bluuebunny/crossref_metadata_2025 huggingface dataset:
Chemotaxonomic and ultrastructural studies on three species of Tilletia occurring on wheat
Authors: Laseter J. L. , Hess W. M. , Weete J. D. , Stocks D. L. , Weber D. J.
Published: February 2010

Electron microscopic investigations and chemical analyses were made on the spores of three species of Tilletia. Frozen-etched preparations examined in the electron microscope revealed that the spore walls of both T. foetida (smooth external surface) and T. caries (reticulate surface with some hair-like projections) contain two layers. The spore wall of T. controversa (complex reticulate surface with many hair-like projections) contains three layers. The outer layer in T. controversa has granular regions which form a reticulated pattern on the surface. The hydrocarbon content of the three Tilletia species was essentially the same. The compounds in benzene and the methanol (free fatty acids) fractions gave distinct gas chromatographic patterns for each of the three species. T. foetida was the highest in saturated fatty acids with T. controversa second followed by T. caries. The reverse situation existed with respect to the unsaturated fatty acids.
Preparation and properties of diphtheria toxoids in submerged culture. III. Development of a new semisynthetic medium
Authors: Stainer D. W. , Corkill J. M. C. , Scholte M. J.
Published: February 2010

A new medium has been developed which does not contain any meat digest products and is suitable for the deep-culture production of high-potency diphtheria toxins. The main ingredient is a commercially available, tryptic digest of casein known as N.Z. Amine type A. It has been found that when the iron, calcium, and phosphate levels in the medium are carefully controlled by suitable additions of ferrous sulphate, calcium chloride, and inorganic phosphate solutions, high levels of diphtheria toxin are regularly produced (200 Lf/ml in a 48-hour growth period).
The inactivation of the nuclear polyhedrosis virus of Trichoplusia ni by gamma and ultraviolet radiation
Authors: Jaques R. P.
Published: February 2010

The activity of the nuclear polyhedrosis virus of Trichoplusia ni was reduced by 90% when exposed as an aqueous suspension of polyhedra to a dose of 3 × 105 rads of gamma radiation. A dose in excess of 1 × 107 rads completely inactivated the virus in suspensions. The virus was more readily inactivated when exposed as dry deposits of polyhedra than as aqueous suspensions. Bacterial contaminants in the viral suspensions were more sensitive to gamma radiation than was the virus but the virus was the more sensitive to ultraviolet light.
Variation in susceptibility of chick embryo tissues to infection with Rous Sarcoma virus in vitro
Authors: Bather R. , Wong Anna , Sweeny P. R.
Published: February 2010

Second-generation whole chick embryo cultures were compared with second-generation limb bud, somite, and kidney cultures of various ages in their ability to support Rous Sarcoma virus infection. Limb bud cells yielded the highest proportion of infected cells and kidney cells the lowest 48 hours after infection in vitro. Cultures prepared from 9-day embryos were more susceptible to infection than those from younger or older embryos. When tissues from 9-day embryos were used for the in vitro assay of three strains of Rous Sarcoma virus, limb bud cells yielded slightly higher focus counts in each case than whole embryo, approximately 0.5 log higher than somite and approximately 2.0 logs higher than kidney cells. Limb bud cultures also showed less tendency to clump and foci were more easily counted than in cultures from the other tissues.
An evaluation of the taxonomy of Propionibacterium
Authors: Malik A. C. , Reinbold G. W. , Vedamuthu E. R.
Published: February 2010

The object of this study was to reevaluate speciation of Propionibacterium by using numerical taxonomy. Fifty-six cultures representing eight species were studied. Thirty-eight morphological and physiological features were employed in the calculation of matching coefficients which were used to sort the cultures into groups. The results suggest a need for species consolidation; for example, Propionibacterium shermanii could appropriately become P. freudenreichii var. shermanii. Close resemblances were found between P. rubrum, P. peterssonii, and P. jensenii. Propionibacterium arabinosum and P. pentosaceum formed another mutually similar group. Further studies using additional cultural, physiological, serological, genetic, and phage host-range characteristics should be instituted to establish an improved classification of propionibacteria.
Influence de la température sur le développement du virus Sindbis et la production d'interféron en cultures cellulaires
Authors: Lab Michel , Tinland Roberte , Kirn André
Published: February 2010

The development of Sindbis virus in mouse embryo fibroblasts was found to vary according to the temperature of incubation. An augmentation in these temperatures was followed by a prolongation of the lag period and a decrease in the final yield. At 38 °C, 39 °C, and 40 °C the virus titer was respectively 50%, 16%, and 1.3% of that observed at 36 °C.Interferon production at 38 °C was equal to, or greater than, at 36 °C but at 39 °C and 40 °C it was respectively 1.4 and 5 times lower than that found at 36 °C.These results permit us to presume that the inhibition of Sindbis virus development at supra-optimal temperatures cannot be attributed to an increase of interferon production.
Cell division in a species of Erwinia. XI Some aspects of the carbon and nitrogen nutrition of Erwinia species
Authors: Grula Mary M. , Smith R. W. , Parham C. F. , Grula E. A.
Published: February 2010

