bluuebunny/crossref_metadata_2025 huggingface dataset:
The accumulation of phenolic acids and coproporphyrin by iron-deficient cultures of Bacillus subtilis
Authors: Peters W. J. , Warren R. A. J.
Published: February 2010

Phenolic acids started to accumulate before coproporphyrin in cultures of B. subtilis grown under conditions of iron deficiency. If hemin synthesis was reduced or prevented, both phenolic acid accumulation and the iron-uptake capacity of the cells were decreased. A mutant strain unable to synthesize hemin accumulated phenolic acids only if the culture medium was extracted with hydroxyquinoline to remove residual iron. A mixture of iron and 2,3-dihydroxybenzoic acid was more effective than iron alone in reducing coproporphyrin accumulation by iron-deficient cultures. It is suggested that phenolic acids are produced by B. subtilis to solubilize the iron in the medium; under iron deficiency the biosynthetic pathway for phenolic acids is derepressed so that residual iron in the medium will be made available to the cell as the phenolic acid: iron complex.
Metabolic activity of acetate-grown Bacillus megaterium KM
Authors: Donawa A. , Inniss W. E.
Published: February 2010

Acetate-grown Bacillus megaterium KM possessed high isocitrate lyase and malate synthase activity as compared to glucose-grown cells. Chloramphenicol prevented the increase in isocitrate lyase activity when cells were transferred from glucose to acetate media, indicating that such an increase in activity was probably due to de novo protein synthesis.The affinity of the substrate, isocitrate, was greater for isocitrate dehydrogenase than for isocitrate lyase. Phosphoenolpyruvate was found to inhibit isocitrate lyase non-competitively. The concerted action of glyoxylate and oxaloacetate was capable of inhibiting isocitrate dehydrogenase. The role such factors play in the balancing of the tricarboxylic acid cycle and the glyoxylate pathway in the microorganism is considered.
The correlation between change in absorbancy, calcium uptake, and cell-bound nisin activity in Streptococcus lactis
Authors: Hurst A. , Kruse H.
Published: February 2010

The absorbancy of cell suspensions of Streptococcus lactis increased immediately when the suspensions were incubated in a solution of 50 mM (pH 7.2) tris buffer, 100 mM CaCl2, and 140 mM glucose. The reaction was sensitive to NaF, carbonyl cyanide m-chlorophenylhydrazine, valinomycin, and Na-iodoacetate and insensitive to ouabain, dinitrophenol, n-ethylmaleimide, and malonic acid. During the optical reaction the cells incorporated 45 Ca2+ and lost nisin bioassay activity. When Ca2+ was omitted there was a diminished optical reaction and bioassayable nisin was lost only temporarily. With Ca2+ present but glucose omitted or in the complete reaction solution plus iodoacetate, the optical reaction, incorporation of 45 Ca2+, and inactivation of nisin were all stopped. Hot acid-soluble proteins extracted from cells after the optical reaction gave electrophoretic patterns which differed significantly from the controls but the peak areas of the nisin-like proteins remained unchanged. The bioassay activity was one-sixth that of the control. Cell-free solutions of purified nisin did not interact with CaCl2. It is suggested that in the presence of glucose living cells incorporate calcium, which leads to a configurational change of the cells which is measured by the optical reaction, and that this configurational change is associated with nisin inactivation.
Cytochromes in a cyanide-resistant strain of Bacillus cereus
Authors: McFeters Gordon A. , Wilson David F. , Strobel Gary A.
Published: February 2010

A highly cyanide resistant strain of Bacillus cereus has been studied. The cell respiration was unusually resistant to inhibition by both cyanide and azide. The cyanide resistance could be further increased by growing the cells in the presence of 10−3 M cyanide. The electron-transport system of this strain of B. cereus contained flavoprotein, cytochrome b, and a cytochrome a type of oxidase. Growth in the presence of cyanide caused a marked increase in the amount of cytochrome b and of the oxidase. The oxidase was inhibited by CO, this inhibition is photoreversible, and the action spectrum was indistinguishable from that of cytochrome a3 and a.
Inhibition of germination of chlamydospores of Phytophthora cinnamomi by some antimicrobial agents in Phytophthora selective media
Authors: Mircetich Srecko M.
Published: February 2010

Mycelia and chlamydospores of Phytophthora cinnamomi showed differential sensitivity to certain antimicrobial agents in pimaricin–vancomycin (PV), pimaricin–penicillin–polymyxin (3P), and Kerr's modified (KM) selective media. Recovery of P. cinnamomi on PV and KM was 100% from colonized fiberglass that was buried in natural soil for 5 days, and contained viable mycelia, but the recovery was only 36% and 10% after 60 days of incubation when mycelia were lysed and fiberglass contained only chlamydospores. Pimaricin at 100 p.p.m. as used in PV and 3P inhibited germination in 43% of chlamydospores but at 10 p.p.m. was not inhibitory. Polymyxin (50 p.p.m.), a component of 3P, was lethal to chlamydospores, while penicillin (50 p.p.m.) and vancomycin (200 and 300 p.p.m.) had no effect on germination. Streptomycin (50 p.p.m.) and rose bengal (60 p.p.m.), when used together, as in KM, were lethal to over 90% of chlamydospores but had no effect when used separately in this medium. However, toxicity of rose bengal to chlamydospores was intensified by undetermined component(s) of V-8 juice broth, by citric acid – Na2HPO4 buffer, or by exposure of media containing rose bengal to daylight. In the development of selective media, the importance of evaluating the toxicity of prospective antimicrobial agents to all stages of the fungus to be isolated or cultured, as well as the need to study possible synergism among various components of the media, are discussed.
Diacetyl production by Propionibacterium shermanii in milk cultures
Authors: Lee S. Y. , Vedamuthu E. R. , Washam C. J. , Reinbold G. W.
Published: February 2010

