bluuebunny/crossref_metadata_2025 huggingface dataset:
Scanning electron microscopy of L-phase streptococci. II. Growth in broth and upon Millipore filters
Authors: Bibel David J. , Lawson John W.
Published: February 2010

The growth of L-phase streptococci in broth and upon Millipore membrane filters was studied by light and scanning-beam electron microscopy. Osmotic sensitivity, shape, size, and surface features of L-phase bodies, ratios of large bodies to granules, and number of units in clusters varied with the phase of growth in broth. During the lag phase of growth the L-phase elements seemed to possess a weakened membrane as suggested by their increased susceptibility to osmotic lysis and their flattened shape. Irregular protuberances, which may be associated with formation of elementary corpuscles or degeneration of membrane, were found on large bodies in stationary phase. Replication in broth appeared to occur by single budding of large bodies or binary fission of granules measuring 0.7 μm or more in diameter. L-Phase colonies of group D streptococci, strains F24 and Z30, and group A streptococci, strains ADA, AED, and GL8, were differentiated by morphology when grown on Millipore membrane filters pressed upon uniform agar medium. Both group and strain variation were observed.
Tryptophan stimulation of growth and sporulation of Rhizopus arrhizus Fischer
Authors: Gunasekaran M. , Weber D. J.
Published: February 2010

Individual amino acids (0.002 M) when added to Fothergill's medium stimulated the growth of Rhizopus arrhizus. Maximum growth was obtained with shikimic acid and the next highest growth with tryptophan. Sporulation was stimulated in the dark by the addition of tryptophan or methionine. Rhizopus arrhizus grown in tryptophan medium produced indoleacetic acid (IAA). The addition of IAA to Fothergill's medium did not increase the amount of growth and did not stimulate sporulation in the dark.
Enrichment and selective isolation of Caryophanon latum
Authors: Smith D. L. , Trentini W. C.
Published: February 2010

Nineteen isolates of Caryophanon latum were tested for sensitivity to several antibiotics. All isolates were found to be resistant to high concentrations of streptomycin sulfate while maintaining natural trichome morphology. Based on this finding an isolation procedure using differential low-speed centrifugation, filtration, and streptomycin resistance was devised which resulted in the selective isolation of C. latum from cow dung enrichments. This procedure results in C. latum accounting for about 70% of the colonies found after dilution and spreading onto cow dung – streptomycin agar.
The immunology of streptomycetes in terms of the cytoplasmic antigens
Authors: Kwapinski J. B. G.
Published: February 2010

Cytoplasms of 61 Streptomycetes, 236 other Actinomycetales, and 12 cytoplasms of C. albicans, Diplococcus, Streptococcus, and Staphylococcus were examined against anticytoplasm sera by an immunodiffusion method. The streptomycetes were found to contain between two and six major antigenic components and many strains were mutually related. Nine cytoplasmic serogroups were differentiated. The Streptomyces cytoplasms proved to be immunologically related to A. naeslundii; to a number of Nocardiae, notably N. pelletieri and N. madurae; and to a very few saprophytic and scotochromogenic mycobacteria, as well as to Candida, Diplococcus, and Streptococcus. It is suggested that Streptomyces has represented a natural biological linkage between the Actinomycetales and lower fungi.
Pyruvate kinase of Neurospora crassa: effect of various ligands on the rate of inactivation by protein denaturants
Authors: Kapoor M. , Tronsgaard T. M.
Published: February 2010

The effect of substrates, products, and related ligands of pyruvate kinase on the rate of inactivation of the enzyme by urea, guanidine hydrochloride, SDS, and PHMB, is reported. PEP, ADP, ATP, and Mg2+ protected the enzyme from PHMB inactivation; complete protection was afforded by relatively low concentration of these ligands. The enzyme was also protected strongly from urea inactivation by PEP and Mg2+ but ATP and ADP accelerated the rate of inactivation in a dramatic manner. While PEP and Mg2+ proved to be mild protectants against SDS-induced inactivation, ADP and ATP exhibited a dual effect, showing protection at low concentrations and enhancement of inactivation at higher concentrations. FDP appeared to be the most potent protectant against SDS. With respect to GuHCl-promoted inactivation of pyruvate kinase, FDP caused a very pronounced increase of the inactivation rate, whereas PEP was a weak protectant and ADP elicited a slight acceleration of inactivation. There was no evidence of dissociation of the enzyme during inactivation experiments.
Comparative effect of temperature on the induced synthesis of hydrogenase and enzymes of the benzoate oxidation system in psychrophilic and mesophilic bacteria
Authors: Quist R. G. , Stokes J. L.
Published: February 2010

Cell suspensions of the psychrophilic bacterium, strain 82 produced the maximum amount of hydrogenase at 15C. No induction occurred at 25C and a limited amount of enzyme was formed at 0C. In comparison, mesophilic Escherichia coli and Aerobacter aerogenes produced maximum amounts of enzyme at 35C and 30C, respectively. No induction occurred at 10C.Psychrophilic Pseudomonas fluorescens produced maximum amounts of enzyme involved in benzoate oxidation at 25C and a large quantity of enzyme was produced at 5C. Induction did not occur at 35C or at 0C. In comparison, mesophilic Pseudomonas aeruginosa produced the largest amount of enzyme at 30C; induction did not occur at 45C or at 10C. Induction was most rapid for the psychrophile at 25C as contrasted to 35C for the mesophile.The data clearly show that the temperature range for induction of the above enzymes and for maximum enzyme formation is considerably lower in the psychrophiles than in the mesophiles.
Occurrence of choline in Lactobacillus plantarum
Authors: Ikawa Miyoshi , Chakravarti Ashima , Taylor Richard F.
Published: February 2010

