bluuebunny/crossref_metadata_2025 huggingface dataset:
Serviceability design factors for wind-sensitive structures
Authors: Pozos-Estrada A. , Hong H. P. , Galsworthy J. K.
Published: May 2010

Wind-sensitive buildings can experience excessive vibrations that cause discomfort and interruption of the activities of the inhabitants of the buildings. To ensure the desired serviceability, codes, standards, and their commentaries have proposed perception curves that limit the expected (or mean) peak acceleration or standard deviation of the acceleration of the buildings. These perception curves are developed based on perceived vibration alone and do not consider the uncertainty in structural dynamic characteristics (i.e., natural frequency of vibration and ratio of damping) and loads such as the wind loading. Therefore, the annual probability that the perception curve is not exceeded for a building whose design is based on the perception curve is unknown. In this study, serviceability design factors are calibrated for selected targeted annual probability of perception levels by considering the uncertainty in the structural dynamic characteristics, wind characteristics, as well as in the human perception of motion. These serviceability design factors are to be used with the estimated mean peak acceleration caused by along-wind and cross-wind excitations given in the commentaries of the current National building code of Canada. The use of calibrated serviceability design factors for design checking is illustrated with a numerical example.
Analysis of rheological properties of rubberized binders containing warm asphalt additives
Authors: Akisetty Chandra K. , Gandhi Tejash , Lee Soon-Jae , Amirkhanian Serji N.
Published: May 2010

The main objective of using warm mix asphalt (WMA) is to reduce emissions and improve the workability by lowering the mixing and compaction temperatures of asphalt mixes through different mechanisms. Since warm asphalt is a relatively new technology, not much research has been conducted on various mix compositions. While some of the concerns about WMA have been addressed, the interaction of warm mix additives with modified binders, especially crumb rubber modified (CRM) binder, is not known in great detail. This paper presents the data on rheological tests conducted on rubberized binders containing warm asphalt additives. Binders from five different sources were modified using 10% crumb rubber by weight of the virgin binders. Two of the available warm asphalt technologies, Aspha-min® and Sasobit®, were used to produce the warm asphalt binders. From the tests, it was observed that the addition of the warm asphalt additives significantly reduce the permanent deformation of the binders, increase the viscosity at 60 °C and the complex modulus, G*, and decrease the phase angle, δ, at high frequencies and low temperatures compared with the CRM binders.
Evaluation of the biodegradation feasibility of antibiotics by three bacteria involving glutathione S-transferasesA paper submitted to the Journal of Environmental Engineering and Science.
Authors: Park Hyeyoung , Choung Youn-Kyoo
Published: May 2010

Swine wastewater is not easy to dispose of in usual biological wastewater treatment plants. One reason is that some antibiotics are not easily degradable in the normal treatment system and suppress or inhibit microorganisms in the treatment system. Specifically tetracycline, sulfathiazole, and ampicillin have been widely used as antibiotics in pig feed. For treating disposal and spillage of these antibiotics biologically, a special enzyme based method is needed. Detoxifying enzymes caused the antibiotics to be bio-converted in this experiment and degraded them in this biological experiment. The glutathione S-transferases (GSTs) catalyzed the conjugation of glutathione (GSH) to a number of hydrophobic electrophilic substrates. In this study, we hypothesized that the microorganisms with GSTs degraded the representative manure antibiotics. The initial concentrations of tetracycline, sulfathiazole, and ampicillin were 100 mg/L, 100 mg/L, and 50 mg/L, respectively. These concentrations of antibiotics in pig feed are typical levels. Evaluation of the biodegradation feasibility of antibiotics was carried out by three bacteria possessing glutathione S-transferases under the strong concentration of antibiotics (standards for livestock pharmaceuticals in pig feed).
Polymorphonuclear neutrophil-mediated antibody-dependent cell cytotoxicity of herpesvirus-infected cells: ultrastructural studies
Authors: Grewal A. S. , Carpio M. , Babiuk L. A.
Published: May 2010

Bovine polymorphonuclear neutrophils (PMN) can mediate antibody-dependent cell cytotoxicity (ADCC) of herpes virus-infected cells. Since cytotoxicity occurs only in the presence of PMN and specific antiviral antibody, but not until viral membrane antigens are expressed on the target cell, it is concluded that antibody must recognize viral membrane antigens before cytotoxicity can occur. Cytotoxicity also requires very close contact between the target cell and the PMN cell. These interactions occur as early as 1 h after incubating antibody, infected cells, and PMN, but the actual lysis and release of intracellular components occur over an extended period. It was assumed that degranulation was not involved in the initiation of cytotoxicity, but was involved in the final stage of destruction. The mechanism of lysis is proposed to involve the interaction of PMN membranes with target cell membranes with subsequent reorganization and activation of the PMN plasma membrane at points of contact with the target cell. This results in possible production of transmembrane channels which allows for the release of target cell contents.
Virus isolations from mosquitoes in southern Ontario, 1976 and 1977
Authors: Thorsen J. , Artsob H. , Spence L. , Surgeoner G. , Helson B. , Wright R.
Published: May 2010

