bluuebunny/crossref_metadata_2025 huggingface dataset:
Removal of resin acids from culture media and kraft-mill effluents by yeasts and some other fungi
Authors: Spencer J. F. T. , Sinclair G. D. , Gardner N. R.
Published: April 2010

Epicoccum nigrum, Rhinocladiella mansonii, Rhodotorula minuta, and Trichosporon cutaneum were tested for their ability to remove resin acids from supplemented kraft-mill effluent and from a medium containing yeast extract as sole nitrogen source. Up to 39% of the resin acid content was removed by all four organisms. The mutagenic activity of the resin acid preparation, as measured by the induction of gene conversion in a strain of Saccharomyces cerevisiae, was low or non-existent.
On the natural occurrence of California encephalitis virus and other arboviruses in Alaska
Authors: Ritter Donald G. , Feltz Elmer T.
Published: April 2010

California encephalitis virus (Snowshoe Hare strain) was isolated from these Alaskan sources: varying hare (snowshoe hare), Lepus americanus Erxleben; indicator rabbit, Oryctolagus cuniculus (Linnaeus); varying lemming, Dicrostonyx rubricatus (Richardson); northern red-backed vole, Clethrionomys rutilus (Pallas); mosquitoes, Aëdes spp.; and blackflies, Simulium sp. This virus has been confirmed as enzootic in east-central Alaska. Other arbovirus isolations were Silverwater virus, from hare-ticks, Haemaphysalis leporispalustris (Packard); Great Island virus and a virus of the Sakhalin group from bird ticks, Ixodes signatus Birula, from common murres, Uria aalge (Pontoppidan); and Northway virus, a hitherto undescribed member of the Bunyamwera group from a northern red-backed vole, from indicator rabbits, and from hematophagous Diptera. These findings include new host-records and extensions of the known geographic range of some of the viruses isolated.
Ultrastructure of the cell envelope and septation process in Caryophanon latum as revealed by thin section and freeze-etching techniques
Authors: Trentini W. C. , Gilleland Jr. H. E.
Published: April 2010

With optimal conditions of thin-sectioning and freeze-etching, the cell wall of Caryophanon latum was composed of a thick peptidoglycan layer plus two external wall layers. The freeze-etched appearance of the external surface of the outer layer was smooth and lacked structural detail. The numerous cross septa within a trichome were formed by the symmetrical and concurrent ingrowth of the cytoplasmic membrane and the peptidoglycan layer. The site of septum initiation was identifiable by a dart-shaped ingrowth of the peptidoglycan layer rather than by the presence of a mesosome. However, small simple mesosomes were occasionally seen associated with the developing septum. The peptidoglycan in the septum had thickened to at least double the thickness of the wall peptidoglycan layer by the time of septum completion. The external wall layers did not participate in septum formation but did participate in trichome separation. The separation of the septal peptidoglycan was completed during the early ingrowth of the external wall layers. A unique cross-sectional view of a developing septum closing like an iris diaphragm as seen in a freeze-etched preparation was observed.
Sporulation and enterotoxin production by Clostridium perfringens type A under conditions of controlled pH and temperature
Authors: Labbe Ronald G. , Duncan Charles L.
Published: April 2010

The effect of two environmental factors, pH and temperature, on sporulation and enterotoxin production in Clostridium perfringens type A was determined. A maximum level of enterotoxin was obtained in Duncan and Strong sporulation medium when the pH was not controlled by external addition of NaOH. Slightly lower levels were obtained when the pH was controlled at 7.0. Percentage of sporulation and heat-resistant spore population levels were similar at pH 7.0 and when the pH was not externally controlled. Enterotoxin concentration, percentage of sporulation, and heat-resistant spore levels decreased greatly when the pH was kept at 8.0, 8.5, and 6.0. At pH 5.5 vegetative growth occurred although sporulation and enterotoxin production did not. Levels of heat-resistant spores and enterotoxin were higher at 37C than at 25, 30, or 43C. Enterotoxin formation was not detected at 46C.
Purification of Rickettsia rickettsi by density-gradient zonal centrifugation
Authors: Anacker R. L. , Gerloff R. K. , Thomas L. A. , Mann R. E. , Brown W. R. , Bickel W. D.
Published: April 2010

Rocky Mountain spotted fever rickettsiae, cultivated either in yolk sacs of embryonated chicken eggs or in mouse L cells, were purified by centrifugation through a linear sucrose density gradient in a zonal rotor. Under the conditions of the experiments the rickettsiae banded at a density of about 1.21. Intact organisms with what appeared to be large translucent capsules were found in this band. The degree of purity was high because yolk sac contamination was not detected in rickettsial suspensions derived from embryonated eggs, and little extraneous material was observed by electron microscopy in suspensions obtained from either host. About 4 × 108 rickettsial particles were recovered from each gram of yolk sac and 2 × 1010 particles from each gram of L cells, a 50-fold difference. Each milligram dry weight of purified rickettsiae contained about 1 × 1010 particles.
Incorporation de thymidine tritiée par les mycoplasmes parasites du phloème d'une giroflée. Etude autoradiographique à haute résolution
Authors: Gourret Jean-Pierre , Thomas Daniel , Maillet Pierre-Louis
Published: April 2010

Normal and phyllodial inflorescences of a cultivated wallflower (Cheiranthus (Erysimum) allionii) have been placed in a nutrient solution containing tritiated thymidine, during 24 to 48 h in a controlled temperature chamber. A high resolution autoradiographic study of the phloem in these inflorescences reveals a characteristic labeling of the mycoplasmas abundantly present in the sieve elements of the diseased branches.[Journal translation]
Low-temperature-growing clostridia from marine sediments
Authors: Finne Gunnar , Matches Jack R.
Published: April 2010