When Lactobacillus plantarum 8014 was grown on a Trypticase Soy Broth (TSB) type of medium, choline accumulated within the cells, whereas when the same organism was grown on a semisynthetic medium, no choline accumulation was observed. Only the addition of choline O-sulfate resulted in the accumulation of choline in cells grown on semisynthetic medium to the extent seen in cells grown on TSB medium. The choline of TSB-grown cells is shown to be non-lipoidal and to occur in the cells as free choline, choline O-sulfate, and choline O-phosphate. No choline was detected in the cell wall of the choline-containing cells.
Studies on conidial germination and appressorium formation by Colletotrichum trifolii Bain & Essary
Authors: Miehle B. R. , Lukezic F. L.
Published: February 2010

Conidial germination of Colletotrichum trifolii was affected by concentrations of Tween 20 (polyoxyethylene sorbitan monolaurate). The highest rate of germination and appressorium formation was obtained in 0.083% Tween 20.Appressorium formation was more sensitive to temperature than was germination. The percentage of germinated spores which formed an appressorium was reduced when the spore suspensions were incubated for 24 h at incubation temperatures above 27 °C. Appressorium formation also was reduced when conidia were exposed, in culture or in suspension, to 35 °C for short periods. Similarly, germination was reduced with heat exposure, but at longer exposures than those necessary to reduce appressorium formation. Spores in suspension responded to a shorter heat exposure (4 h) than spores in culture.The reduced atmospheric CO2 level did not affect the amount of germination or appressorium formation. However, cell walls of appressoria produced in an atmosphere low in CO2 were thin-walled and without the brown pigment characteristic of normal appressoria.Protein synthesis inhibitors (cycloheximide and p-fluorophenylalanine) blocked both germination and appressorium formation. Nucleic acid synthesis inhibitors were either partially effective or ineffective and their mode of action in C. trifolii is unknown.
Isoprene-containing metabolites of Aspergillus amstelodami
Authors: Allen Jr. Charles M.
Published: February 2010

The chromatographic separation of several metabolites of the fungus A. amstelodami is described. The production of two of these metabolites, flavoglaucin and echinulin, is shown to increase with increasing sucrose concentration in the growth medium and increasing time of growth. Furthermore, the metabolites are shown to be associated with formation of perithecia. By the use of in vivo double-labeling experiments, two new metabolites containing 1 mole each of tryptophan and alanine have also been demonstrated.The enzyme isopentenyl pyrophosphate isomerase has been demonstrated in cell-free preparations and partially purified. Time-dependent studies of the isomerase activity shows that there is a peak of enzyme activity 7 days after inoculation of cultures. This activity peak precedes the maximum elaboration of metabolites by 2–3 days.
Capsular antigens of Staphylococcus aureus. I. Further purification of the capsular antigen of a major capsular type of Staphylococcus aureus
Authors: Maverakis N. H. , Wiley B. B.
Published: February 2010

Partially purified staphylococcal capsular material (PPCM) prepared from a major capsular type was further purified by exclusion chromatography. Sephadex G-100, G-200, and Sepharose 6B were used in the study of the staphylococcal capsular material. The starting material placed on the column consisted of at least three components, whereas one of the fractions obtained after chromatography on Sepharose 6B exhibited a single precipitin arc in immunoelectrophoresis. The purified component absorbed antibodies from a homologous anticapsular serum completely abolishing the specific capsular reaction.
Localization of canine adenovirus capsid antigens in a MDCK cell line by immunoferritin and immunofluorescent techniques
Authors: Shahrabadi M. S. , Yamamoto T.
Published: February 2010

The appearance and development of infectious canine laryngotracheitis adenovirus capsid antigens and their relationship to the viral induced inclusions in a canine cell line was determined using the method of staining thin sections with ferritin-labeled antibody and compared with the fluorescent-staining technique.The adenovirus fiber was the first structural antigen to appear and was detected at 9–10 h after infection in the early initial and ring-form nuclear inclusions by both the immunoferritin and immunofluorescent methods.The hexon and penton base antigens were only detectable about 2 h after the appearance of the fiber antigen. These antigens when visualized with the fluorescent technique appeared to be diffusely scattered throughout the nucleus but the ferritin technique showed that they were associated with the newly formed virus particles.The later appearing light-staining nuclear inclusions examined by ferritin staining were found to contain hexon, penton base, and fiber antigens. The dark-staining inclusion which also appears later in infection was found to contain only the hexon antigen.
Perméation du glycérol et sporulation chez Bacillus subtilis
Authors: Saheb S. A.
Published: February 2010

Glycerol permeation was studied in B. subtilis 168 trp− gl+ and its two mutants gl−1 and gl−2. The mutant gl−1 has all the enzymes required for the degradation of endocellular glycerol. The mutant gl−2 is impaired in the enzyme glycerol kinase. In the presence of increasing concentrations of glycerol-14C, incorporation of radioactivity by the wild strain obeys Michaelis law while it is linear in the case of the mutant gl−1. Thus the mutant gl−1 is cryptic towards glycerol. No evidence was found as to the formation of an intracellular pool of glycerol in any of the three strains (gl+, gl−1, gl−2) studied. This result suggests that permeation of glycerol in B. subtilis is probably facilitated by diffusion. Sporulation of the mutant gl−1 in presence of glycerol is explained by a mutation affecting the permeation system. Thus glycerol enters in the mutant cells by simple diffusion. As a consequence, the metabolism is greatly reduced and the sporulation mechanism is triggered.
Etude de deux mutants du métabolisme du glycérol chez Bacillus subtilis
Authors: Saheb S. A.
Published: February 2010

