bacteria desulfovibrio mutants: Topics by WorldWideScience.org

Uncoupler-resistant mutants of bacteria.

Washed cell suspensions of Desulfovibrio desulfuricans subsp. aestuarii were capable of reducing nanomolar levels of selenate to selenide as well as sulfate to sulfide....Full Text Available

1987-06-01

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Isolation of Assimilatory- and Dissimilatory-Type Sulfite Reductases from Desulfovibrio vulgaris

The chemiosmotic model of energy transduction offers a satisfying and widely confirmed understanding of the action of uncouplers on such processes as oxidative phosphorylation; the uncoupler, by facilitating...Full Text Available

1990-03-01

4

Energetics and kinetics of anaerobic aromatic and fatty acid degradation

Bisulfite reductase (desulfoviridin) and an assimilatory sulfite reductase have been purified from extracts of Desulfovibrio vulgaris. The bisulfite reductase has absorption maxima...Full Text Available

1973-08-01

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Construction and evaluation of a double mutant of Shigella flexneri as a candidate for oral vaccination against shigellosis.

The kinetics of benzoate degradation by the anaerobic syntrophic bacterium, Syntrophus buswellii, was studied in coculture with Desulfovibrio strain G11. The threshold value for benzoate degradation was dependent on the acetate concentration with benzoate threshold values ranging from 2.4 [mu]M at 20 mM acetate to 30.0 [mu]M at 65 mM acetate. Increasing acetate concentrations also inhibited the rate of benzoate degradation with a apparent K[sub i] for acetate inhibition of 7.0 mM. Lower threshold values were obtained when nitrate rather than sulfate was the terminal electron acceptor. These data are consistent with a thermodynamic explanation for the threshold, and suggest that there is a minimum Gibbs free energy value required for the degradation of benzoate. An acetoacetyl-CoA thiolase has been isolated from Syntrophomonas wolfei; it is apparently a key enzyme controlling the synthesis of poly-B-hydroxyalkanoate from acetyl-CoA in this organism. Kinetic ...

1992-11-16

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The molybdenum iron-sulphur protein from Desulfovibrio gigas as a form of aldehyde oxidase.

Based on studies on the genetic and molecular basis of Shigella flexneri invasive properties, we have constructed and evaluated a double mutant of S. flexneri serotype 5 for utilization as a live attenuated oral vaccine against shigellosis. The first mutation, icsA, blocks intracellular spread of bacteria as well as cell-to-cell infection. It affects the capacity of the invasive pathogen to form large abscesses in epithelia. The second mutation, iuc, eliminates production of the siderophore aerobactin thus impairing growth of the bacterium within tissues. This double mutant, SC5700 appeared safe when administered intragastrically to macaque monkeys as three doses (5 x 10(10) c.f.u. each) at weekly intervals. Protection against a challenge by the wild type isolate (M90T) was observed 4 weeks after the last vaccine inoculation. Duration of carriage was considerably reduced as compared to the control group in which all animals ...

1989-10-01

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In vitro and in vivo activities of T4 endonuclease V mutants altered in the C-terminal aromatic region

The molybdenum iron-sulphur protein originally isolated from Desulfovibrio gigas by Moura, Xavier, Bruschi, Le Gall, Hall & Cammack [(1976) Biochem. Biophys. Res. Commun. 72, 782-789] has been...Full Text Available

1987-05-01

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Microbial dynamics in upflow anaerobic sludge blanket (UASB) bioreactor granules in response to short-term changes in substrate feed

Genes encoding mutants of the thymine photodimer repair enzyme from bacteriophage T4 (T4 endonuclease V) having an amino acid substitution (T127M, W128A, W128S, Y129A, K130L, Y131A, Y132A) were constructed by use of a previously obtained synthetic gene and expressed in Escherichia coli under the control of the E. coli tryptophan promoter. An in vitro assay of partially fractionated mutant proteins for glycosylase activity was performed with chemically synthesized substrates containing a thymine photodimer. T127M and K130L showed almost the same activity as the wild-type protein. Although W128S, Y131A, and Y132A were slightly active, W128A and Y129A lost activity. The results indicated that the aromatic amino acids around position 130 may be important for the glycosylase activity. Mutant T127M was purified, and the Km value was found to be of the same order as that of the wild type (10(-8) M). In vivo activities for all ...

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Global Molecular Characterization of the Chromate Stress Response in Shewanella oneidensis MR-1: Identification of a Putative DNA-Binding Response Regulator and Azoreductase Involved in Cr(VI) Detoxification

The complexity and diversity of the microbial communities in biogranules from an upflow anaerobic sludge blanket (UASB) bioreactor were determined in response to short-term changes in substrate feeds. The reactor was fed simulated brewery wastewater (SBWW) (70% ethanol, 15% acetate, 15% propionate) for 1.5 months (phase 1), acetate / sulfate for 2 months (phase 2), acetate-alone for 3 months (phase 3), and then a return to SBWW for 2 months (phase 4). Performance of the reactor remained relatively stable throughout the experiment as shown by COD removal and gas production. 16S rDNA, methanogen-associated mcrA and sulfate reducer-associated dsrAB genes were PCR amplified, then cloned and sequenced. Sequence analysis of 16S clone libraries showed a relatively simple community composed mainly of the methanogenic Archaea (Methanobacterium and Methanosaeta), members of the Green Non-Sulfur (Chloroflexi) group of Bacteria, followed by fewer numbers of Syntrophobacter, ...

2010-08-01

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Role of the Yersinia pestis Ail Protein in Preventing a Protective Polymorphonuclear Leukocyte Response During Bubonic Plague.

Shewanella oneidensis MR-1 is a model environmental organism that possesses diverse respiratory capacities, including the ability to reduce soluble Cr(VI) to sparingly soluble, less toxic Cr(III). Effective bioremediation of Cr-contaminated sites requires knowledge of the molecular mechanisms and regulation of heavy metal resistance and biotransformation by dissimilatory metal-reducing bacteria. Towards this goal, our ERSP-funded work is focused on the identification and functional analysis of genes/proteins comprising the response pathways for chromate detoxification and/or reduction. Previous transcriptomic profiling and whole-cell proteomic analyses implicated the involvement of a functionally undefined DNA-binding response regulator (SO2426) and a putative azoreductase (SO3585) in the chromate stress response of MR-1. Here we describe a detailed functional analysis of SO2426 and SO3585 in order to begin to understand the role of these proteins in the cellular ...

2006-04-05

11

The type III secretion system is involved in Escherichia coli K1 interactions with Acanthamoeba

The ability of Yersinia pestis to forestall the mammalian innate immune response is a fundamental aspect of plague pathogenesis. In this study, we examined the effect of Ail, a 17-kDa outer membrane protein that protects Y. pestis against complement-mediated lysis, on bubonic plague pathogenesis in mice and rats. The Y. pestis ail mutant was attenuated for virulence in both rodent models. The attenuation was greater in rats than in mice, which correlates with the ability of normal rat serum, but not mouse serum, to kill ail-negative Y. pestis in vitro. Intradermal infection with the ail mutant resulted in an atypical, subacute form of bubonic plague associated with extensive recruitment of polymorphonuclear leukocytes (PMN or neutrophils) to the site of infection in the draining lymph node and the formation of large purulent abscesses that contained the bacteria. Systemic spread and mortality were greatly attenuated, ...

2011-10-01

12

British Library Electronic Table of Contents (United Kingdom)

The type III secretion system among Gram-negative bacteria is known to deliver effectors into host cell to interfere with host cellular processes. The type III secretion system in Yersina, Pseudomonas and Enterohemorrhagic Escherichia coli have been well documented to be involved in the bacterial pathogenicity. The existence of type III secretion system has been demonstrated in neuropathogenic E. coli K1 strains. Here, it is observed that the deletion mutant of type III secretion system in E. coli strain EC10 exhibited defects in the invasion and intracellular survival in Acanthamoeba castellanii (a keratitis isolate) compared to its parent strain. Next, it was determined whether type III secretion system plays a role in E. coli K1 survival inside Acanthamoeba during the encystment process...

2011-01-01

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Screening of Multifunctional Bacteria with Biocontrol and Biofertilizing Effects

Effect of Spices on the Growth of Pathogenic Bacteria

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2011-08-01

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The Arabidopsis ref2 Mutant Is Defective in the Gene Encoding CYP83A1 and Shows Both Phenylpropanoid and Glucosinolate Phenotypes

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1997-08-01

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Nitrogen fixation in nitrate reductase-deficient mutants of cultured rhizobia.

The Arabidopsis ref2 mutant was identified in a screen for plants having altered fluorescence under UV light. Characterization of the ref2 mutants showed that they...Full Text Available

2003-01-01

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Hormonal Characterization of a Nonrooting Naphthalene-Acetic Acid Tolerant Tobacco Mutant by an Immunoenzymic Method

Forty-eight mutants unable to reduce nitrate were isolated from "cowpea" Rhizobium sp. strain 32Hl and examined for nitrogenase activity in culture. All but two of the mutants had nitrogenase activity...Full Text Available

1977-02-01

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Regulation of Glutamate Dehydrogenases in nit-2 and am Mutants of Neurospora crassa

The comparative analysis of plant hormones was undertaken on a 1-naphthaleneacetic acid tolerant mutant and normal tobacco (Nicotiana tabacum cv Xanthi) plantlets. The mutant plantlet...Full Text Available

1989-01-01

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Novel strategy for isolating suppressors of meiosis-deficient mutants and its application for isolating the bcy1 suppressor

The regulation of the glutamate dehydrogenases was investigated in wild-type Neurospora crassa and two classes of mutants altered in the assimilation of inorganic nitrogen, as either...Full Text Available

1979-03-01

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Genetic Control of Capsid Length in Bacteriophage T4 I. Isolation and Preliminary Description of Four New Mutants

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1997-03-01

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Distribution of Calretinin-immunoreactive Unipolar Brush Cells in Ataxic Mutant Pogo Mice Cerebellum

Four new mutants are described whose phenotypic expression affects the length of the head of bacteriophage T4D. All mutants produce some phenotypically normal phage particles. Mutant pt21-34...Full Text Available

1973-08-01

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Sortases and the Art of Anchoring Proteins to the Envelopes of Gram-Positive Bacteria

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2005-08-01

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Comparative analysis of nitrifying bacteria associated with freshwater and marine aquaria.

The cell wall envelopes of gram-positive bacteria represent a surface organelle that not only functions as a cytoskeletal element but also promotes interactions between bacteria and their environment....Full Text Available

2006-03-01

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Effect of different nitroheterocyclic compounds on aerobic, microaerophilic, and anaerobic bacteria.

Three nucleic acid probes, two for autotrophic ammonia-oxidizing bacteria of the beta subdivision of the class Proteobacteria and one for alpha subdivision nitrite-oxidizing bacteria, were developed...Full Text Available

1996-08-01

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Soybean Mutants Lacking Constitutive Nitrate Reductase Activity 1

The antibacterial activities of different nitroheterocyclic compounds were assessed by an agar dilution method against aerobic, microaerophilic, and anaerobic bacteria. Nitronaphthofurans inhibited...Full Text Available

1986-11-01

25

Retrograde neuronal tracing with a deletion-mutant rabies virus

The objectives of this study were to select and initially characterize mutants of soybean (Glycine max L. Merr. cv Williams) with decreased ability to reduce nitrate. Selection involved...Full Text Available

1983-06-01

26

Reduced Accumulation of ABA during Water Stress in a Molybdenum Cofactor Mutant of Barley ¹

We have constructed a deletion-mutant rabies virus encoding EGFP and find it to be an excellent tool for studying detailed morphology and physiology of neurons projecting to injection sites...Full Text Available

2007-01-01

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Prevention of clinical coliform mastitis in dairy cows by a mutant Escherichia coli vaccine.

A barley (Hordeum vulgare L.) mutant (Az34) has been identified with low basal levels of abscisic acid (ABA) and with reduced capacity for producing ABA in response to water stress....Full Text Available

1989-06-01

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Photophysics and optical switching in green fluorescent protein mutants

A prospective cohort study was undertaken in two commercial California dairies. The treatment group, 246 cows, received three doses of a whole cell bacterin of J5 Escherichia coli (mutant of E. coli...Full Text Available

1989-07-01

29

O2-dependent methionine auxotrophy in Cu,Zn superoxide dismutase-deficient mutants of Saccharomyces cerevisiae.

We demonstrate by using low-temperature high-resolution spectroscopy that red-shifted mutants of green fluorescent protein are photo-interconverted among three conformations and are, therefore, not...Full Text Available

2000-03-28

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Molybdoenzyme biosynthesis in Escherichia coli: in vitro activation of purified nitrate reductase from a chlB mutant.

Mutant strains of the yeast Saccharomyces cerevisiae which lack functional Cu,Zn superoxide dismutase (SOD-1) do not grow aerobically unless supplemented with methionine. The molecular basis of this...Full Text Available

1990-04-01

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Involvement of a low-molecular-weight substance in in vitro activation of the molybdoenzyme respiratory nitrate reductase from a chlB mutant of Escherichia coli.

All molybdoenzyme activities are absent in chlB mutants because of their inability to synthesize molybdopterin guanine dinucleotide, which together with molybdate constitutes the molybdenum cofactor...Full Text Available

1992-12-01

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DNA replication in Escherichia coli mutants that lack protein HU.

The soluble subcellular fraction of a chlB mutant contains an inactive precursor form of the molybdoenzyme nitrate reductase, which can be activated by the addition to the soluble fraction of protein...Full Text Available

1987-10-01

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Biochemical Characterization of Soybean Mutants Lacking Constitutive NADH:Nitrate Reductase ¹

DNA replication in Escherichia coli cells lacking protein HU was studied. HU has been suggested to be involved in the initiation of replication from in vitro studies. The isolated HU mutants, however,...Full Text Available

1989-10-01

34

Analysis of the astray/robo2 zebrafish mutant reveals that degenerating tracts do not provide strong guidance cues for regenerating optic axons

Two nitrate reductase (NR) mutants were selected for low nitrate reductase (LNR) activity by in vivo NR microassays of M₂ seedlings derived from nitrosomethylurea-mutagenized...Full Text Available

1986-06-01

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Aldehyde Oxidase and Xanthine Dehydrogenase in a flacca Tomato Mutant with Deficient Abscisic Acid and Wilty Phenotype1

During formation of the optic projection in astray/robo2 mutant zebrafish, optic axons exhibit rostro-caudal pathfinding errors, ectopic midline crossing and...Full Text Available

2010-10-13

36

Morphological descriptions of some induced systematic mutants of grapes (Vitis vinifera L.)

The flacca tomato (Lycopersicon esculentum) mutant displays a wilty phenotype as a result of abscisic acid (ABA) deficiency. The Mo cofactor (MoCo)-containing aldehyde...Full Text Available

1999-06-01

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Isolation of deoxynivalenol-transforming bacteria from the chicken intestines using the approach of PCR-DGGE guided microbial selection.

(1972). Germany Sharma, RL Himachal Pradesh Univ., Palampur (India).

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Primary study on lesion mimic mutants of rice (oryza sativa L.)

PMID:20576129

2010-06-24

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Syntrophic microorganisms in anaerobic environments. Zettai kenki kankyoka ni okeru biseibutsu no kyosei

Nineteen lesion mimic mutants (xsl1-19) of japonica rice Xiushui11 were obtained by ?-rays irradiation treatment. All mutants belonged to whole life lesion mimic. Lesion mimic of mutants didn't largen after tillering stage, leaves didn't wither, and no effect on the plants exsert spikes and seed. When the highest temperature in day exceeded 32 degree C in seedling stage, lesion mimic of all mutant expect xsl19 disappeared. Under 32 degree C, lesion mimic would appear gradually, and symptoms weren't inhibited by high temperature after 5 leaf stage. The plant heights of all lesion mimic mutants were 47.56-63.54 cm in the tillering stage, and that of CK was 83.75 cm; but the dwarf phenomenon of mutants only appeared before tillering stage, and didn't affect plant heights finally; the heading dates of mutants were the same to the CK, the ear ...

2007-08-01

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Evolution of improved varieties of sesame through induced mutations

The most classic information on the syntrophic microorganisms in an anaerobic bacteria symbiotic system may be methanobacillus omelianskii. These bacteria were isolated as ones degrading alcohols such as ethanol into methane and were stably preserved for more than 20 years. But, it was clarified by later researches that this was a kind of symbiotic cocultivation system of the bacteria (S strain) which oxidizes ethanol into acetic acid, hydrogen, and carbon dioxide, and a kind of bacteria of the methanobacterium genus which produces or synthesizes methane from hydrogen and carbon dioxide. Such a symbiotic system of two kinds of anaerobic bacteria is the one of a kind of bacteria which produces hydrogen by oxidizing substances and of another kind of bacteria which consume hydrogen. Various kinds of symbiotic systems including those of ...

1992-07-10

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Study of Nitrate Stress in Desulfovibrio vulgaris Hildenborough Using iTRAQ Proteomics

Sesame varieties/genotypes showed a good response to radiation with gamma rays and treatments with EMS. In M_1 both gamma rays and EMS influenced germination, seedling height, survival of plants and pollen fertility/sterility, producing deleterious effects on these characters. Compared to black seeded genotypes, white seeded ones are more susceptible to radiation. Both gamma rays and EMS produced various types of morphological variations in M_2 generation. These were dwarf plant mutants, mottled and fleshy leaved mutants (sterile), fasciated stem, flower colour, altered phyllotaxy, early, uniculm, capsule size variations, multiple capsule/leaf axil, seed coat colour variations, indehiscent and semi-indehiscent type mutants. Moreover, studies on quantitative characters including seed yield revealed the induction of mutants in both positive and negative directions for such traits which made a good scope ...

2001-01-01

42

Role of periodontal pathogenic bacteria in RANKL-mediated bone destruction in periodontal disease

The response of Desulfovibrio vulgaris Hildenborough (DvH),a sulphate-reducing bacterium, to nitrate stress was examined usingquantitative proteomic analysis. DvH was stressed with 105 m M sodiumnitrate(NaNO3), a level that caused a 50 percent inhibition in growth.The protein profile of stressed cells was compared with that of cellsgrown in the absence of nitrate using the iTRAQ peptide labellingstrategy and tandem liquid chromatography separation coupled with massspectrometry (quadrupoletime-of-flight) detection. A total of 737 uniqueproteins were identified by two or more peptides, representing 22 percentof the total DvH proteome and spanning every functional category. Theresults indicate that this was a mild stress, as proteins involved incentral metabolism and the sulphate reduction pathway were unperturbed.Proteins involved in the nitrate reduction pathway increased. Increasesseen in transport systems for proline, glycine^ betaineandglutamateindicate that the ...

2006-10-12

43

Numerical Taxonomy of Some Bacteria Isolated from Antarctic and Tropical Seawaters¹

Accumulated lines of evidence suggest that hyperimmune responses to periodontal bacteria result in the destruction of periodontal connective tissue and alveolar bone. The etiological roles of periodontal...Full Text Available

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Nitrogen Cycling and Community Structure of Proteobacterial ?-Subgroup Ammonia-Oxidizing Bacteria within Polluted Marine Fish Farm Sediments

Pfister, Robert M. (Lamont Geological Observatory, Palisades, N.Y.), and Paul R. Burkholder. Numerical taxonomy of some bacteria isolated from Antarctic and tropical seawaters. J....Full Text Available

1965-10-01

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Modification of Spatial Distribution of 2,4-Dichlorophenoxyacetic Acid Degrader Microhabitats during Growth in Soil Columns

A multidisciplinary approach was used to study the effects of pollution from a marine fish farm on nitrification rates and on the community structure of ammonia-oxidizing bacteria in the underlying...Full Text Available

1999-01-01

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Lizards in the ecology of salmonellosis in Panama.

Bacterial processes in soil, including biodegradation, require contact between bacteria and substrates. Knowledge of the three-dimensional spatial distribution of bacteria at the microscale is necessary...Full Text Available

2004-05-01

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Isolation and characterization of quinoline-degrading bacteria from subsurface sediments.

Enteropathogenic bacteria was isolated from 131 of 447 (29.4%) neotropical Panamanian lizards belonging to 34 species of seven families. Overall, 147 strains of bacteria were isolated comprising 26...Full Text Available

1981-05-01

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Insights into the Genome of Large Sulfur Bacteria Revealed by Analysis of Single Filaments

Two gram-negative, motile bacteria isolated from deep subsurface sediments mineralized the nitrogen-containing polyaromatic hydrocarbon quinoline under aerobic conditions and transformed quinoline to...Full Text Available

1989-04-01

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Influence of Species Specificity and Other Factors on Bacteria Associated with the Coral Stylophora pistillata in Taiwan ?

Marine sediments are frequently covered by mats of the filamentous Beggiatoa and other large nitrate-storing bacteria that oxidize hydrogen sulfide using either oxygen or nitrate, which...Full Text Available

2007-09-01

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Identification of immune genes and proteins involved in the response of bovine mammary tissue to Staphylococcus aureus infection

Species of bacteria associated with Stylophora pistillata were determined by analyses of 16S ribosomal genes. Coral samples were taken from two distinct sites at Kenting, in the far...Full Text Available

2009-12-01

51

Growth, cell division and sporulation in mycobacteria

BackgroundMastitis in dairy cattle results from infection of mammary tissue by a range of micro-organisms but principally coliform bacteria and Gram positive bacteria such as Staphylococcus...Full Text Available

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Functional Exoenzymes as Indicators of Metabolically Active Bacteria in 124,000-Year-Old Sapropel Layers of the Eastern Mediterranean Sea

Bacteria have the ability to adapt to different growth conditions and to survive in various environments. They have also the capacity to enter into dormant states and some bacteria form spores when...Full Text Available

2010-08-01

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Evaluation of broth disk elution methods for susceptibility testing of anaerobic bacteria with the newer beta-lactam antibiotics.

Hydrolytic exoenzymes as indicators of metabolically active bacteria were investigated in four consecutive sapropel layers collected from bathyal sediments of the eastern Mediterranean Sea. For comparison,...Full Text Available

2000-06-01

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Enrichment of Thermophilic Propionate-Oxidizing Bacteria in Syntrophy with Methanobacterium thermoautotrophicum or Methanobacterium thermoformicicum

Broth disk elution procedures represent one of the most practical means for clinical laboratories to perform routine antibiotic susceptibility tests on anaerobic bacteria. The accuracy of five disk...Full Text Available

1986-03-01

55

Detection of Unculturable Bacteria in Periodontal Health and Disease by PCR

Thermophilic propionate-oxidizing, proton-reducing bacteria were enriched from the granular methanogenic sludge of a bench-scale upflow anaerobic sludge bed reactor operated at 55°C with a mixture...Full Text Available

1992-01-01

56

Comparison of oral and vaginal metronidazole for treatment of bacterial vaginosis in pregnancy: impact on fastidious bacteria

Recently developed molecular methods have made it possible to characterize mixed microflora in their entirety, including the substantial numbers of bacteria which do not grow on artificial culture media....Full Text Available

1999-05-01

57

Chemical structure and inhalation toxicity of lipopolysaccharides from bacteria on cotton.

BackgroundBacterial vaginosis (BV) is a common condition that is associated with preterm birth and acquisition of complex communities of vaginal bacteria that include several fastidious...Full Text Available

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Antibiotic resistance of gram-negative enteric bacteria from pigs in three herds with different histories of antibiotic exposure.

Lipopolysaccharides from different bacteria isolated from cotton were purified and chemically analyzed. Their pulmonary toxicity to animals was tested in inhalation tests. Lipopolysaccharides from Agrobacterium...Full Text Available

1980-09-01

59

AGEs Secreted by Bacteria Are Involved in the Inflammatory Response

The antibiotic resistance patterns of gram-negative fecal bacteria from pigs in three herds with different histories of antibiotic exposure were examined. In general, smaller proportions of antibiotic-resistant...Full Text Available

1989-09-01

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Soil microbial toxicity of eight polycyclic aromatic compounds: effects on nitrification, the genetic diversity of bacteria, and the total number of protozoans.

Advanced Glycated End Products (AGEs) are formed by non-enzymatic protein glycation and are implicated in several physiological aspects including cell aging and diseases. Recent data indicate that bacteria...Full Text Available

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DEFF Research Database (Denmark)

Udgivelsesdato: 2002-Aug

2002-01-01

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Screening of Bacteria Producing Lipase from Insect Gut: Isolation and Characterization of a Strain, Burkholderia sp. HY-10 Producing Lipase

In Situ Detection, Isolation, and Physiological Properties of a Thin Filamentous Microorganism Abundant in Methanogenic Granular Sludges: a Novel Isolate Affiliated with a Clone Cluster, the Green Non-Sulfur Bacteria, Subdivision I

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2007-04-01

63

The vacuolar processing enzyme (VPE) mutation suppresses an HR-like cell death induced by the double knockout mutant of vacuolar Ca2+-ATPases in Arabidopsis

We previously showed that very thin filamentous bacteria affiliated with the division green non-sulfur bacteria were abundant in the outermost layer of thermophilic methanogenic sludge granules fed...Full Text Available

2001-12-01

64

Paraquat toxicity is increased in Escherichia coli defective in the synthesis of polyamines

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2011-06-01

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Hormonal Control of Cell Proliferation Requires PASTICCINO Genes

The authors have shown that toxicity of paraquat for Escherichia coli is increased over 1-fold in strains defective in the biosynthesis of spermidine compared to isogenic strains containing spermidine. The increased sensitivity of these spermidine-deficient mutants to paraquat is eliminated by growth in medium containing spermidine or by endogenous supplementation of spermidine by the use of a speE"+D"+ plasmid. No paraquat toxicity is seen in the absence of oxygen, even in amine-deficient strains, indicating that superoxide is the agent responsible for the increased toxicity. However, the specific mechanisms responsible for the increased paraquat toxicity in the spermidine-deficient mutants remain to be determined. The marked sensitivity to paraquat of E. coli deficient in spermidine is of particular interest, since such mutants have no other phenotypic properties that can be easily assayed. This increased sensitivity has ...

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Effect of salt stress and phosphorus deficiency in mutants of rhizobium obtained by gamma irradiation

PASTICCINO (PAS) genes are required for coordinated cell division and differentiation during plant development. In loss-of-function pas mutants,...Full Text Available

2003-07-01

67

Defective gut function in drop-dead mutant Drosophila

Two strains of Rhizobium: Rhizobium Tropici and Mesorhizobium Ciceri nodulating respectively common bean and chickpea were treated by gamma irradiation (60Co) source. Radiosensibility analysis showed that 800 Gy was the biggest dose supported by these two strains. We isolated gamma irradiated resistant strain in order to select mutant of them which can supported salt stress and phosphorus deficiency. Salinity analysis showed that Mesorhizobium Ciceri 835 strain, can tolerate up to 18g/l (273 mM NaCl) of salt, whereas, their irradiation mutants tolerate salinity up to 33g/l (564mM. NaCl) Rhizobium Tropici CIAT899 can survive at 20g/l (342 mM) either for control strain or mutants. Analysis of phosphorus deficiency showed that either Rhizobium Tropici CIAT899, or Mesorhizobium Ciceri 835 can survive in medium without phosphore. Our results permit us to screen mutants tolerant to these stresses wide spread ...

2008-08-12

68

Defective Glycinergic Synaptic Transmission in Zebrafish Motility Mutants

Mutation of the gene drop-dead (drd) causes adult Drosophila to die within 2 weeks of eclosion and is associated with reduced rates of defecation...Full Text Available

2009-09-01

69

Two proteins encoded at the chlA locus constitute the converting factor of Escherichia coli chlA1.

Glycine is a major inhibitory neurotransmitter in the spinal cord and brainstem. Recently, in vivo analysis of glycinergic synaptic transmission has been pursued in zebrafish using...Full Text Available

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Relationship of large and small invertases in Saccharomyces: mutant selectively deficient in small invertase.

Molybdopterin (MPT) is not produced by the Escherichia coli mutants chlA1, chlM, or chlN or by the Neurospora crassa mutant nit-1. Extracts of E. coli chlA1 contain an activity, the converting factor,...Full Text Available

1989-06-01

71

RecA protein acts at the initiation of stable DNA replication in rnh mutants of Escherichia coli K-12.

A mutant strain of Saccharomyces cerevisiae (D10-ER1) has been isolated after a two-step mutagenesis of strain 4059-358D (SUC 1) using ethyl methane sulfonate. Cells of this new strain produced a level...Full Text Available

1978-09-01

72

Isolation and Initial Characterization of Constitutive Nitrate Reductase-Deficient Mutants NR328 and NR345 of Soybean (Glycine max) ¹

Escherichia coli rnh mutants lacking RNase H activity are capable of recA+-dependent DNA replication in the absence of concomitant protein synthesis (stable DNA replication). In rnh dnaA::Tn10 and rnh...Full Text Available

1985-08-01

73

Impaired neonatal survival of pro-opiomelanocortin null mutants.

Two nitrate reductase deficient mutants of soybean (Glycine max [L.] Merr. cv Bragg) were isolated from approximately 10,000 M₂ seedlings, using a direct enzymic assay in...Full Text Available

1986-06-01

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Comparison between NO_x Evolution Mechanisms of Wild-Type and nr₁ Mutant Soybean Leaves ¹

Intercrosses of heterozygous pro-opiomelanocortin (POMC) mice result in homozygous null progeny at lower frequencies than expected. Genotyping offspring at pre-, peri-, and postnatal stages revealed that over half of homozygous null mutants die in the early postnatal stages. To investigate the reasons for this early postnatal lethality, we analyzed in detail different parameters in the initial hours after birth. POMC null mutants born to heterozygous dams presented at birth with corticosterone levels no different from wildtype littermates, were euglycemic, and had normal liver glycogen stores. However, already 30 min after birth corticosterone levels dropped by 80% and were undetectable thereafter, while corticosterone levels in wildtype animals increased during postnatal hours. Circulating adrenaline was almost below detection 1h after birth. Blood glucose levels fell sharply in all genotypes within 30 min after birth; however, wildtype and ...

2010-12-22

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Assembly of 60S ribosomal subunits is perturbed in temperature-sensitive yeast mutants defective in ribosomal protein L16.

The nr₁ soybean (Glycine max [L.] Merr.) mutant does not contain the two constitutive nitrate reductases, one of which is responsible for enzymic conversion of nitrite to...Full Text Available

1990-05-01

76

The reaction of hydroxylamine with bacteriorhodopsin studied with mutants that have altered photocycles: Selective reactivity of different photointermediates

Temperature-sensitive mutants defective in 60S ribosomal subunit protein L16 of Saccharomyces cerevisiae were isolated through hydroxylamine mutagenesis of the RPL16B gene and plasmid shuffling. Two...Full Text Available

1991-11-01

77

Evaluation of some lupin mutants under different irrigation intervals and nitrogen fertilizer levels

The reaction of the retinylidene Schiff base in bacteriorhodopsin (bR) to the water-soluble reagent hydroxylamine is enhanced by greater than 2 orders of magnitude under illumination. We have used this reaction as a probe for changes in Schiff base reactivity during the photocycle of wild-type bR and mutants defective in proton transport. We report here that under illumination at pH 6, the D85N mutant has a 20-fold lower rate and the D212N mutant has a greater than 4-fold higher rate for the light-dependent reaction with hydroxylamine compared with wild-type bR. In contrast, the reactivities of wild-type bR and the D96N and T46V mutants are similar. It has been previously shown that the D96N and T46V replacements have no significant effect on the kinetics of M formation but have dramatic effects on rate of the decay of M. We therefore conclude that the hydroxylamine reaction occurs before formation of ...

1991-03-15

78

Evaluation of induced peanut mutant (RT-1010) for Pod yield, oil yield and resistant to aspergillus spp. invation and aflatoxin contamination

This investigation was carried out during the two seasons of 1998/1999 and 1999/2000 at the experimental farm belonging to the plant research department, nuclear research center, atomic energy authority in Inshas to evaluate four lupin mutant lines (L_1, L_2, L_3 and L_4) along with their original mother varieties giza 1 and giza 2 under different levels and nitrogen fertilizer levels. The results indicated that seed yield/ plant and its effective components number and weight of pods/plant were significantly higher in all the mutant lines as compared to their parents either in the first or second seasons. Concerning the effect of irrigation intervals on yield and its components for developed mutants and their mother varieties as well as the results gave an evidence that the wider interval showed the lesser values for yield and most of yield components. Obtained data also revealed that yield attributes of lupin ...

2002-04-01

79

Thermokinetic investigation of effects of carbon source on petroleum bacterial growth

An induced mutant, RT-10 (M6 generation) was re-irradiated with 300 Gy of gamma rays. In M2 generation a mutant plant was identified, which characterized with large pods, prominent longitudinal ribbon reticulation and slight constriction. The selected mutant, RT-1010 has the highest pod yield (.3.59 t/fed.vs.2.91 and 2.61 t/fed respectively) and harvest index ( 0.52 vs. 0.42 and 0.45 resp.), the best in fancy pods percentage (57.67 % vs. 38.33 % and 44.17 % resp.), TSMK grade (98.96 % vs. 83.03 % and 84.05 % resp.), the largest pod mass (253.37 g vs . 211.32 g and 222.19 g resp.) and the highest expected oil yield (1370 Kg/fed vs. 895.44 Kg and 868.17 Kg/fed. resp.). With regard to fatty acid compositions, both the selected mutant, RT-1010 and the parental mutant RT-10 have almost a similar high oleic fatty acid (C18:1) percentage (56.35 % and 55.103 % respectively), low linoleic ...

2010-01-01

80

Sirtuins, Bioageing, and Cancer

The growth power-time curves of a strain of petroleum bacteria, B-2, in various kinds of cultures containing different kinds of carbon sources, glucose, n-tetradecane, n-hexadecane and n-octadecane, and different kinds of microemulsions have been determined by using a 2277 Thermal Activity Monitor. The curves showed a single peak for cultures containing a single carbon source, glucose, and two peaks for cultures containing two kinds of carbon sources, glucose and one of the n-alkanes. The first peak indicated that bacteria grew by consuming glucose and the second peak indicated that bacteria grew by consuming n-alkane. The curves were complex when the bacterium grows in a microemulsion culture. According to a kinetic equation of bacterial growth under limited conditions, the rate constants of bacterial growth were obtained. The results showed that the microemulsion culture was more appropriate to ...

2002-02-07

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81

Probiotic Bacteria as Biological Control Agents in Aquaculture

The Sirtuins are a family of orthologues of yeast Sir2 found in a wide range of organisms from bacteria to man. They display a high degree of conservation between species, in both sequence and function,...Full Text Available

82

Growth regulation of Legionella Pneumophila in biofilms and amoebae; Wachstumsregulation von Legionella Pneumophila in Biofilmen und Amoeben

There is an urgent need in aquaculture to develop microbial control strategies, since disease outbreaks are recognized as important constraints to aquaculture production and trade and since the development...Full Text Available

2000-12-01

83

Factors Influencing the Effectiveness of Swimming Pool Bactericides

This final report for the Swiss Federal Office of Energy (SFOE) presents the results of studies made on the regulation of the growth of Legionella Pneumophila bacteria in biofilms and amoebae. In a first project, the formation of biofilms by Legionella Pneumophila bacteria was analysed in static and dynamic systems using a complex growth medium. Under static and dynamic clinical and environmental conditions, the adherence of the biofilms on polystyrene tissue was studied. This was also examined under dynamic flow conditions. In a second part of the project, the regulation of growth of Legionella Pneumophila in amoebae was examined in that changes were made to the genome of the bacteria. The importance of the work for the de-activation of Legionella Pneumophila bacteria in biofilms is noted in the conclusions of the report.

2006-07-01

84

FLUOROMETRIC MEASUREMENT OF OXIDATIVE BURST IN LOBSTER HEMOCYTES AND INHIBITING EFFECT OF PATHOGENIC BACTERIA AND ...

Techniques for culturing, harvesting, and testing bacteria to evaluate bactericidal chemicals for swimming pools are described. Concentrations of 25, 50, and 100 mg of the chlorine stabilizer cyanuric...Full Text Available

1967-05-01

85

Eukaryotic Diversity in an Anaerobic Aquifer Polluted with Landfill Leachate?

... Hunter. 2003. The resistance to ammonia stress of Penaeus monodon Fabricius juveniles fed diets supplemented with astaxanthin. J. Exp. ... ...

86

Detection and Identification of Bacteria by Gas Chromatography¹

Eukaryotes may influence pollutant degradation processes in groundwater ecosystems by activities such as predation on bacteria and recycling of nutrients. Culture-independent community profiling and...Full Text Available

2008-07-01

87

Degradation of malathion by salt-marsh microorganisms.

Ether extracts of cultures of 29 strains representing 6 species of Bacillus, and of individual strains of Escherichia coli, Aerobacter aerogenes, and Pseudomonas...Full Text Available

1966-07-01

88

Biosorption of heavy metal ions on Rhodobacter sphaeroides and Alcaligenes eutrophus H16

Numerous bacteria from a salt-marsh environment are capable of degrading malathion, an organophosphate insecticide, when supplied with additional nutrients as energy and carbon sources. Seven isolates...Full Text Available

1977-02-01

89

Involvement of a putative response regulator Brrg-1 in the regulation of sporulation, sensitivity to fungicides, and osmotic stress in Botrytis cinerea

A fundamental study of the application of bacteria to the recovery of toxic heavy metals from aqueous environments was carried out. The biosorption characteristics of cadmium and lead ions were determined with purple nonsulfur bacteria, Rhodobacter sphaeroides and hydrogen bacteria, Alcaligenes eutrophus H16 that were inactivated by steam sterilization. A simplified version of the metal binding model proposed by Plette et al. was used for the description of meal binding data. The results showed that the biosorption of bivalent metal ions to whole cell bodies of the bacteria was due to monodentate binding to two different types of acidic sites: carboxilic and phosphatic-type sites. The number of metal binding sites of A. eutrophus was 2.4-fold larger than that of R. sphaeroides.

1998-01-15

90

British Library Electronic Table of Contents (United Kingdom)

The response regulator protein is a core element of two-component signaling pathway. In this study, we investigated functions of BRRG-1 of Botrytis cinerea, a gene that encodes a putative response regulator protein, which is homologous to Rrg-1 in Neurospora crassa. The BRRG-1 gene deletion mutant ?Brrg1-62 was unable to produce conidia. The mutant showed increased sensitivity to osmotic stress mediated by NaCl and KCl, and to oxidative stress generated by H2O2. Additionally, the mutant was more sensitive to the fungicides iprodione, fludioxonil, and triadimefon than the parental strain. Western-blot analysis showed that the Bos-2 protein, the putative downstream component of Brrg-1, was not phosphorylated in the ?Brrg1-62. Real-time polymerase chain reaction assays showed that expression ...

2011-01-01

91

Vibrational spectroscopy of bacteriorhodopsin mutants: light-driven proton transport involves protonation changes of aspartic acid residues 85, 96, and 212

The first long-lived mutants: discovery of the insulin/IGF-1 pathway for ageing

Fourier transform infrared (FTIR) difference spectra have been obtained for the bR----K, bR----L, and bR----M photoreactions in bacteriorhodopsin mutants in which Asp residues 85, 96, 115, and 212 have been replaced by Asn and by Glu. Difference peaks that had previously been attributed to Asp COOH groups on the basis of isotopic labeling were absent or shifted in these mutants. In general, each COOH peak was affected strongly by mutation at only one of the four residues. Thus, it was possible to assign each peak tentatively to a particular Asp. From these assignments, a model for the proton-pumping mechanism of bR is derived, which features proton transfers among Asp-85, -96, and -212, the chromophore Schiff base, and other ionizable groups within the protein. The model can explain the observed COOH peaks in the FTIR difference spectra of bR photointermediates and could also account for other recent results on site-directed ...

1988-11-15

92

The adenovirus-2 EIIa early gene promoter: sequences required for efficient in vitro and in vivo transcription.