Diacetyl production by propionibacteria in milk cultures was studied using a previously described sensitive method specific for diacetyl. Twenty-four strains belonging to six Propionibacterium species were included in the study. A strain of P. shermanii that produced relatively large amounts of diacetyl in milk was chosen for investigations on factors affecting diacetyl production.Accumulation of the diketone in milk cultures was greater at 21 C than at 32 or 37 C although the rate of production of the compound was greater at the higher temperatures. Rapid cooling after incubation stabilized the diacetyl levels in milk cultures, and prolonged refrigerated holding caused an increase in the concentration of the flavor compound. The dicarbonyl production was greatly affected by the pH of the culture medium, the most favorable range being 4.0 to 4.5. In mixed culture study using a homo-fermentative Streptococcus lactis in combination with the P. shermanii strain, diacetyl production by the latter was greatly enhanced by the rapid pH depression brought about by the streptococci. Diacetyl reductase assays on cell-free extract preparations from the P. shermanii strain showed little or no activity.
Characterization of some of the acidic products of glucose fermentation by a large-cell strain of Escherichia coli
Authors: Thayer Donald W.
Published: February 2010

Fermentation products of a large-cell strain of Escherichia coli P6 F−ade−T1s and its small-cell parent strain 82/r were examined for acidic carbonyl compounds, ethanol, formic acid, and lactic acid. This large-cell strain is unusual in that there is evidence which indicates that it is a stable large-cell, homozygous diploid. Significantly larger amounts of pyruvic and formic acid were found in media in which E. coli P6 had grown anaerobically with glucose as the carbon source, whereas lactic acid was the predominant product measured in the media in which E. coli 82/r had grown. Under conditions which allowed all available substrate to be fermented during growth of E. coli P6, 82/r, and two large-cell recombinants R11 ade+T1r and R19 ade+T1r a significant amount of residual pyruvic acid was found only in the cultures of E. coli P6 F−ade−T1s. These results were interpreted to indicate that the effect of pyruvate accumulation was not due to the concentration of glucose, the cell size, or the doubled deoxyribonucleic acid content of the large-cell strains. Several other acidic carbonyl compounds were partially characterized. Evidence is presented to substantiate the concept of a genetic defect in E. coli P6 F−ade−T1s whose expression is linked to either the large-cell state and (or) to its doubled content of deoxyribonucleic acid.
The effect of myxin on membrane synthesis in Escherichia coli
Authors: Stevenson I. L.
Published: February 2010

When actively growing cells of Escherichia coli 15T− were treated with a high concentration of myxin (5 μg/ml) cell division was inhibited and further growth ceased. After 45 min exposure to the antibiotic, vacuolated areas appeared as the result of intracellular ramifications of the plasma membrane. The amount of membrane involved suggested continued synthesis of this structure in the presence of myxin. Radioisotope studies with 14C-acetate revealed a greater incorporation of the label in isolated envelope fractions of the cells in the presence of myxin than in normally growing cells. It would appear that with 5 μg/ml myxin, membrane synthesis continues while other biosynthetic systems responsible for growth and cell division are effectively inhibited.
Selective inhibition of certain enteric bacteria by selenite media incubated at 35 and 43 C
Authors: Greenfield J. , Bigland C. H.
Published: February 2010

Selenite broth (SB) is a useful enrichment medium for isolating certain salmonellae and arizonae from specimen materials contaminated with competitive bacteria. Pure cultures of pseudomonas, proteus, and some coliform strains were suppressed more markedly by SB media containing additional selenite than the salmonellae and arizonae tested. Some very closely related organisms showed conspicuously different results and whereas many serotypes of Escherichia coli were inhibited, others flourished in the test environments. Selenite media were more toxic to some salmonellae than to others, and Salmonella choleraesuis, S. gallinarum, S. pullorum, and S. typhi did not grow well, especially at 43 C. Selenite broth incubated at 43 C proved to be more toxic to all test cultures than incubation at 35 C, but in general the salmonellae and arizonae were inhibited less than the extraneous bacteria with which they are often associated.
On the infectivity of the Sindbis virus nucleocapsid
Authors: Dobos P. , Faulkner P.
Published: February 2010

The nucleocapsid fraction derived either from Sindbis virions or from infected cell cultures was studied with respect to its ability to adsorb to susceptible cells as well as to initiate stages in viral replication. Neither preparation was adsorbed to BHK 21 cells under conditions where virion adsorption could be demonstrated. In addition parental RNA from virions was shown to be converted to an RNAase-resistant 16–20 S form, whereas no evidence for the penetration and conversion of RNA present in viral cores was observed. These studies emphasize the role of envelope proteins in facilitating entry of intact virus into susceptible cells.
The mechanism of iron uptake in Bacillus subtilis
Authors: Peters W. J. , Warren R. A. J.
Published: February 2010