As in different microbial species, two pathways for the degradation of glycerol are found in B. subtilis 168. Each pathway includes two enzymes which can catalyze the formation of dihydroxyacetone phosphate from glycerol in vitro. The first pathway includes a glycerol dehydrogenase (gl-D) and a dihydroxyacetone kinase (dha-K). The second pathway includes a glycerol kinase (gl-K) and an α-glycerophosphate dehydrogenase (glp-D). Enzymes of both pathways are repressed in the presence of glucose. Only the enzymes of the second pathway are inducible. The inducer is probably glycerophosphate, utilization of which as a carbon source by B. subtilis is demonstrated. Degradation of glycerol in B. subtilis proceeds through the second pathway. This was demonstrated by the isolation of a mutant (gl−2) impaired in glycerol kinase, and which cannot use glycerol as a carbon source. Another mutant (gl−1)was isolated, which cannot use glycerol as a carbon source. When comparing the activity of the four enzymes, particularly gl-K, no significant differences were observed between the wild strain and the mutant gl−1. This leads one to consider the existence of a glycerol permeation system in B. subtilis. A mutation affecting this system would explain the behavior of the mutant gl−1.
Preliminary characterization of a chlamydial agent isolated from embryonated snow goose eggs in northern Canada
Authors: Wilt Paul C. , Kordová Nonna , Wilt John C.
Published: February 2010

Chlamydiae-like, streptomycin-resistant parasites have been isolated from a high percentage of embryonated snow goose eggs collected at various stages of incubation; the agents stained specifically by immunofluorescence with antiserum against psittacosis and multiplied intensively in the yolk sacs of chicken embryos and induced in mice the production of antibodies that reacted in complement-fixing (CF) tests with a psittacosis group antigen. The isolates showed a high infectivity, but a low pathogenicity for chick embryos and mice. High doses of the isolate produced no cytopathic effect (CPE) in cultured mouse peritoneal macrophages and L cells. Release of lysosomal acid phosphatase did not occur in the inoculated macrophages throughout the time of observation.
Nuclear movement in Erysiphe graminis hordei
Authors: McKeen W. E.
Published: February 2010

The nucleus in the powdery mildew cell may move before, during, and after division. Sometimes the nucleus was surrounded by several membranes and sometimes microtubules which originated in the spindle plaque and fanned out into the cytoplasm. Long straight or undulating strands, about 0.5–1 μ, in width and many microns in length composed of microtubules or laminated membranes, were observed in Erysiphe graminis cells in which nuclei move, but were not observed in conidia, where nuclei remain stationary. The end of the strand, sometimes, was attached to the nuclear membranes, and other times extended past the nucleus. It is postulated that the strands, astral microtubules, and spindle plaques are associated with controlled nuclear movement which is independent of cytoplasmic streaming.
Utilization of amino acids by Halobacterium cutirubrum in chemically defined medium
Authors: Ducharme Louise , Matheson A. T. , Yaguchi M. , Visentin L. P.
Published: February 2010

As part of a project involving the labeling of the ribosomal proteins of the extreme halophile Halobacterium cutirubrum with 14C-lysine, the chemically defined medium of Gochnauer and Kushner (2) was modified to allow maximal incorporation of 14C-lysine. The utilization of the other amino acids present in this medium was also measured. Of special interest was the rapid and complete disappearance of arginine from the medium before the beginning of log-phase growth.
The branchpoint of pyocyanine biosynthesis
Authors: Longley R. P. , Halliwell J. E. , Campbell J. J. R. , Ingledew W. M.
Published: February 2010

Mutant strains of Pseudomonas aeruginosa, blocked in the pathway of aromatic amino acid biosynthesis, were isolated to determine the branchpoint of pyocyanine biosynthesis. Studies of the enzyme complement of these mutants and determination of pyocyanine production indicated that chorismic acid is an intermediate in the pathway and is the branchpoint compound.
Relationships between host origin of staphylococcal strains and their virulence for mice
Authors: Chesbro William , Taylor Nancy , Smith Melvin
Published: February 2010

Staphylococcus aureus strains from human and bovine infections were compared for mouse virulence by intraperitoneal injection and for the expression of a variety of physiological characteristics. Secretion of fibrinolysin, ability to reduce thionin, and production of delta hemolysin correlated with host origin but not mouse virulence. Production of clumping factor, pigmentation, and crystal-violet agar reaction varied from strain to strain, but correlated with neither virulence nor host origin. Beta-hemolysin production correlated with virulence in a manner dependent on host origin: human-derived, beta-positive strains were all mouse virulent; bovine-derived, beta-negative strains were all mouse avirulent. Bovine-derived, mouse-virulent strains exhibited a smaller mean cluster size and either a more rapid growth rate, or shorter lag period, than bovine-derived, mouse-avirulent strains. Bovine-derived strains were also significantly more virulent for mice than were human-derived strains. The virulence mechanisms of a given S. aureus strain for mice are thus in part related to its host origin. Protease-negative strains were mouse avirulent whatever their origin, pointing toward a general role in staphylococcal virulence for the protease, since it was previously shown that negative strains are also of low virulence for cattle.
An agar medium for the isolation and macroscopic recognition of Phytophthora spp. from soil on dilution plates
Authors: Sneh B.
Published: February 2010

