bluuebunny/crossref_metadata_2025 huggingface dataset:
COMPARISON OF RHIZOSPHERE MICROORGANISMS OF GENETICALLY RELATED NODULATING AND NON-NODULATING SOYBEAN LINES
Authors: Elkan Gerald H.
Published: February 2010

The microorganisms in the rhizosphere of a non-nodulating (nn) soybean strain, which has been shown to exude a nodulation-inhibitory factor(s), were compared with the rhizosphere population of a near-isogenic, normally nodulating (NN) sister soybean strain. Field and greenhouse plots were established and differential microbial counts in the rhizospheres of both strains were obtained at approximately weekly intervals during the growing season. Results of three such experiments show greatly increased numbers of actinomycetes, rhizobia, and total microorganisms in the rhizospheres of the nn plants during approximately the first 40 days after emergence. These differences gradually lessened until, as the plants reached maturity, the nn rhizospheres contained considerably lower total microbial and actinomycete populations. At intervals, microorganisms which grew on Bhat's agar were classified according to Lochhead's nutritional grouping. The nn rhizosphere contained fewer microbes able to grow on basal medium and more microbes which required the various enriched media for growth. This indicates that in addition to having numerical differences, nutritionally different groups of microbes are found in the two rhizospheres. Rhizobia were found in the roots of both soybeans but were present in higher numbers in the roots of the nodulating strain.
THE PATHOGENESIS OF COXSACKIE GROUP B VIRUSES IN EXPERIMENTAL INFECTION
Authors: Grodums E. Irene , Dempster George
Published: February 2010

The experimental findings show that in mouse-adapted strains of different Coxsackie group B types of virus, distinctly varied patterns of pathogenesis exist. In the particular host population under study, both of the B-3 strains examined are peculiarly cardiotropic for 17-day-old mice and adult mice. In contrast, the B-1 strain, while mildly cardiotropic for sucklings, neither propagates nor produces lesions in the 17-day weanlings. The age factor does not seem to have any effect upon two strains of B-5 viruses which show the same degree of moderate cardiotropism in sucklings and weanlings.It can be seen from observations made upon the brown fat that lesions are produced in adult mice with all but B-2 virus. Interpretation of the heart lesion, however, is complicated by the appearance of heart lesions in control animals of this age. These heart lesions were not observed in the control sucklings or weanlings. In spite of this, there is evidence that the B-3 virus induces specific heart lesions in adult mice.It would appear that the B-2, B-4, and the Kita strain of B-5 provoke a marked inflammatory cell response in the brain which distinguishes them from the other strains.
THE PRODUCTION OF IMMUNO-CONGLUTININ: I. FACTORS AFFECTING THE RESPONSE OF MICE TO HETEROSTIMULATION
Authors: Ingram D. G.
Published: February 2010

Mice are capable of producing immuno-conglutinin in response to hetero-stimulation. This species was used to test a number of preparations of bacteria and kaolin for their ability to stimulate immuno-conglutinin production. It was found that complement activity must be present in the serum used to alexinate the bacteria or active particles in order to produce a significant immuno-conglutinin response. The available evidence indicates that adsorbed complement is the specific stimulus for the production of immuno-conglutinin.
AN ELECTRON MICROSCOPIC COMPARISON OF BOVINE INFECTIOUS PUSTULAR VULVOVAGINITIS VIRUS AND INFECTIOUS BOVINE RHINOTRACHEITIS VIRUS IN TISSUE CULTURE
Authors: Grinyer I. , Savan M. , Studdert M. J.
Published: February 2010

An electron microscopic study of IPV and IBR viruses isolated from cattle in Canada is presented. A technique is described with which it is possible to observe the cytopathic changes occurring in the same area of a monolayer, of bovine foetal kidney cells, infected with IPV or IBR virus, with both the phase contrast and electron microscopes. The morphology of these viruses was found to be identical and no difference was observed in their intracellular development.
STUDIES ON THE RHIZOSPHERE MICROFLORA OF CITRUS TREES: II. QUALITATIVE DISTRIBUTION OF THE BACTERIAL FLORA
Authors: Rangaswami G. , Vasantharajan V. N.
Published: February 2010

Studies were made on the relative incidence of various morphological, physiological, and nutritional groups of bacteria in the rhizosphere regions of growing and non-growing roots of three species of Citrus as compared to those in the soil. Gram-negative non-sporing rods were more abundant in the rhizospheres of both growing and non-growing roots than in the soil, whereas Gram-positive rods, cocci, and sporeformers were more numerous in the soil than in the rhizospheres. Nitrate reducers, gelatin liquefiers, starch hydrolyzers, and methylene blue reducers occurred in greater numbers in the rhizospheres than in soil. Growing roots seemed to stimulate preferentially nitrate reducers and gelatin liquefiers, whereas cellulose decomposers and pectin reducers were in higher proportions in non-growing roots than in the growing roots as well as in soil. There was no significant difference between populations of azotobacter occurring in the rhizospheres and soil, but sulphur-oxidizing bacteria were absent in the rhizospheres of both growing and non-growing roots. Bacteria that require amino acids for growth were more abundant in the rhizosphere of growing than non-growing roots, whereas those requiring growth factors in yeast extract and soil extract were less abundant in the growing roots than in soil. The numbers associated with non-growing roots appeared to be intermediate between the growing roots and soil.
THE EFFECT OF DECOMPOSITION OF VARIOUS CROP PLANTS ON THE METABOLIC ACTIVITY OF THE SOIL MICROFLORA
Authors: Stevenson I. L.
Published: February 2010

