bluuebunny/crossref_metadata_2025 huggingface dataset:
Caractères culturaux inhabituels d'une souche d'herpesvirus hominis
Authors: Daniel Philippe
Published: February 2010

A strain of herpesvirus hominis (HL 690) did not grow, at the time of isolation, on the chorioallantoic membranes of embryonated hens' eggs and induced only a slight and nonspecific cytopathogenic effect on KB cells. After four passages on hamster (BHK 21/Cl3) cells the virus caused lesions on chorioallantoic membranes and cytophathic effects on KB cells. The data indicate the need to use cells from different species before concluding a specimen is free of herpesvirus.
The serological activities of immunoconglutinin
Authors: Ingram D. G.
Published: February 2010

Immunoconglutinin is an antibody against fixed complement which appears in the serum of an animal after a strong antigenic stimulation. Using alexinated sheep red blood cells as antigen, various reactions between rabbit immunoconglutinin and complement were examined. It was shown that immunoconglutinin acted as an antibody to bring about the binding of horse, rabbit, and guinea pig complement. In the presence of hemolytic complement, immunoconglutinin had hemolysin activity.Immunoconglutinin was specifically absorbed from immune serum by using the antibody and complement present in the serum, thus demonstrating that immunoconglutinin can react with autologous complement.Rabbit sera containing heterostimulated immunoconglutinin showed an increased and prolonged bactericidal effect. It is suggested that the function of immunoconglutinin is to enhance the normal activities of complement.
Chemical composition of cell walls of Saccharomyces fragilis
Authors: Reuvers T. , Tacoronte E. , Mendoza C. Garcia , Novaes-Ledieu M.
Published: February 2010

Cell walls of Saccharomyces fragilis grown in two different media were prepared by mechanical disruption, and their chemical composition was studied. A high carbohydrate content (75–80%) was found in these walls. Glucose and mannose were represented in a ratio 1:1 in both cases; cell walls also contained a small amount of glucosamine. Sixteen common amino acids were detected in S. fragilis wall hydrolysates. One unidentified ninhydrin-positive component was present when the organism was grown in Hansen medium. A low percentage of lipid was found in both walls. The significance of all these data is discussed in the light of the difficulties encountered in the preparation and purification of walls.
The influence of temperature on the pathways of glucose catabolism in Pseudomonas fluorescens
Authors: Palumbo S. A. , Witter Lloyd D.
Published: February 2010

The influence of temperature on the pathways of glucose catabolism in Pseudomonas fluorescens has been investigated using the radiorespirometry method. When grown in continuous culture with limiting concentrations of glucose, the organism metabolized 86% of the glucose via the Entner–Doudoroff pathway at 30, 20, and 8 C. The remaining glucose, 14%, was metabolized via the hexose monophosphate pathway. When the organism was grown on non-limiting concentrations of glucose at 8 C, a major shift in pathways of glucose catabolism was observed. Fifty-seven percent of the glucose was degraded via the hexose monophosphate pathway and only 43% via the Entner–Doudoroff pathway. A change in temperature altered the pathways of glucose catabolism by regulating the growth limiting concentration of glucose rather than by directly affecting the respective enzyme activities of the pathways.
Effect of streptomycin on the phosphorus metabolism of Bacillus subtilis
Authors: Mandal Amalendu , Majumdar S. K.
Published: February 2010

Streptomycin at a dose causing decrease of growth of Bacillus subtilis strain B3 greatly affected the use of phosphorus compounds from the medium during the exponential phase of growth of the organism. Streptomycin also interfered with the accumulation of phosphate esters in the cells of B. subtilis. The accumulation of phosphate esters like fructose-6-phosphate, fructose-1,6-diphosphate, triose phosphates, phosphoglyceric acid, and phosphopyruvic acid was consistently lower in the streptomycin-treated culture throughout the entire period of cellular growth.
Anomaly in the neutralization kinetics of phages of Agrobacterium radiobacter
Authors: Roslycky E. B.
Published: February 2010

Inactivation rates of PS-192 phage of Agrobacterium radiobacter with specific antisera homologous to phage PR-1001 deviated from a first-order reaction. In an investigation of this phenomenon, several hypotheses were tested, including effect of the animal, hereditary resistance to neutralization, exhaustion of antiserum potency, combining of antibody with phage in such a way as to render neutralization-resistant complexes, a non-specific effect of the complement, and a non-immune serum factor. None of these hypotheses, however, could be corroborated experimentally. Preliminary investigation of the cationic environment showed that mono- and di-valent cations exert considerable effect on the course of neutralization of the bacteriophages studied.
Growth of Escherichia coli on some organophosphonic acids
Authors: Alam Ashraf U. , Bishop Stephen H.
Published: February 2010

Escherichia coli (ATCC No. 8739) can use a variety of alkyl and aminoalkylphosphonic acids as a source of phosphorus during growth. Chloromethylphosphonate, phenylphosphonate, hydroxymethylphosphonate, and 2-aminoethylphosphonate will act as a source of phosphorus during growth in the absence of inorganic phosphate. No growth occurs when methylene diphosphonic acid is substituted for inorganic phosphate. Cleavage of the carbon to phosphorus bond of these aromatic and substituted alkyl phosphonic acids during growth is indicated by these growth studies.
The mutation of some virulent rhizobiophages into the temperate form
Authors: Kleczkowska Janina
Published: February 2010

