sequence analysis. In addition, the biofilm formation ability of the isolates was experimentally investigated. We could identify only 2 strains at the species level: Pedobacter roseus HS-38 and Runella slithyformis HS-77. The results showed that of the strains tested, 22 strains (32.8%) were Pedobacter spp., which was most frequently identified, followed by 19 strains (28.4%) of Arcicella spp., 16 strains (23.9%) of Deinococcus spp., 5 strains (7.5%) of Roseomonas spp., 4 strains (6.0%) of Flectobacillus spp. and 1 strain (1.5%) of Runella sp. Most isolates showed low similarity values to previously known species, and they were found to be novel species. At a result, it was difficult to identify environmental water-derived pink-pigmented bacteria at the species level. On the other hand, when we measured the absorbance by the crystal violet staining to examine the quantities of biofilm formation of these strains, fifty-five (82.0%) of the 67 isolates formed biofilm. The absorbance of Deinococcus sp. HS-75 was the highest (3.56). When comparing the absorbance values among the genera, Roseomonas spp. showed the highest absorbance (mean:1.62), followed by Deinococcus spp. (mean: 1.03), and Arcicella spp. (mean: 1.01). Strains of Flectobacillus spp. (mean: 0.48) and Pedobacter spp. (mean: 0.42) showed lower absorbance values. As above, it was shown that, at the species level, the pink-pigmented bacteria in the water in the Japanese environment had various levels of ability to form biofilm.

  19. Engineering Complex Tissues

    Science.gov (United States)

    MIKOS, ANTONIOS G.; HERRING, SUSAN W.; OCHAREON, PANNEE; ELISSEEFF, JENNIFER; LU, HELEN H.; KANDEL, RITA; SCHOEN, FREDERICK J.; TONER, MEHMET; MOONEY, DAVID; ATALA, ANTHONY; VAN DYKE, MARK E.; KAPLAN, DAVID; VUNJAK-NOVAKOVIC, GORDANA

    2010-01-01

    This article summarizes the views expressed at the third session of the workshop “Tissue Engineering—The Next Generation,” which was devoted to the engineering of complex tissue structures. Antonios Mikos described the engineering of complex oral and craniofacial tissues as a “guided interplay” between biomaterial scaffolds, growth factors, and local cell populations toward the restoration of the original architecture and function of complex tissues. Susan Herring, reviewing osteogenesis and vasculogenesis, explained that the vascular arrangement precedes and dictates the architecture of the new bone, and proposed that engineering of osseous tissues might benefit from preconstruction of an appropriate vasculature. Jennifer Elisseeff explored the formation of complex tissue structures based on the example of stratified cartilage engineered using stem cells and hydrogels. Helen Lu discussed engineering of tissue interfaces, a problem critical for biological fixation of tendons and ligaments, and the development of a new generation of fixation devices. Rita Kandel discussed the challenges related to the re-creation of the cartilage-bone interface, in the context of tissue engineered joint repair. Frederick Schoen emphasized, in the context of heart valve engineering, the need for including the requirements derived from “adult biology” of tissue remodeling and establishing reliable early predictors of success or failure of tissue engineered implants. Mehmet Toner presented a review of biopreservation techniques and stressed that a new breakthrough in this field may be necessary to meet all the needs of tissue engineering. David Mooney described systems providing temporal and spatial regulation of growth factor availability, which may find utility in virtually all tissue engineering and regeneration applications, including directed in vitro and in vivo vascularization of tissues. Anthony Atala offered a clinician’s perspective for functional tissue

  20. 76 FR 82202 - Airworthiness Directives; International Aero Engines AG Turbofan Engines

    Science.gov (United States)

    2011-12-30

    ... Engines AG Turbofan Engines AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Notice of proposed... International Aero Engines AG (IAE) V2500-A1, V2525-D5 and V2528-D5 turbofan engines, and certain serial numbers (S/Ns) of IAE V2522-A5, V2524-A5, V2527-A5, V2527E-A5, V2527M-A5, V2530-A5, and V2533-A5 turbofan...

  1. Engine Torque Control of Spark Ignition Engine using Fuzzy Gain Scheduling

    OpenAIRE

    Aris Triwiyatno

    2012-01-01

    In the spark ignition engine system, driver convenience is very dependent on satisfying engine torque appropriate with the throttle position given by the driver. Unfortunately, sometimes the fulfillment of engine torque is not in line with fuel saving efforts. This requires the development of high performance and robust power train controllers. One way to potentially meet these performance requirements is to introduce a method of controlling engine torque using fuzzy gain scheduling. By using...

  2. Materials Science and Engineering |

    Science.gov (United States)

    Engineering? What Is Materials Science and Engineering? MSE combines engineering, physics and chemistry to solve problems in nanotechnology, biotechnology, information technology, energy, manufacturing, and more ,' which could replace steel. Materials Science and Mechanical Engineering Professors work together to

  3. Educating the humanitarian engineer.

    Science.gov (United States)

    Passino, Kevin M

    2009-12-01

    The creation of new technologies that serve humanity holds the potential to help end global poverty. Unfortunately, relatively little is done in engineering education to support engineers' humanitarian efforts. Here, various strategies are introduced to augment the teaching of engineering ethics with the goal of encouraging engineers to serve as effective volunteers for community service. First, codes of ethics, moral frameworks, and comparative analysis of professional service standards lay the foundation for expectations for voluntary service in the engineering profession. Second, standard coverage of global issues in engineering ethics educates humanitarian engineers about aspects of the community that influence technical design constraints encountered in practice. Sample assignments on volunteerism are provided, including a prototypical design problem that integrates community constraints into a technical design problem in a novel way. Third, it is shown how extracurricular engineering organizations can provide a theory-practice approach to education in volunteerism. Sample completed projects are described for both undergraduates and graduate students. The student organization approach is contrasted with the service-learning approach. Finally, long-term goals for establishing better infrastructure are identified for educating the humanitarian engineer in the university, and supporting life-long activities of humanitarian engineers.

  4. Fostering Creative Engineers: A Key to Face the Complexity of Engineering Practice

    Science.gov (United States)

    Zhou, Chunfang

    2012-01-01

    Recent studies have argued a shift of thinking about engineering practice from a linear conception to a system understanding. The complexity of engineering practice has been thought of as the root of challenges for engineers. Moreover, creativity has been emphasised as one key capability that engineering students should master. This paper aims to…

  5. Multi-office engineering

    International Nuclear Information System (INIS)

    Cowle, E.S.; Hall, L.D.; Koss, P.; Saheb, E.; Setrakian, V.