Following the 1975 epidemic of St. Louis encephalitis (SLE) in Ontario, programs were instituted to monitor virus activity in mosquito populations during 1976 and 1977. Mosquitoes were trapped with CDC light traps and CO2 cone traps, pooled by species, and tested for virus by intracerebral inoculation of suckling mice. In 1976, 51 175 mosquitoes were tested. SLE virus was isolated from two mixed pools of Culex pipiens – C. restuans mosquitoes. Five isolations of California serogroup viruses were made. Three of these were trivittatus virus, which has not been demonstrated previously in Canada, and the other two were snowshoe hare virus. Other viruses isolated in 1976 were a virus antigenically identical to the virus of infectious bursal disease of chickens and 34 Flanders viruses. In 1977, 34 428 mosquitoes were tested. Flanders virus was isolated most frequently, from pools of mixed C. pipiens – C. restuans mosquitoes. The only other isolate was a Bunyamwera group virus, Cache Valley virus. This virus has not been reported previously in Ontario.
Uptake of D-glucose and L-proline by oligotrophic and heterotrophic marine bacteria
Authors: Akagi Y. , Taga N.
Published: May 2010

The transport systems of the oligotrophic bacterium 486 for D-glucose and L-proline have been compared with those of the heterotrophic bacterium RP-303. Kinetic studies demonstrated that the rates of D-glucose and L-proline uptake by the two organisms were saturable processes. The apparent Km values of strain 486 for D-glucose and L-proline were 13.0 μM and 0.2 μM, respectively, whereas those of strain RP-303 were 3.2 μM for D-glucose and 1.8 μM for L-proline. Competition studies indicated that the D-glucose transport system of each bacterium was highly specific for D-glucose. The L-proline transport system of the oligotrophic bacterium 486 had a broad specificity, whereas that of the heterotrophic bacterium RP-303 had a narrow one.
Présence de Pseudomonas maltophilia dans la rhizosphère de quelques plantes cultivées
Authors: Debette J. , Blondeau R.
Published: May 2010

Pseudomonas maltophilia has been identified in the rhizosphere of several cultured plants: cabbage, rape, mustard, corn, beet. In comparison with nonrhizospheric soil, all the rhizospheric samples analysed contain more of this Pseudomonas and the most important stimulation is supplied by cruciferous plants. The possible relation with greater amounts of sulphur-containing amino acids in root secretion is suggested.
Influence de l'intensité lumineuse sur la teneur en bactériochlorophylle et sur la croissance de sulfobactéries phototrophes marines
Authors: Matheron Robert , Baulaigue Renée
Published: May 2010

Eight strains of Chromatiaceae isolated from marine sediments are cultivated under light intensities of 50–5000 lx. A decrease in the light intensity brings about an increase in the specific bacteriochlorophyll content and also in the length of development. In certain strains, the increase in pigment contents partly compensates for the loss in light intensity, up to the maximum concentration of bacteriochlorophyll. This mechanism is only a physiological compatibility which ensures the survival of these organisms under feeble light intensities.
Interaction of lectins with Neisseria gonorrhoeae
Authors: Allen Peter Z. , Connelly Mark C. , Apicella Michael A.
Published: May 2010

Fifty-four strains of Neisseria gonorrhoeae were examined for their ability to be agglutinated by various lectins. Wheat germ agglutinin, ricin, soybean lectin, and peanut agglutinin agglutinated all strains tested. Dolichos biflorus, Sophora japonica, Maclura pomifera, Ulex europaeus, Lens culinaris, Canavalia ensiformis, Phaseolus lunatus, and Bandeiraea simplicifolia BS I and BS II lectins either failed to agglutinate or agglutinated some strains but not others. Agglutination of gonococci by wheat germ agglutinin, ricin, and soybean lectin is sugar specific and most effectively inhibited by ligands known to interact with lectin combining sites. Lectin reactive groupings appear to be independent of antigenic determinants conferring Gc serogroup specificity. Interactions with wheat germ agglutinin and ricin suggest the occurrence of multiple β-linked N-acetyl-D-glucosamine (D-GlcNAc) and β-D-galactosyl (β-D-Gal) units as common structural features of gonococcal cell envelope polysaccharide. Interactions with soybean agglutinin, peanut agglutinin, and Dolichos biflorus lectins suggest that α-N-acetyl-D-galactosamine (α-D-GalNAc) units and β-D-Gal linked to GalNAc and (or) GlcNAc may also occur as structural features of the polysaccharide components of the cell envelope of some gonococci.
Degradation of parathion in culture by microorganisms found in cranberry bogs
Authors: Gorder Greg W. , Lichtenstein E. Paul
Published: May 2010

Oxygen concentration and different carbon sources drastically altered parathion degradation in culture media inoculated with microorganisms from Wisconsin cranberry (Vaccinium macrocarpon Ait.) growing soils. These microorganisms also grew in basal salts media utilizing parathion as the sole carbon source. 14CO2 was produced only from [phenyl-14C]parathion, whereas [ethyl-14C]parathion-derived radiocarbon remained in the stale media of the soil-free cultures. Addition of 0.05% glucose to basal salts medium inhibited [phenyl-14C]parathion degradation, whereas the addition of 0.05% yeast extract to basal salts medium also inhibited microbiological degradation of the insecticide to 14CO2, but to a lesser extent. Aminoparathion and aminoparaoxon were formed only in basal salts medium with 0.05% yeast extract. Aerobic cultures produced more 14CO2 and less aminoparathion from [phenyl-14C]parathion than did anaerobic cultures. Aminoparathion was more abundant in cultures with inocula obtained from the 18- to 23-cm soil layer than with culture inocula obtained from the 0- to 5-cm soil layer under both aerobic and anaerobic conditions.
An increase in nitrogen content of Setaria italica and Zea mays inoculated with Azospirillum
Authors: Nur Israel , Okon Yaacov , Henis Yigal
Published: May 2010