Lysogenic bacteria carrying temperant mutants of virulent rhizobiophages were isolated from some of the cultures in which phage resistant survivals of host bacteria had coexisted with the virulent phages for several weeks at 25°.
Berberine sulfate: antimicrobial activity, bioassay, and mode of action
Authors: Amin A. H. , Subbaiah T. V. , Abbasi K. M.
Published: February 2010

Berberine sulfate was shown to possess antimicrobial activity against a wide variety of microorganisms including Gram-positive and Gram-negative bacteria, fungi, and protozoa. The antibacterial activity against Vibrio cholerae and Staphylococcus aureus was dependent on the inoculum size of the test organism and pH of the medium. A method of microbiological assay sensitive to 5–10 μg/ml of the drug was developed. The drug was shown to exert a more rapid antibacterial activity than chloramphenicol and tetracycline on V. cholerae, the K values being 2.4 ×10−2 sec−1, 7.8 × 10−3 sec−1, and 5.2 × 10−3 sec−1 respectively. Berberine sulfate was shown to be bacteriocidal to V. cholerae and bacteriostatic to S. aureus, at concentrations of 35 and 50 μg/ml. In both these organisms concentrations of 35 and 50 μg/ml of the drug inhibited ribonucleic acid (RNA) and protein synthesis almost immediately after the addition of the drug. There was little effect on deoxyribonucleic acid (DNA) synthesis at these concentrations.
The resistance of Escherichia coli to oxytetracycline
Authors: Last Jerold A. , Izaki Kazuo , Snell J. F.
Published: February 2010

The effects of oxytetracycline on sensitive and resistant strains of Escherichia coli were studied in relation to: (1) growth of bacteria in shaken cultures, (2) incorporation of amino acids into polypeptides by cell-free extracts, (3) binding of aminoacyl-tRNA to ribosomes. Our results support the hypothesis that resistance to the antibiotic is due to impermeability of bacteria to the drug.Evidence is also presented that there is no irreversible binding of oxytetracycline at ribosomal sites involved in protein synthesis.
An improved method for the preparation of a stable noninfective western equine encephalomyelitis diagnostic antigen
Authors: Polley John R. , Guerin Muriel M.
Published: February 2010

The virus of western equine encephalomyelitis (W.E.E.) was propagated in chick embryo tissue cultures. The rates of inactivation of the infectivity and the specific antigenicity of the infected fluid by gamma irradiation were determined. It was found that it was possible to destroy the infectivity while still retaining most of the specific complement-fixing activity. No difference in the rate of inactivation of the W.E.E. virus was observed when the dose rate of gamma radiation was varied between 0.9 × 106 and 2.7 × 106 rads/hour, showing a considerable tolerance in the dose rate of the gamma cell used. The residual infectivity of incompletely irradiated samples did not undergo a significant change in titer if titrated immediately or 2 days after irradiation, so that titrations do not have to be carried out immediately after irradiation, if inconvenient. A routine noninfective W.E.E. diagnostic antigen can be prepared by this process and then concentrated if required, followed by lyophilization for stable storage. Such an antigen can be produced more readily in bulk than those prepared from infected mouse brains or allantoic fluid.
Mycoplasma-like bodies in the saliva of the Ieafhopper Macrosteles fascifrons (Stål) (Homoptera: Cicadellidae)
Authors: Raine J. , Forbes A. R.
Published: February 2010

A method of feeding leafhoppers on agar to detect microorganisms in their saliva was developed and used with groups of six-spotted leafhoppers, Macrosteles fascifrons (Stål), transmitting aster yellows and groups not transmitting the disease. Mycoplasma-like bodies ranging in size from 30 to 400 mμ were found in the saliva and salivary sheaths of both groups. The structure of the salivary sheaths is described.
Metabolism of Clostridium perfringens type A. I. Cultural conditions which provide stable cell suspensions
Authors: Groves D. J. , Gronlund Audrey F.
Published: February 2010

Media and growth conditions, which greatly suppress autolysis of Clostridium perfringens type A, are described.
Thermal stability of ribosomes from a psychrophilic and a mesophilic yeast
Authors: Nash C. H. , Grant D. W.
Published: February 2010

Ribosomes from the obligately psychrophilic yeast, Candida gelida, are rendered completely non-functional after exposure to 40 C for 5 minutes. This heat-induced impairment of ribosomal function is characterized by a reduced capacity to bind charged sRNA and is accompanied by physical degradation. Ribosomes from the mesophilic yeast, Candida utilis, however, are functionally and physically unaffected when subjected to similar treatment. The dissimilar thermal stabilities may be attributed to marked differences in the ribonucleoproteins present in the two species.
The reversal of Dalapon toxicity by microbial action
Authors: Bounds Harold C. , Magee Lyman A. , Colmer Arthur R.
Published: February 2010

A Micrococcus sp., similar to M. flavus, was found to reverse the inhibitory effects of 2,2-dichloropropionic acid (Dalapon) on an unidentified Agarbacterium sp. Neither organism could be shown to degrade the herbicide, as determined by Cl− release or disappearance of the agent from the medium. Bioassay of the filtered micrococcal broth revealed the presence of pantothenic acid. β-Alanine, valine, and alpha-ketoisovalerate could not overcome the herbicide's inhibitory effects on the Agarbacterium, but sodium pamoate produced a slight increase in growth. Calcium pantothenate (0.05 ug/ml) allowed the same amount of growth of the Agarbacterium in Dalapon medium as did the micrococcal filtrate. The finding suggests that an "associative action" of microorganisms may play an important role in microbial resistance to herbicides.
Cell division in Mycoplasma gallisepticum
Authors: Bernstein-Ziv Ruth
Published: February 2010