The species of Erwinia used in cell division studies (Grula 1960a) will grow on L- or D-aspartic acid, but no other amino acid, as a sole source of carbon, nitrogen, and energy. Ammonia is utilizable as a sole source of nitrogen; in this case the rate and extent of growth are significantly influenced by the carbon source. Of all compounds tested, malic acid supports the most rapid and abundant growth in an ammonium chloride – mineral salts medium. Added pantothenate often stimulates growth in ammonium chloride media, but not in aspartic acid media. Growth in an ammonium chloride – glucose – salts medium is rather slow and limited. Marked stimulation occurs by supplementation with intermediates of the Krebs cycle, even though the compound supports little or no growth as a sole carbon source. Neither L-glutamic acid nor α-ketoglutaric acid supports growth as a sole carbon source; this is believed to result from impermeability of the cell to these compounds.
Thermally induced leakage of cellular material and viability in Vibrio marinus, a psychrophilic marine bacterium
Authors: Kenis Paul R. , Morita Richard Y.
Published: February 2010

Vibrio marinus MP-1, an obligate psychrophilic marine bacterium, was severely damaged when heat-shocked in growth medium. Cells heat-shocked at 20, 23, and 25 C in growth medium released 260 mμ absorbing material (nucleic acids and nucleotides), orcinol-reacting material (RNA), ninhydrin-reacting material (amino acids), malic dehydrogenase, and glucose-6-phosphate dehydrogenase increasingly at higher temperatures. Older cultures were found to be more resistant to thermal death, lysis, and leakage. No significant leakage or lysis could be detected after the heat-shocking of stationary phase cells in growth medium for 120 min when more than 99.9% were killed. Cells in the log phase of growth were the most sensitive to death, leakage, and lysis. After 95% were killed at 25 C, and 94% at 20 C, cells began to release intracellular materials. Leakage and lysis occurred concomitantly after death. Loss of membrane permeability control before death would, therefore, not be indicated. It is suggested that the increased sensitivity to heat in young cultures may be attributed to thermolabile synthetic mechanisms involved in rapidly growing cultures.
Selective enhancement of glycolytic activity by incubation of yeast cells in sugars and polyols
Authors: Spoerl Edward , Doyle R. J.
Published: February 2010

Incubation of yeast cells for 21 hours in solutions of certain sugars and polyols produces cells capable of forming CO2 from glucose at a high rate and without an initial lag as compared to cells starved by incubation in water. Other sugars and other compounds, including amino acids, purines and pyrimidines, and organic and inorganic salts, were ineffective or reduced CO2 production. Readily metabolized sugars were effective at concentrations of 0.001 M, poorly metabolized sugars required higher concentration, and non-metabolized sugars were ineffective. However, mannitol and sorbitol, non-metabolized polyols structurally related to utilized sugars, were effective. Alcohols and polyols added to the cells after incubation in water overcame the lag period. Sugars produced a persistent change, acted faster than polyols, and were more effective in the presence of non-effective compounds. Readily utilized sugars at high concentrations reduced cell viability and the decarboxylase- and CO2-producing capacities of cell extracts. The nicotinamide adenine dinucleotide contents of extracts did not indicate deficiencies, and differences in adenosine triphosphate contents appeared not to be significant. The data may be interpreted as evidence for an effect by the sugars and polyols primarily upon intracellular membranes.
Effects of nitrogenous compounds on sclerotium formation in Aspergillus niger
Authors: Agnihotri V. P.
Published: February 2010

The effects of different nitrogen sources on growth and sclerotial production by Aspergillus niger were determined on a synthetic agar medium. The organism used inorganic, organic, and ammonium nitrogen for growth and sclerotial production. Among the ammonium compounds tested, the chloride, phosphate, sulfate, and carbonate were used poorly, but the nitrate was well utilized. Addition of organic acids to ammonium compounds increased sclerotial production. Raising the concentration of sodium nitrate to a certain level (0.15%) increased the number of sclerotial initials and the number and weight of those which matured. Sodium nitrite curtailed mycelial growth and prevented production of sclerotia. Utilization of nitrite was accelerated by adjusting the pH on the alkaline side from 7.5 to 9.0. Urea supported poor sclerotial production; thiourea inhibited it. Of the amino acids, histidine yielded the most and arginine the least number of sclerotia. In lysine medium, the white cottony sclerotial initials remained fluffy even after 20 days. Sclerotial production decreased significantly when proline, glutamic acid, or leucine were omitted from the basal medium containing 10 amino acids. In general, no correlation existed between the number of sclerotia formed and the dry weight they attained on different nitrogen sources. With certain nitrogen sources sclerotial initials failed to mature.
The induction of dodine tolerance in Fusarium oxysporum f. melonis: a technique applicable to the study of the bionomics of soil-borne fungal pathogens
Authors: MacNeill B. H. , Sabanayagam J. V.
Published: February 2010

An ultraviolet-induced mutant strain of Fusarium oxysporum f. melonis which can be selectively recovered from soil and positively identified without recourse to tedious pathogenicity tests is described.
Effect of atrazine on growth activity of Sclerotium rolfsii and Trichoderma viride in soil
Authors: Rodriguez-Kabana R. , Curl E. A. , Funderburk Jr. H. H.
Published: February 2010