Bacteria belonging to the genus Azospirillum isolated from Cynodon dactylon roots in Israel were compared with Azospirillum brasilense from Brazil and California for their ability to fix nitrogen in association with grasses under greenhouse conditions. The plants were grown in a system which avoided cross inoculation from the inoculated soil to the control, while maintaining the natural soil microflora and humidity level in the soil close to field capacity. The organisms tested significantly increased the dry weight of Zea mays and Setaria italica leaves, the total nitrogen content of these leaves (as measured by the Kjeldahl method), and supported acetylene reduction in intact nonsterile systems as compared with the noninoculated controls. Ethylene production in intact systems could be detected after 6 h and was linear for 72 h, providing a constant soil temperature (28–32 °C) was maintained.
Parasporal crystals produced by oligosporogenous mutants of Bacillus thuringiensis (Spo− Cr+)
Authors: Johnson Donovan E. , Niezgodski Debra M. , Twaddle George M.
Published: May 2010

Six oligosporogenic (Spo−) mutant strains of Bacillus thuringiensis were selected from survivors of treatment with N-methyl-N′-nitro-N-nitrosoguanidine. Each strain was blocked at or before stage II of spore development, but all produced typical bipyramidal-shaped crystalline inclusion bodies. Toxicity of the parasporal endotoxin isolated from the mutant strains was assayed by an in vitro technique using cultured insect cells, and was comparable with that of normal wild-type parasporal protein. Multiple parasporal inclusion bodies per cell were often produced, and smaller embedded particles were numerous and distinct.
Experimental pathogenicity of Vibrio parahaemolyticus for the schistosome-bearing snail Biomphalaria glabrata
Authors: Ducklow Hugh W. , Tarraza Jr. Hector M. , Mitchell Ralph
Published: May 2010

The bacterium Vibrio parahaemolyticus was found to be pathogenic for the schistosome intermediate host Biomphalaria glabrata (Say). When administered topically, a nonenteritis- associated strain of the bacterium had an LD50 (median lethal dose) of 6.8 × 107 cells per snail. A 5% trichloroacetic acid (TCA) extract from V. parahaemolyticus was found to kill B. glabrata. Sublethal effects of V. parahaemolyticus include shell deterioration and increased heart rate. Both albino aquarium populations and naturally occurring Puerto Rican wild populations of B. glabrata are susceptible to V. parahaemolyticus. This bacterium provides a useful model for the study of pathogens and biological control of schistosome vector snails, since it causes significant mortality and is recognized as a pathogen of other invertebrates.
Mechanism of the temperature protective effect of salts on Staphylococcus aureus
Authors: Hurst A. , Hughes A. , Pontefract R.
Published: May 2010

In the previous paper we reported that the maximum temperature for growth of Staphylococcus aureus was about 2 °C higher in media supplemented with NaCl. We now show that MgCl2 was the most effective protectant at 0.4 M. NaCl and KCl were as effective as MgCl2 when tested at 1 M. NH4Cl was less effective at all concentrations and LiCl was not protective. Sucrose and glucose (1 M) gave about half the biomass of 1 M NaCl. Glycerol, Na2SO4, NaNO2, NaNO3, and CH3COONa were not protective. Protection is probably due to the nonpenetrating solute (sucrose) or the nonpenetrating Cl− anion. Mg2+ had an effect additional to that attributable to Cl− because MgSO4 and to a slight extent (CH3COO)2Mg were protective. The morphology of the cells grown at 45 °C in 1 M NaCl was abnormal: septation became irregular, cell walls were thickened, and the cells occurred in irregularly sized clumps surrounded by capsular material.
Rabbit erythrocyte band 3: a receptor for staphylococcal alpha toxin
Authors: Maharaj Indar , Fackrell Hugh B.
Published: May 2010

Enzymes known to specifically cleave the band 3 component of the rabbit erythrocyte membrane were found to reduce both the hemolytic sensitivity to and the binding of the alpha toxin of Staphylococcus aureus. Lectins which bind to band 3 also inhibited the toxin. Lectins which do not bind to band 3 have no effect. Purified band 3, isolated by affinity chromatography on a concanavalin A column, was homogeneous by polyacrylamide gel electrophoresis, had a molecular weight of 100 000, and inhibited the hemolytic activity of alpha toxin. Antibodies to the toxin–toxoid receptor were serologically indistinguishable from antiband 3.
Procedures and equipment for staining large numbers of plant root samples for endomycorrhizal assay
Authors: Kormanik Paul P. , Bryan W. Craig , Schultz Richard C.
Published: May 2010

A simplified method of clearing and staining large numbers of plant roots for vesicular–arbuscular (VA) mycorrhizal assay is presented. Equipment needed for handling multiple samples is described, and two formulations for the different chemical solutions are presented. Because one formulation contains phenol, its use should be limited to basic studies for which adequate laboratory exhaust hoods are available and great clarity of fungal structures is required. The second staining formulation, utilizing lactic acid instead of phenol, is less toxic, requires less elaborate laboratory facilities, and has proven to be completely satisfactory for VA assays.
Semipermanent microscope slides of microfungi using a sticky tape technique
Authors: Flegel T. W.
Published: May 2010

A technique is described for making semipermanent microscope slides of fungi using sticky tape. After being touched to a fungal colony, a modified segment of sticky tape is touched to ethyl alcohol and then immersed in a 50% glycerine solution containing cotton blue stain. Finally, it is transferred (sticky side up) to a microscope slide, covered with a cover glass, and sealed.
Identification of Pseudomonas aeruginosa with the API-20E system
Authors: Amato Sandra , Vanik Janet , Kocka Frank E.
Published: May 2010