An agar medium containing corn oil and antimicrobial compounds was developed on which Phytophthora colonies can be isolated and recognized macroscopically after 4 days of incubation. The presence of Pythium ultimum Trow, did not interfere with the recognition of P. cactorum colonies.The medium is suitable also for the isolation from soil of Phytophthora nicotianae var. parasitica, P. cinnamomi, and P. drechsleri, but less satisfactory for the enumeration of P. cryptogea, P. cambivora, and P. megasperma var. sojae.
The effect of osmotic shocking upon Bacillus subtilis transformation
Authors: Pierson Duane L. , Weppner William A. , Leach Franklin R.
Published: February 2010

Osmotic shocking of competent Bacillus subtilis reduced transformability by 80–90% through depressing the uptake of radioactive DNA. The supernatant solution from competent cultures restored both transformation and DNA uptake. A factor, which was inactivated by proteolytic enzymes and which was released into the supernatant solution concomitant with the development of maximum competence, was responsible for restoration of transformability. This factor was both heat and pH labile and was produced only by competent strains. While the shock fluid did not restore transformability to shocked ceils, it increased competence 20-fold in a low-transforming strain. The supernatant solution from competent cultures also increased transformability of the low-competence strain. Thus it appears that at least two factors are involved in competence restoration.
Phenotypic properties of a large-cell, radiation-resistant strain of Escherichia coli
Authors: Kvetkas Marilyn J. , Krisch Robert E. , Zelle Max R.
Published: February 2010

Mean cell volumes, total amount of deoxyribonucleic acid (DNA), number of nuclear bodies, and X-ray responses were determined for exponential cultures of Escherichia coli P6, a large-cell radiation-resistant mutant strain, and for E. coli 82/r, the parent strain of P6, growing in three different media at varying growth rates. Combined results comparing cultures in the same growth medium indicated that exponentially growing P6 cells are 2,5 ± 0.2 times larger, contain 3.6 ± 0.3 times more DNA, and 1.8 ± 0.1 times more nuclear bodies than comparable 82/r cells. Individual P6 nuclear bodies contained 2.01 + 0.13 times as much DNA as 82/r nuclear bodies in comparable cultures, suggesting that each P6 nuclear body may contain two complete 82/r genomes. All P6 cultures gave sigmoidal X-ray survival curves with extrapolation numbers averaging 2.0 and with limiting slopes smaller in absolute value than the slopes of the exponential survival curves obtained for 82/r cultures. P6 cells appeared to be no more efficient than 82/r cells in enzymatic dark repair of X-ray or ultraviolet damage, suggesting that the greater X-ray resistance of P6 cells may be associated with the doubled DNA content of each P6 nuclear body.
Characterization of Mycoplasmas isolated from the bush baby (Galago crassicaudatus)
Authors: Cole B. C. , Graham C. E. , Golightly-Rowland L. , Ward J. R.
Published: February 2010

Mycoplasma salivarium was isolated from the oropharynx of four out of seven Galagos and M. arthritidis was obtained from the nasopharynx of three out of six Galagos. Biochemical and serological studies failed to differentiate the M. salivarium isolates from those of human origin. The M. arthritidis isolates appeared identical with strains occurring in rats and they were found to be highly arthritogenic when injected i.v. into young rats.Five out of seven animals harbored an unidentified glucose-fermenting Mycoplasma species which appeared to be biochemically and serologically related to, but distinct from, M. felis of cat origin. This preliminary investigation indicated that the glucose-fermenting Galago strains represented a new species of the Mycoplasmataceae.
L'ontogénie sporale et l'ultrastructure de la paroi chez Paecilomyces berlinensis
Authors: Oláh György-Miklós
Published: February 2010

The sporal ontogeny and ultrastructure of the wall and of the site of mycelial anastomose of Paecilomyces berlinensis Oláh and Ackermann have been the object of our recent investigations. According to the results obtained, this fungus possesses a sporogenesis of the subendogene phialospores type. One can distinguish many zones of polysaccharide nature forming the conidial wall or mycelium. By the replica technique the external structure of the phialide and of the conidia is shown in electron micrographs.
Differentiation between Pseudomonas testosteroni and P. acidovorans by gas chromatography
Authors: Brooks John B. , Weaver Robert E. , Tatum Harvey W. , Billingsley Sue A.
Published: February 2010

Pseudomonas acidovorans can be distinguished from P. testosteroni by gas chromatography on the basis of acids detected after 20 h growth on heart infusion agar plates. The data obtained support the findings of other workers that P. acidovorans and P. testosteroni are two different species and indicate that gas chromatography may be used effectively to distinguish other members of the genus.
Hydrolytic enzymes of some periphytic marine bacteria
Authors: Corpe William A. , Winters Harvey
Published: February 2010