    1995-01-01

    This paper addresses the viability of multi-office project engineering as has been made possible in a large part by the computer age. Brief discussions are provided on two past projects describing the authors' initial efforts at multi-office engineering, and an in-depth discussion is provided on a current Bechtel project that demonstrates their multi-office engineering capabilities. Efficiencies and cost savings associated with executing an engineering project from multiple office locations was identified as a viable and cost-effective execution approach. The paper also discusses how the need for multi-office engineering came about, what is required to succeed, and where they are going from here. Furthermore, it summarizes the benefits to their clients and to Bechtel

  6. Low-Engine-Friction Technology for Advanced Natural-Gas Reciprocating Engines

    Energy Technology Data Exchange (ETDEWEB)

    Victor Wong; Tian Tian; G. Smedley; L. Moughon; Rosalind Takata; J. Jocsak

    2006-11-30

    This program aims at improving the efficiency of advanced natural-gas reciprocating engines (ANGRE) by reducing piston and piston ring assembly friction without major adverse effects on engine performance, such as increased oil consumption and wear. An iterative process of simulation, experimentation and analysis has been followed towards achieving the goal of demonstrating a complete optimized low-friction engine system. In this program, a detailed set of piston and piston-ring dynamic and friction models have been adapted and applied that illustrate the fundamental relationships among mechanical, surface/material and lubricant design parameters and friction losses. Demonstration of low-friction ring-pack designs in the Waukesha VGF 18GL engine confirmed ring-pack friction reduction of 30-40%, which translates to total engine FEMP (friction mean effective pressure) reduction of 7-10% from the baseline configuration without significantly increasing oil consumption or blow-by flow. The study on surface textures, including roughness characteristics, cross hatch patterns, dimples and grooves have shown that even relatively small-scale changes can have a large effect on ring/liner friction, in some cases reducing FMEP by as much as 30% from a smooth surface case. The measured FMEP reductions were in good agreement with the model predictions. The combined analysis of lubricant and surface design indicates that low-viscosity lubricants can be very effective in reducing friction, subject to component wear for extremely thin oils, which can be mitigated with further lubricant formulation and/or engineered surfaces. Hence a combined approach of lubricant design and appropriate wear reduction offers improved potential for minimum engine friction loss. Testing of low-friction lubricants showed that total engine FMEP reduced by up to {approx}16.5% from the commercial reference oil without significantly increasing oil consumption or blow-by flow. Piston friction studies

  7. Fostering Creative Engineers

    DEFF Research Database (Denmark)

    Zhou, Chunfang

    2012-01-01

    . As the literature demonstrates, this paper reveals the understanding of complexity in engineering practice and the roles of creativity in engineering practice. In addition, the barriers to creativity in current engineering education and some implications of pedagogic strategies will be discussed. So this paper...

  8. Service Cart For Engines

    Science.gov (United States)

    Ng, Gim Shek

    1995-01-01

    Cart supports rear-mounted air-cooled engine from Volkswagen or Porsche automobile. One person removes, repairs, tests, and reinstalls engine of car, van, or home-built airplane. Consists of framework of wood, steel, and aluminum components supported by four wheels. Engine lifted from vehicle by hydraulic jack and gently lowered onto waiting cart. Jack removed from under engine. Rear of vehicle raised just enough that engine can be rolled out from under it. Cart easily supports 200-lb engine. Also used to hold transmission. With removable sheet-metal top, cart used as portable seat.

  9. Wave Engine Topping Cycle Assessment

    Science.gov (United States)

    Welch, Gerard E.

    1996-01-01

    The performance benefits derived by topping a gas turbine engine with a wave engine are assessed. The wave engine is a wave rotor that produces shaft power by exploiting gas dynamic energy exchange and flow turning. The wave engine is added to the baseline turboshaft engine while keeping high-pressure-turbine inlet conditions, compressor pressure ratio, engine mass flow rate, and cooling flow fractions fixed. Related work has focused on topping with pressure-exchangers (i.e., wave rotors that provide pressure gain with zero net shaft power output); however, more energy can be added to a wave-engine-topped cycle leading to greater engine specific-power-enhancement The energy addition occurs at a lower pressure in the wave-engine-topped cycle; thus the specific-fuel-consumption-enhancement effected by ideal wave engine topping is slightly lower than that effected by ideal pressure-exchanger topping. At a component level, however, flow turning affords the wave engine a degree-of-freedom relative to the pressure-exchanger that enables a more efficient match with the baseline engine. In some cases, therefore, the SFC-enhancement by wave engine topping is greater than that by pressure-exchanger topping. An ideal wave-rotor-characteristic is used to identify key wave engine design parameters and to contrast the wave engine and pressure-exchanger topping approaches. An aerodynamic design procedure is described in which wave engine design-point performance levels are computed using a one-dimensional wave rotor model. Wave engines using various wave cycles are considered including two-port cycles with on-rotor combustion (valved-combustors) and reverse-flow and through-flow four-port cycles with heat addition in conventional burners. A through-flow wave cycle design with symmetric blading is used to assess engine performance benefits. The wave-engine-topped turboshaft engine produces 16% more power than does a pressure-exchanger-topped engine under the specified topping

  10. Conceptual study of advanced VTOL transport aircraft engine; Kosoku VTOL kiyo engine no gainen kento

    Energy Technology Data Exchange (ETDEWEB)

    Saito, Y; Endo, M; Matsuda, Y; Sugiyama, N; Watanabe, M; Sugahara, N; Yamamoto, K [National Aerospace Laboratory, Tokyo (Japan)

    1996-04-01

    This report proposes the concept of an ultra-low noise engine for advanced high subsonic VTOL transport aircraft, and discusses its technological feasibility. As one of the applications of the previously reported `separated core turbofan engine,` the conceptual engine is composed of 3 core engines, 2 cruise fan engines for high subsonic cruising and 6 lift fan engines producing thrust of 98kN (10000kgf)/engine. The core turbojet engine bleeds a large amount of air at the outlet of a compressor to supply driving high-pressure air for fans to other engines. The lift fan engine is composed of a lift fan, driving combustor, turbine and speed reduction gear, and is featured by not only high operation stability and thin fan engine like a separated core engine but also ultra-low noise operation. The cruise fan engine adopts the same configuration as the lift fan engine. Since this engine configuration has no technological problems difficult to be overcome, its high technological feasibility is expected. 6 refs., 7 figs., 5 tabs.