Cell division in cells of Mycoplasma gallisepticum strains A5969 and S6 was studied. No differences were found between the two strains.During growth young cells either increase in length, in width, or in both directions. A second bleb may develop at various sites in the cell. Division appears to be related to the position of the bleb, and may be transverse or longitudinal. In addition, a divisional form resembling "budding" occurs, which may also produce equal or unequal daughter cells. As division proceeds, new membranes are formed and the cells appear to separate.Polysomes were found in the logarithmic phase, while in the lag phase only ribosomes were observed. With the growth of the cells polysomes and ribosomes migrate to regions where protein synthesis occurs.
Toxicity and biodegradation of dihydroquercetin
Authors: Cserjesi A. J.
Published: February 2010

Growth of white-rot fungi was inhibited by dihydroquercetin (3,5,7,3′,4′-pentahydroxy flavanone) in a liquid medium, while brown-rot fungi were generally unaffected by the presence of this compound at concentrations up to 0.16%. Dihydroquercetin was recovered from the cultures of brown-rot fungi, but degraded by white-rot fungi, suggesting that the degradation products might be more toxic than dihydroquercetin itself. Among the stain and mold fungi, Chaetomium globosum reacted similarly to this flavonone as white-rot fungi, while the growth of Trichoderma virgatum and Aspergillus sydowi were similar to brown-rot fungi. Cephaloascus fragrans and Penicillium sp. tolerated dihydroquercetin in the medium, but were also able to degrade it.
Mesophilic mutants of an obligate psychrophile, Micrococcus cryophilus
Authors: Tai P-C. , Jackson H.
Published: February 2010

Several mutants with elevated maximal growth temperature (MGT) were developed from an obligate psychrophile, Micrococcus cryophilus ATCC 15174, by ultraviolet irradiation. Two of the mutants, T8 and M19, have the most similar characteristics to those of their parent. The mutants lost the ability to grow well at 0 °C and showed changes in metabolic pathways while acquiring the ability to grow at elevated temperatures. Heat resistance and deoxyribonucleic acid thermal denaturation temperature were shown to be unrelated to maximum growth temperature. The significance of the mutants is discussed.
Growth and respiration of an obligate psychrophile, Micrococcus cryophilus, and its mesophilic mutants
Authors: Tai P-C. , Jackson H.
Published: February 2010

The temperature characteristic for growth (μ) has been determined for an obligate psychrophile, Micrococcus cryophilus ATCC 15174, and its mesophilic mutants. The use of μ. for characterizing psychrophiles and mesophiles is discussed.Solute-transporting and energy-yielding systems were shown to be unrelated to maximum growth temperature.Endogenous respiration and the temperature characteristic of substrate oxidation were both found to be unsuitable as a means of characterizing mesophiles and psychrophiles. The temperature coefficient of substrate oxidation (Q10), with reference temperatures set at 10 and 30 °C is suggested for this purpose, mesophiles having a higher value than psychrophiles.
Preparation of a purified adenovirus diagnostic antigen by gel filtration
Authors: Polley John R. , Webb T. S.
Published: February 2010

Gel filtration has been investigated as a method for purifying adenovirus antigens in tissue culture fluid. It was found that by molecular sieving through the agarose Sepharose 4B, most of the infectivity, hemagglutinins, and nonspecific complement-fixing (CF) activity could be separated from a second fraction which contained some hemagglutinin but only a low titer of viable virus and from a third fraction which contained the group-specific complement-fixing antigen but was relatively free of hemagglutinin, viable virus, and nonspecific reactants.For the routine production of a noninfective, purified group-specific diagnostic antigen for adenovirus, the bulk infected fluid is inactivated by heating at 56 °C for 3 hours at pH 5.5 or by gamma irradiation with 2.5 megarads, concentrated about 20-fold by pervaporation or by pressure filtration, purified by gel filtration using Sepharose 4B, concentrated to desired potency, and then lyophilized for stable storage.
The significance of antibody to the psittacosis–L.G.V. group antigen
Authors: Wyman H. , Rigby C. , Wilt J. C. , Hildes J. A.
Published: February 2010

Antibody to the psittacosis–lymphogranuloma venereum (psittacosis–L.G.V.) group antigen was present in 88% of serum samples collected in 1967 from 100 persons at Eskimo Point, Northwest Territories (N.W.T.), thus confirming previous reports of a high incidence of this antibody in Northern residents. The present study to determine the significance of these antibodies, excluded the possibility that they had been formed in response to a heterophile antigen present in bacteria, rickettsia, or egg yolk, While the sera of Manitobans that reacted with the group antigen also reacted with a specially prepared specific antigen of psittacosis, none of the Eskimo sera that reacted with the group antigen reacted with the specific antigens prepared from psittacosis or meningopneumonitis. The antibody against the group antigen was totally adsorbed with live meningopneumonitis group antigen. These findings, plus the fact that some chlamydial diseases do not occur in the North, and that the animal reservoirs of other chlamydia do not exist in the North, limit the possible causative agents of these antibodies to ornithosis, human pneumonitis, and animal pneumonitis. Evidence suggests that a unique, endemic chlamydial agent stimulated the production of these antibodies; further work will be required to determine which particular member of the chlamydial group is responsible, and to demonstrate its reservoir.
Effects of ozone on the germination of fungus spores
Authors: Hibben C. R. , Stotzky G.
Published: February 2010