Effect of the soil-applied herbicide atrazine (2-chloro-4-ethylamino-6-isopropylamino-s-triazine) on growth activity of Sclerotium rolfsii and Trichoderma viride was determined in soil culture. The fungi were grown axenically in flasks of sterilized soil containing 0, 8, 20, 40, 80 μg of atrazine per gram of soil, and CO2 evolution was measured at intervals over a period of 19 days for the pathogen and 14 days for T. viride. For S. rolfsii, maximum CO2-carbon was produced in soil with 8 μg of atrazine, this being significantly above the O-herbicide control. Higher concentrations greatly inhibited activity of the pathogen. Correlation coefficients revealed that total production of CO2-C was closely related to amount of NO3-nitrogen consumed and titratable acidity produced (mostly oxalic acid); soil pH decreased with increased activity of the fungus. T. viride grew very rapidly in all treatments, activity being most accelerated between 3 and 10 days after inoculation. Production of CO2-C for all treatments above 8 μg indicated a stimulatory effect upon this fungus. Economic coefficients relating total CO2-C to amount of NO3-N consumed were highest for the 80-μg atrazine treatment and declined with decreasing concentration. Soil pH increased from an initial value of 6.4 to 7.4, with no significant differences between treatment.
Ultrastructural differences in the exosporium of the Sterne and Vollum strains of Bacillus anthracis
Authors: Kramer M. J. , Roth Ivan L.
Published: February 2010

Spores from three different strains of Bacillus anthracis were examined by electron microscopy for the presence of a hair-like nap previously reported to be present on the exosporium of spores of the Sterne strain (avirulent). In addition to that strain, the Vollum strain (virulent) and a rough, avimlent variant of the Vollum were utilized in the current studies.Spores were fixed with Kellenberger's standard OsO4 fixative and embedded in Maraglas. Thin sections were poststained with various combinations of the following: potassium permanganate, uranyl acetate, lead citrate. The nap on the exosporium of spores of the Sterne strain was revealed most clearly when thin sections were poststained with all of the aforementioned stains. Post-staining by a single application of any of the three reagents resulted in a nap that was barely perceptible.The surface of the exosporium of spores from the Vollum strain and the rough, avirulent variant was found to be quite different from that of the Sterne strain. On the two former, the surface layer is approximately one-third as thick as the layer of hairs in the nap on the latter.
The clostridial flora of marine sediments from a productive and from a non-productive area
Authors: Smith Louis DS.
Published: February 2010

Samples of marine sediment from the western equatorial Atlantic and Caribbean and from the Peru Current area of the Pacific were examined for Clostridia. Samples of sediment from the Peru Current area contained more species of Clostridia, especially saccharolytic species. Six virulent strains of Clostridium novyi and 14 strains of Clostridium perfringens were isolated from the samples of sediment from the Peru Current area, although none was isolated from sediment samples from the Atlantic and Caribbean. Sediment samples from the latter area contained a higher proportion of frankly proteolytic and amino acid utilizing clostridia.
Interferon production in cell cultures derived from various chick embryo tissues
Authors: Gandhi Sunidhkumar S. , Stewart Robert B.
Published: February 2010

A study of interferon yield in cell cultures prepared from a variety of chick embryo organs exposed to three strains of influenza type A virus showed that both virus and cells differed in their capacity to induce and produce interferon. The WS strain of virus was superior to the PR8 and NWS as an interferon inducer, and cell cultures prepared from chick embryo lung produced higher titers of interferon than did cells from other organs.
Developmental studies on the true slime mold Echinostelium minutum
Authors: Haskins Edward F.
Published: February 2010

Six cultures of Echinostelium minutum were isolated from dead grass. Single spores and myxamoebae of these isolates produced protoplasmodia and sporangia; hence there was no indication of the presence of a mating-type factor. One isolate, D-3, was established in monoxenic culture with Aerobacter aerogenes and used for subsequent studies. Myxamoebae grown in a dilute glucose – peptone – yeast extract broth had a minimum generation time of 13 h. Conversion of myxamoebae into swarm cells occurred in a liquid environment at a rate independent of the concentration of myxamoebae between 1 × 105–1 × 106 cells/ml. Protoplasmodia, which multiplied by binary fission, had a minimum generation time of 12 h on Ionagar No. 2. Maximum conversion of protoplasmodia into fruiting bodies was produced by subculture to Ionagar No. 2, with approximately 100% conversion being obtained within 48 h. Nearly 100% of the spores were viable if the sporangia matured in the absence of bacterial growth.
Serological characterization of γM (19 S) and γG (7 S) rabbit antibodies in response to Entamoeba histolytica antigens
Authors: Khan Z. Ali , Meerovitch E.
Published: February 2010

Entamoeba histolytica (DKB strain) antigen mixed with an equal volume of complete Freund's adjuvant was injected at multiple sites into three rabbits. Primary response sera were drawn 1, 2, and 3 weeks after the first injection. Two injections of antigen were given in the fourth week, at 3-day intervals. The secondary response sera were drawn 5, 6, and 12 weeks after the beginning of immunization. A steady hemagglutination (HA) titer of 1:128 was obtained with all the three primary response sera, while the secondary response sera showed HA titers of 1:2000 to 1:8000. The 0.1 M 2-mercaptoethanol treatment of these sera reduced, but did not completely obliterate, their HA activity. The HA activity was detected in both the pooled γM and γG classes of immunoglobulins of the primary and secondary response sera; the immunoprecipitating activity was confined to the γG class. 2-Mercaptoethanol treatment completely destroyed the antibody activity of γM fractions without affecting that of the γG fraction. Repeated immunoelectrophoresis runs of the whole sera and pooled γM and γG fractions showed variable numbers of precipitin bands at the γG position but none at the γM and γA positions.
Studies on morphogenesis in a blue-green alga. I. Effect of inorganic nitrogen sources on developmental morphology of Anabaena doliolum
Authors: Singh H. N. , Srivastava B. S.
Published: February 2010