Marine sediments inoculated into cooked meat medium were enriched for 5 months at 0–5 °C. Organisms isolated and purified were tested for growth at low temperatures, and those growing only anaerobically at 5 °C and below were retained for further study. The growth–temperature range was determined by growing 18 isolates on a temperature-gradient incubator over a temperature range of 0 to 34 °C. On the bases of minimum, optimum, and maximum growth temperatures, the 18 isolates were separated into obligate and facultative psychrophilic and psychrotrophic clostridia. The DNA was extracted from cells grown at 12 °C and the percentage of G + C for all the isolates fell within the range characteristic of Clostridium species. The volatile alcohols and acids produced on a glucose medium were detected by gas chromatography. Ten of the isolates produced no alcohols and only acetic and butyric acids. One isolate produced butanol and acetic and butyric acids. The remaining seven isolates produced one or two alcohols, ethanol and butanol, and up to six acids. The 18 isolates fell into distinct groups with a close relationship between growth–temperature range and volatile alcoholic and acidic products. Biochemical tests showed that the isolates resembled Clostridium species described in the literature; however, they were not like any known species and were not named.
Genetic mapping and complementation of aromatic mutants in Streptomyces coelicolor A3(2)
Authors: Engel Paulinus P. , Watkins Charles A.
Published: April 2010

Mutation sites in five Aro− strains of Streptomyces coelicolor A3(2) were mapped. None of the mutants use quinate or shikimate. Results from mapping, complementation, and growth response to aromatic amino acids and vitamins indicate that at least three different genes are affected in these five mutants.
Physiology of sporeforming bacteria associated with insects. V. Tricarboxylic acid cycle activity and adenosine triphosphate levels in Bacillus popilliae and Bacillus thuringiensis
Authors: Yousten Allan A. , Hanson R. S. , Bulla Jr. Lee A. , Julian Grant St.
Published: April 2010

Six tricarboxylic acid cycle enzymes were assayed in cell-free extracts of Bacillus popilliae and B. thuringiensis at various times during the early and late stationary phases of growth. In B. popilliae, citrate synthase and isocitric dehydrogenase were present at very low levels at all times. After completion of exponential growth, adenosine triphosphate (ATP) levels in B. popilliae cells fell over 100-fold and the cells failed to sporulate. Supplementation with glucose allowed reestablishment of high ATP levels but did not allow sporulation. Resuspension of postexponential cells of B. popilliae in glucose-supplemented spent broth prepared from a sporogenous strain of B. subtilis did not allow sporulation. This technique had previously been successful in allowing sporulation of tricarboxylic acid cycle mutants of B. subtilis. In contrast, B. thuringiensis tricarboxylic acid cycle enzymes increased in activity after completion of exponential growth, ATP levels remained high, and most cells in the population underwent sporulation.
Biochemical and genetic studies of laboratory purine auxotrophic strains of Micrococcus luteus
Authors: Mohapatra Nirupama , Kloos Wesley E.
Published: April 2010

Purine auxotrophic strains of Micrococcus luteus, obtained from different laboratories, were identified as purE mutants and appear to be blocked in the conversion of 5-amino-imidazole ribonucleotide to 5-amino-4-imidazolecarboxylic acid ribonucleotide.
Plaque formation in Bacillus subtilis, and growth inhibition of Bacillus subtilis and Sarcina sp., induced by Schizophyllum commune
Authors: Parag Y. , Parag Gisia
Published: April 2010

Mutants of the fungus Schizophyllum commune produce a presumed antibiotic inhibiting Sarcina and Bacillus subtilis. The production is controlled by a single gene mutation. Strains of Schizophyllum also induce the appearance of plaque-like lytic areas in B. subtilis, which cannot be attributed to phage. The two phenomena are independent.
In vitro studies of an alkaline phosphatase – cell wall complex from Pseudomonas aeruginosa
Authors: Day D. F. , Ingram J. M.
Published: April 2010

Alkaline phosphatase (APase) of Pseudomonas aeruginosa exists primarily in the periplasmic region of the cell, i.e., between the cytoplasmic membrane and the outer tripartite layer. The enzyme is also found in the culture filtrate or associated with the outer layer of the cell wall. APase forms a complex with released outer cell wall material, and lipopolysaccharide (LPS) is associated with the complex. Since the enzyme was purified to homogeneity, it became desirable to determine whether complex formation with LPS, or the outer cell wall, affected any properties of the purified phosphatase. The ratio of activities of purified APase with p-nitrophenylphosphate and β-glycerolphosphate as substrates is about 4:1. The ratio of activities with enzyme complexed with LPS is about 1:1. The energy of activation of sucrose or magnesium released enzyme is 9500 cal/mol whereas the values for purified enzyme plus LPS, purified enzyme, purified enzyme plus phosphatidylethanolamine (PE), and purified enzyme plus LPS plus PE range from 3400 to 8700 cal/mol. These changes occur in the physiological temperature range, 27 to 39C, of this organism. Sucrose-released enzyme in the presence of substrate is inactivated at 47C whereas pure enzyme plus substrate is affected at 41C. The addition of LPS, PE, or a combination of both increases the temperature of inactivation from 45 to 51C. The results suggest that certain properties of the purified enzyme differ from those of the enzyme released from whole cells by either sucrose or magnesium resuspension. The addition of cell wall components such as LPS and PE to purified APase restores these properties. The evidence suggests that artificial complex formation changes the environment of the enzyme protein such that the environment now resembles that which exists within the whole cell wall.
Cellulase location in Cellvibrio fulvus
Authors: Berg Björn
Published: April 2010

