bluuebunny/crossref_metadata_2025 huggingface dataset:
Psychrotrophic Gram-positive bacteria: temperature effects on growth and solute uptake
Authors: Wilkins P. O.
Published: February 2010

The effect of temperature on growth rate, uptake of 2-deoxyglucose, and uptake and incorporation of L-leucine is described for six Gram-positive, nonsporing bacteria. The organisms, designated as psychrotrophs because of their ability to grow at 10C, are Listeria monocytogenes, Erysipelothrix rhusiopathiae, Microbacterium thermosphactum, Brevibacterium linens, Lactobacillus buchneri, and Streptococcus faecalis. The complexity of the results illustrates the difficulty of choosing simple criteria for comparing temperature responses of bacteria. However, L. monocytogenes, E. rhusiopathiae, and M. thermosphactum can be grouped together on the basis of low temperature coefficients (less than 1.8) between 10 and 20C for 2-deoxyglucose uptake. This supports the conclusion that cold-resistant sugar-transport systems are among the fitness traits that permit bacteria to grow at low temperatures.
Modification of the proteolytic digestibility of Neurospora pyruvate kinase by substrates and allosteric ligands
Authors: Kapoor M.
Published: February 2010

Neurospora pyruvate kinase was protected by the substrates PEP and ADP and an allosteric effector FDP against inactivation by pronase. Alteration of proteolysis rates in the presence of these ligands is interpreted to be due to the existence of distinct conformational states. Protein fluorescence of native pyruvate kinase was quenched by the allosteric effector to an extent of about 50%. Fluorescence behavior of the enzyme in the presence of different ligands was consistent with the conclusions of proteolysis experiments.
Antigenic comparison between in vivo and in vitro grown tubercle bacilli
Authors: Turcotte R.
Published: February 2010

Water-soluble extracts of in vivo grown tubercle bacilli were found to have a lower carbohydrate content, a reduced number of antigenic components, and a weaker ability for detecting hemagglutinating antibodies in the sera of tuberculous patients than similar extracts prepared from the same strain but cultured in artificial medium.
The phyloantigenic position of nocardiae revealed by examination of cytoplasmic antigens
Authors: Kwapinski J. B. G. , Kwapinski Elke H. , Dowler Judy , Horsman G.
Published: February 2010

Immunophylogenic relationships of nocardiae to other microorganisms were investigated by means of the immunodiffusion procedures, using 493 cytoplasm preparations and 218 anticytoplasm sera. The cytoplasm antigens of nocardiae were found mainly to be immunologically related to the saprophytic and scotochromogenic mycobacteria, as well as to the streptomycetes possessing the cytoplasmic determinant a. Only a few species of nocardiae cross-reacted with the anticytoplasm sera against Actinomyces israelii, Micromonospora, and Micropolyspora; but none was found to be related directly to the cytoplasm antigens of Eubacteriales. It is suggested that the nocardiae evolved at a later stage than the streptomycetes and candidas through which they are indirectly related to the Eubacteriales.
Modification of the exogenous carbon and nitrogen requirements for chlamydospore germination of Fusarium solani by contact with soil
Authors: Griffin G. J.
Published: February 2010

After exogenous carbon-independent macroconidium germination by Fusarium solani at 1 × 104 conidia/ml in axenic culture, chlamydospores were formed terminally on germ tubes. Low chlamydospore germination was supported under axenic conditions by 0.004 ng C/spore (calculated value), supplied as ethanol, or by 0.04 ng C/spore, supplied as glucose or several other sugars. Chlamydospores in direct contact with a nonsterile loamy fine sand soil (6.2 μg NH4+-N and 7.1 μg NO3−-N/g soil) had a greater exogenous carbon requirement and did not germinate until 2.0 ng glucose-C/spore was supplied. Supplemental exogenous nitrogen, added as NH4Cl, had little or no influence on percentage of germination at the levels of exogenous carbon supporting low germination, both in soil and in axenic culture. However, increasing the amounts of glucose plus NH4Cl supplied per spore increased percentage of chlamydospore germination more than increasing the amount of glucose alone for both soil and axenic systems. In axenic culture, complete germination was observed at 2.0 ng C plus 0.13 ng N/spore. Greater than 90% germination occurred for chlamydospores in contact with soil at the highest glucose plus NH4Cl level examined (200 ng C plus 13 ng N/spore), but not in glucose alone. Sterile acid-washed sand did not have a similar adverse effect on chlamydospore germination. Chlamydospores were nearly 100% germinable after 1 year of incubation in an inorganic salts medium under axenic conditions.
Growth inhibition of Escherichia coli strain 82/r by d-camphor
Authors: Cardullo Maria A. , Gilroy James J.
Published: February 2010

A temporary growth inhibition of Escherichia coli resulted from exposure to d-camphor at concentrations ranging from 650 to 1100 μg/ml. The duration and intensity of inhibition varied as a function of d-camphor dose. Bacteriostatic effects produced by 850 μg/ml were non-selective and included a suspension of cell division, an increase in cell size, and a simultaneous suspension of DNA, RNA, and protein biosyntheses. These effects were in evidence 10 min after the addition of d-camphor and persisted for one and a half to two generations. Volatilization of d-camphor during and subsequent to this period of growth inhibition was negligible. d-Camphor reduced the surface tension of the culture medium from 74 to 58 dyn/cm. However, leakage of intracellular contents, as assayed by absorbance at 260 nm, was not observed in d-camphor inhibited cells. Furthermore, lowering the surface tension to 58 dyn/cm with Tween-80 failed to inhibit growth. No other physical changes were observed in d-camphor containing growth medium which would account for growth inhibition. The simultaneous suspension of DNA, RNA, and protein biosyntheses suggests that d-camphor interferes with a basic metabolic function upon which all these biosynthetic processes depend.
Numerical taxonomy of Nocardia
Authors: Kurup P. V. , Schmitt J. A.
Published: February 2010