A variety of phenolic compounds and hydroxamic acids reduced or prevented phenolic acid and coproporphyrin accumulation by iron-deficient cultures of Bacillus subtilis, but only if they were added to cultures with levels of iron which alone did not prevent accumulation. The compounds also increased iron uptake by iron-deficient cultures and norma) cultures. When radioactive catechol or 2,3-dihydroxybenzoic acid was used to increase iron uptake by iron-deficient cells, only very low levels of radioactivity remained associated with the cells. It is suggested that B. subtilis produces phenolic acids to solubilize iron; that other phenolic compounds or hydroxamic acids may substitute for the phenolic acids produced by B. subtilis; that the iron: phenolic acid complex does not enter the cell; and that the iron is removed from the complex at the cell surface and taken into the cell by an energy-dependent active transport system.
Development and statistic evaluation of a plaque assay for the virus of epizootic hemorrhagic disease of deer
Authors: Willis N. G. , Corey P. N. , Campbell J. B. , Macpherson L. W.
Published: February 2010

A plaque assay system for the virus of epizootic hemorrhagic disease of deer in the WI-2 subline of BHK-21 cells is described. The system uses infection of the cells in suspension before growth as a monolayer under supplemented Leibovitz L-15 medium incorporating gum tragacanth. Crude cell lysates were initially used as a source of virus for the assay system. Since 90% of the infectious virus titer was lost on removal of cell debris by centrifugation, a statistical analysis of the validity of using uncentrifuged lysates for plaquing was carried out. Data showed that, except at low virus concentrations, the plaque counts were consistent with a negative binomial rather than a Poisson distribution. When the cell lysates were clarified by low-speed centrifugation, plaque count variation followed a Poisson distribution even at high mean plaque counts. There was no appreciable overlap error for plaque counts up to at least 100 per 60-mm dish. Using both clarified and unclarified cell lysates, a good linear relationship was found to exist between plaque numbers and relative virus concentration.
Interaction of interferon with cells: the relationship of cell-associated interferon and antiviral activity
Authors: Sheaff Edward T. , Stewart Robert B.
Published: February 2010

Studies of the effect of interferon on the growth of Sindbis virus in cultures of chick embryo cells have shown that interferon is taken up by cells and that such uptake must occur before antiviral activity is observed. Evidence is presented here that the quantitative expression of antiviral activity is dependent on the amount of interferon that becomes cell associated.
Interaction of interferon with cells: the synthesis of an interferon-induced protein
Authors: Sheaff Edward T. , Stewart Robert B.
Published: February 2010

Double labeling experiments were performed in an attempt to demonstrate an interferon-induced material. An acid-insoluble fraction was obtained that demonstrated considerable enrichment with the isotope used to label interferon-induced cells. This enrichment was found to coincide with the characteristics of induction in terms of its suppression by inhibitors of mRNA and protein synthesis. An attempt was made to demonstrate specific binding of the enriched material with interferon-utilizing displacement in a sucrose gradient. Binding of interferon to the isotope enriched fraction was obtained but the specificity was not absolute. It is suggested that this substance is either involved in interferon transport or in the expression of interferon antiviral activity.
Alkaline phosphatase localization and spheroplast formation of Pseudomonas aeruginosa
Authors: Cheng K. -J. , Ingram J. M. , Costerton J. W.
Published: February 2010

Pseudomonas aeruginosa cells grown in the presence of low levels of inorganic phosphate contain an inducible alkaline phosphatase system. The enzyme has been localized by electron microscopic techniques in the region between the cytoplasmic membrane and the tripartite layer of the cell wall, i.e. the periplasmic space. No deposits of lead salts are observed upon examination of either uninduced cells or cells in which the enzyme has been completely removed by 0.2 M magnesium washing. Samples of cells which were treated with glutaraldehyde before enzyme localization studies show cell wall deposition of lead salts which could give rise to the erroneous conclusion that the alkaline phosphatase was located in the tripartite layer. Cytochemical and biochemical studies are presented which show that discontinuities within the cell wall are insufficient to account for the release of this periplasmic enzyme and that dissociation by a divalent metal, increased pH, or both is required. As a consequence of this study it was possible to prepare true spheroplasts of P. aeruginosa.
Effect of some culture conditions on the production of indole-3-acetic acid and a gibberellin-like substance by Azotobacter vinelandii
Authors: Lee M. , Breckenridge C. , Knowles R.
Published: February 2010

Ethyl acetate extracts of concentrated culture supernatants were studied using thin-layer and paper chromatography in four solvent systems and Avena, Lactuca, and Hordeum bioassays. Indole-3-acetic acid (IAA) was synthesized between 3 and 6 days of incubation and remained maximal at 8 × 10−8 M from 7 to 40 days. A possible precursor, tentatively identified as 3-indoleacetamide (IAM), was present during the early period of IAA production. Relatively more IAA was produced in shaking than in stationary culture and in nitrogen-free than in ammonium-containing medium.A gibberellin-like substance which had some similarity to GA3 was detected but could not be reproducibly demonstrated. It occurred in 18- and 40-day-old cultures at a concentration of 3 × 10−3 μg GA3-equivalent/ml but was never seen in cultures of 12 days or less.
Characterization of mycoplasmas isolated from the great apes
Authors: Cole Barry C. , Ward John R. , Golightly-Rowland Laura , Graham Charles E.
Published: February 2010