Detached spores of 14 fungi varied in germination after exposure on agar to 10 to 100 parts per hundred million (p.p.hm.) ozone for 1 to 6 h. Large pigmented spores of Chaetomium sp., Stemphylium sarcinaeforme, S. loti, and Alternaria sp. were insensitive to 100 p.p.hm. Spores of Trichoderma viride, Aspergillus terreus, A. niger, Penicillium egyptiacum, Botrytis allii, and Rhizopus stolonifer were reduced in germination primarily by 100 and 50 p.p.hm. for the longer exposures. Small hyaline spores of Fusarium oxysporum, Colletotrichum lagenarium, Verticillium atbo-atrum, and V. dahliae were the most sensitive, as their germination was prevented or reduced by most exposures to 100 and 50 p.p.hm. and occasionally reduced by doses as low as 25 p.p.hm. for 4 and 6 h. Ten parts per hundred million for 6 h had little inhibitory effect, but extended exposures up to 28 h reduced germination of A. terreus, A. niger, and P. egyptiacum spores to below 50% of the controls. The lower doses of ozone sometimes stimulated spore germination. Fungus colonies maintained in an ozone atmosphere had abnormal growth characteristics. Ozone had little inhibitory effect on air-dried spores or spores in a liquid medium.
Adaptation of an Aedes aegypti cell line to hemolymph-free culture medium
Authors: Sohi S. S.
Published: February 2010

Aedes aegypti cells (Grace's line) growing in a medium containing 5% Antheraea pernyi hemolymph (APH) and 5% fetal bovine serum (FBS) were adapted to a hemolymph-free medium. The quantity of APH was gradually substituted with an equal quantity of FBS over a 2-month period. The cells grew very slowly in the hemolymph-free medium in the beginning. However, they became adapted to it in another 8 months; after that they grew as well as the cells in medium supplemented with hemolymph.Also, these cells grew as well in medium containing Bombyx mori hemolymph as in medium enriched with APH.
Penicillinase in urine with high bacterial counts
Authors: Zemelman Raúl , Salazar Beatríz , Rodríguez Edwig
Published: February 2010

Penicillinase activity in 20 samples of urine exhibiting high bacterial counts was determined iodometrically. The enzymatic activity of 18 strains of Escherichia coli and two strains of Proteus mirabilis isolated from these samples was also determined by both the iodometric technique and a plate method. Positive results were found in 55% of the samples of urine. All the strains isolated from penicillinase-positive samples gave positive results when tested in pure cultures, whereas no penicillinase-producing strains were isolated from the samples giving negative results by the iodometric technique. Minimum inhibitory concentrations of benzylpenicillin were found to be extremely high in the strains recovered from positive samples (generally above 5000 μg/ml). The rest of the strains showed minimum inhibitory concentrations significantly lower (below 125 μg/ml). Penicillinase does not seem to exert its full activity in the urine, since quantitative results obtained with isolated strains were always higher. The hydrolysis of benzylpenicillin is inhibited when methicillin is added to the substrate.
Antimicrobial effects of anacardic acids
Authors: Gellerman Joanne L. , Walsh Nancy J. , Werner Nancy K. , Schlenk Hermann
Published: February 2010

Anacardic acids (6-alkylsalicylic acids) inhibited metabolism of Streptococcus faecalis, Bacillus subtilis, Escherichia coli, Pseudomonas fluorescens, Gyrodinium cohnii, Euglena gracilis and a white mutant of it, Neurospora crassa, Penicillium griseofulvum, Saccharomyces cerevisiae, and Candida utilis. The Gram-positive B. subtilis and S. faecalis were the most sensitive. The sensitivity of Gram-negative bacteria and of the protozoon G. cohnii increased with increasing unsaturation of the alkyl chain in anacardic acids. The latter organism was more sensitive when cultured in medium containing arginine instead of histidine.
The effect of gibberellic acid on Hansenula wingei
Authors: Makarem Emile H. , Alldridge Norman
Published: February 2010

The present study shows the influence of gibberellic acid on the budding and cell division of three strains of Hansenula wingei. Gibberellic acid at 10 μg/ml increased cell division of all the strains of H. wingei tested. The rate of budding and cell division diminished as the concentration of gibberellic acid increased over or decreased below 10 μg/ml. Also tested was the ability of gibberellic acid at a concentration of 10 μg/ml to stimulate the synthesis of deoxyribonucleic acid (DNA), ribonucleic acid (RNA), and protein contents of both haploid and diploid strains of H. wingei. The rate of DNA, RNA, and protein synthesis decreased as the concentration of gibberellic acid was increased over or decreased below 10 μg/ml.
Growth of Graphium sp. on natural gas
Authors: Zajic J. E. , Volesky B. , Wellman Angela
Published: February 2010