One hundred and seventeen features each for 157 strains belonging to the species Nocardia asteroides, N. brasiliensis, N. caviae, N. madurae, N. pelletieri, and N. dassonvillei and Streptomyces somaliensis were studied. The data were subjected to computer analysis, which included calculating S-value matrix, link sort and clustering, feature frequency sort, and median organism calculation. Of the 157 strains studied, 96 strains formed seven distinct groups, whereas the other strains remained unclustered or presented irregular groupings. The seven groups represented N. asteroides (four groups), N. caviae, N. brasiliensis, and N. madurae. Group II of N. asteroides corresponds to N. farcinica group of Tsukamura. The results are discussed and compared with those of other workers.
An efficient ultrafiltration method for enterovirus recovery from ground beef
Authors: Konowalchuk Jack , Speirs Joan I.
Published: February 2010

An efficient and simple method is described for recovering coxsackievirus B5 from a 100-g sample of ground beef. After extraction of virus from the meat, the sample is clarified by a simple acid–base treatment enabling concentration of virus by ultrafiltration. Virus recoveries with this method, enumerated as plaques, averaged about 67%.
Effect of aldehyde fixatives on the adenosine phosphatases and ultrastructure of Vitreoscilla
Authors: Burnham Jeffrey C. , Hageage Jr. George J.
Published: February 2010

A variety of aldehydes used in electron cytochemistry including glutaraldehyde, glycidaldehyde, acetaldehyde, and methanol-free formaldehyde were examined for their inhibitory effect on the adenosine phosphate hydrolases of Vitreoscilla species. Enzyme inhibition increased with increasing aldehyde concentration. Of the aldehydes tested glycidaldehyde and acetaldehyde were least inhibitory for both adenosine diphosphatase and adenosine triphosphatase activity. Significantly, a 1% concentration of glutaraldehyde inhibited over 80% of the activity of both enzymes. Inhibition by all fixatives was variably decreased by the addition of 8% sucrose. Electron-microscopic examination of Vitreoscilla species fixed with the various aldehydes revealed that both acetaldehyde and glycidaldehyde followed by osmium tetroxide postfixation gave results comparable with glutaraldehyde–osmium tetroxide fixed cells.
Enzymes of intermediary metabolism of Butyrivibrio fibrisolvens and Ruminococcus albus grown under glucose limitation
Authors: Kistner A. , Kotzé J. P.
Published: February 2010

A survey was made of enzyme activities in cell-free extracts prepared from one strain each of Butyrivibrio fibrisolvens and Ruminococcus albus, two anaerobic cellulolytic rumen bacteria, which had been grown in continuous culture on a defined medium under glucose limitation. In both organisms the enzymes of the glycolytic sequence up to the cleavage of hexosediphosphate were demonstrated, except that 6-phosphofructokinase activity in B. fibrisolvens was barely measurable. Instead, 1-phosphofructo-kinase was found in this organism. The role of this enzyme in glucose-grown cells is uncertain. Phosphopyruvate hydratase and pyruvate kinase could not be detected in R. albus extracts and their activities were extremely low in B. fibrisolvens, thus posing a problem as to pyruvate production in these organisms. At least part of the tricarboxylic acid cycle appeared to be functional in both organisms.Since several of the enzymes of this cycle in B. fibrisolvens were NADP-dependent, rather than NAD-dependent, and other workers have shown that fumarate reductase activity exceeds succinate dehydrogenase activity by more than 3:1, it is suggested that the tricarboxylic acid cycle may operate as a reductive cycle in this organism. Both organisms possessed fairly high activities of glutamate dehydrogenase and aspartate aminotransferase. The information obtained is inadequate to map out the pathways leading to the main end products of glucose fermentation.
Fluorescence microscopy of Douglas fir foliage epiflora
Authors: Bernstein Mary E. , Howard H. M. , Carroll G. C.
Published: February 2010

Douglas fir needles stained with the fluorescent dye, primulin, were observed microscopically using epiillumination with a mercury arc light source. Microorganisms fell into three categories: algae, which exhibited primary fluorescence; actinomycetes and fungi, which exhibited the secondary fluorescence of the adsorbed dye; and darkly pigmented fungi, which appeared black on the background of the fluorescing Douglas fir needle. A scanning electron micrograph is included for the purposes of comparison.
Carbohydrate metabolism in Acanthamoeba castellanii. 1. The activity of key enzymes and [14C]-glucose metabolism
Authors: Prescott Lansing M. , Hoyme Harold E. , Crockett Darlene , Hui Elena
Published: February 2010

The specific activities of a number of the key enzymes involved in carbohydrate metabolism in Acanthamoeba castellanii (Neff clone I–12) have been determined. The following Embden–Meyerhof and pentose phosphate pathway enzymes were present: glucose-6-phosphate dehydrogenase, 6-phosphogluconate dehydrogenase, hexokinase, phosphofructokinase, hexose diphosphatase, aldolase, glyceraldehydephosphate dehydrogenase, pyruvate kinase, and pyruvate-phosphate dikinase. The following tricarboxylic acid cycle enzymes were also found: citrate synthase, aconitase, isocitrate dehydrogenase, succinate dehydrogenase, fumarate hydratase, and malate dehydrogenase. The degradation of glucose-U-14C to 14CO2 was examined. Aerobic 14CO2 production from glucose-U-14C was 3.4-fold greater than anaerobic production. The data provide further evidence that the Embden–Meyerhof, pentose phosphate, and tricarboxylic acid cycle pathways are probably functional in A. castellanii.
Pyruvic decarboxylase and acetoin formation in Athiorhodaceae
Authors: Qadri S. M. Hussain , Hoare D. S.
Published: February 2010

