bluuebunny/crossref_metadata_2025 huggingface dataset:
Evidence for the cotransfer of genetic markers in Pseudomonas solanacearum strain K60
Authors: Boucher C. A. , Sequeira L.
Published: April 2010

A procedure in which transfer of genetic information between genetically distinct derivatives of strain K60 of Pseudomonas solanacearum occurred is described. Genetical analysis of recombinants demonstrated the transfer of an unselected marker, and the linkage of genes determining resistance to streptomycin and rifampicin.
An examination of enzyme production by Phytophthora spp. on solid and liquid media
Authors: McIntyre John L. , Hankin Lester
Published: April 2010

Solid media were used to determine which extracellular hydrolytic enzymes are produced by Phytophthora parasitica; P. parasitica var. nicotianae, races 0, 1, and 3; and several other Phytophthora spp. Most isolates produced RNase, DNase, phosphatase, lipase, and cellulase uniformly. All race 3 isolates of P. parasitica var. nicotianae exhibited protease activity on a medium containing gelatin, while only 33 and 60% of the race 0 and I isolates, respectively, and 14% of the P. parasitica isolates did so. Addition of sorbose to this medium enabled the detection of protease activity by most of the isolates. Amylase activity, measured in the culture fluid, was higher in race 3 than in races 0 or 1 of P. parasitica var. nicotianae and P. parasitica.
The response of cell walls of Bacillus subtilis to metals and to electron-microscopic stains
Authors: Beveridge T. J.
Published: April 2010

Purified cell walls of Bacillus subtilis were subjected to solutions of 40 independent metals and the metal uptake, the electron-scattering power of thin sections, and the type of staining response evaluated. This was repeated for six typical electron-microscopic stains (uranyl acetate, uranyl magnesium acetate, osmium tetroxide, Os-meth, osmium-dimethylethylenediamine, and ruthenium red) and one new staining reagent (a potassium platinum chloride – dimethylsulfoxide complex) whose specificity is for amine functions. The reaction of select metals can be specific in terms of both uptake and staining response. Of the metals studied most transition elements had a high affinity for the wall fabric and some (i.e., Sc III, most lanthanides, U IV, Zr IV, Hf IV, Fe III, Pd II, Ru III, and In III) may be suitable as contrasting agents for electron microscopy. Furthermore, when the thickness of metal-reacted walls was compared to freeze-each and ultracryotomy data, statistical-dimensional differences were commonly seen, which indicates that wall ultrastructure can be profoundly affected by the type of metal and (or) staining reagent.
Studies on circulating gonococcal antibodies and antigens
Authors: Kwapinski George , Kwapinski Elke , Webb Charles J.
Published: April 2010

One hundred human sera obtained from acute gonococcal disease and 100 sera from non-gonococcal diseases or healthy persons were concentrated four times and examined for the presence of circulating gonococcal antigens and antibodies by means of a counterimmunoelectrophoresis (CIE) and delayed hypersensitivity assay. Antibodies reacting with cytoplasmic gonococcal antigens were detected by CIE in 92% of sera received from patients suffering from acute gonococcal disease. Gonococcal antigens were found in the concentrated sera of 82.3% of patients on the basis of dermal reactions observed upon injections of these sera into the skin of rabbits sensitized with disrupted gonococci; 51.8% of the patients' sera gave delayed hyper sensitivity reactions in rabbits sensitized with cytoplasmic antigens of N. gonorrhoeae. Control sera from healthy people and those with non-gonococcal diseases did not react with any of the preparations tested.
Polyphosphate-deficient mutants of Anacystis nidulans
Authors: Vaillancourt S. , Beauchemin-Newhouse N. , Cedergren R. J.
Published: April 2010

Polyphosphate-deficient mutants of Anacystis nidulans have been isolated by either ethyl methanesulfonate (EMS) or N-methyl nitrosoguanidine (NTG) mutagenesis and penicillin-enrichment techniques. Mutagenised stock was preincubated in a medium lacking sulfate, then transferred to a phosphate-lacking medium before penicillin treatment. Many single-colony isolates, in contrast to wild-type, show little growth in absence of phosphate, and have altered polyphosphate kinase levels indicating that the lesions affect either the activity or the expression of this enzyme. In these same mutants radioactive phosphate incorporation is severely retarded. Electron micrographs confirm the absence of polyphosphate granules in some mutants.
The lipopolysaccharide (R type) as a common antigen of Neisseria gonorrhoeae. II. Use of hen antiserum to gonococcal lipopolysaccharide in a rapid slide test for the identification of N. gonorrhoeae from primary isolates and secondary cultures
Authors: Wallace R. , Ashton F. E. , Ryan A. , Diena B. B. , Malysheff C. , Perry M. B.
Published: April 2010

An antiserum has been prepared in hens to R-type gonococcal lipopolysaccharide (LPS) and used in a simple slide-agglutination test for the identification of Neisseria gonorrhoeae. Anti-LPS serum agglutinated gonococcal cells representative of the four colony types of N. gonorrhoeae. Absorption of the antiserum with LPS removed the agglutinating activity. Secondary cultures (1120) were tested without observation of the colony type and all were agglutinated. No agglutination occurred with strains of Neisseria meningitidis, Neisseria lactamica, non-pathogenic Neisseria, Pseudomonas aeruginosa, Branhamella catarrhalis, or with species of lactobacilli and Acinetobacter. Cross-reactivity of the antiserum occurred with some streptococci. The anti-LPS serum was used to identify N. gonorrhoeae in primary isolates from the cervix, urethra, and pharynx. Of 251 gonococcal isolates tested, 249 were agglutinated by the antiserum, while all of the corresponding secondary cultures were agglutinated. The antiserum did not agglutinate N. meningitidis found in primary isolates from pharyngeal specimens. Anti-LPS hen serum should be useful for the rapid identification of N. gonorrhoeae in primary isolates or secondary cultures.
Health-indicator bacteria in water-surface microlayers
Authors: Dutka B. J. , Kwan K. K.
Published: April 2010