The location of cellulase in C. fulvus depends on the carbon source for growth and the age of the culture. When cells were grown on glucose or cellobiose all CMC-hydrolyzing enzyme was cell-bound but only part of the activity was located on the cell surface. Treatment of cells with EDTA, lysozyme, and detergents and subsequent fractionation experiments showed that cellulase was also located in the periplasm and bound to a membrane fraction.Growth on cellulose gave cell-free cellulase active against CMC. The enzyme was repressed by glucose but formed at a constant differential rate on cellobiose and amylose. This rate was 8–10 times lower than on cellulose and possible reasons for this are discussed.
Loss of primary alkylsulfatase and secondary alkylsulfatases (S-l and S-2) from Pseudomonas C12B: effect of culture conditions, cell-washing procedures, and osmotic shock
Authors: Fitzgerald J. W. , Laslie W. Wayne
Published: April 2010

Secondary alkylsulfatases (S-1 and S-2) were detected in Pseudomonas C12B cultured in minimal media lacking alkylsulfates. The synthesis of these enzymes was not repressed by SO42− and L-cysteine or derepressed by L-methionine. Growth on 4% sodium citrate caused a 98% loss in the secondary alkylsulfatase activity of cells and 9% of this activity was detected in the culture medium. Citrate (20 mM) inhibited the activity of cell extracts (18%) but the inhibition was reversible by dialysis. The primary alkylsulfatase content of cells was not diminished by growth on citrate. The MgCl2 concentration of the medium also influenced the cellular levels of secondary alkylsulfatase. Bacteria grown on MgCl2 (0.05 mM – 40 mM) exhibited progressively increasing activity while the converse distribution was observed for activity present in the medium after growth at each MgCl2 concentration. Both primary and secondary alkylsulfatases were released when cells were either subjected to osmotic shock or treated for cell wall removal. Cells washed with 0.085 M sodium citrate – 10 mM Tris – 20% sucrose released roughly 87% of both enzymes and MgCh (0.04 M) inhibited the release of primary alkylsulfatase by 11% and secondary alkylsulfatase by 50%. It is suggested that citrate chelates divalent cations necessary for the attachment of secondary alkylsulfatase at the cell periphery.
Effect of carbon source during growth on sensitivity of Pseudomonas fluorescens to actinomycin D
Authors: Walker Cynthia A. , Durham Norman N.
Published: April 2010

Sensitivity to actinomycin D (AD) varies in Pseudomonas fluorescens cells grown in glucose or succinate minimal salts medium. Growth is inhibited in succinate minimal medium by much lower concentrations of AD than in glucose minimal medium. Uptake of selected radioactive metabolites is inhibited by AD in cells incubated for 2 h in succinate medium containing AD but glucose-grown cells were not sensitive. EDTA treatment promotes increased sensitivity to AD in succinate-grown cells but does not alter sensitivity in glucose-grown cells. Succinate-grown cells bound 2–3 times as much 3H-AD as glucose-grown cells. Glucose-grown cells had much higher lipopolysaccharide levels in the envelope than succinate-grown cells. It is proposed that the lipopolysaccharide masks the binding sites and, therefore, is responsible for the difference in binding of AD by the glucose- and succinate-grown cells. The availability of the binding sites is also reflected in the sensitivity of the cells to the antibiotic.
Regulation of mannitol-1-phosphate dehydrogenase in Aspergillus nidulans
Authors: Hankinson Oliver , Cove David J.
Published: April 2010

When Aspergillus nidulans is grown with urea as sole nitrogen source it possesses about sixtold higher activity of mannitol-1-phosphate dehydrogenase than when it is grown with both urea and sodium nitrate.
New evidence for an intermediate polymer of glucose in cellulose biosynthesis by Acetobacter xylinum
Authors: Kjosbakken J. , Colvin J. Ross
Published: April 2010

The results of sucrose-density-gradient centrifugation of a cell-free particulate enzyme system from Acetobacter xylinum which was incubated with uridine diphosphoglucose indicate that there is a polymeric intermediate in the biosynthesis of cellulose. This intermediate has the properties of an oligomer of glucose, is normally attached to the heaviest particle of the suspension, but, when released by hydrolysis, is preferentially adsorbed to fragments of preformed cellulose. It may form short segments of microfibrils when precipitated from alkaline solution by ethanol. The presence of this intermediate raises again the question of a primer in cellulose biosynthesis.
Conversion of spheroplast symbiotes in a leafhopper, Helochara communis Fitch (Cicadellidae: Homoptera)
Authors: Chang K. P. , Musgrave A. J.
Published: April 2010

In mycetomes of leafhoppers, Helochara communis, ultrastructural and histochemical studies revealed that spheroplast symbiotes (t-symbiotes) were converted to 'a-symbiotes' (so-called), with apparent loss of DNA—a phenomenon reminiscent of rhizobium–bacteroid conversion in certain legume nodules. Additional t-symbiotes were incorporated into the substance of these 'a-symbiotes.'
Progeny resulting from complementation between mutants of vesicular stomatitis virus
Authors: Cormack D. V. , Sword H. , Holloway A. F.
Published: April 2010