Nine adult female chimpanzees, five adult female orangutans, and three young female gorillas were cultured for mycoplasmas. All animals were found to harbor at least one species of mycoplasma and some as many as four. On the basis of physiological and serological characteristics mycoplasmas closely related or identical with M. hominis, M. salivarium, and M. orale types 1 and 2 were identified. The M. hominis strains which were restricted to the chimpanzee comprised two serologic subgroups but were physiologically homogeneous. The M. salivarium strains were physiologically and morphologically heterogeneous, with both lipolytic and non-lipolytic strains being isolated from the salivas of all three primate species. All strains of M. salivarium were closely related serologically. In addition to the above species, three unidentifiable types were encountered. Type 1 strains were isolated from the vaginas of two chimpanzees. The type 2 strain, which shared up to three antigenic components with various human mycoplasmas, was isolated from the oropharynx of a chimpanzee. The type 3 strains constituted the only mycoplasma species isolated from the orangutan vagina.
Allosteric interaction of D-glutamate with the glutamate dehydrogenases of Neurospora crassa
Authors: Kapoor M. , Grover A. K.
Published: February 2010

D-Glutamate inhibits the two glutamate dehydrogenases of Neurospora crassa. Kinetic studies of inhibition are suggestive of cooperativity in binding to both the enzymes.
Exogenous carbon and nitrogen requirements for chlamydospore germination by Fusarium solani: dependence on spore density
Authors: Griffin G. J.
Published: February 2010

Chlamydospores were formed on germ tubes of macroconidia of F. solani after germination at 3 × 105 conidia/ml in an inorganic salt solution (pH 5.7) containing glucose (40 μg C/ml) plus NH4Cl (2.6 μg N/ml), and at 3 × 103 conidia/ml in salt solution containing no glucose or NH4Cl. After 5 days, chlamydospores formed in the low conidial density system required an exogenous source of carbon for high germination, whereas chlamydospores formed in the high conidial density system required both exogenous carbon and nitrogen for high germination. Chlamydospores formed in the high conidial density system did not require exogenous nitrogen for high germination when the spore density (chlamydospores plus some ungerminated conidia) was reduced from 3 × 105 to 3 × 104 spores/ml; high germination was observed at 3 × 103 spores/ml in the absence of both exogenous carbon and nitrogen.
Synchronous growth of Staphylococcus aureus induced by amino acid and thymine starvation
Authors: Gutman Hilary , Pattee P. A.
Published: February 2010

Synchronous growth of a thymine-dependent strain of Staphylococcus aureus occurred when thymine was added to a culture previously starved of required amino acids, and then starved for thymine in the presence of required amino acids.
The effect of gamma radiation on carnation mottle virus in crude Dianthus barbatus sap
Authors: Kemp W. G.
Published: February 2010

The infectivity of carnation mottle virus in crude and clarified sap was not completely eliminated after exposure to 1000 krad of gamma irradiation. In clarified sap, the virus was more sensitive to doses of gamma radiation than in crude sap. Loss in infectivity of either of the virus suspensions was not correlated with a corresponding loss in antigenic activity.
The fatty acid composition of Dactylaria and Scolecobasidium
Authors: Sumner J. L. , Evans H. C.
Published: February 2010

The fatty acid composition of some thermotolerant strains of Dactylaria gallopava isolated from coal spoil tips has been compared with that of the type strain of D. gallopava, the original isolation of which was from diseased turkey poults. In addition, the fatty acids of the mesophilic fungi Dactylaria ampulliforme and Scolecobasidium spp. were analyzed. The scolecobasidia and D. gallopava had the same qualitative fatty acid pattern, though quantitatively there were differences, the scolecobasidia having more highly unsaturated lipids than D. gallopava. D. ampulliforme contained the triply unsaturated γ-linolenic acid and eicosatrienoic acid, and in this respect differed from the scolecobasidia and D. gallopava, which appeared unable to synthesize trienoic acids.
Control of serine biosynthesis in Micrococcus lysodeikticus: inhibition of phosphoglyceric acid dehydrogenase
Authors: Nelson Jr. J. D. , Naylor H. B.
Published: February 2010

In Micrococcus lysodeikticus, the first enzyme of serine biosynthesis, phosphoglyceric acid dehydrogenase, was found to be inhibited by L-serine, adenosine-5′-monophosphate (AMP), the reduced form of nicotinamide adenine dinucleotide, and less strongly by glycine. Inhibition by serine was increased by the incorporation of glycerol or divalent cations into cell-free extracts, and was decreased by ammonium sulfate fractionation. Inhibition by AMP was not modified by glycerol or ammonium sulfate fractionation but was increased by added divalent cations. The addition of Ca2+ ions resulted in a greater increase in serine inhibition than Mg2+, Mn2+, or Zn2+ ions. Serine and AMP inhibitions approached maxima in extracts containing about 30 mM Ca2+. The synthesis of labeled L-phosphoserine from 14C-3-phosphoglyceric acid was also inhibited by serine and AMP.
Characterization of a micrococcus which enhances the cellulolytic activity of Trichurus cylindricus
Authors: Smith R. E. , Neudoerffer T. S.
Published: February 2010

A bacterial contaminant from a cellulase-producing culture of Trichurus cylindricus was subjected to physiological and biochemical tests, and identified as a member of the genus Micrococcus, subgroup 6 (Baird-Parker). It appeared either to stimulate cellulase production by the fungus, or to increase cellulase activity. The amino acid and protein content of the Micrococcus suggested that it might be useful as a feed supplement. In a preliminary trial, rats accepted freeze-dried cells as a partial source of energy, and grew at a normal rate. No toxic effects of the diet were noted.
Naphthylamidases of Sarcina lutea
Authors: Behal Francis J. , Carter Rita T.
Published: February 2010