Studies with cell-free extracts of Rhodopseudomonas palustris strain Q showed that under anaerobic conditions pyruvate was decarboxylated with the stoichiometric formation of carbon dioxide. Other products of the reaction include acetaldehyde and acetoin (acetyl methyl carbinol), indicating the presence of pyruvic decarboxylase. A survey of purple non-sulfur bacteria demonstrated that pyruvic decarboxylase was also formed by R. gelatinosa and R. capsulata and Rhodospirillum molischianum but not by R. rubrum and R. spheroides and Rhodomicrobium vannielii. The enzyme had an optimum pH of 6.25 and an apparent Km of 1.22 × 10−2 M in potassium phosphate buffer (50 mM) at 30C. Pyruvic decarboxylase in photosynthetic bacteria required only thiamine pyrophosphate as a cofactor and it differed in this respect from the enzyme in yeast and in other bacteria which required divalent metal ions as well. Acetoin formation in the Athiorhodaceae, like that in yeast but unlike that in most bacterial species, involved the formation of acetaldehyde from pyruvate.
Temperature-gradient incubator for the growth of Clostridia
Authors: Matches Jack R. , Liston J.
Published: February 2010

A temperature-gradient incubator was constructed and used for the growth of Clostridia. With this instrument the minimum, optimum, and maximum temperatures can be obtained for 12 organisms at one time. The incubator can also be adjusted for psychrophiles, mesophiles, and thermophiles.
Comparisons of nitrogen fixation estimates in soybeans by nodule weight, leghemoglobin content, and acetylene reduction
Authors: Johnson H. S. , Hume D. J.
Published: February 2010

Nodule leghemoglobin content, acetylene reduction rates, and nodule weight determinations were made during an entire growth period of soybean (Glycine max (L.) Merr. cv. Altona) plants grown under field conditions. High correlations within most sampling dates were found between each pair of possible comparisons of these indicators of nitrogen fixation.Rates of conversion of acetylene to ethylene per milligram leghemoglobin constantly decreased during the growing season, whereas leghemoglobin content per gram nodule fresh weight remained relatively constant. These results indicate that leghemoglobin content of nodules could be used to compare rates of nitrogen fixation in plants of a soybean cultivar at similar stages of development but should not be used to compare fixation rates in plants at different stages in ontogeny.
The decarboxylation of 6-methylsalicylic acid by Valsa friesii
Authors: Slater G. P. , Child J. J. , Hogge L. R.
Published: February 2010

Valsa friesii decarboxylates 6-[14C] methyl-[1,3,5-14C] salicylic acid to give m-cresol containing 71–81% of the original radioactivity. This indicates that 6-methylsalicylic acid can function as an efficient precursor of m-cresol.
DNA-dependent RNA polymerase in germinating bean rust uredospores
Authors: Manocha M. S.
Published: February 2010

The multiple forms of DNA-dependent RNA polymerase normally obtained from eukaryotic cells are not found in the germinating uredospores of bean rust. Only one fraction peak of the enzyme is obtained after ammonium sulfate precipitation and column chromatography on DEAE-Sephadex (A-25). The enzyme of the germinating uredospores resembles RNA polymerase of procaryotic origin in its sensitivity to rifampicin, and in its requirements for a DNA template and for all four nucleoside triphosphates.
The effect of light on the antibacterial activity of β-thujaplicin
Authors: Coombs R. W. , Trust T. J.
Published: February 2010

β-Thujaplicin solutions were shown to lose antibacterial potency after irradiation by laboratory lighting.
Intracellular concentrations of Na+, K+, and Cl− of a moderately halophilic bacterium
Authors: Masui Masamiki , Wada Sumi
Published: February 2010

The intracellular concentrations of Na+, K+, and Cl− of an unidentified moderately halophilic bacterium were determined. When the cells were grown at a late linear growth phase in a chemically defined medium containing 1, 2, or 3 M NaCl and 5.5 mM K+, the intracellular Na+ concentration (0.90–1.15 M) was independent of the Na+ in the medium. The K+ and Cl− concentrations were roughly on the same levels, respectively (0.67–0.89 M K+; 0.70–0.98 M Cl−). The Na+ and K+ per gram protein of the whole cells were 3.85 mmol and 2.96 mmol, respectively. When the cell envelope was incubated in a 2 M NaCl solution containing 5.5 mM K+ and 0.1 mM Mg2+, the Na+ concentration in the cell envelope was very high (6.49 mmol per gram protein) and K+ was concentrated up to about 41 times of the external K+ (0.36 mmol per gram protein). The high Na+ content of the isolated cell envelope may serve as one of the keys to elucidating a role of Na+ for the maintenance of the cell rigidity in this bacterium.
Leptospiral taxonomy by pyrolysis–gas–liquid chromatography
Authors: Reiner E. , Hicks J. J. , Sulzer C. R.
Published: February 2010

Current methods of leptospiral taxonomy depend largely upon serological procedures, which are frequently erroneous.During the search for a more stable classification schema, the pyrolysis–gas–liquid chromatography (PGLC) method was tried and shown to be effective in differentiating common strains of leptospires.In this study, we made a preliminary pyrolysis–gas–liquid chromatography investigation on 16 coded samples of leptospires. Results correlated positively with serological classifications. An additional 12 authenticated strains were examined. These represented the most common and important serotypes. The 12 strains were grown on Ellinghausen's medium. They were isolated, washed, and killed before lyophilization. Each sample of dried cells was weighed and subjected to PGLC. Each strain gave its own individual profile of peaks ("fingerprint"). All strains could be differentiated and identified by their fingerprints.
The bovine alveolar macrophage. 1. Isolation, in vitro cultivation, ultrastructure, and phagocytosis
Authors: Fox M. L.
Published: February 2010