Spore germination, heterocyst production, hormogone formation, and sporulation are the morphogenetic stages in the developmental cycle of Anabaena doliolum Bharadwaja. In basal medium sporulation is simultaneous while heterocyst formation is sequential. Nitrate, nitrite, and ammonium nitrogen inhibit sporulation and heterocyst formation. The degree of inhibition depends on the concentration and source of inorganic nitrogen. Nitrate and nitrite induce lysis which is concentration dependent and circumscribed by time, i.e., up to a certain stage the lytic events are preventable by transfer to basal medium, but beyond this stage they become inevitable and complete lysis occurs even in the absence of nitrate or nitrite. The sequential differentiation and spatial relations of heterocysts in a growing filament are characteristic of each nitrogen source and indicative of the polarity involved in the gradient of heterocyst formation.
An immunologic comparison of five murine leukemia viruses grown in tissue culture
Authors: Brown Eric R. , Rohlfing Stephen R. , Schwartz Steven O.
Published: February 2010

Attempts were successful to develop tissue culture cell lines of murine origin capable of supporting the GC and S63 murine viruses. Viruses from this source were used as antigens to prepare antisera in rabbits. These sera cross-reacted with Moloney, Friend, and Rauscher antigens prepared similarly; however, dilution techniques disclosed that the S63 and GC viruses contain a specific antigen not related to the Rauscher, Friend, Moloney agent. Attempts to grow these two agents (S63 and GC) on J111 cells (a human leukemia) failed.
Effect of soil moisture levels on nitrification
Authors: Dubey H. D.
Published: February 2010

Nitrification of 100 p.p.m. added NH4-N was studied in two soils of Georgia. Moisture levels tried were equivalent to those equilibrated at soil tension of 15, 8, 4, 2, 0.3, 0.0 bars on the release curve and a flooded condition. Moisture was applied as crushed ice in a cold room at −5 °C. Samples were incubated at 25 °C with a constant stream of humidified air passing over them. Nitrification rate in Cecil sandy loam increased as the soil moisture content increased from 15 to 2 bars and decreased thereafter. Marked nitrification occurred even under flooded conditions. Unaccounted-for nitrogen amounted to 30% under flooded condition. Nitrification in Norfolk loamy sand was exceptionally high, nitrification being 73% complete within 2 weeks at 15 bars. There was practically no difference in nitrification at 15 to 0.3 bar. Unaccounted-for nitrogen amounted to over 60% in flooded soils.
Localisation du matériel antigénique du virus de la densonucléose au cours de l'infection chez Galleria mellonella L.
Authors: Kurstak E. , Stanislawski-Birencwajg M.
Published: February 2010

not available
The effect of superinfection by T4r+ coliphage on the deoxyribonucleases of induced Escherichia coli Y10 (λ)
Authors: French R. C. , Barrens M.
Published: February 2010

In studying the Escherichia coli Y10 (λ)-T4r+ coliphage system, it was found that T4 excluded intracellular lambda, or lambda excluded T4, depending upon the experimental conditions. Either event was correlated with a significant increase in the specific activity of free intracellular DNase (deoxyribonuclease). During the first 20 minutes after induction of lambda by ultraviolet light, there was no increase in DNase specific activity and the cells responded to T4 as if they were non-induced. Adsorption of T4, or of T4 inactivated by ultraviolet light, led to a rapid increase in free intracellular DNase, the arrest of lambda replication, and infection of the cells by T4. From 20 to 60 minutes after induction there was a progressive increase in free intracellular DNase, accompanied by an increasing ability of the cells to resist T4 infection.The RNase (ribonuclease) treatment of all cellular extracts, whether from normal cells or from cells infected with T4 or lambda, led to a considerable enhancement of DNase activity. This treatment showed that an increase in total DNase activity occurred by 40 to 60 minutes after lambda induction, but failed to reveal any such increase in total DNase activity resulting from successful T4 superinfection.
Thermally induced degradation of staphylococcal ribosomes
Authors: Haight Roger D. , Ordal Z. John
Published: February 2010

Heating of partially purified Staphylococcus aureus MF-31 ribosomes at temperatures ranging from 37 C to 55 C in buffer containing magnesium, phosphate, or ethylenediaminetetraacetic acid (EDTA) caused the degradation of the ribosomes. The degradation in phosphate was similar to that in EDTA but was greater than that in magnesium. Polynucleotide phosphorylase and ribonuclease were implicated as the enzymes involved. Degradation was stimulated by heat at temperatures comparable to those at which sublethal injury and ribosome loss occurred in the intact resting cells.
A comparative study in vivo of enzyme activities in batch, continuous, and phased cultures of a pseudomonad grown on phenylacetic acid
Authors: Kurz W. G. W. , Dawson P. S. S. , Blakley E. R.
Published: February 2010

A strain of Pseudomonas was grown with phenylacetic acid as the carbon source in batch, continuous, and phased cultures. The cellular activities of the inducible enzymes involved in the sequential degradation of phenylacetic acid [phenylacetic acid →p-hydroxyphenylacetic acid →3,4-dihydroxyphenylacetic acid →δ-carboxymethyl-α-hydroxymuconic semialdehyde] varied with the above methods of culture, and illustrate microbial reaction to environment (10). The effect of substrate concentration on the activity of the enzymes in the metabolic breakdown of phenylacetic acid is discussed.The changes observed in the cells show some of the disadvantages inherent in batch cultivation methods for the production of certain enzymes and some of the relative advantages in chemostat and continuous phased cultures for obtaining higher yields.
Notes on Pasteurella tularensis isolated from a vole, Microtus oeconomus Pallas, in Alaska
Authors: Rausch R. L. , Huntley B. E. , Bridgens J. G.
Published: February 2010