Inhibiting insulin/IGF-1 signalling extends lifespan and delays age-related disease in species throughout the animal kingdom. This life-extension pathway, the first to be defined, was discovered through...Full Text Available

2011-01-12

93

Purification and properties of penicillinases from two strains of Bacillus licheniformis: a chemical, physicochemical and physiological comparison

A series of deletion mutants extending from -250 toward the capsite has been constructed in the early promoter region of the adenovirus 2 EIIa gene and tested both in vitro, and in vivo after transfection...Full Text Available

1983-10-25

94

Oxidation of an engineered pore cysteine locks a voltage-gated K+ channel in a nonconducting state.

1. The penicillinases formed by penicillinase-constitutive mutant strains from two closely related varieties (749 and 6346) of Bacillus licheniformis have been isolated, characterized...Full Text Available

1965-03-01

95

Mutations in cyr1 and pat1 reveal pheromone-induced G1 arrest in the fission yeast Schizosaccharomyces pombe

We report the use of cysteine-substituted mutants in conjunction with in situ oxidation to determine the physical proximity of a pair of engineered cysteines in the pore region of the voltage-gated...Full Text Available

1996-12-01

96

DEFF Research Database (Denmark)

Investigations into sexual differentiation and pheromone response in the fission yeast Schizosaccharomyces pombe are complicated by the need to first starve the cells of nitrogen. Most mating-related experiments are therefore performed on non-dividing cells. Here we overcome this problem by using two mutants that bypass the nutritional requirements and respond to the M-factor mating pheromone in rich medium. The first mutant lacks the cyr1 gene which encodes adenylate cyclase and these cells contain no measurable amounts of cAMP. When M-factor is added to a growing h+ cyr1- strain it causes a transient G1 arrest of cell division, transcription of mat1-Pm, and elongation of the cells to form shmoos. The second mutant contains the temperature-sensitive pat1-114 allele. At 30 degrees C this mutant was previously shown not only to bypass the nutritional signal but also to stop growing in a state derepressed ...

1994-01-01

97

Mutant ?-Synuclein Overexpression Mediates Early Proinflammatory Activity

Modulation of lipid biosynthesis contributes to stress resistance and longevity of C. elegans mutants

Microglia provide immune surveillance for the brain through both the removal of cellular debris and protection against infection by microorganisms and “foreign” molecules. Upon...Full Text Available

2009-10-01

98

Knockout of Arabidopsis ACCELERATED-CELL-DEATH11 encoding a sphingosine transfer protein causes activation of programmed cell death and defense

Many lifespan-modulating genes are involved in either generation of oxidative substrates and end-products, or their detoxification and removal. Among such metabolites, only lipoperoxides have the ability...Full Text Available

99

Isolation of an Escherichia coli K4 kfoC mutant over-producing capsular chondroitin

We describe the lethal, recessive accelerated-cell-death11 Arabidopsis mutant (acd11). Cell death in acd11 exhibits characteristics of animal apoptosis...Full Text Available

2002-02-15

100

Investigation and prediction of the severity of p53 mutants using parameters from structural calculations

BackgroundChondroitin sulphate is a complex polysaccharide having important structural and protective functions in animal tissues. Extracted from animals, this compound is used as...Full Text Available

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101

Identification of the Haemophilus influenzae tolC Gene by Susceptibility Profiles of Insertionally Inactivated Efflux Pump Mutants

A method has been developed to predict the effects of mutations in the p53 cancer suppressor gene. The new method uses novel parameters combined with previously established parameters. The most important...Full Text Available

2009-08-01

102

Identification of Potential Calorie Restriction-Mimicking Yeast Mutants with Increased Mitochondrial Respiratory Chain and Nitric Oxide Levels

Isogenic strains containing insertional disruptions of 10 Haemophilus influenzae Rd genes were investigated for their effects on the susceptibility of the organism to various classes...Full Text Available

2004-04-01

103

Identification and Disruption of Two Discrete Loci Encoding Hyaluronic Acid Capsule Biosynthesis Genes hasA, hasB, and hasC in Streptococcus uberis

Calorie restriction (CR) induces a metabolic shift towards mitochondrial respiration; however, molecular mechanisms underlying CR remain unclear. Recent studies suggest that CR-induced mitochondrial...Full Text Available

104

High-Throughput Screen for Poly-3-Hydroxybutyrate in Escherichia coli and Synechocystis sp. Strain PCC6803

The hyaluronic acid capsule of Streptococcus uberis has been implicated in conferring resistance to phagocytosis by bovine neutrophils. Construction of a bank of random insertion mutants...Full Text Available

2001-01-01

105

Gene-enzyme telationships in somatic cells and their organismal derivatives in higher plants. Progress report

A novel, quantitative method for detecting poly-3-hydroxybutyrate (PHB) amounts in viable cells was developed to allow for high-throughput screening of mutant libraries. The staining technique was demonstrated...Full Text Available

2006-05-01

106

Gene expression profiling of oxidative stress response of C. elegans aging defective AMPK mutants using massively parallel transcriptome sequencing

Progress is reported in the following subject areas: (1) chemistry of the arogenate molecule; (2) plant enzymology at the organismal level; (3) isolation of regulatory mutants in tobacco; and (4) stability of the haploid state in Nicotiana sylvestris.

1980-04-21

107

Developmental abnormalities and epimutations associated with DNA hypomethylation mutations.

BackgroundA strong association between stress resistance and longevity in multicellular organisms has been established as many mutations that extend lifespan also show increased...Full Text Available

108

Defects in the Secretory Pathway and High Ca²⁺ Induce Multiple P-bodies

A number of aberrant morphological phenotypes were noted during propagation of the Arabidopsis thaliana DNA hypomethylation mutant, ddm1, by repeated self-pollination. Onset of a spectrum of morphological...Full Text Available

1996-10-29

109

Cytokinin-Deficient Transgenic Arabidopsis Plants Show Multiple Developmental Alterations Indicating Opposite Functions of Cytokinins in the Regulation of Shoot and Root Meristem Activity

mRNA is sequestered and turned over in cytoplasmic processing bodies (PBs), which are induced by various cellular stresses. Unexpectedly, in Saccharomyces cerevisiae, mutants of the...Full Text Available

2010-08-01

110

Construction and Characterization of Genetically Defined aro omp Mutants of Enterotoxigenic Escherichia coli and Preliminary Studies of Safety and Immunogenicity in Humans

Cytokinins are hormones that regulate cell division and development. As a result of a lack of specific mutants and biochemical tools, it has not been possible to study the consequences of cytokinin...Full Text Available

2003-11-01

111

Construction and Application of a Zebrafish Array CGH Platform

Enterotoxigenic Escherichia coli (ETEC) is a leading cause of diarrhea in travelers to countries where the disease is endemic and causes a major disease burden in the indigenous population,...Full Text Available

2001-08-01

112

Comparative transcripts profiling reveals new insight into molecular processes regulating lycopene accumulation in a sweet orange (Citrus sinensis) red-flesh mutant

The zebrafish is emerging as a prominent model system for studying the genetics of human development and disease. Genetic alterations that underlie each mutant model can exist in the form of...Full Text Available

2009-02-01

113

Characterization of T-Even Bacteriophage Substructures

BackgroundInterest in lycopene metabolism and regulation is growing rapidly because accumulative studies have suggested an important role for lycopene in human health promotion....Full Text Available

114

Biochemical analysis of PIFTC3, the Trypanosoma brucei ortholog of nematode DYF-13, reveals interactions with established and putative intraflagellar transport components

Tail plates obtained from T4D amber mutants were examined with respect to sedimentation behavior, subunit molecular weights, amino acid composition, isoelectric points, and morphology. Intact plates...Full Text Available

1970-10-01

115

Behavioral consequences of dopamine deficiency in the Drosophila central nervous system

DYF-13, originally identified in C. elegans within a collection of dye-filling chemosensory mutants, is one of several proteins that have been classified as putatively involved...Full Text Available

2010-10-01

116

An Arabidopsis Mutant Resistant to Thaxtomin A, a Cellulose Synthesis Inhibitor from Streptomyces SpeciesW?

The neuromodulatory function of dopamine (DA) is an inherent feature of nervous systems of all animals. To learn more about the function of neural DA in Drosophila, we generated mutant...Full Text Available

2011-01-11

117

A new gene (alkB) of Escherichia coli that controls sensitivity to methyl methane sulfonate.

Thaxtomin A is a phytotoxin produced by Streptomyces scabies and other Streptomyces species, the causative agents of common scab disease in potato and other taproot...Full Text Available

2003-08-01

118

A Turquoise Mutant Genetically Separates Expression of Genes Encoding Phycoerythrin and Its Associated Linker Peptides

Seven mutants of Escherichia coli were isolated that are sensitive to methyl methane sulfonate but not to UV light. They exhibited decreased host cell reactivation capacity for methyl methane sulfonate-treated...Full Text Available

1983-03-01

119

Effect of ionizing radiation and chemical mutagens on vegetatively reproducing plants. Deistvie ioniziruyushchikh izluchenii i khimicheskikh mutagenov na vegetativno razmnozhaemye rasteniya

During complementary chromatic adaptation (CCA), cyanobacterial light harvesting structures called phycobilisomes are restructured in response to ambient light quality shifts. Transcription of genes...Full Text Available

2002-02-01

120

Antifungal activity of Glycyrrhiza glabra extracts and its active constituent glabridin

A study is made of plant sensitivity to mutagens during the processing of seeds. An examination is made of problems concerned with modification mutability, the nature of plant restoration following irradiation. Particular attention is given to mutation changes. A presentation is made of several features of mutant changes initially selected by separate indicators. An examination is made of the possible study of mutant indicator genetics. General data on the forms and varieties produced by the mutagenesis method are given. The book is designed for breeding specialists and geneticists engaged in the study of mutagenesis. 439 references, 27 figures, 66 table.

1981-01-01

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121

British Library Electronic Table of Contents (United Kingdom)

Glabridin, an active constituent of Glycyrrhiza glabra roots, was found to be active against both yeast and filamentous fungi. Glabridin also showed resistance modifying activity against drug resistant mutants of Candida albicans at a minimum inhibitory concentration of 31.25-250 g/mL. Although the compound was reported earlier to be active against Candida albicans, but this is the first report of its activity against drug resistant mutants. Copyright Copyright 2009 John Wiley & Sons, Ltd.

2009-01-01

122

The microbiology of forest soils: a literature review

Extended Spectrum ?-Lactamases among Gram-negative bacteria of nosocomial origin from an Intensive Care Unit of a tertiary health facility in Tanzania

This report discusses the activities of two major groups of forest soil microorganisms, the bacteria and the fungi. Special attention is paid to their participation in the decay of major forest litter substrates, including leaves, branches and roots. The influence of bacteria and fungi in symbiotic associations with woody plant roots upon the cycles of carbon and nitrogen is described. The impacts of certain forest mamagement alternatives are assessed in terms of the creation of elimination of suitable environments for the activity of soil microorganisms. A bibliography is included. 507 refs., 1 tab.

1982-01-01

123

Elucidating novel pathways and regulation of nitrogen assimilation in alpha proteobacteria exemplified by the soil organism Paracoccus denitrificans

BackgroundResistance to third generation cephalosporins due to acquisition and expression of extended spectrum β-lactamase (ESBL) enzymes among Gram-negative bacteria is...Full Text Available

124

Environmental Research Database

DescriptionThe importance of inorganic nitrate for the nutrition and growth of marine and freshwater autotrophic phytoplankton has long been recognised, in particularly because of the 'blooms' formed in nitrate and phosphate polluted water and their possible roles as carbon dioxide sinks. By contrast, the utilisation of nitrate by heterotrophic bacteria has historically received less attention. Up until now, the primary role of heterotrophic bacteria has classically been considered to be the decomposition [continued...

2010-01-31

125

Characteristics of CDC group 1 and group 1-like coryneform bacteria isolated from clinical specimens.

Development and application of microbial selective plugging processes

Fifteen strains of CDC group 1 coryneform and biochemically similar bacteria were isolated from clinical specimens. Of the 15 strains isolated, 11 were derived from abscesses and purulent lesions, mostly...Full Text Available

1993-11-01

126

Bactericidal effects of non-thermal argon plasma in vitro, in biofilms and in the animal model of infected wounds.

Phillips Petroleum Company recently completed a microbial selective plugging (MSP) pilot at the North Burbank Unit (NBU), Shidler, Oklahoma. Nutrients were selected for the pilot that could stimulate indigenous microflora in the reservoir brine to grow and produce exopolymer. It was found that soluble corn starch polymers (e.g., maltodextrins) stimulated the indigenous bacteria to produce exopolymer, whereas simple sugars (e.g., glucose and sucrose), as well as complex media (e.g., molasses and Nutrient Broth), did not. Injection of maltodextrin into rock cores in the presence of indigenous NBU bacteria resulted in stable permeability reductions (> 90%) across the entire length, while injection of glucose resulted only in face plugging. In addition, it was found that organic phosphate esters (OPE) served as a preferable source of phosphorus for the indigenous bacteria, since orthophosphates and condensed phosphates ...

1995-12-31

127

Use of radiosensitivity to identify irradiated fresh poultry products

Non-thermal (low-temperature) physical plasma is under intensive study as an alternative approach to control superficial wound and skin infections when the effectiveness of chemical agents is weak due to natural pathogen or biofilm resistance. The purpose of this study was to test the individual susceptibility of pathogenic bacteria to non-thermal argon plasma and to measure the effectiveness of plasma treatments against bacteria in biofilms and on wound surfaces. Overall, Gram-negative bacteria were more susceptible to plasma treatment than Gram-positive bacteria. For the Gram-negative bacteria Pseudomonas aeruginosa, Burkholderia cenocepacia and Escherichia coli, there were no survivors among the initial 10(5) c.f.u. after a 5 min plasma treatment. The susceptibility of Gram-positive bacteria was species- and strain-specific. Streptococcus pyogenes was the ...

2010-09-09

128

Strength and stability of microbial plugs in porous media

Microbiological comparison between irradiated and non-irradiated foodstuff has been studied for a long time as a way to detect whether a foodstuff has been irradiated or not. Generally, the proposed methods are based on the fact that ionization select species of bacteria which are recognized to be radioresistant. So reduction or elimination of known radiation sensitive microbes from the normal endogenous microflora could give an indication that the foodstuff has been irradiated, predominance of known radioresistant bacteria should be another indication. In the present work, we try to develop a test based on the radiosensitivity of the bacteria independently of their place. These first experiments show that the determination of radiosensitivity of strains isolated from a product or even of global radioresistance of mesophilic microflora could indicate if this product has been previously submitted to ionizing radiations. (4 ...

1990-02-14

129

PREPARATION AND PROPERTIES OF ANTIBACTERIAL ALGINATE FILMS INCORPORATING EXTRUDED WHITE GINSENG EXTRACT

Mobility reduction induced by the growth and metabolism of bacteria in high-permeability layers of heterogeneous reservoirs is an economically attractive technique to improve sweep efficiency. This paper describes an experimental study conducted in sandpacks using an injected bacterium to investigate the strength and stability of microbial plugs in porous media. Successful convective transport of bacteria is important for achieving sufficient initial bacteria distribution. The chemotactic and diffusive fluxes are probably not significant even under static conditions. Mobility reduction depends upon the initial cell concentrations and increase in cell mass. For single or multiple static or dynamic growth techniques, permeability reduction was approximately 70% of the original permeability. The stability of these microbial plugs to increases in pressure gradient and changes in cell physiology in a nutrient-depleted ...

1995-12-31

130

British Library Electronic Table of Contents (United Kingdom)

Abstract Preparation of antibacterial alginate films incorporating extruded white ginseng (EWG) extracts was attempted. The antibacterial effect of EWG extract on six selected food pathogenic bacteria was compared with the effect of red ginseng (RG) and white ginseng (WG) extracts. The EWG was processed in a twin-screw extruder with feed moisture of 20% and barrel temperature of 115 and 130C. The data obtained by agar diffusion assay demonstrated that the film containing 1-g/mL of EWG at barrel temperatures of 115 (EWG-115) and 130C (EWG-130) exhibited stronger antibacterial activity against the four strains of bacteria than the other extracts RG and WG. All films sampled showed reduction in bacteria cell counts (log cycle) compared with the control. After 24-h of incubation, Pseudomonas a...

2011-01-01

131

Optimal conditions for stability of photoemission and freeze drying of two luminescent bacteria for use in a biosensor

British Library Electronic Table of Contents (United Kingdom)

Abstract Bioluminescent bacteria have been used for many years for biotoxicological analysis. One of the main concerns with this microorganism is the low experimental repeatability when subjected to external factors. The aim of the present study was to obtain accurate, sensitive, and repeatable measurements with stable signals (during the detection and over days) for application in a water-analysis device for the detection of pollutants. Growth conditions were tested and optimized. An optimal freeze-drying procedure for the constitutive bioluminescent bacteria Vibrio fischeri and Photobacterium phosphoreum was developed. The luminescence stability after rehydration was also investigated. Freeze drying was found to be a critical process in survival and signal stability of luminescent bacter...

2011-01-01

132

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

Decolorization of textile azo dyes by newly isolated halophilic and halotolerant bacteria

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

1999-12-01

133

British Library Electronic Table of Contents (United Kingdom)

Studies were carried out on the decolorization of textile azo dyes by newly isolated halophilic and halotolerant bacteria. Among the 27 strains of halophilic and halotolerant bacteria isolated from effluents of textile industries, three showed remarkable ability in decolorizing the widely utilized azo dyes. Phenotypic characterization and phylogenetic analysis based on 16S rDNA sequence comparisons indicate that these strains belonged to the genus Halomonas. The three strains were able to decolorize azo dyes in a wide range of NaCl concentration (up to 20%w/v), temperature (25-40degreeC), and pH (5-11) after 4 days of incubation in static culture. They could decolorize the mixture of dyes as well as pure dyes. These strains also readily grew in and decolorized the high concentrations of dy...

2007-01-01

134

biotechnological studies on the effect of gamma rays on peanut

Radiation effects on shoot tip culture of chrysanthemum, 2

local peanut cultivars Giza 4 and Giza 5 were exposed to different doses ( 50,100,150,200,250 and 300 Gy)to Co "6"0 gamma ray source . all irradiated materials were cultivated to give the M_1 and M_2 generation , then high yielding mutants were selected from the M_2 generation and cultivated separately to give the M_3 generation. some yield component traits were measured for the three generations (M_1,M_2 and M_3) and M_3 families.variations observed in these traits were attributed to genetic factors. the M_3 selected mutants were artificially infected by aspergillus flavus L spores (aflatoxins-B1 and B2 groups-producer strain). aflatoxin concentrations were estimated and the analysis showed that aflatoxin concentrations in seeds of the M_3 selected mutants from cultivar Giza 4 were higher than those in seeds of the M3 mutants selected from cultivar Giza 5. however, the concentration of aflatoxin ...

2007-01-01

135

Effect of mutations in HNF-1#alpha# and HNF-1#beta# on the transcriptional regulation of human sucrase-isomaltase in Caco-2 cells

(1) Young chrysanthemums were planted after being irradiated at the time of shoot tip culture and the influence of irradiation was evaluated from the point of view of establishment of mutants. (2) Two cultivars, Kin-tenryu and Tenryu-no-asa were used in this experiment. The percentage of cultivars healthy enough to transplant on June 10, 1972 showed a decrease in proportion to the increase of dosage. Some plants of cultivar Kin-tenryu died after being transplanted. (3) Few plants of either cultivar could overwinter, and in particular no plant irradiated by gamma-rays of 20 kR. (4) Plant height showed a tendency of inhibition in both cultivars. (5) Three chlorophyll mutants showing chimera appeared. One of them was in the cultivar Tenryu-no-asa irradiated by 10 kR at 3 days after planting; two of them were in the cultivar Tenryu-no-asa irradiated by 10 kR at 5 days after planting. One mutant exhibiting malformation of entire ...

136

Detection of basepair substitution mutation at a frequency of 1 x 10(-7) by combining two genotypic selection methods, MutEx enrichment and allele-specific competitive blocker PCR.

Mutations in transcription factors hepatocyte nuclear factors (HNF)-1#alpha# and HNF-1#beta# cause maturity-onset diabetes of the young (MODY) types 3 and 5, respectively. HNF-1#alpha# and HNF-1#beta# mutations are well studied in some tissues, but the mechanism by which HNF-1#alpha# and HNF-1#beta# mutations affect sucrase-isomaltase (SI) transcription in the small intestine is unclear. We studied the effects of 13 HNF-1#alpha# mutants and 2 HNF-1#beta# mutants on human SI gene transcription, which were identified in subjects with MODY3 and MODY5, respectively. Transactivation activity of 11 HNF-1#alpha# and 2 HNF-1#beta# mutants was significantly lower than that of wild (wt)-HNF-1#alpha# and wt-HNF-1#beta#. Furthermore, in co-expression studies with mutant (mu)-HNF-1#alpha#/ wt-HNF-1#beta# and wt-HNF-1#alpha#/mu-HNF-1#beta#, the combination of mu-HNF-1#alpha# (P379fsdelCT and ...

2004-12-03

137

Vancomycin-resistant Enterococcus domination of intestinal microbiota is enabled by antibiotic treatment in mice and precedes bloodstream invasion in humans

The detection of rare mutations has many important applications, including risk assessment of drugs and chemicals, measuring environmental exposures to genotoxins, and cancer cell detection. A sensitive genotypic selection method has been developed that combines two different mutant allele selection techniques, MutEx enrichment and allele-specific competitive blocker PCR (ACB-PCR). This method was developed and evaluated for the detection of a CAA --> AAA mutation at codon 61 of the mouse H-ras gene. The MutEx enrichment is based on MutS binding to a mismatched basepair in heteroduplex DNA. The bound MutS protects the mutant allele from degradation during subsequent exonuclease treatment. ACB-PCR preferentially amplifies a mutant allele in a PCR reaction using a primer that has more mismatches to the wild-type allele than the mutant allele. By combining these two approaches, the codon 61 mutation was ...

1998-01-01

138

USGS Water-Quality Information: Fecal Indicator Bacteria

Bloodstream infection by highly antibiotic-resistant bacteria, such as vancomycin-resistant Enterococcus (VRE), is a growing clinical problem that increasingly defies medical intervention....Full Text Available

2010-12-01

139

Type IVB Secretion Systems of Legionella and Other Gram-Negative Bacteria

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2011-08-27

140

Toxic Effects of Linear Alkylbenzene Sulfonate on Metabolic Activity, Growth Rate, and Microcolony Formation of Nitrosomonas and Nitrosospira Strains

Type IV secretion systems (T4SSs) play a central role in the pathogenicity of many important pathogens, including Agrobacterium tumefaciens, Helicobacter pylori, and...Full Text Available

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141

The prosthetic group of methanol dehydrogenase. Purification and some of its properties.

Strong inhibitory effects of the anionic surfactant linear alkylbenzene sulfonate (LAS) on four strains of autotrophic ammonia-oxidizing bacteria (AOB) are reported. Two Nitrosospira...Full Text Available

2001-06-01

142

The efflux of a fluorescent probe is catalyzed by an ATP-driven extrusion system in Lactococcus lactis.

Methanol dehydrogenases isolated from bacteria belonging to different classes of methylotrophs contain the same prosthetic group. A procedure for its purification from whole cells is given. The reduced...Full Text Available

1980-04-01

143

The control of sulphate reduction in bacteria

Many bacteria, both gram positive and gram negative, extrude in an energy-dependent manner the fluorescent pH indicator 2',7'-bis-(2-carboxyethyl)-5[and -6]-carboxyfluorescein (BCECF) (D. Molenaar,...Full Text Available

1992-05-01

144

The bacterial signal indole increases epithelial-cell tight-junction resistance and attenuates indicators of inflammation

1. An enzyme from Escherichia coli 9723 that reduces adenosine 3′-phosphate 5′-sulphatophosphate to inorganic sulphite is described. Extracts of E. coli...Full Text Available

1965-07-01

145

The RNA Chaperone Hfq Is Important for Growth and Stress Tolerance in Francisella novicida

Interkingdom signaling is established in the gastrointestinal tract in that human hormones trigger responses in bacteria; here, we show that the corollary is true, that a specific bacterial signal,...Full Text Available

2010-01-05

146

The Pseudomonas aeruginosa PA01 Gene Collection

The RNA-binding protein Hfq is recognized as an important regulatory factor in a variety of cellular processes, including stress resistance and pathogenesis. Hfq has been shown in several bacteria to...Full Text Available

147

Surprising Alteration of Antibacterial Activity of 5?-Modified Neomycin against Resistant Bacteria

Pseudomonas aeruginosa, a common inhabitant of soil and water, is an opportunistic pathogen of growing clinical relevance. Its genome, one of the largest among bacteria [5570 open reading...Full Text Available

2004-10-01

148

Succession of Indigenous Pseudomonas spp. and Actinomycetes on Barley Roots Affected by the Antagonistic Strain Pseudomonas fluorescens DR54 and the Fungicide Imazalil

A facile synthetic protocol for the production of neomycin B derivatives with various modifications at the 5″ position has been developed. Structural activity relationship (SAR) against...Full Text Available

2008-12-11

149

Structural basis of ligand binding by a c-di-GMP riboswitch

In recent years, the interest in the use of bacteria for biological control of plant-pathogenic fungi has increased. We studied the possible side effects of coating barley seeds with the antagonistic...Full Text Available

2001-03-01

150

Sex and space destabilize intransitive competition within and between species

The second messenger signaling molecule bis-(3′-5′)-cyclic dimeric guanosine monophosphate (c-di-GMP) regulates many processes in bacteria, including motility, pathogenesis,...Full Text Available

2009-12-01

151

Self-Chaperoning of the Type III Secretion System needle tip proteins IpaD and BipD

Organisms ranging from bacteria and corals to plants and vertebrates can form intransitive competitive networks, in which coexistence can be maintained because no one species or genotype is superior...Full Text Available

2008-08-22

152

Pseudomonas aeruginosa selective adherence to and entry into human endothelial cells.

Bacteria expressing type III secretion systems (T3SS) have been responsible for the deaths of millions worldwide, acting as key virulence elements in diseases ranging from plague to typhoid...Full Text Available

2007-02-09

153

Primary structure and regulation of vegetative specific genes of Dictyostelium discoideum.

The pathogenesis of Pseudomonas aeruginosa disseminated infections depends on bacterial interaction with blood vessels. We have hypothesized that in order to traverse the endothelial barrier, bacteria...Full Text Available

1994-12-01

154

Preterm low birthweight and the role of oral bacteria

We have examined the expression and structure of several genes belonging to two classes of vegetative specific genes of the simple eukaryote, Dictyostelium discoideum. In amebae grown on bacteria, deactivation...Full Text Available

1989-12-11

155

Physiological Adaptation of a Nitrate-Storing Beggiatoa sp. to Diel Cycling in a Phototrophic Hypersaline Mat?

Preterm and low birthweight (PTLBW) continues to be a major cause of mortality and morbidity across the world. In recent years, maternal periodontal disease has been implicated as a risk factor for...Full Text Available

156

PCR-based method for targeting 16S-23S rRNA intergenic spacer regions among Vibrio species

The aim of this study was to investigate the supposed vertical diel migration and the accompanying physiology of Beggiatoa bacteria from hypersaline microbial mats. We combined microsensor,...Full Text Available

2007-11-01

157

On Being the Right Size: The Impact of Population Size and Stochastic Effects on the Evolution of Drug Resistance in Hospitals and the Community

BackgroundThe genus Vibrio is a diverse group of Gram-negative bacteria comprised of 74 species. Furthermore, the genus has and is expected to continue expanding...Full Text Available

158

Occurrence of fecal indicator bacteria in surface waters and the subsurface aquifer in Key Largo, Florida.

The evolution of drug resistant bacteria is a severe public health problem, both in hospitals and in the community. Currently, some countries aim at concentrating highly specialized services in large...Full Text Available

2011-04-01

159

Mutagenic and cytotoxic activity of doxorubicin and daunorubicin derivatives on prokaryotic and eukaryotic cells.

Sewage waste disposal facilities in the Florida Keys include septic tanks and individual package plants in place of municipal collection facilities in most locations. In Key Largo, both facilities discharge...Full Text Available

1995-06-01

160

Name of Presentation!

Wastenet

Up-flow anaerobic attached-growth bioreactors filled with pre-treated coir fibres ...coir-fibre arranged in bottle-brush configuration bounded by a novel plastic binding technique ...-three anaerobic filter reactors in series -coir fibre as the bacteria growth media a sedimentation

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161

Molecular biological enhancement of coal biodesulfurization. Final report, October 1988--December 1991

The mutagenic and cytotoxic activity of two newly synthesized doxorubicin derivatives and of one daunorubicin derivative were studied in V79 Chinese hamster cells and bacteria (Salmonella typhimurium...Full Text Available

1984-07-01

162

Microbial indicators of environmental water pollution. Mizu kankyo ni okeru biseibutsu shihyo

The overall objective of this project was to use molecular genetics to develop strains of bacteria with enhanced ability to remove sulfur from coal, and to obtain data that will allow the performance and economics of a coal biodesulfurization process to be predicted. (VC)

1991-12-01

163

Isolation and characterization of a novel gamma-hexachlorocyclohexane-degrading bacterium.

Microbial indicators in the environmental water are categorized as follows. 1. Index for pathogenic microbial contamination, especially enteric canal based ones. 2. Index for the ordinary microbial contamination. 3. Index for nutritive assessment. 4. Index for the treating effect of final effluent discharged into an environmental water. 5. Index for distinction of of the contamination source. Above 1 and 2'' are among the indices which cannot be replaced by other physico-chemical substances or indices. Up to the present time, 1'' is assessed by a coliform group and 2'' by the bacteria. Recently, however, the status on the microbial contamination of the environmental water is changing, thus urging the reexamination of the assessment systems. This report describes the following items. Characteristics and the elements of the indices (enteric canal based pathogenic microbial contamination); indices under examination ...

1990-08-10

164

Induction of autolysis in nongrowing Escherichia coli.

The natural biotic capacity of soils to degrade gamma-hexachlorocyclohexane (gamma-HCH, lindane) was estimated using an enrichment technique based on the ability of soil bacteria to develop on synthetic...Full Text Available

1996-10-01

165

Identification of CTX-M-Type Extended-Spectrum-?-Lactamase Genes Using Real-Time PCR and Pyrosequencing?

Unless relaxation of the stringent response is achieved, all nongrowing bacteria rapidly develop resistance to autolysis induced by a variety of agents, including all classes of cell wall synthesis...Full Text Available

1986-09-01

166

Heavy metals alter the electrokinetic properties of bacteria, yeasts, and clay minerals.

CTX-M extended-spectrum β-lactamases (ESBLs) are increasingly prevalent worldwide among Escherichia coli bacteria, mostly in community-acquired urinary tract infections. Finding...Full Text Available

2007-01-01

167

Gingival crevicular fluid levels of clindamycin compared with its minimal inhibitory concentrations for periodontal bacteria.

The electrokinetic patterns of four bacterial species (Bacillus subtilis, Bacillus megaterium, Pseudomonas aeruginosa, and Agrobacterium radiobacter), two yeasts (Saccharomyces cerevisiae and Candida...Full Text Available

1992-05-01

168

Generation of Novel Bacterial Regulatory Proteins That Detect Priority Pollutant Phenols

Clindamycin concentrations in gingival crevicular fluid and in blood were determined over a 7-h period and were related to the minimal inhibitory concentrations of this agent for 340 bacterial strains...Full Text Available

1981-05-01

169

Evolutionary Trajectories of Beta-Lactamase CTX-M-1 Cluster Enzymes: Predicting Antibiotic Resistance

The genetic systems of bacteria that have the ability to use organic pollutants as carbon and energy sources can be adapted to create bacterial biosensors for the detection of industrial pollution....Full Text Available

2000-01-01

170

Epidemiological Risk Factors for Isolation of Ceftriaxone-Resistant versus -Susceptible Citrobacter freundii in Hospitalized Patients

Extended-spectrum beta-lactamases (ESBL) constitute a key antibiotic-resistance mechanism affecting Gram-negative bacteria, and also an excellent model for studying evolution in real time. A shift in...Full Text Available

2010-01-01

171

Endometrial biopsy in Holstein-Friesian dairy cows. III. Bacteriological analysis and correlations with histological findings.

Antimicrobial resistance is an emerging problem among nosocomial bacteria. Risk factors for the recovery of ceftriaxone-resistant (CRCF) or -susceptible (CSCF) Citrobacter freundii...Full Text Available

2003-09-01

172

Endogenous Nitric Oxide Protects Bacteria Against a Wide Spectrum of Antibiotics

This study examines the results of bacterial culture from 159 endometrial biopsy samples from 97 commercial dairy cows and correlations between bacteriological and histological findings. Bacteria were...Full Text Available

1991-04-01

173

Effect of clindamycin on neutrophil killing of gram-negative periodontal bacteria.

Bacterial nitric oxide synthases (bNOS) are present in many Gram-positive species and have been demonstrated to synthesize NO from arginine in vitro and in vivo. However, the physiological role...Full Text Available

2009-09-11

174

Effect of Length of Time before Incorporation on Survival of Pathogenic Bacteria Present in Livestock Wastes Applied to Agricultural Soil

Periodontal diseases are infections of the tissues supporting the dentition. Recognition that relatively specific microfloras are associated with distinct clinical forms of periodontal disease has prompted...Full Text Available

1988-10-01

175

Dynamics of Microbial Communities on Marine Snow Aggregates: Colonization, Growth, Detachment, and Grazing Mortality of Attached Bacteria

In response to reports that the contamination of food can occur during the on-farm primary phase of food production, we report data that describes a possible cost-effective intervention measure. The...Full Text Available

2004-09-01

176

Distribution Frequency of Pathogenic Bacteria Isolated from Cutaneus Leishmaniasis Lesions

We studied the dynamics of microbial communities attached to model aggregates (4-mm-diameter agar spheres) and the component processes of colonization, detachment, growth, and grazing mortality. Agar...Full Text Available

2003-06-01

177

Cyclic Diguanylate Signaling Proteins Control Intracellular Growth of Legionella pneumophila

Cutaneous leishmaniasis (CL) is a parasitic disease characterized by single or multiple ulcerations. Secondary bacterial infections are one of the complications that can increase the tissue destruction...Full Text Available

2008-09-01

178

Critical superparamagnetic/single-domain grain sizes in interacting magnetite particles: implications for magnetosome crystals

Proteins that metabolize or bind the nucleotide second messenger cyclic diguanylate regulate a wide variety of important processes in bacteria. These processes include motility, biofilm formation, cell...Full Text Available

179

Coryneform bacteria in infectious diseases: clinical and laboratory aspects.

Magnetotactic bacteria contain chains of magnetically interacting crystals (magnetosome crystals), which they use for navigation (magnetotaxis). To improve magnetotaxis efficiency, the magnetosome crystals...Full Text Available

2009-12-06

180

Comparison of maintenance energy expenditures and growth yields among several rumen bacteria grown on continuous culture.

Coryneform isolates from clinical specimens frequently cannot be identified by either reference laboratories or research laboratories. Many of these organisms are skin flora that belong to a large number...Full Text Available

1990-07-01

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181

Comparative in vitro activity of Meropenem, Imipenem and Piperacillin/tazobactam against 1071 clinical isolates using 2 different methods: a French multicentre study

Maintenance energy expenditures were mesured for five rumen bacteria, Selenomonas ruminantium, Butyrivibrio fibrisolvens, Bacteroides ruminicola, Megasphaera elsdenii, and Streptococcus bovis, by using a complex medium with glucose as the carbon source. Large differences (as high as 8.5-fold) in maintenance energy expenditures were seen among these bacteria. The suggestion is made that maintenance requirements could be a significant determinant of bacterial competition in the rumen. Theoretical maximum growth yields, calculated from double reciprocal plots of yield versus dilution rate, were compared to theoretical Y(ATP) values in order to estimate minimum molar adenosine 5'-triphosphate yields from glucose for each bacterium. Results showed that relative yield among the bacteria was growth rate dependent. At high dilution rates, both S. ruminantium and S. bovis produced lactate as their principal fermentation product. At ...

1979-03-01

182

Comparative genomics reveals 104 candidate structured RNAs from bacteria, archaea, and their metagenomes

BackgroundMeropenem is a carbapenem that has an excellent activity against many gram-positive and gram-negative aerobic, facultative, and anaerobic bacteria. The major objective...Full Text Available

183

Community Structure of Ammonia-Oxidizing Bacteria within Anoxic Marine Sediments

BackgroundStructured noncoding RNAs perform many functions that are essential for protein synthesis, RNA processing, and gene regulation. Structured RNAs can be detected by comparative...Full Text Available

2010-01-01

184

Cloning of an insecticidal cholesterol oxidase gene and its expression in bacteria and in plant protoplasts.

The potential for oxidation of ammonia in anoxic marine sediments exists through anaerobic oxidation by Nitrosomonas-like organisms, utilizing nitrogen dioxide, coupling of nitrification,...Full Text Available

2003-03-01

185

Cloning and expression of portions of the 34-kilodalton-protein gene of Mycobacterium paratuberculosis: its application to serological analysis of Johne's disease.

We cloned and sequenced structural gene choM, which encodes an insecticidally active cholesterol oxidase in Streptomyces sp. strain A19249. The primary translation product was predicted to be a 547-amino-acid...Full Text Available

1994-12-01

186

Chemical and biological monitoring of MIOR on the pilot area of Vyngapour oil field, West Sibera, Russia

Paratuberculosis (Johne's disease), an endemic mycobacteriosis of cattle that is caused by Mycobacterium paratuberculosis, is characterized by incoercible diarrhea and fecal shedding of bacteria. The...Full Text Available

1993-04-01

187

Characterization of Airborne Microbial Communities at a High-Elevation Site and Their Potential To Act as Atmospheric Ice Nuclei?

The pilot area of the Vyngapour oil field allotted for MIOR tests contains three injection and three producing wells. These wells were treated in summer 1993 and 1994. Before, during, and after MIOR treatments on the pilot area the chemical compounds of injected and formation waters were studied, as well as the amount and species of microorganisms entering the stratum with the injected water and indigenous bacteria presented in bottomhole zones of the wells. The results of monitoring showed that the bottomhole zone of the injection well already had biocenosis of heterotrophic, hydrocarbon-oxidizing, methanogenic, and sulfate-reducing bacteria, which were besides permanently introduced into the reservoir during the usual waterflooding. The nutritious composition activated vital functions of all bacterial species presented in the bottomhole zone of the injection well. The formation waters from producing wells showed the increase of the content of ...

1995-12-31

188

Changes in Tetracycline Susceptibility of Enteric Bacteria following Switching to Nonmedicated Milk Replacer for Dairy Calves?

Bacteria and fungi are ubiquitous in the atmosphere. The diversity and abundance of airborne microbes may be strongly influenced by atmospheric conditions or even influence atmospheric conditions themselves...Full Text Available

2009-08-01

189

Buoyant Densities and Dry-Matter Contents of Microorganisms: Conversion of a Measured Biovolume into Biomass

A randomized intervention study was conducted to determine if discontinuing use of calf milk replacer medicated with oxytetracycline results in increased tetracycline susceptibility in Salmonella...Full Text Available

2008-06-01

190

Attachment Stimulates Exopolysaccharide Synthesis by a Bacterium

Several isolates of bacteria and fungi from soil, together with cells released directly from soil, were studied with respect to buoyant density and dry weight. The specific volume (cubic centimeters...Full Text Available

1983-04-01

191

Association of Nasophyaryngeal Bacterial Colonization during Upper Respiratory Tract Infection and the Development of Acute Otitis Media

This study examined the hypothesis that solid surfaces may stimulate attached bacteria to produce exopolymers. Addition of sand to shake-flask cultures seemed to induce exopolymer synthesis by a number...Full Text Available

1993-10-01

192

Antimicrobial susceptibilities of bacteria associated with periodontal disease.

