bluuebunny/crossref_metadata_2025 huggingface dataset:
The physiology of conidial formation in submerged cultures of Claviceps purpurea (Fr.) Tul producing alkaloids
Authors: Řeháček Z. , Kozová J. , Sajdl P. , Voříšek J.
Published: April 2010

Conidial formation in C. purpurea is correlated with a rising ATP utilization, an almost constant rate of protein synthesis, a constant level of intracellular orthophosphate, an accumulation of mycelial lipids, and an increase in the activities of citrate synthase, isocitrate lyase, malate synthase, and intra- and extra-cellular proteinases. In the culture, stringent control of tryptophan biosynthesis is absent. Conidial formation is stimulated by MnCl2 (5.10−4 M) and suppressed by ergotamine (5.10−4 M), ergometrine (5.10−4 M), and glycerol (5.10−3 M), respectively. Ergotamine also lowers the activity of leucineaminopeptidase from the fungus. Alkaloids are synthesized only after conidial formation and the growing stage. In cultures treated with conidiation inhibitors (ergotamine and (or) glycerol), the alkaloid yield is enhanced. It is hypothesized that the concentration of intracellular tryptophan which accumulates during aging is lowered by conversion to alkaloids which are themselves capable of positive feedback which enhances further loss of tryptophan.
Fine structure of selected species of the genus Thiobacillus as revealed by chemical fixation and freeze-etching
Authors: Holt Stanley C. , Shively J. M. , Greenawalt J. W.
Published: April 2010

An electron-microscopic examination of selected species of the genus Thiobacillus was undertaken using the techniques of chemical fixation and freeze-etching. The architecture of the cells was typical of gram-negative bacteria. The multilayered cell envelope was revealed as a complex of smooth, rough, and particle-studded membranes. The particles which covered the outer plasma membrane (convex surface) appeared to contain a differentiated region which might permit a channeling between the exterior and interior of the cell. Inclusion bodies, including paracrystalline arrays, carboxysomes, and granules were present.
Etude ultrastructurale et cytochimique de la conidiogénèse chez Beauveria bassiana (Bals.) Vuill.
Authors: Reisinger O. , Olàh G. M.
Published: April 2010

The ultrastructural and cytochemical aspects of conidiation in Beauveria bassiana (Bals.) Vuill. were studied to elucidate the mechanism of primordium initiation, and to show, by cytochemical analysis, the constituents of conidial walls in terms of polysaccharides and proteins. During the stage of asexual reproduction in this fungus, studies were conducted to localize and quantitate compounds in correlation with data on ultrastructural composition. Therefore we have examined the mother cell forming spores, the conidiation, the structure maturation, and the release of conidiation.[Journal translation]
Serological relationships between Fomes fraxinophilus and F. ellisianus
Authors: Madhosingh C. , Ginns J.
Published: April 2010

The speciation of Fomes fraxinophilus (Peck) Cooke and F. ellisianus Anderson, two morphologically similar organisms, is contentious.Immunochemical data obtained from double-diffusion experiments reflect a close serological relatedness between the cell components in the mycelial extracts of both organisms. Further, a specific precipitin band distinguishes both isolates and supports the proposals for separate species.
Preservation of the sheath of a blue-green alga, Anabaena flos-aquae A-37
Authors: Wang Augustine W. , Tischer R. G.
Published: April 2010

The preservation of the sheath of Anabaena flos-aquae A-37 was achieved when the growing culture was pretreated with a low concentration of glutaraldehyde and fixed using the standard Kellenberger method. The thin sections were stained with an aqueous solution of uranyl acetate at an elevated temperature. The sheath of A. flos-aquae A-37 consisted of fibrous structures and measured about 1.0–2.0 nm in diameter. The fibers were parallel with one another and to the cell surface. The method used eliminated the use of organic dyes and provided an excellent visualization of the sheath and the internal organization.
Pathogenic and immunological properties of culture filtrates of Pseudomonas aeruginosa
Authors: Taubchi K. , Sato H. , Diena B. B.
Published: April 2010

We have investigated the protective capacity and cytotoxicity of filtrates (CF), dialysates (DL), and dialyzed filtrates (DCF) from two highly virulent and two moderately virulent strains of Pseudomonas aeruginosa. Most of the protective ability of the CF was found in the DCF, while the low molecular weight material in the DL was responsible for most of the cytotoxicity of CF. This suggests the possible purification of our culture filtrates (CF) by eliminating the low molecular weight dialyzable material. There was a significant difference in the amount of protein in the DL from the highly virulent strains as compared with DL from strains of lesser virulence. CF and DCF but not DL reacted in an agar gel system against homologous and heterologous CF antisera.
Hexagonal inclusions in an ergosterol-free mutant of Neurospora crassa
Authors: Armentrout V. N. , Maxwell D. P.
Published: April 2010

Refractive hexagonal inclusions in hyphae of wild-type Neurospora crassa were compared with those in two mutants deficient in or lacking ergosterol. The mutants contained more inclusions than the wild type and there were no discernible morphological differences among inclusions of the three strains. It is concluded that these inclusions do not consist of ergosterol as previously reported.
Differential sulfate uptake by two species of bacteria under light or dark incubation conditions
Authors: Monheimer Richard H.
Published: April 2010