Several periphytic marine bacterial cultures were examined for their content of hydrolytic enzymes. Quantitative assays were done for extracellular and intracellular proteinase, phosphatase, esterase, β-glucosidase, and four polysaccharide hydrolase activities. While some of the enzymes were released extracellularly by growing cells, the greatest amounts of proteinase, esterase, phosphatase, and β-glucosidase were located in the cells and released by mechanical breakage or by cell autolysis. Substantial amounts of proteinase were found in washed cell envelopes of the bacteria. All of the bacteria showed some enzymatic activity against one or more of the algal and microbial acid polysaccharides tested. Enzymes active against these polyanions were found either extracellularly or in cell extracts, depending on the culture concerned. Partial lysis of cell envelopes from two of the periphytes was produced by extracellular or intracellular enzyme mixtures. The ecological importance of bacterial hydrolases and the possible relationship of periphytic bacteria to grazing and detritus feeding invertebrates is discussed.
Lysogenic conversion of the lipase in Staphylococcus pyogenes group III strains
Authors: Duval-Iflah Yvonne
Published: February 2010

Staphylococcus pyogenes PS54, the propagating strain of the group III staphylococcal typing phage 54, manifests no lipase activity on egg yolk medium. This strain was found to harbor at least two prophages. One of these, designated as L54a, was demonstrated to be capable of suppressing lipase production by lysogenic conversion of strains of Staphylococcus pyogenes previously manifesting lipase activity.Suspensions of typing phage 54 were also found to contain substrains of phage having the same conversion property, with respect to lipase activity, as L54a. These converting phages differed from L54a with respect to their ultrastructure and their lytic spectra. They may have arisen by means of recombination between non-converting typing phage 54 and the prophage L54a carried in the propagating strain of Staphylococcus.
Natural and induced bactericidal activities in the hemolymph of the lobster, Homarus americanus: products of hemocyte–plasma interaction
Authors: Stewart James E. , Zwicker B. M.
Published: February 2010

The salient features of this study of the enhancement of bactericidal activity in the hemolymph of the American lobster were as follows: (a) increase in response to a number of non-pathogens isolated from the lobster's intestinal tract (several pseudomonads, an Achromobacter and Sarcina lutea), (b) one isolate identified as Pseudomonas perolens was used for the bulk of the studies, (c) apparent bactericidal activity of the hemolymph increased severalfold with reduction of the pH of the assay system from the physiological value of 7.6 to a value of 6.0, (d) the extent of the enhancement in vivo was roughly proportional to the concentration of the vaccine, (e) the bactericidal activity's enhancement in vivo was temperature dependent, (f) heat-stability trials indicated the probable presence of more than one bactericidin, (g) the bactericidal principle(s) exists in vivo in an inactive form until activated by material contained within the hemocytes, (h) no protection against Gaffkya homari was conferred on the lobster by prior treatment with vaccines prepared from P. perolens, G. homari, or S. lutea.
An inexpensive versatile incubator for soil biological research
Authors: Dyck F. B. , Campbell C. A. , Weinberger J. F. , Biederbeck V. O.
Published: February 2010

A household freezer was converted to an inexpensive incubator by incorporating a heating system and a controller unit. The temperature was automatically varied sinusoidally over a 24-h cycle or maintained at a constant level. Cost, excluding labor, was $400.The specifications are maximum and minimum temperatures, 38 and −21 °C; maximum and minimum ranges of the sinusoidal temperature, 22 and 4 °C; accuracy, ± 0.5 °C.
Halogenated compounds for the sensitive detection of clostridia by gas chromatography
Authors: Mitruka Brij M. , Alexander Martin
Published: February 2010

Metabolites formed by the equivalent of 230 to 3000 cells of several Clostridium species were detected by use of a gas chromatograph fitted with an electron capture detector. A variety of organic acids, alcohols, and ketones were produced by growing cultures of the 10 species tested. Compounds excreted by 300 to 3000 cells of 12 strains of Clostridium perfringens were detected, and both common and dissimilar metabolites were formed by these strains. The sensitivity for detecting six Clostridium species increased up to several thousandfold when chlorophenoxyacetates were added to the medium, the increase being most marked with 2,4-di- and 2,4,5-trichlorophenoxyacetates. The results show that cometabolism is useful in increasing the sensitivity and speed of detection of Clostridium species.
Interactions entre Staphylococcus aureus et Pseudomonas aeruginosa dans des cultures in vitro et au cours d'infections expérimentales
Authors: Repentigny J. de , Mathieu L. G. , Gadbois T.
Published: February 2010

Staphylococcus aureus and Pseudomonas aeruginosa are often found in succession or in association in infections. To study experimentally their interactions, we have used systems of growth or survival of mixed cultures of both species in vitro in a semisynthetic medium and in vivo in the peritoneal cavity of mice. Conditions for maximum growth in vitro of both species in mixed cultures are about similar to those in pure culture when the pH is maintained between 6.0 and 7.3. The inhibition of S. aureus growth by some antimetabolites or antibiotics, e.g., 5-methyltryptophan and D-cycloserine, is antagonized in mixed cultures. Staphylococcus coagulase, DNase, and alpha toxin were present either in mixed cultures or after mixing pure culture supernatants of both species, but P. aeruginosa slime was not observed in these conditions. In vivo, the survival of S. aureus seemed greater in mixed infections with P. aeruginosa than in those with S. aureus alone. In our systems, S. aureus may have benefited from the presence of P. aeruginosa whereas the reverse was not observed. These observations on interbacterial ecology could help to explain the importance and the behavior of some species at the initiation of pyogenic infections, either their interactions or their selection.
Stimulation of β-(l → 6)-glucanase production by oxidized pustulan
Authors: Brown Robert G.
Published: February 2010