Studies were undertaken to determine the changes in the soil microflora during the decomposition of plant residues. The methods used include the determination of bacterial numbers, dehydrogenase activity, and oxygen uptake with selected substrates (ethanol, amino acids, organic acids). Tests were conducted at varying intervals during a 66-day experimental period. Maximum activity was observed in all supplemented soils during the early stages of decomposition (5–10 days) followed by a rapid decline. During the first 10 days a correlation was found between numbers of microorganisms and the respiratory activity (oxygen uptake) of the soils. Analysis of the data from this period indicated that the increased metabolic activity of the soil was due partially to a preferential stimulation of the organisms and not to the effects of increased numbers alone. Nutritional grouping of bacteria isolated from the flax supplemented soil at 0 and after 6 days of decomposition indicated a shift in the microbial equilibrium, towards a higher proportion of bacteria with relatively simple nutritional requirements.
SOME FACTORS AFFECTING THE YIELD OF THE MONOCYTOSIS-PRODUCING AGENT
Authors: Beaulieu Maurice
Published: February 2010

From Listeria monocytogenes cultured at 4 °C and at 37 °C, a lipid fraction called monocytosis-producing-agent (M.P.A.) was extracted. From the cells cultured at 4 °C, twice as much M.P.A. was obtained per unit of dry weight cells. M.P.A. obtained from cells cultured at 4 °C was as effective as the one isolated from cells grown at 37 °C in stimulating monocytes production in rabbits. The time of incubation at 4 °C was varied from 5 to 10 days without significant difference in cell yield. Extraction of M.P.A. was neither quantitatively nor qualitatively enhanced by sonic oscillations at 8000 cycles. Such treatment of dead cells for as long as 105 minutes failed completely to disintegrate the organisms. Further destruction of the cell walls by sonic oscillation or shaking with glass beads contributed little to the overall yield of M.P.A.
A SHELF-TYPE GRADIENT INCUBATOR
Authors: Fluegel Walter
Published: February 2010

An inexpensive shelf incubator has been designed to hold a number of petri dishes, each at a different temperature. The design diminishes a gradient across the dish, avoiding undesirable circulation of liquid media. The heat gradient between shelves is nearly linear except at the extreme "hot" end. Long-term experiments show very little fluctuation at each measured position.
THE INFLUENCE OF PLANT ROOTS ON AUTOTROPHIC NITRIFYING BACTERIA
Authors: Molina J. A. E. , Rovira A. D.
Published: February 2010

An investigation of the effects of corn and alfalfa roots on Nitrosomonas and Nitrobacter showed a stimulation of these organisms in the rhizosphere at 15 days but not at 46 days. A rapid method of estimating Nitrosomonas populations in soils was developed which depends on the color change in brom-thymol blue with the fall in pH associated with nitrite production.In liquid media alfalfa root exudate inhibited Nitrosomonas at high concentrations but had no effect on the growth of Nitrobacter. Corn root exudate also inhibited Nitrosomonas but its effect on Nitrobacter was to reduce the duration of the lag phase without changing the generation time.
THE EFFECTS OF SELECTED STRAINS OF PIGMENTED MICROORGANISMS ON SMALL FREE-LIVING AMOEBAE
Authors: Groscop Julia A. , Brent Morgan M.
Published: February 2010

Twenty-four strains of chromogenic microorganisms were tested for their effects on five strains of small amoebae. Of the 24 strains only Serratia marcescens, Pseudomonas aeruginosa, and Chromobacterium violaceum and their pigments, prodigiosin, pyocyanine, and violacein, respectively, were found to be toxic to the amoebae.
LONG-TERM INFLUENCE OF SOIL AMENDMENTS ON GERMINATION OF CONIDIA
Authors: Griffin G. J.
Published: February 2010

Washed conidia of Gliocladium fimbriatum and Fusarium solani f. phaseoli required a carbon and nitrogen source for complete germination. Filtered aqueous extracts and membrane-expressed soil solution supported germination of washed conidia of both fungi, but germination of G. fimbriatum was completely inhibited in non-filtered aqueous soil extracts and on soil–cellophane–agar plates, whereas conidia of F. solani f. phaseoli germinated readily in both instances.The long-term influence of certain soil amendments on the capacity of the soil solution to support germination of conidia was investigated. Inhibition of germination of conidia of F. solani f. phaseoli and G. fimbriatum in filtered aqueous extracts of cellulose-amended soil with a C/N ratio higher than 25/1 and barley-amended (C/N ratio, 55/1) soil was overcome by the addition of 5 p.p.m. nitrate nitrogen to the soil during extraction. Chemical analysis of cellulose-amended (C/N ratio, ∞) soil indicated that most of the inorganic nitrogen had been immobilized. Germination in aqueous extracts of soybean- (C/N ratio, 7/1) and alfalfa-amended (C/N ratio, 18/1) soil or non-amended soil was not inhibited. Germination of F. solani f. phaseoli conidia added directly to cellulose-amended (C/N ratio, ∞) soil in 2% sucrose solution was also inhibited, whereas conidia added in 2% sucrose to non-amended soil germinated readily. Cellulose-amended (C/N/P ratio, 25/1/0.1) soil was the only soil that consistently demonstrated fungistatic activity to germination of conidia of F. solani f. phaseoli on soil–cellophane–agar plates. Membrane expressed soil solutions of the cellulose-amended soil, however, did not demonstrate fungistatic activity to germination of conidia.
CORRELATION BETWEEN HEMAGGLUTINATING ANTIBODY AND MOUSE PROTECTION IN ANTIPASTEURELLA (PASTEURELLA MULTOCIDA) SERA
Authors: Carter G. R.
Published: February 2010

Rabbits were immunized against types B and E Pasteurella multocida. The protective capacities of the sera were determined by mouse protection tests. The HA titers of these sera were determined by a standardized indirect hemagglutination test. A linear relation was observed when the protective values of the immune sera (log of the number of LD50's against which the mean of the ED50's (4.25 × 10−2 ml) protects 50% of mice) were plotted against the logs of the HA titers of the same sera.
A SYNTHETIC MEDIUM FOR EXTREMELY HALOPHILIC BACTERIA
Authors: Onishi H. , McCance Margaret E. , Gibbons N. E.
Published: February 2010