Sulfur-35 was used as an isotope tracer to study the uptake of sulfate by Corynebacterium striatum, Pseudomonas fluorescens, and Serratia marcescens in a medium free from organic sulfur. In two different experiments, P. fluorescens and S. marcescens were found to take up sulfate faster when incubated in the dark than in the light. This differential sulfate uptake was not observed for C. striatum. Some of the implications of these results are discussed.
Isolation of a bacterial degrader of the herbicide bromoxynil from a Saskatchewan soil
Authors: Cullimore D. R. , Kohout M.
Published: April 2010

The microbiological degradation of the herbicide bromoxynil was studied under both in vivo and in vitro conditions. A method of enumerating the number of degraders in soil was demonstrated to contain at least 104 degrader cells per gram soil at field capacity. An unidentified bacterial degrader was isolated from the soil and shown to be capable of degrading bromoxynil in vitro and in vivo. An algal bioassay system was used to monitor the degradation of bromoxynil in the in vivo experiments.
Estimation of Thiobacillus ferrooxidans concentrations
Authors: Gormely L. S. , Duncan D. W.
Published: April 2010

A method is presented for estimating Thiobacillus ferrooxidans populations as bacterial nitrogen in systems where inorganic nitrogen may precipitate as ammoniojarosite. The bacterial nitrogen is estimated as the difference between the total nitrogen determined by Kjeldahl digestion – caustic distillation and the inorganic nitrogen determined by caustic distillation. Using this method, the proportion of the bacterial population attached to solids during continuous culture leaching of a zinc sulfide concentrate has been found to be 65%.
Immunofluorescence as a method for the detection of Escherichia coli in water
Authors: Pugsley A. P. , Evison Lilian M.
Published: April 2010

The sensitivity and specificity of a pooled E. coli conjugate specific for enteropathogenic E. coli types, and of a conjugate specific for E. coli O groups frequently associated with urinary tract infections was studied. This demonstrated that FA tests using these conjugates were not suitable for the detection of E. coli in routine water examination. The highest overall rate of positive FA reactions with E. coli strains isolated from water was 38.4%. This figure was considered to be well below that desirable to enable the FA tests to be used as an alternative to conventional cultural methods for the detection of E. coli.
Cell envelope analysis of Coxiella Burneti phase I and phase II
Authors: Jerrells T. R. , Hinrichs David J. , Mallavia L. P.
Published: April 2010

Cell envelopes of Coxiella burneti, Nine Mile, phase I and phase II were examined by electron microscopy and analyzed chemically in an attempt to characterize the phase phenomenon noted in this organism. Electron microscopy of intact organisms as well as cell envelope fractions revealed a morphology similar to many gram-negative bacteria and other rickettsiae. Morphological studies revealed no differences between C. burneti in phase I or II. Chemical analyses revealed a basic composition similar to that reported for members of the genus Rickettsia and many gram-negative bacteria. Cell envelopes of both phase types of this organism (I and II) contained similar amounts of extractable lipid, similar amino acid composition, and the amino sugars glucosamine and muramic acid. Diaminopimelic acid (DAP) was demonstrated in the cell envelope of both phase types. Coxiella burneti phase I differed from the phase II form in carbohydrate composition as well as protein and carbohydrate concentration. Glucuronic acid, glucose, and galactose were found in C. burneti phase I envelopes, whereas only glucose and galactose were present in phase II envelopes.
The interface between the powdery mildew haustorium and the cytoplasm of the susceptible barley epidermal cell
Authors: McKeen W. E.
Published: April 2010

The host–parasite interface separating the haustorium of Erysiphe graminis and the cytoplasm of the barley epidermal cell is an invaginated portion of the host plasmalemma which becomes thicker, more osmophilic, highly invaginated toward the haustorium, and which loses its transparent central stratum. This extrahaustorial membrane is always 1–4 μm distant from the haustorial wall and at first is covered with a thin layer of normal cytoplasm. Later, the host cytoplasm greatly increases in volume, becomes much less dense, and organelles become less confined.
Directed mutation in Streptomyces lipmanii
Authors: Godfrey Otis W.
Published: April 2010

Streptomyces lipmanii produces two β-lactam antibiotics, penicillin N and 7-(5-carboxyvaleramido)-7-methoxycephalosporanic acid. A method has been developed whereby mutation can be directed toward preselected markers, including some affecting antibiotic production. DNA synthesis was synchronized by amino acid starvation of a leucine auxotroph (LA 473). Double-isotope techniques using [14C]- and [3H]-thymidine provided a means of monitoring DNA synthesis. Aliquots of the synchronized culture were treated with N-methyl-N′-nitro-N-nitrosoguanidine (NTG) and plated on selective media. Mutation frequencies for each marker varied as much as 100-fold. The data were consistent with the hypothesis that NTG preferentially mutates the replicating region of DNA.
Enumeration of selected bacterial populations in a high mountain watershed
Authors: Skinner Q. D. , Adams J. C. , Rechard P. A. , Beetle A. A.
Published: April 2010

Nitrate-reducing bacteria, sulfate-reducing bacteria, fluorescent bacteria, and the total viable count were enumerated in three stream systems within a high mountain watershed over a period of two winters and two summers from 1970 to 1972. Spread plate and most probable number procedures showed that the number of fluorescent bacteria, sulfate-reducing bacteria, nitrate-reducing bacteria, and the total count were generally constant throughout the year at the lowest sampling site on the stream systems. However, in some cases and for short periods of time, the numbers of these bacteria appeared to be influenced by recreational use of the land and stream flow. For example, denitrifying bacteria increased in number during the winter recreational period and gave the lowest counts in July.
Acetylene reduction in artificial soil aggregates amended with cellulose, wheat straw, and xylan
Authors: Mayfield C. I. , Aldworth R. L.
Published: April 2010