The API-20E multitest system was found to be capable of identifying Pseudomonas aeruginosa isolates at least to the level of the Pseudomonas fluorescens group within 18 h at 35 °C. Additional tests, such as the acetamide reaction, growth at 42 °C, and the oxidative (OF) glucose test, assisted in the speciation of P. aeruginosa.
Interaction of concanavalin A with herpes simplex virus infected cells
Authors: Adler Richard , Paquette Carol I.
Published: May 2010

Incubation of herpes simplex virus (HSV) infected cells with concanavalin A (Con A) interferes with binding of the Fc portion of antibody. In addition, the lectin inhibits complement mediated cytolysis, probably by interference with antibody binding. These results suggest that binding sites of both Fc and HSV antibody contain residues which attract Con A.
Sporulation and regulation of homoserine dehydrogenase in Bacillus subtilis
Authors: Yeggy James P. , Stahly Donald P.
Published: May 2010

Homoserine dehydrogenase in dialyzed cell extracts of Bacillus subtilis 168 was studied, particularly with regard to inhibition, repression, and level of activity as a function of stage of development (growth and sporulation). It was assayed in the "forward direction" using L-aspartic semialdehyde and NADPH as substrates. Of the potential inhibitors tested, only cysteine and NADP were found to be effective. Both L- and D-cysteine were equally effective. Therefore, the physiological significance of cysteine as an inhibitor is somewhat questionable. Amino acids involved in repression of homoserine dehydrogenase included methionine, isoleucine, possibly threonine, and one or more unidentified components of Casamino acids. The specific activity of homoserine dehydrogenase was highest during the exponential phase of growth and declined steadily during the stationary phase of growth. The low specific activity during late sporulation may favor preferential funneling of L-aspartic semialdehyde into the lysine pathway, where it is needed for synthesis of large amounts of dipicolinic acid and diaminopimelic acid.
Differential inactivation of three bacteriophages by acid and alkaline pH used in the membrane adsorption–elution method of virus recovery
Authors: Sabatino Carolyn M. , Maier Siegfried
Published: May 2010

The study was prompted by our inability to concentrate phages by a membrane adsorption method effective for polioviruses. Consequently two coliphages, WPK and T4, and F116 of Pseudomonas aeruginosa were tested for their resistance to acid (pH 5.2–3.2) and alkaline (pH 10–11.5) exposures. Only T4 proved acid resistant, allowing for acid adsorption, and only WPK was sufficiently alkaline resistant to allow for alkaline elution. Thus, the differential susceptibility of various phages precludes the use of the acid membrane adsorption–alkaline elution method as a general method for the concentration of phages from large volumes of water.
Morphological comparison of isolates of Phakopsora pachyrhizi from different areas of the world
Authors: Bonde M. R. , Brown M. F.
Published: May 2010

Isolates of Phakopsora pachyrhizi from Australia, Indian, the Philippines, Taiwan, and Puerto Rico were compared with respect to morphology and development of 'Wayne' soybean. The most extensive comparisons were made between the Puerto Rican and Taiwanese isolates; these were indistinguishable in their prepenetration, penetration, and early colonization phases. Examination of uredia of all isolates by light and scanning electron microscopy (SEM) revealed no differences in uredial morphology. All isolates were indistinguishable with respect to uredospore size, shape, and apparently the number and distribution of uredospore germ pores. The only difference observed was the appearance of germ pores; germ pores of the Puerto Rican isolate were easier to see by means of SEM than those of the four Eastern Hemisphere isolates, suggesting that the Puerto Rican isolate may have thinner germ pore plugs. This difference is not sufficient to consider the isolates as taxonomically distinct.
Genetic analysis of the actinomycin-producing determinants (plasmid) in Streptomyces parvulus using the protoplast fusion technique
Authors: Ochi Kozo , Katz Edward
Published: May 2010

Doubly auxotrophic, actinomycin-producing and nonproducing strains of Streptomyces parvulus were crossed by protoplast fusion. A strong bias toward the act+ character was noted in all recombinant classes obtained. Analysis of four nutritonal markers revealed that they are ordered on a circular linkage map as follows: ura-lys-met-rib-(ura). This sequence resulted in the lowest frequency (2.4–3.4%) of quadruple crossover (QCO) recombinants. Inclusion of the property of actinomycin production in this sequence resulted in a much greater minimum frequency of QCO recombinants (3–4 times higher). Moreover, the location of the act character minimizing the QCO frequency varied from cross to cross despite the fact that fusion of the act− strains did not yield act+ recombinants. It is concluded that actinomycin synthesis is determined (or controlled) by an episomic factor(s).
Serotypes among Neisseria meningitidis serogroups B and C strains isolated in Canada
Authors: Ashton F. E. , Ryan A. , Diena B. B. , MacKenzie A. M. R. , Chan F.
Published: May 2010

Antisera made to prototype serogroup B strains of Neisseria meningitidis were used to serotype, by agar gel double diffusion, 262 meningococcal serogroups B and C strains isolated in Canada. The strains included 93 from patients and 169 from carriers. Serotype 2 was associated with 39 of 75 (52%) of group B strains and 14 of 18 (77.8%) of group C strains isolated from patients. The group B strains were mainly (87.2%) serotype 2b, while the majority (92.2%) of group C strains was serotype 2a. Other serotypes (including a new provisional serotype) represented 25.3 and 5.5% of groups B and C strains, respectively. The new serotype accounted for 13% of the group B strains. Approximately 23% of the strains isolated from patients were nontypable. The distribution of serotype 2, nontype 2 (other serotypes), and nontypable strains isolated from carriers was 2.1, 36.6, and 61.3%, respectively, for group B meningococci and 22.2, 29.6, and 48.2%, respectively, for group C meningococci. Serotype 11 was the most prominent of the strains isolated from carriers. Approximately 7% of all the strains were multiple serotypes. Serotype 2 is an important virulence marker associated with meningococcal groups B and C disease in Canada, with serotypes 2a and 2b being markedly associated with groups C and B meningococcal disease, respectively.
Interaction of lectins from soybean and peanut with rhizobia that nodulate soybean, peanut, or both plants
Authors: Pueppke Steven G. , Freund Tom G. , Schulz Brent C. , Friedman Harvey P.
Published: May 2010