A fungus which grows well on a mineral salts solution with natural gas as the carbon source is described and provisionally identified as a Graphium species. Its taxonomic relation to several genera is presented. This organism was isolated from sewage after selection by enrichment techniques and continuous culture. The fermentor was operated at ambient temperatures, 28 °C ± 2, at a volume of 10 liters with a dilution rate of 10 liters/4 days to 10 liters/1.7 days. Coty's mineral salts medium gave the highest tissue yield. When the pH of the incoming mineral salts medium was decreased stepwise from 7.0 to 5.0 the pH of the reactor became self-adjusting, varying from around 2.7 to 3.5, and the dry weight of microbial tissue obtained varied from 65 to 275 mg/h. Also present in the continuous culture was an acid tolerant bacterium, which, when isolated, grew well on natural gas, methanol, and ethanol, and a strain of Trichoderma, which, when isolated, did not use natural gas as a carbon source. In mixed culture the Trichoderma is thought to grow on metabolites produced by either or both the Graphium and the acid-tolerant bacterium during oxidation of natural gas. The nature of the relationship is being investigated. The mixed culture has been under continuous cultivation for 18 months.
Pectic and cellulolytic enzymes of Stemphylium radicinum
Authors: Curren T.
Published: February 2010

Two isolates of Stemphylium radicinum grown in liquid culture produced polygalacturonase (PG), and measurable amounts of pectin methylesterase (PME) and cellulase (Cx). PG was produced inductively. Sodium polypectate was hydrolyzed more rapidly by the PG than was pectin.
Electron microscopic evidence for a double hair-like nap appearing at low frequency on Bacillus anthracis Sterne spores
Authors: Kramer M. J. , Roth Ivan L.
Published: February 2010

Electron microscopic examination of thin sections of Bacillus anthracis Sterne spores triply poststained with KMnO4, uranyl acetate, and lead citrate has indicated an unusual morphological variant. These spores are seen at very low frequency and have, in addition to the hair-like nap normally associated with the exosporium a second hairy layer which appears to originate in the spore coat complex.
Enzyme activities during the asexual cycle of Neurospora crassa. III. Nicotinamide adenosine diphosphate glycohydrolase
Authors: Stine G. J.
Published: February 2010

The level and specific activity of nicotinamide adenosine diphosphate glycohydrolase (NADase) were followed throughout the asexual cycle in Neurospora crassa. A large quantity of NADase associated with the conidia was water soluble. NADase activity rapidly disappeared from the growth medium during conidial germination and from early logarithmic mycelial growth. As the mycelia aged, the enzyme accumulated in the growth medium and in the aging aconidial conidiophores, regardless of their inability to produce conidia. Since the enzyme was synthesized as the culture aged, it appears that the conidiophores age quickly with respect to their production of NADase. Conidia produced from conidiophores of the wild-type culture contained about the same quantity of NADase as the inoculum conidia. The accumulation of NADase in the conidia of wild-type Neurospora is due to the normal differentiation of these conidia in the absence of a liquid environment. The enzyme becomes locked into the conidia being differentiated from conidiophores that contain large amounts of the NADase activity.
The effect of air pressure on the growth of Candida lipolytica on n-hexadecane
Authors: Wayman M. , Wein E.
Published: February 2010

Mass transfer of oxygen to the microbial cell is very important in hydrocarbon fermentations. One method of increasing mass transfer of oxygen is to increase its partial pressure. Increasing the total pressure of the air-feed will increase the partial pressure of oxygen, but little work has been done in this area. The present study concerns the effects of increased air pressure up to 100 pounds per square inch gauge (p.s.i.g.) on the growth of Candida lipolytica on n-hexadecane in an agitated 7-liter pressure reactor. Inhibited growth was observed with increasing pressure. Maximum cell mass yield at 100 p.s.i.g. was about one-third that at 15 p.s.i.g. Inhibition was attributed to a gaseous component fed in with the air stream.
Inhibition of pleomorphism by protein and ribonucleic acid inhibitors
Authors: Klein Deana T. , Runne Carol B.
Published: February 2010

The granular strain of Trichophyton mentagrophytes (M12-4) was grown in the presence of specific inhibitors of protein, deoxyribonucleic acid (DNA), and ribonucleic acid (RNA) synthesis. Those inhibitors which block protein and RNA synthesis inhibit mutant pleomorphic patch formation. Inhibitors of DNA synthesis had no effect on the visible expression of the mutant patches. Data presented suggest that initiation of the pleomorphic patch is not inhibited, but rather that mycelial growth is blocked.
Growth repression of Mycobacterium tuberculosis in the presence of Krebs cycle intermediates and some other substrates
Authors: Brezina O. , Drobnicová I. , Drobnica L.
Published: February 2010

Proliferation of H37Rv cells in Youmans medium without glycerol and under specified conditions was inhibited and partially stopped by addition of glycerol, glucose, lactate, pyruvate, and malate, especially when these C-sources had been added in an appropriate concentration in the initial phase of growth (24 hours after inoculation of media). Addition of one of the above substances in equal concentration but already in the logarithmic phase of growth according to character of substances did not influence the course of proliferation, or it had only a shift-down effect.
Soil fungistasis with respect to pH and profile
Authors: Schüepp H. , Frei E.
Published: February 2010

Soil fungistatic activity was determined in different soils using the sterile cellophane–agar diffusion method. Comparing 35 soil samples from eight profiles, the inhibitory effect on Trichoderma koningi was found to increase with increasing soil pH irrespective of the depth at which the soil samples were taken.The fungistatic principle of seven soils was compared using 24 test fungi. Nearly all fungi affected by soil fungistasis were more strongly inhibited with increasing soil alkalinity.Susceptibility of some fungi to the fungistatic principle varied considerably with the age of the cultures from which the spores were collected. Inhibition of germination was significantly dependent on the length of preactivation of the agar discs over the soil. In some instances the inhibitory effect was considerably reduced if the agar discs were removed onto glass for the germination test after preactivation on cellophane over soil.
Penicillium viridicatum Westling: a new source of ochratoxin A
Authors: Walbeek W. van , Scott P. M. , Harwig J. , Lawrence J. W.
Published: February 2010