The bovine alveolar macrophage (BAM) was isolated in large numbers from lung washings and could be cultivated in vitro up to 63 days in medium 199, 20% foetal calf serum (FCS). Freshly isolated cells examined by electron microscopy (EM) were similar to those of the mouse. Cultured BAM prepared for EM were larger than fresh cells and contained discrete packets of homogenous material, possibly lipid. The BAM phagocytosed Staphylococcus aureus (FDA209P, type 42D) but the percentage of cells phagocytosing was reduced when FCS was not present, when cells were infected for 30 min compared with 45 min and when 2 × 107 CFU/ml compared with 2 × 108 CFU/ml were used to infect the cells.
Purification and characterization of Pseudomonas aeruginosa alkaline phosphatase
Authors: Day D. F. , Ingram J. M.
Published: February 2010

Alkaline phosphatase and a subunit form of the enzyme have been isolated from Pseudomonas aeruginosa. The enzyme is pure as judged by molecular-sieve chromatography, sodium dodecyl gel electrophoresis, and ultracentrifugation. The enzyme possesses the following properties: (a) existence of three forms: monomer mol. wt. 39 000, dimer mol. wt. 68 000, and tetramer mol. wt. 139 000; (b) pH optimum 10.5; (c) Michaelis constant Km = 6.6 × 10−5 M p-nitrophenyl phosphate; and (d) energy of activation 5647 cal/mol. Amino acid analysis indicates a protein that is hydrophobic. Its physical behavior in solution supports this conclusion. These results explain the observed association of alkaline phosphatase and lipopolysaccharide and substantiate the current theory that the alkaline phosphatase of P. aeruginosa is bound to the outer cell wall in vivo.
L-Asparaginase production during static incubation of aerobically grown Escherichia coli B
Authors: Boeck L. D. , Ho P. P. K.
Published: February 2010

Glucose, galactose, or pyruvate independently supported biosynthesis of 1.5–2.6 IU/ml of antilymphoma L-asparaginase during static incubation of aerobically grown E. coli B cells. Fructose, lactate, and other compounds did not produce enzyme levels in excess of 0.12 IU/ml. Asparaginase synthesis by cells incubated in the presence of either glucose or pyruvate was inhibited by fluoride, iodoacetate, and sulfite. Amino acid analysis of the modified trypticase soy broth (MTSB) medium, used for aerobic cell proliferation and subsequent enzyme synthesis during static incubation, permitted development of a chemically defined (CD) medium. Washed cells, grown aerobically in the MTSB medium, produced equivalent quantities of L-asparaginase in both the MTSB and CD media. Low levels of chloramphenicol or puromycin reduced enzyme synthesis by as much as 95%.
Localization of adenosine triphosphatase activity in motile bacteria
Authors: Vaituzis Z.
Published: February 2010

Cytochemical studies on motile bacteria revealed magnesium-dependent adenosine triphosphatase (ATPase) activity at the membranous sites of flagellar origin. The studies were done on bacteria representing three types of flagellation, namely, peritrichate, lophotrichate, and monotrichate. Escherichia coli and S. serpens showed a uniform distribution of ATPase reaction products throughout the periplasmic space. In B. licheniformis and V. metchnikovii the reaction products were found in the cytoplasm accumulated in areas where flagella originate.
Growth of Streptococcus cremoris and Streptococcus lactis in a chemostat. Production of cells and survival of bacteria during frozen storage
Authors: McDonald I. J. , Reiter B. , Rogers P. L.
Published: February 2010

Streptococcus cremoris HP and Streptococcus lactis 829 were grown in chemostats in tryptone yeast extract broth and in supplemented 2% skim milk medium. In both media, lactose was the limiting nutrient. Cultures were grown at various dilution rates in media poised at constant pH and temperature and also at constant dilution rates in media controlled at different pH levels and temperatures. The effects of the various conditions of growth on production of bacteria, viable counts, and acid-producing activities of cells and on the ability of bacteria to survive subsequent frozen storage were determined. None of the conditions of growth tested had very pronounced effects on the ability of cells to survive or on the inability of cells to retain acid-producing activity after being frozen at −70 °C and stored at −40 °C.
Effect of metabolic inhibitors on germination and outgrowth of Saccharomyces cerevisiae ascospores
Authors: Rousseau Paul , Halvorson Harlyn O.
Published: February 2010

The germination and outgrowth of Saccharomyces cerevisiae ascospores were studied in presence of different glycolytic, electron transport, oxidation, and macromolecular synthesis inhibitors. Fluoride did not prevent germination and outgrowth and cyanide inhibited O2 uptake by only 50%. Dinitrophenol was completely inhibitory to O2 consumption, CO2 production, and germination, whereas other inhibitors partially affected these parameters. Cycloheximide decreased the rate of O2 uptake and CO2 evolution, and prevented outgrowth. High glucose concentrations led to a gradual inhibitory effect on respiration as outgrowth proceeded.
A chemically defined medium for the production of staphylococcal beta hemolysin
Authors: Sharma Brahma S. , Haque Riaz-ul
Published: February 2010