The complementation properties of the virus progeny released from cells mixedly infected with mutants of vesicular stomatitis virus belonging to four different complementation groups have been examined. The group IV mutant, tsW16B, was tested in combinations with three group I mutants (tsW4, tsW28, and tsG11), one group II mutant (tsG22), and one group III mutant (tsW29).Virus stocks were grown from isolated plaques appearing on the cell monolayers used to assay the mixed infection yields and tested, in a second series of mixed infections, for their ability to complement each of the two parents. It was found that the virus harvested from each one of the first series of mixed infections contained mutants of both parental types.
The ecological significance of sinking to planktonic bacteria
Authors: Jassby Alan D.
Published: April 2010

Morphological and density measurements were made on planktonic bacteria from a subalpine lake. The observations were then used to predict in situ sinking rates from certain theoretical considerations. The predicted rates agreed well with observed sinking rates (on the order of 1 mm day−1). A simple analysis showed that sinking terms can be neglected in explaining distributions of unattached bacteria, except perhaps in relation to the presence of "bacterial plates."
Fine structure and distribution of extracellular polymer surrounding selected aerobic bacteria
Authors: Cagle Gerald D.
Published: April 2010

The structure and distribution of extracellular polymer surrounding Bacillus circulans, Diplococcus (Streptococcus) pneumoniae, Streptococcus salivarius, Staphylococcus aureus, Klebsiella pneumoniae, Pseudomonas aeruginosa, Herellea vaginacola (Acinetobacter calcoaceticus), and Agrobacterium tumefaciens were studied by electron microscopy. A modified ruthenium red staining procedure was used to examine the fine structure of capsule and slime. Freeze-etching and critical-point drying were used to examine the quantity of unaltered exocellular material. Comparative data demonstrate that fibrillar extracellular polymer surrounding B. circulans, D. pneumoniae, and K. pneumoniae is capsule (cell wall attached) which is characteristic of the producing organism. Capsular polymer generally appeared fibrillar, although globular polymer consisted of capsular subunits bound to S. salivarius and H. vaginacola. Exocellular slime was present about S. aureus, P. aeruginosa, and A. tumefaciens.
Resistance to streptomycin in a producing strain of Streptomyces griseus
Authors: Cella R. , Vining L. C.
Published: April 2010

Streptomyces griseus S 104 was sensitive to streptomycin during exponential growth in a medium which, in the subsequent stationary phase, supported production of the antibiotic in yields above 200 μg/ml. When antibiotic production began cultures developed a tolerance toward their lethal metabolite. This was not due to an increase in pH associated with antibiotic production, since pH effects on streptomycin sensitivity in S. griseus were in the reverse direction. However, the degree of tolerance was directly related to the amount of cell material present. Streptomycin production caused no change in the proportion of resistant variants in the population, nor did it cause the severe inhibition of protein synthesis observed in non-producing cultures exposed to the antibiotic. The lack of an effect on protein synthesis is attributed to the absence of streptomycin within the cytoplasm since soluble extracts from mycelium harvested in the production phase were inactive when bioassayed immediately after cell disruption. However, they developed antibacterial activity rapidly when heated, and more slowly when incubated at 25 °C. The addition of phosphatase inhibitors during incubation prevented the appearance of antibiotic activity, and it was concluded that a small amount of streptomycin phosphate is present in the mycelium during antibiotic production. Differences in (14C) streptomycin uptake suggested that the mycelium was appreciably less permeable to the antibiotic in the production phase than during exponential growth. However, a small amount was taken up and much of it was in the soluble fraction of disrupted cells. Bioassays showed that this 14C-labeled antibiotic within the cells had been partially inactivated, suggesting that conversion of streptomycin to an inactive derivative is involved in the mechanism which protects the organism from its metabolite.
An experimentally pathogenic Bacillus species. II. The pathogenicity of the organism for mice
Authors: Stamper Jr. Hugh B. , Chorpenning Frank W.
Published: April 2010

The pathogenic effects produced in mice by intraperitoneal (i.p.) injection of a Bacillus species (OSU 372) are presented. This organism belongs to group 3 of the genus, and members of this group have not heretofore been shown to be pathogenic for mice even under experimental conditions. However, this organism is capable of producing a fatal involvement in doses which are not considered to be overwhelming. The mean lethal dose (LD50) of the organism for 20–25 g mice by the i.p. route is about 1 × 108 bacteria/mouse. A rapid drop in body temperature along with severe dehydration were noted in infected animals, and hematologic studies indicated that leukopenia and hemoconcentration also occurred. Although a transient septicemia developed, the bacteria could not be recovered from the tissues of fatally infected mice after a certain point in time. Results presented indicate that the animals died of hypovolemic shock. A possible parallel with human bacillary infection is drawn.
Participation of exogenous thymine and thymidine in deoxyribonucleic acid synthesis in Lactobacillus acidophilus
Authors: Sawula R. V. , Zamenhof S. , Zamenhof P. J.
Published: April 2010

The degree of participation (DP) of exogenous thymidine and thymine in overall DNA synthesis was studied in Lactobacillus acidophilus R-26. The DP of thymidine remains constant under a variety of conditions (except at low thymidine concentrations, when the DP is influenced by deoxyribonucleosides and folic acid). A 5-bromodeoxyuridine-resistant mutant was isolated, which displayed cross-resistance to 5-bromouracil and a significantly lower DP of thymidine than the parental strain. Thymine was poorly incorporated in the parental strain even in the presence of deoxyribosides. The results of this investigation would be compatible with the possibility of an alternative pathway for thymidylate synthesis other than the known thymidylate synthase pathway.
Fungal fimbriae. I. Structure, origin, and synthesis
Authors: Poon N. H. , Day A. W.
Published: April 2010