Ochratoxin A has been obtained from both mycelium and culture filtrates of Penicillium viridicatum Westling grown on a yeast extract – sucrose medium. Ergosterol was also identified as a metabolite. The greatest amount of ochratoxin A was detected 9 days after inoculation. Toxin production decreased greatly after several successive subcultures. However, it was possible to obtain a strongly toxinogenic isolate again from the parent culture. Small amounts of ochratoxin A were detected in 60% whole wheat bread slices used as a substrate for P. viridicatum.
Linkage of a temperature-sensitive locus to the streptomycin region and its use in recombination studies with streptomycin mutants of Bacillus subtilis
Authors: McDonald W. C.
Published: February 2010

Transformation and transduction experiments in B. subtilis demonstrate close linkage of a temperature-sensitive mutation to the streptomycin region. Three-factor crosses locate this mutation between str and ery. Using the tms+ characteristic as the selected marker, crosses between str-d and str-r strains yield small numbers of str-s recombinants. This demonstrates the non-identical nature of the two str mutations investigated.
Plaque assay of poliovirus in plastic chambers
Authors: Chaudhary R. K. , Westwood J. C. N.
Published: February 2010

A method for the plaque assay of Poliovirus type I using plastic chambers on glass microscope slides with an agar overlay has been developed. This microtechnique offers a reliable system for plaque assays which is directly comparable with other systems. The maximum efficiency of adsorption was 80–85% and clear and countable plaques appeared within 30–34 hours. The advantages of this system include simplicity, economy of materials, and flexibility. Other applications of the technique include plaque inhibition, plaque size reduction, immunofluorescent plaque assays, and cytological studies.
Stimulation of Waitea circinata by root exudates of Pinus cembroides
Authors: Agnihotri V. P. , Vaartaja O.
Published: February 2010

Effects of root exudates from Pinus cembroides to Waitea circinata were studied by using paper chromatography. Each of 14 seedlings liberated an average of 175 μg of ninhydrin-positive substance and 133 μg of sugars in 35 days. From these, 14 amino acids, 4 sugars, and 3 organic acids were identified. The root exudate induced greatly increased mycelial growth over a wide temperature range, but sclerotia were produced only after 20 days between 15 and 20 °C. Each amino acid and carbohydrate, except threonine, valine, glycine, glutamic acid, lysine, γ-aminobutyric acid, and citric acid, stimulated vegetative growth. Neither basidia nor sclerotia developed on any nutrient medium. The sclerotia did not require exogenous nutrition for germination and initial growth. Germination percentage remained between 95 and 100 with each exudate component. All carbohydrate components, either singly or in combination, stimulated extension growth from sclerotia. Of 14 amino acids, only aspartic acid, glutamic acid, and leucine supported faster extension growth than the control (water agar). Temperature and pH influenced germination and growth, the optima being at 25 to 30 °C and pH 5 to 6.
Immunodiffusion studies on the myxoviruses. II. Identification of influenza A/PR8 precipitins in the serum of normal rabbits
Authors: Johnson C. Margaret , Westwood John C. N.
Published: February 2010

An investigation has been made to determine whether influenza virus precipitins, detected in the serum of normal rabbits, are immunoglobulins or non-specific inhibitors of virus haemagglutination. Of 12 normal rabbit sera screened by immunodiffusion reactions for the presence of these precipitins, 6 sera were found to be positive. Serum treatments for the removal of non-specific HA inhibitors, i.e. heat, periodate, trypsin, and neuraminidase, did not completely inactivate either the haemagglutination-inhibiting or the precipitating activity of the normal serum. Fractionation studies for the isolation and identification of the serum fraction responsible for the precipitating activity included DEAE-cellulose adsorption, rivanol treatment, and ammonium sulfate precipitation. The active component in the normal serum snowed a reaction of identity with specific antibodies against influenza virus contained in the gamma globulin fraction of immune serum. It is concluded that the precipitating component detected in the serum of some normal rabbits is immunoglobulin, presumably arising as a result of natural infection.
Use of Pankhurst tubes to assay acetylene reduction by facultative and anaerobic nitrogen-fixing bacteria
Authors: Campbell N. E. R. , Evans Harold J.
Published: February 2010

Pankhurst tubes are simple and inexpensive vessels in which to screen large numbers of bacterial isolates by the acetylene reduction test for nitrogen fixation. A modification is described which allows, in addition, optical density measurements of growth. The method is well suited to most probable number estimations of facultative and anaerobic nitrogen-fixing bacteria in soils and on root surfaces.
Preparation and properties of cellulases from rumen microorganisms
Authors: Krishnamurti C. R. , Kitts W. D.
Published: February 2010