The naphthylamidase isozyme complement of Sarcina lutea was studied. Gel filtration yielded two fractions, Sephadex I and Sephadex II. Sephadex I contained one enzyme generally resembling leucineaminopeptidase. Sephadex II, upon ion exchange chromatography, yielded three isozymes, A, B, and C. These three were characterized with respect to molecular weight, substrate specificities, and effects of hydrogen ion concentration, EDTA, and divalent cation on reaction velocity. The molecular weights are 8.0 × 104, 8.2 × 104, and 9.0 × 104 respectively. Isozymes A and B are neutral naphthylamidases and preferentially catalyze the hydrolysis of alanine-β-naphthylamide (βNA), whereas isozyme C is a basic naphthylamidase and preferentially catalyzes the hydrolysis of lysine and arginine-βNA. The pH optima for the isozymes are 7.6, 7.6, and 6.7, respectively. All of the isozymes are sensitive to the effects of EDTA. Divalent cations activate the enzymes and reverse inhibition caused by EDTA.
The regulation of phenolic acid synthesis in Bacillus subtilis
Authors: Walsh B. L. , Peters W. J. , Warren R. A. J.
Published: February 2010

Formation of the enzymes synthesizing 2,3-dihydroxybenzoic acid (DHB) in Bacillus subtilis is repressed by iron. DHB does not appear to be involved in regulating its own biosynthesis. Hemin may be involved in regulating DHB synthesis. DHB synthetase is inhibited by several m-substituted benzoic acids. The inhibitors do not affect the growth rate of B. subtilis and DHB appears not to be necessary for growth under the conditions used. Inhibition of DHB synthesis during growth under iron-deficient conditions reduces the iron uptake capacity of B. subtilis.
The fine structure of Verticillium dahliae Kleb. colonizing cellophane
Authors: Griffiths D. A.
Published: February 2010

Hyphae of Verticillium dahliae Kleb. penetrated cellophane membranes supported on a sucrose-rich medium. Vesicular production be penetrating hyphae was thought to be concerned with cell wall synthesis and the production of extramycelial enzymes which facilitated colonization. After complete dissolution of the membrane hyphae underwent a process of degeneration.
Comparison between the antigenic components extracted from virulent and avirulent strains of mycobacteria
Authors: Turcotte R. , Boulanger R. P.
Published: February 2010

The antigenic relationship between virulent and attenuated or avirulent human, bovine, and avian strains of mycobacteria has been studied with rabbit immunesera against fractions obtained from mechanically disintegrated bacilli. The antigenic comparison was carried out by Immunoelectrophoresis after cross-absorption of antisera. It was shown that the human virulent strain H37Rv, the bovine virulent strain Ravenel, and the avian virulent strain Sheard had at least two antigens which were not detected in the related attenuated or avirulent strains. Furthermore, these additional antigens were found to be different from strain to strain.The antigenic comparison between human, bovine, and avian strains of mycobacteria revealed that fewer antigenic differences existed between human and bovine than between human or bovine and avian strains.
Inhibition of the growth of Helminthosporium carbonum by L-cysteine
Authors: Allen Edward H. , Hussey Griscelda G.
Published: February 2010

L-Cysteine (1.21 mg/ml) inhibited the linear growth of Helminthosporium carbonum 22% at pH 5.5 and 60% at pH 4. The increased toxicity with increasing acidity was attributed, in part, to the increase in the concentration of the cysteine cation [HS—CH2—CH(NH3+)—COOH]. In the presence of chlorogenic acid (1.77 mg/ml), L-cysteine (1.21 mg/ml) was more toxic than when tested alone. This increased toxicity was due to the acidity of chlorogenic acid, which had little or no fungitoxicity when tested alone. Chlorogenic acid did not increase the toxicity of L-cysteine when the increased acidity was neutralized with base. L-Cysteine at 0.6 mg/ml and 0.3 mg/ml inhibited the growth of H. carbonum, respectively, 32% and 10% at pH 4.5, and 5% and 1% at pH 5.5. Since L-cysteine is toxic only at relatively high concentrations, it appears doubtful whether this amino acid contributes significantly to the fungitoxicity of potato peel extracts.
Degradation of rutin by Aspergillus flavus. Purification of the dioxygenase, quercetinase
Authors: Oka T. , Simpson F. J. , Child J. J. , Mills Sister Cecily
Published: February 2010

Evidence is presented that a single enzyme, quercetinase, is responsible for the degradation of quercetin by Aspergillus flavus to yield carbon monoxide and a depside, 2-protocatechuoylphloroglucinol carboxylic acid. A procedure for the isolation of the dioxygenase as a homogeneous protein is described. The most purified preparation degraded 10 800 μmoles of quercetin/h mg protein and was homogeneous as judged by ultracentrifugation and by electrophoresis. The molecular weight was determined as 111 000 + 4000. Km values for quercetin and oxygen as substrates were 5.2 × 10−6 M and 1.2 × 10−4 M respectively. The enzyme is a glycoprotein containing 27.5% carbohydrate and the amino acid composition is presented.
The synchronization of Bacillus subtilis by the relaxation of a division control system
Authors: Paulton R. J. L.
Published: February 2010

Synchronously dividing cultures of Bacillus subtilis were obtained by harvesting cells from the stationary phase and reincubating them in fresh medium. It was discovered that the first division period was not necessarily synchronous, but when the first synchronous division occurred it involved a reduction in septation. These findings suggested that cell synthesis was directed to more than the forthcoming division, and that synchronization involved a subsequent division and a change in the cell division control mechanism.
The identification of strains of tobacco mosaic virus from tomato crops in Southern Ontario
Authors: Fletcher J. T. , MacNeill B. H.
Published: February 2010