Acute Otitis Media occurs mostly after upper respiratory tract infection; the causative bacteria are those colonized in the nasopharynx. We studied 709 URI episodes and found that children with...Full Text Available

2008-02-15

193

Analysis of the Sulfate-Reducing Bacterial and Methanogenic Archaeal Populations in Contrasting Antarctic Sediments

A total of 193 bacterial strains were tested for their susceptibilities to 14 antimicrobial agents. Penicillin G was active at 2 U/ml against 98% of the oral isolates. Other antibiotics with good activity...Full Text Available

1983-03-01

194

Analysis of genomic differences among Clostridium botulinum type A1 strains

The distribution and activity of communities of sulfate-reducing bacteria (SRB) and methanogenic archaea in two contrasting Antarctic sediments were investigated. Methanogenesis dominated in freshwater...Full Text Available

2003-06-01

195

Aggregation Substance Promotes Adherence, Phagocytosis, and Intracellular Survival of Enterococcus faecalis within Human Macrophages and Suppresses Respiratory Burst

BackgroundType A1 Clostridium botulinum strains are a group of Gram-positive, spore-forming anaerobic bacteria that produce a genetically, biochemically, and biophysically...Full Text Available

196

Activity of Four Cephalosporin Antibiotics In Vitro Against Bovine Udder Pathogens and Pathogenic Bacteria Isolated from Newborn Calves

The aggregation substance (AS) of Enterococcus faecalis, encoded on sex pheromone plasmids, is a surface-bound glycoprotein that mediates aggregation between bacteria thereby facilitating...Full Text Available

2000-09-01

197

ADP-Glucose Pyrophosphorylase, a Regulatory Enzyme for Bacterial Glycogen Synthesis

The in vitro activity of chephaloridine, cephalexin, cefatrizine (BL-S640), and cephapirin (BL-P-1322) was evaluated by the serial dilution method against pathogenic gram-positive and gram-negative...Full Text Available

1976-03-01

198

A survey of the sensitivity of fresh clinical isolates to cefuroxime and other antibiotics.

The accumulation of α-1,4-polyglucans is an important strategy to cope with transient starvation conditions in the environment. In bacteria and plants, the synthesis of glycogen and starch occurs...Full Text Available

2003-06-01

199

A small RNA promotes siderophore production through transcriptional and metabolic remodeling

The sensitivities to cefuroxime and cephradine of potentially pathogenic bacteria isolated in two British general hospitals comprising 900 beds have been assessed. In a three-month period 2537 strains...Full Text Available

1979-09-01

200

A role of ygfZ in the Escherichia coli response to plumbagin challenge

Siderophores are essential factors for iron (Fe) acquisition in bacteria during colonization and infection of eukaryotic hosts, which restrain iron access through iron-binding protein, such as lactoferrin...Full Text Available

2010-08-24

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201

Replacement of leucine-93 by alanine or threonine slows down the decay of the N and O intermediates in the photocycle of bacteriorhodopsin: Implications for proton uptake and 13-cis-retinal----all-trans-retinal reisomerization

Plumbagin is found in many herbal plants and inhibits the growth of various bacteria. Escherichia coli strains are relatively resistant to this drug. The mechanism of resistance is...Full Text Available

202

Mitochondrial genetic damage induced in yeast by a photoactivated furocoumarin in combination with ethidium bromide or ultraviolet light

The authors report that the replacement of Leu-93 in bacteriorhodopsin by Ala (L93A) or Thr (L93T) slows down the photocycle by approximately 100-fold relative to wild-type bacteriorhodopsin. Time-resolved visible absorption spectroscopy and resonance Raman experiments, respectively, show the presence of long-lived O-like and N-like intermediates in the photocycles of the above mutants. We infer the existence of an equilibrium between the N and O intermediates in the photocycles of these mutants. The L93A and L93T mutants exhibit normal proton pumping under continuous illumination, suggesting that the decay of the N and/or O intermediate, and consequently, proton translocation, can be accelerated by the absorption of a second photon. Since the 13-cis----all-trans reisomerization of retinal is completed during the decay of the N and O intermediates, they conclude that the interaction of Leu-93 with retinal is important in ...

1991-08-01

203

Characterization of a novel missense mutation on murine Pax3 through ENU mutagenesis.

Ethidium bromide (EB) and ultraviolet light (UV) in combination are known to produce a synergistic induction of 'petite' mutants in yeast. Two other agents were combined with EB, 3-Carbethoxypsoralene (3 CPs) activated by 365 nm light or #gamma# rays. EB in combination with 3 CPs also resulted in an enhanced production of 'petite' mutants. After the photoaddition of 3 CPs in exponential phase cells, recovery of the 'petite' mutation during dark liquid holding was inhibited by the presence of EB producing an enhanced number of 'petite' mutants. The behavior of mitochondrial antibiotic resistance markers after individual and combined treatments with EB and 3 CPs indicates a random loss of markers after EB and a preferential loss of a certain region for the 3 CPs photoaddition. The combination of the two agents leads to an additivity of total drug marker losses rather than a synergistic loss. The combination of EB with #gamma# ...

204

6-Methyl-1,2,4-benzenetriol, a new intermediate in penicillic acid biosynthesis in Penicillium cyclopium

N-ethyl-N-nitrosourea (ENU) mutagenesis has led to the elucidation of several regulator genes for melanocyte and skin development. Here we characterized a mutant from ENU mutagenesis with similar phenotype as that of Splotch mutant, including exencephaly, spina bifida and abnormal limbs in homozygotes as well as white belly spotting and occasionally loop-tail in heterozygotes. This novel mutant was named as Sp(xG). Through genome-wide linkage analysis in backcross progenies with microsatellite markers, the Sp(xG) was confined to a region between D1MIT415 and D1MIT7 on chromosome 1, where notable Pax3 gene was located. Direct sequencing revealed that Sp(xG) carried a nucleotide A894G missense transition in exon 6 of Pax3 gene that resulted in Asn to Asp substitution at amino acid 269 within the highly-conserved homeodomain (HD) DNA recognition module, which was the first point mutation found in this domain in mice. This ...

2011-07-19

205

Rapid preparation of pyrogen-free 2H2(18)O for human-nutrition studies

Penicillic acid-negative mutants were obtained from a color mutant derived from Penicillium cyclopium NRRL 1888 through N-methyl-N'-nitro-N-nitrosoguanidine treatment. One mutant (SK2N6) accumulated 6-methyl-1,2,4-benzenetriol, which was not previously known to be a metabolite of P. cyclopium, in addition to orsellinic acid and orcinol. The radioactivity of [1-"1"4C]acetic acid was rapidly incorporated into 6-methyl-1,2,4-benzenetriol in a culture of P. cyclopium SK2N6. Moreover, the radioactivity of ["1"4C]6-methyl-1,2,4-benzenetriol was efficiently incorporated into penicillic acid in a culture of P. cyclopium NRRL 1888. These data indicate that 6-methyl-1,2,4-benzenetriol is a precursor for penicillic acid biosynthesis. The results on the addition of 1,4-dihydroxy-6-methoxy-2-methylbenzene, 6-methoxy-2-methylbenzoquinone (1,4), and 1-O-methylorcinol to a culture of P. cyclopium SK2N6 indicated that only the former two ...

206

One-dimensional free boundary problem for actin-based propulsion of Listeria

We describe a compact ultrafiltration system for the removal of pyrogens and bacteria from water labeled with the stable isotopes of deuterium and oxygen-18. The ultrafiltration system is constructed from readily available commercial components and can achieve complete removal of pyrogens and bacteria from 1L contaminated water within 30 min. By use of our procedure, loss of the isotopically labeled water by retention in the filtration system was minimal. The purified water is suitable for both oral and intravenous administration to healthy human subjects participating in nutrition studies.

207

Effect of microwaves on microorganisms in foods

Some bacteria move inside cells by recruiting the actin filaments of the host cells. The filaments are polymerized at the back surface of the bacteria, and they move away, forming a "comet" tail behind the bacterium, which consists of gel network. We develop a one-dimensional mathematical model of the gel based on partial differential equations which involve the number of filaments, the density and velocity of the gel, and the pressure. The two end-points of the gel form two free boundaries. The resulting free boundary problem is rather non-standard. We prove local existence and uniqueness.

2007-04-01

208

Characterisation of anti-Staphylococcus aureus activity of quercetin

The microbial safety of foods cooked in microwave ovens was investigated. The mechanisms of microwave destruction of microorganisms were examined. Effects of time and temperature on microorganisms in different food systems were described. Studies showed that: microwave heating of food is more ''''food dependent'' than conventional heating; recommended microwave treatment time for some foods may not destroy high levels of bacteria; use of microwaves in combination with conventional heating methods results in more uniform heating of foods and destruction of bacteria; and microwaves exert different killing effects on individual bacterial species. (78 references, 2 tables)

1980-08-01

209

British Library Electronic Table of Contents (United Kingdom)

Summary Although many antibiotics are available for the treatment of bacterial infections, the emergence and global spread of antibiotic-resistant bacteria is a community-wide problem. To overcome this problem, we must explore alternative antimicrobials. This study investigated the antibacterial properties of quercetin, a flavonoid present in vegetables and fruits. Quercetin was tested against gram-positive and gram-negative bacteria and was found to exert selective antibacterial activity against Staphylococcus aureus, including methicillin-resistant S. aureus (MRSA), and Staphylococcus epidermidis. Some clinical MRSA strains showed remarkable susceptibility to quercetin. In combination with antibiotics, such as oxacillin, ampicillin, vancomycin, gentamicin, and erythromycin, quercetin sho...

2010-01-01

210

The effects of chemicals in the presence of cellophane on X-ray-induced point mutation and gene conversion in Aspergillus midulans

The DFNA5 gene, responsible for hearing loss and involved in cancer, encodes a novel apoptosis-inducing protein

The presence of washed or unwashed cellophane alone or together with a bleomycin, mitomycin C or hydrochlorothiazide, ('Esidrex') showed no appreciable effect on survival of either unirradiated or irradiated conidia. Irradiation for a period of 20min reduced the survival of conidia to 20%. The growth of irradiated conidia in the presence of bleomycin, mitomycin C or Esidrex is associated with a 2- to 3-fold increase in the frequency of gene convertants, but was not accompanied by an increase in point mutants. When conidia were grown on cellophane but otherwise treated as before the frequency of gene convertants was increased 8-fold, but induction of point mutants was negligible. This effect was the same for irradiated and unirradiated conidia. The environment created by the cellophane in contract with the medium appears to affect the action of each of the three compounds synergistically. (author).

211

British Library Electronic Table of Contents (United Kingdom)

DFNA5 was first identified as a gene causing autosomal dominant hearing loss (HL). Different mutations have been found, all exerting a highly specific gain-of-function effect, in which skipping of exon 8 causes the HL. Later reports revealed the involvement of the gene in different types of cancer. Epigenetic silencing of DFNA5 in a large percentage of gastric, colorectal and breast tumors and p53-dependent transcriptional activity have been reported, concluding that DFNA5 acts as a tumor suppressor gene in different frequent types of cancer. Despite these data, the molecular function of DFNA5 has not been investigated properly. Previous transfection studies with mutant DFNA5 in yeast and in mammalian cells showed a toxic effect of the mutant protein, which was not seen after transfection ...

2011-01-01

212

Somatic mutations detected by immunofluorescence and flow cytometry

Mutations at the cysteine codons of the recA gene of Escherichia coli

We have at hand the tools for development of both a single amino acid substitution and a gene loss type assay for somatic cell mutations in human red cells. We are close to being able to assess the assays as possible means for screening the human population for individuals who may be a risk of acquiring abnormally high frequencies of mutant cells. The cause for such a high frequency of mutant cells could be a prior exposure of the individual to large amount of mutagen, or it could indicate a member of a vulnerable subpopulation that may have poor DNA repair systems. Either of these cases could well be an indication that the particular individual is at high risk that exposure to mutagens could lead to potential pathology. In the near future we expect to determine the reliability of the assays and to perform experiments to confirm the validity of flow cytometry in measuring real somatic mutagenic events that occur in vivo. (orig./AJ).

213

Effects of chemicals in the presence of cellophane on X-ray-induced point mutation and gene conversion in Aspergillus midulans

Each of the three cysteine residues in the Escherichia coli RecA protein was replaced with a number of other amino acids. To do this, each cysteine codon was first converted to a chain-terminating amber codon by oligonucleotide-directed mutagenesis. These amber mutants were then either assayed for function in different suppressor strains or reverted by a second round of mutagenesis with oligonucleotides that had random sequences at the amber codon. Thirty-three different amino acid substitutions were obtained. Mutants were tested for three functions of RecA: survival following UV irradiation, homologous recombination, and induction of the SOS response. It was found that although none of the cysteines is essential for activity, mutations at each of these positions can affect one or more of the activities of RecA, depending on the particular amino acid substitution. In addition, the cysteine at position 116 appears to be involved in the ...

214

Science at the Theater: Hot Technology, Cool Science

The presence of washed or unwashed cellophane alone or together with a bleomycin, mitomycin C or hydrochlorothiazide, ('Esidrex') showed no appreciable effect on survival of either unirradiated or irradiated conidia. Irradiation for a period of 20min reduced the survival of conidia to 20%. The growth of irradiated conidia in the presence of bleomycin, mitomycin C or Esidrex is associated with a 2- to 3-fold increase in the frequency of gene convertants, but was not accompanied by an increase in point mutants. When conidia were grown on cellophane but otherwise treated as before the frequency of gene convertants was increased 8-fold, but induction of point mutants was negligible. This effect was the same for irradiated and unirradiated conidia. The environment created by the cellophane in contract with the medium appears to affect the action of each of the three compounds synergistically.

1984-08-01

215

ScienceCinema

...and welcome to ...lab also known as berkeley lab my name is jeff miller and ...and a public affairs i'd like to ? ...but space is science center and ...berkeley albany high school science department and berkeley high school science department and oakland high school science ...be a q. and ...here please use and because we wanna make sure that your questions are here ...heard of also for the latest developments on science and technology ...guy we're going to be any more and more new features i hope ...and change ...thank you ? much and thank you for coming on the welcome to my world of and mayotte science journalist and what i've done for the last almost thirty years ...people about things about which there passionate and national religion tonight and ...people to explain the science and and i asking the question so what ...and ...worldwide and what it does best ? uh ...bench science and turn it into reality what do you scientists and ...uh they take scientific theory and they turn ...

216

[Intraspecies antagonism of Sh. flexneri in an HEp-2 cell line model].

Yeast allosteric chorismate mutase is locked in the activated state by a single amino acid substitution

The authors describe an effect of suppression of invasion of the guinea pig eye conjunctiva and the HEp-2 epithelial cells by virulent Sh. flexneri bacilli, with a simultaneous administration of the same dose of avirulent shigella mutants, genetically connected with them. The data of morphological study and experiments with 3H-glucose labeled shigellae carried out on the cell species model indicated that the bacterial competition for the specific sites for absorption on the epithelial cells underlay the observed phenomenon. PMID:331774

1977-06-01

217

Viral suppression of multiple escape mutants by de novo CD8⁺T cell responses in a human immunodeficiency virus-1 Infected elite suppressor

Chorismate mutase, a branch-point enzyme in the aromatic amino acid pathway of Saccharomyces cerevisiae, and also a mutant chorismate mutase with a single amino acid substitution in the C-terminal part of the protein have been purified approximately 20-fold and 64-fold from overproducing strains, respectively. The wild-type enzyme is activated by tryptophan and subject to feedback inhibition by tyrosine, whereas the mutant enzyme does not respond to activation by tryptophan nor inhibition by tyrosine. Both enzymes are dimers consisting of two identical subunits of M_r 30,000, each one capable of binding one substrate and one activator molecule. Each subunit of the wild-type enzyme also binds one inhibitor molecule, whereas the mutant enzyme lost this ability. The enzyme reaction was observed by "1H NMR and shows a direct and irreversible conversion of chorismate to prephenate without the accumulation of any enzyme-free ...

218

Unraveling photosystems. Final technical report

Elite suppressors or controllers (ES) are HIV-1 infected patients who maintain undetectable viral loads without treatment. While HLA-B*57-positive ES are usually infected with virus that is unmutated...Full Text Available

219

Quantitative transfer of the molybdenum cofactor from xanthine oxidase and from sulphite oxidase to the deficient enzyme of the nit-1 mutant of Neurospora crassa to yield active nitrate reductase.

This report highlights four main points. (1) A residue substitution in phosphoribulokinase of Synechocystis PCC 6803 renders the mutant light-sensitive. The authors isolated a light-sensitive mutant (BRLS) of the photosynthetic cyanobacterium Synechocystis 6803 that does not survive exposure to bright light; 70% of BRLS cells die upon exposure to light of > 3000 lux for 2 hr. (2) Excitation energy transfer from phycocyanin to chlorophyll in an apcA-defective mutant of Synechocystis sp. PCC 6803. A greenish mutant of the normally bule-green cyanobacterium Synechocystis sp. PC 6803, designated UV6p, was isolated and characterized. UV6p possesses functional photosystems I and II but lacks normal light harvesting phycobilisomes because allophycocyanin is absent and core-specific linker proteins are almost entirely absent. (3) Deletion of the psbG1 gene of the cyanobacterium Synechocystis sp. PCC 6803 ...

1997-09-01

220

Phosphorylation of ?6-Tubulin by Protein Kinase C? Activates Motility of Human Breast Cells*

An assay method is described for measurement of absolute concentrations of the molybdenum cofactor, based on complementation of the defective nitrate reductase ('apo nitrate reductase') in extracts...Full Text Available

1984-04-15

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25

221

Mutational Analysis of the Carboxy-Terminal (YGX)₄ Repeat Domain of CpsD, an Autophosphorylating Tyrosine Kinase Required for Capsule Biosynthesis in Streptococcus pneumoniae

Engineered overexpression of protein kinase Cα (PKCα) was previously shown to endow nonmotile MCF-10A human breast cells with aggressive motility. A traceable mutant of PKCα...Full Text Available

2009-06-26

222

Molecular characterization of cap3A, a gene from the operon required for the synthesis of the capsule of Streptococcus pneumoniae type 3: sequencing of mutations responsible for the unencapsulated phenotype and localization of the capsular cluster on the pneumococcal chromosome.

In Streptococcus pneumoniae, CpsB, CpsC, and CpsD are essential for encapsulation, and mutants containing deletions of cpsB, cpsC, or cpsD...Full Text Available

2003-05-01

223

Induced mutation in narrow-leafed lupin improvement: An example of herbicide tolerance

The complete nucleotide sequence of the cap3A gene of Streptococcus pneumoniae, which is directly responsible for the transformation of some unencapsulated, serotype 3 mutants to the encapsulated phenotype,...Full Text Available

1994-10-01

224

Induced mutation in Lupinus mutabilis sweet in Peru

Spontaneous mutation has been discovered and utilized in domestication of narrow-leafed lupin (Lupinus angustifolius L.). As the result of the domestication, lupin has become a dominant grain legume crop in Western Australia. Facing the new challenge of developing herbicide tolerance cultivars, chemical mutagenesis has been used to create new tolerance to herbicide. This paper reports the characterization of two lupin mutants (Tanjil-AZ-33 and Tanjil-AZ-55) that are highly tolerant to metribuzin herbicide. A dose response study over 8 doses revealed that Tanjil-AZ-33 was 6 times more tolerant to metribuzin than the original parental cultivar Tanjil by measure of LD50. This mutant Tanjil-AZ-33 is the most tolerant germplasm in narrow-leafed lupin. Both mutants also maintain the high resistance to the disease anthracnose as cv Tanjil. Seed yield based on small field plots (3.6 m"2) under irrigation was 4.2 t/ha for ...

2008-08-12

225

Individual products of the adenovirus 12S and 13S EIa mRNAs stimulate viral EIIa and EIII expression at the transcriptional level.

Mutagenesis of Lupinus mutabilis was started at the UNA LM (Peru) to obtain mutants with low alkaloid content and early germination. Varieties SCG 25 and Lib 020 were irradiated with gamma radiation. The optimum dose for the SCG 25 variety was 15 Krad and for Lib 020 15 to 20 Krad. The relation between the plant height and radiation dose fits the quadratic polynomial model.

1984-04-01

226

High yielding mutants in sesamum

Recombinant plasmids containing mutant or wild-type adenovirus serotype 2 EIa genes that produce the 12S mRNA alone, the 13S mRNA alone, or both mRNAs were cotransfected into HeLa cells with plasmids...Full Text Available

1984-07-01

227

Expression of V642 APP mutant causes cellular apoptosis as Alzheimer trait-linked phenotype.

Mutation breeding in one of the cultigens TMV-5 in Sesamum is undertaken with 5 kr, 10 kr, 15 kr, 20 kr, 60 kr and 80 kr, dosages of gamma-rays. 60 kr and 80 kr dosages were found to be lethal from the complete failure of seed germination. The mutagen had a heterotic effect on the different characters and the promising variants obtained in this programme are proposed to be maintained by pureline breeding for their possible release as new varieties. (author).

228

Evaluation of radiation induced sesame mutants as affected by some micro nutrients

APP is a transmembrane precursor of beta-amyloid. In dominantly inherited familial Alzheimer's disease (FAD), point mutations V6421, V642F and V642G have been discovered in APP695. Here we show that...Full Text Available

1996-02-01

229

Distribution and threshold expression of the tRNA(Lys) mutation in skeletal muscle of patients with myoclonic epilepsy and ragged-red fibers (MERRF).

Tow experiments were carried out in 1981 and 1982 growth seasons at the greenhouse of the department of agriculture for soils and water researches, atomic energy authority, at inshas, to investigate the responses of two mutation derived lines of sesame and the local cultivar giza 25 to the application of micro nutrients. The possible effect of radiation on germination and growth of sesame seed was also studied in a separate experiment conducted in 1985 season, at inshas.

230

Crystallization and preliminary X-ray diffraction studies of two thermostable ?-galactosidases from glycoside hydrolase family 36

We investigated the distribution and expression of mutant mtDNAs carrying the A-to-G mutation at position 8344 in the tRNA(Lys) gene in the skeletal muscle of four patients with myoclonus epilepsy and...Full Text Available

1992-12-01

231

Complementation of areA- regulatory gene mutations of Aspergillus nidulans by the heterologous regulatory gene nit-2 of Neurospora crassa.

α-Galactosidases from thermophilic organisms have gained interest owing to their applications in the sugar industry. The α-galactosidases AgaA, AgaB and AgaA A355E mutant from Geobacillus...Full Text Available

232

Alteration of nucleoside diphosphate binding specificity of E. coli elongation factor Tu (EF-Tu) by single amino acid substitution at position 138

Loss-of-function mutations in the regulatory gene areA of Aspergillus nidulans prevent the utilization of a wide variety of nitrogen sources. The phenotypes of nit-2 mutants of Neurospora crassa suggest...Full Text Available

1987-06-01

233

A deficiency in cyclic AMP results in pH-sensitive growth of Escherichia coli K-12.

A single amino acid substitution (Asp #-># Asn) at position 138 of E. coli EF-Tu was induced in the tufA gene by an M13 phage oligonucleotide site-directed mutagenesis protocol. The mutated tufA gene was then subcloned in a plasmid vector and expressed in maxicells. The properties of ["3"5S]methionine labelled mutant and wild type EF-Tu's were compared by in vitro assays. Mutant and wild-type EF-Tu's bound EF-Ts with approximately equal affinities. The 138-Asn mutation greatly reduced the protein's affinity for GDP; however, this mutation dramatically increased the proteins affinity for XDP. The mutant protein forms a stable complex with phe-tRNA and XTP, which binds to ribosomes; whereas, it does not form a complex with phe-tRNA and GTP. These results suggest that in EF-Tu x NDP complexes amino acid residue 138 must interact with the substituent on C-2 of the purine ring. Thus in wild-type EF-Tu Asp-138 would H-bond to ...

1987-06-07

234

U.V. repair in deep-sea bacteria

Mutants of Escherichia coli K-12 deficient in adenyl cyclase (cya) and catabolite activator protein (crp) have been shown to grow more slowly than their parent strains in glucose-minimal medium. Their...Full Text Available

1988-08-01

235

Interaction of aerobic soil bacteria with plutonium(VI)

Exposure of cells to light of less than 320 nanometers wavelengths may lead to lethal lesions and perhaps carcinogenesis. Many organisms have evolved mechanisms to repair U.V. light-induced damage. Organisms such as deep-sea bacteria are presumably never exposed to U.V. light and perhaps occasionally to visible from bioluminescence. Thus, the repair of U.V. damage in deep-sea bacterial DNA might be inefficient and repair by photoreactivation unlikely. The bacteria utilized in this investigation are temperature sensitive and barophilic. Four deep-sea isolates were chosen for this study: PE-36 from 3584 m, CNPT-3 from 5782 m, HS-34 from 5682 m, and MT-41 from 10,476 m, all are from the North Pacific ocean. The deep-sea extends from 1100 m to depths greater than 7000 m. It is a region of relatively uniform conditions. The temperature ranges from 5 to -1"0C. There is no solar light in the deep-sea. Deep-sea bacteria are ...

1986-06-08

236

Improved oil recovery using bacteria isolated from North Sea petroleum reservoirs

We studied the interaction of Pu(VI) with Pseudomonas stutzeri ATCC 17588 and Bacillus sphaericus ATCC 14577, representatives of the main aerobic groups of soil bacteria present in the upper soil layers. The accumulation studies have shown that these soil bacteria accumulate high amounts of Pu(VI). The sorption efficiency toward Pu(VI) decreased with increasing biomass concentration due to increased agglomeration of the bacteria resulting in a decreased total surface area and number of available complexing groups. Spores of Bacillus sphaericus showed a higher biosorption than the vegetative cells at low biomass concentration which decreased significantly with increasing biomass concentration. At higher biomass concentrations (> 0.7 g/L), the vegetative cells of both strains and the spores of B. sphaericus showed comparable sorption efficiencies. Investigations on the pH dependency of the biosorption and extraction ...

2000-08-22

237

Appendix W: deep sea biophysics (microbiology and amphiped studies)

During secondary oil recovery, water is injected into the formation to sweep out the residual oil. The injected water, however, follows the path of least resistance through the high-permeability zones, leaving oil in the low-permeability zones. Selective plugging of these their zones would divert the waterflood to the residual oil and thus increase the life of the well. Bacteria have been suggested as an alternative plugging agent to the current method of polymer injection. Starved bacteria can penetrate deeply into rock formations where they attach to the rock surfaces, and given the right nutrients can grow and produce exo-polymer, reducing the permeability of these zones. The application of microbial enhanced oil recovery has only been applied to shallow, cool, onshore fields to date. This study has focused on the ability of bacteria to enhance oil recovery offshore in the North Sea, where the environment can be ...

1995-12-31

238

A study of bacterial isolates from corneal specimens and their antibiotic resistance profile

CNPT-3 is the laboratory designation of a strain of bacteria that reproduces best at deep-sea pressures. It was isolated from a sample collected at a 5800 m depth of the Pacific Ocean. This isolation was achieved from a sample that had been retrieved without warning. This year we demonstrated that there are similarly behaving bacteria that can be isolated from samples even when retrieved with decompression. The purpose of this project was to define the temperatures and pressures over which CNPT-3 can exist and function. (1) At 2"0C CNPT-3 is eurybathic from about 1000 to 6500 m, as judged from an only slightly pressure dependent generation time. (2) CNPT-3 is unquestionably barophilic at 2"0C, with doubling times of 9 hours at 580 bars and over 18 hours at 1 bar. (3) At 10"0C, reproduction is adversely affected at 1 bar to the extent that CNPT-3 becomes obligately barophilic at 10"0C. Yet reproduction is enhanced above 280 bars and occurs with ...

1981-04-01

239

Thermophilic slurry-phase treatment of petroleum hydrocarbon waste sludges

We aim to examine the spectrum of bacteria causing corneal infections and their antibiotic susceptibility patterns. This will serve as a guideline for empiric therapy of corneal infections. We conducted the study over a period of 18 months from March 2001 through December 2002 in King Abdul-Aziz University Hospital, Riyadh, Kingdom of Saudi Arabia. Corneal specimens taken from 200 patients were inoculated directly onto different types of media. The isolates were identified and then tested against the appropriate topical or systemic antibiotics. Sixty-seven (33.5%) of the total specimens were culture positive and 133 (66.5%) were culture negative. Fourteen (7%) of these showed organisms in the Gram stained smears and correlated well with the culture reports. Of the 67 positive cultures, 53 (79.1%) were Gram-positive bacteria mostly coagulase-negative Staphylococci 29 (43.3%) followed by Streptococcus pneumoniae (S. pneumoniae) 13 (19.4%). Among ...

240

Thermophilic slurry-phase treatment of petroleum hydrocarbon waste sludges

Chemoheterotrophic thermophilic bacteria were used to achieve enhanced hydrocarbon degradation during slurry-phase treatment of oily waste sludges from petroleum refinery operations. Aerobic and anaerobic bacterial cultures were examined under thermophilic conditions to assess the effects of mode of metabolism on the potential for petroleum hydrocarbon degradation. The study determined that both aerobic and anaerobic thermophilic bacteria are capable of growth on petroleum hydrocarbons. Thermophilic methanogenesis is feasible during the degradation of hydrocarbons when a strict anaerobic condition is achieved in a slurry bioreactor. Aerobic thermophilic bacteria achieved the largest apparent reduction in chemical oxygen demand, freon extractable oil, total and volatile solid,s and polycyclic aromatic hydrocarbons (PAHs) when treating oily waste sludges. The observed shift with time in the molecular weight distribution of ...

1995-12-31

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241

Phenotypic characterization of human pathogenic bacteria in fish from the coastal waters of South West Cameroon: public health implications.

Chemoheterotrophic thermophilic bacteria were used to achieve enhanced hydrocarbon degradation during slurry-phase treatment of oily waste sludges from petroleum refinery operations. Aerobic and anaerobic bacterial cultures were examined under thermophilic conditions to assess the effects of mode of metabolism on the potential for petroleum hydrocarbon degradation. The study determined that both aerobic and anaerobic thermophilic bacteria are capable of growth on petroleum hydrocarbons. Thermophilic methanogenesis is feasible during the degradation of hydrocarbons when a strict anaerobic condition is achieved in a slurry bioreactor. Aerobic thermophilic bacteria achieved the largest apparent reduction in chemical oxygen demand, freon extractable oil, total and volatile solid,s and polycyclic aromatic hydrocarbons (PAHs) when treating oily waste sludges. The observed shift with time in the molecular weight distribution of ...

1995-04-24

242

Mine drainage treatment; Kogyo haisui shori

Increasing economic and recreational opportunities, attractive scenery and a perception of a better quality of life are luring people to the coast. Unfortunately, these activities together with the commensurate increase in population in the area inevitably result in pollution of coastal waters with excessive microorganisms and other pollutants. Microbial pollutants not only contaminate the coastal water but also aquatic food sources, thus posing a health risk to consumers. Fish is a major source of protein in Cameroon, especially in the coastal areas. In this study, we investigated the microbiological quality of fish from the Limbe and Tiko beaches in South West Cameroon from May to October 2007. We isolated human pathogenic bacteria from three anatomic sites (skin, gills, intestine) of 50 fish (150 specimens) and investigated their susceptibility patterns to a battery of antibiotics. Data were analyzed statistically using chi2 with significance set at p South West ...

243

Identification of culturable and originally non-culturable endophytic bacteria isolated from shoot tip cultures of banana cv. Grand Naine

The generation of acidic mine drainage is based on the oxidation dissolution of sulfide minerals due to the contact of ores with the natural water and the air. Namely, the sulfuric acid promotes the dissolution of sulfide minerals and gangue minerals, and Fe{sup 2+} is further oxidized to turn into Fe{sup 3+}, which acts as an oxidizer for other sulfide minerals and promotes the dissolution of the same. This paper roughly describes a mine drainage treatment focusing on an Fe{sup 2+} neutralization method and an iron bacteria oxidation method. The iron bacteria oxidation method is a method of oxidizing Fe{sup 2+} into Fe{sup 3+} by using iron bacteria, and then removing Fe{sup 3+} with calcium carbonate. This method has been used for treating the drainage in the Sakuhara Mine and the former Matsuo Mine, with good results. The paper finally introduces, as power-saving low-cost mine drainage treatment methods, a method of ...

1996-05-25

244

British Library Electronic Table of Contents (United Kingdom)

In this article we describe the identification of endophytic bacteria belonging to three groups isolated from shoot tip cultures of banana cv. Grand Naine in a recent study (Thomas et?al. 2008) based on partial 16S rRNA gene sequence homology analysis. The first group included banana stocks that displayed obvious colony growth on MS based tissue culture medium during the first in?vitro passage. The second group constituted stocks that were tissue index-negative for cultivable bacteria initially but turned index-positive after a few to several (4?8) in?vitro passages while the third group formed one sub-stock that turned index-positive after about 18 passages. The organisms belonged to about 20 different genera comprising of ?, ?, ?-proteobacteria, Gram-positive firmicutes and actinobacteri...

2008-01-01

245

Growth and reproduction of nematodes isolated from tap water; Suidosui kara bunrisareta senchurui no zoshoku tokusei

Effects of microwaves on cell survival at elevated temperatures

This paper elucidates morphological characteristics, reproduction forms and ecological characteristics of Plectus sp. and Rhabditis sp. which are most frequently detected nematodes separated from tap water. The paper also discussed experimentally establishment of cultivating conditions for these nematodes, and behavior and reproduction characteristics of nematodes under widely ranging conditions of temperatures, bacteria concentrations and pH. Plectus sp. grows in hermaphroditic individuals, while Rhabditis sp. grows only in female. An LE culture medium can cultivate nematodes that appear in tap water, and is suitable for subculture of nematodes. Conditions of temperatures from 20{degree}C to 25{degree}C, pH and inoculated concentration of bacteria at 10{sup 8} cell {center_dot} ml{sup -1} are suitable for reproduction of Plectus sp. and Rhabditis sp. Plectus sp. and Rhabditis sp. prefer mild temperatures for reproduction, cannot reproduce ...

1996-08-10

246

Biocatalytic desulfurization of petroleum and middle distillates

Since microwaves are used in human cancer therapy, information on specific biological effects of microwaves at elevated temperatures is important. To help supply this information, we exposed mammalian cells (CHO) and bacteria (Serratia marcescens) to hyperthermal temperatures (43, 44, and 45/sup o/C for CHO and 48, 49, and 50/sup o/C for the bacteria) with and without microwave irradiation. Temperature control was maintained by a refrigeration-reheat system and high-velocity water recirculation. The 2450-MHz microwave source was operated in a pulsed mode with power density up to 500 mW/cm/sup 2/. As expected, the survival curve slopes for both cell types increased rapidly with temperature, doubling for each degree Celsius. Microwave irradiation produced no significant change in extrapolation number for either cell type. However, survival curves of CHO cells which received microwaves were steeper by a factor of 1.25 than their sham-irradiated ...

1981-12-01

247

Synergistic interaction of eugenol with antibiotics against Gram negative bacteria

Biocatalytic Desulfurization (BDS) represents an alternative approach to the reduction of sulfur in fossil fuels. The objective is to use bacteria to selectively remove sulfur from petroleum and middle distillate fractions, without the concomitant release of carbon. Recently, bacteria have been developed which have the ability to desulfurize dibenzothiophene (DBT) and other organosulfur molecules. These bacteria are being developed for use in a biocatalyst-based desulfurization process. Analysis of preliminary conceptual engineering designs has shown that this process has the potential to complement conventional technology as a method to temper the sulfur levels in crude oil, or remove the recalcitrant sulfur in middle distillates to achieve the deep desulfurization mandated by State and Federal regulations. This paper describes the results of initial feasibility studies, sensitivity analyses and conceptual design work. ...

1993-02-01

248

British Library Electronic Table of Contents (United Kingdom)

Eugenol, the principal chemical component of clove oil from Eugenia aromatica has been long known for its analgesic, local anesthetic, anti-inflammatory, and antibacterial effects. The interaction of the eugenol with ten different hydrophobic and hydrophilic antibiotics was studied against five different Gram negative bacteria. The MIC of the combination was found to decrease by a factor of 5-1000 with respect to their individual MIC. This synergy is because of the membrane damaging nature of eugenol, where 1mM of its concentration is able to damage nearly 50% of the bacterial membrane. Eugenol was also able to enhance the activities of lysozyme, Triton X-100 and SDS in damaging the bacterial cell membrane. The hydrophilic antibiotics such as vancomycin and b-lactam antibiotics which have ...

2009-01-01

249

Responses of Bark Beetle-Associated Bacteria to Host Monoterpenes and Their Relationship to Insect Life Histories

British Library Electronic Table of Contents (United Kingdom)

Bark beetles that colonize living conifers and their microbial associates encounter constitutive and induced chemical defenses of their host. Monoterpene hydrocarbons comprise a major component of these allelochemicals, and many are antibiotic to insects, fungi, and bacteria. Some bark beetle species exhaust these defenses by killing their host through mass attacks mediated by aggregation pheromones. Others lack adult aggregation pheromones and do not engage in pheromone-mediated mass attacks, but rather have the ability to complete development within live hosts. In the former species, the larvae develop in tissue largely depleted of host terpenes, whereas in the latter exposure to these compounds persists throughout development. A substantial literature exists on how monoterpenes affect b...

2011-01-01

250

Pit lakes: their characteristics and the potential for their remediation

In vitro competitive adhesion and production of antagonistic compounds by lactic acid bacteria against fish pathogens

Pit lakes form when open-pit mining operations are discontinued and dewatering ceases. The increase in open-pit metal mining since the 1970s will lead to the formation of numerous pit lakes over the next 50 years. Many of these lakes will develop acid sulfate conditions with high levels of dissolved metals. Approaches to remediation of these conditions that have been recommended include the addition of lime or other alkaline materials and the stimulation of sulfate-reducing bacteria. However, prevention rather than remediation is probably the preferable approach. Measures to prevent oxidation of mining waste and wall rocks, including measures to fill pits quickly with water, to inhibit the activity of acidophilic sulfur-oxidizing bacteria, and to promote anoxic conditions at the lake bottoms may minimize the formation of acids and dissolved metals. (orig.)

2000-10-01

251

British Library Electronic Table of Contents (United Kingdom)

The present study describes the screening of five lactic acid bacteria (LAB) for use as probiotics based on their competitive adhesion and production of antagonistic substances against some fish pathogens. A reduction of adhesion of all pathogenic strains tested was obtained with three of the LAB strains (Lactococcus lactis subsp. lactis CLFP100, Lactococcus lactis subsp. cremoris CLFP102 and Lactobacillus curvatus CLFP150). With the exception of fish pathogens Flavobacterium psychrophilum and Renibacterium salmoninarum that were not inhibited by LAB strains, production of antagonistic compounds by all tested LAB was observed against at least one of the indicator strains. Based on mucus adhesion, competitive exclusion, and suppression of fish pathogen growth, the selected LAB strains can b...

2007-01-01

252

Immobilization of bacteria in microgel grafted onto macroporous polyethylene

How microcystin-degrading bacteria express microcystin degradation activity

The development of 'Green Chemistry' requires new materials to replace the conventional organic chemistry by biological catalysts, to produce fine chemicals in an environmentally friendly manner. Microbial whole cells can be directly used as biocatalysts, providing a simple and cheap methodology since enzyme isolation and purification are avoided. High-density polyethylene (HDPE) is a very stable polymer though it can be activated by gamma radiation to induce grafting. Glycidyl methacrylate was grafted onto macroporous HDPE and PP in the range of 1-6%, proportional to the initial monomer concentration. Grafted polymers were further chemically modified with ethylenediamine to generate a cationic hydrogel of micron-size thickness onto the internal polymer surfaces. Modified polymers were able to immobilize Gram-positive and Gram-negative bacteria that can catalyze a chemical reaction as efficient as free cells do.

2010-03-15

253

British Library Electronic Table of Contents (United Kingdom)

Abstract Alkali tolerance and the mechanism of microcystin (MC) degradation were investigated in the MC-degrading bacterial species, Sphingopyxis sp. C-1, to better understand the increased MC degradation under the alkaline conditions that arise during the disappearance of water blooms. MC-degrading bacteria harbour mlrA, mlrB and mlrC that encode MC-degrading enzymes. Sphingopyxis sp. C-1 also possesses these genes, as well as the mlrD gene that has been assumed to encode MC and its degradation transporter. This study demonstrated that MC degradation activity was promoted by the intermittent addition of microcystin-LR (MCLR) to cultures of strain C-1. That the expression of mlrA, mlrB and mlrC is induced by MCLR also was indicated, whereas that of mlrA and mlrB is induced by the MCLR degr...