Fine hair-like appendages on the cell walls of the anther smut Ustilago violacea are described. These hairs are termed fimbriae because of their close similarity to the fimbriae (pili) found on certain Gram-negative bacteria. Cells of U. violacea may carry more than 200 fimbriae varying in length from about 0.5 μm to over 10 μm, and having a diameter of about 60–70 Å. Some fimbriae produce knobs similar to those found on bacterial sex fimbriae. Log-phase cells are the most densely fimbriated, while stationary phase cells are devoid of fimbriae. The cells can be de-fimbriated by sonication, high-speed agitation, or centrifugation through a 40% sucrose solution. The fimbriae can regenerate in these defimbriated cells in about 1 h. This regeneration is inhibited by both cycloheximide and rifampin, but not by chloramphenicol and therefore appears to depend on de novo protein synthesis on cytoplasmic ribosomes. Similar long fimbriae are found on U. maydis and Leucosporidium (Candida) scottii. Short fimbriae, about 0.5 μm long, were found on all the other species of yeast-like fungi examined (Rhodotorula, Saccharomyces, Schizosaccharomyces, Hansenula, Lipomyces, Nadsonia, and Torulopsis spp.).
Differential isolation of Pythium species from soil by means of selective media, temperature, and pH
Authors: Lumsden R. D. , Ayers W. A. , Dow R. L.
Published: April 2010

Pythium aphanidermatum, with an optimum temperature for growth at 35C, grew well and was readily isolated from soil on pimaricin–vancomycin medium (MPVM) when incubated for24 h at 38–40C. The pH of the medium affected recovery; maximum numbers developed above pH 6.0. Other Pythium spp. were recovered on MPVM at 20–25C, but were excluded by incubation at 38–40C. These Pythium spp. included P. ultimum, P. paroecandrum, P. irregulare, P. mamillatum, and an unidentified Pythium sp. These species grew well and were readily isolated from soil on gallic acid medium (GAM) when incubated for 24–48 h at 20C. P. aphanidermatum and P. myriotylum grew from mycelium on GAM, but their oospores did not germinate nor could they be isolated from soil on this medium. P. myriotylum grew well on MPVM, but was only rarely isolated, even from soils with known high potential for disease caused by P. myriotylum. Propagules of Pythium were enumerated by a plate-dilution frequency method or by a smear-plate method in serial dilutions of soil in 0.3% water agar. This differential isolation method is valuable for studies on the ecology, survival, and inoculum potential in soils with mixed populations of P. aphanidermatum and other Pythium spp.
Antibody production in milk serum after antigen instillation of the goat mammary gland. IX. Sham infection studies with Neisseria meningitidis L.C.D.C. 608B
Authors: Pasieka Arthur E. , Calver G. , Kenny C. P. , Perusse C. , Guerin L. F. , Mitchell Chas. A.
Published: April 2010

Specific immune globulins have been prepared in goat milk in response to the intramammary gland instillation of Neisseria meningitidis 608, serogroup B strain. Isolation, purification, and characterization of the goat whey by gel filtration, electrophoresis, and analytical ultracentrifugation demonstrated that the active immune component resided in the IgA class of globulins, specifically 9.2-S IgA. The potential of the lactating mammary gland as a "biological factory" for the large-scale production of diagnostic antiserum to killed bacterial whole cell antigen is described.
Evidence for the existence of endotoxic activity in three strains of Moraxella
Authors: Davis Richard H. , Palazzolo Arlene M.
Published: April 2010

The phenol extraction technique was used to obtain material with endotoxic activity from three strains of Moraxella. This material was subjected to partial purification. Biological activity was determined by inoculation of the extracts into the skin of rabbits, and noting the resultant skin reactions. Although containing some cellular contaminants such as nucleic acid from the extraction procedure, the endotoxin preparations showed biological activity in the microgram range. Killed but unextracted cells also elicited skin reactions when injected intradermally into the rabbit.A partial analysis of the biochemical components of the endotoxin revealed that these three strains contain endotoxin whose composition is similar in several respects to that of the endotoxins of the neisseriae and some of the enteric bacteria.
Two modifications making membrane filtration more economical
Authors: Maier Siegfried
Published: April 2010

Two economical membrane filtration techniques are described: (1) vacuum filtration through a single funnel into several sterile containers and (2) pressure filtration using an inexpensive combination of pressure source, vessel, and valve.
A new method for the isolation of methionyl transfer RNA synthetase mutants from Escherichia coli
Authors: Armstrong John B. , Fairfield John A.
Published: April 2010

Six methionine auxotrophs were isolated from an E. coli K-12 strain which required up to 100 times as much methionine for growth as a conventional auxotroph. In these mutants, the methionyl-tRNA synthetase had an increased Km for methionine. The Km value for the mutants ranged from 0.48 to 1.63 mM, compared to 0.078 mM for the wild type. The Km (methionine) for S-adenosyl methionine synthetase was not altered.
Immunofluorescence of peritoneal phagocytes after infection of mice with L-cell-attenuated Chlamydia psittaci 6BC
Authors: Kordová Nonna , Wilt John C. , Shewchuk Eleanor , Meyer Wally
Published: April 2010

Large amounts of particulate antigen of Chlamydia psittaci 6BC attenuated by growth in L cells were phagocytized by peritoneal mononuclear phagocytes during the 1st h after intraperitoneal inoculation. The phagocytes subsequently destroyed the immunofluorescent (IF) properties of the chlamydial antigens. It is suggested that the early damage of phagocytes by lysosomal enzymes activation induced by chlamydiae contributed to the relatively early disappearance of IF antigens from the peritoneal fluids.
A numerical taxonomic study of the strains of three types of Corynebacterium renale
Authors: Yanagawa R.
Published: April 2010