Two hundred and nine isolates of tobacco mosaic virus (TMV) were collected from the spring and fall greenhouse crops, and the field crop of Southern Ontario. Strains of the virus were identified on a series of differentials which included Pelham's four tomato lines heterozygous for the genes Tm-1, Tm-2, Tm-1 + Tm-2, and Tm-22 respectively. There were 164 isolates of TMV strain 0, 15 of strain 1, and 30 which were intermediate in character. Strains 2 and 1.2 were not found. The reactions of a number of lines of Tm-1 differentials of independent origin were compared and found to vary with some virus isolates. The recently introduced TMV-tolerant cultivar Vendor did not have any marked influence on the TMV strain situation in the commercial greenhouse crops either to reduce strain 0 types or to bulk-up strain 1 types which might find this cultivar a congenial host.
Effect of irradiation temperature in the range −196 to 95C on the resistance of spores of Clostridium botulinum 33A in cooked beef
Authors: Grecz N. , Walker A. A. , Anellis Abe , Berkowitz D.
Published: February 2010

Cans of ground cooked beef, inoculated with 106 or 108 spores per can of Clostridium botulinum 33A, were irradiated with 60Co gamma rays at a series of 14 temperatures ranging from −196 to 95C. The higher inoculum level required higher sterilizing doses. The D values, computed on the basis of recoverable C. botulinum, were independent of the inoculum level, and showed that spore resistance progressively decreased with increasing temperature. A statistical analysis of these data disclosed that the change in D values from −196 to 65C followed equally well a quadratic, exponential, or linear best-fit plot; above 65C radiation death was much more rapid. An equation was derived from the linear plot to predict D values for any desired temperature between −196 and 65C. Calculations of Ea and Q10 values, based on the linear curve, indicated a very small thermodynamic effect on radiation kill. An Arrhenius analysis of the temperature effect suggested that there was no simple physicochemical mechanism occurring in the inoculated beef pack which might explain the change in spore kill as a function of temperature. Theoretical commercial radiation processes for beef, based on the 12D concept and strain 33A spores, are presented for several easily controlled irradiation temperatures.
Characterization of a canine adenovirus hemagglutinin
Authors: Marusyk R. G. , Yamamoto T.
Published: February 2010

The hemagglutinating activity of the canine adenoviruses was found to be more than 80% associated with both the intact and incomplete ('empty') virus particles, the remaining complete hemagglutinating activity being associated with a naturally occurring soluble penton dimer structure. Trypsin treatment of the hemagglutinin – red blood cell complex and receptor-competition experiments, using purified fiber component to block the receptor sites on the red blood cells, indicate that there are different receptors for infectious canine laryngotracheitis (ICL) virus and infectious canine hepatitis (ICH) virus.The ICL adenovirus was found to hemagglutinate human and rat erythrocytes but not those of a number of other animal species. Using human group 'O' erythrocytes the ICL virus associated hemagglutinating activity was found to occur over a wide range in temperature and pH, and certain purification procedures, such as fluorocarbon treatment and sonic oscillation, were found to inactivate the hemagglutinin rapidly.
The fluorescent staining of a mycobacteriophage (C2) nucleic acid
Authors: Menezes Jose
Published: February 2010

By using the acridine orange staining technique a green fluorescence, characteristic of double-stranded nucleic acid, can be observed with purified preparations of mycobacteriophage C2 and its extracted nucleic acid. DNAse-treated samples do not show this fluorescence, which leads to the conclusion that this fluorescence is associated with phage DNA. Examination of preparations of phage grown in the presence of acridine orange supported these results.
The iron-uptake system of Bacillus subtilis
Authors: Walsh B. L. , Warren R. A. J.
Published: February 2010

Iron uptake in Bacillus subtilis is mediated by a system which is specific for, and repressed by, iron and which requires an energy supply and is dependent upon the integrity of the cell membrane.
The temperature dependence of mortality rate in starved yeast cells
Authors: Matsumoto Shinji
Published: February 2010

The thermal inactivation of stable and unstable (persistent lethal sectoring) lines of yeast was investigated at various temperatures. The temperature dependence of mortality rate was adequately described by the first-order chemical reaction formula. A semilog plot of temperature vs. life time of the stable line appeared as a straight line. On the other hand, that of the unstable line had two components: one had the same activation energy as the stable line and the other one had a different lower value. This new component may have originated in a mutated protein and caused the instability.
Effect of membrane-active antibiotics on motility and 42K permeability of Pseudomonas fluorescens
Authors: Faust Maria A. , Doetsch R. N.
Published: February 2010

Valinomycin, monactin, and nonactin were found to affect the motility of Pseudomonas fluorescens. Cells "loaded" with 42K rapidly exchanged it with K+ when exposed to the above compounds, and uptake of such unlabeled K+ resulted in a net increase in total potassium content. Hydrogen ions also moved rapidly into the antibiotic-treated organisms, and both potassium and hydrogen ion permeability were used as measures of membrane integrity. Alteration of membranes by these antibiotics suggests a possible relationship between this and diminution of flagellar activity. Membrane-active antibiotics may be useful agents for studying membrane-mediated transformations of chemical into mechanical energy using motile bacteria as model systems.
Susceptibility of the cell walls of some yeasts to lysis by enzymes of Helix pomatia
Authors: Brown Joseph P.
Published: February 2010