When 1-cm diameter, waterlogged, sandy clay loam soil aggregates were amended with 2% (w/w) cellulose or 2% (w/w) wheat straw, significant C2H2-reduction activity developed whether the aggregates were incubated under aerobic or anaerobic gas phases. The only N2-fixing bacteria which proliferated were anaerobes or facultative anaerobes. Aerobic N2-fixing bacteria did not proliferate in any of the aggregates, even though a few were initially present in the soil. The anaerobic bacteria in aerobically incubated, cellulose-amended aggregates proliferated more slowly than those in the anaerobically incubated aggregates, but eventually produced a higher maximum rate of C2H2-reduction. The activities of the N2-fixing bacteria in straw-amended aggregates were similar under both aerobic and anaerobic gas phases. High amendment levels (20% w/w) altered the soil structure and the requisite anaerobic microsites were not developed as rapidly under aerobic incubation conditions and so the onset of C2H2-reduction activity was delayed.
Sur quelques propriétés d'un variant stable de Bacillus thuringiensis (Berliner) résistant à l'aflatoxine B1
Authors: Boutibonnes P.
Published: April 2010

A new aflatoxin B1 resistant strain of Bacillus thuringiensis (Berliner), designated "variant stable," was isolated in the presence of a mycotoxin lethal dose. The enzymatic and physiological properties of this slow-growing clone are in all respects similar to those of the original strain (in particular its resistance to a variety of antibiotic, antimitotic, or carcinogenous agents). Besides their radically opposite behavior with respect to aflatoxin B1, the colonies of these two strains differ only by their size and aspect: marginal and surface organization.[Journal translation]
Further studies on tularemia in Alaska: human tularemia
Authors: Miller Lawrence G.
Published: April 2010

The extent of tularemic infection in Indians in east-central Alaska and in Eskimos in southwestern Alaska was determined serologically. A greater percentage of Indians (6.9) had agglutinins than did Eskimos (3.6). Indications of recent infection were found only in the Indians. Neither of the two Indians who experienced seroconversion during the study had a history of clinical illness. A clinical case of tularemia in a laboratory worker is described, the severity of which seems to preclude the hare-tick strain of Francisella tularensis as the etiologic agent in inapparent infections in the aboriginal populations. Further epidemiological and epizootiologic investigations of tularemia in subarctic North America are indicated, since outbreaks associated with the water-rodent strain elsewhere suggest that its low virulence in the indigenous people may not be constant.
Further studies on tularemia in Alaska: virulence and biochemical characteristics of indigenous strains
Authors: Miller Lawrence G.
Published: April 2010

Cultures of Francisella tularensis isolated in Alaska were compared on the basis of their virulence and biochemical characteristics. Isolates from the hare, Lepus americanus Erxleben, and the hare tick, Haemaphysalis leporispalustris (Packard), conform to the description of F. tularensis nearctica Ols. in their ability to kill domestic rabbits, guinea pigs, and white mice, and in their ability to use glycerol and DL-citrulline. A rodent isolate conforms to the description of F. tularensis holarctica Ols. in its inability to kill domestic rabbits or guinea pigs, and in its inability to use either glycerol or DL-citrulline. Observations of hares experimentally infected with the hare isolate indicate that: (1) they may be fatally infected with less than 10 microorganisms; (2) the infection is fatal within 9 days; (3) no macroscopic lesions are apparent.
Cyst-like cells of Azotobacter vinelandii strain O
Authors: Cagle Gerald D.
Published: April 2010

Cells of Azotobacter vinelandii strain O which possess exinous regions (cyst-like cells) are characterized by electron microscopy from cultures of the organism incubated on butanol-containing media.
Similarities between nonsporulated yeast cells and asci
Authors: Steele S. D. , Miller J. J.
Published: April 2010

Yeast cells which did not sporulate in sporulation medium underwent some marked structural changes. Numerous vacuoles filled with material, possibly lipid, accumulated in the cytoplasm; the cell wall thickened and differentiated into an outer fibrillar and an inner particulate zone. The nonsporulated cells were viable but required 4–6 h at 27° to produce buds. In these respects the nonsporulated cells resembled asci or ascospores rather than vegetative cells.
Minicell formation in chloramphenicol-treated Bacillus cereus
Authors: Chung K. L. , Lin L. P.
Published: April 2010

Bacillus cereus incubated in a synthetic medium containing chloramphenicol, 19 μg/ml, a concentration which is slightly below the minimal inhibitory level, was observed to form from one to several minicells through a series of cytological changes including septum initiation, invagination and completion at the subpolar region of the cell, rupture of the peripheral cell wall along the circumferential path of this region, and finally cell separation. The minicells are spherical or spheroidal in shape. A small number of heart-shaped cells was also seen.
Biochemical identification of hospital enterobacteria by replica agar plating
Authors: Chadwick P. , Delisle G. J. , Byer M.
Published: April 2010

An identification system was developed for enterobacteria isolated frequently from hospital patients, involving a set of biochemical reactions on agar media. The media were inoculated by a replication apparatus also used for setting up antibiotic sensitivity tests. Cultures in a control series showed a close correlation between reactions on the agar media and classical tests in a fluid medium. Of a series of 2668 laboratory isolates of enterobacteria, 2292 were identified outright by the selected reactions, 160 required one further test, and 216 could be identified only after repeating the reactions or the performance of additional tests. The identification has the advantages of speed, economy, and simplicity and is recommended for hospital laboratories handling large numbers of enterobacterial cultures.
Butane-oxidation products as substrates for yeast growth
Authors: Wayman Morris
Published: April 2010