  11. Glycosylation Engineering

    DEFF Research Database (Denmark)

    Clausen, Henrik; Wandall, Hans H.; Steentoft, Catharina

    2017-01-01

    Knowledge of the cellular pathways of glycosylation across phylogeny provides opportunities for designing glycans via genetic engineering in a wide variety of cell types including bacteria, fungi, plant cells, and mammalian cells. The commercial demand for glycosylation engineering is broad......, including production of biological therapeutics with defined glycosylation (Chapter 57). This chapter describes how knowledge of glycan structures and their metabolism (Parts I–III of this book) has led to the current state of glycosylation engineering in different cell types. Perspectives for rapid...

  12. Health care engineering management.

    Science.gov (United States)

    Jarzembski, W B

    1980-01-01

    Today, health care engineering management is merely a concept of dreamers, with most engineering decisions in health care being made by nonengineers. It is the purpose of this paper to present a rationale for an integrated hospital engineering group, and to acquaint the clinical engineer with some of the salient features of management concepts. Included are general management concepts, organization, personnel management, and hospital engineering systems.

  13. Engineering Elegant Systems: Postulates, Principles, and Hypotheses of Systems Engineering

    Science.gov (United States)

    Watson, Michael D.

    2018-01-01

    Definition: System Engineering is the engineering discipline which integrates the system functions, system environment, and the engineering disciplines necessary to produce and/or operate an elegant system; Elegant System - A system that is robust in application, fully meeting specified and adumbrated intent, is well structured, and is graceful in operation. Primary Focus: System Design and Integration: Identify system couplings and interactions; Identify system uncertainties and sensitivities; Identify emergent properties; Manage the effectiveness of the system. Engineering Discipline Integration: Manage flow of information for system development and/or operations; Maintain system activities within budget and schedule. Supporting Activities: Process application and execution.

  14. Protein Engineering: Case Studies of Commercialized Engineered Products

    Science.gov (United States)

    Walsh, Gary

    2007-01-01

    Programs in biochemistry invariably encompass the principles of protein engineering. Students often display increased understanding and enthusiasm when theoretical concepts are underpinned by practical example. Herein are presented five case studies, each focusing upon a commercial protein product engineered to enhance its application-relevant…

  15. Engineering Cartilage

    Science.gov (United States)

    ... Research Matters NIH Research Matters March 3, 2014 Engineering Cartilage Artistic rendering of human stem cells on ... situations has been a major goal in tissue engineering. Cartilage contains water, collagen, proteoglycans, and chondrocytes. Collagens ...

  16. Industrial Engineering

    DEFF Research Database (Denmark)

    Karlsson, Christer

    2015-01-01

    Industrial engineering is a discipline that is concerned with increasing the effectiveness of (primarily) manufacturing and (occasionally).......Industrial engineering is a discipline that is concerned with increasing the effectiveness of (primarily) manufacturing and (occasionally)....

  17. Biomedical engineering fundamentals

    CERN Document Server

    Bronzino, Joseph D

    2014-01-01

    Known as the bible of biomedical engineering, The Biomedical Engineering Handbook, Fourth Edition, sets the standard against which all other references of this nature are measured. As such, it has served as a major resource for both skilled professionals and novices to biomedical engineering.Biomedical Engineering Fundamentals, the first volume of the handbook, presents material from respected scientists with diverse backgrounds in physiological systems, biomechanics, biomaterials, bioelectric phenomena, and neuroengineering. More than three dozen specific topics are examined, including cardia

  18. Battery systems engineering

    CERN Document Server

    Rahn, Christopher D

    2012-01-01

    A complete all-in-one reference on the important interdisciplinary topic of Battery Systems Engineering Focusing on the interdisciplinary area of battery systems engineering, this book provides the background, models, solution techniques, and systems theory that are necessary for the development of advanced battery management systems. It covers the topic from the perspective of basic electrochemistry as well as systems engineering topics and provides a basis for battery modeling for system engineering of electric and hybrid electric vehicle platforms. This original

  19. Perspectives on Oral Communication Skills for Engineers in Engineering Profession of Pakistan

    Directory of Open Access Journals (Sweden)

    Inayatullah Kakepoto

    2012-09-01

    Full Text Available Communication plays paramount role for engineers to perform workplace jobs effectively in this modern age of industrialization. The purpose of this research paper was to determine importance of oral communication for engineers at workplace. Thirty engineers from 2 engineering organizations participated in this study. Purposive sampling method was used for data collection since respondents were drawn on specific criteria of engineers with minimum 5 years work experience. Quantitative survey based on questionnaire survey was used for data collection purpose. Data were analyzed using Statistical Package for Social Sciences (SPSS 15.0. The results of the study indicated that oral communication skills such as oral presentation, participation in meetings, conversation, discussion, and negotiation skill play significant role for engineers at workplace. Thus, quantitative data analysis results indicate that oral communication skills play significant role for engineers to perform workplace jobs efficiently in this competitive work environment of organizations. However, the results of this study are consistent with other literature review findings on importance of oral communication skills for engineers at workplace.

  20. Radiological Engineering: A graduate engineering - based curriculum for radiation protection

    International Nuclear Information System (INIS)

    Kearfott, K.J.; Wepfer, W.J.

    1994-01-01

    Several U.S. universities maintain formal graduate health physics curricula within their Colleges of Engineering. The term radiological engineering was coined to describe the discipline of applying engineering principles to the radiation protection aspects of nuclear technology. Radiological engineering programmes may require a specific core group of courses such as radiation biology, radiation protection practice, nuclear physics, radiation detectors, and radiation dosimetry. Students then might specialist in environmental, nuclear facilities or medical applications areas by selecting advanced courses and graduate design or research projects. In some instances the master's degree may be completed through remotely-delivered lectures. Such programmes promise to assist in educating a new group of engineering professionals dedicated to the safe utilisation of nuclear technology. The Georgis Institute of Technology's programme will serve as the specific example for this report. 8 refs., 1 fig

  1. Tokamak engineering mechanics

    International Nuclear Information System (INIS)

    Song, Yuntao; Wu, Weiyue; Du, Shijun

    2014-01-01

    Provides a systematic introduction to tokamaks in engineering mechanics. Includes design guides based on full mechanical analysis, which makes it possible to accurately predict load capacity and temperature increases. Presents comprehensive information on important design factors involving materials. Covers the latest advances in and up-to-date references on tokamak devices. Numerous examples reinforce the understanding of concepts and provide procedures for design. Tokamak Engineering Mechanics offers concise and thorough coverage of engineering mechanics theory and application for tokamaks, and the material is reinforced by numerous examples. Chapter topics include general principles, static mechanics, dynamic mechanics, thermal fluid mechanics and multiphysics structural mechanics of tokamak structure analysis. The theoretical principle of the design and the methods of the analysis for various components and load conditions are presented, while the latest engineering technologies are also introduced. The book will provide readers involved in the study of mechanical/fusion engineering with a general understanding of tokamak engineering mechanics.