A synthetic medium, containing L-proline, glycine, L-arginine, L-cystine, L-glutamine, L-histidine, L-isoleucine, L-leucine, L-lysine, L-methionine, L-phenylalanine, nicotinamide, thiamine, glucose, sodium citrate, Na2HPO4, KH2PO4, (NH4)2SO4, MgSO4∙7H2O, FeSO4∙7H2O, and CaCl2∙2H2O, was developed. It supported growth and beta hemolysin production by the 681C strain of Staphylococcus aureus when the culture was incubated under carbon dioxide. L-Threonine, L-tyrosine, i-inositol, folic acid, riboflavin, pyridoxal HCl, choline Cl, and D-Ca pantothenate were added for obtaining good growth and toxin formation under air. L-Proline, L-glutamine, and L-cystine were the absolute requirements for the production of beta hemolysin under carbon dioxide. Carbon dioxide stimulated the production of beta hemolysin, but invariably resulted in lower cell yield.
Oxidation of n-alkanes by Cladosporium resinae
Authors: Walker J. D. , Cooney J. J.
Published: February 2010

Cells of two hydrocarbon-using strains of Cladosporium resinae grown on glucose oxidize hydrocarbons without a lag when transferred to dodecane, hexadecane, or their primary alcohols, aldehydes, or acids. Cycloheximide does not limit oxygen uptake when cells are transferred from glucose to dodecane or hexadecane. Isocitrate lyase levels are not higher in alkane-grown cells than in glucose- or glutamic acid-grown cells. Glucose-grown cells have higher [Formula: see text] values than hydrocarbon-grown cells when placed on dodecane or hexadecane. Thus, n-alkane-oxidizing enzymes are constitutive in C. resinae. Cells oxidize dodecanal and hexadecanal though they do not grow on them. Whole cells and cell-free preparations oxidize dodecane, hexadecane, and their primary alcohols and aldehydes, indicating that the oxygenated compounds may be intermediates in alkane oxidation. Hexane, which supports little growth, inhibits oxygen uptake of whole cells below the endogenous level, as do hexanol and hexanal. although cell-free preparations oxidize all three six-carbon compounds. Hexane inhibits oxygen uptake on hexadecane. Therefore, hexane does not appear to be transported into cells and may interfere with membrane function.
A new technique for obtaining surface culture of mycobacteria on liquid medium
Authors: Carrière J. , Diena B. B. , Wallace R.
Published: February 2010

A new technique for obtaining surface culture of mycobacteria on liquid media using a small stainless steel bridge supporting a piece of cellulose filter is described. Growth from cultures on solid media was used as inoculum. Several strains of mycobacteria have grown good surface pellicles by this method.
Toxic and immunological differences among lipopolysaccharides from Thiobacillus ferrooxidans grown autotrophically and heterotrophically
Authors: Vestal J. R. , Lundgren D. G. , Milner K. C.
Published: February 2010

Lipopolysaccharides (LPS) extracted from Thiobacillus ferrooxidans grown on ferrous iron, elemental sulfur, or glucose as energy source were studied for general chemical composition, toxicity, and antigenic or immunogenic properties. LPS from iron-grown cells (Fe-LPS) and from glucose-grown cells (Glu-LPS) had similar chemical composition, but that from sulfur-grown cells (S-LPS) differed significantly, especially in content of hexosamine, 2-keto-3-deoxyoctonate, and heptose. All had weak to moderate endotoxic properties, but Fe-LPS was considerably more active than the others in the several assays performed. S-LPS was very weakly immunogenic; the other two stimulated strong antibody responses in rabbits. Immunodiffusion tests in agar gel revealed marked differences among the LPS antigens of cells grown with different energy sources.
Antibacterial activity of β-thujaplicin
Authors: Trust T. J. , Coombs R. W.
Published: February 2010

The cedar extractive β-thujaplicin was shown to inhibit the growth of a wide variety of bacterial species, and to be bactericidal for several species. The compound caused the lysis of cells of several species of Gram-negative bacteria. The antibacterial activity of β-thujaplicin was quantitated by agar diffusion and tube-dilution assays, and shown to be less potent than sodium penicillin G and tetracycline hydrochloride.
Biological production of 5-methylthioribose
Authors: Schroeder Hartmut R. , Barnes C. J. , Bohinski R. C. , Mallette M. F.
Published: February 2010

Production of methylthioribose by Escherichia coli was investigated under various growth conditions using sulfate as the exogenous source of sulfur. Methylthioribose was shown by tracer and chromatographic methods to be a normal biosynthetic product secreted into the medium and accumulated there. Production of [35S]-methylthioribose decreased by dilution of the radioactivity as total inorganic sulfate increased in a dense suspension of cells preincubated in sulfate-limiting medium. Variations in initial inoculum size had little effect on yield of this product.Formation of methylthioribose increased with decreasing levels of nitrogen under a sulfur deficiency, with decreasing levels of sulfur under a nitrogen deficiency, and with decreasing levels of phosphorus under a combined deficiency of sulfur and nitrogen. Methylthioribose increased in the alcohol-soluble, sulfur-containing fraction on prolonged incubation in phosphate-deficient, sulfate-deficient, and phosphate–sulfate deficient media. In the last two systems methylthioribose made up nearly 100% of the total fraction.In a survey of microorganisms using sulfate as the major source of sulfur, Escherichia coli produced methylthioribose to the greatest extent. Aerobacter aerogenes, Clostridium pasteurianum, and Saccharomyces cerevisiae produced only 2–3% as much. Bacillus subtilis, Staphylococcus aureus, Lactobacillus acidophilus, and Pseudomonas aeruginosa did not form detectable amounts of methylthioribose under conditions of this study.
Ultrastructural studies on the fate of group B meningococci in human peripheral blood leukocytes
Authors: DeVoe I. W. , Gilchrist J. E. , Storm D. W.
Published: February 2010