A synthetic medium, made up of 15 amino acids, adenylic and uridylic acid, glycerol, asparagine or ammonium chloride, and various salts, has been developed for halophilic bacteria. Halobacterium cutirubrum and Sarcina litoralis grew as well in this medium as in a complex medium containing casein hydrolysate and yeast extract. Growth of Halobacterium halobium, Halobacterium salinarium, and Sarcina morrhuae was slower in the synthetic medium and the final cell densities were not as great as in the complex medium.
THE EFFECT OF METAMORPHOSIS ON NUCLEAR-POLYHEDROSIS VIRUS INFECTION IN CERTAIN LEPIDOPTERA
Authors: Stairs Gordon R.
Published: February 2010

In Lepidoptera, the course of nuclear-polyhedrosis virus infection is interrupted at periods of rapid cell proliferation such as those that occur during the formation of the pupa and adult. Embryonic regenerative cells appear to be resistant to virus attack but they become susceptible after they have begun to differentiate. Thus, the new structures they form must be infected and killed before the insect will die. In this way, the incubation period of the disease is increased. When larvae were fed polyhedra 3 to 5 days before pupation, significant mortality occurred during the pupal stage.
WATER RELATIONS OF ASEXUAL SPORES OF SPHAEROTHECA MACULARIS (WALLR. EX. FR.) COOKE AND ERYSIPHE POLYGONI DC.
Authors: Jhooty J. S. , McKeen W. E.
Published: February 2010

The conidia of Sphaerotheca macularis germinate best at a relative humidity (R.H.) of 99 and 100% on glass surfaces, and germination does not occur if the R.H. is below 93%. Conidia of Erysiphe polygoni DC. germinate at 3% R.H. The water content of conidia of S. macularis and E. polygoni is 53 and 69% respectively. The osmotic pressure of S. macularis conidia is about 18 atm and their density varies from 1.10 to 1.11 g/ml. There is no significant change in the diameter and length of the conidia during germination.
EFFECT OF HIGH CO2 AND LOW O2 TENSIONS ON THE SOIL MICROBIOTA
Authors: Stotzky G. , Goos R. D.
Published: February 2010

The influence of high pCO2 and low pO2 on the microbiota derived from four tropical soils and on microorganisms in pure culture was investigated. Incubation under atmospheres containing more than 90% CO2 reduced the number of organisms developing on soil dilution plates, but most organisms recovered when the plates were subsequently incubated in air. Inhibition by high CO2 tensions was the result primarily of CO2 concentration and not absence of O2; many organisms developed under 100% N2, and presence of O2 mitigated the inhibitory effects, especially when CO2 concentration was 95% or less. The actinomycete population was most sensitive to high pCO2 and low pO2 and the fungal population least sensitive. Some fungi were capable of developing under 100% N2 and under atmospheres containing as much as 98% CO2; most identified species developed in air after exposure to the various gases. Fusarium oxysporum f. cubense was more tolerant to low O2 and high CO2 tensions than most of the soil mycobiota.
ÉTUDE D"UNE LIGNÉE DE CELLULES KB INFECTÉES CHRONIQUEMENT PAR LE VIRUS PARA-INFLUENZAE TYPE 3 : II. NOUVELLES PROPRIÉTÉS ACQUISES PAR LES CELLULES KB.EA
Authors: Daniel Philippe , Bouillant Alain
Published: February 2010

The KB.EA I strain, originated S years ago from KB cells chronically infected with myxovirus para-influenzae type 3 virus has undergone some modifications over the last 3 years. The growth rate has slowed, and is now about half that of KB cells. But the main point is that the virus produced has changed in quality. Most of the virus particles found in the supernatant liquid of infected cells no longer induce syncytial formation and they have such a weak cytopathogenic effect that the virus must be detected by hemadsorption or hemagglutination. Transfer of the KB.EA strain from Europe to Canada was followed by a partial necrosis of the growing cultures that persisted for about 2 months, whereupon normal growth reoccurred.To reproduce the transformation, two new cell systems called KB.EA II and KB.EA III respectively, were induced by infection of KB cells at two different multiplicities. KB.EA II cells, obtained with high multiplicity (1.3), produced a weak cytopathogenic variant similar to the one found with KB.EA I system; inversely the KB.EA III cells primarily infected with low multiplicity (0.013) contained cytopathic syncytial virus. With the help of these two new cell systems the attempts to reproduce the necrotic phenomenon were unsuccessful. Because it has previously been shown that the caryotypes of KB and KB.EA I cells differ, it is thought that a dual selection affecting the virus and the cells occurs during the transformation of KB.EA I cells.
DEGRADATION OF PENICILLIN G AND THREE SEMISYNTHETIC PENICILLINS BY BACILLUS CEREUS AND STAPHYLOCOCCUS AUREUS PENICILLINASE
Authors: Yurchenco J. A. , Hopper M. W. , Warren G. H.
Published: February 2010

An in vivo procedure is described for determining the relative sensitivities of potassium penicillin G and three semisynthetic penicillins to degradation by Bacillus cereus and Staphylococcus aureus penicillinases. The inactivating concentrations (IC50) of the penicillinases necessary to reduce the protective activity of each of the penicillins against an S. aureus infection in mice from PD95 to a PD50 level was determined. Conventional in vitro studies were carried out for purposes of comparison. After interaction with B. cereus penicillinase, Wy-3206 [6-(2-methoxy-1-naphthamido) penicillanic acid] had the greatest residual therapeutic activity, followed in order by nafcillin [6-(2-ethoxy-1-naphthamido)penicillanic acid], methicillin [sodium 6-(2, 6-dimethoxybenzamido)penicillinate monohydrate], and potassium penicillin G. Penicillin G proved to be the most sensitive to enzymatic degradation by S. aureus penicillinase, whereas nafcillin and methicillin were resistant to the highest concentration employed. These findings were, in general, supported by the in vitro results.
SEPARATION OF DIPHTHERIA TOXIN PROTEINS BY SEPHADEX GEL
Authors: Robb Leslie A.
Published: February 2010