Four of 14 strains of Rhizobium japonicum from soybean nodulated peanut (Arachis hypogaea L. cultivar Jumbo Virginia), and 3 of 8 Rhizobium sp. strains from peanut nodulated soybean (Glycine max (L.) Merr. cultivar Harosoy 63). Cells of three peanut rhizobia bound fluorescent-and radioisotope-labeled soybean lectin. Two of these strains failed to nodulate soybean, and conversely, two peanut strains that nodulated soybean did not bind to soybean lectin. Both culture medium and age had pronounced effects of the number of peanut rhizobia cells that bound fluorescent-labeled soybean lectin. Harosoy 63 soybean root exudates stimulated the growth of peanut rhizobia, but had no consistent influence on the number of cells that bound soybean lectin. Although extracellular soybean lectin receptors were present in culture fluids from each of the peanut rhizobia whose cells bound the lectin, the titer of receptors was greatest for strain 3G4b5. The affinity constants for the adherence of soybean lectin to Rhizobium sp. 3G4b5 cells from cultures of various ages ranged from 4.2 × 106 to 4.9 × 106M−1 and the number of lectin binding sites per cell decreased as cells aged. Cells of the soybean and peanut rhizobia did not bind fluorescent- or radioisotope-labeled peanut lectin. The results indicate that there is no relation ship between the ability of peanut and soybean rhizobia to nodulate the reciprocal host plant and their ability to bind to the lectin of that plant.
Anaerobic co-oxidation of acetate and glucose by Citrobacter intermedius and a species of Pseudomonas
Authors: Brosseau J. D. , Zajic J. E.
Published: May 2010

Analysis of gases evolved when Citrobacter intermedius and a Pseudomonas species are co-cultured on an acetate or glucose – nitrate – mineral salts medium indicates that acetate is anaerobically oxidized to CO2.
Mannose utilization in Escherichia coli requires cyclic AMP but not an exogenous inducer
Authors: Fraser Ann D. E. , Yamazaki Hiroshi
Published: May 2010

It has not been clarified whether the utilization of mannose by Escherichia coli requires adenosine 3′,5′-cyclic monophosphate (cyclic AMP). Using an adenylyl cyclase deficient mutant (CA8306B) and a cyclic AMP receptor protein (CRP) deficient mutant (5333B) we have shown that the utilization of mannose is dependent on the cyclic AMP–CRP complex. 2-Deoxyglucose (DG) is a nonmetabolizable glucose analog specific for the phosphotransferase system (PTS) which transports mannose (termed here PTSM). Growth of CA8306B on glycerol is unaffected by addition of the analog, whereas growth of the strain on glycerol plus cyclic AMP ceases im mediately upon addition of DG. These results suggest that the formation of PTSM is dependent on cyclic AMP. In addition, CA8306B grown on glycerol plus cyclic AMP can immediately utilize mannose when transferred to a medium containing mannose as a sole carbon source, whereas the same strain grown on glycerol without cyclic AMP cannot utilize mannose when so transferred. These results suggest that the formation of PTSM does not require an exogenous inducer.
Inhibition of in vitro peptidoglycan biosynthesis in Escherichia coli by guanosine 5′-diphosphate 3′-diphosphate
Authors: Ishiguro Edward E. , Ramey William D.
Published: May 2010

Physiological concentrations of guanosine 5′-diphosphate 3′-diphosphate (ppGpp) inhibited the synthesis of lipid intermediates and peptidoglycan catalyzed by a particulate enzyme preparation from Escherichia coli. The inhibition of these reactions was dependent on the concentrations of ppGpp and MgCl2 in the assay. The degree of inhibition of lipid intermediate synthesis decreased as the molar ratio of MgCl2 to ppGpp was increased, and no inhibition was observed above a MgCl2 to ppGpp ratio of 2.5. The synthesis of peptidoglycan was more sensitive to inhibition by ppGpp, and significant inhibition occurred under conditions where lipid inter mediate synthesis was unaffected (i.e., at MgCl2 to ppGpp ratios of 2.5 or more). A variety of other nucleotides did not inhibit the synthesis of lipid intermediates and peptidoglycan.
Bactericidal concentrations of methylglyoxal produced by heated cells of Streptococcus faecalis
Authors: Payne J. , Hilton M. G. , Gooch J. E. T.
Published: May 2010

Cells of Streptococcus faecalis that survived heating for 21 min at 60 °C were killed when resuspended at an initial cell density of about 1 × 108 viable units/mL and incubated at 33 °C for 24 h in a no-growth medium containing potassium phosphate buffer, pH 7.1, glucose, and casein hydrolysate. When such heated cells were resuspended at an initial cell density of about 1 × 107 viable units/mL or lower, subsequent cell death was reduced at least 10 000-fold. Unheated cells incubated under similar conditions at about 1 × 108 and 1 × 109 viable units/mL did not die. Cell death was due to a toxic compound synthesized by the heated cells, and supernatants from incubations showing a bactericidal effect contained a component, absent in nonlethal supernatants, that reacted with 2,4-dinitrophenylhydrazine. Thin-layer chromatography, mass spectrometer analysis, and the visible spectrum of the 2,4-dinitrophenylhydrazine derivative of the unknown and authentic methylglyoxal, and the positive response shown by the free unknown compound when used as a substrate for glyoxalase I, suggested that methylglyoxal was the bactericidal compound. Solutions of authentic methylglyoxal were bactericidal at concentrations above 0.2 mM and lethal supernatants contained about 1 mM methylglyoxal, whereas supernatants that were not lethal contained <0.02 mM methylglyoxal.
Structural polypeptides of cholera bacteriophage
Authors: Chaudhuri K. , Maiti M.
Published: May 2010