Numerical analysis has been carried out on 100 features of 55 strains of Corynebacterium renale. Three phena were formed, which respectively corresponded to three immunological types of C. renale.
Distinction des tryptophanases de cinq espèces d'Entérobactériaceae par les groupements sulfhydryles
Authors: Simard C. , Mardini A. , Bordeleau L. M.
Published: April 2010

We have studied the sulfhydryl groups (—SH) on the tryptophanases (TPases) from Escherichia coli B. and E. aurescens, Shigella alkalescens, and Proteus vulgaris and P. morganii. The coli group and the P. morganii apo TPases have 20 —SH groups per mole of enzyme, whereas P. vulgaris apo TPase has 16. In coli group TPases, there are 16 —SH groups on the mole surface and they are all implicated in the activity and the enzyme–substrate bond. Proteus morganii TPase has 8 surface —SH groups, 4 of which are implicated in the activity; the remaining 12 —S H groups are located inside the mole and take part in the activity and the enzyme—substrate bond. Proteus vulgaris TPase has 4 surface —SH groups which are constitutive of the enzyme structure, whereas the 12 remaining —SH groups are located inside the mole and take part in the activity and the enzyme–substrate bond. It is concluded that Proteus TPases are molecules which have inverted quaternary structure in comparison to those of the coli group. The studied TPases have four subunits, each of them is constituted of one polypeptidic chain having a molecular weight of 55 000. [Journal translation]
Aerobic adaptation in yeast. IV. Alterations in enzyme synthesis during anaerobic–aerobic transitions in exponentially growing cultures
Authors: Ball A. J. S. , Bruver Rita M. , Tustanoff E. R.
Published: April 2010

As a corollary to the metabolite data obtained from yeast cultures undergoing an exponential anaerobic–aerobic phase transition, levels of various glycolytic and citric acid cycle enzyme activities have been monitored in these cells. The relation of the changes in these enzyme activities in cells grown on either glucose or galactose is discussed in light of different metabolic postures these cells demonstrate as a result of their transitions.A general discussion is presented which compares the results obtained in this series of papers from both step-down and exponential transfer experiments and relates these data to control of mitochondriogenesis in yeast.
The development and structure of thick-walled, multicellular, aerial spores in Diheterospora chlamydosporia (=Verticillium chlamydosporium)
Authors: Campbell W. P. , Griffiths D. A.
Published: April 2010

The aerial, thick-walled spores of Diheterospora chlamydosporia arose as terminal swellings on erect hyphae. Repeated septation of the continuously swelling spore resulted in a multicellular structure. Immediately after the onset of septation secondary wall material was laid down between the two-layered primary wall and the plasmalemma. The presence of secondary wall material indicates that the multicellular spore is a dictyochlamydospore and not an aleuriospore. The relationship between chlamydospores and aleuriospores in other fungi is discussed.
Enzymes of ammonia assimilation in Rhizobium leguminosarum bacteroids
Authors: Kurz W. G. W. , Rokosh D. A. , Larue T. A.
Published: April 2010

The activities of the following enzymes were studied in connection with dinitrogen fixation in pea bacteroids: glutamine synthetase (L-glutamate:ammonia ligase (ADP-forming)) (EC 6.3.1.2) (GS); glutamate dehydrogenase (NADP+) (L-glutamate:NADP+ oxidoreductase (deaminating)) (EC 1.4.1.4) (GDH); glutamate synthase (L-glutamine:2-oxoglutarate aminotransferase (NADPH-oxidizing)) (EC 2.6.1.53) (GOGAT). GS activity was high throughout the growth of the plant and GOGAT activity was always low. It is unlikely that GDH or the GS–GOGAT pathway can account for the incorporation of ammonia from dinitrogen fixation in the pea bacteroid.
Comparison of several methods for the isolation of salmonellae from egg products
Authors: Schothorst M. van , Leusden F. M. van
Published: April 2010

Lactose broth and buffered peptone water proved to be equally effective as preenrichment media in the isolation of salmonellae from egg products. With tetrathionate bile brilliant green broth, incubated at 43 °C as enrichment medium, more samples were found to be positive than with selenite cystine broth incubated at 37 °C or 43 °C and selenite brilliant green broth incubated at 37 °C. As selective agar, brilliant green agar proved to be more reliable than bismuth sulfite agar. These results indicate that the ISO method for the isolation of salmonellae from meat and meat products can be successfully used for the examination of egg products.
Fine structure of sporogenesis and septum formation in Micromonospora globosa Kriss and M. fusca Jensen
Authors: Stevens Richard T.
Published: April 2010

Sporogenesis in two species of Micromonospora, M. globosa and M. fusca (Actinomycetes) was quite similar. As in fungi, spore formation began as a blowing-out of a hyphal tip with the subsequent centripetal invagination of the plasma membrane. Septal wall material was deposited in a typical three-layered pattern, i.e., two electron-opaque layers separated by an electron-transparent layer. A second electron-opaque wall layer was later formed within the spore and finally a third, less electron-opaque wall was produced. Spore dehiscence was facilitated by the fragmentation of the first-formed wall surrounding the spore. Sporogenesis in Micromonospora is blastic in nature producing terminal, thick-walled spores.In M. fusca, a sporulation process was observed which closely resembled sporangial formation. The process appeared similar to that described for the genus Actinoplanes. Swollen, multiseptate structures were also present.Also in M. fusca, perforate septa with flared pore margins were observed. These septa were similar in appearance to the dolipore septa of Basidiomycetes although they lack a parenthesome and pore plug.Although an extensive membrane system (mesosome) was associated with the finishing septum, its function in the process of septum formation was not determined.
A selective medium for the isolation of Saprolegnia spp. from freshwater
Authors: Ho H. H.
Published: April 2010