Diphtheria toxin was separated on Sephadex G-100 into a slowly flocculating fraction of high molecular weight and a rapidly flocculating fraction of low molecular weight associated with the actual toxin. When detoxified, the fraction of low molecular weight forms the protective antigen, but part of this fraction polymerizes to a larger highly protective antigen molecule which can be separated from the slowly flocculating fraction on Sephadex G-200. The rapidly and slowly flocculating fractions were shown to contain distinctly different antigens with separate antibodies. A purification step based on these observations is proposed.
A CHEMICALLY DEFINED MEDIUM FOR GROWTH OF PASTEURELLA MULTOCIDA
Authors: Watko Laurence P.
Published: February 2010

The chemically defined medium of McKenzie et al. was modified by increasing dextrose and buffer and adding metallic salts. This modified medium supported growth of nine different isolates of P. multocida through 10 serial transfers. One isolate (strain X-73) was successfully subcultured through more than 100 transfers in the modified medium without change of its biochemical characteristics. Viable organisms were recovered from static cultures after 45 days" incubation at 37 C. A 1/10-ml inoculum containing approximately two or three organisms was sufficient to produce good growth within 24–48 h.
THE INDUCTION OF LAMBDA PROPHAGES BY CONTROLLED DESICCATION
Authors: Webb S. J. , Dumasia M. D.
Published: February 2010

Cells of Escherichia coli K12 (λ +) and Escherichia coli M3 (λ59) were desiccated at various levels of relative humidity (R.H.). When the cells were cultured in an enriched medium and held at 55% R.H., induction of the prophage in 36% of E. coli K12 cells and 75% of E. coli M3 cells occurred. At 30% R.H. or 70% R.H., fewer inductions took place. The maximum number of cells in which prophage induction occurred was found 15 minutes after desiccation began with E. coli K12 and immediately after the cells were dried with E. coli M3. After the attainment of maximum levels of induction, plaque-forming ability was gradually destroyed, but the rate of destruction was dependent on the R.H. at which the cells were held. The plaque-forming ability of the free viruses and of cells in which prophage induction had occurred were destroyed by prolonged desiccation at different rates. Also, the loss of colony-forming ability of the cells was more rapid than the inactivation of plaque-forming ability of either induced prophages or the free viruses. The compound, i-inositol, prevented prophage induction by desiccation and also stopped the destruction of induced prophages within the cell.It is concluded that water molecules bound to the DNA hold the prophage to the host DNA and their removal results in induction.
COMPARAISON DE TOXICITÉ DE QUELQUES ÉLÉMENTS POUR BACILLUS THURINGIENSIS VAR. THURINGIENSIS BERL.
Authors: Perron J. M. , Smirnoff W. A. , Huot L.
Published: February 2010

This study is concerned with the effects of aluminium, arsenic, boron, cobalt, copper, fluorine, iron, iodine, lithium, magnesium, molybdenum, and zinc on Bacillus thuringiensis var. thuringiensis Berliner. Addition of small quantities of the elements to the culture medium stimulated growth of the Bacillus. The effect was particularly marked during cell division, as revealed by an increase in area of the clones. The toxic effects of certain concentrations of the elements was also revealed during cell division, which, as indicated by the clonal area, was adversely affected by B, Cu, I, Mg, and Zn. F, Fe, Li, and Mo effected retardation of the cell division by as much as 12 to 48 hours. Al, As, Cu, and Mg both retarded and reduced cell division. By determining the relation between the effective limiting doses established, we were able to divide the elements into four groups. The toxicity of the elements was also revealed by its effects on the germination of the spores, clonal structure, form of the cells, time of sporulation, synthesis of the toxin-crystal, and cellular lysis.
POLYSACCHARIDES EXTRACELLULAIRES DE RHIZOBIUM MELILOTI
Authors: Amarger Noëlle , Obaton M. , Blachère H.
Published: February 2010

The composition of the extracellular polysaccharides of 10 strains of Rhizobium meliloti was investigated. Glucose, galactose, and glucuronic acid were found as components; their amounts, determined after hydrolysis as a percentage of the total sugars, varied from 82 to 86 for glucose, 13 to 16 for galactose, and 0.4 to 1.2 for glucuronic acid. No significant difference between the strains was found, which suggests a homogeneity of the extracellular polysaccharides of Rhizobium meliloti.
METABOLISM OF HISTIDINE BY PEPTOCOCCUS AEROGENES
Authors: McConnell W. B. , Horler D. F. , Westlake D. W. S.
Published: February 2010

Peptococcus aerogenes ferments histidine-α-14C to acetic, butyric, and formic acids. The distribution of carbon-14 in acetic and butyric acids was consistent with that expected if the urocanic acid pathway was used for the metabolism of histidine. Radioactive glutaconic acid also was isolated from such reaction mixtures. Glutamic acid accumulated when histidine was fermented under sodium-deficient conditions.
STUDIES ON PLAQUE VARIANTS OF COXSACKIEVIRUS B5 BY BURST ANALYSES
Authors: Konowalchuk Jack , Speirs Joan I.
Published: February 2010