Viable, virulent Neisseria meningitidis were rapidly phagocytized by human peripheral blood leukocytes in the presence of 10% autologous blood plasma. Bactericidal activity was detected in the three plasma concentrations tested; however, no loss of viability was observed in 10% plasma during the time required for leukocyte loading. Electron micrographs taken after phagocytosis revealed that most intracellular bacteria were rapidly destroyed; however, some intracellular meningococci remained structurally intact through the 6-h duration of the experiments. Some leukocyte lysis was observed in samples taken 30 min after leukocyte loading. This lysis resulted in the release of apparently intact meningococci, as well as debris from bacteria in various stages of disintegration. Such debris always contained meningococcal ghosts in which the cytoplasmic membrane and outer wall membrane appeared relatively intact. Cells and debris released from lysed leukocytes were enclosed in a membranous sac, presumably the membrane of the phagocytic vacuole.
Virulence to cotton and tolerance to sanguinarine among Verticillium species
Authors: Howell Charles R. , Bell Alois A. , Stipanovic Robert D.
Published: February 2010

Seventy isolates of Verticillium dahliae, five isolates of Verticillium albo-atrum, and one isolate each of Verticillium nigrescens, Verticillium nubilum, and Verticillium tricorpus were compared for virulence to cotton and sensitivity to the alkaloid sanguinarine. Virulence of the V. albo-atrum and V. dahliae isolates to cotton was correlated with their growth rates on media containing sanguinarine. In the presence of sanguinarine 24 defoliating isolates all developed a blue fluorescence, which indicates detoxification to dihydrosanguinarine. Only 10 of 51 mild to moderately virulent strains fluoresced blue under the same conditions. Initial rates of uptake of sanguinarine and its toxicity to conidia was greater at pH 6.5 than at 4.5. After 18 h at pH 4.5, isolates tolerant to the alkaloid had removed 4–5 times as much sanguinarine from the medium as sensitive isolates; at pH 6.5 the amount of sanguinarine uptake was similar for all isolates. Uptake of sanguinarine from the medium occurred concurrently with an increasing blue fluorescence of intracellular areas in sanguinarine-tolerant isolates. These tolerant isolates of V. albo-atrum and V. dahliae appear to detoxify sanguinarine and accumulate the blue-fluorescent dihydrosanguinarine. A similar system may occur in the cotton – V. dahliae host–parasite relationship.
Aflatoxin and anthraquinone biosynthesis by nitrosoguanidine-derived mutants of Aspergillus parasiticus
Authors: Detroy R. W. , Freer S. , Ciegler A.
Published: February 2010

The mutagen N-methyl-N′-nitro-N-nitrosoguanidine (NG) was shown to produce mutants of Aspergillus parasiticus NRRL 2999 that have an altered secondary biosynthesis capacity and nutritional requirements. Incubation of A. parasiticus (1 × 108) spores in 0.02% nitrosoguanidine for 60 min resulted in induced nutritional auxotrophs to a maximum frequency of 8% at 5% survival. Some 0.5% of the 5% survivors lacked the ability to synthesize aflatoxin; however, no other fluorescent metabolites were detected from these mutants. Another group of mutants was isolated that gave a red anthraquinone, subsequently identified as norsolorinic acid (NOR) and representing up to 3–4% of the mycelial dry weight mass. The wild-type high aflatoxin-producing strain yielded a small quantity of this pigment; however, all the NOR mutants synthesized limited amounts of aflatoxin B1 or none at all. Further mutagenesis of NOR mutants resulted in survivors still with reduced aflatoxin elaboration ability. These mutants also gave small quantities of the methoxylated pigment, solorinic acid. The wild-type A. parasiticus NRRL 2999 strain yields 50 times more aflatoxin B1 than NOR pigment, whereas the derived NOR mutants synthesized 100 to 200 times more NOR than aflatoxin B1. The synthesis of NOR in the induced NOR mutants paralleled growth, whereas aflatoxin B1 production occurs typically as growth begins to decline (biphasic synthesis). Such data indicate a possible metabolic block of secondary biosynthesis in NOR mutants since both NOR and aflatoxin B1 are acetate-derived polyketide metabolites.
Nuclear divisions at meiosis in the ascomycetous yeast Wickerhamia fluorescens
Authors: Rooney Lynn , Moens Peter B.
Published: February 2010

In cultures of cells which have been on sporulation medium for 22 h, all stages of meiosis and sporulation occur. In electron microscopy of glutaraldehyde-fixed cells, spindles and spindle-pole bodies are preserved but chromosomes and kinetochores are not apparent. Photographic records of complete serial sections of some 40 asci in different developmental stages show that during the first meiotic division, the nuclear envelope remains intact and the spindle elongates from about 1 μm to 4 μm. Each of the spindle-pole bodies then divides and the bilobed nucleus contains two short spindles (one in each lobe). During the second division the spindles elongate from about 0.5 μm to 3.5 μm while the nuclear envelope remains intact. As a result there is a four-lobed nucleus, either in a chain formation or in a more compact arrangement. The spindle-pole bodies increase in complexity to varying degrees during the second division. One becomes the organizer of a complete ascospore wall while the other three may develop an incomplete wall and eventually these three nuclei degenerate in the cytoplasm of the ascus. It is shown that the nuclear behavior during meiosis parallels that of the yeast Saccharomyces cerevisiae but differs from that reported for Euascomycetes.
The fine structure of ascospore delimitation in the yeast Wickerhamia fluorescens
Authors: Rooney Lynn , Moens Peter B.
Published: February 2010