2011-01-01

254

Food-grade gene expression in lactic acid bacteria

British Library Electronic Table of Contents (United Kingdom)

Abstract In the 1990s, significant efforts were invested in the research and development of food-grade expression systems in lactic acid bacteria (LAB). At this time, Lactococcus lactis in particular was demonstrated to be an ideal cell factory for the food-grade production of recombinant proteins. Steady progress has since been made in research on LAB, including Lactococcus, Lactobacillus and Streptococcus, in the areas of recombinant enzyme production, industrial food fermentation, and gene and metabolic pathway regulation. Over the past decade, this work has also led to new approaches on chromosomal integration vectors and host/vector systems. These newly constructed food-grade gene expression systems were designed with specific attention to self-cloning strategies, food-grade selection...

2011-01-01

255

Electrochemistry of a semiconductor chalcopyrite concentrate leaching by Thiobacillus ferrooxidans

Efficacy of three commercially available ballast water biocides against vegetative microalgae, dinoflagellate cysts and bacteria

Using carbon-paste-CuFeS{sub 2} electrodes and a cyclic voltammetric technique, it was found that a large number of intermediate electrochemical oxidation reactions were associated with the dissolution of chalcopyrite in presence and absence of bacteria. The effects of concentrations of copper, ferrous and ferric ions, as well as of agitation on the peaks of cyclic voltammograms were measured. It was established that chalcopyrite oxidation was solid-state controlled as suggested by the data of chronopotentiometric and chronoamperometric measurements. The activation energy of solid state diffusion of chalcopyrite leaching was determined by the Sand's method to be {triangle}E{sub a} = 20.5 kJ. The leaching mechanism is discussed in terms of solid-state properties (energy bonding) of the n-type semiconductor chalcopyrite and energy density states of redox systems of acidic bacterial leach media. A generalized model for the mechanism of chalcopyrite leaching ...

1991-01-01

256

British Library Electronic Table of Contents (United Kingdom)

One proposed solution to the problem of ballast-mediated aquatic invasions involves chemically treating ballast water to kill key target organisms. Here, we examine the efficacy of three commercially available ballast water biocides using vegetative microalgae, dinoflagellate resting cysts and bacteria as test organisms. Chemicals tested were the ballast water biocides SeaKleen and Peraclean Ocean, and the chlorine dioxide biocide Vibrex. Results demonstrate that the applicability of each of the three chemical biocides as a routine ballast water treatment is limited by factors such as cost, biological effectiveness and possible residual toxicity of the discharged ballast water (assessed on the basis of impact on motility of vegetative marine microalgae). Of the three biocides tested, Perac...

2007-01-01

257

Comparative activity of tigecycline and tetracycline on Gram-negative and Gram-positive bacteria revealed by a multicentre study in four North European countries

British Library Electronic Table of Contents (United Kingdom)

Abstract Background: This study involves a multicentre surveillance of tigecycline and tetracycline activity against Gram-negative and Gram-positive bacteria from primary care centres (PCCs), general hospital wards (GHWs) and intensive care units (ICUs) in Denmark (n == 9), Finland (n == 10), Norway (n == 7) and Sweden (n == 19). Methods: The hospitals were each asked to test 30 consecutive Gram-positive and 30 Gram-negative clinical isolates. Supportive information accompanying each isolate included the study centre, ward level (PCC, GHW, or ICU), patient identification and source of the isolate. Minimum inhibitory concentrations (MICs) for tetracycline and tigecycline were determined with the Etest. Results: The isolates collected comprised 1610 Gram-negative and 1767 Gram-positive clini...

2011-01-01

258

Antimicrobial silver-montmorillonite nanoparticles to prolong the shelf life of fresh fruit salad

British Library Electronic Table of Contents (United Kingdom)

In this work, silver-montmorillonite (Ag-MMT) antimicrobial nanoparticles have been obtained by allowing silver ions from nitrate solutions to replace the Na^+ of natural montmorillonite and then to be reduced by a thermal treatment. Ag-MMT were used as active antimicrobial compounds to improve the shelf life of fresh fruit salad. In order to assess their influence on product shelf life, sensorial and microbiological quality has been monitored during the storage. The microbiological quality was determined by monitoring the principal spoilage microorganisms (mesophilic and psychrotrophic bacteria, coliforms, lactic acid bacteria, yeasts and molds). Additionally, the evolution of sensorial quality was assessed by monitoring color, odor, firmness and product overall quality. The Ag-MMT nanopa...

2011-01-01

259

A lytic enzyme cocktail from Streptomyces sp. B578 for the control of lactic and acetic acid bacteria in wine

British Library Electronic Table of Contents (United Kingdom)

Beside yeasts, lactic acid bacteria (LAB) are the most abundant microbes in must during vinification. Whereas Oenococcos oeni is commercially used as a starter culture for the biological acid reduction in wines, other species are responsible for different types of wine spoilage. Members of the genera Pediococcus, Weissella, Leuconostoc, and Lactobacillus are producers of exopolysaccharide slimes, biogenic amines, acetic acid, and other off-flavors. In order to control microbial growth, different procedures such as heating of must and addition of sulfite or lysozyme from egg white are generally applied. Yet, because of health risks, the application of sulfite should be reduced and lysozyme is not effective against all LAB. In this study, we describe exoenzymes from a Streptomyces sp. strain...

2009-01-01

260

Regulation of human ribosomal RNA transcription.

Long-term Retinal Function and Structure Rescue Using Capsid Mutant AAV8 Vector in the rd10 Mouse, a Model of Recessive Retinitis Pigmentosa

We have used a cell-free polymerase I transcription system derived from HeLa cells to study the regulation of human rRNA synthesis. Analysis of deletion mutants spanning the start site of transcription at nucleotide +1 indicates that the control region affecting initiation of human rRNA synthesis is contained within sequences from nucleotides -158 to +18. This promoter region can be subdivided into (i) a central segment of approximately 40 base pair that is required for transcription and (ii) flanking sequences that influence the efficiency of transcription in vitro. We have examined the in vitro transcriptional activity of the human extract under various conditions that are thought to modulate rRNA synthesis in vivo. Cell-free extracts prepared from HeLa cells infected with adenovirus 2 synthesize human rRNA at levels greatly decreased relative to uninfected cell extracts. By contrast, in vitro transcription of human rRNA is stimulated 2- to 3-fold by the addition ...

1983-06-01

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261

British Library Electronic Table of Contents (United Kingdom)

The retinal degeneration 10 (rd10) mouse is a well-characterized model of autosomal recessive retinitis pigmentosa (RP), which carries a spontaneous mutation in the ? subunit of rod cGMP-phosphodiesterase (PDE?). Rd10 mouse exhibits photoreceptor dysfunction and rapid rod photoreceptor degeneration followed by cone degeneration and remodeling of the inner retina. Here, we evaluate whether gene replacement using the fast-acting tyrosine-capsid mutant AAV8 (Y733F) can provide long-term therapy in this model. AAV8 (Y733F)-smCBA-PDE? was subretinally delivered to postnatal day 14 (P14) rd10 mice in one eye only. Six months after injection, spectral domain optical coherence tomography (SD-OCT), electroretinogram (ERG), optomotor behavior tests, and immunohistochemistry showed tha...

2011-01-01

262

Localized mutagenesis of the tetracycline promoter region in pBR322 by 4,5',8-trimethylpsoralen

Induction of mutation in Trichoderma viride for conversion of natural cellulose into glucose

In vitro mutagenesis of functional DNA gene fragments by covalently reactive agents permits one in principle to examine the consequent alterations in DNA sequence directly. I have carried out selective mutagenesis of the tetracycline resistance gene in the plasmid pBR322 using the long wavelength UV light activated reaction of 4,5',8-trimethylpsoralen (TMP). The mutagenized DNA sequence was the EcoR1-Hind III restriction fragment in the vicinity of the Tcsup(R) promoter. Two classes of mutants were obtained. One exhibited a high level of Tc resistance (40-60 ..mu..g/ml) but still lower than the wild-type. Interestingly, these showed no sequence alterations at all in the vicinity of the TMP-reacted fragment. The other class of mutants exhibited low levels of drug resistance (< 20 ..mu..g/ml) and two of those that were sequenced were found to contain a 15-base pair insertion to the right of the original Hind III site. Under the ...

1982-04-01

263

Hemoglobin of mice with radiation-induced mutations at the hemoglobin loci

The production of cellulolytic enzymes from fungi has been extensively studied. Several mutants of Trichoderma reesei were selected. Most of the studies were carried out on T. reesei, T. viride, T. harzianum, Penicillium funiculosum, Altemaria alternata. Aspergillus phoenicis, A. ustus, A. tamarii, A. japonicus, and A. niger. T. koningii is one of the most active producers of the so-called C, factor, which is indispensable for the rapid and extensive attack on crystal-line cellulose. However, Trichodenna is known to excrete only small amounts of {beta}-glucosidase. Therefore, Trichoderma is supplemented with {beta}-glucosidase from Aspergillus to increase the saccharification rate of cellulose to glucose as the main sugar. Induction of mutations in Trichodenna spp. rather than T. viride as a tool for the enhancement of {beta}-glucosidase activity was reported. Unfortunately, T. reesei is a poor producer of {beta}-glucosidase. On the other hand, T. harzianum M{sub ...

1991-12-31

264

GROWTH REGULATION IN ROUS SARCOMA VIRUS INFECTED CHICKEN EMBRYO FIBROBLASTS: THE ROLE OF THE src GENE

Chemical analyses were done on the abnormal hemoglobins of the five (101 x SEC)F_1 offspring of X- irradiated adult SEC mice to determine which hemoglobin genes were expressed in each hemoglobin variant. Three offspring of irradiated SEC males did not express either of the two kinds of #alpha#-chains normally found in all SEC mice. The deficient #alpha#-chain synthesis caused these mice to exhibit an #alpha#-thalassemia similar to human #alpha#-thalassemia. Scanning electron microscopy was used to show that many erythrocytes of mice with #alpha#-thalassemia have bizarre shapes; e.g. many erythrocytes appeared flattened or had thorny projections (acanthocytes). One mutant with a tandem duplication of a segment of chromosome 7 (site of locus determining #beta#-chain structure) produced twice as much SEC as 101 #beta#-chain polypeptides. One mutant that probably arose by non-disjunction of chromosome 7's in its unirradiated 101 mother and loss of ...

265

Endonuclease IV of Escherichia coli is induced by paraquat

We report here a study of the mechanisms leading to loss of growth control in chicken embryo fibroblasts transformed by Rous sarcoma virus (RSV). We have been particularly concerned with the role of the src gene in this process, and have used RSV mutants temperature sensitive (ts) for transformation to investigate the nature of the growth regulatory lesion. The two principal findings were (1) the stationary phase of the cell cycle (G{sub 1}) in chick embryo fibroblasts seems to have two distinct regulatory compartments (using the terminology of Brooks et al. we refer to these as 'Q' and 'A' states). When rendered stationary at 41.5 C by serum deprivation, normal cells enter a Q state, but cells infected with the ts-mutant occupy an A state. (2) Whereas normal cells can occupy either state depending on culture conditions, the ts-infected cells, at 41.5 C, do not seem to enter Q even though a known src gene ...

1980-07-01

266

Ectopic expression of wild-type or a dominant-negative mutant of transcription factor NTF-1 disrupts normal Drosophila development.

The addition of paraquat (methyl viologen) to a growing culture of Escherichia coli K-12 led within 1 hr to a 10- to 20-fold increase in the level of endonuclease IV, a DNase for apurinic/apyrimidinic sites. The induction was blocked by chloramphenicol. Increases of 3-fold or more were also seen with plumbagin, menadione, and phenazine methosulfate. H_2O_2 produced no more than a 2-fold increase in endonuclease IV activity. The following agents had no significant effect: streptonigrin, nitrofurantoin, tert-butyl hydroperoxide, #gamma# rays, 260-nm UV radiation, methyl methanesulfonate, mitomycin C, and ascorbate. Paraquat, plumbagin, menadione, and phenazine methosulfate are known to generate superoxide radical anions via redox cycling in vivo. A mutant lacking superoxide dismutase was unusually sensitive to induction by paraquat. In addition, endonuclease IV could be induced by merely growing the mutant in pure O_2. The levels of endonuclease ...

267

Development of a novel mouse tk{sup +/-} embryonic stem cell line for use in mutagenicity studies

The Drosophila melanogaster tissue-specific transcription factor NTF-1 was originally identified in vitro as a protein that could bind to and activate transcription from the Dopa decarboxylase (Ddc) gene. A structure-function analysis of NTF-1 led to the identification of a discrete amino-terminal activation domain. Here, we report that an NTF-1 mutant lacking the activation domain acts as a trans-dominant inhibitor of NTF-1 activation in tissue culture cells by forming inactive heterodimers with the full-length protein. Ectopically expressing this dominant-negative protein or the full-length protein in developing Drosophila embryos leads to dire developmental consequences. Overexpressing the trans-dominant NTF-1 leads to lethality, while overexpressing full-length NTF-1 results in both lethality and morphogenetic defects. Our results suggest that both the activity and the regulation of NTF-1 are critical for viability and proper development of the fly.ImagesFig. ...

1993-11-15

268

Methods to improve the fertility of poinsettia

A tk{sup +/-} mouse embryonic stem (ES) cell line, designated 1G2, has been created in which one allele of the thymidine kinase (tk) gene was inactivated by targeted homologous recombination. This line is an analog of the mouse lymphoma tk{sup +/-} L5178Y cell line, which is used widely to assess the mutagenicity of chemical agents. Treatment of 1G2 cells with the alkylating agent N-ethyl-N-nitrosourea (ENU) resulted in a dose-related increase in tribluorothymidine-resistant colonies. Mutant frequencies of 152 and 296 per 10{sup 6} cells were determined for 0.1 and 0.3 mg/ml doses of ENU, compared with a spontaneous mutant frequency of 15 per 10{sup 6} cells. The data indicate that tk{sup +/-} 1G2 ES cells may be useful for the creation of a transgenic mouse model for assessing in vivo mutation using an endogenous autosomal gene. 45 refs., 2 figs., 1 tab.

1996-12-31

269

British Library Electronic Table of Contents (United Kingdom)

`Success' or `Red Splendor' plants propagated by shoot tip culture or embryogenesis had higher pollen germination than those propagated by cutting. All clones of `Pepride', `Peter Star' and `Nobel Star' propagated by cutting or by embryogenesis or shoot tip culture did not have viable pollen. `Peter Star' mutants through mutagenesis could recover pollen viability. When both parents were propagated by tissue culture, fruit set increased compared to when one or both parents were propagated by cuttings. Furthermore, the number of the harvested seeds doubled per pollination set, when the tissue culture parents were used instead of cutting-propagation plants.

2008-01-01

270

Emulsans. [Acinetobacter sp. ATCC 31012

Analysis of the tet repressor-operator interactions using the uracil-DNA glycosylase footprinting system

The production and uses are described for extracellular microbial polysaccharides (generically called emulsans) and for a new class of extracellular microbial protein-associated lipopolysaccharides (collectively called alpha-emulsans) produced by Acinetobacter Sp. ATCC 31012, its mutants or recombinants. Also included are the deproteinized lipopolysaccharides (collectively called apoemulsans) obtained from such emulsans, as well as to the divalent metal, ammonium, and quaternary ammonium salts of such emulsans and apoemulsans. The materials can be used (1) in cleaning oil-contaminated vessels used to transport or store crude oil or petroleum fractions in such a manner that the residual oil may be recovered for fuel value or for refining and (2) in enhanced oil recovery.

1983-07-05

271

Vertical and Horizontal Variations in the Physiological Diversity of the Aerobic Chemoheterotrophic Bacterial Microflora in Deep Southeast Coastal Plain Subsurface Sediments

The tet repressor regulated expression of the Tn-10-encoded tetracycline resistance determinant in a tetracycline-dependent manner. In the absence of tetracycline, the tet repressor binds as a dimer to the 19-base-pair palindromic tet operator sequence. Amino acid homologies and genetic studies with trans-dominant mutants suggest that sequence-specific recognition of the tet operator involves the extensively studied helix-turn-helix motif. We have used the uracil-DNA glycosylase (UDG) footprinting systems to identify thymine contacts in the tet operator that are essential for the formation of tet repressor-operator complexes.

1994-12-31

272

Telavancin versus Standard Therapy for Treatment of Complicated Skin and Skin Structure Infections Caused by Gram-Positive Bacteria: FAST 2 Study

Aerobic chemoheterotrophic bacteria were isolated from surface soils and coastal plain subsurface (including deep aquifer) sediments (depths to 265 m) at a study site near Aiken, S.C., by plating on...Full Text Available

1989-05-01

273

Staphylococcus aureus Enterotoxin D Is Secreted in Milk and Stimulates Specific Antibody Responses in Cows in the Course of Experimental Intramammary Infection

Telavancin is a bactericidal lipoglycopeptide with a multifunctional mechanism of action. We conducted a randomized, double blind, active-control phase II trial. Patients ≥18 years of age with...Full Text Available

2006-03-01

274

Radiation higienization possibility and perspectives

An enterotoxin D (SED)-producing strain of Staphylococcus aureus was used to infect one mammary gland of each of 17 lactating dairy cows. All glands became infected and shed bacteria...Full Text Available

2006-06-01

275

Quality engineering and control. Annual progress report, January-December 1981

Food irradiation is the process of exposing food to an ionizing energy to kill harmful bacteria and other organisms and extend shelf-life. It is a safe process and has been approved by some 50 countries worldwide and applied commercially in the USA, Japan, China and several European countries for many years. Trends law regulations and new applications in Europe and another countries has been described. (author)

2005-09-07

276

One-carbon metabolism in methanogenic bacteria: analysis of short-term fixation products of 14CO2 and 14CH3OH incorporated into whole cells.

Brief summaries are given of research carried out in the following areas: absorption spectroscopy of titanium, niobium, and molybdenum in uranium alloys; atomic absorption spectroscopy of selenium in stainless steel, computer program improvements for spectrophotometer control, and detection of beryllium in stack gases; electrolysis for inactivation of bacteria in cooling-tower water; improved solvent analysis by gas chromatography; sequential radionuclide separation for various sample matrices; progress on an electron microprobe analyzer; and miscellaneous projects.

277

Moessbauer studies of the molybdenum-iron-protein in the nitrogenase of Xanthobacter autotrophicus GZ 29. Moessbaueruntersuchungen am Molybdaen-Eisen-Protein der Nitrogenase von Xanthobacter Autotrophicus GZ 29

Methanobacterium thermoautotrophicum, M. ruminantium, and Methanosarcina barkeri were labeled with 14CO2 (14CO2 + H14CO3- + 14CO32-) for from 2 to 45 s. Radioactivity was recovered in coenzyme M derivatives,...Full Text Available

1978-10-01

278

Mercury Removal, Methylmercury Formation, and Sulfate-Reducing Bacteria Profiles in Wetland Mesocosms Containing Gypsum-Amended Sediments and Scirpus californicus

Biological cells of the nitrogen fixating bacteria Xanthobacter autotrophicus GZ 29 have been cultivated with 57-Fe, and from the nitrogenase of these cells the 57-Fe marked molybdenum-iron-protein is extracted. The Moessbauer spectra of this enzyme show that the structure of the iron cluster is similar to the structure in the molybdenum-iron-proteins of Azotobacter vinelandii, Klebsiella pneumoniae or Clostridium pasteurianum.

1983-05-01

279

Ecology and resistance of Moraxella-Acinetobacter

A pilot-scale model was constructed to determine if a wetland treatment system (WTS) could effectively remove low-level mercury from an outfall located at the Department of Energy's Savannah River Site.

2001-03-02

280

Crystallization and preliminary X-ray analysis of three dUTPases from Gram-positive bacteria

The diverse microenvironments of foods, changing with processing and preservation, might provide conditions that would enhance the growth of microorganisms which are the principal cause of spoilage, off-odor and unpleasant flavor in foods. Radiation is a potential process which may provide a product with far superior microbial quality for food preservation, by reduction of microbial population; elimination of food-borne pathogens; extension of shelf-life; and reduction of spoilage. The aim of irradiation at low dose level is to eliminate certain microorganisms, especially spoilage types and those of public health significance. But, the radurization dose allows the outgrowth of radioresistant bacteria. Certain strains of Moraxella-Acinetobacter (M-A) groups have been recognized as radioresistant bacteria (Welch and Maxcy, 1975), which may have gone unnoticed by food microbiologists, since these bacteria have not been ...

1977-01-01

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281

Comparative In Vitro Activity Profiles of Novel Bis-Indole Antibacterials against Gram-Positive and Gram-Negative Clinical Isolates?

All organisms examined to date possess a dUTPase that performs the important function of efficiently hydrolyzing dUTP to dUMP in order to prevent the incorporation of dUTP into DNA. Three putative dUTPases...Full Text Available

282

Campylobacter jejuni Fatty Acid Synthase II: Structural and functional analysis of ?-hydroxyacyl-ACP dehydratase (FabZ)

Antimicrobial susceptibilities of 233 Gram-positive and 180 Gram-negative strains to two novel bis-indoles were evaluated. Both compounds were potent inhibitors of Gram-positive bacteria, with MIC₉₀...Full Text Available

2010-09-01

283

Biosorption for the separation of radionuclides from drainage and process waters of the uranium mining industry

Fatty acid biosynthesis is crucial for all living cells. In contrast to higher organisms, bacteria use a type II fatty acid synthase (FAS II) composed of a series of individual proteins, making...Full Text Available

2009-03-06

284

Roles of the #beta# 146 histidyl residue in the molecular basis of the Bohr Effect of hemoglobin: A proton nuclear magnetic resonance study

Biosorption means the storage of substances at the cell envelope. Different microbial biomasses were tested for the separation of radionuclides from mining waters. Results of a pilot plant demonstrate the ability of these techniques for water cleaning processes. An effluent concentration of lower than 1 mg/l (in most cases 0.1 mg/1) could be realized in a pilot plant by using pure cells of a methylotrophic strain of bacteria as well as using of a fungal mycelia.

1995-12-31

285

Research work on mutation breeding in Egypt during the 1980s

Assessment of the roles of the carboxyl-terminal #beta#146 histidyl residues in the alkaline Bohr effect in human and normal adult hemoglobin by high-resolution proton nuclear magnetic resonance spectroscopy requires assignment of the resonances corresponding to these residues. By a careful spectroscopic study of human normal adult hemoglobin, enzymatically prepared des(His146#beta#)-hemoglobin, and the mutant hemoglobins Cowtown (#beta#146His #-># Leu) and York (#beta#146His #-># Pro), the authors have resolved some of these conflicting results. By a close incremental variation of pH over a wide range in chloride-free 0.1 M N-(2-hydroxyethyl)piperazine-N'-2-ethanesulfonic acid buffer, a single resonance has been found to be consistently missing in the proton nuclear magnetic resonance spectra of these hemoglobin variants. The results indicate that the contribution of the #beta#146 histidyl residues is 0.52 H"+/hemoglobin tetramer at pH 7.6, markedly less ...

286

Use of DNA probes to study tetracycline resistance determinants in gram-negative bacteria from swine

The research work carried out on mutation breeding in Egypt during the 1980s is summarized. Several mutations have been developed in bread wheat, maize, rice and barley. A higher yield, tolerance to salinity, shorter types and earliness were obtained after use of different mutagens and growth regulators. Great attention has been paid to the fababean and chickpea, particularly in improving their quality and quantity of protein, and their resistance to insect weevils such as Callosobruchus sp. Tolerance or resistance to broom rape has also been reported. Various grain legumes such as lentil, pea, cowpea, bean, fenugreek and lupin received some attention. Mutation work on fibre crops such as cotton, kenaf and flax has led to some promising results. Zero type, glandless and early maturing mutants were obtained in cotton, and early flowering, high yielding (fibre or oil) mutants in flax. Some attention has been given to oil crops such as sesame, ...

1990-06-18

287

The anaerobic digestion process

Specific {sup 32}P-labeled DNA probes were prepared and used to evaluate the distribution of tetracycline resistance determinants carried by gram-negative enteric bacteria isolated from pigs in 3 swine herds with different histories of antibiotic exposure. Plasmid DNA, ranging in size from 2.1 to 186 Kb, was observed in over 84% of 114 isolates studied. Two of 78 tetracycline resistant strains did not harbor plasmids. The DNA probes were isolated from plasmids pSL18, pRT29/Tn10, pBR322 and pSL106, respectively, and they represented class A, B, C and D tetracycline resistance determinants. Hybridization conditions using 0.5X SSPE at 65{degrees}C minimize cross-hybridization between the different class of tetracycline resistance genes. Cross-hybridization between class A and class C determinants could be distinguished by simultaneous comparison of the intensity of their hybridization signals. Plasmids from over 44% of the tetracycline resistant isolates did not ...

1989-01-01

288

Test of electron beam technology on Savannah River Laboratory low-activity aqueous waste for destruction of benzene, benzene derivatives, and bacteria

The microbial process of converting organic matter into methane and carbon dioxide is so complex that anaerobic digesters have long been treated as {open_quotes}black boxes.{close_quotes} Research into this process during the past few decades has gradually unraveled this complexity, but many questions remain. The major biochemical reactions for forming methane by methanogens are largely understood, and evolutionary studies indicate that these microbes are as different from bacteria as they are from plants and animals. In anaerobic digesters, methanogens are at the terminus of a metabolic web, in which the reactions of myriads of other microbes produce a very limited range of compounds - mainly acetate, hydrogen, and formate - on which the methanogens grow and from which they form methane. {open_quotes}Interspecies hydrogen-transfer{close_quotes} and {open_quotes}interspecies formate-transfer{close_quotes} are major mechanisms by which methanogens obtain their ...

1996-01-01

289

Synthesis, characterization and biological evaluation of mononuclear Co(II), Ni(II), Cu(II) and Pd(II) complexes with new N2O2 Schiff base ligands.

High energy radiation was studied as a means for destroying hazardous organic chemical wastes. Tests were conducted at bench scale with a {sup 60}Co source, and at full scale (387 l/min) with a 1.5 MV electron beam source. Bench scale tests for both benzene and phenol included 32 permutations of water quality factors. For some water qualities, as much as 99.99% of benzene or 90% of phenol were removed by 775 krads of {sup 60}Co irradiation. Full scale testing for destruction of benzene in a simulated waste-water mix showed loss of 97% of benzene following an 800 krad dose and 88% following a 500 krad dose. At these loss rates, approximately 5 Mrad of electron beam irradiation is required to reduce concentrations from 100 g/l to drinking water quality (5 {mu}g/l). Since many waste streams are also inhabited by bacterial populations which may affect filtering operations, the effect of irradiation on those populations was also studied. {sup 60}Co and electron beam irradiation were both ...

1993-08-01

290

Influence of substrates on nitrogen removal performance and microbiology of anaerobic ammonium oxidation by operating two UASB reactors fed with different substrate levels.

New tetradentate N(2)O(2) donor Schiff bases and their mononuclear Co(II), Ni(II), Cu(II), and Pd(II) complexes were synthesized and characterized extensively by IR, (1)H-, (13)C-NMR, mass, ESR, conductivity measurements, elemental and thermal analysis. Specifically the magnetic and electronic spectral measurements demonstrate the octahedral structures of cobalt(II), nickel(II) complexes and square planar geometries of copper(II), palladium(II) complexes. All the ligands and complexes were screened for their in vitro antibacterial activity against two gram-positive bacteria (Bacillus subtilis, Staphylococcus aureus) and two gram-negative bacteria (Escherichia coli, Klebsiella pneumonia). In this study, Pd(II) complexes exhibited potent antibacterial activity against B. subtilis, S. aureus whereas other metal complexes also exerted good activity towards all tested strains even than standard drugs streptomycin and ampicillin. PMID:21297294

2011-02-01

291

Gene discovery in the Acanthamoeba castellanii genome

Both ammonium and nitrite act as substrates as well as potential inhibitors of anoxic ammonium-oxidizing (Anammox) bacteria. To satisfy demand of substrates for Anammox bacteria and to prevent substrate inhibition simultaneously; two strategies, namely high or low substrate concentration, were carefully compared in the operation of two Anammox upflow anaerobic sludge blanket (UASB) reactors fed with different substrate concentrations. The reactor working at relatively low influent substrate concentration (NO(2)(-)-N, 240 mg-NL(-1)) was shown to avoid the inhibition caused by nitrite and free ammonia. Using the strategy of low substrate concentration, a record super high volumetric nitrogen removal rate of 45.24 kg-Nm(-3) day(-1) was noted after the operation of 230 days. To our knowledge, such a high value has not been reported previously. The evidence from transmission electron microscopy (TEM) showed that the morphology and ultrastructure of ...

2010-04-13

292

Development and application of bio-sensor. Production of ammonia sensor

Acanthamoeba castellanii is a free-living amoeba found in soil, freshwater, and marine environments and an important predator of bacteria. Acanthamoeba castellanii is also an opportunistic pathogen of clinical interest, responsible for several distinct diseases in humans. In order to provide a genomic platform for the study of this ubiquitous and important protist, we generated a sequence survey of approximately 0.5 x coverage of the genome. The data predict that A. castellanii exhibits a greater biosynthetic capacity than the free-living Dictyostelium discoideum and the parasite Entamoeba histolytica, providing an explanation for the ability of A. castellanii to inhabit adversity of environments. Alginate lyase may provide access to bacteria within biofilms by breaking down the biofilm matrix, and polyhydroxybutyrate depolymerase may facilitate utilization of the bacterial storage compound polyhydroxybutyrate as a food source. Enzymes for the ...

2005-08-01

293

Antenna organization in green photosynthetic bacteria. Progress report, March 1986--February 1987

The objectives of this study are to make a biosensor on a trial basis which can instantaneously measure the nitrogen in wastewater, and to develop a wastewater treatment system which is capable of on-line measurement and controlling. The system provides easier operational control relating to such a high efficient treatment as the removal of nitrogen content in wastewater, serving as a solution to the eutrophication problem. It can be applied also to the analysis of fertilizer components for agriculture. Ammonia oxidizing bacteria were immobilized with cellulose acetate film, which is mounted on a diaphragm type oxygen electrode to make a sensor, and its responsibility was studied. The gradient is slow in high concentration but sharp in low concentration, and it seems possible to use it for the measurement for less than 20 ppm nitrogen concentration. The dependence of the sensor including electrodes and activity of bacteria on temperature is ...

1989-08-01

294

The effects of cefazolin on cirrhotic patients with acute variceal hemorrhage after endoscopic interventions

This project is concerned with the structure and function of the unique antenna system found in the green photosynthetic bacteria. The antenna system in these organisms is contained within a vesicle known as a chlorosome, which is attached to the cytoplasmic side of the cell membrane. Additional antenna pigments and reaction centers are contained in integral membrane proteins. Energy absorbed by the bacteriochlorophyll c (BChl c) pigments in the chlorosome is transferred via a ``baseplate`` array of BChl a antenna pigments into the membrane and to the reaction center. This system is similar in some respects to the phycobilisome antenna system found in cyanobacteria and some types of algae, in that a membrane-associated structure absorbs light and transfers it to the membrane where conversion to chemical energy takes place. However, the overall structure, the type of pigments utilized and the nature of the proteins in these two types of membrane-associated antenna ...

1987-12-31

295

British Library Electronic Table of Contents (United Kingdom)

Background The American Association for the Study of Liver Diseases (AASLD) guidelines recommend that antibiotic prophylaxis should be instituted in any patient with cirrhosis and gastrointestinal hemorrhage, and that oral norfloxacin, intravenous ciprofloxacin, and ceftriaxone are preferable. However, the antimicrobial spectrum of the first generation of cephalosporins (cefazolin) covers a wide range of bacteria species, including community-acquired strains of Escherichia coli and Klebsiella pneumoniae, but their efficacy as prophylactic antibiotics in cirrhotic patients with acute hemorrhage was seldom warranted in the literature. This study aimed to explore the effects of cefazolin on the outcome of cirrhotic patients with acute variceal hemorrhage after endoscopic interventions. Method...

2011-01-01

296

Effects of Acetate Competition, pH and Soil Structure on the Rates and Pathways of Methane Formation in Tropical Rain Forest Soils

Cell cultures are more sensitive than Saccharamoyces cervisiae tests for assessing the toxicity of aquatic pollutants

The C isotopic composition of CH4 emissions are strongly influenced by the pathway of CH4 formation. Contrary to data from other freshwater systems, soil gas and surface flux measurements made in the tropical rain forests of Puerto Rico strongly suggest that CH4 produced in these environments was derived from CO2 reduction, rather than from acetate consumption. This study explored the effects of bacterial competition for acetate, pH, and soil structure on the pathways of CH4 formation in tropical rain forest soils. Our goal was to test two principal hypotheses: (1) ferric iron-reducing bacteria out-competed methanogens for acetate, resulting in greater CO2 reduction rather than aceticlastic methanogenesis, and (2) the low pH of tropical rain forest soils favors CO2 reduction rather than aceticlastic methanogenesis. In addition, this study also investigated the effect of destroying soil aggregate structure on the pathways and rates of CH4 production. Ferric ...

2004-12-01

297

Antimicrobial potential of Glycyrrhiza glabra roots

Cultured fish and human cells have been used as bioassay systems for the evaluation of the toxicity of aquatic pollutants. Numerous assays using bacteria and yeast have also been used for such purposes. The authors report the toxicity of aquatic pollutants (Cd, Hg, and Ni), using cell culture systems and the yeast Saccharomyces cervisiae test. Cd, Hg, and Ni were chosen as model compounds of pollutants because the related toxicity is now fairly well established.

1988-07-01

298

British Library Electronic Table of Contents (United Kingdom)

The present study was aimed to investigate antimicrobial potential of Glycyrrhiza glabra roots. Antimycobacterial activity of Glycyrrhiza glabra was found at 500mg/mL concentration. Bioactivity guided phytochemical analysis identified glabridin as potentially active against both Mycobacterium tuberculosis H37Ra and H37Rv strains at 29.16mg/mL concentration. It exhibited antimicrobial activity against both Gram-positive and Gram-negative bacteria. Our results indicate potential use of licorice as antitubercular agent through systemic experiments and sophisticated anti-TB assay.

2008-01-01

299

Acceleration of Emergence of Bacterial Antibiotic Resistance in Connected Microenvironments.

Identification and characterization of noncoding small RNAs in Streptococcus pneumoniae serotype 2 strain D39.

The emergence of bacterial antibiotic resistance is a growing problem, yet the variables that influence the rate of emergence of resistance are not well understood. In a microfluidic device designed to mimic naturally occurring bacterial niches, resistance of Escherichia coli to the antibiotic ciprofloxacin developed within 10 hours. Resistance emerged with as few as 100 bacteria in the initial inoculation. Whole-genome sequencing of the resistant organisms revealed that four functional single-nucleotide polymorphisms attained fixation. Knowledge about the rapid emergence of antibiotic resistance in the heterogeneous conditions within the mammalian body may be helpful in understanding the emergence of drug resistance during cancer chemotherapy. PMID:21940899

2011-09-23

300

Microbiological Comparison of Core and Groundwater Samples Collected from a Fractured Basalt Aquifier with that of Dialysis Chamber Incubated in Situ

We report a search for small RNAs (sRNAs) in the low-GC, gram-positive human pathogen Streptococcus pneumoniae. Based on bioinformatic analyses by Livny et al. (J. Livny, A. Brencic, S. Lory, and M. K. Waldor, Nucleic Acids Res. 34:3484-3493, 2006), we tested 40 candidates by Northern blotting and confirmed the expression of nine new and one previously reported (CcnA) sRNAs in strain D39. CcnA is one of five redundant sRNAs reported by Halfmann et al. (A. Halfmann, M. Kovacs, R. Hakenbeck, and R. Bruckner, Mol. Microbiol. 66:110-126, 2007) that are positively controlled by the CiaR response regulator. We characterized 3 of these 14 sRNAs: Spd-sr17 (144 nucleotides [nt]; decreased in stationary phase), Spd-sr37 (80 nt; strongly expressed in all growth phases), and CcnA (93 nt; induced by competence stimulatory peptide). Spd-sr17 and CcnA likely fold into structures containing single-stranded regions between hairpin structures, whereas Spd-sr37 forms a base-paired structure. Primer ...

2010-01-01

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301

Microbial water diversion technique-designed for near well treatment in low temperature sandstone reservoirs in the North Sea

Microorganisms associated with fractured basalt core were compared to those suspended in groundwater pumped from the same well in the eastern Snake River Plain Aquifer (Idaho, USA). Two wells influenced to different degrees by a mixed-waste plume in the fractured basalt aquifer were examined. In one well, an array of dialysis cells filled with either deionized water or crushed basalt was equilibrated to compare the microorganisms collected in this fashion with those from core and groundwater samples collected in a traditional manner from the same well. Analyses were performed to characterize these samples and to provide a basis for comparison. These included total cell counts by microscopy; total biomass by phospholipid fatty acid analysis; enumerations of viable aerobic heterotrophs, groups of putative aerobic co-metabolic TCE-degraders and aerobic H2-oxidizing bacteria; mineralization of 14C- labeled acetate; and enrichments for dissimilatory iron-reducing ...

2004-04-01

302

Isolation of imidacloprid degrading bacteria from industrial sites

A Norwegian Research Program on Improved Oil Recovery (IOR) in North Sea reservoirs was launched in 1992. Microbial methods, applied in this context, is a part of this program. The scope, the methodological approach, and results from the three first years are presented. Water profile control, using biomass to block high permeable zones of a reservoir, has been investigated using nitrate-reducing bacteria in the injected sea water as plugging agents. Emphasis has been put on developing a process that does not have disadvantages secondary to the process itself, such as souring and impairment of the overall injectivity of the field. Data from continuous culture studies indicate that souring may successfully be mitigated by adding nitrite to the injected seawater. The morphology and size of generic-nitrate-reducing seawater bacteria have been investigated. Screening of growth-promoting nutrients has been carried out, and some sources were detected ...

1995-12-31

303

[Destruction of radioactive particles by strains of Cladosporium cladosporoides (FRES.) de Vries].

Immidacloprid is a cyclodiene organochlorine used as an insecticide all over the world and possessing a serous environmental threat. It is mostly used for cotton insects (bollworm, aphid and white fly). For isolation of imidacloprid degrading bacteria, two soil samples were collected from industrial contaminated sites of Kala Shah Kahu district sheikupura, having ten year history of use. Soil samples were analyzed by measuring pH and electric conductivity. The isolation of imidacroprid degrading bacteria was performed by enrichment technique. Eight bacterial strains, S/sub 1-a/ S/2-2-b/ S/2-c/ S/2-d/ S/2-e/ S/sub 2-f/ and S/sub 2-g/ and S/sub e-a/ were isolated on the basis of their colony morphologies. The purified colonies were characterized morphologically, physiologically and biochemically. Gram staining was done and Gram negative strain were confirmed on MacConkey agar and Eosin Methylene Blue. Bacterial strains were also checked for ...

304

Wnt/b-catenin signal pathway stabilizes APP intracellular domain (AICD) and promotes its transcriptional activity

Reactions on the ionizing radiation of 14 Cladosporium cladosporioides strains were studied. Only 5 of them displayed radiotropizm. The ability of C. cladosporioides strains 4 and 5 with positive radiotropizm and museum C. cladosporioides strain 396 and its alb-mutant SM without positive radiotropizm to destruct radioactive particles of Chernobyl and explosion origin was studied. Two ways of radioactive particles destruction by C. cladosporioides were established, one of them is a direct way by fungal overgrowth of hot particles and the second one an indirect way only by fungal metabolites. Mycelium of the studied C. cladosporioides strains sorbed radionuclides from radioactive particles during cultivation on the liquid and agarized media. No certain inclinations of the individual strains to accumulation of radionuclides 137Cs or 152Eu were ascertained. PMID:12664550

305

British Library Electronic Table of Contents (United Kingdom)

Amyloid precursor protein (APP), a key protein in pathogenesis of Alzheimer's disease (AD), is a type I transmembrane protein which can be cleaved by b- and g-secretase to release the amyloidogenic b-amyloid peptides (Ab) and the APP intracellular domain (AICD). While Ab has been widely believed to initiate pathogenic cascades culminating AD, the physiological functions and regulations of AICD remain elusive. In present study, endogenous AICD was demonstrated to be increased by canonical Wnt signal. Instead of due to g-secretase activity, enhanced AICD expression was found due to the increased protein stability by Wnt/b-catenin. b-Catenin was demonstrated to be an associating partner of AICD, capable of promoting AICD mediated transcriptional activity. Investigation by AICD mutants proved ...