Cells of Torulopsis glabrata, Candida albicans, and Saccharomyces cerevisiae were assayed during different phases of their growth cycles to compare their susceptibility to the action of helicase, an extract from Helix pomatia. Substantial differences were found in their reaction to the enzymes. The susceptibility of T. glabrata to muralysis disappeared completely within 2 h during the transition from exponential to stationary phase of growth, while in C. albicans and S. cerevisiae susceptibility diminished gradually during the stationary phase. It is postulated that such alterations in susceptibility are due to changes in the chemical composition of the wall concomitant with depletion of metabolites in the medium. Such changes could involve increases in the wall phosphomannan content or possibly a more extensive cross-linking of existing glucan and mannan polymers in the wall.Loss of walls, changes in volume, and the general appearance of these yeasts during treatment were followed by dark-field and phase-contrast microscopy, as well as by thin-section electron micrography.
Increase in glyoxylate shunt enzymes during cellular morphogenesis in Myxococcus xanthus
Authors: Bland J. , Yeh Wu-Kuang , White D. , Hendricks A.
Published: February 2010

Isocitrate lyase (EC. 4.1.3.1) and malate synthase (EC. 4.1.3.2) increase during microcyst formation in Myxococcus xanthus. The increase in activity is inhibited by chloramphenicol and actinomycin-D.
The Dome fermentor: a versatile unit suitable for batch, continuous, and synchronous cultivation of microorganisms or tissue cells
Authors: Dawson P. S. S. , Kurz W. G. W. , Anderson M. , York A. E.
Published: February 2010

An inexpensive but versatile and reliable fermentor of novel design is described which may be used for cultivating a wide range of microorganisms and tissue cells in batch, continuous (single and multistage), and phased (synchronous) culture. It can be used advantageously for growing material sensitive to the shearing effects of circulation pumps or impellers of other fermentors. The conditions of aeration are comparable with those observed in conventional fermentors.
Formation of 3,3′,3′,4,4′-tetrachloroazobenzene from 3,4-dichloroaniline in Ontario soils
Authors: Sprott G. D. , Corke C. T.
Published: February 2010

The formation of 3,3′,4,4′-tetrachloroazobenzene (TCAB) from 3,4-dichloroaniline (3,4-DCA) was studied using four Ontario soils. The disappearance of 3,4-DCA from Guelph loam was primarily due to chemical mechanisms under anaerobic and water-saturated conditions, while under aerobic and water-unsaturated conditions about 25% of the loss could be attributed to microbial activity. Only a small percentage of the disappearance of measurable 3,4-DCA was associated with TCAB formation. TCAB was formed in varying amounts in the limited number of soils examined. None was formed in a Peel clay. The optimum soil temperature for formation of TCAB was 25 °C, and the optimum concentration of 3,4-DCA required was found to be 500 μg/g of soil. Maximum conversion of 3,4-DCA to TCAB was 4.8% at optimal conditions. In soil shown to have an Eh of about −300 mV, TCAB formation was strikingly reduced. TCAB formed in low concentrations in Guelph loam disappeared with continued incubation, and evidence is presented for non-biological degradation of this condensed molecule.
Polyacrylamide gel electrophoresis of exoenzymes produced by Pseudomonas fluorescens strain W
Authors: Winters Harvey , Corpe W. A.
Published: February 2010

Culture filtrates from strain W of Pseudomonas fluorescens that cause lysis of gram-negative bacterial cell envelopes were examined for specific hydrolases. The enzymes were concentrated by ammonium sulfate fractionation and by column fractionation on Sephadex G-100. Attempts to separate the individual hydrolases quantitatively by elution from DEAE-cellulose failed because of the formation of aggregates. Resolution of the individual hydrolases was accomplished by disc gel electrophoresis using polyacrylamide (7.5%) gels buffered at pH 8.9 with Tris-glycine. The enzyme mixture was separated into 13 distinct protein bands which were stained with Coomassie blue. The individual hydrolases were detected either directly on the gels or by assay after elution from gel segments and included four proteinases, three phosphatases, two β-glucosidases, one ribonuclease, one lipase, one esterase, and one catalase. These methods provide a rapid, sensitive technique for the detection of many individual hydrolases in a complex mixture.
The effect of reticulocytosis on Plasmodium vinckei infection in white mice. Action of phenylhydrazine and of repeated bleedings
Authors: Viens P. , Chevalier J. L. , Sonea S. , Yoeli M.
Published: February 2010

Phenylhydrazine-HCl in a single dose of 0.06 mg/g protects mice against a virulent strain of P. vinckei. This drug does not seem to have any immediate effect on the parasite and would act mainly by inducing reticulocytosis. Bleeding-induced reticulocytosis affords the same degree of protection as with haemolytic drugs, thus confirming the role of reticulocytosis.Quantitative data show that the parasite cannot achieve full development in an immature red cell. Surviving mice display a strong immunologic protection against subsequent P. vinckei infection.
Observations on the polyhedra and virions of the cabbage looper nuclear polyhedrosis virus, with special reference to the viral membranes
Authors: Drake E. L. , Cameron M. L.
Published: February 2010

Polyhedra of the cabbage looper nuclear polyhedrosis virus dried down on a grid are essentially iso-diametric with a mean diameter of 1.05 microns. Profiles of polyhedra in infected tissue sections have a maximum diameter of 1.5 microns. Dimensions of the virions vary according to the location of the virions, from a minimum of 305 millimicrons in length and 51 millimicrons in width when within polyhedra to a maximum of 358 millimicrons in length and 87 millimicrons in width when free in infected fat body nuclei. Both viral membranes present a helical substructure when analyzed photographically. The helical pattern of the outer membrane has a pitch of 28.3° and an interval between successive turns of 56 Angstroms; the pattern on the inner membrane has a pitch of 45.3° and an interval of 107 Angstroms.
The ultrastructure of Crithidia fasciculata. A freeze-etching study
Authors: Easterbrook K. B.
Published: February 2010