Samples of two streams, a primary oxidation product and a main recycle stream, were obtained from a large industrial plant oxidizing butane. These are not wastes, but streams within the production process, containing mixtures of oxidation products of butane. Their suitability as substrates for yeast growth was studied. Generation times and cell yields were determined for 11 different yeasts. The recycle stream gave unexpectedly low cell yields. Growth rates and yields were accordingly determined for 17 pure compounds representing the principal components of the two streams: alcohols, acids, esters, ketones, and an aldehyde, all of five carbon atoms or less. The 11 yeasts showed great variation in their ability to use these components. Yields of yeast based on the carbon content of the two samples were as expected from the individual components, but the recycle stream sample, which was rich in unutilizable ketones, was a poor substrate. The ketones may also have slowed the growth of the yeasts somewhat.
Action of chlorpromazine on spore-forming Bacillus species
Authors: Orlowski Michael , Goldman Manuel
Published: April 2010

The hypothesis that chlorpromazine inhibition of bacterial endospore germination acts at the level of hexose monophosphate shunt (HMP) dehydrogenases was tested and substantiated for Bacillus cereus T and Bacillus megaterium. However, this cannot be an exclusive mechanism of action in bacterial systems because inhibitory effects on growth and respiration are caused by the drug even when these HMP enzymes are not present in the organisms.
Bis(ethylenediamine)-1,10-phenanthrolinecobalt(III) bromide and the ligand ethylenediamine as sources of nitrogen for bacterial growth
Authors: Dollimore L. S. , Mather I. H. , Gillard R. D.
Published: April 2010

Pseudomonas stutzeri will grow on glucose with either the coordination compound bis(ethylenediamine)-1,10-phenanthrolinecobalt(III) bromide ([Co(en)2(phen)]Br3) or the ligand ethylenediamine as the sole source of nitrogen. The utilization of [Co(en)2(phen)]Br3 by P. stutzeri is presumed to involve initial reduction of the cobalt(III) complex to a labile cobalt(II) species which is in equilibrium with free ethylenediamine. After removal of ethylenediamine by the cells, the cobalt(II) and 1,10-phenanthroline remaining appear to inhibit ethylenediamine oxidation. Resting cells previously grown on ethylenediamine as the sole source of nitrogen are able to catalyze the degradation of ethylenediamine and ethanolamine. Ethanolamine-grown cells degrade ethanolamine but not ethylenediamine.
The soluble adenosine triphosphatase of Thiobacillus ferrooxidans
Authors: Adapoe Catherine , Silver Marvin
Published: April 2010

Adenosine triphosphatase (ATPase) from Thiobacilhis ferrooxidans was purified 55-fold. Polyacrylamide gel electrophoresis of the most purified fraction showed only one major band; histochemical analysis showed that the ATPase activity was associated with this band. The pH optimum is 9–10. The enzyme hydrolyzed ATP stoichiometrically to ADP and inorganic phosphate, the Km for this substrate being 7.75 × 10−3 M. GTP and ITP are alternate substrates, the Km values for these being 6.71 × 10−3 M and 3.12 × 10−3 M, respectively. ADP is slightly hydrolyzed. Magnesium, manganese, and calcium can serve as cofactors; Km values for these are 2.0 × 10−3 M, 9.4 × 10−4 M, and 8.0 × 10−4 M, respectively. The enzyme activity was not activated by either sodium or potassium, but a combination of the two ions were inhibitory. Azide and p-hydroxymercuribenzoate strongly inhibited the enzyme activity, whereas cyanide, dinitrophenol, and N, N′-dicyclohexylcarbodiimide (DCCD) were without effect. The enzyme was cold labile at 0 °C, but was more stable at 18–24 °C.
In vitro and in vivo interactions between Erwinia amylovora and related saprophytic bacteria
Authors: Erskine J. M. , Lopatecki L. E.
Published: April 2010

Under carefully controlled laboratory conditions, a highly virulent strain of Erwinia amylovora coinhabited susceptible host tissues with a yellow saprophytic bacterium, which was invariably isolated from fire blight infected trees, with or without producing symptoms of the disease depending on the status of a number of environmental factors, both climatic and physiological. In particular, variation of temperature and sucrose concentration determined, independently, the equilibrium of a readily reversible alternation of predominance of the two bacteria.It is suggested that E. amylovora may sometimes exist as an avirulent resident on the surface or within healthy host plants when environmental conditions favor growth of the yellow saprophyte rather than the pathogen. Such conditions, which are more likely to be obtained in midsummer and the fall, include temperature fall or rise below or above the optimum for E. amylovora, decreased humidity or diminution of sap flow, and increased sugar content in the host tissues.
Kinetics of Na+-dependent amino acid transport using cells and membrane vesicles of a marine pseudomonad
Authors: Sprott G. Dennis , Drozdowski Joseph P. , Martin Eugene L. , MacLeod Robert A.
Published: April 2010

Sodium ion is required for transport of L-alanine and α-aminoisobutyric acid (AIB) into cells and membrane vesicles of a marine pseudomonad. Initial rate data obtained at various Na+ and amino acid concentrations were tested for fit by least squares analysis to sequential and Ping-Pong equations. The sequential case is preferred statistically at the 99% confidence limit. Cotransport of AIB and Na+ in cells could not be detected, perhaps explained by efflux of Na+ shown to occur from these cells. The kinetic analysis is consistent with formation of a ternary complex involving Na+ and the amino acid.
The origin of fatty acids in the hydrocarbon-utilizing microorganism Mycobacterium vaccae
Authors: King D. H. , Perry J. J.
Published: April 2010