  2. Embedded engineering education

    CERN Document Server

    Kaštelan, Ivan; Temerinac, Miodrag; Barak, Moshe; Sruk, Vlado

    2016-01-01

    This book focuses on the outcome of the European research project “FP7-ICT-2011-8 / 317882: Embedded Engineering Learning Platform” E2LP. Additionally, some experiences and researches outside this project have been included. This book provides information about the achieved results of the E2LP project as well as some broader views about the embedded engineering education. It captures project results and applications, methodologies, and evaluations. It leads to the history of computer architectures, brings a touch of the future in education tools and provides a valuable resource for anyone interested in embedded engineering education concepts, experiences and material. The book contents 12 original contributions and will open a broader discussion about the necessary knowledge and appropriate learning methods for the new profile of embedded engineers. As a result, the proposed Embedded Computer Engineering Learning Platform will help to educate a sufficient number of future engineers in Europe, capable of d...

  3. April 2016 Milwaukee Engineer | College of Engineering & Applied Science

    Science.gov (United States)

    Olympiad Girls Who Code Club FIRST Tech Challenge NSF I-Corps Site of Southeastern Wisconsin UW-Milwaukee with up and coming engineering talent. Read more. merc-sm Register for the Milwaukee Engineering

  4. Mechanical Engineering Department technical review

    Energy Technology Data Exchange (ETDEWEB)

    Carr, R.B.; Abrahamson, L.; Denney, R.M.; Dubois, B.E (eds.)

    1982-01-01

    Technical achievements and publication abstracts related to research in the following Divisions of Lawrence Livermore Laboratory are reported in this biannual review: Nuclear Fuel Engineering; Nuclear Explosives Engineering; Weapons Engineering; Energy Systems Engineering; Engineering Sciences; Magnetic Fusion Engineering; and Material Fabrication. (LCL)

  5. Computational modeling for eco engineering: Making the connections between engineering and ecology (Invited)

    Science.gov (United States)

    Bowles, C.

    2013-12-01

    Ecological engineering, or eco engineering, is an emerging field in the study of integrating ecology and engineering, concerned with the design, monitoring, and construction of ecosystems. According to Mitsch (1996) 'the design of sustainable ecosystems intends to integrate human society with its natural environment for the benefit of both'. Eco engineering emerged as a new idea in the early 1960s, and the concept has seen refinement since then. As a commonly practiced field of engineering it is relatively novel. Howard Odum (1963) and others first introduced it as 'utilizing natural energy sources as the predominant input to manipulate and control environmental systems'. Mtisch and Jorgensen (1989) were the first to define eco engineering, to provide eco engineering principles and conceptual eco engineering models. Later they refined the definition and increased the number of principles. They suggested that the goals of eco engineering are: a) the restoration of ecosystems that have been substantially disturbed by human activities such as environmental pollution or land disturbance, and b) the development of new sustainable ecosystems that have both human and ecological values. Here a more detailed overview of eco engineering is provided, particularly with regard to how engineers and ecologists are utilizing multi-dimensional computational models to link ecology and engineering, resulting in increasingly successful project implementation. Descriptions are provided pertaining to 1-, 2- and 3-dimensional hydrodynamic models and their use at small- and large-scale applications. A range of conceptual models that have been developed to aid the in the creation of linkages between ecology and engineering are discussed. Finally, several case studies that link ecology and engineering via computational modeling are provided. These studies include localized stream rehabilitation, spawning gravel enhancement on a large river system, and watershed-wide floodplain modeling of

  6. Engineering Knowledge and Student Development: An Institutional and Pedagogical Critique of Engineering Education

    Science.gov (United States)

    Tang, Xiaofeng

    Educators have recommended the integration of engineering and the liberal arts as a promising educational model to prepare young engineers for global economic, environmental, sociotechnical, and ethical challenges. Drawing upon philosophy of technology, engineering studies, and educational psychology, this dissertation examines diverse visions and strategies for integrating engineering and liberal education and explores their impacts on students' intellectual and moral development. Based on archival research, interviews, and participant observation, the dissertation presents in-depth case studies of three educational initiatives that seek to blend engineering with the humanities, social sciences, and arts: Harvey Mudd College, the Picker Engineering Program at Smith College, and the Programs in Design and Innovation at Rensselaer Polytechnic Institute. The research finds that learning engineering in a liberal arts context increases students' sense of "owning" their education and contributes to their communication, teamwork, and other non-technical professional skills. In addition, opportunities for extensive liberal arts learning in the three cases encourage some students to pursue alternative, less technocentric approaches to engineering. Nevertheless, the case studies suggest that the epistemological differences between the engineering and liberal arts instructors help maintain a technical/social dualism among most students. Furthermore, the dissertation argues a "hidden curriculum," which reinforces the dominant ideology in the engineering profession, persists in the integrated programs and prevents the students from reflecting on the broad social context of engineering and critically examining the assumptions upheld in the engineering profession.

  7. Gendered Perceptions of Typical Engineers across Specialties for Engineering Majors

    Science.gov (United States)

    Kelley, Margaret S.; Bryan, Kimberley K.

    2018-01-01

    Young women do not choose to be engineers nearly as often as young men, and they tend to cluster in particular specialties when they do. We examine these patterns and the role of gender schemas as applied to perceptions of typical engineers in understanding the choices that women make in terms of engineering specialties. We use Part 1 of two waves…

  8. Engineering hydro's future

    International Nuclear Information System (INIS)

    Anderson, J.L.