In October, 1963, during a time of abundance of microtine rodents, Pasteurella tularensis was isolated from a northern vole, Microtus oeconomus Pallas, at the Ugashik Lakes on the upper Alaska Peninsula. The morphological, cultural, and serological characteristics of this isolate are described, and comparative virulence in experimentally inoculated animals, including series of indigenous rodents, is discussed. The isolate was less virulent for rabbits and guinea pigs than was that which has been isolated previously from ticks, Haemaphysalis leporispalustris (Packard), in Alaska, and was also less virulent for these animals than was strain SCHU S4. The isolate from the vole seemed to resemble most closely the Eurasian strain of P. tularensis, as might be expected on zoogeographical grounds. A distinguishing feature of the isolate was its ability to grow readily on blood agar in the absence of cystine. The relatively high rate of subclinical tularemia in man in northern and western Alaska, as indicated by the results of serological tests, may be attributable to this organism. Water-borne bacteria may be the source of infection in man.
Carbon dioxide fixation by cell-free extracts of group D streptococci
Authors: Lachica Victor F. , Hartman Paul A.
Published: February 2010

Cell-free extracts of group D streptococci incorporated 14CO2 into aspartate. Pyruvate was the acceptor of CO2 for Streptococcus faecium; phosphoenolpyruvate was the CO2 acceptor for S. bovis; and both substrates were CO2 acceptors for S. faecalis. The enzymes, by which the CO2 fixation was effected, appear to be pyruvate carboxylase for S. faecium, phosphoenolpyruvate (PEP) carboxykinase and PEP carboxylase for S. bovis, and pyruvate carboxylase and PEP carboxykinase for S. faecalis.
Enzymatic studies of the iron-oxidizing bacterium, Ferrobacillus ferrooxidans: evidence for a glycolytic pathway and Krebs cycle
Authors: Andersen K. J. , Lundgren D. G.
Published: February 2010

Whole cells and cell-free extracts of the chemolithotroph, Ferrobacillus ferrooxidans, were used to investigate certain enzymatic reactions related to the glycolytic pathway and Krebs cycle measuring oxygen uptake manometrically; most glycolytic pathway and Krebs cycle intermediates when used as substrates were oxidized. With the use of specific enzyme assays, most of the enzymes of the glycolytic pathway and Krebs cycle were detected in crude cell-free extracts. Glucose-6-phosphate dehydrogenase and 6-phosphogluconate dehydrogenase, enzymes of the hexose monophosphate pathway, were not found.
Cyanide resistance and cyanide utilization by a strain of Bacillus pumilus
Authors: Skowronski Boleslaw , Strobel Gary A.
Published: February 2010

A strain of Bacillus pumilus was isolated from Fargo clay in a field near Fargo, North Dakota, which had been cropped in flax 73 consecutive years. This bacterium had an unusual ability to survive saturated solutions of potassium cyanide. The optimal growth conditions of this strain of Bacillus pumilus in the standard medium with 10−1 M cyanide as well as its morphological changes to a filamentous form under the influence of cyanide were established. Both 14CO2 and 15NH4+ were produced in cultures of the organism during labelling experiments in which K14C15N was fed, supporting the idea of cyanide utilization by this bacterium. Oxygen uptake studies by the filamentous form in the presence of 10−1 M KCN suggested that it has an extreme tolerance to cyanide. This is the first report of a bacterium being able to survive solutions of KCN up to 2.5 M.
Milk-clotting activity of proteinases produced by Rhizopus
Authors: Wang Hwa L. , Ruttle Doris I. , Hesseltine C. W.
Published: February 2010

Rhizopus oligosporus NRRL 3271 produces an enzyme having high milk-clotting activity. High yields of the enzyme were noted in the culture filtrates of milk, wheat flour, or wheat bran. The enzyme was stable at 40 °C, or below, but its activity was destroyed rapidly by heating at 60 °C. The enzyme was fairly stable between pH 3 and 6 and very unstable at a pH below 2 or above 7. The enzyme was recovered from the culture filtrate by ammonium sulfate fractionation (30–75% saturation). When the enzyme preparation so obtained was chromatographed on a DEAE-cellulose column and eluted by salt gradient, four active components were noted, two of which accounted for most of the activity. The NRRL 3271 enzyme and animal rennin behave similarly toward the pH of milk, added calcium chloride, and sodium chloride. Although the NRRL 3271 enzyme caused a higher degree of proteolysis than did rennin, the proteolysis apparently was not high enough to interfere with curd formation. Therefore, the NRRL 3271 enzyme merits further study as a potential replacement for rennin or as an adjunct to be incorporated into rennin for the manufacture of cheese.
Two colony types of Leptospira semaranga
Authors: Smibert Robert M.
Published: February 2010

Two different colonial types of Leptospira semaranga were found to be oxidase positive, had the same spectrum of antibiotic sensitivities, and were similar antigenically. Both colony types were stable in vitro.
Ultrastructural changes in neutrophils treated with staphylococcal alpha toxin
Authors: Maheswaran S. K. , Frommes S. P. , Lindorfer R. K.
Published: February 2010

Purified alpha toxin was cytotoxic to rabbit neutrophils as revealed by electron microscopy. Cells treated with alpha toxin showed aggregation of glycogen granules, extensive degranulation, and loss of cytoplasmic ground substance. Vesicles were present within the cytoplasm and outside the cells. The nuclear lobes were round and showed chromatin dissolution. Degranulation of the cell resulted in the formation of vesicles. These ultrastructural changes, except the nuclear changes, were similar to those of leucocytes treated with P-V leucocidin.
Lack of correlation between egg yolk reaction in staphylococcus medium 110 supplemented with egg yolk and coagulase activity of staphylococci isolated from cheddar cheese
Authors: Koskitalo Lavonne D. , Milling May E.
Published: February 2010