2011-01-01

306

Unfolding analysis of the mature and unprocessed forms of Bacillus licheniformis ?-glutamyltranspeptidase

British Library Electronic Table of Contents (United Kingdom)

Bacillus licheniformis ?-glutamyltranspeptidase (BlGGT) undergoes an autocatalytic process to generate 44.9 and 21.7?kDa subunits; however, a mutant protein (T399A) loses completely the processing ability and mainly exists as a precursor. For a comprehensive understanding of their structural features, the biophysical properties of these two proteins were investigated by circular dichroism and fluorescence spectroscopy. Tryptophan fluorescence and circular dichroism spectra were nearly identical for BlGGT and T399A, but unfolding analyses revealed that these two proteins had a different sensitivity towards temperature- and guanidine hydrochloride (GdnHCl)-induced denaturation. BlGGT and the unprocessed T399A displayed T m values of 61.4?C and 68.1?C, respectively, and thermal unfolding of b...

2011-01-01

307

UV inactivation: Combined effects of UV radiation and xenobiotics in two strains of Saccharomyces

Transformation by complementation of an adenine auxotroph of the lignin-degrading basidiomycete Phanerochaete chrysosporium

The effects of eight chemicals on the inactivation rate of ultraviolet radiation on the colony building capabilities of two strains of Saccharomyces cervisae - a wild type strain and a mutant deficient in excision repair - were studied. The insecticide methoxychlor, the herbicide 2,4-dichlorophenoxyacetic acid, the fungicide pentachlorophenol and its metabolite tetrachlorohydroquinone, as well as the chemicals acrylonitrile and 2,3-dichloro-1-propene have no significant impact on the effects of UV radiation in Saccharomyces cerevisae. Depending on the concentration, trichloroethylene increases the sensitivity to UV radiation. The herbicide paraquat provides efficient protection against UV radiation at concentrations where a toxic effect cannot be observed even without UV. The results were rather similar for both strains. (orig.).

308

R46 and pKM101 plasmid-mediated resistance to ionizing radiation in Escherichia coli

Swollen basiodiospores of an adenine auxotroph of Phanerochaete chrysosporium were protoplasted with Novozyme 234 and transformed to prototrophy by using a plasmid containing the gene for an adenine biosynthetic enzyme from Schizophyllum commune. Transformation frequencies of 100 transformants per {mu}g of DNA were obtained. Southern blot analysis of DNA extracted from transformants demonstrated that plasmid DNA was integrated into the chromosomal DNA in multiple tandem copies. Analysis of conidia and basiodiospores from transformants demonstrated that the transforming character was mitotically and meiotically stable on both selective and nonselective media. Genetic crosses between double mutants transformed for adenine prototrophy and other auxotrophic strains yielded Ade{sup {minus}} progeny, which indicated that integration occurred at a site(s) other than the resident adenine biosynthetic gene.

1989-02-01

309

Pigpen, a nuclear coiled body component protein, is involved in angiogenesis

The ability of the R46 R factor and its derivative pKM101 to modify sensitivity to "6"0Co #gamma# radiation was studied. In Escherichia coli K12 both plasmids enhanced bacterial survival after "6"0Co #gamma# irradiation. This effect was dependent on recA"+ genotype but not on recB"+, recB"+recC"+, and recF"+ genotypes. 5-Fluorouracil eliminated the R46 R factor from the parent and its rec"- mutant strains. These strains lost not only the antibiotic resistance coded for R46 R factor but their radioresistance as well.

310

British Library Electronic Table of Contents (United Kingdom)

We previously reported that puromycin-insensitive leucyl-specific aminopeptidase (PILSAP) is required for vascular endothelial growth factor (VEGF)- and basic fibroblast growth factor (bFGF)-induced angiogenesis and for endothelial differentiation from embryonic stem (ES) cells via the aminopeptidase activity of PILSAP. In this study, we searched for molecules that function during angiogenesis with PILSAP. We performed proteome analysis of nuclear extracts from embryoid bodies (EBs) made from ES cells transfected with mutant PILSAP lacking aminopeptidase activity and mock EBs. We identified pigpen, a 67-kDa nuclear coiled body component protein. Immunoprecipitation and western blotting demonstrated the binding of PILSAP and pigpen in endothelial cells (ECs), and this interaction was enhanc...

2010-01-01

311

Photosynthetic energy storage efficiency in Chlamydomonas reinhardtii, based on microsecond photoacoustics

British Library Electronic Table of Contents (United Kingdom)

Using a novel, pulsed micro-second time-resolved photoacoustic (PA) instrument, we measured thermal dissipation and energy storage (ES) in the intact cells of wild type (WT) Chlamydomonas reinhardtii, and mutants lacking either PSI or PSII reaction centers (RCs). On this time scale, the kinetic contributions of the thermal expansion component due to heat dissipation of absorbed energy and the negative volume change due to electrostriction induced by charge separation in each of the photosystems could be readily distinguished. Kinetic analysis revealed that PSI and PSII RCs exhibit strikingly different PA signals where PSI is characterized by a strong electrostriction signal and a weak thermal expansion component while PSII has a small electrostriction component and large thermal expansion....

2011-01-01

312

Phenotyping in the archaea: optimization of growth parameters and analysis of mutants of Haloferax volcanii

British Library Electronic Table of Contents (United Kingdom)

Abstract A method to grow the halophilic archaeon Haloferax volcanii in microtiter plates has been optimized and now allows the parallel generation of very reproducible growth curves. The doubling time in a synthetic medium with glucose is around 6-h. The method was used to optimize glucose and casamino acid concentrations, to clarify carbon source usage and to analyze vitamin dependence. The characterization of osmotolerance revealed that after a lag phase of 24-h, H. volcanii is able to grow at salt concentrations as low as 0.7-M NaCl, much lower than the 1.4-M NaCl described as the lowest concentration until now. The application of oxidative stresses showed that H. volcanii exhibits a reaction to paraquat that is delayed by about 10-h. Surprisingly, only one of two amino acid auxotrophi...

2011-01-01

313

One-step RNA pathogen detection with reverse transcriptase activity of a mutated thermostable Thermus aquaticus DNA polymerase

British Library Electronic Table of Contents (United Kingdom)

We describe the cloning and characterization of a mutated thermostable DNA polymerase from Thermus aquaticus (Taq) that exhibits an increased reverse transcriptase activity and is therefore designated for one-step PCR pathogen detection using established real-time detection methods. We demonstrate that this Taq polymerase mutant (Taq M1) has similar PCR sensitivity and nuclease activity as the respective Taq wild-type DNA polymerase. In addition, and in marked contrast to the wild-type, Taq M1 exhibits a significantly increased reverse transcriptase activity especially at high temperatures (>60degreeC). RNA generally hosts highly stable secondary structure motifs, such as hairpins and G-quadruplexes, which complicate, or in the worst case obviate, reverse transcription (RT). Thus, RT at hi...

2010-01-01

314

N-acetoxy-N-2-acetylaminofluorene induced frameshift mutations: a comparison between the DNA modification spectrum and the mutation spectrum

Mutation breeding in leguminous crop plants

We describe the analysis of forward mutations induced in the tetracycline resistance gene of the plasmid pBR322 by directing the reaction of the carcinogen N-acetoxy-N-2-acetylaminofluorene (N-AcO-AAF) to a small restriction fragment (BamHI, SalI) that is located in the proximal part of the antibiotic-resistance gene. Mutant plasmids obtained both in wild type and excision repair deficient (uvrA) bacterial cells are compared. Preliminary data showing the distribution of the -AAF adducts along this restriction fragments are discussed in relation to the observed spectrum of mutations. 20 references, 4 figures.

315

Mitochondrial DNA background modulates the assembly kinetics of OXPHOS complexes in a cellular model of mitochondrial disease

Since it was introduced in the early 1940's, mutation breeding has been tested on many crops as modern plant breeding. Until now, more than seven hundred varieties have been developed by means of induced mutation, and many of them officially released and approved for registration. Hundreds of papers report the results of mutation breeding, and the characteristics of induced mutation in different kinds of crops were discussed for review purposes (Blixt and Gottschalk 1975, Gottschalk and Wolff 1983). Considering the results already obtained, it can be concluded that the kinds of induced mutation and their utilization vary from crop to crop. This paper summarizes and discusses the mutation characteristics and kinds on the induced mutants of leguminous plants that have been released.

1988-03-01

316

British Library Electronic Table of Contents (United Kingdom)

Lebers hereditary optic neuropathy (LHON), the most frequent mitochondrial disorder, is mostly due to three mitochondrial DNA (mtDNA) mutations in respiratory chain complex I subunit genes: 3460/ND1, 11778/ND4 and 14484/ND6. Despite considerable clinical evidences, a genetic modifying role of the mtDNA haplogroup background in the clinical expression of LHON remains experimentally unproven. We investigated the effect of mtDNA haplogroups on the assembly of oxidative phosphorylation (OXPHOS) complexes in transmitochondrial hybrids (cybrids) harboring the three common LHON mutations. The steady-state levels of respiratory chain complexes appeared normal in mutant cybrids. However, an accumulation of low molecular weight subcomplexes suggested a complex I assembly/stability defect, which was ...

2008-01-01

317

Mannose-specific interaction of Lactobacillus plantarum with porcine jejunal epithelium

British Library Electronic Table of Contents (United Kingdom)

Abstract Host-microorganism interactions in the intestinal tract are complex, and little is known about specific nonpathogenic microbial factors triggering host responses in the gut. In this study, mannose-specific interactions of Lactobacillus plantarum 299v with jejunal epithelium were investigated using an in situ pig Small Intestinal Segment Perfusion model. The effects of L. plantarum 299v wild-type strain were compared with those of two corresponding mutant strains either lacking the gene encoding for the mannose-specific adhesin (msa) or sortase (srtA; responsible for anchoring of cell surface proteins like Msa to the cell wall). A slight enrichment of the wild-type strain associated with the intestinal surface could be observed after 8 h of perfusion when a mixture of wild-type and...

2008-01-01

318

Levels of mesenchymal FGFR2 signaling modulate smooth muscle progenitor cell commitment in the lung

British Library Electronic Table of Contents (United Kingdom)

Fibroblast growth factor (FGF) signaling has been shown to regulate lung epithelial development but its influence on mesenchymal differentiation has been poorly investigated. To study the role of mesenchymal FGF signaling in the differentiation of the mesenchyme and its impact on epithelial morphogenesis, we took advantage of Fgfr2c+/? mice, which due to a splicing switch express Fgfr2b in mesenchymal tissues and manifest Apert syndrome-like phenotypes. Using a set of in vivo and in vitro studies, we show that an autocrine FGF10?FGFR2b signaling loop is established in the mutant lung mesenchyme, which has several consequences. It prevents the entry of the smooth muscle progenitors into the smooth muscle cell (SMC) lineage and results in reduced fibronectin and elastin deposition. Levels of...

2006-01-01

319

Ionizing radiation is a potent inducer of mitotic recombination in mouse embryonic stem cells

British Library Electronic Table of Contents (United Kingdom)

Maintenance of genomic integrity in embryonic cells is pivotal to proper embryogenesis, organogenesis and to the continuity of species. Cultured mouse embryonic stem cells (mESCs), a model for early embryonic cells, differ from cultured somatic cells in their capacity to remodel chromatin, in their repertoire of DNA repair enzymes, and in the regulation of cell cycle checkpoints. Using 129XC3HF1 mESCs heterozygous for Aprt, we characterized loss of Aprt heterozygosity after exposure to ionizing radiation. We report here that the frequency of loss of heterozygosity mutants in mESCs can be induced several hundred-fold by exposure to 5-10Gy of X-rays. This induction is 50-100-fold higher than the induction reported for mouse adult or embryonic fibroblasts. The primary mechanism underlying the...

2011-01-01

320

Inhibition of prepenetration processes of the powdery mildew Golovinomyces orontii on host inflorescence stems is reduced in the Arabidopsis cuticular mutant cer3 but not in cer1

British Library Electronic Table of Contents (United Kingdom)

The obligate biotrophic fungus Golovinomyces orontii causes powdery mildew (PM) disease on its host Arabidopsis thaliana. Most research on the G. orontii?Arabidopsis pathosystem uses rosette leaves as experimental materials, so little is known about the behavior of G. orontii on other Arabidopsis organs. We thus conducted microscopic analyses of the PM infection process on leaves, stems, fruits and roots of Arabidopsis. Adaxial and abaxial surfaces of mature rosette leaves supported G. orontii infection, but growth was somewhat suppressed on cauline leaves. Prepenetration processes (germination and appressorium formation) were strongly inhibited on stems, fruits and roots. To test the effect of alterations in the Arabidopsis cuticle on the inhibition of prepenetration processes on stems, w...

2011-01-01

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321

Inhibition of heat shock protein 27 (HspB1) tumorigenic functions by peptide aptamers

British Library Electronic Table of Contents (United Kingdom)

Human heat shock protein 27 (Hsp27, HspB1) is an anti-apoptotic protein characterized for its tumorigenic and metastatic properties, and now referenced as a major therapeutic target in many types of cancer. Hsp27 biochemical properties rely on a structural oligomeric and dynamic organization. Downregulation by small interfering RNA or inhibition with dominant-negative mutant have proven their efficiency to counteract the anti-apoptotic and protective properties of Hsp27. In this study, we report the isolation and characterization of Hsp27-targeted molecules interfering with its structural organization. Using the peptide aptamer (PA) strategy, we isolated PAs that specifically interact with Hsp27 and not with the other members of the small heat shock protein family. In mammalian cell cultur...

2011-01-01

322

Improving protein quality of soybean through induced mutations

Identification of mutations leading to the Lesch-Nyhan syndrome by automated direct DNA sequencing of in vitro amplified cDNA

Soybean is one of the most economical and nutritious food packed with basic nutrients that combat diseases stemming from mal- and under-nutrition. Despite its rich nutritional profile, use of soybean in food has been limited because soybean proteins are often associated with compounds, which could exert a negative impact on the nutritional quality of the protein. Trypsin inhibitor (TI) is one of the important anti-nutritional factors that exert negative effect by causing growth inhibition. Soybean cultivar VLS-2 was irradiated with 250 Gy gamma rays in a gamma cell (200) with 60Co source installed at BARC to induce mutations for low trypsin inhibitor content. Three mutants with lower levels of TI content were identified and can be utilized for developing elite varieties of soybean. (author)

2011-02-22

323

Identification of a functional nuclear export signal in the green fluorescent protein asFP499

The Lesch-Nyhan (LN) syndrome is a severe X chromosome-linked disease that results from a deficiency of the purine salvage enzyme hypoxanthine phosphoribosyltransferase (HPRT). The mutations leading to the disease are heterogeneous and frequently arise as de novo events. The authors have identified nucleotide alterations in 15 independently arising HPRT-deficiency cases by direct DNA sequencing of in vitro amplified HPRT cDNA. They also demonstrate that the direct DNA sequence analysis can be automated, further simplifying the detection of new mutations at this locus. The mutations include DNA base substitutions, small DNA deletions, a single DNA base insertion, and errors in RNA splicing. The application of these procedures allows DNA diagnosis and carrier identification by the direct detection of the mutant alleles within individual families affected by LN.

1989-03-01

324

Heparin binding sites on Ross River virus revealed by electron cryo-microscopy

The green fluorescent protein (GFP) asFP499 from Anemonia sulcata is a distant homologue of the GFP from Aequorea victoria. We cloned the asFP499 gene into a mammalian expression vector and showed that this protein was expressed in the human lymphoblast cell line Ramos RA1 and in the embryonic kidney 293T cell line (HEK 293T). In HEK 293T cells, asFP499 was localized mainly in the cytoplasm, suggesting that the protein was excluded from the nucleus. We identified _1_9_4LRMEKLNI_2_0_1 as a candidate nuclear export signal in asFP499 and mutated the isoleucine at position 201 to an alanine. Unlike the wildtype form, the mutant protein was distributed throughout the cytoplasm and nucleus. This is First report of a GFP that contains a functional NES.

2006-04-21

325

Generation of N-ethyl-N-nitrosourea-induced mouse mutants with deviations in hematological parameters

Cell surface glycosaminoglycans play important roles in cell adhesion and viral entry. Laboratory strains of two alphaviruses, Sindbis and Semliki Forest virus, have been shown to utilize heparan sulfate as an attachment receptor, whereas Ross River virus (RRV) does not significantly interact with it. However, a single amino acid substitution at residue 218 in the RRV E2 glycoprotein adapts the virus to heparan sulfate binding and expands the host range of the virus into chicken embryo fibroblasts. Structures of the RRV mutant, E2 N218R, and its complex with heparin were determined through the use of electron cryo-microscopy and image reconstruction methods. Heparin was found to bind at the distal end of the RRV spikes, in a region of the E2 glycoprotein that has been previously implicated in cell-receptor recognition and antibody binding.

2005-02-20

326

British Library Electronic Table of Contents (United Kingdom)

Research on hematological disorders relies on suitable animal models. We retrospectively evaluated the use of the hematological parameters hematocrit (HCT), hemoglobin (HGB), mean corpuscular hemoglobin (MCH), mean corpuscular hemoglobin concentration (MCHC), mean corpuscular volume (MCV), red blood cell count (RBC), white blood cell count (WBC), and platelet count (PLT) in the phenotype-driven Munich N-ethyl-N-nitrosourea (ENU) mouse mutagenesis project as parameters for the generation of novel animal models for human diseases. The analysis was carried out on more than 16,000 G1 and G3 offspring of chemically mutagenized inbred C3H mice to detect dominant and recessive mutations leading to deviations in the levels of the chosen parameters. Identification of animals exhibiting altered valu...

2011-01-01

327

Functional domain analysis of glass, a zinc-finger-containing transcription factor in Drosophila.

BzpF is a CREB-like transcription factor that regulates spore maturation and stability in Dictyostelium

The glass gene is required for proper photo-receptor differentiation during development of the Drosophila eye glass codes for a DNA-binding protein containing five zinc fingers that we show is a transcriptional activator. A comparison of the sequences of the glass genes from two species of Drosophila and a detailed functional domain analysis of the Drosophila melanogaster glass gene reveal that both the DNA-binding domain and the transcriptional-activation domain are highly conserved between the two species. Analysis of the DNA-binding domain of glass indicates that the three carboxyl-terminal zinc fingers alone are necessary and sufficient for DNA binding. We also show that a deletion mutant of glass containing only the DNA-binding domain can behave in a dominant-negative manner both in vivo and in a cell culture assay that measures transcriptional activation. PMID:7604032

1995-07-01

328

British Library Electronic Table of Contents (United Kingdom)

The cAMP response element-binding protein (CREB) is a highly conserved transcription factor that integrates signaling through the cAMP-dependent protein kinase A (PKA) in many eukaryotes. PKA plays a critical role in Dictyostelium development but no CREB homologue has been identified in this system. Here we show that Dictyostelium utilizes a CREB-like protein, BzpF, to integrate PKA signaling during late development. bzpF^- mutants produce compromised spores, which are extremely unstable and germination defective. Previously, we have found that BzpF binds the canonical CRE motif in vitro. In this paper, we determined the DNA binding specificity of BzpF using protein binding microarray (PBM) and showed that the motif with the highest specificity is a CRE-like sequence. BzpF is necessary to ...

2011-01-01

329

Bacteriophage P22 capsid size determination: Roles for the coat protein telokin-like domain and the scaffolding protein amino-terminus

British Library Electronic Table of Contents (United Kingdom)

Assembly of icosahedral capsids of proper size and symmetry is not understood. Residue F170 in bacteriophage P22 coat protein is critical for conformational switching during assembly. Substitutions at this site cause assembly of tubes of hexamerically arranged coat protein. Intragenic suppressors of the ts phenotype of F170A and F170K coat protein mutants were isolated. Suppressors were repeatedly found in the coat protein telokin-like domain at position 285, which caused coat protein to assemble into petite procapsids and capsids. Petite capsid assembly strongly correlated to the side chain volume of the substituted amino acid. We hypothesize that larger side chains at position 285 torque the telokin-like domain, changing flexibility of the subunit and intercapsomer contacts. Thus, a sing...

2011-01-01

330

Application of laser fluorimetry for determining the influence of a single amino-acid substitution on the individual photophysical parameters of a fluorescent form of a fluorescent protein mRFP1

A systematic RNAi screen reveals involvement of endocytic pathway in neuronal dysfunction in a-synuclein transgenic C. elegans

Individual photophysical parameters of the chromophore of a fluorescent protein mRFP1 and its two mutants (amino-acid substitution at position 66 - mRFP1/ Q66C and mRFP1/Q66S proteins) are determined. For this purpose, apart from conventional methods of fluorimetry and spectrophotometry, nonlinear laser fluorimetry is used. It is shown that the individual extinction coefficients of the chromophore of proteins correlate (correlation coefficient above 0.9) with the volume of the substituted amino-acid residue at position 66 (similar to the positions of the absorption, fluorescence excitation and emission maxima). (laser biology and medicine)

2009-03-31

331

British Library Electronic Table of Contents (United Kingdom)

Mutations or multiplications in a-synuclein gene cause familial forms of Parkinson disease or dementia with Lewy bodies (LB), and the deposition of wild-type a-synuclein as LB occurs as a hallmark lesion of these disorders, collectively referred to as synucleinopathies, implicating a-synuclein in the pathogenesis of synucleinopathy. To identify modifier genes of a-synuclein-induced neurotoxicity, we conducted an RNAi screen in transgenic C. elegans (Tg worms) that overexpress human a-synuclein in a pan-neuronal manner. To enhance the RNAi effect in neurons, we crossed a-synuclein Tg worms with an RNAi-enhanced mutant eri-1 strain. We tested RNAi of 1673 genes related to nervous system or synaptic functions, and identified 10 genes that, upon knockdown, caused severe growth/motor abnormalit...

2008-01-01

332

Transcriptional Profiling Analysis of the Global Regulator NorG, a GntR-Like Protein of Staphylococcus aureus.

Ionizing radiation-induced mutation of human cells with different DNA repair capacities

The GntR-like protein NorG has been shown to affect Staphylococcus aureus genes involved in the resistance to quinolones and ?-lactams, such as those encoding the NorB and AbcA transporters. To identify the target genes regulated by NorG, we carried out transcriptional profiling assays using S. aureus RN6390 and its isogenic norG::cat mutant. Our data showed that NorG positively affected the transcription of global regulators mgrA, arlS, and sarZ. The three putative drug efflux pump genes most positively affected by NorG were the NorB efflux pump (5.1-fold), the MmpL-like protein SACOL2566 (5.2-fold), and the BcrA-like drug transporter SACOL2525 (5.7-fold). The S. aureus predicted MmpL protein showed 53% homology with the MmpL lipid transporter of Mycobacterium tuberculosis, and the putative SACOL2525 protein showed 87% homology with the bacitracin drug transporter BcrA of Staphylococcus hominis. Two pump genes most negatively affected by NorG were NorC (4-fold) ...

2011-09-01

333

Apoptotic pathways as regulators of recombination

We have observed significant differences in the response to ionizing radiation of two closely related human cell lines, and now compare the effects on these lines of both low and intermediate LET radiation. Compared to TK6, WTK1 has an enhanced X-ray survival, and is also more resistant to cell killing by {alpha}-particles. The hprt locus is more mutable in WTK1 than in TK6 by both X-rays and {alpha}-particles. WTK1 is also more mutable by {alpha}-particles than by X-rays at the hprt locus. X-ray-induced mutation at the heterozygous tk locus in WTK1 is about 25 fold higher than in TK6, while {alpha}-particle-induced mutation is nearly 50 fold higher at this locus. Also, the slowly growing tk- mutants, which comprise the majority of spontaneous and X-ray-induced tk- mutants of TK6, were not induced significantly by {alpha}-particles. Previously, we showed that TK6 has a reduced capacity for recombination compared with WTK1, and therefore, these ...

1994-12-31

334

ATRX ADD domain links an atypical histone methylation recognition mechanism to human mental-retardation syndrome

Apoptosis, or programmed cell death (PCD), is a fundamental process that protects organismal integrity. In earlier work, we demonstrated that over-expression of either of two anti-apoptotic members of the BCL-2 family (BCL-2 or BCL-X L could elevate the frequency of radiation-induced mutations at the autosomal TK1 locus in human TK6 lymphoblasts that express wild-type TP53. Ectopic expression of BCL-X L also elevated the frequencies of double-strand break-induced gene conversion. The purpose of this study is to determine if BCL-2 family proteins promote radiation mutagenesis indirectly through their suppression of PCD, or whether the 'pro-mutagenic' function of these proteins can be separated from their anti-apoptotic function. We developed stable transfectants of TK6 cells that express a mutated form of BCL-X L with a single amino acid substitution in the BH1 domain that is known to interfere with the ability to suppress PCD (BCL-X L gly159ala). We also developed stable transfectants ...

2003-08-17

335

ATP-dependent partitioning of the DNA template into supercoiled domains by Escherichia coli UvrAB

ATR-X (alpha-thalassemia/mental retardation, X-linked) syndrome is a human congenital disorder that causes severe intellectual disabilities. Mutations in the ATRX gene, which encodes an ATP-dependent chromatin-remodeler, are responsible for the syndrome. Approximately 50% of the missense mutations in affected persons are clustered in a cysteine-rich domain termed ADD (ATRX-DNMT3-DNMT3L, ADD{sub ATRX}), whose function has remained elusive. Here we identify ADD{sub ATRX} as a previously unknown histone H3-binding module, whose binding is promoted by lysine 9 trimethylation (H3K9me3) but inhibited by lysine 4 trimethylation (H3K4me3). The cocrystal structure of ADD{sub ATRX} bound to H3{sub 1-15}K9me3 peptide reveals an atypical composite H3K9me3-binding pocket, which is distinct from the conventional trimethyllysine-binding aromatic cage. Notably, H3K9me3-pocket mutants and ATR-X syndrome mutants are defective in both H3K9me3 binding and ...

2011-07-19

336

Effects of human serum on bacterial competition with neutrophils for molecular oxygen.

The helicase action of the Escherichia coli UvrAB complex on a covalently closed circular DNA template was monitored using bacterial DNA topoisomerase I, which specifically removes negative supercoils. In the presence of E. coli DNA topoisomerase I and ATP, the UvrAB complex gradually introduced positive supercoils into the input relaxed plasmid DNA template. Positive supercoils were not produced when E. coli DNA topoisomerase I was replaced by eukaryotic DNA topoisomerase I or when both E. coli and eukaryotic DNA topoisomerases I were added simultaneously. These results suggest that like other DNA helix-tracking processes, the ATP-dependent action of the UvrAM complex on duplex DNA simultaneously generates both positive and negative supercoils, which are not constrained by protein binding but are torsionally strained. The supercoiling activity of UvrAB on UV-damaged DNA was also studied using UV-damaged plasmid DNA and a mutant UvrA protein that lacks the 40 ...

337

Whole Catchment Land Cover Effects on Water Quality in the Lower Kaskaskia River Watershed

A dialyzable factor(s) in human serum is known to stimulate gonococcal oxygen consumption. Its effect on other human pathogens was investigated. A 10% serum solution increased peak O2 consumption for Escherichia coli and Staphylococcus aureus to 157% (P less than 0.05) and 199% (P less than 0.02), respectively, of their O2 consumption when suspended in Hanks balanced salt solution, compared with a 356% increase for Neisseria gonorrhoeae with serum. Dialyzed serum lacked stimulatory capacity. Bacteria, serum, and neutrophils are often incubated to evaluate neutrophil bactericidal activity. Samples of 10(8) N. gonorrhoeae, S. aureus, and E. coli turned resazurin colorless (anaerobic conditions, Eh less than -42 mV) after 7.4, 13.3, and 15.1 min, respectively. Because neutrophil formation of reactive oxygen intermediates requires ambient O2, the effect of live bacteria and serum on this process was explored. After 5 min of incubation of 10(8) N. ...

1986-06-01

338

British Library Electronic Table of Contents (United Kingdom)

Agricultural runoff is a major non-point source pollutant and is the leading impairment of streams and rivers in the USA. This study examined the effects of agricultural, forest and urban land cover on water quality at the watershed level. Forty-three catchments ranging from 12 to 50?km2 were selected based on a land cover gradient within Lower Kaskaskia River Watershed in Illinois. Grab samples were collected and analyzed for nutrients, bacteria, and total suspended solids (TSS). Forest land cover was included in six of the ten regression models produced. Four of these regression models were for base flow conditions, suggesting that forest land cover had a significant impact on base flow water quality. Urban land cover was also included in six of the regression models. However, the majori...

2011-01-01

339

Testing an agent-based model of bacterial cell motility: How nutrient concentration affects speed distribution

British Library Electronic Table of Contents (United Kingdom)

We revisit a recently proposed agent-based model of active biological motion and compare its predictions with own experimental findings for the speed distribution of bacterial cells, Salmonella typhimurium. Agents move according to a stochastic dynamics and use energy stored in an internal depot for metabolism and active motion. We discuss different assumptions of how the conversion from internal to kinetic energy d(v) may depend on the actual speed, to conclude that d 2 v ? with either ? = 2 or 1 ? < 2 are promising hypotheses. To test these, we compare the model?s prediction with the speed distribution of bacteria which were obtained in media of different nutrient concentration and at different times. We find that both hypotheses are in line with the experimental observations, with ? bet...

2011-01-01

340

Studies on biosorption and toxicity of heavy metals in bacteria; Untersuchungen zur Biosorption und zur Toxizitaet von Schwermetallen auf Bakterien

Structure and antimicrobial activity relationship of quaternary N-alkyl chitosan derivatives against some plant pathogens

Biosorption behaviour of and toxic effects of heavy metals in submersed and immobilised microorganisms was studied in batches and in continuous processes in an airlift-recycle reactor. Nickel, cadmium, and zinc were used as heavy metals. (orig./VHE) [Deutsch] Am Beispiel einer Naphthalin-2-sulfonsaeure-abbauenden Kultur wurde das Biosorptionsverhalten und die toxische Wirkung von Schwermetallen auf submerse und immobilisierte Mikroorganismen im Batch-Ansatz und im kontinuierlichen Betrieb in einem Airlift-Schlaufenreaktor untersucht. Als Schwermetalle wurden Nickel, Cadmium und Zink eingesetzt. (orig./VHE)

1993-09-01

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341

British Library Electronic Table of Contents (United Kingdom)

In the present work, quaternary chitosans as water-soluble compounds were prepared based on three-step process. Schiff bases were firstly synthesized by the reaction between the amino groups of chitosan with aliphatic aldehydes followed by a reduction with sodium borohydride (NaBH4) to form N-(alkyl) chitosans. N,N,N-(dimethyl alkyl) chitosans were then obtained by a reaction of chitosan containing N-butyl, N-pentyl, N-hexyl, N-heptyl, and N-octyl substituents with methyl iodide. The compounds were characterized using IR and NMR spectroscopy. Subsequent experiments were conducted to test their antimicrobial activities against the most economic plant pathogenic bacteria of crown gall disease Agrobacterium tumefaciens, soft mold disease Erwinia carotovora, fungi of grey mold Botrytis cinerea...

2010-01-01

342

Sound climate installations. Gezonde klimaatinstallaties

Sodium-driven motor of the polar flagellum in marine bacteria Vibrio

An uncomfortable thermal climate, draft complaints and a bad airquality are often related to the climate installation. To avoid badfunctioning of the system a number of preconditions has to be fulfilledwith regard to design, planning and execution, adjustments, completion,control, maintenance and management of the installations. First threetypes of health problems in buildings are shortly discussed: buildingrelated illness, sick building syndrome and building or installationrelated complaints. Then some functions of the climate installationsare described: air filtration, filter classes and filter quality, aswell as investment costs for better filters. Next the causes for thecomplaints are dealt with: air conditioning, ventilation, air quality,and temperatures. Subsequently health affecting aspects in relation tothe climate systems are discussed: outdoor air pollution,microorganisms, bacteria (legionella pneumophila), allergies, ionneutralization and performance of ...

1989-10-01

343

British Library Electronic Table of Contents (United Kingdom)

The Na+-driven bacterial flagellar motor is a molecular machine powered by an electrochemical potential gradient of sodium ions across the cytoplasmic membrane. The marine bacterium Vibrio alginolyticus has a single polar flagellum that enables it to swim in liquid. The flagellar motor contains a basal body and a stator complexes, which are composed of several proteins. PomA, PomB, MotX, and MotY are thought to be essential components of the stator that are required to generate the torque of the rotation. Several mutations have been investigated to understand the characteristics and function of the ion channel in the stator and the mechanism of its assembly around the rotor to complete the motor. In this review, we summarize recent results of the Na+-driven motor in the polar flagellum of ...

2011-01-01

344

Serological Reactivity to Borrelia burgdorferi Sensu Lato in Dogs and Horses from Distinct Areas in Romania

British Library Electronic Table of Contents (United Kingdom)

Abstract Lyme disease is a perfect model of the complex relationship between host, vector, and the vector-borne bacteria. Both dogs and horses in Romania are exposed to infection. The aim of the present study was to assess the seroreactivity against Borrelia burgdorferi sensu lato in dogs and horses from different regions of Romania. 276 samples from dogs and 260 samples from horses located in different regions of Romania were analyzed by ELISA and IFA, respectively. The effect of several factors potentially affecting seroreactivity (location, age, gender, occupation, and vector exposition risk) was evaluated using Fisher's exact test (R 2.12.0). The overall prevalence of anti-Borrelia antibodies was 6.52% (18/276) in dogs, with a significantly higher positivity (46.15%, 6/13, p=0.0005) re...

2011-01-01

345

Sequences of versatile, broad-host-range vectors of the RK2 family.

Self-Organization in Space and Induced by Fluctuations

Plasmid pRK404-a smaller derivative of RK2-is a tetracycline-resistant broad-host-range vector that carries a multiple cloning site and the lacZ(alpha) peptide that enables blue/white selection for cloned inserts in Escherichia coli. We present herein the complete and annotated sequence of pRK404 and three related vectors-pRK437, pRK442, and pRK442(H). These derivatives have proven to be valuable tools for genetic manipulation in Gram-negative bacteria. The knowledge of their complete sequences will facilitate efficient future engineering of them and will enhance their general applicability to the design of genetic systems for use in organisms for which new genomic sequence data are becoming available.

2003-07-01

346

CERN Document Server

We present a simple discrete model for the non-linear spatial interaction ofdifferent kinds of ``subpopulations'' composed of identical moving entitieslike particles, bacteria, individuals, etc. The model allows to mimic a varietyof self-organized agglomeration and segregation phenomena. By relating it togame-theoretical ideas, it can be applied not only to attractive and repulsiveinteractions in physical and chemical systems, but also to the much richercombinations of positive and negative interactions found in biological andsocio-economic systems. Apart from investigating symmetric interactions relatedto a continuous increase of the ``overall success'' within the system(``self-optimization''), we will focus on cases, where fluctuations further orinduce self-organization, even though the initial conditions and theinteractions are assumed homogeneous in space (translation invariant).

2000-01-01

347

Root Hairs Play a Key Role in the Endophytic Colonization of Olive Roots by Pseudomonas spp. with Biocontrol Activity

British Library Electronic Table of Contents (United Kingdom)

The use of indigenous bacterial root endophytes with biocontrol activity against soil-borne phytopathogens is an environmentally-friendly and ecologically-efficient action within an integrated disease management framework. The earliest steps of olive root colonization by Pseudomonas fluorescens PICF7 and Pseudomonas putida PICP2, effective biocontrol agents (BCAs) against Verticillium wilt of olive (Olea europaea L.) caused by the fungus Verticillium dahliae Kleb., are here described. A gnotobiotic study system using in vitro propagated olive plants, differential fluorescent-protein tagging of bacteria, and confocal laser scanning microscopy analysis have been successfully used to examine olive roots?Pseudomonas spp. interactions at the single-cell level. In vivo simultaneous visualization...

2011-01-01

348

Review on the immunology of European sea bass Dicentrarchus labrax

British Library Electronic Table of Contents (United Kingdom)

European sea bass (Dicentrarchus labrax L.) is a marine species of great economic importance, particularly in Mediterranean aquaculture. However, numerous pathogenic viruses, bacteria, fungi and parasites affect the species, causing various infectious diseases and thereby leading to the most heavy losses in aquaculture production of sea bass. In this respect, knowledge on molecular and genetic mechanisms of resistance to pathogens and specific features of immune response against various infectious agents should greatly benefit the development of effective vaccines and proper vaccination strategies in marker-assisted selection of fish resistant to a range of infections. To date, genetic knowledge on sea bass immune regulatory genes responsible for resistance to pathogens is relatively poor ...

2007-01-01

349

Regulation and secretion of Xanthomonas virulence factors

British Library Electronic Table of Contents (United Kingdom)

Abstract Plant pathogenic bacteria of the genus Xanthomonas cause a variety of diseases in economically important monocotyledonous and dicotyledonous crop plants worldwide. Successful infection and bacterial multiplication in the host tissue often depend on the virulence factors secreted including adhesins, polysaccharides, LPS and degradative enzymes. One of the key pathogenicity factors is the type III secretion system, which injects effector proteins into the host cell cytosol to manipulate plant cellular processes such as basal defense to the benefit of the pathogen. The coordinated expression of bacterial virulence factors is orchestrated by quorum-sensing pathways, multiple two-component systems and transcriptional regulators such as Clp, Zur, FhrR, HrpX and HpaR. Furthermore, virule...

2010-01-01

350

Practical applications and feasibility of efflux pump inhibitors in the clinic-A vision for applied use

British Library Electronic Table of Contents (United Kingdom)

The world of antibiotic drug discovery and development is driven by the necessity to overcome antibiotic resistance in common Gram-positive and Gram-negative pathogens. However, the lack of Gram-negative activity among both recently approved antibiotics and compounds in the developmental pipeline is a general trend despite the fact that the plethora of covered drug targets are well-conserved across the bacterial kingdom. Such intrinsic resistance in Gram-negative bacteria is largely attributed to the activity of multidrug resistance (MDR) efflux pumps. Moreover, these pumps also play a significant role in acquired clinical resistance. Together, these considerations make efflux pumps attractive targets for inhibition in that the resultant efflux pump inhibitor (EPI)/antibiotic combination d...

2006-01-01

351

Petroleum hydrocarbons and organic chemicals in ground water -- prevention, detection and restoration: Proceedings. Ground water management: Book 17

Odor purification by bio-function; Seibutsu kino niyoru akushujoka

The 1993 Petroleum Hydrocarbons Conference was comprised of 3 days of technical presentations within the following topic areas: pollution prevention and cost control; development of remediation levels; free-phase and dissolved hydrocarbon contamination management; investigation and analysis of petroleum hydrocarbons; applications of computer modeling for remediation; design and implementation of bioventing; design and implementation of air sparging; soil vapor extraction as a remediation technique; and ground water remediation using natural bacteria. In addition, more than 100 leading companies in the ground water and petroleum industries participated in the Conference Exposition in which a variety of equipment and services for preventing, detecting and remediating ground water contaminated by petroleum hydrocarbons and other organic chemicals was showcased. Individual papers have been processed separately for inclusion in the appropriate data bases.

1993-11-10

352

Microbiological quality and biophenol content of hot air-dried Thassos cv. table olives upon storage

Odor purification process using bio-function, which is technologically called bio-deodorizing process, utilizes the function of microorganism to convert mal-odor substances to non-odor substances. It attracts attention because the operation cost of a facility is low due to non-use of chemicals and energy, and because it is environmentally friendly without the possibility of generating secondary pollution. It is being used in deodorizing at sewage treatment facilities, fertilizer plants, coating plants, and foundries in Japan, and is more widely used in Europe. The conventional deodorizing technology in Japan mostly focuses on processes of physical chemistry such as activated carbon treatment, chemical scrubbing, combustion, and masking, but bio-deodorizing process tends to replace the conventional processes. This paper explains (1) relation of mal-odor and microorganism, (2) bio-deodorizing system (solid phase system and liquid phase system), (3) points and precaution on using ...