    1992-01-01

    In this challenging hydropower market, hydropower engineering services are in high demand. The number of new hydropower projects entering the pipeline may have slowed in recent years but that does not mean work is not being done. Independent developers, utilities and municipalities are carrying out a considerable amount of hydropower activity. Whatever the work involves - preliminary planning, licensing and relicensing, environmental mitigation, plant rehabilitation or new-plant startup - engineering firms are finding a brisk market for their services. The complexity of the regulatory framework makes hydropower facility and other water resource work more important then ever. Executives of three engineering firms - Acres International, Harza Engineering and Black and Veatch - active in these areas discuss their views on the future of the hydropower engineering market

  9. The Case for Distributed Engine Control in Turbo-Shaft Engine Systems

    Science.gov (United States)

    Culley, Dennis E.; Paluszewski, Paul J.; Storey, William; Smith, Bert J.

    2009-01-01

    The turbo-shaft engine is an important propulsion system used to power vehicles on land, sea, and in the air. As the power plant for many high performance helicopters, the characteristics of the engine and control are critical to proper vehicle operation as well as being the main determinant to overall vehicle performance. When applied to vertical flight, important distinctions exist in the turbo-shaft engine control system due to the high degree of dynamic coupling between the engine and airframe and the affect on vehicle handling characteristics. In this study, the impact of engine control system architecture is explored relative to engine performance, weight, reliability, safety, and overall cost. Comparison of the impact of architecture on these metrics is investigated as the control system is modified from a legacy centralized structure to a more distributed configuration. A composite strawman system which is typical of turbo-shaft engines in the 1000 to 2000 hp class is described and used for comparison. The overall benefits of these changes to control system architecture are assessed. The availability of supporting technologies to achieve this evolution is also discussed.

  10. The European Engineer: A British Civil Engineering Viewpoint.

    Science.gov (United States)

    Fleming, George

    1988-01-01

    Confronts the problems of defining the European Engineer in terms of educational and practical training. Analyzes the supply and demand requirements of engineering management and practice. Compares these analyses with conditions in the United States. Gives details of the educational process in a number of European countries. (CW)

  11. Da "Search engines" a "Shop engines"

    OpenAIRE

    Lupi, Mauro

    2001-01-01

    The change occuring related to “search engines” is going towards e-commerce, transforming all the main search engines into information and commercial suggestion conveying means, basing their businnes on this activity. In a next future we will find two main series of search engines: from one side, the portals that will offer a general orientation guide being convoying means for services and to-buy products; from the other side, vertical portals able to offer information and products on specifi...

  12. Engineering students' sustainability approaches

    Science.gov (United States)

    Haase, S.

    2014-05-01

    Sustainability issues are increasingly important in engineering work all over the world. This article explores systematic differences in self-assessed competencies, interests, importance, engagement and practices of newly enrolled engineering students in Denmark in relation to environmental and non-environmental sustainability issues. The empirical base of the article is a nation-wide, web-based survey sent to all newly enrolled engineering students in Denmark commencing their education in the fall term 2010. The response rate was 46%. The survey focused on a variety of different aspects of what can be conceived as sustainability. By means of cluster analysis, three engineering student approaches to sustainability are identified and described. The article provides knowledge on the different prerequisites of engineering students in relation to the role of sustainability in engineering. This information is important input to educators trying to target new engineering students and contribute to the provision of engineers equipped to meet sustainability challenges.

  13. Biogas Production and Engine Conversion From Diesel Engine to Biogas Engine for Lighting in Rural Area

    OpenAIRE

    Tun, Seint Thandar

    2012-01-01

    The research of alternative fuels implemented in internal combustion engines are becoming the subjects of interest nowadays. This paper describes a production of biogas from cow dung, diesel engine conversion process with piston modification of ZH1115 diesel engine. To produce biogas, the usual practice is to mix water with some organic material, such as cow dung (a free source of the appropriate micro-organisms). The slurry is placed in a leak-proof container (called a digester) and leaves i...

  14. Combustion engineering

    CERN Document Server

    Ragland, Kenneth W

    2011-01-01

    Introduction to Combustion Engineering The Nature of Combustion Combustion Emissions Global Climate Change Sustainability World Energy Production Structure of the Book   Section I: Basic Concepts Fuels Gaseous Fuels Liquid Fuels Solid Fuels Problems Thermodynamics of Combustion Review of First Law Concepts Properties of Mixtures Combustion StoichiometryChemical EnergyChemical EquilibriumAdiabatic Flame TemperatureChemical Kinetics of CombustionElementary ReactionsChain ReactionsGlobal ReactionsNitric Oxide KineticsReactions at a Solid SurfaceProblemsReferences  Section II: Combustion of Gaseous and Vaporized FuelsFlamesLaminar Premixed FlamesLaminar Flame TheoryTurbulent Premixed FlamesExplosion LimitsDiffusion FlamesGas-Fired Furnaces and BoilersEnergy Balance and EfficiencyFuel SubstitutionResidential Gas BurnersIndustrial Gas BurnersUtility Gas BurnersLow Swirl Gas BurnersPremixed-Charge Engine CombustionIntroduction to the Spark Ignition EngineEngine EfficiencyOne-Zone Model of Combustion in a Piston-...

  15. Cyber-Informed Engineering

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, Robert S. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Benjamin, Jacob [Idaho National Lab. (INL), Idaho Falls, ID (United States); Wright, Virginia L. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Quinones, Luis [Idaho National Lab. (INL), Idaho Falls, ID (United States); Paz, Jonathan [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2017-03-01

    A continuing challenge for engineers who utilize digital systems is to understand the impact of cyber-attacks across the entire product and program lifecycle. This is a challenge due to the evolving nature of cyber threats that may impact the design, development, deployment, and operational phases of all systems. Cyber Informed Engineering is the process by which engineers are made aware of both how to use their engineering knowledge to positively impact the cyber security in the processes by which they architect and design components and the services and security of the components themselves.

  16. Geothermal reservoir engineering

    CERN Document Server

    Grant, Malcolm Alister

    2011-01-01

    As nations alike struggle to diversify and secure their power portfolios, geothermal energy, the essentially limitless heat emanating from the earth itself, is being harnessed at an unprecedented rate.  For the last 25 years, engineers around the world tasked with taming this raw power have used Geothermal Reservoir Engineering as both a training manual and a professional reference.  This long-awaited second edition of Geothermal Reservoir Engineering is a practical guide to the issues and tasks geothermal engineers encounter in the course of their daily jobs. The bo

  17. Cyber-Informed Engineering

    International Nuclear Information System (INIS)

    Anderson, Robert S.; Benjamin, Jacob; Wright, Virginia L.; Quinones, Luis; Paz, Jonathan

    2017-01-01

    A continuing challenge for engineers who utilize digital systems is to understand the impact of cyber-attacks across the entire product and program lifecycle. This is a challenge due to the evolving nature of cyber threats that may impact the design, development, deployment, and operational phases of all systems. Cyber Informed Engineering is the process by which engineers are made aware of both how to use their engineering knowledge to positively impact the cyber security in the processes by which they architect and design components and the services and security of the components themselves.