The distribution of cellulase activity in the solid and liquid fractions of rumen contents collected from a fistulated steer was studied. The specific activity of cellulase in the clear supernatant of rumen fluid and in the sonicated cells suspended from the liquid fraction was 0 and 0.75 × 10−3 units/mg protein respectively against carboxymethylcellulose (CMC). On the other hand, the specific activity of the fraction obtained by ultrasonic disruption of organisms released from the solid portion of rumen contents by gentle agitation was 0.22 × 10−3, 0.19 × 10−3, and 1.10 × 10−3 units/mg protein against solka floc, avicel, and CMC respectively. Addition of autoclaved rumen fluid to the assay system resulted in a decrease in the rate of production of reducing sugars, indicating the presence of inhibitors. The cellulase exhibited a maximum activity at pH 5.5. The addition of cobalt chloride and L-cysteine resulted in an increase in cellulase activity whereas the addition of urea, D-gluconic acid lactone, sodium sulfide, and ferric chloride was inhibitory.In cellulose enrichment cultures obtained from 10−8 dilution of rumen liquor, the specific activity of cellulase in the supernatant was always less than in the fraction obtained by sonic disruption of cells attached to the filter paper. The results are discussed in relation to the localization of cellulases in rumen microorganisms.
Solubilization of autoclaved feathers and wool by myxobacteria
Authors: Martin S. M. , So V.
Published: February 2010

Of the 50 strains of myxobacteria (mainly cytophagas) tested most were able to solubilize autoclaved feathers but none attacked unmodified feathers. The strain studied most extensively rapidly solubilized up to 80% of the substrate leaving only the resistant shafts. In the absence of a readily assimilable energy source, such as glucose, about 70% of the protein nitrogen solubilized appeared as ammonia which the organism could not use. Glucose exhibited an amino acid sparing effect.
Heterophil antigens in Ehrlich ascites fluid
Authors: Eng C. P. , Hindmarsh J. A. , Morgan J. F.
Published: February 2010

Immunodiffusion and hemagglutination tests have demonstrated that antiserum against Ehrlich ascites fluid is active against tissue saline extracts and erythrocytes of the mouse, rat, guinea pig, hamster, and cat. Detailed studies have shown that cat liver extract shares a common antigen present in the Ehrlich ascites cell, normal mouse liver, and guinea pig kidney. Enzyme susceptibility and heat stability tests have indicated that the cat heterophile antigen is heat stable and protein in nature. The relationship of this new heterophile antigen with other identified heterophile antigens is discussed.
Radiation survival of bacterial spores in neutral and alkaline ice
Authors: Upadhyay J. , Grecz N.
Published: February 2010

The effect of pH values ranging from 6 to 12 on spores of Clostridium botulinum 33A exposed to 0.6–0.9 Mrad Co-60 resulted in a complex wavelike pattern of survival which was influenced by pH, temperature, and dose of radiation. Within the experimental pH range three typical survival patterns could be recognized. Pattern A (at −190 °C) showed peaks of high survival at pH 7 and 9.5 and troughs of low survival at pH 8 and 10–11. Pattern B (at −50 °C) showed a single broad peak of high survival at pH 8.5 to 9 and troughs of low survival at pH 7 and 10. Pattern C (at 0 °C) showed peaks of high survival at pH 7.5 and 10 and troughs of low survival at pH 6,9, and 11. Between the temperatures showing typical A, B, and C patterns the survival profiles indicated various degrees of transition from A to B and from B to C.These results can be tentatively explained in terms of indirect effects, viz. maximum activity of radicals such as ∙OH in the troughs and extinction of ∙OH by reaction with eaq− or H∙ at the peaks.
Effect of relative humidity on the stability of Mycoplasma pneumoniae exposed to simulated solar ultraviolet and to visible radiation
Authors: Wright D. N. , Batley G. D.
Published: February 2010

Airborne Mycoplasma pneumoniae was exposed to near ultraviolet (3000–4000 Å) light, daylight fluorescent light, or total darkness at 25%, 50%, or 95% relative humidity. Without light, survival of the organisms was good at both high and low R.H. with poorest survival occurring at 50% R.H. The effect of ultraviolet light was to decrease the survival of airborne organisms at all R.H. levels, but was most dramatically seen at 25%. The high (95%) R.H. appeared to provide some protection against ultraviolet damage. The relationship between R.H. and ultraviolet light to survival was a second order reaction and supports the theory of indirect, possibly multiple site, injury that results from ultraviolet radiation. The possibility of using a combination of conditions deleterious to survival of airborne M. pneumoniae as a means of epidemiologic control is discussed.
Studies on the taxonomy of the Myxohacterales. I. Record of Canadian isolates and survey of methods
Authors: McCurdy Howard D.
Published: February 2010

One hundred and sixty-seven pure cultures have been isolated from among 338 myxobacteria obtained from Essex county (Ontario) soil samples by various methods. The fruiting body characteristics used in the characterization of the Myxobacterales have been found to be variable and unstable. However, the order may be considered to consist of two broad groups based on vegetative cell morphology and the formation of microcysts. A proposal is made to divide the genus Chondromyces into Stigmatella and Chondromyces and to assign the latter to the family Sorangiaceae. A number of biochemical tests have been found useful in identification and some are correlated with morphological features.The paper includes 42 color photographs as an aid for other investigators in the identification of the Myxobacterales.
Blood clearance of bacteriophage ϕX 174 in mice: effect of immunosuppressive drugs
Authors: Farber Paul A.
Published: February 2010

The clearance of the bacteriophage ϕX 174 from the circulation was measured in mice. There was an initial decline of less than one log10 of virus during the first 24 hours after intravenous injection. Between 24 and 48 hours there was an accelerated phase of elimination which was considered due to the production of neutralizing antibody. Rapid clearance of virus occurred within 60 minutes in mice previously immunized with ϕX. Antibody was demonstrable by in vitro neutralization tests and was composed predominantly of 19 S immunoglobulin. Methotrexate and Cytoxan abolished the immune clearance of ϕX while Cortisone delayed the onset of accelerated clearance.
Surface characteristics of conidia from monosporous cultures of Penicillium digitatum and Aspergillus nidulans var. echinulatus
Authors: Fujii R. K. , Hess W. M.
Published: February 2010