The fatty acid pattern in Mycobacterium vaccae strain JOB5 was examined after growth on n-alkanes (C14–C18), 1-alkenes (C14–C18), 2- or3-methyl octadecane, and 8-heptadecene. It was evident that monoterminal oxidation of n-alkanes was followed by β-oxidation and that both parent fatty acid and products of β-oxidation were incorporated into cellular lipids. Radioactive experiments demonstrated that there was desaturation of long-chain fatty acids. There was no evidence of chain elongation. Growth on 1-alkenes resulted in the incorporation of fatty acids that were products of two primary modes of oxidation: (1) methyl group attack resulting in ω-unsaturated fatty acids and (2) double-bond attack resulting in the removal of one carbon from the substrate. Cells of strain JOB5 grown on 2- and 3-methyl octadecane contained the corresponding iso- or anteiso-fatty acids in significant quantity. Cells cultured on 8-heptadecene contained 8- and 9-heptadecenoic acids, 6- and 7-pentadecenoic acids, 9- and 10-methyl hep-tadecanoic acids, and 7- and 8-methyl pentadecanoic acids. Fatty acid composition (C13 to C19) was affected by substrate chain length and was additionally modified by cellular control mechanisms.
Indicator media for microorganisms degrading chlorinated pesticides
Authors: Loos M. A.
Published: April 2010

A bromocresol purple liquid indicator medium and an eosin – methylene blue agar have been developed for the demonstration and isolation of microorganisms able to degrade the chlorinated herbicide, 2,4-dichlorophenoxyacetic acid (2,4-D). Plates of the eosin – methylene blue agar indicate individual 2,4-D-degrading bacterial colonies. Both indicator systems show the production of acid, presumably hydrochloric, during degradation of the 2,4-D in the media. Concentrations of 2,4-D required to give an acid reaction in media with varying concentrations of yeast extract were determined; the production of about 0.24 mmol of hydrochloric acid seems necessary to counteract the buffering effect of 100 mg of metabolized yeast extract. Acid production from the herbicide, 4-chloro-2-methylphenoxyacetic acid (MCPA), which in the salt form could yield only small amounts of hydrochloric acid, was inconsistent. The two indicator media should be useful in investigations of the microbial degradation of other acid-yielding halogenated pesticides.
Comparative ultrastructure of methanogenic bacteria
Authors: Zeikus J. G. , Bowen V. G.
Published: April 2010

Electron-microscopic studies using thin sections revealed that methane-producing bacteria were an ultrastructurally diverse group. Fine structure and morphological characteristics separated these bacteria into four discrete cell types. Methanogenic bacteria displayed a gram-positive cell wall that varied considerably among different cell types. Differences in granular inclusions, reserve materials, and intracytoplasmic membranes were observed. Unique ultrastructural features were not shared by all methanogenic species studied.
Endosymbiosis in a leafhopper, Helochara communis Fitch (Cicadellidae: Homoptera): symbiote translocation and auxiliary cells in the mycetome
Authors: Chang K. P. , Musgrave A. J.
Published: April 2010

At times, symbiote populations in mycetomes of Helochara communis are apparently increased by translocation of symbiotes from adjacent mycetocytes. These symbiotes appear to reproduce in mycetomes and become phagocytosed by 'auxiliary' cells (probably hemocytes) that invade mycetomes at zones of disruption supposedly resulting from reproduction of the translocated symbiotes. Some phagocytosed symbiotes degenerate in large vacuoles; others become lodged in smaller vacuoles that supply a third membrane. The hemocytes fuse and form additional mycetomal syncytia.
Structural features determining the antibiotic potencies of natural and synthetic hop bitter resins, their precursors and derivatives
Authors: Schmalreck Arno F. , Teuber M. , Reininger W. , Hartl A.
Published: April 2010

Twenty-six hop bitter resins, some hitherto not investigated, were tested for antimicrobial activities. Gram-positive bacteria were much more sensitive than Gram-negative ones. The inhibitory effect against Bacillus subtilis 168 was measured by several methods and the general rule could be established that the antibiotic properties are mainly dependent on the hydrophobic parts of the molecules. Thus the acyl-lupuphenones (2-acyl-3, 5-4, 4′, 6-tri(3-methyl-2-butenyl)-cyclohexane-triones (1, 3, 5)) having three prenyl and one acyl side chain are the most active substances. Their minimum inhibitory concentration (MIC) increases from the capro (0.5 μM) to the aceto derivative (11 μM). Any substitution with hydrophilic functions or loss of hydrophobic groups causes reductions in biological activity. This is most evident with the corresponding acyl-phloroglucine precursors (2-acyl-1, 3, 5-trihydroxybenzenes) which lack the three prenyl side chains (MIC, 110 to 5050 μM respectively). Conversion of the central six-membered ring structure into a five-membered one results in additional losses of antimicrobial activity. These findings support the proposal that the lipophilic region of the cell membrane represents the target site for the hop bitter resins.
Comparison of the effects of three fluorocarbons on certain bacteria
Authors: Auken O. W. Van , Healy J. , Kaufmann A. J.
Published: April 2010