Propagation of coxsackievirus B5 on cell lines revealed two variants, one that yields small plaques and is stable and another that is large but variable in size. Multiple-burst studies on the large-plaque pool showed the existence of two different population sections. Analysis of a sample from a plaque belonging to the small population section showed a progeny of small plaques while a similar analysis from a plaque in the large population section produced plaques of varying size but whose mean plaque diameter resembled that of the parent culture. Repeated selection for smallness from plaques in the large population section resulted in small plaques and a shift from the large to the small population section. Analysis of the small pool virus on monkey kidney monolayers revealed the presence of a few typical monkey kidney plaques which differed from normal monkey kidney plaques by producing only small plaques on HEp-2 monolayers.
BIOSYNTHESIS OF THE POLYPHENOLIC ACID METABOLITES OF POLYPORUS TUMULOSUS COOKE
Authors: Crowden R. K.
Published: February 2010

Growth and metabolite production by Polyporus tumulosus Cooke were shown to be markedly influenced by (a) the nature of the carbon source, (b) the carbon mitrogen ratio, and (c) the pH of the medium at the time of inoculation. Whereas in some instances growth and metabolite production could be altered independently, production of phenols was more usually correlated with a high growth rate. Further, variations in the conditions of culture were shown to alter the relative proportions of the several phenolic acids as well as the gross yield.The biochemical interrelationships of the metabolites were also investigated. Isotope incorporation experiments demonstrated that these compounds have their biosynthetic origin in the shikimic acid pathway rather than by that of acetate condensation. The primary shunt metabolites were located on two similar pathways and a probable relationship for the secondary shunt metabolites is suggested. The investigation has shown that the well-known fungal metabolite gentisic acid is produced in a biochemical sequence alternative to that usually described for this compound in microorganisms.
UTILIZATION OF AROMATIC HYDROCARBONS BY ARTHROBACTER SPP.
Authors: Stevenson I. L.
Published: February 2010

Bacterial isolates from a number of different soils were screened by growth observation and microscopic examination for Arthrobacter spp. Incidence of arthrobacter in the total population varied, but averaged around 15% in the soils investigated. One hundred and thirty arthrobacter isolates were tested for their ability to utilize aromatic hydrocarbons as their sole carbon source. Seventy-seven percent of these organisms were able to grow on at least two aromatic substrates and many were capable of growth on a wide range of these compounds. Nutritional studies indicated that arthrobacter with simple requirements were able to utilize the greatest number of aromatic hydrocarbons as their sole carbon source. The ability of the arthrobacter to metabolize aromatic compounds is discussed in terms of their possible role in the formation and turnover of residual soil organic matter.
ANTAGONISME DES CHAMPIGNONS DU SOL ENVERS VERTICILLIUM ALBO-ATRUM R. ET B., AGENT DE LA FLÉTRISSURE VERTICILLIENNE DE LA LUZERNE
Authors: Aubé Claude
Published: February 2010

not available
THE STRUCTURE OF PHIALIDES IN PENICILLIUM CLAVIFORME
Authors: Zachariah K. , Fitz-James P. C.
Published: February 2010

The phialides of Penicillium claviforme were examined with the light microscope, and as thin sections, with the electron microscope. Nuclear and spore wall arrangements during conidium production are described. The nuclear configurations are unlike those of normal mitosis. Spore wall formation and nuclear division are associated with the presence of membranous organelles resembling the mesosomes of gram-positive bacteria. The findings are discussed.
THE INFLUENCE OF TIME AND MEDIA CHANGES ON THE INDUCTION AND SUPPRESSION OF β-GALACTOSIDASE SYNTHESIS IN ESCHERICHIA COLI B
Authors: Webb S. J. , Walker Janet L.
Published: February 2010

When cells of Escherichia coli B were grown in a glucose – amino acid medium and then transferred to a minimal medium containing lactose or isopropyl-β-D-thiogalactopyranoside as a sole source of carbon, no induction of β-galactosidase occurred unless one or several amino acids were supplied. Of the amino acids tested, aspartic acid was the most effective and its ability to initiate the synthesis of the enzyme was increased by the addition of arginine. In the presence of these two, or all of the amino acids, there was a lag period of 10 min before enzyme synthesis occurred. The duration of the lag period was unaffected by the addition of nucleic acid bases or succinate to the induction medium. Succinate or glutamate partially inhibited the synthesis of the enzyme, whereas glucose, inositol, or chloramphenicol completely suppressed it. With the exception of that produced by chloramphenicol, inhibition was dependent on the time at which the inhibitor was added. If inhibitors were added after the 10-min lag period, they had no apparent effect until 45 min had elapsed. Cells transferred after 15 min from one induction medium to another displayed for 30 min the induction characteristics of the first medium. It appears that a process occurring during the early 15-min period determines the rate at which enzymes will be synthesized for the next 30 min and that the action of inhibitors is to prevent this process. The process seems to require intact DNA and amino acids and it is suggested that it determines the specificity and quantity of mRNA manufactured.
FURTHER STUDIES ON STEROL STIMULATION OF SEXUAL REPRODUCTION IN PYTHIUM
Authors: Sietsma J. H. , Haskins R. H.
Published: February 2010

The influence of amino acids on the stimulatory activity of cholesterol on the production of oogonia by a species of Pythium is reported. None of the sterols tested was metabolized by the fungus, but the sterols which do affect oogonia production were adsorbed, unchanged by the organism, and probably incorporated in the cell membrane. The organism survived higher temperature when grown on a medium containing cholesterol than when grown on a medium without cholesterol.
THE NATURE OF STAPHYLOCOCCAL BETA HEMOLYSIN: I. MODE OF ACTION
Authors: Wiseman G. M. , Caird J. D.
Published: February 2010