The structural polypeptides of the cholera bacteriophage [Formula: see text] have been analysed by sodium dodecyl sulphate – polyacrylamide gel electrophoresis. Eight different polypeptides were identified. The apparent molecular weights of the polypeptides were 143 000, 96 500, 68 000, 53 000, 37 500, 29 500, 21 000, and 13 500, respectively. The percentage of total protein corresponding to each polypeptide was estimated.
A putative baculovirus in the ichneumonid parasitoid, Mesoleius tenthredinis
Authors: Stoltz Donald B.
Published: May 2010

A virus was found in the ovarial calyx tissue of Mesoleius tenthredinis, an ichneumonid parasitoid; the "infection" was present in all females thus far examined. Virions were morphologically similar to typical baculoviruses. Apparent uncoating of viral nucleocapsids at nuclear pores was observed, indicating that reinfection of the calyx epithelium may occur. Electron microscopy of DNA extracted from calyx tissue suggests that the viral genome may be circular, and of high molecular weight.
Polydisperse viral DNA's in ichneumonid ovaries: a survey
Authors: Stoltz Donald B. , Krell Peter J. , Vinson S. Bradleigh
Published: May 2010

Viruses are described from several genera of ichneumonid parasitoids. New morphologic categories have been observed, one of which is similar to typical baculoviruses. Calyx particles from several species were found to contain polydisperse DNA's. An electrophoretic method for screening individual field-collected wasps for the presence of such DNA's is reported. DNA profiles obtained by this procedure were sufficiently consistent, within any particular affected species, to suggest that they could provide useful taxonomic information.
The Anderson–Baird-Parker direct plating method versus the most probable number procedure for enumerating Escherichia coli in meats
Authors: Rayman M. K. , Aris B.
Published: May 2010

Comparison of the Anderson–Baird-Parker direct plating method (DP) and the North American most probable number procedure (MPN) for enumerating Escherichia coli in frozen meats revealed that the DP method is more precise and yields higher counts of E. coli than the MPN procedure. Any of three brands of membrane filters tested was suitable for use in the DP method.
Physiological and ultrastructural characterization of a new acidophilic Thiobacillus species (T. kabobis)
Authors: Reynolds D. M. , Laishley E. J. , Costerton J. W.
Published: May 2010

A new autotrophic acidophilic Thiobacillus sp. was isolated from acidic soil adjacent to a natural gas processing plant's sulfur stockpile. This isolate metabolized S2O32− to S4O62− during growth and could not reoxidize this product; instead, the remaining S2O32− substrate was oxidized to SO42− in the stationary phase which represented a significant metabolic change as compared with other acidophilic thiobacilli. In contrast the isolate oxidized S0 to H2SO4 during log-phase growth with no S4O62− being formed. Ultrastructural studies revealed that the isolate's cytoplasm contained unidentified membrane-bound granules, volutin type bodies, and carboxysomes. Cleavage planes within the cell wall revealed a pattern of highly ordered subunits in the outer leaflet of the outer membrane and these ordered subunits were also discerned through the eutectic at the cell surface. This regular structure was not observed at the surface of cells of other acidophilic thiobacilli. The isolate bears a single pilus and one unusually long polar flagellum. The physiological and ultrastructural data are discussed in relation to other known thiobacilli and show this isolate to be a new Thiobacillus sp. named T. kabobis.
Determination of the total rates of synthesis and degradation of RNA in a bacterial culture
Authors: Yamazaki Hiroshi , Leung Kwok-Luen
Published: May 2010

A radioactive method for determining the total rates of synthesis and degradation of RNA in a bacterial culture has been developed. The rates (which are expressed as moles of AMP residue transferred per unit DNA per unit time) are calculated from the amount of radioactivity accumulated in the RNA pool by taking into account (i) the increasing specific activities of a precursor triphosphate and RNA, (ii) the withdrawal of radioactivity from the RNA pool by degradation, and (iii) the increasing DNA content of the culture. The method is applicable not only to "balanced" accumulation where DNA and RNA accumulate in a constant proportion, but also to "unbalanced" accumulation. Examples illustrating the application of this method are described.
Hybridization studies within the genus Schizosaccharomyces Lindner
Authors: Johannsen Elżbieta
Published: May 2010

Africa Hybridization studies based on the prototrophic selection technique, involving the use of auxotrophic mutants of strains of five accepted species of the genus Schizosaccharomyces, are reported.Intrastrain recombinants were recovered in five out of six tested parental pairs. Interstrain recombinants were recovered from crosses involving strains of S. japonicus and strains of S. pombe. No recombinants were recovered in 62 interspecific crosses involving all possible combinations of the six representatives of the genus.
Enzymatic reduction of mercurous and mercuric ions in Bacillus cereus
Authors: Izaki K.
Published: May 2010

A strain of Bacillus cereus, which can grow in nutrient broth containing 50 μM HgCl2, was isolated from soil. Mercurous or mercuric ion dependent oxidation of reduced NADPH was demonstrated in crude extracts of cells grown in nutrient broth containing 10 μM HgCl2. The properties of this mercuric reductase were similar to those of the enzymes from R factor bearing Escherichia coli in substrate specificity, heat stability, requirement of sulfhydryl compounds, sensitivity to some heavy metal ions, and molelcular weight.
Intrinsic limitations on the continued production of the antibiotic patulin by Penicillium urticae
Authors: Neway Justin , Gaucher G. Maurice
Published: May 2010