Three fluorocarbons were tested to determine their effect on bacterial growth. Freon 11 and 21 in various concentrations had an inhibitory effect on selected test organisms, but Freon 22 had no effect. Both aerobic and anaerobic microorganisms, as well as gram-positive and gram-negative species, were included among the bacteria tested. Freon 11 and 21 caused a similar response with Freon 11 being more inhibitory to some species and Freon 21 more inhibitory to others. Inhibition was dependent on the concentration of the halocarbon and resulted in decreased respiration rates at all concentrations tested. Results reported here indicate that the action of the fluorocarbons tested is bactericidal rather than bacteriostatic. Serratia marcescens and Clostridium botulinum were the species most sensitive to the halocarbons tested.
Thiobacillus acidophilus sp. nov.; isolation and some physiological characteristics
Authors: Guay Roger , Silver Marvin
Published: April 2010

After a brief exposition to glucose, Thiobacillus acidophilus was isolated from a culture of iron-grown T. ferrooxidans. Physicochemical analysis of its DNA showed a G + C content of 62.9–63.2%. The new isolate grows best at 25–30 °C and at pH 3.0. Growth is possible between pH 1.5 and 6.0. Thiobacillus acidophilus is apparently strictly aerobic. Ammonium salts are the only suitable source of nitrogen. The bacterium is a facultative autotroph. In addition to elemental sulfur, it obtains energy from organic compounds such as D-glucose, D-galactose, D-fructose, D-mannitol, D-xylose, D-ribose, D-arabinose, L-arabinose, sucrose, sodium citrate, malic acid, dl-aspartic acid, and dl-glutamic acid.Thiobacillus acidophilus possesses the key enzymes of the tricarboxylic acid (TCA) cycle including NAD- and NADP-linked isocitric dehydrogenase and α-ketoglutarate dehydrogenase, and the key enzymes of the hexose monophosphate pathway (glucose-6-phosphate and 6-phosphogluconate dehydrogenase, and fructose 1,6-diphosphate aldolase). NADH oxidase has been found in particulate fraction of extracts. Rhodanese and thiosulfate oxidase have also been detected.
Diagnosis of rubella virus infections. I. A comparison between Vero and BHK-21 cells for the detection of specific IgG and IgM antibodies by immunofluorescence
Authors: Payment Pierre , Roy Lucille , Gilker Jean-Claude , Chagnon André
Published: April 2010

Vero cells were more suitable then BHK-21 cells for the detection of rubella-specific 1gG antibodies because the nonspecific fluorescence was minimal. However, BHK-21 cells were found more sensitive than Vero cells for the detection of rubella-specific IgM antibodies.
Some effects of petroleum on estuarine and marine microorganisms
Authors: Walker J. D. , Colwell R. R.
Published: April 2010

Degradation of mixed hydrocarbon substrate in a system comprising water from an environment relatively free of oil and a sediment inoculum from an oil-contaminated site was significantly greater than when sediment from the non-oil-contaminated environment served as inoculum. Mixed hydrocarbon substrate, however, was observed to have a limiting effect on the growth of autochthonous bacteria from the non-oil-contaminated estuarine source. Growth and cell yield were similarly reduced when marine sediment bacteria were cultured in seawater supplemented with mixed hydrocarbon substrate. The addition of a South Louisiana crude oil or a No. 2 fuel oil to water and sediment collected from a marsh area of Chesapeake Bay showed no limiting effects on growth of the total heterotrophic microbial flora when examined over a 28-day period. However, results of these studies indicate that the effects of petroleum on microorganisms should be examined carefully under conditions closely approximating those in situ.
Measurement of bacterial and fungal contributions to respiration of selected agricultural and forest soils
Authors: Anderson J. P. E. , Domsch K. H.
Published: April 2010

A technique using selective inhibitors was used to estimate the relative contributions of bacterial and fungal populations to the respiration of six soils and one litter sample. The ratios of bacterial to fungal respiration in the four agricultural soils, given in percentage of the total microbial activity, ranged from 10/90 to 35/65, with the average ratio being about 30/70. In the forest soils, the ratios were 20/80 and 30/70, and in a beech litter sample, the ratio was 40/60. The fungi clearly dominated in all samples. The ratios were not found to be pH related. The difficulties which had previously limited the use of selective inhibitors for in situ soil ecological investigations, such as insufficient inhibitor specificity, inhibitor inactivation or degradation, and errors of measurement caused by elimination of competitor populations, were either resolved or methodologically avoided in the experiments. Inhibitor selectivity was demonstrated using both mixed and pure cultures of microorganisms from each soil. Through the use of experiments with short incubation periods (6–8 h), problems with population shifts and inhibitor degradation were eliminated.
Variation in the activity levels of selected enzymes of Erwinia amylovora 595 in response to changes in dissolved oxygen tension and growth rate of D-glucose-limited chemostat cultures
Authors: Farago D. A. , Gibbins L. N.
Published: April 2010