The egg yolk reaction fails to differentiate between coagulase-positive and coagulase-negative organisms and, therefore, cannot be solely employed for the enumeration of Staphylococcus aureus in western Canadian cheddar cheese.
Extracellular complex from the culture filtrate of Ferrobacillus ferrooxidans
Authors: Agate A. D. , Korczynski M. S. , Lundgren D. G.
Published: February 2010

An extracellular complex was isolated from the culture filtrate of Ferrobacillus ferrooxidans grown on either iron or sulfur. The complex isolated from the culture filtrate of iron-grown cells was red with an absorption maxima at 500–510 mμ. This complex consisted of approximately 60% non-phosphorus lipid. Ferrous iron was exclusively associated with a lipopolysaccharide–phospholipid fraction of the complex. The sulfur complex unlike the iron complex contained approximately 70% phospholipid and was yellowish. On the basis of hexosamine and heptose values, less lipopolysaccharide appeared to be associated with the phospholipid fraction of the complex from sulfur-grown cells than from the iron-grown cells.
The production and effect of interferon on influenza virus growth in chick embryo lung epithelial and fibroblast cell cultures
Authors: Gandhi Sunidhkumar S. , Stewart Robert B.
Published: February 2010

Cultures of fibroblastic cells prepared from chick embryo lung infected with low multiplicities of influenza type A virus strains were found to produce more interferon than did cultures of epithelial cells prepared from the same organ. Fibroblastic cell cultures were also found to be more sensitive to the action of interferon than were epithelial cells with respect to the levels of infectious virus produced and the duration of interferon action. Cultures of the two cell types treated with interferon did not differ with respect to the number of cells involved in virus synthesis.
Growth characteristics of adapted and ultraviolet-induced mutants of Streptococcus salivarius resistant to sodium fluoride
Authors: Hamilton Ian R.
Published: February 2010

Despite the initial inhibition of growth, stepwise adaptation to fluoride was observed by strains of Streptococcus salivarius incubated in glucose–tryptone broth with NaF at concentrations as high as 14.3 mM. In medium at a variety of NaF levels up to 4.8 mM, the specific growth rates, for control cells never exposed to fluoride and for stepwise adapted strains were similar, but the rates for both cell types decreased inversely with the fluoride concentration in the medium. The lag period for the fluoride-adapted strains, however, was much shorter than the control (0-F) cells. On the other hand, when compared to stepwise adapted cells, ultraviolet-induced mutants resistant to similar levels of NaF gave higher growth rates and maximum growth values, and shorter lag periods. Furthermore, the yield of cell material per gram of glucose for the ultraviolet-induced strains was always higher, even at NaF concentrations twice that used for selection. The stoichiometry of glucose degradation to lactic acid by the ultraviolet-induced strains resembled that of the wild-type parent, while the adapted cells produced less lactic acid per mole of glucose. Despite the differences in growth and metabolic characteristics of the adapted and ultraviolet-induced mutants, both types of cells retained their resistance to fluoride even after passage for 500 generations in medium free of sodium fluoride.
Use of choline or betaine for fatty acid synthesis in a marine microbe
Authors: Shieh H. S.
Published: February 2010

Vegetative cells of Achromobacter cholinophagum contained the same types of fatty acids when grown either in a choline- or betaine-containing medium. The major fatty acids of this organism were 14:0, 16:0, 16:1, and 18:1. A small amount of C14 branched-chain acid also has been detected. Incorporation of radioactivity into component fatty acids of Achromobacter cholinophagum in presence of betaine methyl-14C has been determined.
Morphological transformations and lysis of Halobacterium salinarium by 4-(2, 4-dichlorophenoxy)butyric acid and related compounds
Authors: Rodríguez-Rebollo Manuel , Vázquez Cándida González
Published: February 2010

The herbicide, 4-(2, 4-dichlorophenoxy)butyric acid (4-(2, 4-DB)), inhibited growth and lysed cells of Halohacterium salinarium at a concentration of 0.21 mM, a concentration considerably less than required for inhibition by other herbicides. The effective group is the phenol ring linked to chlorine atoms.
The preparation and visualization of cell walls of hyphal fungi
Authors: Applegarth D. A. , Bozoian G. , Zintel B.
Published: February 2010

Methods are presented for the preparation of cell walls of hyphal fungi. Details of visualization of the wall preparation by using electron, phase contrast, and conventional microscopy are presented.
The effect of some salts on Thiobacillus thioparus
Authors: Keller Paulina
Published: February 2010

The effect of NaCl on Thiobacillus thioparus ATCC 8158 and on a strain of T. thioparus isolated from salt-rich Ein Bokek spring, near the Dead Sea, was investigated. Whereas the growth of T. thioparus ATCC 8158 was completely arrested by NaCl, KCl, or NaNO3 at a concentration of 0.3 M, the Ein Bokek strain tolerated 1.4 M of NaCl in the growth medium. Other salts (KCl, KNO3, CaCl2, MgCl2, and NaNO3) were significantly more toxic than NaCl. On the other hand, their effect on oxygen uptake by both strains was similar to that of NaCl.The thiosulfate-oxidizing system in cell-free extract was less affected by NaCl than that in the intact cells. Most of the effect of NaCl on this system could be attributed to inhibition of endogenous respiration. It was concluded that sodium chloride did not inhibit growth of T. thioparus through blocking its respiratory processes.
Colonization of soybean buds by bacteria: observations with the scanning electron microscope
Authors: Leben Curt
Published: February 2010