Surface characteristics of conidia from monosporous cultures of Penicillium digitatum and Aspergillus nidulans var. echinulatus were studied by use of freeze-etch replicas. Surface configurations of coni8dia of both fungi were so variable that spore wall patterns do not appear to be consistent enough to have taxonomic significance at the strain or subspecies level.
The chemical composition of cell-wall lipopolysaccharides from Moraxella duplex and Micrococcus calco-aceticus
Authors: Adams G. A. , Quadling C. , Yaguchi M. , Tornabene T. G.
Published: February 2010

Cell wall lipopolysaccharides (LPS) prepared from oxidase-positive Moraxella duplex and from oxidase-negative Micrococcus calco-aceticus (a presumptive moraxella) contained D-glucose, D-galactose, glucosamine, galactosamine, lipid A, ethanolamine, fatty acids, phosphate, and protein. The lipid A moieties prepared from the LPS fractions were composed primarily of hexosamines, ethanolamine, fatty acids, and phosphate with minor amounts of the other LPS constituents. The LPS from M. duplex and M. calco-aceticus had the same neutral sugar composition but differed markedly in their hexosamine composition. Galactosamine was the major hexosamine component of M. duplex; also present was an unidentified amino sugar and a small amount of mannosamine. In contrast, glucosamine was the major hexosamine component of M. calco-aceticus with a lesser amount of galactosamine and no mannosamine. The presence of galactosamine as the major component of the lipid A of M. duplex suggests that this fraction has a novel structure which differs from the poly-D-glucosamine 'backbone' structure assigned to lipid A. The fatty acid compositions of the lipid A from the two species were mutually similar and consisted mainly of hydroxylauric, hydroxymyristic, and C17-cyclopropane fatty acids. The LPS fractions of the two organisms studied resemble that of Neisseria catarrhalis and differ from those of the true neisserias.
Regulation of proteolytic enzyme production by Aeromonas proteolytica. I. Extracellular endopeptidase
Authors: Litchfield Carol D. , Prescott J. M.
Published: February 2010

The production of extracellular endopeptidase by Aeromonas proteolytica Merkel et al. was found to be influenced by a number of nutritional factors. An inverse relationship existed between endopeptidase synthesis and growth in media containing increasing quantities of asparagine. This effect was accentuated by the individual addition of glycerol, glucose, sucrose, or acetate as supplemental carbon sources. The addition of small quantities of complex mixtures of peptides to growth media containing either acid-hydrolyzed casein or asparagine as the organic component greatly stimulated endopeptidase synthesis. The data suggest that endopeptidase synthesis is repressed when A. proteolytica is grown in the presence of certain individual amino acids, that glycerol and some other easily metabolized compounds cause catabolite repression of endopeptidase synthesis, and that endopeptidase production is stimulated by peptides of unknown identity.
Observations on chlamydospore production by Fusarium in a two-salt solution
Authors: Qureshi A. A. , Page O. T.
Published: February 2010

An isolate of Fusarium oxysporum grown in a solution of monobasic potassium phosphate and magnesium sulfate rarely produced chlamydospores. However, when the salt solution was amended with 0.125 mg to 2.0 mg per liter of either glucose or magnesium carbonate, there was an abundant production of chlamydospores within 3 to 4 days after inoculation. While an organic or inorganic source of carbon stimulated chlamydospore formation, repression of chlamydospore production occurred with glucose and magnesium carbonate levels above 2.0 mg per liter. The addition of either an ammonium or nitrate source of nitrogen to the salt solution did not produce additional chlamydospores.
Mode of action of the alpha toxin of Staphylococcus aureus
Authors: Wiseman G. M. , Caird J. D.
Published: February 2010

Rabbit erythrocytes treated with the alpha toxin of Staphylococcus aureus, strain "Wood-46", liberate substances which contain nitrogen, absorb at 280 mμ, and react with Folin phenol reagent. The susceptibility of different erythrocyte species to alpha toxin is correlated with (a) the quantity of reaction products released by toxin from the cells and (b) the degree of natural proteolytic activity possessed by the cells. Alpha toxin was, however, without effect upon albumin, fibrinogen, casein, and hemoglobin even when these proteins had been denatured with urea. In view of the evidence, it is suggested that the toxin is secreted by the Staphylococcus as an inactive protease which must be activated by another protease. The degree of activity of this protease in various red cell species would explain their differential sensitivity to alpha toxin.
Inhibition of the amino acid induced initiation of germination of bacterial spores by chlorocresol
Authors: Sierra Gonzalo
Published: February 2010

The initiation of germination of Bacillus subtilis spores in complete medium and in phosphate buffer plus the enzyme subtilopeptidase is inhibited by chlorocresol, but the activity of the enzyme alone is not. This suggests that proteolytic activity is not the primary site of inhibition. Germination of spores of this organism can be initiated with one of each of five amino acids, viz. L-alanine, L-cysteine, L-valine, L-leucine, and L-isoleucine. The germination initiated by these amino acids is reversibly inhibited by chlorocresol. These results strongly suggest that the inhibitor prevents the initiation of germination of bacterial spores at the level of amino acid use, both in complete medium and with subtilopeptidase.