The mode of action of highly punned beta hemolysin derived from the R-1 strain of Staphylococcus aureus has been investigated. Sphingomyelin was absent from lipid extracts of sheep erythrocytes treated with beta hemolysin when compared to normal cells. A correlation was also established between the sphingomyelin content of other erythrocyte species and their sensitivity to beta hemolysin. Further investigations revealed that sphingomyelin is hydrolyzed to yield phosphorylcholine and N-acyl sphingosine. Thus, the mode of action of the beta hemolysin is like that of phospholipase C. Various phosphate compounds other than sphingomyelin, including RNA, glycerophosphate, phenyl-phosphate, phosphatidylethanolamine, and phosphatidylcholine were tested as substrates, but virtually no hydrolysis was observed. In contrast with the results of other workers, R-1 beta hemolysin did not release detectable amounts of carbohydrate from staphylococcal cell walls.
GENETIC STUDIES OF PIGMENTATION OF STAPHYLOCOCCUS AUREUS
Authors: Altenbern Robert A.
Published: February 2010

Exposure of cells of several strains of Staphylococcus aureus to 50 or 100 μg of N-methyl-N′-nitro-N-nitrosoguanidine for 30 to 60 minutes induced large numbers of mutants with pigment content different from that of the parent. By determination of the amount of pigment as related to the optical density of the cells, four to seven classes of pigmentation mutants could be defined. Mutants with pigment content differing from that of the parent could readily be mutated to other pigmentation states and are thus probable point mutations. In contrast, completely white mutants could not be induced by the mutagen to any degree of pigmentation and possibly represent minor deletions or cumulative single-site mutations in the chromosome. Growth of parent strains in media containing acridine dyes occasionally produced a low frequency (0.01%) of white mutants. Mutants differing in pigment content from that of the parent were unable to produce coagulase during growth, although the parent cultures elaborated considerable coagulase under identical conditions.
A PROTEOLYTIC PSEUDOMONAD FROM SKIN LESIONS OF RAINBOW TROUT (SALMO GAIRDNERII): I. CHARACTERISTICS OF THE PATHOGENIC EFFECTS AND THE EXTRACELLULAR PROTEINASE
Authors: Li M. F. , Flemming Carol
Published: February 2010

A fluorescent pseudomonad producing a powerful extracellular proteinase and closely resembling but not identical with Pseudomonas fluorescens was isolated from skin lesions of rainbow trout. Subcutaneous injection of the live organism into healthy frogs caused a condition typical of redleg disease, followed by death, and its subcutaneous injection into healthy rainbow trout caused the formation of large, necrotic, swollen areas filled with fluid. The organism was re-isolated from the deliberately infected animals and histological examinations showed a high degree of destruction of the muscular tissue in the affected areas. The pathogenic effect observed was apparently due to the extracellular bacterial proteinase. Growth of the pseudomonad was insignificant at 3 °C and 37 °C, was slight at 8 °C, and optimal between 15 and 25 °C, and the culture filtrates possessed strong proteolytic activity against casein, hemoglobin, and rainbow trout muscle albumin. The production of this proteinase was dependent on the growth of the organism and the composition of the growth medium.
THE INITIATION OF THE RHIZOSPHERE MYCOFLORA OF DWARF BEAN PLANTS
Authors: Thomas A. , Parkinson D.
Published: February 2010

An attempt was made, using the soil-washing box technique, to obtain detailed information about the initiation of the rhizosphere mycoflora of dwarf bean seedlings.Tabulated information of the fungi isolated from washed non-rhizosphere soil and washed rhizosphere soil from plants during the first 20 days after seed germination is presented together with data of the fungi isolated from the waters in which these soil samples were washed. These data are discussed in relation to previous observations of fungi isolated from rhizospheres by other methods.The results obtained revealed that in the early days after seed germination the rhizosphere mycoflora was qualitatively similar to that of the non-rhizosphere soil. However, a number of distinct differences were discernible between the rhizosphere and non-rhizosphere populations even at these early stages of plant growth, namely that Cylindrocarpon radicicola, Humicola grisea, and a sterile sclerotial form (W1) were isolated with increased frequency from the rhizosphere, whereas Trichoderma viride was consistently isolated less frequently from the rhizosphere than from non-rhizosphere soil.
FORMATION OF SPHEROPLASTS OF MYCOBACTERIUM TUBERCULOSIS BY LYSOZYME IN COMBINATION WITH CERTAIN ENZYMES OF RABBIT PERITONEAL MONOCYTES
Authors: Willett Hilda Pope , Thacore Harshad
Published: February 2010

Spheroplasts of Mycobacterium tuberculosis were formed by culture of the organism in a nutritionally complete medium to which lysozyme and an extract obtained from rabbit peritoneal monocytes were added. The potentiating effect of the factor, or factors, present in the monocyte extract was lost upon prolonged storage at −20 °C or heat at 90 °C for 5 minutes, but was unaffected by dialysis. It was inactive in the presence of fluoride or oxalate. Enzymatic analysis of the monocyte extract showed the presence of lysozyme, acid phosphatase, phospholipase, and trypsin. When acid phosphatase or phospholipase were substituted for the monocyte extract in the lysozyme test system, spheroplast formation was obtained.
EFFET DE L'INOCULATION SUBSÉQUENTE DU VIRUS SV40 SUR LA TRANSPLANTATION DE CELLULES TRANSFORMÉES PAR CE VIRUS
Authors: Dubreuil R. , di Franco E. , Pavilanis V. , Marois P.
Published: February 2010

The inoculation of SV40 virus during the few days following the transplantation of SV40-transformed cells to adult hamsters inhibits the development of the transplanted tumors. The number and the size of the tumors are markedly reduced relative to those developing in control animals inoculated with medium 199.The animals that were resistant to the first transplantation, and those where the tumors were excised, showed an increased resistance to a second transplantation effected after an interval of 8 months.These results are interpreted as supporting the view that the transplantation of virus-transformed cells, and the development of the transplanted tumor, induce complex immunological reactions. The homologous oncogenic virus can be used to modify favorably the balance between cellular and humoral immune reactions conducive to the development of the tumor.
SITES OF "GLYCINE OXIDASE" ACTIVITY IN PROTEUS VULGARIS
Authors: Nermut M. V.
Published: February 2010