A selective medium was developed for the isolation of Saprolegnia spp. from freshwater.
A modifier mutation affecting utilization of mannitol in pneumococcus
Authors: Rotheim Minna B. , Hotchkiss Rollin D.
Published: April 2010

The altered growth of a pneumococcal mutant containing marker M, which confers ability to utilize mannitol, and a modifier gene is reported. The modifier gene is closely linked to the M gene and imposes a requirement for growth in 0.4% glucose before growth in mannitol medium. The tentative position of the M gene of pneumococcus is ery-r str-r M sul-rd.
Biochemical changes during sporulation of Bacillus stearothermophilus
Authors: Orlowski Michael
Published: April 2010

The process of sporulation was studied in Bacillus stearothermophilus. A medium is described that supports good growth and sporulation of the organism. In this medium, which contains glucose, salts, and amino acids, acetate starts to accumulate before any of the glucose is catabolized. Enzymes of the tricarboxylic acid cycle are present at all times during growth and sporulation and are found in dormant spores. As the glucose in the culture is consumed, acetate rapidly increases and the pH of the medium drops. The acetate rapidly disappears during sporulation and the pH rises. Dipicolinic acid appears during sporulation and several key-enzyme activities fluctuate in a characteristic pattern.
Purification and properties of a nuclear polyhedrosis virus from Choristoneura fumiferana
Authors: Arif Basil M. , Brown Keith W.
Published: April 2010

The polyhedral inclusion bodies of a nuclear polyhedrosis virus from the spruce budworm Choristoneura fumiferana were purified by fluorocarbon treatment, sucrose columns, sucrose density gradients, and equilibrium centrifugation. The preparation yields a single and homogeneous band in potassium tartrate gradients at a density of 1.193 g/ml. The virions were released from the polyhedra by alkali treatment and purified by either rate zonal or equilibrium centrifugation in sucrose gradients. The purified virions, which band at a density of 1.265–1.300 g/ml in sucrose, were infectious to the spruce budworm larvae and their mean LD50 was 1.09 ± 0.1 μg of virus. However, viral nucleocapsids, released by a nonionic detergent, Nonidet P-40, had a density of 1.315 g/ml and were noninfectious by either per os inoculation or intrahemocoelic injection.
Role of pectic and cellulolytic enzymes in the invasion of the soybean by Rhizobium japonicum
Authors: Hunter William J. , Elkan Gerald H.
Published: April 2010

Past workers have suggested pectic enzyme involvement in the invasion of legumes by Rhizobium. However, no role for pectic acid, pectin, or methyl cellulose depolymerase enzymes in the invasion of R. japonicum was suggested by the current study. Seedling inoculation with infective bacteria did not result in increased enzyme activity. Rhizobium japonicum cell-free culture extracts and 3-indoleacetic acid did not affect the activation, induction, or binding of these enzymes.
Mutant atténué nitrosoguanidine-induit dans la gangrène gazeuse à Clostridium perfringens type A
Authors: Lapointe Jean-Rock , Fredette Victorien
Published: April 2010

A fully virulent classical type A strain of Clostridium perfringens was treated during its logarithmic growth phase with 100 μg/ml of N-méthyl-N′-nitro-N-nitrosoguanidine, the bacteria being exposed to the mutagen for 30 min at 37 °C in a phosphate buffer adjusted to pH 6.2; after treatment the suspension was streaked on sheep blood agar plates, and colonies that showed an alteration in the theta-hemolysis pattern were selected for isolation. The virulence of two mutants, thus altered in their thêta-hemolysis, was studied. One, designated LNG 5, was still capable of killing most of the inoculated guinea pigs in less than 24 h with all the clinical, macroscopic, and bacteriological signs of gas gangrene; however, histological sections showed that tissue damage was not as marked as with the wild strain. On the contrary, the second mutant, labelled LNG 11, was completely avirulent as far as gas gangrene was concerned; indeed, the injection of fluid cultures containing 1 × 108-109/ml viable bacteria, was not followed by any clinical, bacteriological, or histological signs of gas gangrene. However, strain LNG 11 did give rise to a firm swelling of the inoculated thigh with a corresponding acute inflammatory response of the connective tissue, although the muscle fiber was unaltered. Eventually, this local reaction was followed by necrosis of the skin accompanied by an acute or subacute inflammation with fibroblastic proliferation. These superficial lesions healed spontaneously. They could not be reproduced with crude filtrate alone or with washed bacilli. Strain LNG 11 was therefore considered to be solely an attenuated strain since, although avirulent as far as gas gangrene is concerned, it is still capable of producing low levels of toxic material. This appears to be the first time that such a strain of C. perfringens type A has been obtained by nitrosoguanidine treatment.
Soil bacteriostasis: inhibition of spore germination and microcolony development in agar discs incubated on nonsterile soils
Authors: Davis Robert D.
Published: April 2010

An agar-disc method showed that bacterial spores were subject to a bacteriostatic effect exerted by soil. Soil either inhibited spore germination or reduced microcolony development of the six Bacillus strains tested. Bacteriostasis was relieved by the addition of nutrients to soil-exposed discs after they had been removed from the soil.
Characterization of the factors responsible for death of fish infected with Vibrio anguillarum
Authors: Umbreit Thomas H. , Tripp M. R.
Published: April 2010