A strain of Penicillium lilacinum, isolated from soil, produced pustulanase, β-(1 → 3)-glucanase, (EC. 3.2.1.6) and cellulase (EC.3.2.1.4) when cultivated on a medium containing pustulan as the sole source of carbon. If pustulan was replaced by ketopustulan, the production of pustulanase was stimulated about 10-fold although the amount of stimulation was dependent on the degree of oxidation of pustulan. β-(1 → 3)-Glucanase production was stimulated slightly by ketopustulan; however, the degree of oxidation did not affect significantly the yield of this enzyme. Cellulase production was either unaffected by the oxidized polymer, or at higher degrees of oxidation, decreased. Tween 80 stimulated the production of the three enzymes in media containing ketopustulan with a low degree of oxidation but was inhibitory to pustulanase and cellulase production in media containing ketopustulan with a high degree of oxidation. A combination of gel filtration and isoelectric focusing revealed that each enzyme activity was attributable to at least two proteins.
Bacteriolytic and bactericidal activity of maternal and cord sera. Relationship to complement, lysozyme, transferrin, and immunoglobulin levels
Authors: Pruzanski W. , Leers W.-D. , Wardlaw A. C.
Published: February 2010

Bacteriolytic activity and its relationship to the level of immunoglobulins, complement, lysozyme, and transferrin was measured in 20 pairs and bactericidal activity in 6 pairs of maternal and cord serum. Escherichia coli Lilly, an organism easily lysed by normal human serum and four other Gram-negative bacteria were used.Cord sera invariably had lower bacteriolytic and bactericidal activity than their corresponding maternal sera. No statistically significant relationship between these activities and the level of immunoglobulins, complement, lysozyme, or transferrin was detected. A higher level of lysozyme was unable to compensate for the lower levels of other factors in the cord sera.
The phospholipids of Hansenula wingei, mating type 21
Authors: Wirth J. C. , Magliulo A. R.
Published: February 2010

The phospholipid fraction of the yeast H. wingei was studied by a combination of DEAE-cellulose column chromatography and thin-layer chromatography. Phosphatidyl choline, phosphatidyl serine, and phosphatidyl ethanolamine were identified. The absence of phosphoinositide was noted. An unknown acidic phospholipid accounts for less than 1% of the total phosphorus. A cerebroside or cerebroside-like compound was provisionally identified.
The fatty acid composition of conidia of Aspergillus niger V. Tiegh.
Authors: Gunasekaran M. , Hess W. M. , Weber D. J.
Published: February 2010

The lipids from conidia of Aspergillus niger were extracted and identified. The polar lipid content was higher (54.3%) than the neutral lipid fraction (45.7%). The major fatty acids present were C16:0, C18:0, C18:1, and C18:2. The amount of unsaturation in total fatty acids (62%) was higher than the unsaturation in the polar lipids (35%). Freeze-etched replicas of dormant conidia revealed the presence of lipid bodies.
Vibrio anguillarum as a cause of disease in winter flounder (Pseudopleuronectes americanus)
Authors: Levin M. A. , Wolke R. E. , Cabelli V. J.
Published: February 2010

Vibrio anguillarum was repeatedly isolated from skin and muscle lesions of the winter flounder, Pseudopleuronectes americanus. The dermal lesions, usually accompanied by fin necrosis, included petechiae and ecchymoses in their acute phase and frank ulceration in their more chronic manifestations. Anemia, as evidenced by lowered hematocrit values and increased renal hematopoiesis, was present. The disease was reproduced experimentally by the intradermal injection of as few as 640 V. anguillarum cells. The differential identification of the V. anguillarum isolates from aeromonads, plesiomonads, and other marine vibrios was described and discussed.
Pyrolysis–gas–liquid chromatography of some dermatophytes
Authors: Sekhon Awatar S. , Carmichael J. W.
Published: February 2010

Dermatophytes belonging to Nannizzia, Arthroderma, and Microsporum were examined by pyrolysis–gas–liquid chromatography. Replicate samples from the same colony, or samples from another colony of the same strain, yielded closely similar pyrograms, but the curves were not quite superimposable. Effects on the pyrolysis patterns of sample size, age of colony, and type of medium were investigated. Pyrograms of the plus and minus mating types of the species of Nannizzia and Arthroderma were similar to each other, but they did differ in some respects. The patterns of Microsporum audouini and M. canis differed considerably from each other. Quantitative analysis of the pyrochromatographic data, using several procedures, did not yield satisfactory results. It was found that variation between replicates was often as great as between species.
Adenovirus serum neutralization in micro-tissue cultures of rhesus monkey kidney cells
Authors: Furesz J. , Armstrong R. E. , Nagler F. P.
Published: February 2010

A micro-tissue culture assay using 2nd passage cells of primary rhesus monkey kidney for the neutralization of human adenovirus types is described. All 31 serotypes of adenovirus showed characteristic cytopathic changes 3 to 4 days after initiation of the test, and serum antibody titers were established on the 5th day. Virus infectivity and serum antibody titers were found to be greater than in the conventional tube test. Replicate neutralization test results demonstrated the good reproducibility of the micro assay. Heterotypic neutralization tests were carried out on six representative equine reference sera with all prototype viruses, and the specificity of the micro-assay system was established. Preliminary experiments indicated that 2nd passage Cercopithecus monkey kidney cells were also suitable for the micro-neutralization assay.
Gel electrophoresis of the cell envelope of a division mutant of Escherichia coli
Authors: Leighton P. M.
Published: February 2010