The location of glycine oxidase activity in Proteus vulgaris was investigated using potassium tellurite and the technique of ultrathin sections. In 95% of cases, the tellurium deposits were found in the close vicinity of the plasma membrane, presumably at the inner side of it.
PARTIAL CHARACTERIZATION OF SOIL HUMIC ACIDS THROUGH BIODEGRADATION
Authors: Mathur S. P. , Paul E. A.
Published: February 2010

A strain of Penicillium frequentans was successfully employed for partial degradation and characterization of humic acids. Salicyl alcohol and salicylaldehyde were detected in culture filtrates of the fungus utilizing humates under reduced oxygen tension. The enzyme systems involved in the degradation of humic acids were adaptive. The humate-adapted mycelium was capable of metabolizing a number of compounds which occur in soil as products of degradation of lignin, aromatic amino acids, and plant glycosides but not polyphenolic hydrocarbons, resorcinol, and phloroglucinol.
THE PRODUCTION OF 13N2 BY 50-MeV PROTONS FOR USE IN BIOLOGICAL NITROGEN FIXATION
Authors: Campbell N. E. R. , Dular Ram , Lees H. , Standing K. G.
Published: February 2010

An experimental system for the continuous production of radioisotopic nitrogen, 13N2, has been developed using the sector-focused cyclotron at the University of Manitoba. The radioisotope is produced by 50 MeV proton bombardment of 14N2 with powdered melamine as the nitrogen-containing target material. A trap system necessary for the removal of unwanted reaction products is described and details of experimental procedures involving changes in proton beam current and in state of beam focus are presented.Using the radioisotope, a number of microorganisms isolated from sub-Arctic soils of the Fort Churchill region have been examined for their nitrogen fixation potential. Several of these, including a species of Rhodotorula and a species of Pullularia in addition to bacterial forms, have demonstrated nitrogen fixation at a rate comparable with that shown by Azotobacter vinelandii.
POPULATION DYNAMICS OF PYTHIUM APHANIDERMATUM IN OIL CAKE AMENDED SOILS
Authors: Singh R. S. , Pandey K. R.
Published: February 2010

Experiments were carried out to determine the effect of decomposition of oil cakes, used as organic manures in India, on the population of Pythium aphanider-matum in soil. Low quantities (0.1 to 1.0% w/w) of castor and peanut cakes stimulated the growth of the fungus at 20° to 30 °C but in presence of higher quantities of these cakes the growth of the fungus in soil was inhibited. Inhibition was more conspicuous and was caused by lesser amounts of these cakes at high temperatures than at low temperatures. On the other hand, margosa cake (Azadirachta indica) was highly stimulatory to the fungus in all concentrations of 0.1 to 5% at 20°–30 °C, but caused inhibition at 36 °C. Washing of margosa cake with alcohol made it as inhibitory as the other two cakes. It has been suggested that the three cakes affected P. aphanidermatum in soil differently because of their chemical nature and the nature of their decomposition products which may (i) directly suppress the fungus through toxic effect, (ii) stimulate it through nutritional effect, (iii) stimulate or inhibit actinomycetes lytic to the pathogen. Temperature and pH of soil during.decomposition, as well as C:N ratio of the cakes, do not play any major role in the suppression of the fungus.
THE EFFECT OF THE GAMMA ISOMER OF BENZENE HEXACHLORIDE UPON THE MICROFLORA OF SUBMERGED RICE SOILS: II. EFFECT UPON NITROGEN MINERALIZATION AND FIXATION, AND SELECTED BACTERIA
Authors: Raghu K. , MacRae I. C.
Published: February 2010

The effect of applications of γ-benzene hexachloride (γ-BHC) to two submerged tropical soils at rates equivalent to recommended field practice (5 kg/ha) and 10 times this level upon the mineralization of native soil nitrogen was studied. No inhibitory effect on nitrogen mineralization was detected. A significant increase in the amount of nitrogen mineralized was detected in one of the soils over a period of 16 weeks of submergence. Additions of γ-BHC at 6 kg/ha resulted in significant increases in nitrogen fixation in both soils. Populations of anaerobic, phosphate-dissolving bacteria were found to be higher in the two soils when they were treated with γ-BHC at 6 kg/ha.
THE ROLE OF NUTRIENTS AND pH IN REVERSING FUNGISTASIS OF CONIDIA OF TRICHODERMA VIRIDE
Authors: Emmatty Davy A. , Green Jr. Ralph J.
Published: February 2010

Increases in germination of conidia of Trichoderma viride in the presence of soil was demonstrated with 5 of 16 amino acids tested. Only slight increases in germination occurred with selected mono-, di-, and tri-saccharides.Fungistasis of the test conidia was partially annulled when the pH of the spore suspension was adjusted to pH 0.3–0.4 and 1.3–1.4 before addition to agar discs over soil. The pH change was transitory and nearly reached an equilibrium with the soil within 6 to 8 h. Significant changes in the effectiveness of nutrients in reversing fungistasis occurred when the pH of the spore suspension was adjusted before addition to soil. Spore germination increased two- to four-fold with alanine, aspartic, and glutamic acids when the pH was adjusted in the range pH 1.3–1.4 to 5.5–6.5. Glucose increased spore germination only slightly, regardless of pH, but enhanced germination when combined with alanine and aspartic acid. In the presence of glucose, the molar concentration of the amino acids necessary to reverse fungistasis completely or partially was reduced.
EFFECT OF ORGANIC AMENDMENTS ON RHIZOCTONIA AND ACCOMPANYING MICROFLORA IN SOIL
Authors: Henis Y. , Sneh B. , Katan J.
Published: February 2010