The initial cause of the cessation of patulin biosynthesis in submerged cultures of Penicillium urticae was sought. The extrinsic limitations to patulin biosynthesis in fermentor cultures were successfully removed and kinetic profiles of the metabolites of the pathway and of three pathway enzymes were determined over a 60-h period. These profiles indicated that the first intrinsic limitation involved a decrease in the cellular content of the first enzyme of the pathway, 6-methylsalicylic acid synthetase. Other enzyme contents also decreased but on a significantly longer time scale. Thus the in vivo half-maximal lifetimes for the synthetase and for the m-hydroxybenzyl alcohol and isoepoxydon dehydrogenases were about 7, 17, and 19 h, respectively.
Intracellular mineralization of Bacterionema matruchotii
Authors: Ooi S. W. , Smillie A. C. , Kardos T. B. , Shepherd M. G.
Published: May 2010

Intracellular calcium phosphate mineral formation in Bacterionema matruchotii has been examined relative to two established points: the product of calcium and phosphorus levels at which spontaneous precipitation occurs (Ca × P), 50 (mg %)2, and the product at which calcium hydroxyapatite itself induces crystal growth, 35 (mg %)2. The extent of intracellular mineralization in the defined calcifying medium was determined analytically after washing the cells. Electron micrographs of B. matruchotii cells revealed needlelike crystals of mineral, typical of calcium hydroxyapatite. Bacterionema matruchotii was found to be an efficient nucleator and can bring about the formation of solid phase at a Ca × P product as low as 35 (mg %)2.
Sequential cold-sensitive mutations in Aspergillus fumigatus. II. Analysis by the parasexual cycle
Authors: Levadoux Wayne L. , Gregory Kenneth F. , Taylor Ann
Published: May 2010

From Aspergillus fumigatus I-21 (ATCC 32722), which grows at temperatures from 12 to 50 °C, three multistep, independently derived, cold-sensitive mutants unable to grow at 37 °C or below (Cs-37) were obtained by sequential exposure to ethylmethane sulfonate (strain AT2) or N-methyl-N′-nitro-N-nitrosoguanidine (AT1 and AT3). These mutants and ON5, a five-step Cs-37 mutant, were marked by mutations affecting spore color and nutritional requirements and crossed in four combinations by classical parasexual means.The heterokaryons demonstrated partial complementation with respect to auxotrophic requirements (suboptimal growth on minimal medium) and cold sensitivity (growth at 37 °C but not at 25 °C). Most presumed diploids, formed by exposure of the heterokaryons to d-camphor vapors, showed complete complementation but were unstable, as demonstrated by variations in spore sizes and markedly different ratios of segregant classes derived from different clones.Analysis of the segregants of the diploids or aneuploids, induced by Benomyl, indicated that multiple genes were responsible for cold sensitivity in each Cs-37 mutant, since segregants with various levels of cold sensitivity were obtained. The higher than predicted frequency of reversion to temperatures two or more steps back in the sequence of cold sensitivity mutations suggested that these genes or their products interacted. No Cs-37 segregant yielding a consistently lower frequency of revertants than the original mutants was obtained.
Sequential cold-sensitive mutations in Aspergillus fumigatus. III. Mechanism of cold sensitivity
Authors: Arseneau Anthony J. , Gregory Kenneth F.
Published: May 2010

The mechanism of cold sensitivity of Aspergillus fumigatus ON5, a 37 °C-sensitive mutant derived from A. fumigatus I-21 (ATCC 32722) by five sequential mutations, was investigated. The rate of in vivo protein synthesis by ON5 was not affected for 2 h following a shift from 45 to 34 °C, but the rate of in vivo RNA synthesis dropped almost immediately. The RNA polymerases of ON5 possessed wild-type activity in vitro at a nonpermissive temperature (34 °C) indicating that the reduction in the rate of in vivo RNA synthesis did not result from cold sensitivity in transcription, but was possibly a result of rapid feedback inhibition of transcription. Mutant ON5 was not able to produce ribosomes at a nonpermissive temperature as evidenced by the fact that no 3H-labelled amino acids were incorporated into the monosome, large ribosomal subunit, or small ribosomal subunit at 34 °C. Ribosomal subunit assembly or ribosomal RNA processing appears, therefore, to be the cold-sensitive cellular function in ON5.
N2-fixing vibrios isolated from the gastrointestinal tract of sea urchins
Authors: Guerinot M. L. , Patriquin D. G.
Published: May 2010

Facultatively anaerobic bacteria, capable of fixing N2 anaerobically or at low O2 concentrations, were isolated from the gastrointestinal tracts of temperate (Strongylocentrotus droebachiensis) and tropical (Tripneustes ventricosus) sea urchins. Morphological and biochemical characteristics, as well as the guanine plus cytosine content of their DNA (45.9 and 48.4 mol%), place these isolates in the genus Vibrio Pacini 1865 in the family Vibrionaceae. Members of this family have not previously been shown to fix N2. These isolates are not identical to any described species in the Vibrio genus and can be distinguished by a combination of biochemical and physiological traits.
Ultrastructure of a marine Synechococcus possessing spinae
Authors: Perkins Frank O. , Haas Leonard W. , Phillips Dawn E. , Webb Kenneth L.
Published: May 2010