1999-11-30

353

British Library Electronic Table of Contents (United Kingdom)

Abstract Microbiological quality and biophenol content evolution was studied in minimally processed Thassos cv table olives by hot air dehydration under mild conditions (40C, 24-h, aw-=-0.893) and storage under characteristic packaging conditions (vacuum, 100% N2 and air) at 4 and 20C over a period of 180 days. No salt was used in the production line or packaging. The undesirable microorganisms (Enterobacteriaceae, Staphylococcus aureus, Bacillus, Clostridium) were undetectable until the end of the storage period. Also, modified atmospheres prevented fungal growth at both temperatures apart from the samples stored in air, in which Penicillium and Aspergillus spp. were identified. At 20C, a coexistence of mesophilic bacteria and yeasts occurred. At 4C, yeasts were the predominant microflora...

2011-01-01

354

Laboratory tests of sludge-control additives

IL-1b enhances the antibacterial activity of astrocytes by activation of NF-kB

Laboratory {open_quotes}jar{close_quotes} tests compared eleven different fuel oil and diesel fuel sludge-control additives. Factors studied included (1) ability to disperse and prevent buildup of sludge deposits on surfaces, (2) ability to protect steel from corrosion, (3) ability to inhibit growth and proliferation of bacteria, and (4) ability to disperse water. Results varied greatly, and it was found that many commercial products do not do what they claim. It is concluded that fuel retailers should not believe manufacturers` claims for their additive products, but rather should test such products themselves to be sure that the benefits of treatment are real. A simplified form of the procedure used here is proposed as one way for dealers to do such testing.

1996-07-01

355

British Library Electronic Table of Contents (United Kingdom)

Astrocytes have important immune functions in CNS, and astrocytes stimulated by interferon-g were showed to have direct antimicrobial function. However whether astrocytes without the stimulation of cytokines have antibacterial function, and how this function is regulated are still largely unknown. In this study, we found that primary cultured astrocytes inhibited the growth of both gram-negative and gram-positive bacteria. Further more, we showed that interleukin-1b (IL-1b) enhanced the antibacterial effect in a dose-dependent manner, and the antibacterial effect of astrocytes from IL-1b receptor-deficient mice failed to be enhanced by IL-1b. IL-1b stimulated IkBa degradation, NF-kB nuclear translocation, and transactivation in astrocytes. NF-kB inhibitors blocked NF-kB activation and the ...

2010-01-01

356

Growth Inhibition and Induction of Stress Protein, GroEL, of Bacillus cereus Exposed to Antibacterial Peptide Isolated from Bacillus subtilis SC-8

British Library Electronic Table of Contents (United Kingdom)

This study was conducted to investigate the antibacterial effect of BSAP-254 on Bacillus cereus with the induced stress proteins. The BSAP-254 is an antimicrobial peptide isolated from soybean-fermenting bacteria, Bacillus subtilis SC-8. It had a narrow spectrum of activity against B. cereus group. The growth inhibitory effect of BSAP-254 (50??g/mL) reduced the population of B. cereus from >108 to 104 colony-forming units per milliliter within 30?min. In B. cereus exposed to BSAP-254, 14 intracellular proteins were differentially expressed as determined by 2-DE coupled with MS. Of the differentially expressed proteins identified, the stress protein GroEL, which is heat shock protein, was induced in B. cereus exposed to antibacterial peptide.

2011-01-01

357

Flavonols and an oxychromonol from Piliostigma reticulatum

British Library Electronic Table of Contents (United Kingdom)

The leaf extract from the plant Piliostigma reticulatum was found to exhibit antimicrobial activity against some bacteria and fungi such as Staphylococcus aureus (NCTC 6571), Escherichia coli (NCTC 10418), Bacillus subtilis (NCTC 8236), Proteus vulgaris (NCTC 4175), Aspergillus niger (ATCC 10578) and Candida albicans (ATCC 10231). Upon investigation of the chemical constituents present in the leaf extract, a total of seven compounds were isolated and their structures were unambiguously established by spectroscopic methods including HR-MS and NMR spectrometry. Four of the isolated compounds were novel, namely 6-C-methyl-2-p-hydroxyphenyloxychromonol (piliostigmol), 1, 6,8-di-C-methylquercetin-3,3prime,7-trimethyl ether, 2, 6,8-di-C-methylquercetin-3,3prime-dimethyl ether, 3 and 3prime,6,8,-...

2008-01-01

358

Enhanced inactivation of bacteria by metal-oxide nanoparticles combined with visible light irradiation

British Library Electronic Table of Contents (United Kingdom)

AbstractBackground In recent years nano-metaloxides which easily penetrate into the cells with special interest due to their higher chemical reactivity as compared to that of similar materials in the bulk form. Of particular interest are nano-TiO2 and ZnO, which have been widely used for their bactericidal and anticancerous properties. Purpose The aim of the present study was to examine the bactericidal properties of nano-TiO2 and ZnO combined with visible light on S. aureus and S. epidermitis, known for their high prevalence in infected wounds. Study Using the technique of electron-spin resonance (ESR) coupled with spin trapping, we examined the ability of TiO2 and ZnO nanoparticle suspensions in water to produce reactive oxygen species (ROS) with and without visible light irradiation. Th...

2011-01-01

359

Electrochromic effects of charge separation in bacterial photosynthesis: theoretical models

Effects of fungicides on endophytic fungi and photosynthesis in seedlings of a tropical tree, guarea guidonia (meliaceae)

The primary charge separation in photosynthetic bacteria generates a dimeric bacteriochlorophyll (BChl) cation and a bacteriopheophytin (BPheo) anion which lie within close proximity of each other (approx. 10 A). The two radicals also lie within van der Waals contact on opposite sides of a lone BChl bridging molecule. Spectral changes in the red (Q/sub y/) band of the bridge BChls have been observed on picosecond time scales following excitation of the reaction center (RC) and have been variously attributed to the formation of a BChl anion, to a charge-transfer state, or to electrochromic effects. They present calculations here which suggest that electrochromic effects caused by the photogenerated cation and/or anion can rationalize the optical changes observed in the flash photolyses as well as in trapping experiments.

1987-07-22

360

Effective Population Size Is Positively Correlated with Levels of Adaptive Divergence among Annual Sunflowers

Endophytes are microorganisms that live within healthy plant tissues, and include fungi and bacteria. They can be mutualists, comensals or even latent pathogens. Presence of these endosymbionts may affect host physiology, for example by consuming products of photosynthesis (endophytes are heterotrophs) or producing toxic metabolites. In this work two fungicides were used to eliminate fungal endophytes from seedlings of guarea guidonia. light saturated photosynthesis (Amax) was measured in endophytefree plants and compared with control plants. Each fungicide killed different fungal endosymbionts. phomopsis was more susceptible to benomyl while colletotrichum was more susceptible to propiconazole. Although suggestive, values of Amax were not significantly different for each treatment compared with control plants. No prediction can be made at this point about the final outcome of a given plantendophytic fungi interaction

2005-12-01

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361

British Library Electronic Table of Contents (United Kingdom)

The role of adaptation in the divergence of lineages has long been a central question in evolutionary biology, and as multilocus sequence data sets have become available for a wide range of taxa, empirical estimates of levels of adaptive molecular evolution are increasingly common. Estimates vary widely among taxa, with high levels of adaptive evolution in Drosophila, bacteria, and viruses but very little evidence of widespread adaptive evolution in hominids. Although estimates in plants are more limited, some recent work has suggested that rates of adaptive evolution in a range of plant taxa are surprisingly low and that there is little association between adaptive evolution and effective population size in contrast to patterns seen in other taxa. Here, we analyze data from 35 loci for si...

2011-01-01

362

Effect of induction of SOS response on expression of pBR322 genes and on plasmid copy number

Eating the enemy in Crohn's disease

Several lines of evidence are presented that indicate that the level of tetracycline resistance of Esherichia coli strains harboring plasmid pBR322 varies according to whether the SOS system of the host bacteria has been induced. These include use of strains in which the SOS system is expressed constitutively (lexA def.), is thermoinducible (recA441) or noninducible (lexA ind-), or is highly repressed (multiple copies of lexA+). Similar induction was observed with the product of another plasmid gene, beta-lactamase. The amounts of extractable plasmid DNA were also increased by SOS induction, and we propose that the SOS-induced increases in levels of tetracycline resistance and beta-lactamase activity are due to an increased plasmid copy number.

1989-09-01

363

British Library Electronic Table of Contents (United Kingdom)

Several old and new observations suggest the existence in Crohn's disease of a phagocytic disorder of macrophages related to impaired bactericidal activity of host cells or to the presence of invasive bacteria that have developed strategies to counteract macrophage killing. It was recently reported that disordered macrophage cytokine secretion underlies impaired acute inflammation and bacterial clearance in Crohn's disease. Secretion of proinflammatory cytokines by CD macrophages was impaired in response to E. coli or specific Toll-like receptor agonists. In addition, major advances in the etiology of Crohn's disease came from the existence of polymorphism in NOD2 and autophagy-related susceptibility genes (ATG16L1 and IRGM) in patients and from the identification of the presence of adhere...

2010-01-01

364

Distinctive Responses of Metabolically Active Microbiota to Acidification in a Thermophilic Anaerobic Digester

British Library Electronic Table of Contents (United Kingdom)

Acidification is one of the most common and serious problems inducing process failure in anaerobic digesters. The production of volatile fatty acids (VFAs) mainly triggers acidic shock. However, little is known about the bacteria involved in the processes of acidogenic metabolism, such as fermentation and reductive acetogenesis. Here, the metabolic responses of a methanogenic community to the acidification and resulting process deterioration were investigated using transcriptional profiling of both the 16S rRNA and formyltetrahydrofolate synthetase (FTHFS) genes. The 16S rRNA-based analyses demonstrated that the dynamic shift of bacterial populations was closely correlated with reactor performance, especially with VFA accumulation levels. The pH drop accompanied by an increase in VFAs stim...

2011-01-01

365

Detection of irradiated chicken by ESR spectroscopy of bone

Detection of Free-Living Amoebae in Some Water Sources and its Control by Ultraviolet- Radiation

Ionizing radiation has been used to treat poultry to remove harmful microorganisms, mainly Salmonella, which contaminates chicken, goose and other fresh and frozen poultry. This microorganism is sensitive to low dose radiation. Thus, irradiating these foods with doses between 1 to 7 kGy results in a large reduction of bacteria. Since it is necessary to determine whether irradiation has occurred and to what extend, this work studied the signal produced by ionizing radiation within the hard crystalline matrix of chicken`s bone to establish a control method. Chicken`s drumsticks were irradiated and bones separated from flesh were lyophilized and milled. ESR spectrum was then obtained. The ESR signal increased linearly with dose over the range 0.25 to 8.0 kGy. Free radicals evaluated during 30 days after irradiation showed stable in this period. (Author).

1995-10-01

366

Complete genome sequences of Brucella melitensis strains M28 and M5-90, with different virulence backgrounds.

Among the numerous free-living amoebae (FLA) of soil and water habitats, certain species belonging to two genera Acanthamoeba and Naegleria are facultative parasites of man.They cause disease called primary amoebic meningoencephalitis where history of contact with water was recorded in most of the cases especially with Naegleria species. The present work aimed to search for presence of free-living amoebae in the water and trials for its control by Ultraviolet-radiation (UV-radiation). Samples from different water sources were examined for the presence of free-living amoebae. These samples were cultured on non-nutrient agar streaked with bacteria. Amoebae were detected and identified by means of their morphological characters. Twelve positive cases of one hundred and twenty examined samples could be detected. The positive samples were exposed to different doses of UV-radiation for different times.

367

Competitive adsorption of binary mixture of Leptospirillum ferriphilum and Acidithiobacillus caldus onto pyrite

Brucella melitensis is a Gram-negative coccobacillus bacteria belonging to the Alphaproteobacteria subclass. It is an important zoonotic pathogen that causes brucellosis, a disease affecting sheep, cattle, and sometimes humans. The B. melitensis strain M5-90, a live attenuated vaccine cultured from the B. melitensis virulent strain M28, has been an effective tool to control brucellosis in goats and sheep in China. Here we report the complete genome sequences of B. melitensis M28 and M5-90, strains with different virulence backgrounds, which will serve as a valuable reference for future studies. PMID:21478357

2011-04-08

368

British Library Electronic Table of Contents (United Kingdom)

Leptospirillum ferriphilum and Acidithiobacillus caldus are two important acidophilic microorganisms involved in iron and sulfur oxidation during bioleaching. Cell adsorption to mineral surfaces is important for the direct leaching or contact leaching of minerals. In this study, we report the competitive adsorption of binary mixtures of L. ferriphilum LF-104 and A. caldus MTH-04 onto pyrite surfaces. The Langmuir adsorption parameter (CAm) indicated that these two bacteria underwent competitive adsorption to pyrite. Real-time quantitive PCR was used to quantify the relative amounts of L. ferriphilum and A. caldus adsorbed onto the surfaces of pyrite following exposure to a mixture of these two organisms. The adsorption of L. ferriphilum was not affected by A. caldus. However, adsorption of...

2010-01-01

369

Clostridiaceae and Enterobacteriaceae as active fermenters in earthworm gut content

British Library Electronic Table of Contents (United Kingdom)

The earthworm gut provides ideal in situ conditions for ingested heterotrophic soil bacteria capable of anaerobiosis. High amounts of mucus- and plant-derived saccharides such as glucose are abundant in the earthworm alimentary canal, and high concentrations of molecular hydrogen (H2) and organic acids in the alimentary canal are indicative of ongoing fermentations. Thus, the central objective of this study was to resolve potential links between fermentations and active fermenters in gut content of the anecic earthworm Lumbricus terrestris by 16S ribosomal RNA (rRNA)-based stable isotope probing, with [13C]glucose as a model substrate. Glucose consumption in anoxic gut content microcosms was rapid and yielded soluble organic compounds (acetate, butyrate, formate, lactate, propionate, succi...

2011-01-01

370

Chemical and microbial properties of mahyaveh, a traditional Iranian fish sauce

British Library Electronic Table of Contents (United Kingdom)

To the best of our knowledge, this is the first report on the chemical and microbial properties of traditional Iranian fish sauce, mahyaveh. Fish sauce samples used in this study originated from five different locations in the Southern part of Iran. The pH of mahyaveh samples from different locations was in the range of 4.89-7.55 and NaCl concentration was in the range of 7.48-17.1%. The overall mean of TVB-N in all the samples tested was 3098 mg/kg. Histamine, with the overall mean of 2662 mg/kg, was found to be the main biogenic amine in the Iranian fish sauce. The high histamine content can be related to the high levels of bacterial count especially enterobacteriaceae (overall mean of 3.41 log cfu/g) and lactic acid bacteria (overall mean of 4.13 log cfu/g) in this product. Spermidine w...

2012-01-01

371

Biological treatment of wine of distilleries

Bacterial adhesion reduction on a biocompatible Si^+ ion implanted austenitic stainless steel

The potential of the yeast Candida tropicalis and Candida guillermondii was evaluated and an isolated partnership of microorganisms of waters of the Medellin River, conformed by two bacteria and one leavening, to degrade the content of organic matter present in wine produced by the factory of Licores and Alcoholes de Antioquia (FLA) in aerobic process with biomass production. For each one of the microorganisms in study this capacity of removal in units of chemical demand of oxygen was quantified (CDO); in addition, parameters were analyzed such as yield of the biomass in relation to the removed CDO and to total reducing sugars (TRS) consumed, time of fermentation and speed of growth different dilutions from wine. Also the possible inhibition was analyzed that the present phenolic compounds in this wine can cause in the biological process of degradation.

372

British Library Electronic Table of Contents (United Kingdom)

The colonization of an implant surface by bacteria is an extremely important medical problem, which often leads to the failure of medical devices. Modern surface modification techniques, such as ion implantation, can confer to the surfaces very different properties from those of the bulk underlying material. In this work, austenitic stainless steel 316 LVM has been superficially modified by Si^+ ion implantation. The effect of surface modification on the biocompatibility and bacterial adhesion to 316 LVM stainless steel has been investigated. To this aim, human mesenchymal stem cells (hMSCs), as precursor of osteoblastic cells, and bacterial strains relevant in infections related to orthopedic implants, i.e., Staphylococcus aureus and Staphylococcus epidermidis, have been assayed. For the ...

2011-01-01

373

Assessing the effect of an antimicrobial wound dressing on biofilms

British Library Electronic Table of Contents (United Kingdom)

ABSTRACT To date the effect of silver-containing wound dressings on biofilms, known to be present in chronic wounds, has not been determined or documented. In this current study, we aimed to determine the antimicrobial effect of a silver-containing dressing on biofilms grown in a chambered slide model. Before the addition of a wound dressing onto a 24-hour biofilm, composed of either Pseudomonas aeruginosa, Enterobacter cloacae, Staphylococcus aureus, or a mixed bacterial community, a fluorescent dye was applied. This enabled the viability of sessile bacteria to be monitored in real-time, using a rapid form of confocal laser scanning microscopy over a contact time period of 48 hours. By analyzing all the three-dimensional data generated from the confocal time-lapse sequences, 90% of all se...

2008-01-01

374

Assessing Ground Water Development Potential Using Landsat Imagery

British Library Electronic Table of Contents (United Kingdom)

Seven villages in southeastern Kenya surround Mt. Kasigau and depend on the mountain's cloud forest for their water supply. Five of these villages have regularly experienced water shortages, and all village water supplies were contaminated with Escherichia coli bacteria. There is a need to economically find new sources of fresh ground water. Remote sensing offers a relatively quick and cost-effective way of identifying areas with high potential for ground water development. This study used spectral properties of features on Landsat remote sensing imagery to map linear features, soil types, surface moisture, and vegetation. Linear features represented geologic or geomorphologic features indicating either shallow ground water or areas of increased subsurface hydraulic conductivity. Regarding...

2010-01-01

375

Anti-Infection Dip Suggestions for the Coloplast Titan Inflatable Penile Prosthesis in the Era of the Infection Retardant Coated Implant

British Library Electronic Table of Contents (United Kingdom)

Abstract Introduction.- Infection is the worst complication seen with inflatable penile prosthesis (IPP). Both the American Medical Systems (AMS) and Coloplast IPP have infection retardant coatings. AMS is coated at the factory with rifampicin and minocycline (InhibiZone). The Coloplast IPP has a hydrophilic coating covalently bonded to its components that will absorb any aqueous solution before implantation and provides increased surface lubricity to decrease bacterial adherence. Aim.- We tested several antibiotic dips comparing zones of inhibition (ZOI) against five commonly infecting bacteria with coated Coloplast implants. Results were compared with those ZOI created with strips of an AMS IPP precoated with InhibiZone. Methods.- Pieces of sterile Coloplast Titan IPP were dipped in (i) ...

2011-01-01

376

An Outbreak of Post-Cataract Surgery Endophthalmitis Caused by Pseudomonas aeruginosa

British Library Electronic Table of Contents (United Kingdom)

Objective Infectious endophthalmitis is among the most serious complications of cataract surgery. Gram-negative bacteria, including Pseudomonas aeruginosa, are responsible for less than 30% of cases; however, their rapidity of infection and virulence often results in poor visual outcome despite prompt antibiotic treatment. The purpose of this study was to investigate an outbreak of post-cataract surgery P. aeruginosa endophthalmitis in India. Design Hospital-based case series. Participants Twenty patients with acute postoperative endophthalmitis who underwent cataract surgery at one of the peripheral centers of Joseph Eye Hospital, Tiruchirapalli, Tamil Nadu, India, from February 23 to April 2, 2008. Interventions Vitreous aspirates and environmental surveillance specimens were inoculated ...

2009-01-01

377

Acid mine water treatment in wetlands: an overview of an emergent technology

Ability of a ?minimum?? microbial food web model to reproduce response patterns observed in mesocosms manipulated with N and P, glucose, and Si

Experimental wetlands are being constructed on mined lands in the United States as an inexpensive alternative to conventional acid mine water treatment facilities. The US Bureau of Mines is conducting an inventory of these constructed wetlands as part of a long-term evaluative study. Preliminary results, based on the 20 sites surveyed to date, indicate that the wetlands dominated by emergent species are out-performing the Sphagnum-dominated wetlands, and that much of the water treatment is accomplished by other aspects of the wetland, including bacteria, algae, amendments and other plants. Iron concentrations as high as 85 mg/l are reduced to less than 3 mg/l after flow through the constructed wetlands. Manganese is also removed, though somewhat less efficiently. 12 refs., 1 fig., 1 tab.

1987-12-31

378

British Library Electronic Table of Contents (United Kingdom)

We compared an idealised mathematical model of the lower part of the pelagic food web to experimental data from a mesocosm experiment in which the supplies of mineral nutrients (nitrogen and phosphorous), bioavailable dissolved organic carbon (BDOC, as glucose), and silicate were manipulated. The central hypothesis of the experiment was that bacterial consumption of BDOC depends on whether the growth rate of heterotrophic bacteria is limited by organic-C or by mineral nutrients. In previous work, this hypothesis was examined qualitatively using a conceptual food web model. Here we explore the extent to which a ?simplest possible?? mathematical version of this conceptual model can reproduce the observed dynamics. The model combines algal?bacterial competition for mineral nutrients (phosphor...

2007-01-01

379

Radiation-induced mutations at mouse hemoglobin loci

Phosphomimetic mutation of the mitotically phosphorylated serine 1880 compromises the interaction of the transmembrane nucleoporin gp210 with the nuclear pore complex

In experiments designed to detect new mutations affecting hemoglobin, we irradiated the male or female parent in reciprocal crosses of two mouse strains that differ in alleles at the hemoglobin (Hba, Hbb) loci as well as at five other specific loci. Offspring were analyzed for hemoglobin properties (electrophoretic pattern, solubility, crystal pattern), serum albumin differences, erythrocyte lysis, reticulocyte count, and external appearance. Five hemoglobin variants were found among the mutants. In three, the genetic contribution from the irradiated father was not expressed with regard to the #alpha#-chain; one carried a tandem duplication (the first known case in the mouse) involving Hbb; and one probably resulted from double nondisjunction of chromosome 7. The finding that major chromosome aberratios can mimic hemoglobin mutations indicates the need, in similar experiments, to follow F_1 screening with thorough cytogenetic analysis. The variants in which there ...

380

Negative regulation of {beta}-catenin/Tcf signaling by naringenin in AGS gastric cancer cell

The nuclear pore complexes (NPCs) reversibly disassemble and reassemble during mitosis. Disassembly of the NPC is accompanied by phosphorylation of many nucleoporins although the function of this is not clear. It was previously shown that in the transmembrane nucleoporin gp210 a single serine residue at position 1880 is specifically phosphorylated during mitosis. Using amino acid substitution combined with live cell imaging, time-lapse microscopy and FRAP, we investigated the role of serine 1880 in binding of gp210 to the NPC in vivo. An alanine substitution mutant (S1880A) was significantly more dynamic at the NPC compared to the wild-type protein, suggesting that serine 1880 is important for binding of gp210 to the NPC. Moreover a glutamate substitution (S1880E) closely mimicking phosphorylated serine specifically interfered with incorporation of gp210 into the NPC and compromised its post-mitotic recruitment to the nuclear envelope of daughter nuclei. Our ...

2007-07-15

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381

Microaerophilic growth and induction of the photosynthetic reaction center in Rhodopseudomonas viridis

Functional activation of {beta}-catenin/Tcf signaling plays an important role in early events in carcinogenesis. We examined the effect of naringenin against {beta}-catenin/Tcf signaling in gastric cancer cells. Reporter gene assay showed that naringenin inhibited {beta}-catenin/Tcf signaling efficiently. In addition, the inhibition of {beta}-catenin/Tcf signaling by naringenin in HEK293 cells transiently transfected with constitutively mutant {beta}-catenin gene, whose product is not phosphorylated by GSK3{beta}, indicates that its inhibitory mechanism was related to {beta}-catenin itself or downstream components. To investigate the precise inhibitory mechanism, we performed immunofluorescence, Western blot, and EMSA. As a result, our data revealed that the {beta}-catenin distribution and the levels of nuclear {beta}-catenin and Tcf-4 proteins were unchanged after naringenin treatment. Moreover, the binding activities of Tcf complexes to consensus DNA were not ...

2005-09-30

382

Maintenance and regulation of extracellular volume and the ion environment in Drosophila larval nerves.

Rhodopseudomonas viridis was grown in liquid culture at 30 degrees C anaerobically in light (generation time, 13 h) and under microaerophilic growth conditions in the dark (generation time, 24 h). The bacterium could be cloned at the same temperature anaerobically in light (1 week) and aerobically in the dark (3 to 4 weeks) if oxygen was limited to 0.1%. Oxygen could not be replaced by dimethyl sulfoxide, potassium nitrate, or sodium nitrite as a terminal electron acceptor. No growth was observed anaerobically in darkness or in the light when air was present. A variety of additional carbon sources were used to supplement the standard succinate medium, but enhanced stationary-phase cell density was observed only with glucose. Conditions for induction of the photosynthetic reaction center upon the change from microaerophilic to phototrophic growth conditions were investigated and optimized for a mutant functionally defective in phototrophic growth. R. viridis ...

1989-05-01

383

Identification of the binding domain for NADP"+ of human glucose-6-phosphate dehydrogenase by sequence analysis of mutants

In mammals and insects, paracellular blood barriers isolate the nervous system from the rest of the animal. Glia and accessory cells of the nervous system use pumps, channels, cotransporters, and exchangers collectively to maintain the extracellular ion environment and osmotic balance in the nervous system. At present, the molecular mechanisms that regulate this process remain unclear. In humans, loss of extracellular ion and volume regulation in the nervous system poses serious health threats. Drosophila is a model genetic organism with a proven track record for uncovering molecular mechanisms relevant to human health and disease. Here, we review what is known about extracellular ion and volume regulation in larval abdominal nerves, present some new data about the impact of neural activity on the extracellular environment, and relate the findings to mammalian systems. Homologies have been found at the level of morphology, physiology, molecular mechanisms, and ...

2011-02-08

384

Identification of protein phosphorylation sites within Ser/Thr-rich cluster domains using site-directed mutagenesis and hybrid linear quadrupole ion trap Fourier transform ion cyclotron resonance mass spectrometry

Human erythrocyte glucose-6-phosphate is normally quite stable in the presence of 10 #mu#M NADP"+. Certain glucose-6-phosphate dehydrogenase variants lose virtually all their activity at this concentration of NADP"+ but are reactivated by 200 #mu#M NADP"+. Such variants presumably have a defect in their NADP"+-binding site. The authors analyzed the sequence of cDNA or genomic DNA from seven unrelated patients with hemolytic anemia due to the inheritance of variants that are reactivated by NADP"+. Six patients had substitutions of one of three adjacent amino acids, and the seventh patient had another amino acid substitution 23 residues downstream. These amino acids are highly conserved, all being present in rat and all but one being found also in Drosophila. The anomalous electrophoretic behavior of some of the variants can be explained by their loss of ability to bind NADP"+. The conclude that the region in which these mutations occur defines the binding domain for NADP"+ and that ...

385

British Library Electronic Table of Contents (United Kingdom)

We describe a method for the analysis of multi-site phosphorylation in serine/threonine (Ser/Thr)-rich protein sequences. Site-specific mutagenesis was used to introduce tryptic cleavage sites in the serine glutamine/threonine glutamine cluster domain (SCD) of the human checkpoint protein kinase (Chk2). The mutant proteins were shown to autophosphorylate on residues that are inducibly phosphorylated when mammalian cells are exposed to ionizing radiation (serine 33/35, serine 516, threonine 68 and threonine 432). Five Ser/Thr clusters within the SCD were flanked by arginine or lysine residues to produce tryptic peptides for nanospray liquid chromatography (nanoLC)/linear quadrupole ion trap Fourier transform ion cyclotron resonance mass spectrometry. Phosphorylation sites were assigned usin...

2007-01-01

386

Host derived inflammatory phospholipids regulate rahU (PA0122) Gene, Protein, and Biofilm Formation in Pseudomonas aeruginosa

British Library Electronic Table of Contents (United Kingdom)

This study describes the role of "inflammatory" oxidized (Ox) phospholipids in regulation of rahU (PA0122) expression and biofilm formation in Pseudomonas aeruginosa (383) wild type (rahU+) and rahU mutant (rahU-) strains. Functional analysis of RahU protein from P. aeruginosa in presence of Ox-phospholipids show: (a) LysoPC modulates RahU gene/and protein expression in rahU+ cells; (b) rahU promoter activity is increased by lysoPC and inhibited by PAPC, Ox-PAPC and arachidonic acid; the latter inhibitory effect can be reversed by lysoPC, which was enzymatically derived from PAPC; (c) biofilm formation increased in rahU- cells as compared to rahU+; and (d) inhibition of rahU promoter activity by PAPC and AA (but not lysoPC) showed significantly augmented biofilm formation in rahU+ but not ...

2011-01-01

387

High-flux isobutanol production using engineered Escherichia coli: a bioreactor study with in situ product removal

British Library Electronic Table of Contents (United Kingdom)

Promising approaches to produce higher alcohols, e.g., isobutanol, using Escherichia coli have been developed with successful results. Here, we translated the isobutanol process from shake flasks to a 1-L bioreactor in order to characterize three E. coli strains. With in situ isobutanol removal from the bioreactor using gas stripping, the engineered E. coli strain (JCL260) produced more than 50?g/L in 72?h. In addition, the isobutanol production by the parental strain (JCL16) and the high isobutanol-tolerant mutant (SA481) were compared with JCL260. Interestingly, we found that the isobutanol-tolerant strain in fact produced worse than either JCL16 or JCL260. This result suggests that in situ product removal can properly overcome isobutanol toxicity in E. coli cultures. The isobutanol prod...

2011-01-01

388

Genetical approach to oxygen toxicity. [Saccharomyces cerevisiae

Functional expression of anti-hepatitis B virus (HBV) preS2 antigen scFv by cspA promoter system in Escherichia coli and application as a recognition molecule for single-walled carbon nanotube (SWNT) field effect transistor (FET)

The role of intermediate products of dioxygen reduction in cytotoxic effects ascribed to oxygen molecules was studied in vivo using various yeast mutants with changed response to oxygen stress. It has been documented that superoxide radical exerts its deleterious effects on yeast cells directly and the role of other oxygen species derived from it is hardly detectable. Yeast Saccharomyces cerevisiae, however, cannot be considered as a typical eukaryotic organism due to its inability of synthesizing polyunsaturated fatty acids (pufa). These fatty acids are known as main target molecules during oxidative stress and their peroxidation leads to cytotoxic effects. As fatty acid content could be easily manipulated in yeast, this organism was used to evaluate the contribution of pufa peroxidation process to the cytotoxic effects of oxygen. Results obtained show, that yeast cells containing linolenic acid as the main constituent of phospholipids are hypersensitive to oxygen ...

1986-01-01

389

British Library Electronic Table of Contents (United Kingdom)

The preS2 antigens of hepatitis B virus (HBV), which causes a serious health problem in the world, have been implicated in hepatocyte cell binding and viral penetration. Therefore, the importance of antibody production against preS2 antigen for early diagnosis of HBV has been well established. In this study, the recombinant HBV preS2 single chain variable fragment (scFv) antibody was successfully expressed in E. coli with the novel cold shock vector (pCold) under the cspA promoter, and its expression level was compared with the pET vector under the T7 promoter. Additionally, a host with an oxidizing cytoplasm, E. coli trxB/gor double mutant, was used to improve the soluble expression. The anti-HBV preS2 scFv using pCold vector was successfully expressed in a soluble and functional form in ...

2010-01-01

390

Final report of the specific research. Investigations on the analysis of bio-protective factors against radiation. 1998-2000 FY (Research Group of NIRS)

Extracts of the marine brown macroalga, Ascophyllum nodosum, induce jasmonic acid dependent systemic resistance in Arabidopsis thaliana against Pseudomonas syringae pv. tomato DC3000 and Sclerotinia sclerotiorum

This report concerns investigations in the title conducted by 8 groups of National Institute of Radiological Sciences (NIRS) during the period of 1998-2000. The groups are for investigation of: Effects of p53 tumor suppressor gene in radiation-induced leukemia, Role of atm-gene in dose rate effect of ionizing radiation, Function of DNA-dependent protein kinase catalytic subunit (DNA-PK{sub cs}), Functional complementation of radiation-sensitive mutant M10 cell line by human XRCC4 cDNA expression, Role of radiation-induced apoptosis in digital defects in embryonic mice, Functional analysis of S-phase specific novel nuclear protein NP95 by gene targeting, Role of chemokine in T cell development and lymphomagenesis, and establishment of production techniques of gene-modified mice using embryonic stem cells for genetic analysis of radiation-sensitive genes. The groups describe summaries of their studies and published original articles are also given. (N.I.)

2002-03-01

391

British Library Electronic Table of Contents (United Kingdom)

We studied the mechanism of Ascophyllum nodosum (a brown macroalga) induced resistance in Arabidopsis thaliana against Pseudomonas syringae pv. tomato DC3000. Root treatment of A. thaliana Col-0 plants with extracts of A. nodosum [aqueous (ANE), chloroform (C-ANE) and ethylacetate fractions, (E-ANE)] reduced the development of disease symptoms on the leaves. These extracts also induced resistance in salicylic acid deficient NahG and ics1 plants. However, the extracts did not elicit an effect on jar1 (jasmonic acid resistance 1) mutant. A. nodosum extract induced resistance to Pst DC3000 correlated with increased expression of jasmonic acid related gene transcripts PDF1.2 while PR1 and ICS1 expression were less affected. Additionally, pretreatment of Arabidopsis plants with ANE, protected t...

2011-01-01

392

Comparative action spectrum for ultraviolet light killing of mouse melanocytes from different genetic coat color backgrounds

Boron-Dependent Degradation of NIP5;1 mRNA for Acclimation to Excess Boron Conditions in Arabidopsis.

The photobiology of mouse melanocyte lines with different pigment genotypes was studied by measuring colony-forming ability after irradiation. The cell lines were wild-type black (melan-a) and the mutants brown (melan-b) and albino (melan-c). Four lamps emitting various UV wavelengths were used. These were germicidal (UVC, 200-280 nm), 82.3% output at 254 nm, TL01 (UVB, 280-320 nm), 64.2% at 310-311 nm, FS20, broadband with peak output at 312 nm and Alisun-S (UVA, 320-400 nm), broadband with peak output at 350-354 nm. Appropriate filtration reduced the contaminating UVC to nonlethal levels for the longer waverange lamps. It is clear from these studies that, in pigment cells, monochromatic results cannot predict polychromatic responses and that cell death from solar irradiations is a complex phenomenon that depends on more than DNA damage. (author).

1997-01-01

393

Bacterial Pili exploit integrin machinery to promote immune activation and efficient blood-brain barrier penetration.

Boron (B) is an essential plant micronutrient that is toxic at higher levels. NIP5;1 is a boric acid channel required for B uptake and growth under B deficiency. Accumulation of the NIP5;1 transcript is upregulated under B deficiency in Arabidopsis thaliana roots. To elucidate the mechanism of regulation, the 5' untranslated region (UTR) of NIP5;1 was tested for its ability to confer B-dependent regulation using ?-glucuronidase and green fluorescent protein as reporters. This analysis showed that the 5' UTR was involved in NIP5;1 transcript accumulation in response to B conditions. We also found that high-B conditions trigger NIP5;1 mRNA degradation and that the sequence from +182 to +200 bp in the 5' UTR is required for this mRNA destabilization. In the nip5;1-1 mutant background, a NIP5;1 complementation construct without the 5' UTR produced high levels of mRNA accumulation, increased B concentrations in tissues, and reduced growth under high-B conditions. These ...

2011-09-01

394

Absence of linkage of apparently single gene mediated ADHD with the human syntenic region of the mouse mutant coloboma

Group B Streptococcus (GBS) is the leading cause of meningitis in newborn infants. Bacterial cell surface appendages, known as pili, have been recently described in streptococcal pathogens, including GBS. The pilus tip adhesin, PilA, contributes to GBS adherence to blood-brain barrier (BBB) endothelium; however, the host receptor and the contribution of PilA in central nervous system (CNS) disease pathogenesis are unknown. Here we show that PilA binds collagen, which promotes GBS interaction with the ?(2)?(1) integrin resulting in activation of host chemokine expression and neutrophil recruitment during infection. Mice infected with the PilA-deficient mutant exhibit delayed mortality, a decrease in neutrophil infiltration and bacterial CNS dissemination. We find that PilA-mediated virulence is dependent on neutrophil influx as neutrophil depletion results in a decrease in BBB permeability and GBS-BBB penetration. Our results suggest that the bacterial pilus, ...

2011-09-06

395

A single amino acid substitution results in a retinoblastoma protein defective in phosphorylation and oncoprotein binding

Attention deficit disorder (ADHD) is a complex biobehavioral phenotype which affects up to 8% of the general population and often impairs social, academic, and job performance. Its origins are heterogeneous, but a significant genetic component is suggested by family and twin studies. The murine strain, coloboma, displays a spontaneously hyperactive phenotype that is responsive to dextroamphetamine and has been proposed as a genetic model for ADHD. Coloboma is a semi-dominant mutation that is caused by a hemizygous deletion of the SNAP-25 and other genes on mouse chromosome 2q. To test the possibility that the human homolog of the mouse coloboma gene(s) could be responsible for ADHD, we have carried out linkage studies with polymorphic markers in the region syntenic to coloboma (20p11-p12). Five families in which the pattern of inheritance of ADHD appears to be autosomal dominant were studied. Segregation analysis of the traits studied suggested that the best fitting model was a ...

1995-12-18

396

( sup 14 C)-Sucrose uptake by guard cell protoplasts of pisum sativum, argenteum mutant

The authors have previously identified a small-cell lung cancer cell line (NCI-H209) that expresses an aberrant, underphosphorylated form of the retinoblastoma protein RB1. Molecular analysis of RB1 mRNA from this cell line revealed a single point mutation within exon 21 that resulted in a nonconservative amino acid substitution (cysteine to phenylalanine) at codon 706. Stable expression of this mutant RB1 cDNA in a human cell line lacking endogenous RB1 demonstrated that this amino acid change was sufficient to inhibit phosphorylation. In addition, this cysteine-to-phenylalanine substitution also resulted in loss of RB1 binding to the simian virus 40 large tumor and adenovirus E1A transforming proteins. These results confirm the importance of exon 21 coding sequences and suggest that the cysteine residue at codon 706 may play a role in achieving a specific protein conformation essential for protein-protein interactions.

397

Regulation of the pT181 encoded tetracycline resistance gene in Straphylococcus aureus

Guard cells rely on import for their supply with reduced carbon. The authors tested by silicone oil centrifugation the ability of guard cell protoplasts to accumulated ({sup 14}C)-sucrose. Uptake rates were corrected after measurement of {sup 14}C-sorbitol and {sup 3}H{sub 2}O spaces. Sucrose uptake followed biphasic kinetics, with a high-affinity component below 1 mM external sucrose (apparent K{sub m} 0.8 mM at 25C) and a low-affinity nonsaturable component above. Uptake depended on pH (optimum at pH 5.0). Variations in the concentrations of external KCl, CCCP, and valinomycin indicated that about one-half of the sucrose uptake rate could be related to an electrochemical gradient across the plasmalemma. Total uptake rates measured at 5 mM external sucrose seem to be sufficient to replenish emptied plastids with starch within a few hours.

1991-05-01

398

The role of nitrogen fixation in intensive forestry in Canada. Part 1

pT181 is a naturally-occurring 4437 basepair (bp) plasmid isolated from Staphylococcus aureus which encodes inducible resistance to tetracycline (Tc). The DNA sequence data has identified three open reading frames (ORFs). The largest ORF B, has been found to be responsible for the Tc resistance phenotype of pT181. Since most Tc resistance systems appear to be regulated by an effector protein and a repressor protein, several Bal 31 deletion mutants of pT181 were constructed and analyzed in an effort to identify the elements involved in Tc resistance. Two transcomplementing groups of mutants were identified within the tet gene. The mechanism of Tc resistance was studied by assaying the accumulation of (7-/sup 3/H) Tc by Tc sensitive cells, and uninduced and induced pT181-containing cells. A sharp decrease in accumulation of the drug after an initial increase was observed in Tc induced pT181-containing cells. In vivo labeling of Bacillus subtilis ...