The cell envelopes of lon+ and lon− strains of Escherichia coli were compared by acrylamide gel electrophoresis. Lon− cells were found to have a decrease in a major component of the cell envelope.
Molecular species of interferon induced in mice by poly I:C and Mengo virus
Authors: Campbell J. B. , Grunberger T.
Published: February 2010

The molecular weights of the interferons appearing in the serum of mice injected intravenously with Mengo virus and with poly I:C are about 28 000 and 45 000 respectively. Since there is evidence that some forms of interferon are more potent than others, it is suggested that molecular-weight estimations might provide a convenient marker for more systematic studies of the efficacy of interferon preparations and inducing substances for clinical use.
Probable virus infections in four genera of green algae
Authors: Mattox Karl R. , Stewart Kenneth D. , Floyd Gary L.
Published: February 2010

Virus-like inclusions are described in four, filamentous ulotrichalean algae. The infected cultures, as well as some related, noninfected strains, are available from the Indiana University Culture Collection of Algae.
Erratum: Physiological and morphological effects of phenethyl alcohol upon a gram-negative marine pseudomonad
Authors: Thompson J. , DeVoe I. W.
Published: February 2010

not available
Rapid characterization of bacteria, with emphasis on Staphylococcus aureus
Authors: Fung Daniel Y. C. , Hartman Paul A.
Published: February 2010

Several miniaturized microbiological techniques were devised. These techniques were combined with multiple-inoculation methods for rapid characterization of Staphylococcus aureus strains isolated from turkey products. These procedures are applicable to a variety of other ecological investigations; they result in substantial savings of space, material, labor, and time.
Utilization of single L-amino acids as sole source of carbon and nitrogen by bacteria
Authors: Halvorson Harvest
Published: February 2010

The utilization of single L-amino acids as sole source of carbon and nitrogen by bacteria was studied and was found to be very common and widely distributed over many genera. Field soil contained large numbers of such bacteria; 7.7–79.2% of the colony count obtained on nutrient agar could be achieved by using a single amino acid as sole carbon and nitrogen source. Twenty taxonomically known bacteria which could use one or more amino acids were examined for the range of amino acids over which they could grow. Organisms which grew on one amino acid usually grew on several. Some ecological aspects of these findings are discussed.
Electron microscopy of leukocyte interaction with spores of Clostridium botulinum type A
Authors: Suzuki Jon B. , Grecz Nicholas
Published: February 2010

Phagocytosis of toxic spores of Clostridium botulinum type A by human polymorphonuclear leukocytes as revealed by electron microscopy involves engulfment on contact and rapid inclusion into phagocytic vacuoles, followed by a rather slow process of spore germination within the next 8 h. Once germinated, spores appear to be degraded intra-phagocytically almost instantaneously. No outgrowth of spores into vegetative cells was observed either within the leukocytes or outside. Pathogenicity of C. botulinum spores seems to depend on germination of spores within the phagocyte, degradation of germinated spores, and release of spore-bound toxin into body fluids; thus causing potentially fatal botulism poisoning.
Influences of environmental ionic strength, pH, and magnesium ion on bactericidal and lytic activities of β-lysin on Bacillus subtilis
Authors: Matheson A. , Kwong M. C. M. , Cheung R.
Published: February 2010

The technique of lyophilization has been used to prepare β-lysin that can be stored in aliquots at ordinary refrigeration temperatures. It has permitted the determinations of environmental ionic strength, pH, and magnesium ion concentration favoring bactericidal and lytic activities of this agent. Killing of cells as well as lysis of protoplasts of Bacillus subtilis were favored in environments not more than 0.2 nor less than 0.15 in ionic strength. Of the environmental pH tested (6.0, 7.0, and 7.5), lysis of cells and of protoplasts was most efficient at pH 7.5, whereas bactericidal action was relatively unaffected in this range. The effectiveness of bactericidal action and of lysis of protoplasts decreased as the amount of Mg2+ in the environment increased.
Effect of temperature on the cellular integrity of Bacillus psychrophilus
Authors: Alsobrook David , Larkin John M. , Sega Marsha W.
Published: February 2010

The release of intracellular materials from the psychrophile Bacillus psychrophilus at temperatures from 5 to 50C was studied as a means of indicating possible membrane damage. RNA, protein, carbohydrate, and inorganic phosphate, but not DNA was found to leak from the cells. The rate of leakage increased as the temperature was raised. It is shown that the amount of leakage at 40C in the length of time required for 90% death could be sustained at 25C with little or no death. Therefore, death of this psychrophile at supramaximal temperatures cannot be attributed to loss of membrane integrity with resultant loss of intracellular material. Electron micrographs of the cells demonstrated a trilaminar cell wall which becomes severely damaged during heating. The damage is irreversible at 40C and may contribute to heat-induced death.
Synchronized sporulation in Penicillium digitatum (Sacc.)
Authors: Zeidler G. , Margalith P.
Published: February 2010

Biochemical studies of the sporulation process in mycelial fungi require a thallus in which the conidiation (production of conidiophores and conidia) will take place in a synchronous manner.A method was worked out which permits an approximate evaluation of 5 degrees of the synchronous sporulation of Penicillium digitatum. A suitable nutritional regime for the cultivation of the fungus as mycelial felts was found to promote synchronous sporulation. A defined medium containing a vitamin mixture lacking p-amino benzoic acid (PABA) gave satisfactory growth and good synchronization. Other methods such as starvation of the mycelium, cold shock, etc. had little effect.
Changing patterns of 32P and 33P utilization in cells of Candida utilis during the cell cycle
Authors: Dawson P. S. S. , Glättli H.
Published: February 2010