Chemostat cultures of Erwinia amylovora 595, grown in mineral salts – nicotinic acid medium at 30 °C, and limited by D-glucose concentrations in the presence of dissolved oxygen tensions (D.O.T.) greater than about 6 mm Hg, became limited by oxygen availability below about 4 mm Hg. This latter limitation was accompanied by a marked increase in acid production as the D.O.T. was depressed. The transition between D-glucose- and oxygen-limitation was also characterized by a maximum in succinate oxidase activity, and a minimum in the in situ respiration. D-Glyceraldehyde-3-phosphate dehydrogenase and D-fructose-1,6-diphosphate aldolase showed small reductions in specific activity in the region 4–6 mm Hg D.O.T., but further reduction to 2 mm Hg resulted in a marked increase in the specific activity of aldolase. Malate dehydrogenase followed the converse trend, and attained very low activity levels when the D.O.T. decreased beyond the lower limits of detection. The in situ respiration was maximal at 2 mm Hg D.O.T., while potential respiration values were minimal at 2 mm Hg, and maximal at about 8 mm Hg D.O.T. The in situ respiration rate was proportional to dilution rate (D), in presence of excess oxygen, up to 0.18 h−1, after which a marked diminution occurred and continued until the wash-out rate was attained. Succinate oxidase activity decreased with increase in dilution rate, but remained constant above D = 0.18 h−1. Malate dehydrogenase showed a persistent decline with increase in dilution rate, while D-glyceraldehyde-3-phosphate activity increased somewhat at higher dilution rates. The data are interpreted in terms of two transition points, at 6 and 2 mm Hg D.O.T., and of a change from respiratory to fermentative metabolism at low D.O.T., and at high dilution rates.
The ultrastructure of the cellulolytic bacterium Cellvibrio fulvus
Authors: Berg B. , Hofsten Angelica V.
Published: April 2010

Thin sections of the cellulolytic bacterium Cellvibrio fulvus were investigated before and after treatment with polymyxin B and Triton X-100. The Gram-negative vibrio appeared to have no separate stained g2 layer between the L and C membranes. Cells lysed after treatment with polymyxin or swelled in the presence of 5% sucrose. Blebs were formed from the L membrane, and the inner structure of the cells changed.Triton X-100 lysed cells even in the presence of 20% sucrose. The flagellum disappeared before lysis; one of the membranes was dissolved; and no organized inner structure could be seen.
Effect of chlorpromazine on the respiration and hexose monophosphate dehydrogenases of gram-negative bacteria
Authors: Orlowski Michael , Goldman Manuel
Published: April 2010

The drug chlorpromazine inhibits respiration in several gram-negative bacteria. The enzymes glucose-6-phosphate dehydrogenase and 6-phosphogluconate dehydrogenase from these microorganisms are not affected by the drug.
Diagnosis of rubella virus infections. II. A comparison between incident and transmitted light fluorescence for the detection of specific IgM antibodies
Authors: Payment Pierre , Roy Lucille , Gilker Jean-Claude , Chagnon André
Published: April 2010

The fluorescence obtained with an incident light system is higher than that obtained with a transmitted light system. Examination time is reduced and the strain on the eyes, after long periods, is reduced. However, the results are the same whatever the system used.
Partial purification and characterization of the lipase of a facultatively psychrophilic bacterium (Acinetobacter O16)
Authors: Breuil Colette , Kushner D. J.
Published: April 2010

The extracellular lipase(s) of the psychrophile Acinetobacter O16 was studied. When the enzyme was precipitated by (NH4)2SO4 and passed through a Sephadex G 200 column, two peaks of lipase activity appeared. The larger peak, which behaved like a substance of high molecular weight, being eluted in the void volume, was purified 250-fold over the crude enzyme (culture supernatant) by passage through a DEAE Sephadex column. When the enzyme was applied to a DEAE-cellulose column it could not be eluted unless it had first been treated with the detergent Triton X 100. It is suggested that lipids or phospholipids make up an important part of the molecule.The activity of the crude and partly purified enzymes was studied in relation to pH and temperature optima. Lipases from the psychrophilic Acinetobacter O16 and from the mesophilic Acinetobacter O4 reacted in the same way to temperature. The crude enzyme from Acinetobacter O16 was more temperature-stable than the purified enzyme.
An experimentally pathogenic Bacillus species. I. Description and characterization of the organism
Authors: Stamper Jr. Hugh B. , Chorpenning Frank W.
Published: April 2010

A previously undescribed Bacillus species has been characterized. The organism was isolated from a blood transfusion bottle implicated in a fatal bacteriogenic transfusion reaction and has been examined from a number of different aspects to characterize it as completely as necessary to provide identification. It was placed into group 3 of the genus Bacillus on the basis of its cellular morphology, the morphology of the sporangium, and the location of the spore within the cell. There are only three other species described in this group. Since the organism differed markedly from each of these, it appears to represent a new species.
Characterization of branched and unsaturated fatty acids in Mycobacterium vaccae strain JOB5
Authors: King D. H. , Perry J. J.
Published: April 2010

After growth of Mycobacterium vaccae strain JOB5 on acetate or propane, the cellular fatty acids were isolated and identified by a combination of gas-chromatographic, mass-spectral, and chemical means. The fatty acids ranged from C12 to C19 and were a mixture of saturated, monounsaturated, and methyl-branched components. The double bond was in the Δ9 position in the C15 to C18 unsaturated acids. The single methyl branch was located on the C10 position of Br-C17, Br-C18, and Br-C19 fatty acids. Branched-chain synthesis occurs at the expense of an unsaturated precursor fatty acid; the double bond serves as the site of methylation. Results suggest that S-adenosylmethionine is the methyl donor involved.
Partial purification and properties of a β-glucosidase from Erwinia herbicola Y46
Authors: Garibaldi A. , Gibbins L. N.
Published: April 2010