Vibrio anguillarum produces substances toxic for goldfish (Crassius auretus) that are released from living bacteria and associated with heat-killed bacteria. Heating (100 °C) enhances the potency of the extracellular toxin.
Induction of avirulent variants in Erwinia stewartii by incubation at supraoptimal temperatures
Authors: Garibaldi A. , Gibbins L. N.
Published: April 2010

High temperatures (37 °C) induced non-pigmented, and (or) small colony variants in some Erwinia stewartii strains. The former differed from the parent strain serologically and in having lost virulence to Zea mays. The small colony variants retained phytopathogenicity.
Cytoplasmic inclusions in canine cells infected with infectious canine laryngotracheitis (ICL) adenovirus
Authors: Shahrabadi M. S. , Yamamoto T.
Published: April 2010

Spherical dark inclusions were observed in both the cytoplasm and nuclei of infectious canine laryngotracheitis (ICL) adenovirus infected MDCK (Madin–Darby Canine Kidney) cells. The distribution of these inclusions in the cells appeared to indicate that they were formed in both the cytoplasm and in the nucleus at about the same time and there did not appear to be movement of these inclusions between the cytoplasm and the nucleus during the early stages of infection.Morphological appearance, 3H-leucine autoradiography, and immunoferritin labelling showed that the cytoplasmic inclusions were similar in nature to the dark nuclear inclusions, and contained the adenovirus hexon antigen, but not the penton base and fiber antigens.
Nitrification on a coral reef
Authors: Webb Kenneth L. , Wiebe W. J.
Published: April 2010

We report that the algal pavement just behind the reef crest at Enewetak Atoll produces nitrate at measurable rates. In situ and in vitro incubations with N-Serve® indicate that the autotrophic pathway involving two separate organisms is effective in this oxidation of ammonia to nitrate. Significant nitrification is indicated throughout the reef environment; Nitrobacter agilis has specifically been identified as at least one of the organisms responsible for the terminal oxidation of nitrite to nitrate.
Evidence for a relationship between chloroquine and complement from studies with lymphocyte mitogens: possible implications for the mechanism of action of chloroquine in disease
Authors: Forsdyke D. R.
Published: April 2010

Chloroquine increases the inhibition of cultured lymphocytes by high concentrations of phytohemagglutinin (PHA) or concanavalin A (Con A). The inhibition is also increased by complement. Thus chloroquine and complement have similar effects. Time-course studies show that chloroquine increases the rate of onset of the complement-dependent inhibition. In serum preheated to inactivate complement, chloroquine can partially simulate the effect of complement. It is suggested that at certain stages in malaria or autoimmune disease the rate of clearance of parasitized erythrocytes or autoreactive lymphocytes is limited by the concentration of complement. Under these conditions a drug such as chloroquine, which could enhance or simulate the action of complement, might be of therapeutic value.
Fractionation of sulfur isotopes by continuous cultures of Desulfovibrio desulfuricans
Authors: Chambers Lyn A. , Trudinger Philip A. , Smith John W. , Burns Maurice S.
Published: April 2010

Sulfur isotope effects observed in lactate-limited continuous cultures of Desulfovibrio desulfuricans were, in general, similar to those reported for sulfate reduction by washed cells and batch cultures. There was a trend towards higher fractionation at low growth rates.
Effect on microorganisms of volatile compounds released from germinating seeds
Authors: Schenck S. , Stotzky G.
Published: April 2010

Volatile compounds evolved from germinating seeds of slash pine, bean, cabbage, corn, cucumber, and pea were evaluated for their ability to support growth of microorganisms in liquid mineral salts media lacking a carbon source. Growth of eight bacteria was measured turbidimetrically and of six fungi as dry weight of mycelium.Volatiles caused increased growth of Pseudomonas fluorescens, Bacillus cereus, Erwinia carotovora, Agrobacterium tumefaciens, A. radiobacter, Rhizobium japonicum, Mucor mucedo, Fusarium oxysporum f. conglutinans, Trichoderma viride, and Penicillium vermiculatum but not of Sarcina lutea, Serratia marcescens, Chaetomium globosum, or Schizophyllum commune. Spores of Trichoderma viride showed higher germination in the presence of volatiles.Effects on growth were apparent only during the first 3 or 4 days after planting the seeds. Killed or dried seeds had no effect. The volatiles did not support microbial growth in the absence of nitrogen nor did they supply growth factors. Passing volatiles through KMnO4 or hydrazone reduced growth of the bacteria, indicating that oxidizable organic compounds, primarily aldehydes, were the active components. The volatiles were not absorbed by sterile soil, clay minerals, or water, but they were absorbed by non-sterile soil and activated charcoal.
Exopolysaccharide depolymerases induced by Rhizobium bacteriophages
Authors: Barnet Yvonne M. , Humphrey Beverley
Published: April 2010

Enzymes induced by two Rhizobium trifolii bacteriophages caused depolymerization of exopolysaccharides from most R. trifolii and R. leguminosarum strains tested, but did not, in general, attack the exopolysaccharides of R. meliloti, the slow-growing rhizobia, or Agrobacterium. Ca2+ and (or) Mg2+ were required for enzyme activity. In all strains tested, depolymerization of exopolysaccharide occurred when there was successful phage infection, but depolymerization also occurred with exopolysaccharides from nonsusceptible strains.