1986-01-01

399

The association of asymptomatic bacterial vaginosis with upper genital tract infection.

Intensification of forest management and harvesting will lead to increased pressures on relatively infertile forest soils with possible reductions in levels of nitrogen and organic matter. It will be necessary for foresters to manage the soils, along with trees, if they wish to maintain site productivity. Nitrogen fixation should be considered as a supplementary or alternative soil amendment method. Free-living nitrogen-fixing bacteria appear to contribute minor amounts of combined nitrogen to forest soils, but it is possible that this contribution has been underestimated. The nitrogen-fixing symbioses of higher plants with bacteria contribute up to 300 kg year of nitrogen, more than sufficient to replace potential losses of nitrogen in intensive forestry. The nitrogen-fixing process, however, requires sufficient supplies of certain elements and is sensitive to environmental factors. There are numerous examples of nitogen-fixing symbioses ...

1984-01-01

400

Sudden infant death syndrome and placental disorders: the thyroid-selenium link.

Objective: To determine whether asymptomatic bacterial vaginosis (BV) is associated with upper genital tract inflammation or bacterial colonization.Methods: Fifty nonpregnant women with intact uteri who planned to undergo gynecologic surgery and had no recent symptoms of vaginal infection were enrolled. We obtained a vaginal swab for Gram stain, endocervical swab for chlamydia and gonorrhea DNA probe testing, and Pipelle endometrial biopsy for aerobic and anaerobic cultures and histology. We correlated surgical findings and histology of available surgical specimens with the microbiologic results. The diagnosis of BV was made according to Speigel's criteria. Bacteria isolated from the uterus were classified as high virulence versus low virulence. Contingency tables were analyzed using the chi-square or Fisher Exact tests.Results: Twenty-one of 50 patients had BV on Gram stain, 3 had intermediate BV, and 3 had unreadable slides. Eleven patients had histologic ...

1998-07-01

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401

Quality of water and time-of-travel in Bakers Creek near Clinton, Mississippi. [Bakers Creek

Placental insufficiency, inducing hypoxia-ischaemia, is considered a major cause of neuronal injury and impaired post natal development. Placental insufficiency alters the metabolism of arachidonic acid and its oxidation products. Premature labour and low-birth-weight infants are associated with reduced intrauterine blood-flow and infections of the reproductive tract. Thyroidal activity is depressed in undernutrition (placental insufficiency). Premature infants require extra vitamin C for normal tyrosine metabolism (tyrosine is the thyroxine precursor). Among the symptoms indicating infantile cretinism, which appear during 3-5 months of age are: delayed union of skull bones, torpid behaviour, slow feeding, cyanosis during feeding, excessive sleepiness, enlarged tongue, umbilical herniation, flabby musculature, short stature and delayed development. These symptoms have all been described in low-birth-weight infants and sudden infant death syndrome victims by various authors. ...

1997-04-01

402

Production of Shiga-like toxins by Escherichia coli O157:H7 can be influenced by the neuroendocrine hormone norepinephrine.

A short-term intensive quality-of-water study was conducted during a period of generally low streamflow in Bakers Creek and its tributary, Lindsey Creek, near Clinton, Mississippi. During the September 15-18, 1980 study, dissolved oxygen concentrations in Bakers Creek were less than 5 milligrams per liter. The specific conductance, 5-day biochemical oxygen demand, nutrient concentrations, and bacteria densities in Bakers Creek decreased downstream through the study reach. The mean specific conductance decreased from 670 to 306 microhms per centimeter. The 5-day biochemical oxygen demand decreased from 19 to 2.8 milligrams per liter. The mean total nitrogen and phosphorous concentrations decreased from 10 and 7.1 to 1.0 and 0.87 milligram per litter, respectively. The maximum fecal bacteria decreased from 7200 to 400 colonies per 100 milliliter. The concentrations of mercury, iron, and manganese in a sample collected at the downstream site ...

1982-01-01

403

Microbial oxidation of soluble sulfide in produced water from the Bakkeen Sands

To examine whether the neuroendocrine hormone norepinephrine may influence the production of the Shiga-like toxins (SLTs), several Escherichia coli O157:H7 clinical isolates were grown in the presence or absence of norepinephrine. An in vitro culture system consisting of low (<1500 colony-forming units/ml) initial concentrations of inocula into a serum-based medium was used to more closely approximate in vivo conditions. The growth of all isolates was increased several logs in the presence of norepinephrine, as compared with the growth in controls, during a 24-hour growth period. Controls included additional dextrose as well as the use of the norepinephrine metabolite normetanephrine, which contains one more methyl group than norepinephrine and hence would serve as a better energy source for growth if the effect were solely nutritionally mediated. During the 24 hours of growth, the production of cell-associated SLT-I on a protein-equivalent basis was shown to be increased over ...

1996-10-01

404

Manganite reduction by Shewanella putrefaciens MR-4

The presence of soluble sulfide in produced water results in problems for the petroleum industry due to its toxicity, odor, corrosive nature, and potential for wellbore plugging. Sulfide oxidation by indigenous nitrate-reducing bacteria (NRB) present in brine collected from wells at the Coleville Unit (CVU) in Saskatchewan, Canada, was investigated. Sulfide oxidation took place readily when nitrate and phosphate were added to brine enrichment cultures, resulting in a decrease in sulfide levels of 99-165 ppm to nondetectable levels (< 3.3 ppm). Produced water collected from a number of producing wells was screened to determine the time required for complete sulfide oxidation, in order to select candidate wells for treatment. Three wells were chosen, based on sulfide removal in 48 hours or less. These wells were treated down the backside of the annulus with a solution containing 10 mM KNO{sub 3} and 100 {mu}M NaH{sub 2}PO{sub 4}. Following a 24- to 72-hour ...

1995-12-31

405

Gamma irradiation in the control of pathogenic bacteria in refrigerated ground chicken meat; Irradiacao gama no controle de bacterias patogenicas em carne de frango refrigerada

Previous studies have documented dissimilatory growth of bacteria on solid Mn{sup 4+} oxide, but Mn{sup 3+} oxides have not been previously studied; here the authors have demonstrated for the first time the bacterial reduction of manganite. Strain MR-4 of Shewanella putrefaciens was able to grow on and rapidly reduce insoluble needle-shaped crystals of synthetic manganite (MnOOH), converting them to soluble Mn{sup 2+} in the process. The rate of Mn{sup 3+} reduction was optimal at pH of 7.0 and 26 C consistent with an enzymatic reaction. In addition the rates of reduction were in proportion to the amount of manganite added, but nearly independent of the cell concentration present (e.g., cell number had only a small effect on the rate of Mn{sup 3+} reduction at early stages of growth) suggesting that surface properties were dictating the rates of metal reduction. This thesis was supported by major differences in reduction rates when Mn oxides of different surface ...

1998-11-01

406

Development of food preservation and processing techniques by radiation

This work evaluated the effect of gamma radiation on reducing the population of Staphylococcus aureus, Escherichia coli nd Salmonella typhimurium in ground chicken breast stored under refrigeration. The experiment included a control and 4 doses of gamma radiation ( 2.0, 4.0, 6.0 and 8.0 kGy) along with 5 periods of storage under refrigeration ( 1, 7 14, 21 and 28 days). Samples of ground chicken breast were inoculated with Staphylococcus aureus (ATCC 14458), Escherichia coli (ATCC 11105) and Salmonella typhimurium (ATCC 0626), irradiated at temperatures between 4 and 8 deg C and stored under refrigeration (5 deg C) for 28 days. The increased radiation dose and period of storage under refrigeration caused a reduction of Staphylococcus aureus, Escherichia coli and Salmonella typhimurium populations in the ground chicken breast. Mean radiation D values determined for Staphylococcus aureus and Escherichia coli were 0.41 and 0.72 kGy, respectively. Gamma irradiation was an effective ...

2000-09-01

407

Biosorption of heavy metals under anaerobic conditions. Final report; Biosorption von Schwermetallen unter anaeroben Bedingungen. Abschlussbericht

Development of food preservation and processing techniques by radiation was performed. Gamma irradiation at 2-10 kGy is considered to be an effective method to control pathogenic bacteria in species including Escherichia coli O157:H7. Gamma irradiation at 5 kGy completely eliminated pathogenic bacteria in beef. Gamma irradiation at such doses and subsequent storage at less than 4 deg C could ensure hygienic quality and prolong the microbiological shelf-life resulting from the reduction of spoilage microorganisms. Gamma irradiation on pre-rigor beef shortens the aging-period, improves tenderness and enhances the beef quality. And, a new beef processing method using gamma irradiation, such as in the low salt sausage and hygienic beef patty was developed. Safety tests of gamma-irradiated meats(beefs: 0-5 kGy; porks: 0-30 kGy) in areas such as genotoxicity, acute toxicity, four-week oral toxicity, rat hepato carcinogenesis and the anti oxidative ...

1988-04-18

408

BIBRA "t"r"a"d"e"m"a"r"k - the biological treatment of radioactive waste water

The precipitation of heavy metals as hydroxides is the standard technique for the decontamination of waste water streams polluted by these elements. On the other side, progress in research has been made concerning the biosorption onto dead biomass and bioprecipitation supported by physiologically active bacteria. As the aim of this study, a flexible strategy has been envisaged cleaning a waste water with definite heavy metal load underlying the process mentioned above. Suitable bacteria were enriched and the process was tested in a technical plant. As result, a very high efficiency of heavy metal elimination has been found. The field of application covered by the acquired process is identical with the whole range of the waste water streams polluted by heavy metals. In addition, a second stage may be necessary if there are any further contaminants to be removed. (orig.) [Deutsch] Bei der Reinigung von schwermetallhaltigen Abwaessern ist der ...

1996-12-31

409

Anaerobic thermophilic bacteria isolated from a Venezuelan oil field and its potential use in microbial improved oil recovery

BIBRA "t"r"a"d"e"m"a"r"k, is the new bio-technological method developed in Gundremmingen for treating radioactive waste water, using bacteria in a process analogous to the long-established principle of communal sewage treatment plants. The method exploits the behaviour of the micro-organisms found there, to establish optimum adaptation of their population for decomposing the typical pollutants found in this washing water. This procedure is particularly suitable for nuclear engineering plants, because in such plants the waste water composition changes little so that the bacteria can achieve optimum adaptation to this waste water. The organic ingredients of the washing media are decomposed by introducing air. The advantage of the procedure is not only the significant reduction of the amount of waste material, but also enhanced efficiency of the cleaning process. The decontamination factor in Gundremmingen improved from a factor of 5 to a factor ...

1999-03-01

410

Hydration of swelling clay and bacteria interaction. An experimental in situ reaction study; Hydratation des argiles gonflantes et influence des bacteries. Etude experimentale de reaction in situ

The objective of this work is to determine the ability of indigenous bacteria from a Venezuelan oil field to grow under reservoir conditions inside a porous media, and to produce metabolites capable of recovering residual crude oil. For this purpose, samples of formation waters from a central-eastern Venezuelan oil reservoir were enriched with different carbon sources and a mineral basal media. Formation water was used as a source of trace metals. The enrichments obtained were incubated at reservoir temperature (71{degrees}C), reservoir pressure (1,200 psi), and under anaerobic conditions for both outside and inside porous media (Berea core). Growth and metabolic activity was followed outside porous media by measuring absorbance at 660 nm, increases in pressure, and decreases in pH. Inside porous media bacterial activity was determined by visual examination of the produced waters (gas bubbles and bacterial cells). All the carbohydrates tested outside porous media ...

1995-12-31

411

[Molecular cloning and expression of an isotoxin gene, alpha-bungarotoxin, from Bungarus multicinctus].

This study reports on the physical-chemical behaviour of swelling di-octahedral clays (smectites) and their interaction with aqueous solutions and bacteria (Shewanella putrefaciens). Experimental results are presented for compacted clays, hydrated under confined volume conditions, using a new type of reaction-cell (the 'wet-cell' of Warr and Hoffman, 2004) that was designed for in situ X-ray diffraction (XRD) measurement. For comparison, dispersed clay systems were studied using standard batch solutions subjected to varying degrees of agitation. The combination of time-dependent in situ XRD measurements with gravimetric measurements and calculated diffraction patterns using the CALCMIX software (Plancon and Drits, 1999) allowed to successful quantification of the dynamics of water uptake and storage. This analytical procedure combined with published water vapour adsorption data enabled determination of the abundance of structured water layers, ...

2008-01-15

412

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

Abstract: Snake venom contains a number of small proteins,enzymes and other components,which displays a broad spectrum of biological activities. With the ability of specifically binding on acetylcholine acceptor, alpha-bungarotoxins are not only useful molecular probes in investigating the mechanism of neural signal transmission, but also potential pharmic preparations for neural disease treatment. In current research,cDNAs of Bungarus multicinutus venom gland were synthesized using SMART cDNA amplification kit and then, alpha-bungarotoxin genes were cloned and sequenced. Total of 20 clones were sequenced representing 14 isotoxin mRNAs of alpha-bungarotoxins. Among those clones, a novel isotoxin gene was subcloned into two expression plasmids, alpha-BgTX/pQE30a and alpha-BgTX/pGEX-4T-1, and transformed into E. coli. After inducing with IPTG, fused protein of GST-alpha-BgTX was successfully expressed at level of 30% gross proteins of bacteria. More than 25% of fused ...

2005-07-01

413

Treatment of waste rock piles at Wood Cadillac using a reducing trickling filter; Traitement des resurgences du parc a residus miniers Wood Cadillac au moyen d'un biofiltre reducteur

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

2002-12-01

414

Toxicological benchmarks for screening potential contaminants of concern for effects on soil and litter invertebrates and heterotrophic process

The Ministere des Ressources naturelles du Quebec (Quebec Natural Resources Department) implemented a remedial program to treat the waste rock pile at Wood Cadillac, located near Cadillac, in Abitibi, Quebec. The solutions proposed by INRS-Georessources and ENVIROCONSEIL are aimed at eliminating erosion and stabilizing the geochemical processes. Part of the proposed solution also included the use of a reducing trickling filter for the treatment of acid leachates, which also contain arsenic when exiting the waste rock pile. The trickling filter is composed of forest tailings in which the bacteria reduce the sulphates and stimulate the precipitation of arsenic into arsenic sulphates. This is a new treatment that was developed following laboratory experiments which demonstrated the feasibility of the process and quantified the parameters. A demonstration unit was constructed by ENVIROCONSEIL and installed at the Wood Cadillac waste rock pile under the supervision of ...

2000-07-01

415

The multidrug resistance efflux complex, EmrAB from Escherichia coli forms a dimer in vitro

One of the initial stages in ecological risk assessments for hazardous waste sites is the screening of contaminants to determine which of them are worthy of further consideration as open-quotes contaminants of potential concern.close quotes This process is termed open-quotes contaminant screening.close quotes It is performed by comparing measured ambient concentrations of chemicals to benchmark concentrations. Currently, no standard benchmark concentrations exist for assessing contaminants in soil with respect to their toxicity to soil- and litter-dwelling invertebrates, including earthworms, other micro- and macroinvertebrates, or heterotrophic bacteria and fungi. This report presents a standard method for deriving benchmarks for this purpose, sets of data concerning effects of chemicals in soil on invertebrates and soil microbial processes, and benchmarks for chemicals potentially associated with United States Department of Energy sites. In addition, literature ...

416

Sulfur and carbon cycling in a flue gas desulfurization sludge disposal site.

Tripartite efflux systems are responsible for the export of toxins across both the inner and outer membranes of Gram negative bacteria. Previous work has indicated that EmrAB-TolC from Escherichia coli is such a tripartite system, comprised of EmrB an MFS transporter, EmrA, a membrane fusion protein and TolC, an outer membrane channel. The whole complex is predicted to form a continuous channel allowing direct export from the cytoplasm to the exterior of the cell. Little is known, however, about the interactions between the individual components of this system. Reconstitution of EmrA + EmrB resulted in co-elution of the two proteins from a gel filtration column indicating formation of the EmrAB complex. Electron microscopic single particle analysis of the reconstituted EmrAB complex revealed the presence of particles approximately 240 x 140 A, likely to correspond to two EmrAB dimers in a back-to-back arrangement, suggesting the dimeric EmrAB form is the ...

2009-03-06

417

Study on biosorption kinetics and thermodynamics of uranium by Citrobacter freudii

Products of a power plant flue gas desulfurization scrubber are discharged into a pond as sludge consisting of calcite (initial delta13C 3.2-3.8 per thousand), gypsum (initial delta34S 7.6-8.6 per thousand), and aqueous solution. Reducing conditions exist below a boundary that appears to move vertically as a function of changes in pond water level. Under reducing conditions, bacteria partially reduce aqueous sulfate to low-delta34S sulfide, consuming organic carbon and generating low-delta13C bicarbonate. Under oxidizing conditions, sulfide is converted to sulfate, leading to calcite dissolution, gypsum precipitation, and isotopic re-equilibration of remaining calcite with dissolved bicarbonate near the pond surface. The gypsum has delta34S near 6 per thousand, and calcite has delta13C as low as -1.7 per thousand; the changes from initial values correspond to predictions based on isotopic balance and reaction stoichiometry. The pond largely contains the products of ...

2003-04-01

418

Report on a survey in fiscal 1999. Survey on industrial utilization of microorganism reaction mechanisms under anaerobic condition; 1999 nendo kenki jokenka ni okeru biseibutsu hanno kiko no kogyoteki riyo ni kansuru chosa hokokusho

Biosorption has been developed as an effective and economic method to treat wastewater containing low concentrations of metal pollutants. In this study, a bacterium, Citrobacter freudii, was used as a biosorbent to adsorb uranium ions. The thermodynamics and kinetics of this adsorption, as well as its mechanism, were investigated. The results indicated that the biosorption rate could be better described by a pseudo 2nd-order model than a pseudo 1st-order model. The adsorption of U (VI) proceeded very rapidly in the first 30 min and subsequently slowed down continuously for a long period. The biosorption isotherm of uranium by C. freudii could be described well by the Langmuir or Freundlich isotherm, and the latter was better. The thermodynamics parameters, {delta}H{sup o}, {delta}G{sup o}, and {delta}S{sup o} were calculated according to the results of the experiment, which showed this biosorption as being endothermic and spontaneous. The authors investigated the active sites of ...

2008-01-15

419

Quantification of antibiotic drug potency by a two-compartment radioassay of bacterial growth

Industrial utilization of reaction mechanisms of microorganisms under anaerobic condition permits structuring energy saving type production processes. The present survey has investigated features of new microorganisms under anaerobic condition and the status of researches thereon inside and outside the country, and discussed their future applications. Chapter 1 compares anaerobic microorganisms and functions of microorganism under anaerobic condition with those aerobic to describe their general features, and describes the purpose of this survey and the summary of the investigations. Chapter 2 surveys the current status of technologies to utilize microorganisms under anaerobic condition. Chapter 3 outlines metabolic characteristics of the anaerobic microorganisms, and extracts functions effective for material production by different anaerobic microorganisms to describe their applicability. Chapter 4 evaluates the system classification for the anaerobic microorganisms utilizing the basic ...

2000-03-01

420

Methanogens and sulfate-reducing bacteria in oil sands fine tailings waste.

The two-compartment radioassay for microbial kinetics based on continuous measurement of the {sup 14}CO{sub 2} released by bacterial metabolism of 14C-labeled substrate offers a valuable approach to testing the potency of antimicrobial drugs. By using a previously validated radioassay with gram-positive and gram-negative bacteria, a group of protein synthesis inhibitors was evaluated for their effect on microbial growth kinetics. All tested drugs induced changes in both the slopes and intercepts of the growth curves. An exponential growth model was applied to quantify the drug effect on the processes of bacterial {sup 14}CO{sub 2} liberation and cell generation. The response was measured in terms of a generation rate constant. A linear dependence of the generation rate constant on the dose of spectinomycin was observed with Escherichia coli. Sigmoidal-shaped curves were found in the assays of chloramphenicol and tetracycline. The implications of dose-response ...

1990-06-01

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421

Intracellular monitoring of superoxide dismutase expression in an Escherichia coli fed-batch cultivation using on-line disruption with at-line surface plasmon resonance detection.

In the past decade, the large tailings pond (Mildred Lake Settling Basin) on the Syncrude Canada Ltd. lease near Fort McMurray, Alta., has gone methanogenic. Currently, about 60%-80% of the flux of gas across the surface of the tailings pond is methane. As well as adding to greenhouse gas emissions, the production of methane in the fine tailings zone of this and other settling basins may affect the performance of these settling basins and impact reclamation options. Enumeration studies found methanogens (10(5)-10(6) MPN/g) within the fine tailings zone of various oil sands waste settling basins. SRB were also present (10(4)-10(5) MPN/g) with elevated numbers when sulfate was available. The methanogenic population was robust, and sample storage up to 9 months at 4 degrees C did not cause the MPN values to change. Nor was the ability of the consortium to produce methane delayed or less efficient after storage. Under laboratory conditions, fine tailings samples released 0.10-0.25 mL CH4 ...

2000-10-01

422

Increase of unsaturated fatty acids under high pressure in a deep-sea bacterium; Shinkai kara bunrisareta taiatsusei biseibutsu DSS12 kabu no baiyo ondo, baiyo atsuryoku to kintai shibosan sosei no henka

An on-line cell disruption system for at-line monitoring of the intracellular concentration of recombinant human superoxide dismutase (rhSOD) in a genetically modified Escherichia coli strain, HMS174(DE3) (pET11a/rhSOD), in bioreactor cultivations is described. The sampled bacteria were disrupted on-line by rapid mixing with a nonionic detergent. The recombinant protein content of the lysed bacterial sample was quantitated by a subsequent surface plasmon resonance biosensor with a specific monoclonal antibody. Extraction efficiency of the monitoring system was optimized with respect to the flow rate ratio of the cell suspension and the detergent at relevant cell densities with the aim to attain rapid monitoring. Monitoring was demonstrated for a shake flask culture and a glucose-limited fed-batch cultivation. The results are compared with a traditional enzyme-linked immunosorbent assay method showing a correlation coefficient of R2 = 0.97. Extraction efficiency of ...

2005-07-01

423

Impact of climate change on carbon cycle in freshwater ecosystems

A cellular membrane exchanges substances into and from the cell and protects the cell interior by maintaining semi-fluidity rather than be being solid. It is known that microorganisms maintain the fluidity in correspondence with varying environmental temperatures by changing and adjusting the composition of fatty acids which constitute the cellular membrane lipids. As part of the studies to elucidate the pressure withstanding mechanism in deep-sea bacteria, this paper investigates what variations the fatty acid composition, which constitutes cellular membranes of the DSS12 strain, a pressure withstanding bacterium growing well under either normal pressure or high pressures, will show under different culturing temperatures and pressures. Culture under low temperatures and culture under high pressures increase content of unsaturated fatty acids including icosapentanoic acid. Culture under high temperatures or normal pressure increases content of such unsaturated ...

1997-03-01

424

Identification of sucrose binding, membrane proteins using a photolyzable sucrose analog. [P. saccharophila

The impacts of the expected climate change on Finnish lake ecosystems were studied with the biota of the mesohumic Lake Paeaejaervi, southern Finland. Experimental conditions, from small-scale experiments on single species level to a large-scale ecosystem manipulation, were established to simulate directly the future climate and/or loading of nutrients and dissolved organic matter (DOM) from the drainage area. The experimental studies were accomplished by modelling the carbon flow in the pelagic food web as well as the growth of littoral macrophytes. The main hypothese tested were as follows: As a consequence of the climate change (rising temperature and increasing precipitation) the loading of nutrients and dissolved organic matter (DOM) from the drainage area to the lake will increase. In the pelagic zone this will be first reflected i higher productivity of primary producers and bacteria, but will later affect the entire food chain. Increase in atmospheric ...

1996-12-31

425

IAEA RESEARCH CONTRACTS SECOND ANNUAL REPORT. Technical Reports Series No. 9

The sucrose derivative 6'-deoxy-6'-(2-hydroxy-4-azido)benzamidosucrose (6'-HABS) was prepared from sucrose (via 6'-deoxy-6'-aminosucrose) and 4-amino-salicylic acid. 6'-HABS is a competitive inhibitor of sucrose influx into protoplasts from developing soybean cotyledons and of sucrose binding to membranes from the bacteria P. saccharophila. The Ki for inhibition in the soybean protoplasts was 75..mu..M. 6'-Deoxy-6'-(2-hydroxy-3-/sup 125/Iodo-4-azido)benzamidosucrose was prepared by lactoperoxidase iodination of 6'-HABS. Upon photolysis in the presence of membranes from P saccharophila, label from the photoprobe is incorporated into a sucrose inducible polypeptide of mass 84 KD in SDS-PAGE. The polypeptide is protected from labeling by the inclusion of sucrose in the photolysis mixture. Photolysis conditions which lead to specific labeling of the sucrose protectable polypeptide in ...

1986-04-01

426

Geochemical study on origin of natural gases in Japanese oil and gas fields

Summaries are presented for those research contracts which expired between December 31, 1960 and December 31, 1981. Topics covered include: factors controlling distribution of fission products in biosphere, non-destructive methods of evaluating the U/sup 235/ and Pu content of irradiated fuel elements, studies of contamination in local marine resources, tracer studies of anemia, non-destructive analysis of irradiated fuel elements using a flux integrating monitor, mechanism of proteolysis of I/sup 131/-labeled fibrinogen, radiosensitivity of spermatogonia of Drosophila melel elements by gamma scanning, uptake and loss of radioactive material by marine bacteria, factors which influence the movement of radioactive strontium from soils to plants, biological concentration of fission products in mollusks from water, decay scheme of Tl/sup 210/, calcium balance in metabolic bone disease, development of radioactive drugs with special reference ...

1962-01-01

427

Genetic engineering of group 2 sigma factor SigE widely activates expressions of sugar catabolic genes in Synechocystis species PCC 6803.

The origin of natural gas in the Japanese oil and gas fields are geochemically studied. Samples are taken from structural natural gas, surface gas seepage, water-dissolved natural gas and coal-field gas of the Japan Sea coast area. The origins of primary hydrocarbons are classified into bacteria gas and thermogenic gas, the latter being subclassified into gas in oil production zone with the per million deviation of the carbon isotope (/sup 13/C/sup 1/) of methane less than -35 and those gases with maturity higher than this. Surface gas seepage is subjected to migration and bacterial oxidation. Coal gas is similar to oil gas. The CO/sub 2/ concentration is 0 - 2% and /sup 13/CO/sub 2/ deviations from -30 - +30. The origin can be barely estimated from the isotopic composition because of the wide secondary change in the composition. The origin and migration of gas from the gas field of northern Niigata are not similar to those in the southern area, which consist of a ...

1988-05-01

428

Gene expression analysis after low dose ionising radiation exposure of the developing organism

Metabolic engineering of photosynthetic organisms is required for utilization of light energy and for reducing carbon emissions.Control of transcriptional regulators is a powerful approach for changing cellular dynamics, because a set of genes is concomitantly regulated. Here, we show that overexpression of a group 2 ? factor, SigE, enhances the expressions of sugar catabolic genes in the unicellular cyanobacterium, Synechocystis sp. PCC 6803. Transcriptome analysis revealed that genes for the oxidative pentose phosphate pathway and glycogen catabolism are induced by overproduction of SigE. Immunoblotting showed that protein levels of sugar catabolic enzymes, such as glucose-6-phosphate dehydrogenase, 6-phosphogluconate dehydrogenase, glycogen phosphorylase, and isoamylase, are increased. Glycogen levels are reduced in the SigE-overexpressing strain grown under light. Metabolome analysis revealed that metabolite levels of the TCA cycle and acetyl-CoA are significantly altered by SigE ...

2011-07-11

429

Formation of colloidal silver nanoparticles stabilized by Na+-poly(gamma-glutamic acid)-silver nitrate complex via chemical reduction process.

Measuring gene expression using microarrays is relevant to many areas of biology and medicine, such as follow up of developmental stages and diseases onset, and treatment study. Since there can be tens of thousands of distinct probes on an array, each micro array experiment can accomplish the equivalent number of genetic tests in parallel. Arrays have therefore dramatically accelerated many types of investigations. For example, microarrays can be used to identify stress response genes by comparing gene expression in challenged versus normal cells. In the Molecular and Cellular Biology lab (MCB), the micro array experiments are performed within the Genomic Platform, fully equipped to analyse either the behaviour of bacteria during long space flight, the effect of low dose ionising radiation on the developing organism in mice, or the human individual radiation sensitivity. For the low dose effect, two main stages of development are of interest; 1) the gastrula stage ...

2007-09-01

430

Evolution of a molecular switch: universal bacterial GTPases regulate ribosome function.

Macromolecular and polyanionic Na(+)-poly(gamma-glutamic acid) (PGA) silver nitrate complex acted as both a metal ion provider and a particle protector to fabricate nanosized silver colloids under chemical reduction by dextrose. The formation and size of particles have been characterized from transmission electron microscopy (TEM), dynamic light scattering analysis and UV-vis spectrophotometer. The results showed that the average particle size was 17.2+/-3.4 to 37.3+/-5.5 nm, apparently depending on the complex concentration. It was found that the rate constant and conversion of silver nanoparticles were proportional to the concentration of PGA. The growth mechanism of nanosized silver colloid was fully discussed. In addition, the in vitro cytotoxicity evaluated by L929 fibroblasts proliferation and antibacterial activity against Gram-positive strain (methicillin-resistant S. aureus (MRSA)) and Gram-negative strain (P. aeruginosa) bacteria have been assessed. ...

2007-05-18

431

Evaluation of heavy-metal ion toxicity in fish cells using a combined stress protein and cytotoxicity assay

The GTPases comprise a protein superfamily of highly conserved molecular switches adapted to many diverse functions. These proteins are found in all domains of life and often perform essential roles in fundamental cellular processes. Analysis of data from genome sequencing projects demonstrates that bacteria possess a core of 11 universally conserved GTPases (elongation factor G and Tu, initiation factor 2, LepA, Era, Obg, ThdF/TrmE, Ffh, FtsY, EngA and YchF). Investigations aimed at understanding the function of GTPases indicate that a second conserved feature of these proteins is that they elicit their function through interaction with RNA and/or ribosomes. An emerging concept suggests that the 11 universal GTPases are either necessary for ribosome function or transmitting information from the ribosome to downstream targets for the purpose of generating specific cellular responses. Furthermore, it is suggested that progenitor GTPases were early regulators of RNA ...

2001-07-01

432

Evaluation of chicken manure, kenaf, and phanerochaete chrysosporium (white rot fungus) as enhancers of polychlorinated biphenyl biodegradation

All organisms, from bacteria and yeast to humans, respond to physical and chemical stressors by increasing the synthesis of a small group of cellular stress proteins.'' The authors have developed a simple in vitro system for quickly screening environmentally relevant stressors to detect stress-induced proteins that are good candidates for biomarkers. Polyacrylamide gel electrophoresis was used to detect stressor-induced, concentration-dependent changes in cellular stress protein levels in two fish cell culture systems, whereas simultaneous in vitro neutral red uptake cytotoxicity assays measured the stressors effect on cellular physiology. There was a direct concentration-dependent relationship between sublethal cytotoxic effects and the increases in stress protein levels. Increases of 50 to 200% were detected in stress proteins from desert topminnow, Poeciliopsis lucida, hepatoma-derived cell cultures exposed to cadmium or copper. Three proteins ...

1994-08-01

433

Enzymatic mechanism in low chloride media: influence of glucose oxidase on the electrochemical behaviour of AISI 316L stainless steel; Mecanisme enzymatique en milieux faiblement chlorures: influence de la glucose oxydase sur le comportement electrochimique de l'acier inoxydable AISI 316L

In this 150-day study, chicken manure, kenaf, and white rot fungus were added to soil microcosms in an attempt to enhance the degradation of polychlorinated biphenyls. The soil was contaminated with commercial PCB mixtures. Dishes were ammended with 5% dry weight chicken manure, 1% dry weight kenaf, and 1% dry weight kenaf plus Phanerochaete chrysosporium inoculant. PCB concentrations were determined at 30 day intervals by soxhlet extraction and gas chromatography analyses. Preliminary results of microbial populations and PCB degradation are presented. At 90 days, the microcosms amended with chicken manure had significantly higher populations of bacteria, fungi, and actinomycetes. However, at 120 days, these soils underwent great reductions in actinomycete and bacterial populations. Through 60 days, the concentration of the PCBs Aroclor 1242 and 1248 had its greatest reduction in the kenaf amended soils. The concentration of Aroclor 1260 either increased or stayed ...

1995-12-31

434

Engineering of a psychrophilic bacterium for the bioremediation of aromatic compounds

The open circuit potential (OCP) of stainless steels immersed in natural waters generally increases with time. This phenomenon is strongly linked to the formation of a bio-film on the surface. Several studies have proved that the bio-film modifies the reaction of reduction of dissolved oxygen and that it acts mainly on the cathodic processes. One of the hypotheses explaining the action of the bio-film involves certain bacteria which use dissolved oxygen and extracellular enzymes to produce reactive oxygen species. Among this kind of metabolites is hydrogen peroxide H{sub 2}O{sub 2}. This compound interacts with the passive layer of stainless steels and affects their electrochemical behaviour, even when the chloride concentration is low. The aim of this work is to study the influence of an enzymatic reaction (of the oxidoreductase type) on anodic and cathodic processes on AISI 316L stainless steel. Experiments are carried out in two artificial electrolytes ...

2006-07-01

435

Does adenine incorporation into nucleic acids measure total microbial production:: a response to comments by Fuhrman et al

Microbial degradation of aromatic hydrocarbons has been studied with the aim of developing applications for the removal of toxic compounds. Efforts have been directed toward the genetic manipulation of mesophilic bacteria to improve their ability to degrade pollutants, even though many pollution problems occur in sea waters and in effluents of industrial processes which are characterized by low temperatures. From these considerations the idea of engineering a psychrophilic microorganism for the oxidation of aromatic compounds was developed.In a previous paper it was demonstrated that the recombinant Antarctic Pseudoalteromonas haloplanktis TAC125 (PhTAC/tou) expressing a toluene-o-xylene monooxygenase (ToMO) is able to convert several aromatic compounds into corresponding catechols. In our work we improved the metabolic capability of PhTAC/tou cells by combining action of recombinant ToMO enzyme with that of the endogenous P. haloplanktis TAC125 laccase-like ...

2010-01-27

436

Control of microbially generated hydrogen sulfide in produced waters

The uptake and incorporation of (/sup 3/H)adenine as a measure of total microbial (bacteria and unicellular algae) nucleic acid synthesis depends on the validity of several assumptions. A unique characteristic of the (/sup 3/H)adenine method is the ability to measure the specific radioactivity (nCi pmol/sup -1/) of the immediate precursor pool of the adenine incorporated into nucleic acids. This measurement permits correction for isotope dilution when the added radiotracer mixes with exogenous pools of structurally related compounds before uptake and with endogenous pools after transport into the cells. The immediate precursors to (/sup 3/H)adenine incorporation into cellular RNA and DNA are ATP and dATP. Since the intracellular dATP pool is in isotopic equilibrium with the ATP pool, one can determine the specific radioactivity of both precursor pools by measuring that of the intracellular ATP pool. If the specific activity of the precursor pool is not measured, ...

1986-11-01

437

Containment of genetically engineered organisms after application to subsurface environments. Technical completion report

Production of hydrogen sulfide in produced waters due to the activity of sulfate-reducing bacteria (SRB) is a potentially serious problem. The hydrogen sulfide is not only a safety and environmental concern, it also contributes to corrosion, solids formation, a reduction in produced oil and gas values, and limitations on water discharge. Waters produced from seawater-flooded reservoirs typically contain all of the nutrients required to support SRB metabolism. Surface processing facilities provide a favorable environment in which SRB flourish, converting water-borne nutrients into biomass and H{sub 2}S. This paper will present results from a field trial in which a new technology for the biochemical control of SRB metabolism was successfully applied. A slip stream of water downstream of separators on a produced water handling facility was routed through a bioreactor in a side-steam device where microbial growth was allowed to develop fully. This slip stream was then ...

1995-12-31

438

Complete genome sequence of Conexibacter woesei type strain (ID131577T)

The feasibility of containing genetically engineered bacteria with enhanced dehalogenating properties for in situ bioremediation was investigated. (1) An agarose matrix microbead protocol and a detection system for contained microorganisms or DNA were developed. Multiplex Polymerase Chain Reaction (PCR) allowed tracking of a consortium of encapsulated organisms or several gene targets from a single species. Gene sequences encoding the enzymes responsible for initiating the biodegradation of toluene, octane, and 2,4-D were detected by multiplex PCR and nucleic acid probes from similar to 1-10 biodegradative cells/g soil. Improved DNA extraction methods resulted in PCR reactions detecting similar to 6 cells/g soil. (2) The pcpB gene (for the broad-spectrum detoxicant pentachlorophenol (PCP) hydroxylase) isolated from Flavobacterium sp. strain ATCC 39723 was used in attempts to develop an improved dehalogenating recombinant microorganism for containment experiments.

1993-06-01

439

Complete genome sequence of Actinosynnema mirum type strain (101T)

The genus Conexibacter (Monciardini et al. 2003) represents the type genus of the family Conexibacteraceae (Stackebrandt 2005, emend. Zhi et al. 2009) with Conexibacter woesei as the type species of the genus. C. woesei is a representative of a deep evolutionary line of des-cent within the class Actinobacteria. Strain ID131577T was originally isolated from temperate forest soil in Gerenzano (Italy). Cells are small, short rods that are motile by peritrichous fla-gella. They may form aggregates after a longer period of growth and, then as a typical charac-teristic, an undulate structure is formed by self-aggregation of flagella with entangled bacteri-al cells. Here we describe the features of the organism, together with the complete sequence and annotation. The 6,359,369 bp long genome of C. woesei contains 5,950 protein-coding and 48 RNA genes and is part of the Genomic Encyclopedia of Bacteria and Archaea project.

2010-01-01

440

Competition by inhibitory oligonucleotides prevents binding of CpG to C-terminal TLR9

Actinosynnema mirum Hasegawa et al. 1978 is the type species of the genus, and is of phylogenetic interest because of its central phylogenetic location in the Actino-synnemataceae, a rapidly growing family within the actinobacterial suborder Pseudo-nocardineae. A. mirum is characterized by its motile spores borne on synnemata and as a producer of nocardicin antibiotics. It is capable of growing aerobically and under a moderate CO2 atmosphere. The strain is a Gram-positive, aerial and substrate mycelium producing bacterium, originally isolated from a grass blade collected from the Raritan River, New Jersey. Here we describe the features of this organism, together with the complete genome sequence and annotation. This is the first complete genome sequence of a member of the family Actinosynnemataceae, and only the second sequence from the actinobacterial suborder Pseudonocardineae. The 8,248,144 bp long single replicon genome with its 7100 protein-coding and 77 RNA genes is part of the ...

2009-05-20

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25

441

British Library Electronic Table of Contents (United Kingdom)

Abstract TLR9 recognizes unmethylated CpG-containing DNA commonly found in bacteria. Synthetic oligonucleotides containing CpG-motifs (CpG ODNs) recapitulate the activation of TLR9 by microbial DNA, whereas inversion of the CG dinucleotide within the CpG motif to GC (GpC ODNs) renders such ODNs inactive. This difference cannot be attributed to binding of ODNs to the full-length TLR9 ectodomain, as both CpG and GpC ODNs bind comparably. Activation of murine TLR9 requires cleavage into an active C-terminal fragment, which binds CpG robustly. We therefore compared the ability of CpG and GpC ODNs to bind to full-length and C-terminal TLR9, and their impact on the cleavage of TLR9. We found that CpG binds better to C-terminal TLR9 when compared with GpC, despite comparably low binding of both O...