The morphology and structure of C. fasciculata has been studied by scanning microscopy and after freeze-etch preparation. The results thus obtained have been compared with those obtained after routine processing of organisms by chemical fixation and plastic embedment. Essentially no differences in structure were observed by the different methods but freeze-etching revealed additionally details of both the inner and outer membrane surfaces of the body and flagellum of the organism, deoxyribonucleic acid (DNA) of the kinetoplast, and the micro tubular system.
Ultrastructural changes in tissues of larval Elateridae (Coleoptera) infected with the fungus Metarrhizium anisopliae
Authors: Zacharuk R. Y.
Published: February 2010

The ultrastructural changes that occur in the cells of the hypodermis, fat body, Malpighian tubule, midgut, ventral abdominal ganglion, and muscle during mycoses in three species of elaterid larvae infected with Metarrhizium anisopliae are described. The fungus penetrated all the above tissues before host death in most of the larvae examined. In some infected larvae, however, particularly in the smaller individuals or species, only the hypodermal and fat tissues were penetrated before death. Changes in fine structure appear in all the tissues soon after the fungus enters the hemocoel, even when no fungal growths are present near the host cells. In general, there is initially an increase in the number of lysosomes and of endoplasmic reticulum and ribosomes, followed by a vesiculation of the endoplasmic reticulum and of the cristae of the mitochondria and a progressive vacuolation of the cytoplasm. In some tissues the mitochondria increase in number before vesiculation. Glycogen granules and lipid and oil inclusions disappear rapidly during mycosis. Clear, membrane-limited vacuoles become particularly abundant in the Malpighian tubules and the midgut, suggesting increased secretion of fluids into their lumens. At or soon after death, the lysosomes disappear and all the membranous structures of the cells are disrupted, and laminated or whorled bodies of thickened membranes become numerous. Disintegration of all tissues, including muscle and nerve, was extensive in some larvae that were still capable of some sluggish movement before fixation for the study. It is suggested that the fungus incites lysosome production by the host tissues along with the other initial changes observed, and that final disintegration of the host tissues is by a process of autohistolysis.
Differentiation of human mycoplasma using gas chromatography
Authors: Meyer Donna M. , Blazevic Donna J.
Published: February 2010

Four strains of Mycoplasma pneumoniae, seven strains of M. salivariam, two strains of M. orale, two strains of M. hominis, and one strain of M. fermentons were grown for 6 days in PPLO broth containing horse serum and yeast extract. The cultures were harvested by centrifugation, and the resulting sediments were digested with tetramethylammonium hydroxide. Ethyl alcohol suspensions of the digestion products were analyzed by gas chromatography. All the species except M. pneumoniae produced three distinctive chromatographic peaks. Two of these peaks were reproducible, and M. salivarium, M. orale, M. hominis, and M. fermentons could be differentiated on the basis of the peak height ratios.
Enhancement of algal growth in Cyanophyta–bacteria systems by carbonaceous compounds
Authors: Lange Willy
Published: February 2010

Planktonic blue-green algae are always associated with bacteria. This association leads to enhanced or abundant algal growth when atmospheric carbon dioxide becomes a limiting factor and bacteria-assimilable carbonaceous matter is added. The study was carried out with 12 bacteria-associated blue-green species and 22 aliphatic, bacteria-assimilable carbon compounds. A normal, phosphate-rich Zehnder–Gorham culture medium (No. 11) was used. The bacterial assimilation of the aliphatic matter apparently leads to the production of CO2, which accelerates algal photosynthesis. The observed growth effects are not specific for a particular algal species. They appear to be specific mainly for the bacteria which happen to be associated with the algal cells. Similar growth enhancement was observed when the atmosphere was enriched with 0.5% CO2. With this augmented supply of atmospheric CO2, however, the enhancing effect of organic matter disappeared. The presence of the organic additives also appears to delay bacterial assimilation of organic chelating agents which have been added to keep iron and essential trace elements accessible to the algae in an alkaline medium. Axenic cultures of those algal species which cannot use added carbonaceous compounds did not show any effect of the additive. The results suggest that bacteria-assimilable carbon compounds may be one of the factors leading to algal bloom in lakes and ponds, especially when growth is not limited by the supply of phosphorus or other inorganic elements.
Fluctuating virus and enzyme levels in plasma of mice infected with the Friend leukemia virus
Authors: Buscher T. J. , Frantsi C. , Gregory K. F.
Published: February 2010

The levels of several plasma enzymes, plasma virus titers, and the percentages of blood cells which were reticulocytes were determined at intervals following the infection of white Swiss mice with the Friend leukemia virus (FLV). Lactate dehydrogenase, isocitrate dehydrogenase, aldolase, and glutamic-oxalacetic transaminase showed large simultaneous increases, alternating with decreases to normal levels, which coincided with fluctuations in virus titers (spleen focus assay). The time of the initial peaks depended on the inoculum size and was the same within replicate mice but subsequent peaks were not synchronous in different mice. The number of reticulocytes usually showed a similar fluctuation which lagged behind the enzyme and virus titer changes. Simultaneous infection with FLV and the lactate dehydrogenase virus resulted in larger but more erratic plasma enzyme changes. Attempts to associate interferon production with the fluctuating virus titers were unsuccessful.