  18. World Congress on Engineering 2015

    CERN Document Server

    Yang, Gi-Chul; Gelman, Len

    2016-01-01

    This volume presents selected peer-reviewed, revised and extended research articles written by prominent researchers who participated in the World Congress on Engineering 2015, held in London, UK, 1-3 July, 2015. This large international conference covered advances in engineering technologies and the physical sciences, with contributions on subjects including mechanical engineering, bioengineering, internet engineering, image engineering, wireless networks, knowledge engineering, manufacturing engineering, and industrial applications. This book offers a snapshot of the state-of-the-art, highlighting tremendous advances in engineering technologies and physical sciences and their applications, and will serve as an excellent reference for researchers and graduate students working in many different disciplines of physical sciences and engineering.

  19. Hot air balloon engine

    Energy Technology Data Exchange (ETDEWEB)

    Edmonds, Ian [Solartran Pty Ltd, 12 Lentara Street, Kenmore, Brisbane 4069 (Australia)

    2009-04-15

    This paper describes a solar powered reciprocating engine based on the use of a tethered hot air balloon fuelled by hot air from a glazed collector. The basic theory of the balloon engine is derived and used to predict the performance of engines in the 10 kW to 1 MW range. The engine can operate over several thousand metres altitude with thermal efficiencies higher than 5%. The engine thermal efficiency compares favorably with the efficiency of other engines, such as solar updraft towers, that also utilize the atmospheric temperature gradient but are limited by technical constraints to operate over a much lower altitude range. The increased efficiency allows the use of smaller area glazed collectors. Preliminary cost estimates suggest a lower $/W installation cost than equivalent power output tower engines. (author)

  20. Special theory on chemical engineering

    International Nuclear Information System (INIS)

    1987-06-01

    This book give a special description about chemical engineering. The contents of this book are special technique for isolation on introduction and separation by membrane, biochemistry engineering, process system engineering, energy engineering, environment engineering, a high molecular new material, election material and research on surface property of catalyst. It has appendixes on history of transition on Korean chemical engineering text contents and history of the activity of Korea chemical engineering institute.

  1. Engineering mathematics

    CERN Document Server

    Bird, John

    2014-01-01

    A practical introduction to the core mathematics required for engineering study and practiceNow in its seventh edition, Engineering Mathematics is an established textbook that has helped thousands of students to succeed in their exams.John Bird's approach is based on worked examples and interactive problems. This makes it ideal for students from a wide range of academic backgrounds as the student can work through the material at their own pace. Mathematical theories are explained in a straightforward manner, being supported by practical engineering examples and applications in order to ensure

  2. Engineering mathematics

    CERN Document Server

    Stroud, K A

    2013-01-01

    A groundbreaking and comprehensive reference that's been a bestseller since it first debuted in 1970, the new seventh edition of Engineering Mathematics has been thoroughly revised and expanded. Providing a broad mathematical survey, this innovative volume covers a full range of topics from the very basic to the advanced. Whether you're an engineer looking for a useful on-the-job reference or want to improve your mathematical skills, or you are a student who needs an in-depth self-study guide, Engineering Mathematics is sure to come in handy time and time again.

  3. Preliminary Evaluation of a Turbine/Rotary Combustion Compound Engine for a Subsonic Transport. [fuel consumption and engine tests of turbofan engines

    Science.gov (United States)

    Civinskas, K. C.; Kraft, G. A.

    1976-01-01

    The fuel consumption of a modern compound engine with that of an advanced high pressure ratio turbofan was compared. The compound engine was derived from a turbofan engine by replacing the combustor with a rotary combustion (RC) engine. A number of boost pressure ratios and compression ratios were examined. Cooling of the RC engine was accomplished by heat exchanging to the fan duct. Performance was estimated with an Otto-cycle for two levels of energy lost to cooling. The effects of added complexity on cost and maintainability were not examined and the comparison was solely in terms of cruise performance and weight. Assuming a 25 percent Otto-cycle cooling loss (representative of current experience), the best compound engine gave a 1.2 percent improvement in cruise. Engine weight increased by 23 percent. For a 10 percent Otto-cycle cooling loss (representing advanced insulation/high temperature materials technology), a compound engine with a boost PR of 10 and a compression ratio of 10 gave an 8.1 percent lower cruise than the reference turbofan.

  4. College of Engineering & Applied Science

    Science.gov (United States)

    Computational Mechanics Laboratory Environmental Engineering Laboratory Geotechnical Engineering Laboratory Engineering Concentration on Ergonomics M.S. Program in Computer Science Interdisciplinary Concentration on Energy Doctoral Programs in Engineering Non-Degree Candidate Departments Biomedical Engineering

  5. The electric power engineering handbook electric power transformer engineering

    CERN Document Server

    Harlow, James H

    2012-01-01

    Electric Power Transformer Engineering, Third Edition expounds the latest information and developments to engineers who are familiar with basic principles and applications, perhaps including a hands-on working knowledge of power transformers. Targeting all from the merely curious to seasoned professionals and acknowledged experts, its content is structured to enable readers to easily access essential material in order to appreciate the many facets of an electric power transformer.Topically structured in three parts, the book: * Illustrates for electrical engineers the relevant theories and pri

  6. Experience Engineering: An Engineering Course for Non-Majors

    Science.gov (United States)

    Hargrove-Leak, Sirena

    2012-01-01

    The engineering profession continues to struggle to attract new talent, in part because it is not well understood by the general public and often viewed in a negative light. Therefore, engineering professionals have called for new approaches promote better understanding and change negative perceptions. One suggested approach is for engineering…

  7. Thinking Like an Engineer: Using Engineering Habits of Mind and signature pedagogies to redesign Engineering Education

    OpenAIRE

    Lucas, Bill; Hanson, Janet

    2016-01-01

    In order to attract more young people into engineering\\ud and ensure that they are well equipped to meet\\ud future professional challenges we need to know how successful\\ud engineers think and act when faced with challenging\\ud problems. Using a mixed methods approach this study investigated\\ud the habits of mind that engineers use most frequently\\ud when engaged in the core activity of “making”\\ud things or “making things work better”. We identified the six\\ud most distinctive learning dispo...