Two Chesapeake Bay isolates of unicellular cyanobacteria belonging to the genus Synechococcus are described. Unicellular cyanobacteria are suspected to be important primary producers in estuarine and marine waters. One isolate (P-11-16) fluoresces red and forms green colonies. The other isolate (P-11-17) fluoresces orange and forms red colonies. Their ultrastructure is very similar to other isolates of Synechococcus except that spinae are formed and are attached to an outer wall layer not found in previously described species. The spinae are straight-walled cylinders, not flared at the base, are 44.0–65.0 nm in diameter, and range up to 2.7 μm in length. Substructure of the spinae wall consists of either material organized into stacks of rings or a strand of material helically coiled at a low (1–6°) angle. Such material yielded a 6.0–9.2 nm cross-banding periodicity. Substructure of the rings or strand appeared to consist of bar-shaped, repeating units as seen in negatively stained material.Other procaryotic cell types with spinae, which were isolated from unincubated, natural seawater, are described.
Antigenic studies on coronavirus. I. Identification of the structural antigens of human coronavirus, strain 229E
Authors: Yaseen Shehab A. , Johnson-Lussenburg C. Margaret
Published: May 2010

Antigenic analysis of human coronavirus, strain 229E (HCV/229E), using a microimmunodiffusion technique, has resulted in the detection of six virion antigens. Comparison of the effect of several different virus-disrupting agents has shown that sodium deoxycholate or Triton X-100 were the best for HCV/229E disruption. Of the six coronavirion antigens, three were identified as virus specific and the remainder as host antigens, which were present as either integrated or nonspecifically adsorbed host components. One of the virus-specific antigens was identified as the internal nucleoprotein (229E/RNP). On the basis of immunodiffusion reactions with isolated 229E/RNP it was concluded that human convalescent sera reacted specifically with the 229E/RNP antigen.
Growth characteristics at low Na+ concentration and the stability of the Na+ requirement of a marine bacterium
Authors: Gow J. A. , MacLeod Robert A. , Goodbody Margaret , Frank Diane , DeVoe Lynne
Published: May 2010

Studies of the marine bacterium Alteromonas haloplanktis 214 (formerly referred to as marine pseudomonad B-16) showed that as the Na+ concentration in the growth medium decreased from 230 to 34 mM, the lowest concentration permitting growth, the length of the lag period preceding exponential growth increased. Once growth had begun, except for a slight reduction in rate of growth at 34 mM Na+, the generation time and extent of growth remained essentially constant over the range of Na+ concentrations tested. Plate counts showed that during the lag period the numbers of viable cells introduced as inoculum into a complex medium containing 33 mM Na+ decreased exponentially before increasing. Repeated subculture of the cells at 33 mM Na+ failed to eliminate the lag period or reduce the loss of viability of the cells. The viability loss and the lag period could be eliminated either by raising the NaCl concentration to 130 mM or by adding sufficient sucrose to make the osmotic pressure of the medium equal to that obtained by adding 130 mM NaCl. In a chemically defined medium, sucrose added to maintain tonicity reduced but did not eliminate the lag periods obtained at suboptimal Na+ concentrations. Increasing the number of cells plated on trypticase agar medium reduced the Na+ concentration required to permit growth. Evidence was obtained of a requirement of A. haloplanktis for Ca2+ for growth. Ca2+ spared to a small extent the requirement for Na+ for growth. Some 1010 cells of a histidine-requiring, streptomycin-resistant mutant of A. haloplanktis 214, still viable after treatment with N-methyl-N′-nitro-N-nitrosoguanidine, were screened for capacity to grow in the absence of Na+. Since no non-Na+-requiring mutants were isolated, the requirement of this organism for Na+ would appear to be extremely stable.
Effect of growth at low Na+ concentration on the capacity of a marine bacterium to establish ion gradients and transport α-aminoisobutyric acid
Authors: Gow J. A. , MacLeod Robert A.
Published: May 2010

Cells of a histidine-auxotrophic, streptomycin-resistant mutant of marine bacterium Alteromonas haloplanktis 214 were grown at or near the lowest concentration of Na+ permitting growth (30–33 mM Na+). When suspended in solutions containing 10 mM KCl and either 30, 100, or 300 mM NaCl, the intracellular to extracellular K+ ratios after equilibration were found to be 11.6, 20.8, and 43.2, respectively. The corresponding Na+ ratios were 1.0, 0.46, and 0.62. The K+ ratios were similar to those obtained with cells of the parent organism grown at more nearly optimum Na+ concentrations, whereas the Na+ ratios were somewhat larger. Cells of the parent organism grown at 32 mM Na+ transported α-aminoisobutyric acid (AIB) at only one-third the rate and to less than one-quarter of the extent of cells grown at 130 mM Na+ even when the NaCl concentration during transport was raised to optimum levels. The Km for uptake of AIB by cells grown at 32 and 130 mM Na+ was the same but the Vmax was higher for cells grown at 130 mM. The Vmax for cells grown at both concentrations of Na+ increased as the Na+ concentration in the uptake medium increased. It was concluded that none of the observations made could account for the fact that both parent and mutant of A. haloplanktis grow at 30–32 mM Na+ only after a very long lag period, and then grow at near normal rates once logarithmic growth begins despite the fact that the osmotic pressure of the medium is very low.
Increased respiratory activity in a diploid strain of Aspergillus niger (V35)
Authors: Banerjee Santu K. , De Gita , Sen Kalyani
Published: May 2010

A diploid strain (D1) of Aspergillus niger (V35) was isolated following heterokaryosis between two morphological mutants. Compared with wild type and the parent strains, the diploid strain showed increased DNA content, O2 uptake, and succinic dehydrogenase activity.