The scanning electron microscope was used to study bacteria on the surface of stipules of buds from soybean seedlings grown in a humid atmosphere.
The use of Sephadex for the electrophoretic resolution and partial purification of β-hydroxybutyric and isocitric dehydrogenases of Azotobacter vinelandii
Authors: Jurtshuk Peter , Barrera C. R. , Manning S.
Published: February 2010

A relatively quick and convenient electrophoretic method, capable of separating and partially purifying soluble enzymes from cell-free extracts, is described. The method presented has the feature of analytical applicability and is ideally used with preparatory amounts of material. This zonal technique was developed with the Svensson-Porath preparatory electrophoresis column by using Sephadex G-25 as the anticonvectant. The D(−)β-hydroxybutyric and isocitric dehydrogenases of Azotobacter vinelandii strain O were used as the marker enzymes, and both were resolved as sharply defined peaks. The combined use of ammonium sulfate fractionation and electrophoresis yielded highly active and partially purified enzyme preparations of the β-hydroxybutyric and isocitric dehydrogenases.
DNA base composition of Neisseria, Moraxella, and Acinetobacter, as determined by measurement of buoyant density in CsCl gradients
Authors: Bøvre K. , Fiandt M. , Szybalski W.
Published: February 2010

The guanine + cytosine contents (%(G + C)) of DNAs from 75 strains of asaccharolytic Neisseria, Moraxella, and Acinetobacter have been determined by measuring their buoyant densities in the CsCl gradient. The main purpose was to provide supporting evidence for taxonomic conclusions based on assay of genetic transformation to streptomycin resistance among the same strains and species.Three groups of neisseriae can be recognized, both by determination of %(G + C) and by transformation assay: (i) Neisseria flavescens and N. cinerea (46.5–49%), (ii) N. catarrhalis (41–42.5%), and (iii) N. caviae and N. ovis (44.5–45%). There is no transformation compatibility between group (i) and the other groups, whereas groups (ii) and (iii) show mutual transformation interactions. N. catarrhalis, N. caviae, and N. ovis, therefore, can also be considered as one group of nonpigmented, asaccharolytic neisseriae.Four groups of moraxellae can be distinguished: (i) Moraxella nonliquefaciens, M. lacunata, M. liquefaciens, and M. bovis (40–43%), (ii) M. osloensis (43–43.5%), (iii) M. phenylpyrouvica (43–43.5%), and (iv) M. kingii (44.5%). Although groups (ii) and (iii) are identical in terms of %(G + C), they exhibit low transformation compatibility, of the same order as between groups (i) and (ii). The distinctly higher G + C content of M. kingii DNA is consistent with its lack of transformation compatibility with other moraxellae.The similar %(G + C) range for the moraxellae and the nonpigmented, asaccharolytic neisseriae is consistent with the finding of some transformation compatibility between most of these organisms (except M. kingii) and provides additional support for the assumption that they are closely related.The Acinetobacter strains studied exhibit a wide range of G + C contents (38–45%) and hardly any transformation compatibility with neisseriae and moraxellae, even if some of them have matching %(G + C).It can be concluded that determination of the G + C contents of bacterial DNAs provides useful supplementary taxonomic data, but has only limited value as a sole taxonomic criterion.
Thermolability of protein synthesis in a cell-free system from the obligately psychrophilic yeast Candida gelida
Authors: Nash C. H. , Grant D. W. , Sinclair N. A.
Published: February 2010

A subcellular amino-acid-incorporating system from the obligately psychrophilic yeast, Candida gelida, was completely inhibited after incubation at 35 C for 30 minutes. The thermal inactivation of protein synthesis was due, in part, to the presence of unusually temperature-sensitive aminoacyl-sRNA synthetases in C. gelida extracts. Of the 13 specific synthetases examined, 7 retained less than 50% of their activity after being held at 35 C for 30 minutes. Kinetic studies of thermal inactivation of leucyl-sRNA synthetase demonstrated that this enzyme is 50% inactivated after only 7 minutes at 35 C. None of the 10 sRNA species tested was temperature sensitive. In addition to temperature-sensitive synthetases, C. gelida possesses thermolabile soluble enzymes involved in the formation of ribosomal-bound polypeptide chains.
Cell wall lipopolysaccharides from Neisseria catarrhalis
Authors: Adams G. A. , Tornabene T. G. , Yaguchi M.
Published: February 2010

Lipopolysaccharides (LPS) prepared from N. catarrhalis cells were separated into a chloroform-soluble fraction (26%) and a chloroform-insoluble fraction (74%). Both LPS fractions contained D-glucose, D-galactose, D-glucosamine, galactosamine, lipid A, ethanolamine, fatty acids, acetyl, phosphate, and protein in approximately equal proportions. The lipid A moieties prepared from the two LPS fractions were also similar in composition to each other. The fatty acids and galactosamine of the LPS fractions were recovered quantitatively in their lipid A fractions. The major fatty acid component was β-hydroxylauric acid in contrast with β-hydroxymyristic acid, which is the major fatty acid component of the lipid A of N. perflava and other Gram-negative bacteria. The lipid A of N. catarrhalis also contained a considerable amount of D-glucose and D-galactose, which are not normal constituents of lipid A fractions. The presence of amino acids (ca. 2%) in all fractions suggested that proteins were an integral part of the LPS molecules. The absence of heptose and 3-deoxyoctulosonic acid (KDO) from the N. catarrhalis LPS shows that it lacks a lipopolysaccharide "core" structure similar to that present in the LPS of N. perflava; the polysaccharide part of the LPS molecule is also compositionally different from that of N. perflava. These differences may provide additional evidence to that already accumulated from other sources that N. catarrhalis is taxonomically a "false neisseria".
A simple method for the detection of low concentration of viruses in large volumes of water by the membrane filter technique
Authors: Rao N. U. , Labzoffsky N. A.
Published: February 2010