A constitutive β-glucosidase of Erwinia herbicola Y46 was studied as a prerequisite to an assessment of its significance in the release of bacteriotoxic aglycones from plant β-glucosides, and the possible effects of the aglycones on the course of such plant diseases as "fire-blight." The enzyme was purified 86.5-fold from crude extracts of cells grown on yeast beef broth. Ammonium sulfate precipitation, DEAE-cellulose fractionation, and gel filtration through Sephadex G-100 resulted in a preparation having one peak of activity on isoelectrofocussing, on gel filtration through Sephadex G-200, and on polyacrylamide gel electrophoresis. The latter techniques demonstrated, in addition to the major protein band associated with activity, a single minor impurity. The enzyme was active against p-nitrophenyl-β-glucoside (p-NPG) and phloridzin, but showed only very slight activity against salicin and arbutin, and no detectable activity against β-methyl-D-glucoside, cellobiose, lactose, and esculin. The production of β-glucosidase was maximum at the late log phase of growth on yeast beef broth medium and declined somewhat thereafter. The incorporation of inducers (carbohydrates) in defined basal medium resulted in only small variations in specific activity in the resulting cells. The activity (p-NPG substrate) was not inhibited by D-glucose, phloretin, esculin, salicin, arbutin, lactose, or cellobiose, but was slightly inhibited by 1.0 mM phloridzin. Slight inhibition was observed in the presence of sulfhydryl reagents (iodoacetamide, p-chloromercuribenzoate), but sodium azide, ethylene-diaminetetraacetic acid, Cu2+, and Zn2+ ions produced no effect. The activity was stable, in both crude and purified preparations, over the pH ranges 6.0–7.5 (100% activity) and 4.5–>8.5 (50% activity). The enzyme retained 80% activity after 30 min at 50 °C, but only 25% after 30 min at 60 °C. The enzyme had a mean Km value (phloridzin) of 1.35 × 10−4 M, an isoelectric point of 4.75, a molecular weight, determined by Sephadex G-200 gel filtration, of about 122 000, and an optimum pH for activity of 6.5–7.0.
Fungal fimbriae. II. Their role in conjugation in Ustilago violacea
Authors: Day A. W. , Poon N. H.
Published: April 2010

During conjugation in the anther smut fungus Ustilago violacea cells of opposite mating type first pair tightly and then develop a conjugation tube or bridge between them. The cells of both mating types are covered in long fine hairs or fimbriae, some of which appear to end in knobs. Experiments involving enzyme treatments of the cell surface indicate that these fimbriae do not play an essential role in cell pairing, instead pairing seems to be initiated when one or both mating types produce amorphous masses of α-amylase-sensitive material. Electron micrographs, enzyme and inhibitor studies, and experiments using restrictive temperatures suggest, however, that fimbriae may be essential for the later stages of conjugation i.e. development of the conjugation tube. If so, it is suggested that they may permit the exchange of macromolecules between the conjugating cells, initiating localized wall-softening and wall-breakdown.
Effects of potassium azide on soil microbial populations and soil enzymatic activities
Authors: Kelley W. D. , Rodriguez-Kabana R.
Published: April 2010

Preplant applications of potassium azide (KN3) to pine nursery beds were evaluated for effect on the soil microflora and on soil enzyme activity where either plastic-sealing or water-sealing techniques were used. Two weeks after incorporation of azide (0–224 kg/ha), soil samplings revealed reduced populations of bacteria and fungi and a corresponding decline in invertase and amylase activities. These effects were proportionate to the amount of azide used and were more pronounced in plastic-sealed plots. Phosphatase activity was little affected. Five weeks after azide application, bacterial populations were higher in treated plots than in controls. Greater numbers of bacteria were recorded from plastic-sealed plots and highest populations coincided with plots receiving the highest rates of azide, regardless of the sealing technique. Fungal populations at this sampling were generally less in treated plots than in the controls, but were higher under plastic seal. At this time, changes in invertase and amylase activities did not correspond to increased microbial numbers. Sixteen weeks after applications of KN3, bacterial populations in treated plots did not differ significantly from controls, but remained higher in plastic-sealed than water-sealed plots. Fungal populations under plastic seal had changed little and remained significantly lower in treated water-sealed plots than in controls. The earlier recorded reduction in invertase and amylase activities was still evident at the final sampling.
A large new Streptococcus bacteriophage
Authors: Ackermann Hans-W. , Caprioli Teresa , Kasatiya Shanti S.
Published: April 2010

Phage VD13 possesses a large, elongated head and a long, non-contractile tail. It is active on group D streptococci and contains double-stranded DNA. The phage produces several rare kinds of head malformations, notably polymorphic mottled structures and giant heads which probably contain DNA.
Isolations of California encephalitis virus from tundra mosquitoes
Authors: Wagner R. J. , DeJong C. , Leung M. K. , McLintock J. , Iversen J. O.
Published: April 2010

Four isolations of California encephalitis virus were made from tundra mosquitoes of the Aedes hexodontus-punctor group collected in the Keewatin District, Northwest Territories. The viral isolates were identified as belonging to the snowshoe hare subtype of California encephalitis virus.
Dissimilation of the lignin model compound veratrylglycerol- β -(o-methoxyphenyl) ether by Pseudomonas acidovorans: initial transformations
Authors: Crawford R. L. , Kirk T. Kent , McCoy Elizabeth
Published: April 2010

The initial transformations of veratrylglycerol-β-(o-methoxyphenyl) ether (compound 1) effected by Pseudomonas acidovorans are demethylation of the 4-methoxyl group of the 3,4-dimethoxyphenyl portion of the molecule, and a NAD+-linked dehydrogenation of the benzyl alcohol group. Based on these findings and those described before, an overall degradation scheme is postulated.
Detection and measurement of bacterial catalase by the disk-flotation method using the Catalasemeter®
Authors: Charbonneau R. , Therrien J. , Gagnon M.
Published: April 2010

Using the disk-flotation method and a Catalasemeter®, catalase production by 13 different species of bacteria was studied qualitatively and quantitatively.