  8. Are women engineers in Lebanon prepared for the challenges of an engineering profession?

    Science.gov (United States)

    Baytiyeh, Hoda

    2013-08-01

    This study investigates the status of women engineers in the Middle East, considering women engineers in Lebanon as a case study. The author investigated the following questions: What are the influences behind females' decisions to choose engineering as their major course of study? What are the motives behind this decision? What are the perceptions of females regarding the essential skills for a successful engineering career? An online survey consisting of Likert-scale items was completed by 327 female engineers who graduated from universities in Lebanon and now work in various locations around the world. A genuine interest in the field appeared to be the main influence in the participants' decisions to choose engineering profession. The potential for professional growth was the leading motivator for choosing engineering. Although participants reported that they possessed adequate theoretical knowledge and technical skills before graduation, in the actual practice of engineering, they noted weaknesses in creativity and innovation.

  9. Enhanced Engine Performance During Emergency Operation Using a Model-Based Engine Control Architecture

    Science.gov (United States)

    Csank, Jeffrey T.; Connolly, Joseph W.

    2016-01-01

    This paper discusses the design and application of model-based engine control (MBEC) for use during emergency operation of the aircraft. The MBEC methodology is applied to the Commercial Modular Aero-Propulsion System Simulation 40k (CMAPSS40k) and features an optimal tuner Kalman Filter (OTKF) to estimate unmeasured engine parameters, which can then be used for control. During an emergency scenario, normally-conservative engine operating limits may be relaxed to increase the performance of the engine and overall survivability of the aircraft; this comes at the cost of additional risk of an engine failure. The MBEC architecture offers the advantage of estimating key engine parameters that are not directly measureable. Estimating the unknown parameters allows for tighter control over these parameters, and on the level of risk the engine will operate at. This will allow the engine to achieve better performance than possible when operating to more conservative limits on a related, measurable parameter.

  10. Book of abstracts Chemical Engineering: IV All-Russian Conference on chemical engineering, All-Russian Youth Conference on chemical engineering, All-Russian school on chemical engineering for young scientists and specialists. Plenary reports. Engineering of inorganic substances and materials

    International Nuclear Information System (INIS)

    Zakhodyaeva, Yu.A.; Belova, V.V.

    2012-01-01

    In the given volume of abstracts of the IV All-Russian Conference on chemical engineering, All-Russian Youth Conference on chemical engineering, All-Russian school on chemical engineering for young scientists and specialists (Moscow, March 18-23, 2012) there are the abstracts of the reports concerning chemical engineering of inorganic substances and materials. The abstracts deal with state-of-the-art and future development of theoretical and experimental investigations as well as with experience in practical realization of development works in the field of chemical engineering and relative areas [ru

  11. Engineering education for youth: Diverse elementary school students' experiences with engineering design

    Science.gov (United States)

    Hegedus, Theresa

    Lingering concerns over the persistent achievement gap amidst the trend of an increasingly diverse society have been compounded by calls from the Oval Office, the National Science Board, and nationwide media to also address our current creativity crisis. Now, more than ever, we have a responsibility to produce a STEM-capable (science, technology, engineering, and mathematics) workforce to meet the demands of our rapidly changing local and global economic landscape. Barriers exist in our traditional educational system, which has historically limited underrepresented groups' affiliation and membership in the disciplines of science and engineering. The recent incorporation of engineering into the latest science education reform efforts presents an opportunity to expose students as early as elementary school to engineering practices and habits of mind, which have the potential to stimulate creative thinking skills through engineering design. This qualitative study was designed to examine the ways in which engineering education has the potential to promote creativity and academic competence in elementary science classrooms. As a part of my study, a diverse group of students from two fifth-grade classrooms took part in a 10-12 hour, engineering-based curriculum unit (Engineering is Elementary) during their regular science instructional time. Using a sociocultural lens, to include cultural production and identities in practice as part of my framework, I analyzed group and individual performances through classroom observations, student interviews, and teacher reflections to better understand the meaning students made of their experiences with engineering. Findings from the study included the ways in which creativity was culturally produced in the classroom to include: 1) idea generation; 2) design and innovation; 3) gumption/resourcefulness; and 4) social value. Opportunities for collaboration increased through each stage of the unit culminating with the design challenge

  12. Leveling the Playing Field: Teacher Perception of Integrated STEM, Engineering, and Engineering Practices

    Science.gov (United States)

    Fincher, Bridgette Ann

    The purpose of this study was to describe the perceptions and approaches of 14 third-through-fifth grade Arkansan elementary teachers towards integrative engineering and engineering practices during 80 hours of integrated STEM professional development training in the summer and fall of 2014. This training was known as Project Flight. The purpose of the professional development was to learn integrated STEM content related to aviation and to write grade level curriculum units using Wiggins and McTighe's Understanding by Design curriculum framework. The current study builds upon on the original research. Using a mixed method exploratory, embedded QUAL[quan] case study design and a non-experimental convenience sample derived from original 20 participants of Project Flight, this research sought to answer the following question: Does professional development influence elementary teachers' perceptions of the curriculum and instruction of integrated STEM engineering and engineering practices in a 3-to-5 grade level setting? A series of six qualitative and one quantitative sub-questions informed the research of the mixed method question. Hermeneutic content analysis was applied to archival and current qualitative data sets while descriptive statistics, independent t-tests, and repeated measures ANOVA tests were performed on the quantitative data. Broad themes in the teachers' perceptions and understanding of the nature of integrated engineering and engineering practices emerged through triangulation. After the professional development and the teaching of the integrated STEM units, all 14 teachers sustained higher perceptions of personal self-efficacy in their understanding of Next Generation Science Standards (NGSS). The teachers gained understanding of engineering and engineering practices, excluding engineering habits of mind, throughout the professional development training and unit teaching. The research resulted in four major findings specific to elementary engineering

  13. Software Engineering and Knowledge Engineering Theory and Practice Volume 2

    CERN Document Server

    2012-01-01

    The volume includes a set of selected papers extended and revised from the I2009 Pacific-Asia Conference on Knowledge Engineering and Software Engineering (KESE 2009) was held on December 19~ 20, 2009, Shenzhen, China.   Volume 2 is to provide a forum for researchers, educators, engineers, and government officials involved in the general areas of Knowledge Engineering and Communication Technology to disseminate their latest research results and exchange views on the future research directions of these fields. 135 high-quality papers are included in the volume. Each paper has been peer-reviewed by at least 2 program committee members and selected by the volume editor Prof.Yanwen Wu.   On behalf of the this volume, we would like to express our sincere appreciation to all of authors and referees for their efforts reviewing the papers. Hoping you can find lots of profound research ideas and results on the related fields of Knowledge Engineering and Communication Technology. 