2011-01-01

442

Characteristics of volatile fatty acid decomposition in anaerobic fluidized bed

Anaerobic degradation of DCM diffusing through clay

The growth kinetics constants and concentration of active attached biomass in an anaerobic fluidized bed which decomposes acetic, propionic and butyric acid were estimated. The mixture of above mentioned fatty acids was supplied to the fluidized bed in the range of hydraulic retention time (HRT) from 0.25 to 2 days. After the effluent reached in a steady state in quality, batch experiments were conducted separately with each fatty acid as a substrate in order to investigate the decomposition characteristics of each substrate by attached biomass. In order to estimate the parameter values of the growth kinetics of the bacteria, batch experiments were also conducted under the completely mixed condition using detached biomass from a support material. The changes of fatty acid concentrations with time were clearly expressed with the Monod growth model. Maximum specific substrate decomposition rates and saturation constants, and active biomass concentrations were ...

1988-06-01

443

Adaptation of oral streptococci to low pH.

Two series of diffusion tests were performed to examine the degradation of dichloromethane (DCM) as it diffuses through clay. The first series showed the use of a synthetic leachate with no significant initial bacterial population diffusing through a plug of intact clay; there was an induction period of 95--135 d, during which diffusion was as expected in the absence of degradation, followed by a second stage, where degradation occurred with an apparent half-life of less than 55 d at a temperature of 24 C. The second series of tests examined the diffusion of an actual leachate from the Keele Valley Landfill (KVL) (which provided both nutrients and a source of bacteria), through a compacted clay. In these tests, the induction period was reduced to 40--60 d, after which the apparent half-life was 20 d or less at 27 C. The diffusion coefficient for DCM was approximately 8 {times} 10{sup {minus}10} m{sup 2}/s, with partitioning coefficient K{sub d} = 1.5 cm{sup 3}/g. ...

1997-12-01

444

Activity of Citrus Essential Oils against-Escherichia coli-O157:H7 and-Salmonella-spp. and Effects on Beef Subprimal Cuts under Refrigeration

The strategies employed by oral streptococci to resist the inimical influences of acidification reflect the diverse and dynamic niches of the human mouth. All of the oral streptococci are capable of rapid degradation of sugar to acidic end-products. As a result, the pH value of their immediate environment can plummet to levels where glycolysis and growth cease. At this point, the approaches for survival in acid separate the organisms. Streptococcus mutans, for example, relies on its F-ATPase, to protect itself from acidification by pumping protons out of the cells. S. salivarius responds by degrading urea to ammonia and S. sanguis produces ammonia by arginolysis. The mechanisms by which these organisms regulate their particular escape route are now being explored experimentally. The picture that emerges is that the acid-adaptive regulatory mechanisms of the oral streptococci differ markedly from those employed by Gram-negative bacteria. What remains to be ...

2000-01-01

445

British Library Electronic Table of Contents (United Kingdom)

Abstract:- Escherichia coli-O157:H7 and-Salmonella-spp. are bacterial pathogens often associated with beef, and cause many cases of foodborne illness each year in the United States. During beef slaughter and processing, these bacteria may spread from the hide or intestines to the carcass. The objective of this research was to investigate the use of naturally occurring compounds citrus essential oils (CEOs) extracted from orange peel to reduce or eliminate these pathogens at the chilling stage of processing, or during fabrication. Brisket flats (used to simulate beef subprimals) were spot inoculated with approximately 6 log of surrogate generic-E. coli-cocktail (previously shown to be identical in growth and survival parameters to-E. coli-O157:H7 and-Salmonella-spp.). Following drying, CEOs...

2011-01-01

446

Active packaging of ground beef patties by edible zein films incorporated with partially purified lysozyme and Na2EDTA

British Library Electronic Table of Contents (United Kingdom)

Summary In this study, antimicrobial activity of zein films incorporated with partially purified lysozyme and disodium ethylenediaminetetraacetic acid (Na2EDTA) has been tested on selected pathogenic bacteria and refrigerated ground beef patties. The developed films containing 700-g-cm-2 lysozyme and 300-g-cm-2 Na2EDTA showed antimicrobial activity on Listeria monocytogenes, Escherichia coli O157:H7, and Salmonella typhimurium. The application of lysozyme and Na2EDTA incorporated zein films on beef patties significantly decreased total viable counts (TVC) and total coliform counts after 5-days of storage compared to those of control patties (P-2EDTA or Na2EDTA alone significantly slowed down the oxidative changes in patties during storage (P-P-2EDTA for active packaging of refrigerated mea...

2011-01-01

447

A fluorescent aminolipid from a green photosynthetic bacterium

On the impact of low power density microwaves in some living tissues

A preliminary chemical characterization is presented of phosphate-free aminolipids isolation from Chlorobium limicola f. thiosulfatophilum. The lipid contains no phosphorus, glycerol, sugar, ornithine, or lysine. Ultraviolet absorption and fluorescence spectra indicate that the amino moiety of the lipid is an aromatic heterocyclic compound. Infrared spectra indicate that the lipid is a secondary or tertiary amide, and gas chromatograhic analysis of the hydrolyzed lipid shows that for each 1100 g of lipid, 1 mol of myristic acid (C/sub 14:0/) is linked in an amide bond. Acid hydrolysis of the lipid yields two fluorescent substances, A (ninhydrine positive) and B (negative), in addition to myristic acid. Proton nuclear magnetic resonance (NMR) studies indicate that substance A contains a butyl groups attached to a conjugated ring carbon, two equivalent ethyl groups attached to one or two nitrogen atoms, and two downfield protons (8.4 ppm), perhaps attached to a ring carbon adjacent to a ...

1983-04-12

448

Effect of Lactobacillus supplementation with and without arginine on liver damage and bacterial translocation in an acute liver injury model in the rat.

The biomedical and ecological interest for the microwave impact on the Earth biosphere is continuously increased since the industrial, military and communication activities strongly contribute to the electromagnetic stress of living bodies. In the next the authors present some of the main results obtained regarding the microwave exposure of various types of biological material: bacteria, fungi, young plant seedlings, dry seeds, animal tissues. The electromagnetic exposure was carried out in open space in well controlled environmental conditions by using 10.75 GHz/1 m W cm{sup -2} microwaves. Biochemical assays and cytogenetic tests have been carried out to reveal the changes induced post irradiation. The response of some pathogen bacteria, have been emphasized by means of turbidimetric measurements - the stimulatory effect being noticed at the level of the microbial population density (the stimulation of the human body microbial flora seems to ...

2006-07-01

449

The role of the HCR system in the repair of lethal lesions of Bacillus subtilis phages and their transfecting DNA damaged by radiation and alkylating agents

In acute liver failure following hepatitis, toxic insults, or after major liver surgery, there is an increased bacterial translocation from the gut. This may explain some of the infectious complications seen in these conditions. To elucidate mechanisms and find possible preventive measures, we investigated the effect of rectal administration of arginine and probiotic bacteria (Lactobacillus spp.) on bacterial translocation and the extent of liver failure. Sprague-Dawley rats were used and five different Lactobacillus strains (Lb. reuteri R2LC, Lb. rhamnosus DSM 6594 (= strain 271), Lb. plantarum DSM 9843 (= strain 299v), Lb. fermentum 8704:3 (= strain 245), and Lb. reuteri (= strain 108) were administered rectally once daily for 8 days with and without 2% arginine. Acute liver injury (ALI) was induced on the eighth day by intraperitoneal injection of D-galactosamine (1.1 g/kg body weight), and samples were collected after 24 and 48 hours. Bacterial translocation ...

1997-03-01

450

The neuronal nicotinic acetylcholine receptor {alpha}7 subunit gene: Cloning, mapping, structure, and targeting in mouse

The role of the HCR system in the repair of prelethal lesions induced by UV light, #gamma# radiation and alkylating agents was studied in the Bacillus subtilis SPP1 phage, its heat sensitive mutants (N3, N73 nad ts_1) and corresponding infectious DNA. The survival of phages and their transfecting DNA after treatment with UV light is substantially higher in hcr"+ cells than in hcr cells, the differences being more striking in intact phages than in their transfecting DNA's. Repair inhibitors reduce survival in hcr"+ cells: caffeine lowers the survival of UV-irradiated phage SPP1 in exponentially growing hcr"+ cells but has no effect on its survival in competent hcr"+ cells; acriflavin and ethidium bromide decrease the survival of the UV-irradiated SPP1 phage in both exponentially growing and competent hcr"+ cells to the level of survival observed in hcr cells; moreover, ethidium bromide lowers the number of infective centres in hcr"+ cells of the UV-irradiated DNA of ...

451

The ATG1/ATG13 Protein Kinase Complex Is Both a Regulator and a Target of Autophagic Recycling in Arabidopsis.

The neuronal nicotinic acetylcholine receptor {alpha}7 subunit is a member of a family of ligand-gated ion channels, and is the only subunit know to bind {alpha}-bungarotoxin in mammalian brain. {alpha}-Bungarotoxin binding sites are known to be more abundant in the hippocampus of mouse strains that are particularly sensitive to nicotine-induced seizures. The {alpha}7 receptor is highly permeable to calcium, which could suggest a role in synaptic plasticity in the nervous system. Auditory gating deficiency, an abnormal response to a second auditory stimulus, is characteristic of schizophrenia. Mouse strains that exhibit a similar gating deficit have reduced hippocampal expression of the {alpha}7 subunit. We have cloned and sequenced the full length cDNA for the mouse {alpha}7 gene (Acra-7) and characterized its gene structure. The murine {alpha}7 shares amino acid identity of 99% and 93% with the rat and human {alpha}7 subunits, respectively. Using an interspecies backcross panel, the ...

1994-09-01

452

Role of mitochondria in sulfolipid biosynthesis by Euglena chloroplasts

Autophagy is an intracellular recycling route in eukaryotes whereby organelles and cytoplasm are sequestered in vesicles, which are subsequently delivered to the vacuole for breakdown. The process is induced by various nutrient-responsive signaling cascades converging on the Autophagy-Related1 (ATG1)/ATG13 kinase complex. Here, we describe the ATG1/13 complex in Arabidopsis thaliana and show that it is both a regulator and a target of autophagy. Plants missing ATG13 are hypersensitive to nutrient limitations and senesce prematurely similar to mutants lacking other components of the ATG system. Synthesis of the ATG12-ATG5 and ATG8-phosphatidylethanolamine adducts, which are essential for autophagy, still occurs in ATG13-deficient plants, but the biogenesis of ATG8-decorated autophagic bodies does not, indicating that the complex regulates downstream events required for autophagosome enclosure and/or vacuolar delivery. Surprisingly, levels of the ATG1a and ATG13a ...

2011-10-01

453

Relationship of DNA repair processes to mutagenesis and carcinogenesis in mammalian cells. Progress report, November 1, 1979-October 31, 1980

Sulfate activation occurs in Euglena mitochondria the authors now find that the sulfate activating enzymes are absent from Euglena chloroplasts. Cells of mutant W/sub 10/BSmL lacking plastids also lack detectable sulfolipid (SL) when grown on /sup 35/SO/sub 4//sup 2 -/ indicating that SL is absent from the mitochondria and is exclusively in the plastids. Plastids alone will convert /sup 35/S-cysteine to /sup 35/SL in the presence of ATP and Mg/sup 2 +/; light is stimulatory. Under similar conditions, chloroplasts and mitochondria incubated together convert /sup 35/SO/sub 4//sup 2 -/ to plastid-localized /sup 35/SL but either organelle incubated alone fails to effect this conversion. Unlabeled cysteine blocks SL labeling from sulfate in the mixed incubation; since cysteine is formed from sulfate by Euglena mitochrondria, cysteine (and other compounds) may move from the mitochondrion to the chloroplast to provide the sulfo group for SL formation. Although ...

1987-04-01

454

Reactive biomolecular divergence in genetically altered yeast cells and isolated mitochondria as measured by biocavity laser spectroscopy : a rapid diagnostic method for studying cellular responses to stress and disease.

The objective of this research is to determine the role of DNA repair in mutagenesis and carcinogenesis in mammalian cells. Use of the host-cell reactivation viral suicide enrichment procedure was initiated in the isolation of repair-deficient mutants. Lightly mutagenized BHK cells were infected with irradiated Herpes simplex virus (HSV); several radiation-sensitive strains were isolated among the survivors of the infection. The characterization of these strains is progressing and the enrichments are continuing. That alterations in the frequency of mutation of C3H/10T 1/2 cells, occurring as a result of holding the cells in a confluent state following treatment with ethylmethane sulfonate, parallel the alterations in the frequency of neoplastic transformation was found. The repair capabilities of BHK cells were found to be intermediate in comparison to repair-proficient and -deficient human cells with regard to the reactivation of HSV treated with various ...

455

One-step RNA pathogen detection with reverse transcriptase activity of a mutated thermostable Thermus aquaticus DNA polymerase.

We report an analysis of four strains of baker's yeast (Saccharomyces cerevisiae) using biocavity laser spectroscopy. The four strains are grouped in two pairs (wild type and altered), in which one strain differs genetically at a single locus, affecting mitochondrial function. In one pair, the wild-type rho+ and a rho0 strain differ by complete removal of mitochondrial DNA (mtDNA). In the second pair, the wild-type rho+ and a rho- strain differ by knock-out of the nuclear gene encoding Cox4, an essential subunit of cytochrome c oxidase. The biocavity laser is used to measure the biophysical optic parameter Deltalambda, a laser wavelength shift relating to the optical density of cell or mitochondria that uniquely reflects its size and biomolecular composition. As such, Deltalambda is a powerful parameter that rapidly interrogates the biomolecular state of single cells and mitochondria. Wild-type cells and mitochondria produce Gaussian-like distributions with a single peak. In ...

2006-12-01

456

Novel method for differentiation between Trastuzumab and host adaptive response.

We describe the cloning and characterization of a mutated thermostable DNA polymerase from Thermus aquaticus (Taq) that exhibits an increased reverse transcriptase activity and is therefore designated for one-step PCR pathogen detection using established real-time detection methods. We demonstrate that this Taq polymerase mutant (Taq M1) has similar PCR sensitivity and nuclease activity as the respective Taq wild-type DNA polymerase. In addition, and in marked contrast to the wild-type, Taq M1 exhibits a significantly increased reverse transcriptase activity especially at high temperatures (>60 degrees C). RNA generally hosts highly stable secondary structure motifs, such as hairpins and G-quadruplexes, which complicate, or in the worst case obviate, reverse transcription (RT). Thus, RT at high temperatures is desired to weaken or melt secondary structure motifs. To demonstrate the ability of Taq M1 for RNA detection of pathogens, we performed TaqMan probe-based ...

2010-02-01

457

Murine antibody response to oral infection with live aroA recombinant Salmonella dublin vaccine strains expressing filamentous hemagglutinin antigen from Bordetella pertussis.

Humoral immune response to human epidermal growth factor receptor 2 (HER-2/neu or ErbB-2) has been detected in sera of breast cancer patients and shown to be an appropriate prognostic marker (Taylor et al., 2007). However, since Trastuzumab (Herceptin) is a widely used monoclonal antibody as cancer therapy agent for tumors over-expressing HER-2, there is a need for an efficient way to detect host-generated antibodies against HER-2 without the confounding effect of Herceptin. Here we describe a screening method developed to decipher between host antibodies against HER-2 and that of Herceptin. By producing a series of truncation mutants within the epitope of Herceptin, we were able to inhibit this binding. We demonstrated also that by a three amino acid substitution (PPF?SSS) we were able to abrogate Herceptin binding while generating a highly conserved HER-2 extracellular domain (ECD). By producing a stable cell line that expresses this mutated form of the human ...

2011-06-08

458

Missense mutations in the growth hormone receptor dimerization region in Laron syndrome

Two plasmids which express either nearly intact or truncated filamentous hemagglutinin (FHA) from Bordetella pertussis and which are marked with a tetracycline resistance (Tcr) gene were transformed into Salmonella dublin SL1438, an aroA deletion mutant intended for use as an attenuated oral vaccine against salmonellosis. These S. dublin recombinants, when fed to mice, induced serum immunoglobulin, immunoglobulin M (IgM), and sometimes IgA antibody responses to FHA and S. dublin. In addition, IgA antibodies against FHA were found in gut wash fluids. S. dublin carrying pDB2300, a multicopy plasmid encoding truncated FHA protein, induced a better antibody response than did S. dublin carrying pDB2000, a low-copy-number plasmid encoding full-sized FHA. Administration of tetracycline to mice enhanced the stability of recombinant plasmids, and tetracycline-treated mice developed higher anti-FHA titers. Although neither strain examined is suitable for use in a human oral ...

1990-08-01

459

Development of radiological emergency preparedness technology

Laron syndrome (LS) is an autosomal recessively inherited condition characterized by insensitivity to endogenous and exogenous GH. Affected individuals have severe episodes and other characteristic features. GH receptor gene mutations are present in all affected individuals in whom molecular studies have been reported. The GH receptor is a plasma membrane-spanning protein in which the extracellular domain binds circulating GH and the intracellular domain interacts with the JAK-2 kinase and possibly other intracellular signaling molecules. GH receptor dimerization occurs on GH binding and is thought to be required for normal signal transduction. We have studied the GH receptor genes of four unrelated individuals affected with LS from the United States, Italy, Saudi Arabia, and India. We have identified four different missense mutations that alter consecutive amino acids 152 to 155 in or near the dimerization domain of the GH receptor. One of these mutations, D152H, has been reported ...

1994-09-01

460

Control of Electrostatic Interactions Between F-Actin And Genetically Modified Lysozyme in Aqueous Media

Large-scale field tracer experiments have been conducted on Ulchin, Wolsung and Daeduk sites for the purpose of validating FADAS and of analyzing the environmental characteristics around the nuclear sites. The most influential factor in atmospheric dispersion is the meteorological condition. During the experiment, meteorological data were measured on the release point and the selected positions among sampling points. Once radioactive materials are released to the atmosphere, members of public may be exposed through the environmental media such as air, soil and foods. Therefore, to protect the public, adequate countermeasures should be taken at due time for those exposure pathways. both processes, of justification and optimization are applied to a countermeasure simultaneously for decision-making. The work scope of Biological research for the radiation protection had contained the search of biological microanalytic methods for assessing the health effect by {gamma}-radiation and toxic ...

2000-04-01

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25

461

Characterization of the human lipoprotein lipase (LPL) promoter: Evidence of two cis-regulatory regions, LP-[alpha] and LP-[beta] of importance for the differentation-linked induction of the LPL gene during adipogenesis

The aim for deterministic control of the interactions between macroions in aqueous media has motivated widespread experimental and theoretical work. Although it has been well established that like-charged macromolecules can aggregate under the influence of oppositely charged condensing agents, the specific conditions for the stability of such aggregates can only be determined empirically. We examine these conditions, which involve an interplay of electrostatic and osmotic effects, by using a well defined model system composed of F-actin, an anionic rod-like polyelectrolyte, and lysozyme, a cationic globular protein with a charge that can be genetically modified. The structure and stability of actin-lysozyme complexes for different lysozyme charge mutants and salt concentrations are examined by using synchrotron x-ray scattering and molecular dynamics simulations. We provide evidence that supports a structural transition from columnar arrangements of F-actin held ...

2009-06-04

462

Atomic substitution reveals the structural basis for substrate adenine recognition and removal by adenine DNA glycosylase

When preadipocytes differentiate into adipocytes, several differentiation-linked genes are activated. Lipo-protein lipase (LPL) is one of the first genes induced during this process. To investigate early events in adipocyte development, we have focused on the transcriptional activation of the LPL gene. For this purpose, we have cloned and fused different parts of intragenic and flanking sequences with a chloramphenicol acetyltransferase reporter gene. Transient transfection experiments and DNase I hypersensitivity assays indicate that several positive as well as negative elements contribute to transcriptional regulation of the LPL gene. When reporter gene constructs were stably introduced into preadipocytes, we were able to monitor and compare the activation patterns of different promoter deletion mutants at selected time points representing the process of adipocyte development. We could delimit two cis-regulatory elements important for gradual activation of the ...

1992-10-01

463

(/sup 14/C)sucrose uptake and labeling of starch in developing grains of normal segl barley

Adenine DNA glycosylase catalyzes the glycolytic removal of adenine from the promutagenic A {center_dot} oxoG base pair in DNA. The general features of DNA recognition by an adenine DNA glycosylase, Bacillus stearothermophilus MutY, have previously been revealed via the X-ray structure of a catalytically inactive mutant protein bound to an A:oxoG-containing DNA duplex. Although the structure revealed the substrate adenine to be, as expected, extruded from the DNA helix and inserted into an extrahelical active site pocket on the enzyme, the substrate adenine engaged in no direct contacts with active site residues. This feature was paradoxical, because other glycosylases have been observed to engage their substrates primarily through direct contacts. The lack of direct contacts in the case of MutY suggested that either MutY uses a distinctive logic for substrate recognition or that the X-ray structure had captured a noncatalytically competent state in lesion ...

2010-01-14

464

Local chromatin structure of heterochromatin regulates repeatedDNA stability, nucleolus structure, and genome integrity

Previous work showed that the segl mutant of barley (Hordeum vulgare o Betzes) did not differ from normal Betzes in plant growth, photosynthesis, or fertility, but it produced only shrunken seeds regardless of pollen source. To determine whether defects in sucrose uptake or starch synthesis resulted in the shrunken condition, developing grains of Betzes and segl were cultured in (/sup 14/C)sucrose solutions after slicing transversely to expose the endosperm cavity and free space. In both young grains (before genotypes differed in dry weight) and older grains (17 days after anthesis, when segl grains were smaller than Betzes), sucrose uptake and starch synthesis were similar in both genotypes on a dry weight basis. To determine if sucrose was hydrolyzed during uptake, spikes of Betzes and segl were allowed to take up (fructose-U-/sup 14/C)sucrose 14 days after anthesis and the radioactivity of endosperm sugars was examined during 3 hours of incubation. Whereas less ...

1984-01-01

465

Upflow anaerobic sludge reactors for the treatment of combined industrial effluent in subtropical conditions: a comparison between UASB and UASF reactors

Heterochromatin constitutes a significant portion of the genome in higher eukaryotes; approximately 30% in Drosophila and human. Heterochromatin contains a high repeat DNA content and a low density of protein-encoding genes. In contrast, euchromatin is composed mostly of unique sequences and contains the majority of single-copy genes. Genetic and cytological studies demonstrated that heterochromatin exhibits regulatory roles in chromosome organization, centromere function and telomere protection. As an epigenetically regulated structure, heterochromatin formation is not defined by any DNA sequence consensus. Heterochromatin is characterized by its association with nucleosomes containing methylated-lysine 9 of histone H3 (H3K9me), heterochromatin protein 1 (HP1) that binds H3K9me, and Su(var)3-9, which methylates H3K9 and binds HP1. Heterochromatin formation and functions are influenced by HP1, Su(var)3-9, and the RNA interference (RNAi) pathway. My thesis project investigates how ...

2007-05-05

466

Toxicity of N-substituted aromatics to acetoclastic methanogenic activity in granular sludge

The performance of anaerobic biological process is heavily process conditions dependent. In this study, an attempt has been made to investigate the influence of process conditions like temperature, sludge age and hydraulic retention time (HRT) on the efficiency of an upflow anaerobic sludge blanket (UASB) reactor and upflow anaerobic sludge filter (UASF) to treat combined industrial wastewater. Reactors were operated at easing ambient temperatures (38, 30, 20 and 14 deg. C) and correspondingly increasing sludge ages (60, 90, 120 and 150 days). At temperature 38 deg. C and sludge age of 60 days, UASF showed better performance than VASE reactor. This mainly due to the enhanced filtration through well-graded sand filter and fairly good biological activity in UASF. At this stage, lack of sludge granulation in VASE reactor resulted in poor biological activity; hence, relatively poor performance. At temperatures 30 and 20 deg. C with sludge ages of 90 and 120 days, respectively, UASB gave ...

2004-06-07

467

Nonphotochemical Hole-Burning Studies of Energy Transfer Dynamics in Antenna Complexes of Photosynthetic Bacteria

N-substituted aromatics are important priority pollutants entering the environment primarily through anthropogenic activities associated associated with the industrial production of dyes, explosives, pestides, and pharmaceuticals. Anaerobic treatment of wastewaters discharged by these industries could potentially be problematical as a result of the high toxicity of N-substituted aromatics. The objective of this study was to examine the structure-toxicity relationship of N-substituted aromatic compounds to acetoclastic methanogenic bacteria. The toxicity was assayed to serum flasks by measuring methane production in granular sludge. Unacclimated cultures were used to minimize the biotransformation of the toxic organic chemicals during the test. The nature and the degree of the aromatic substitution were observed to have a profound effect on the toxicity of the test compound. Nitroaromatic compounds were, on the average, over 500-fold more toxic than their ...

1995-11-01

468

Microbial community analysis of ambient temperature anaerobic digesters

This thesis contains the candidate's original work on excitonic structure and energy transfer dynamics of two bacterial antenna complexes as studied using spectral hole-burning spectroscopy. The general introduction is divided into two chapters (1 and 2). Chapter 1 provides background material on photosynthesis and bacterial antenna complexes with emphasis on the two bacterial antenna systems related to the thesis research. Chapter 2 reviews the underlying principles and mechanism of persistent nonphotochemical hole-burning (NPHB) spectroscopy. Relevant energy transfer theories are also discussed. Chapters 3 and 4 are papers by the candidate that have been published. Chapter 3 describes the application of NPHB spectroscopy to the Fenna-Matthews-Olson (FMO) complex from the green sulfur bacterium Prosthecochloris aestuarii; emphasis is on determination of the low energy vibrational structure that is important for understanding the energy transfer process associated within three ...

2002-06-27

469

Low-head air stripper treats oil tanker ballast water

This paper reported on a study in which designs for Chinese and Indian fixed-dome anaerobic digesters were modified in an effort to produce smaller and more affordable digesters. While these types of systems are common in tropical regions of developing countries, they have not been used in colder climates because of the low biogas yield during the winter months. Although there is evidence that sufficient biogas production can be maintained in colder temperatures through design and operational changes, there is a lack of knowledge about the seasonal changes in the composition of the microbial communities in ambient temperature digesters. More knowledge is needed to design and operate systems for maximum biogas yield in temperate climates. The purpose of this study was to cultivate a microbial community that maximizes biogas production at psychrophilic temperatures. The study was conducted on a 300 gallon experimental anaerobic digester on the campus of Ohio State University. ...

2010-07-01

470

Irradiation of Microbes from Spent Nuclear Fuel Storage Pool Environments

Prototype tests conducted during the winter of 1989/90 have successfully demonstrated an economical design for air stripping volatile hydrocarbons from oily tanker ballast water. The prototype air stripper, developed for Alyeska's Ballast Water Treatment (BWT) facility in Valdez, Alaska, ran continuously for three months with an average removal of 88% of the incoming volatile organics. Initially designed to remove oil and grease compounds from tanker ballast water, the BWT system has been upgraded to a three-step process to comply with new, stringent regulations. The BWT biological oxidation process enhances the growth of bacteria present in the incoming ballast water through nutrient addition, aeration, and recirculation within a complete-mixed bioreactor. The average removal of BETX is over 95%, however, occassional upsets required the placement of a polishing air stripper downstream of the aeration tanks. Packed-tower air stripping was investigated but ...

1992-02-01

471

Identification of unusual Campylobacter-like isolates from poultry products as Helicobacter pullorum

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 ...

1999-09-03

472

DEFF Research Database (Denmark)

Twenty-six unclassified Campylobacter-like strains previously isolated from 15 chicken carcasses and caecal contents, together with two more strains isolated from chicken faeces on a different occasion, were identified as Helicobacter pullorum using various phenotypic identification methods. API Campy identification kits and a 16-test identification scheme developed for campylobacters failed to identify these bacteria, or identified them as Campylobacter spp. Eighteen strains (including the two isolated on a different occasion) were chosen for examination using a more comprehensive probabilistic identification scheme. Using this method, 14 of the 18 strains were identified as H. pullorum with ID scores > 95%; two strains were also identified as H. pullorum with lower ID scores. Of the remaining two strains, one was not identified with this scheme and the other was misidentified to the H, acinonyx pylori complex. Whole cell protein profiling by SDS-PAGE confirmed ...

1998-01-01

473

Genomic analysis of the symbiotic marine crenarchaeon, Cenarchaeumsymbiosum

Evaluation of potential hydrocarbon sources in lacustrine facies of Newark Supergroup, eastern United States

Crenarchaea are ubiquitous and abundant microbial constituents of soils, sediments, lakes and ocean waters, yet relatively little is known about their fundamental evolutionary, ecological, and physiological properties. To better describe the ubiquitous nonthermophilic Crenarchaea, we analyzed the genome sequence of one representative, the uncultivated sponge symbiont, Cenarchaeum symbiosum. C. symbiosum genotypes coinhabiting the same host partitioned into two dominant populations, corresponding to previously described a- and b-type ribosomal RNA variants. Although synthetic, overlapping a- and b-type ribotypes harbored significant genetic variability. A single tiling path comprising the dominant a-type genotype was assembled, and used to explore the biological properties of C. symbiosum and its planktonic relatives. Out of a total of 2,066 predicted open reading frames, 36% were more highly conserved with other Archaea. The remainder partitioned between bacteria ...

2006-06-24

474

Efficient natural defense mechanisms against Listeria monocytogenes in T and B cell-deficient allogeneic bone marrow radiation chimeras. Preactivated macrophages are the main effector cells in an early phase after bone marrow transfer

Lacustrine rocks are a significant component of many rift-valley sequences. Comparisons of both active and ancient rift valleys indicate that the lacustrine facies are commonly rich in organic matter and may be important sources for oil. For example, Holocene sediments in Lake Tanganyika and Cretaceous lacustrine rocks in west Africa contain as much as 12% and 20% TOC, respectively. The Newark Supergroup contains abundant lacustrine rocks. The widespread occurrence of black shales, the general similarity to known organically rich rift systems, and a few isolated geochemical analyses have caused some speculation about the potential of the Newark Supergroup to be an effective source of oil and gas. Sufficient geochemical analyses are available from lacustrine rocks in the Newark, Connecticut, and Deep River basins to evaluate their potential as hydrocarbon sources. In general, both the quantity and quality of organic matter in these rocks are less than that required for potential source ...

1985-02-01

475

Effect of temperature on the development of Steinernema carpocapsae and Steinernema feltiae (Nematoda: Rhabditida) in liquid culture.

Radiation chimeras in the early phase after bone marrow transplantation are a good model to study the efficiency of the body's nonspecific defense system represented by macrophages (M phi), polymorphonuclear cells (PMN), and NK cells. These cell types are present in large numbers in spleen and liver at that time, whereas the specific immune system represented by T and B cells is functionally deficient. We previously reported enhanced activities in vitro of M phi (and PMN) from recipient animals in an early phase after allogeneic bone marrow transfer. We here demonstrate that these activities result in enhanced spontaneous resistance against Listeria monocytogenes in vivo: CFU of L. monocytogenes in spleen and liver 48 h after infection were about 1 or 2 to 4 log steps less than in untreated control mice of donor or host haplotype. This enhanced resistance decreased over the 4-mo period after marrow transfer. Preactivated M phi were identified as the most important effector cells. ...

476

Does tea tree oil have a place in the topical treatment of burns?

For commercial use of the entomopathogenic nematodes Steinernema carpocapsae and Steinernema feltiae in biological control of insect pests, they are produced in liquid culture on artificial media pre-incubated with their symbiotic bacteria Xenorhabdus nematophila and Xenorhabdus bovienii, respectively. After 1 day of the bacterial culture, nematode dauer juveniles (DJs) are inoculated, which recover development. The adult nematodes produce DJ offspring, which are harvested and can be sprayed. This study determined optimal temperatures to obtain high DJ progeny within a short process time. Temperatures assessed were 23 degrees C, 25 degrees C, 27 degrees C, and 29 degrees C for S. carpocapsae and 20 degrees C, 23 degrees C, 25 degrees C, and 27 degrees C for S. feltiae. The recovery of inoculated DJs was hardly affected and was reduced only in S. carpocapsae at 29 degrees C. The fecundity (eggs in uterus) in S. carpocapsae reached a maximum at 27 degrees C; whereas, ...

2009-05-20

477

Development of a microbiological ammonium to nitrate recycling bioreactor for space capsules

Burnaid is a sorbalene-based cream containing 40 mg/g of tea tree oil and 1 mg/g of triclosan. This investigation was carried out to determine the effect of Burnaid, a commercial tea tree oil preparation, against Enterococcus faecalis (ATCC29212), Staphylococcus aureus (ATCC29213), Escherichia coli (ATCC25922), and Pseudomonas aeruginosa (ATCC27853), with the activity of the base product in the commercial preparation. The organisms were suspended in sterile saline (0.5 McFarland Standard) and inoculated onto horse blood agar (E. faecalis and S. aureus) or Mueller-Hinton agar (E. coli and P. aeruginosa). One hundred microliters of Burnaid unsterilized, Burnaid sterilized and the base product (Tinasolve) were placed in duplicate in wells cut into the agar plates. Sterility and inactivation cultures were also performed on the samples. None of the samples were found to be contaminated with bacteria prior to testing. Only S. aureus and E. coli showed zones of growth ...

1997-06-01

478

A field demonstration of the microbial treatment of sour produced water

Since 1988, the Expertise group of Molecular and Cellular Biology (MCB) is an important partner in the development of the Micro-Ecological Life Support System Alternative (MELiSSA). The MELiSSA was designed to allow a small crew to survive on an Antarctic, lunar or Mars outpost, and is a joint research project currently fostered by the European Space Agency, ESA. The MELiSSA functions through a series of five interconnected compartments, of which four are microbial bioreactors and was engineered to degrade organic waste, regenerate the outpost's atmosphere and water, and provide the crew with an additional vegetarian diet. The bioreactor of the third compartment provides the edible cyanobacteria and plants of the fourth compartment with nitrate instead of ammonium as a source of nitrogen. The two bacteria responsible for the biological transformation of ammonium to nitrate (nitrification) are Nitrosomonas europaea and Nitrobacter winogradskyi. Since all ...

2009-09-01

479

Nature and distribution of mucosal lesions associated with enteropathogenic and enterohemorrhagic Escherichia coli in piglets and the role of plasmid-mediated factors.

The potential for detoxification and deodorization of sulfide-laden water (sour water) by microbial treatment was evaluated at a petroleum production site under field conditions. A sulfide-tolerant strain of the chemautotroph and facultative anaerobe, Thiobacillus denitrificans, was introduced into an oil-skimming pit of the Amoco Production Company LACT 10 Unit of the Salt Creek Field, Wyoming. Field-produced water enters this pit from the oil/water separation treatment train at an average flowrate of 5,000 bbl/D (795 m{sup 3}/D) with a potential maximum of 98,000 bbl/D (15,580 m{sup 3}/D). Water conditions at the pit inlet are 4,800 mg/l TDS, 100 mg/l sulfide, pH 7.8, and 107{degrees}F. To this water an aqueous solution of ammonium nitrate and diphosphorous pentoxide was added to provide required nutrients for the bacteria. The first 20% of the pit was aerated to a maximum depth of 5 ft (1.5 m) to facilitate the aerobic oxidation of sulfide. No provisions for pH ...

1995-12-31

480

Microbial remediation of soil pollution from ore mining. Part 3: Cyanide removal and biosorption of heavy metals in mining and processing water; Untersuchungen zur mikrobiellen Sicherung von Erzbergbaualtlasten. Teilvorhaben 3: Cyanidabbau und Biosorption von Schwermetallen in Abwaessern aus Erzbergbau- und Aufbereitungsbetrieben. Abschlussbericht

Bacterial attachment-effacement (att-eff) is emerging as an important virulence characteristic common to both enteropathogenic Escherichia coli (EPEC) and enterohemorrhagic E. coli (EHEC). The contribution of the plasmid-encoded EPEC adherence factor to the production of mucosal lesions and diarrhea was investigated in gnotobiotic piglets. Bacterial att-aff in the intestinal mucosa of piglets infected with plasmid-cured EPEC strain E2348/69 (O127) was indistinguishable from that in piglets infected with the parent strain, but the distribution of lesions was different; it occurred in the small intestines of 6 of 7 piglets infected with the parent strain compared with only 2 of 11 (P = 0.006) infected with the plasmid-cured strain. Plasmid-encoded factors in EPEC and EHEC strains did not appear to contribute to bacterial competition with normal gut microflora. Of 13 strains belonging to five EPEC serogroups, O55, O142, O26, O119, and O111, 3 fulfilled the criteria for EHEC (2 O26 and 1 ...

1989-04-01

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481

Corrosion behaviour of non-ferrous metals in sea water

1. Cyanide degradation: Of the cyanide- and thiocyanate-degrading bacteria, Burkholderia cepacia and Pseudomonas spec. were the most effective. 2. Biosorption: Of the isolates suited for biosorption of heavy metals, 597-A (non-identifiable) and 597-A2 (Aspergillus fumigatis) had the biggest potential. The sorption capacity of the fungi for metals varied with the C source used for their growth: apple juice > molasses > glucose. The fungi are not cyanide-sensitive and can even degrade cyanide. Living biomass had better metal sorption efficiencies than dead mycelium. The biosorption rates in waste water were usually higher than in broth. Depending on the metal composition and concentrations and on the exposure time and volume of the mycelia, up to 85 % of the initial concentration was removed from the liquid phase. The capacity of different biomasses for the sorption of metal mixtures was between 65 and 80 mg/g of dry matter depending on the experimental ...

1999-12-01

482

Biogeochemistry of the compost bioreactor components of a composite acid mine drainage passive remediation system

The most typical kinds of corrosion of brasses are selective corrosion (dezincification) and stress corrosion. Prevention against these kinds of corrosion lies in application of arsenic alloy addition and appropriate heat treatment removing internal stresses as well as in maintaining the arsenic and phosphorus contents on a proper level. The most typical corrosion of cupronickels is the local corrosion. Selective corrosion occurs less often and corrosion cracking caused by stress corrosion in sea water does not usually occur. Crevice corrosion is found especially in places of an heterogeneous oxidation of the surface under inorganic deposits or under bio-film. Common corrosive phenomena for brasses and cupronickels are the effects caused by sea water flow and most often the impingement attack. Alloy additions improve resistance to the action of intensive sea water flow but situation in this field requires further improvement, especially if the cheaper kinds of alloys are concerned. ...

2004-07-01

483

Review of Constructed Subsurface Flow vs. Surface Flow Wetlands

The compost bioreactor ('anaerobic cell') components of three composite passive remediation systems constructed to treat acid mine drainage (AMD) at the former Wheal Jane tin mine, Cornwall, UK were studied over a period of 16 months. While there was some amelioration of the preprocessed AMD in each of the three compost bioreactors, as evidenced by pH increase and decrease in metal concentrations, only one of the cells showed effective removal of the two dominant heavy metals (iron and zinc) present. With two of the compost bioreactors, concentrations of soluble (ferrous) iron draining the cells were significantly greater than those entering the reactors, indicating that there was net mobilisation (by reductive dissolution) of colloidal and/or solid-phase ferric iron compounds within the cells. Soluble sulfide was also detected in waters draining all three compost bioreactors which was rapidly oxidised, in contrast to ferrous iron. Oxidation and hydrolysis of iron, together with ...

2005-02-01

484

Phytoremediation of Ionic and Methyl Mercury P

The purpose of this document is to use existing documentation to review the effectiveness of subsurface flow and surface flow constructed wetlands in treating wastewater and to demonstrate the viability of treating effluent from Savannah River Site outfalls H-02 and H-04 with a subsurface flow constructed wetland to lower copper, lead and zinc concentrations to within National Pollutant Discharge Elimination System (NPDES) Permit limits. Constructed treatment wetlands are engineered systems that have been designed and constructed to use the natural functions of wetlands for wastewater treatment. Constructed wetlands have significantly lower total lifetime costs and often lower capital costs than conventional treatment systems. The two main types of constructed wetlands are surface flow and subsurface flow. In surface flow constructed wetlands, water flows above ground. Subsurface flow constructed wetlands are designed to keep the water level below the top of the rock or gravel media, ...

2004-09-01

485