Incorporation of 33P and 32P into different fractions of continuous phased (synchronized) cultures of Candida utilis was studied. Two different growth conditions (on C-limited and N-limited media) were used at a doubling time of 6 h. Incorporation of 33P and 32P into four fractions (lipid, cold-water ex-tractable, RNA and DNA) showed a variable, nonuniform, behavior during the cell cycle. Different patterns of incorporation between cells on the two media were observed.
Glycerol transport by Nocardia asteroides
Authors: Calmes Robert , Deal S. J.
Published: February 2010

Glycerol uptake in Nocardia asteroides exhibited biphasic kinetics suggesting that glycerol was translocated by at least two mechanisms. Uptake of glycerol at concentrations more than 80 μM followed the kinetics of free diffusion, whereas, glycerol concentrations less than 80 μM exhibited saturation kinetics typical of a specific transport system. This latter mechanism had the characteristics of constitutive facilitated diffusion or active transport; however, a definite energy relation was not established. After entry, glycerol was further catabolized by glycerokinase (EC. 2.7.1.30) whose specific activity increased 15-fold when cells were grown in a medium containing glycerol as the sole carbon source. The presence of glycerokinase did not enhance the rate of glycerol transport.
13C magnetic resonance and structural studies on the mannose-containing polysaccharides of some Pichia and Hansenula spp.
Authors: Gorin P. A. J. , Spencer J. F. T.
Published: February 2010

Mannose-containing polysaccharides were isolated from the cell walls of six Pichia and Hansenula species. These species were chosen from a group of 24 yeasts having polysaccharides with a similar spectrum, each giving proton magnetic resonance spectra with signals at τ4.24 and τ4.36. The polysaccharides were equated or distinguished by their 13C magnetic resonance (c.m.r.) spectra into three groups based on differing structures. The validity of this technique was borne out by conventional structural determinations. The polysaccharides were found to represent a new structural type, being predominantly linear and containing predominant (1 → 6)-linked α-D-mannopyranose units with (1 → 2)-linked units distributed regularly along the main chains.Some of the signals of the Hansenula capsulata mannan could be assigned to certain carbons indicating that the c.m.r. technique may have uses in structural investigations.
Dimension control in Micrococcus flavus
Authors: Paulton R. J. L.
Published: February 2010

The effect of nutrition on growth rate, cell size, and cell arrangement in Micrococcus flavus is described in relation to earlier studies of other bacteria. Progressive improvements in nutrition reduced the generation time from 15 to 1.7 h (at 25 °C), but septum formation occurred at about the same cell age in all growth cycles. In Gram-negative bacteria, the division site is also formed at a constant cell age, just before cell separation so that cells occur singly. In M. flavus, however, the time between septum formation and the related cell separation exceeded one generation time so that cells were either in pairs or tetrads. This arrangement of cells in groups is more typical of Gram-positive bacteria. The change in cell dimensions from hemispheres to spheres was also found to occur in M. flavus at a constant cell age, just before septum formation. With reference to three taxonomically unrelated bacteria, the arrangement of cells in groups is shown to result from the interrelation between growth rate and the timing of septum formation within the cell cycle.
The toxic effect of 4-chloro-2-cyclopentylphenyl β-D-galactopyranoside in lactose broth on the growth of Shigella in mixed culture with Escherichia coli
Authors: Park C. E , Stankiewicz Z. K. , Johnston M. A. , Todd E. C. D.
Published: February 2010

The addition of 1 × 10−3 M 4-chloro-2-cyclopentylphenyl β-D-galactopyranoside to lactose broth did not affect the growth of pure cultures of Shigella dysenteriae, S. flexneri, S. boydii, and S. sonnei. However, in mixed culture with Escherichia coli, none of the Shigella species grew in this medium. The release of the aglycone, 4-chloro-2-cyclopentylphenol (CPP), into the medium by E. coli was responsible for the inhibition of the Shigella. At a level of 1 × 10−4 M, CPP exerted a bactericidal effect on Shigella as well as E. coli, but a level of 4 × 10−4 M CPP was required to inhibit Salmonella. The maximum amount of CPP in the medium released by E. coli was 2.8 × 10−4 M, which exceeds the limit for growth for Shigella but is only half of the toxic level for Salmonella.
Uncoordination and recoordination in Spirillum volutans
Authors: Caraway B. H. , Krieg N. R.
Published: February 2010

The quantitative effects of several new uncoordinating agents for Spirillum volutans were studied. A new type of uncoordination, "dual-straight-tail," was described for polyethylene glycol or HgCl2. Certain agents caused a mixture of more than one type of uncoordination. Exposure of normal cells to pH 4.4 caused dual-tail uncoordination, while pH 9.9 caused dual-head. Recoordination of cells was accomplished by washing cells free of agent, application of metal-complexing agents, or, in the case of uncoordination by pH, readjustment of pH. Protein synthesis was not required for recoordination. All agents tested caused substantial decreases in oxygen consumption at their uncoordinating concentrations, but this was not the cause of uncoordination since normal coordinated states could be maintained with every cell for prolonged periods in the absence of detectable respiration, even in the presence of cyanide. Stroboscopic measurements indicated decreased flagellar rotational speeds in uncoordinated cells. In an electric field, the act of reversing polarity or of breaking or closing the circuit caused motile coordinated cells to instantly reverse whatever direction in which they had been previously swimming. Electric fields did not cause alignment of the motile spirilla.