A simple prefilter pad – membrane filter combination method is described for the detection and quantitation of low concentrations of virus in natural waters. The data obtained indicate that in surface water experimentally contaminated with poliovirus type 1 (Mahoney strain), more than 50% of the initial virus dose is recovered. The method is practical, efficient, and can be used in field studies. It was clearly demonstrated that the prefilter pad (AP25), when used by itself will adsorb viruses. A certain concentration of electrolytes (200 p.p.m. Ca2+) is necessary in water to prevent the loss of virus in filtrate when filtering is done through the membrane filter.
Distribution, characterization, and nutrition of marine microorganisms from the algae Polysiphonia lanosa and Ascophyllum nodosum
Authors: Chan E. C. S. , McManus Elizabeth A.
Published: February 2010

Quantitative studies were carried out on the bacterial populations of two associated littoral marine algae, Polysiphonia lanosa and Ascophyllum nodosum, and of the environmental seawater. Samplings conducted twice monthly from May to September, 1964, showed that numbers of bacteria on P. lanosa and in the seawater remained relatively constant while those on A. nodosum decreased in mid-summer, after an apparent spring maximum, and then gradually increased.Pure cultures of 25 isolates of frequent occurrence were studied and identified to the genus level. There was a preponderance of members of the genera Vibrio and Flavobacter (eight of each genus). Three members of the Escherichia group, two of Pseudomonas, and one belonging to each of the genera Sarcina, Staphylococcus, and Achromobacter (or Alkaligenes), as well as a pink yeast (Rhodotorula), made up the rest of the isolates.The optimum temperature for growth of most of the isolates was around 21 °C. Five of the isolates failed to grow at 30 °C. Twenty did not grow at 37 °C; of the five organisms which grew at 37 °C, growth was feeble in every case but one.Studies on the gross nutritional requirements of the marine organisms showed that 22 of the 25 isolates required a supplement of amino acids in the growth medium. Two were able to grow on basal medium; one isolate grew only in a medium supplemented with growth factors in addition to amino acids.The above findings are briefly discussed with special reference to the association between the two algae.
Simultaneous production of three phenazine pigments by Pseudomonas aeruginosa Mac 436
Authors: Chang P. C. , Blackwood A. C.
Published: February 2010

Pseudomonas aeruginosa Mac 436 was found to produce simultaneously three phenazine pigments identified as pyocyanine, phenazine-1-carboxylic acid, and oxychlororaphine. Production of these pigments on various media indicated a wide variation in yields depending on the composition of the media, but satisfactory yields of all three pigments were obtained. A scheme was developed for separation and assay of the pigments from the culture liquor. Details of production, isolation, assay, and identification are given.
Inhibition by ethionine of the growth of Neurospora crassa
Authors: Beeman Elisabeth A. , Smith Robert C.
Published: February 2010

A wild-type strain of Neurospora crassa was inhibited 30% by 0.1 μg/ml of L-ethionine. With 1 μg/ml the cultures failed to grow for the first 5 days of incubation and then they grew at a rate comparable to that of a control culture. However, the final weight of the inhibited cultures was less than that of the untreated cultures. L-Ethionine at 2.5 μg/ml completely inhibited growth of the cultures. The growth of a methionine-requiring strain of N. crassa was inhibited about 90% when the ratio of ethionine to methionine was at least 10:1. Ethionine at 0.6 μg/ml inhibited the growth of a choline-requiring mutant. α-Methylmethionine and norleucine at 1 mg/ml did not inhibit growth of the wild-type N. crassa in liquid medium. S-Ethyl-cysteine inhibited growth much less than ethionine. p-Fluorophenylalanine was as effective an inhibitor as ethionine.
Characteristics of a Mycoplasma hyorhinis strain contaminating a human fetal diploid cell line
Authors: Joncas J. , Chagnon A. , Lussier G. , Pavilanis V.
Published: February 2010

A human fetal lung cell culture contaminant possessing most of the characteristics of that described by Girardi et al. (5) was shown to belong to the M. hyorhinis-GDL group of cytopathic mycoplasma by accessory factor neutralization test. The homotypic antiserum in this test neutralized the contaminant as well as three closely related strains while it could inhibit the growth of the contaminant only on agar. The mycoplasma could be detected in tissue cultures by the acridine orange staining technique and by direct immunofluorescence. These appeared as minute coccobacillary bodies either isolated or in clumps, predominantly extracellular in the original tissue culture but apparently intracellular in monkey kidney cell culture. A titer of 106 TCID50 per 0.1 ml was obtained in monkey kidney cell culture and the cytopathic effect induced in this culture was inhibited by pretreatment of the agent with 20% ether for 18 hours at 4 C, with tris buffer at pH 3 for 3 hours, or by heating at 56 C for 3 minutes. The cytopathic effect was suppressed by chlortetracycline (50 μg/ml) and neutralized with accessory factor by specific antiserum produced in rabbit up to a titer of 8192, whereas a variety of normal human and animal sera failed to do so. The source of the contaminant could not be determined.