Photographic records of complete serial sections of asci in different stages of sporulation show that one of the four nuclear lobes produced during meiosis in the ascus of the yeast Wickerhamia fluorescens has a complex spindle-pole body, which is the site from where the presumptive ascospore wall, or prospore wall, develops and eventually surrounds the ascospore nucleus and associated cytoplasm. The three remaining nuclei develop spindle-pole bodies and prospore walls to lesser and varying degrees. With few exceptions, all three degenerate. The outer membrane of the prospore wall forms a fold, or rim, on the outside of the spore. Thickening of the spore wall takes place first in the asymmetric ring, then around the spore body, and finally at the site where the nucleus is associated with the wall. It is shown that ascospore delimitation in W. fluorescens and Saccharomyces cerevisiae are similar to each other, and that it differs from the type observed in a number of Euascomycetes.
The physiology of teichoic acid deficient staphylococci
Authors: Ou Li-Tse , Chatterjee A. N. , Young F. E. , Marquis R. E.
Published: February 2010

Cell walls isolated from a teichoic acid deficient mutant (52A5) of Staphylococcus aureus strain H were found to have lower capacities to bind cations than did walls of the parent strain. Both types of walls had higher binding affinities for Mg2+ and Ca2+ than for K+ and Na+. The reduced number of phosphate groups in 52A5 walls was reflected in a higher apparent pKa of 4.3 for displacement of Mg2+ (or Ca2+) during acid titration with HCl. The comparable pKa value for displacement of bound Mg2+ from parent-strain walls was 3.7. The reduced capacity of 52A5 walls to bind cations was not reflected in any significant increase in sensitivity to the growth inhibitory actions of ethylenediaminetetraacetate, low pH, or high NaCl concentrations. However, the 52A5 strain was somewhat more sensitive to the inhibitory effects of high pH. Also, mutant walls were found to be structurally more compact than walls of the parent strain, presumably because of less extensive electrostatic repulsion within the wall matrix.
Lysosomes and the "toxicity" of Rickettsiales. V. In vivo relationship of peritoneal phagocytes and egg-attenuated C. psittaci 6BC
Authors: Kordová Nonna , Wilt John C. , Poffenroth Linda
Published: February 2010

The investigations reported here follow the lines of our earlier studies and represent an attempt to identify the inhibitory activities of the lysosomes of mononuclear and polymorphonuclear phagocytes (PMN's) in the peritoneal cavity of mice after intraperitoneal infection with an egg-attenuated C. psittaci 6BC strain (avirulent for mice). Presumptive evidence indicates that lysosomes of macrophages are refractory to "nontoxic" chlamydial particles that are initially ingested, while the adsorption to, and (or) uptake of, these agents by PMN's is followed by disintegration of PMN's which causes release of lytic substances from them. Macrophages infected in vivo are nonspecifically "activated" and some of them "transform" after maintenance in vitro into large epitheloid cells containing numerous well-demarcated chlamydial inclusions in the cytoplasm. Except for the inclusions neither damage nor lysosomal acid phosphatase release was detected in these cells. The Chlamydiae-induced inflammatory reaction and the possible persistence of "nontoxic" Chlamydiae in chronic infection are discussed.
Immunofluorescence of peritoneal phagocytes after infection in vivo with egg-attenuated Chlamydia psittaci 6BC
Authors: Kordová Nonna , Martin Caroline , Wilt John C. , Meyer Wally
Published: February 2010

The present studies on the fluorescence of Chlamydiae-infected peritoneal cells have demonstrated considerable variation in the morphology, distribution, and localization of antigen in the phagocytes of the mononuclear series. In addition, diffuse or patchy fluorescence was detected in the cytoplasm of apparently intact polymorphonuclear phagocytes (PMN's). Small lymphocytes "coated" with a thin layer of diffuse fluorescence appeared to be firmly attached to macrophages, which exhibited specific staining. A marked increase of chlamydial antigen was present in peritoneal cells (infected in vivo) after they were kept in vitro. Epitheloid cells were evident in long-term cultures and demonstrated strong specific fluorescence, which was associated with intracellular membranes and enlarged nucleoli; cytoplasmic inclusions stained only faintly. In contrast Giemsa-stain demonstrated classical chlamydial inclusions. The significance of localization and persistence of chlamydial antigens in phagocytes is discussed.
Qualitative assays of ribonuclease produced by plant pathogenic fungi
Authors: Berkenkamp B.
Published: February 2010

The extracellular production of ribonuclease by fungi grown on solid and liquid media was demonstrated by turbidity of remaining RNA, ultraviolet absorption by hydrolytic products, spectral shift of thionine, and fluorescence of acridine orange. The test fungi varied considerably in their ability to produce ribonuclease, but slight activity was detected with all eight fungi tested in liquid media. The results of liquid assays were not in complete agreement, probably because the four tests measured different features of the hydrolysis of RNA. Assays of 15 fungi on solid media were useful only in the qualitative detection of ribonuclease.
The use of ferritin-conjugated antibodies in the study of cell wall components of Candida albicans
Authors: Venezia Richard A. , Lachapelle Rene C.
Published: February 2010

Studies on the antigenic sites of the cell wall of Candida albicans were performed with ferritin-conjugated antisera of rabbits immunized with heat-killed cells in the yeast phase. Whole cells, from yeast and mycelial forms, and preparations of walls from disrupted cells were labeled with ferritin-conjugated antibodies. Ferritin-labeled anti-yeast phase IgG antibodies reacted equally well with the yeast and mycelial forms. The label was uniformly distributed over both the internal and external surfaces of the cell wall. This study demonstrates the continuity of antigenic determinants in the cell wall of both forms of C. albicans.
Chlamydospore-like cells in Candida albicans induced by 5-fluorocytosine
Authors: Lee Wie-Shing
Published: February 2010

Chlamydospore-like cells of Candida albicans were formed as tiny colonies within the inhibition zone when 5-fluorocytosine was applied on inoculated yeast nitrogen agar by disc method.
Production of mesophilic mutants from a psychrophilic Bacillus
Authors: Kim Kyung Jin , Larkin John M.
Published: February 2010