The effect of oat straw, green bean plants, and cellulose on the infection index and saprophytic activity of Rhizoctonia, and the effect of chitin, N-supplemented oat straw, and green cotton plants on the infection index, saprophytic activity, and soil microflora was tested. A modified method for counting Rhizoctonia-antagonistic bacteria, actinomycetes, and fungi was developed. A relationship between efficiency of the amendments in decreasing infection index and in suppressing the saprophytic activity of Rhizoctonia was observed at the end of the experimental period. Decrease in infection index and saprophytic activity was accompanied by increase in counts of general and antagonistic soil microorganisms. This increase was especially pronounced in chitin-amended soil. The possible mechanism of the biological control of Rhizoctonia by chitin is discussed.
ISOLATION OF A SERIES OF MENGO VIRUS VARIANTS DIFFERING IN SENSITIVITY TO POLYANIONS
Authors: Campbell James B. , Colter John S.
Published: February 2010

The isolation of six distinct new plaque variants from pools of S- and M-Mengo (small- and medium-plaque variants respectively) is described. The size of plaques produced in L cell monolayers under nutrient agar by five of the six new variants is strongly inhibited by the addition to the overlay of dextran sulfate of molecular weight 500,000. The sixth, although similar to L-Mengo in its virulence to mice and in having plaques that are almost unaffected by the addition of protamine or dextran sulfate to the overlay, can be distinguished from the latter by the larger and more uniform plaques it produces. The marked heterogeneity in the size of plaques produced by L-Mengo appears to be an inherent property of this variant, since all attempts to isolate other plaque variants from L-Mengo pools have been unsuccessful.The intraperitoneal LD50's of all six new variants in 14- to 16-g mice was determined. There is no complete correlation between the virulence of these variants and their sensitivity to inhibition by dextran sulfate.
PHENOLS AS INTERMEDIATES IN THE DECOMPOSITION OF PHENOXYACETATES BY AN ARTHROBACTER SPECIES
Authors: Loos M. A. , Roberts R. N. , Alexander M.
Published: February 2010

Decomposition of 2,4-dichlorophenoxyacetate (2,4-D) by a soil arthrobacter was studied using the technique of sequential induction. Compounds oxidized rapidly and without a lag by 2,4-D-grown cells, but slowly or not at all by citrate-grown cells, included 2,4-D, 2- and 4-chlorophenoxyacetate, 3,5-dichloro- and 4-chloro-catechol, catechol, 2,4-dichlorophenol, and 2- and 4-chlorophenol. The manometric data suggested that phenols and catechols were intermediates in the degradation of phenoxyacetates. Resting cells failed to accumulate chlorine-substituted phenols during the metabolism of halogenated phenoxyacetates, apparently because the phenols were oxidized as readily as they were formed. However, 2,4-D-induced cells contained enzymes which acted upon phenoxyacetate and 4-hydroxyphenoxyacetate, but these cells did not metabolize phenol and hydroquinone. Suspensions of such bacteria, but not citrate-grown cells, converted phenoxyacetate and 4-hydroxyphenoxyacetate almost completely to phenol and hydroquinone, respectively. The results indicate that the Arthrobacter sp. degrades 2,4-D via 2,4-dichlorophenol, and 2- and 4-chlorophenoxyacetate via 2- and 4-chlorophenol, respectively. The results also demonstrate a new technique for obtaining high yields of an intermediate in a metabolic sequence.
CARBOHYDRATE METABOLISM IN HYDROGENOMONAS EUTROPHA
Authors: Cook David W. , Tischer Robert G. , Brown Lewis R.
Published: February 2010

Fructose was found to be the only carbohydrate of the 12 tested that can be utilized as a carbon and an energy source by Hydrogenomonas eutropha although glucose, ribose, xylose, and arabinose were isolated from the spent medium on which this organism had grown. This organism can adapt to fructose under an air atmosphere as well as under an H2-O2-CO2atmosphere.Fructose-grown cells of H. eutropha oxidize fructose almost completely to CO2and water whereas autotrophically grown cells exhibit a respiratory quotient of about one-half of the theoretical value.H. eutropha grew on "autoclaved glucose" medium although the cells failed to oxidize glucose in resting cell experiments. Apparently, these cells were growing at the expense of fructose formed from the glucose during autoclaving.
THE EXTRACELLULAR PROTEASE FROM PSEUDOMONAS AERUGINOSA EXHIBITING ELASTASE ACTIVITY
Authors: Johnson Gerald G. , Morris Joanne M. , Berk Richard S.
Published: February 2010

The extracellular proteases of a highly proteolytic culture of Pseudomonas aeruginosa grown on tryptone–glucose agar were examined in vitro and in vivo. The greater part of the activity was found to consist of a protease exhibiting elastase activity. Through a series of chemical and column (DEAE-Sephadex, pH 8.6) steps, the elastase fraction was isolated and purified 100-fold with an approximate recovery of 68%. Dermonecrosis was obtained in rabbits with the partially purified elastase, but not with a toxic, major protein component free of proteolytic activity which was obtained prior to the elution of the elastase fraction. Purified protease (LD50was equivalent to six protease units) and the non-proteolytic fraction elicited lethality within 24–48 h when singly administered intraperitoneally to mice in concentrations of 50–100 μg protein, whereas crude preparations exhibited little or no lethality below 600–1000 μg protein per mouse. Intraperitoneal administration of eight or more protease units to mice resulted in death within 1–2 h with the concomitant appearance of massive abdominal hemorrhage, intestinal lesions, and numerous pin-point blanched areas on the liver surface; whereas no significant gross pathological changes were noted in mice killed by lethal doses of the non-enzymatic protein fraction.