  14. Engineers' Responsibilities for Global Electronic Waste: Exploring Engineering Student Writing Through a Care Ethics Lens.

    Science.gov (United States)

    Campbell, Ryan C; Wilson, Denise

    2017-04-01

    This paper provides an empirically informed perspective on the notion of responsibility using an ethical framework that has received little attention in the engineering-related literature to date: ethics of care. In this work, we ground conceptual explorations of engineering responsibility in empirical findings from engineering student's writing on the human health and environmental impacts of "backyard" electronic waste recycling/disposal. Our findings, from a purposefully diverse sample of engineering students in an introductory electrical engineering course, indicate that most of these engineers of tomorrow associated engineers with responsibility for the electronic waste (e-waste) problem in some way. However, a number of responses suggested attempts to deflect responsibility away from engineers towards, for example, the government or the companies for whom engineers work. Still other students associated both engineers and non-engineers with responsibility, demonstrating the distributed/collective nature of responsibility that will be required to achieve a solution to the global problem of excessive e-waste. Building upon one element of a framework for care ethics adopted from the wider literature, these empirical findings are used to facilitate a preliminary, conceptual exploration of care-ethical responsibility within the context of engineering and e-waste recycling/disposal. The objective of this exploration is to provide a first step toward understanding how care-ethical responsibility applies to engineering. We also hope to seed dialogue within the engineering community about its ethical responsibilities on the issue. We conclude the paper with a discussion of its implications for engineering education and engineering ethics that suggests changes for educational policy and the practice of engineering.

  15. Engineers: Designers--No Alibis.

    Science.gov (United States)

    Stevens, Susan A. R.; Wilkins, Linda C.

    Engineering is the science, art, and business of designing and getting things done; engineers are required to make things happen through interpersonal relationships. At Monash University (Australia), a new course, Management for Engineers, was set up in 1990 to encourage a more holistic approach to the process of engineering. The course included…

  16. Knowledge Service Engineering Handbook

    CERN Document Server

    Kantola, Jussi

    2012-01-01

    Covering the emerging field of knowledge service engineering, this groundbreaking handbook outlines how to acquire and utilize knowledge in the 21st century. Drawn on the expertise of the founding faculty member of the world's first university knowledge engineering service department, this book describes what knowledge services engineering means and how it is different from service engineering and service production. Presenting multiple cultural aspects including US, Finnish, and Korean, this handbook provides engineering, systemic, industry, and consumer use viewpoints to knowledge service sy

  17. LOW-ENGINE-FRICTION TECHNOLOGY FOR ADVANCED NATURAL-GAS RECIPROCATING ENGINES

    Energy Technology Data Exchange (ETDEWEB)

    Victor W. Wong; Tian Tian; Grant Smedley; Jeffrey Jocsak

    2004-09-30

    This program aims at improving the efficiency of advanced natural-gas reciprocating engines (ANGRE) by reducing piston/ring assembly friction without major adverse effects on engine performance, such as increased oil consumption and emissions. An iterative process of simulation, experimentation and analysis, are being followed towards achieving the goal of demonstrating a complete optimized low-friction engine system. To date, a detailed set of piston/ring dynamic and friction models have been developed and applied that illustrated the fundamental relationships between design parameters and friction losses. Various low-friction strategies and ring-design concepts have been explored, and engine experiments have been done on a full-scale Waukesha VGF F18 in-line 6 cylinder power generation engine rated at 370 kW at 1800 rpm. Current accomplishments include designing and testing ring-packs using a subtle top-compression-ring profile (skewed barrel design), lowering the tension of the oil-control ring, employing a negative twist to the scraper ring to control oil consumption. Initial test data indicate that piston ring-pack friction was reduced by 35% by lowering the oil-control ring tension alone, which corresponds to a 1.5% improvement in fuel efficiency. Although small in magnitude, this improvement represents a first step towards anticipated aggregate improvements from other strategies. Other ring-pack design strategies to lower friction have been identified, including reduced axial distance between the top two rings, tilted top-ring groove. Some of these configurations have been tested and some await further evaluation. Colorado State University performed the tests and Waukesha Engine Dresser, Inc. provided technical support. Key elements of the continuing work include optimizing the engine piston design, application of surface and material developments in conjunction with improved lubricant properties, system modeling and analysis, and continued technology

  18. Driving and engine cycles

    CERN Document Server

    Giakoumis, Evangelos G

    2017-01-01

    This book presents in detail the most important driving and engine cycles used for the certification and testing of new vehicles and engines around the world. It covers chassis and engine-dynamometer cycles for passenger cars, light-duty vans, heavy-duty engines, non-road engines and motorcycles, offering detailed historical information and critical review. The book also provides detailed examples from SI and diesel engines and vehicles operating during various cycles, with a focus on how the engine behaves during transients and how this is reflected in emitted pollutants, CO2 and after-treatment systems operation. It describes the measurement methods for the testing of new vehicles and essential information on the procedure for creating a driving cycle. Lastly, it presents detailed technical specifications on the most important chassis-dynamometer cycles around the world, together with a direct comparison of those cycles.

  19. Future trends in agricultural engineering.

    NARCIS (Netherlands)

    Jongebreur, A.A.; Speelman, L.

    1997-01-01

    Beside traditional mechanical engineering, other engineering branches such as electronics, control engineering and physics play their specific role within the agricultural engineering field. Agricultural engineering has affected and stimulated major changes in agriculture. In the last decades

  20. Applying systems engineering in the civil engineering industry : an analysis of systems engineering projects of a Dutch water board

    NARCIS (Netherlands)

    de Graaf, R. S. (Robin); Vromen, R. M.(Rick); Boes, J. (Hans)

    2017-01-01

    The past decade, practice and literature have shown an increasing interest in Systems Engineering (SE) in the civil engineering industry. The aim of this study is to analyse to what extent SE is applied in six civil engineering SE projects of a Dutch water board. The projects were analysed using a