From the psychrophile, Bacillus psychrophilus, 10 mesophilic mutants were obtained. Other than the differences in cardinal temperatures, they were identical with the parent organism, even in ribosomal thermostability.
A bilayer plate technique to detect broad-spectrum antagonism in microorganisms and its application to wood-inhabiting fungi
Authors: Etheridge D. E. , Craig H. M.
Published: February 2010

A simple method is described for measuring antagonistic activity in microorganisms based on the mycelial growth response of up to 10 isolates of the bioassay fungus in a single agar plate. The technique overcomes disadvantages of existing methods by providing quantitative estimates of interstrain variability in the bioassay fungus as well as the antagonist. Application of the method to a wide range of isolates of Ascocoryne sarcoides (Jacq. ex Gray) Groves and Wilson against three species of decay fungi has permitted the rapid detection of broad-spectrum strains of this fungus which would not have been practical by conventional bioassays.
Outer (cell wall) membrane proteins of Pseudomonas aeruginosa
Authors: Stinnett J. D. , Eagon R. G.
Published: February 2010

Cell envelope membranes were isolated from Pseudomonas aeruginosa. These membranes were resolved into cytoplasmic membrane rich and outer (cell wall) membrane rich fractions by discontinuous sucrose density gradient centrifugation. The resolution was based on the separation of enzyme activities and 2-keto-3-deoxyoctonate. Analysis by gel electrophoresis revealed that two of the three major cell envelope protein components were found in the fraction rich in outer (cell wall) membrane. These two protein components were previously shown to occur in a protein–lipopolysaccharide complex in this microorganism.
Demonstration of delayed hypersensitivity to Neisseria meningitidis
Authors: Pribnow James F. , Besemer Diana J. , Hall Joan M. , Vedros Neylan A.
Published: February 2010

Guinea pigs were sensitized to Neisseria meningitidis group A by subcutaneous injection of viable meningococci. The animals were skin-tested with heat-killed N. meningitidis, a cell wall preparation of N. meningitidis, and a soluble somatic antigen prepared from the meningococci. Control skin-test substances included heat-killed Neisseria gonorrhoeae, heat-killed Escherichia coli, purified protein derivative, and Hank's balanced salt solution. Positive 24-h skin reactions, characterized by induration that measured greater than 5 × 5 mm (25 mm2), were produced only by heat-killed meningococci and with the cell wall preparations. The soluble somatic antigen produced only erythema. The meningococci also caused inhibition of migration of macrophages when peritoneal cells from the sensitized guinea pigs were used in the capillary tube MIF test. No inhibition of migration was produced with the control antigens. The delayed hypersensitivity was transferred with viable lymph node cells from the sensitized guinea pigs, but not with dead lymph node cells or with serum. The tests will be used to determine whether rabbits injected intravitreally with N. meningitidis develop delayed hypersensitivity.
External morphology of Azotobacter vinelandii during cyst formation
Authors: Cagle Gerald D. , Pfister R. M. , Vela G. R. , Porter J. J.
Published: February 2010

Conventional transmission electron microscopy (TEM), freeze-etching, and scanning electron microscopy (SEM) were used to study changes in the external morphology of Azotobacter vinelandii ATCC 12837 during cyst formation. The various methods of cell preparation used for SEM drastically affected the morphology of vegetative and early precystic forms, while little change was observed in the external appearance of late precysts and cysts. SEM preparations from which cyst exine was removed before observation appeared morphologically similar to frozen-etched cells which revealed the central body.
Regulation of repressible alkaline phosphatase by organic acids and metal ions in Neurospora crassa
Authors: Hochberg Michael L. , Sargent Malcolm L.
Published: February 2010

Various organic acids used in standing cultures of Neurospora regulate the specific activity of mycelial, repressible alkaline phosphatase. The evidence suggests that the regulatory control occurs primarily through chelation of metal ions which are necessary for the production or stability of the enzyme. Both iron and zinc were needed in the growth medium to produce a maximum enzyme level, while a high copper concentration depressed the enzyme level. Electrophoresis of mycelial extracts on gradient polyacrylamide gels demonstrated that the organic acids and iron do not have these regulatory effects on the repressible or constitutive acid phosphatases of Neurospora.
Cytoplasmic glycogen inclusions in cells of anaerobic gram-negative rumen bacteria
Authors: Cheng K.-J. , Hironaka R. , Roberts D. W. A. , Costerton J. W.
Published: February 2010

Megasphaera elsdenii, an anaerobic rumen bacterium, produced intracellular polysaccharide granules varying in size from 0.05 to 0.15 μm during growth in batch culture. This polysaccharide material was purified and was found to contain D-glucose as the only reducing sugar. The polyglucose polymer was highly opalescent in aqueous solution and formed a strong reddish-brown iodine complex with a maximum absorbance at 493 nm. Its infrared spectrum had characteristic absorption bands at 8.70, 9.25, and 9.75 μm and was identical with that of the glycogen of enteric bacteria and beef liver. When these polysaccharide granules were observed with an electron microscope, they resembled the glycogen granules produced by Arthrobacter globiformis and Escherichia coli. These properties indicate that the polysaccharide was a type of glycogen. The yield of crude glycogen was 16.82% of the dry weight of late log-phase cells (14-h).The lysis of cells of M. elsdenii and other rumen bacteria that store polysaccharide granules inside the cells, in the rumen of cows fed a feed of fine-particle size (344 μm, geometric mean particle size) and high-energy content, may contribute to the high-carbohydrate level and high viscosity of the cell-free rumen fluid of these cows. Cows fed a coarse feed (519 μm, geometric mean particle size) of the same composition have rumens that contain few bacteria with polysaccharide granules. The cell-free rumen fluid of these cows has low viscosity and low-carbohydrate content.