The distribution patterns of a variety of bacteria in the surface microlayer, 20 cm and 100 cm below the surface of rivers, open lake waters, and off docks are presented. Implications of this three-season study are that conventional sampling techniques underestimate the true microbiol densities.
Immunological relationships of some non-pathogenic Neisseria
Authors: Russell R. R. B. , Johnson K. G. , McDonald I. J.
Published: April 2010

A collection of nine stock strains of non-pathogenic Neisseria species and one strain of Branhamella catarrhalis has been examined serologically by a simple immunodiffusion technique utilising cultures growing on solid medium.
Effet de substances tensio-actives sur Mycobacterium tuberculosis et Mycobacterium bovis. Obtention de mycobactéries chromogènes
Authors: Lafont Jeanne , Lafont Philippe
Published: April 2010

In 18 strains of M. tuberculosis and M. bovis it has been possible to demonstrate the existence, in pure cultures, of elements able to grow in vitro in scotochromogenic mycobacteria.The experimental method used includes a dispersion, under shaking, of organisms in different surface-active agents.The chromogenic strains isolated during the experimentation are eugonie. and PAS- and INH-resistant. Their experimental virulence is different from that of tubercle bacillus.We discuss the signification of this dissociation phenomenon inductible by surface-active agents.
Detection of Salmonella enterotoxin using rabbit ileal loops
Authors: Sbdlock D. M. , Deibel R. H.
Published: April 2010

The presence of an enterotoxin produced by Salmonella in broth culture has been demonstrated by using the rabbit ileal loop model. Response by the animal to enterotoxin in sterile culture supernatant fluids is enhanced when the intestinal lumen is washed with a mucolytic agent prior to the administration of toxin. Fluid secretion in untreated intestinal loops was also observed if enterotoxin was administered with a live, invasive Salmonella strain which did not evoke a secretory response. A limited survey of Salmonella isolated from clinical and food sources indicated the common occurrence of enterotoxin production, and stock cultures maintained the ability to produce the toxin. The host-adapted species which were tested varied in their ability to produce enterotoxin.
Effects of heavy metals and other trace elements on the fermentative activity of the rumen microflora and growth of functionally important rumen bacteria
Authors: Forsberg C. W.
Published: April 2010

The inhibitory effects of high concentrations of essential and non-essential trace elements were tested on the rumen microflora using the rate of fermentation in vitro as the assay. The elements (and the concentration causing 50% inhibition) in decreasing order of toxicity were Hg2+ (20 μg/ml), Cu2+ (21 μg/ml), Cr6+ (70 μg/ml), Se4+ (73 μg/ml), Ni2+ (160 μg/ml), Cd2+ (175 μg/ml), As3+ (304 μg/ml), and As5+ (1610 μg/ml). The elements tested that were either weak or non-inhibitory at concentrations greater than 400 μg/ml included Zn2+, Cr2+, Fe2+, Mn2+, Pb2+, and Co2+. Methylmercury was as inhibitory as mercuric chloride to the fermentation. When the inhibitory effect of Cd2+ was tested on separated bacterial and protozoal fractions, it was more inhibitory to the bacteria. The inhibitory effects of trace elements were also determined for a number of axenic cultures of rumen bacteria. The bacteria which most frequently exhibited the greatest sensitivity were Bacteroides succinogenes, Ruminococcus albus, Bacteroides amytophilus, and Eubacterium ruminantium. Those often exhibiting intermediate sensitivities included Butyrivibrio fibrisolvens, Selenomonas niminantium, and Megasphera elsdenii, while Streptococcus bovis was very refractory to all elements tested. Rumen fluid provided a modest protective effect for the bacteria.
Hydrogen evolution and uptake by nodules of soybeans inoculated with different strains of Rhizobium japonicum
Authors: Carter Kevin R. , Jennings Nancy T. , Hanus Joe , Evans Harold J.
Published: April 2010

Hydrogen evolved by nitrogenase may be recycled by a hydrogenase present in some legume nodules. Anoka and Portage cultivars of soybeans were inoculated with each of 8 and 24 strains, respectively, of Rhizobium japonicum and surveyed for H2 evolution and C2H2 reduction rates, nodule weight, and plant dry weight. Six of the strains (3I1b 110, USDA 122, USDA 136, 3I1b 6, 3I1b 142, and 3I1b 143) which exhibited no H2 evolution in air were shown to take up H2. The relative efficiencies of nitrogenase energy utilization based on C2H2 reduction rates of nodules ranged from 0.96 to 1.0 for the six strains. Nodules formed by strain WA 5099-1-1 evolved small amounts of H2 in air and had a relative efficiency of 0.92. Nodules formed by the remaining 25 strains had relative efficiencies ranging from 0.41 to 0.80.A H2-evolving (3I1b 123) and a non-H2 evolving (3I1b 143) strain were tested on seven soybean cultivars to determine the effect on the expression of hydrogenase. Nodules formed by strain 3I1b 143 exhibited an efficiency of 1.0 on the following cultivars: Amsoy 71, Anoka. Bonus, Clark 63, Kent, Peking, and Portage. Relative efficiencies from 0.63 to 0.77 were determined for the five cultivars nodulated by strain 3I1b 123. From the experiments with these cultivars, the capacity to recycle H2 produced from the nitrogenase system appears to be determined by the R. japonicum strain.
Effect of osmotic potential, pH, and temperature on the growth of a helical, motile mycoplasma causing corn stunt disease
Authors: Liao C. H. , Chen T. A.
Published: April 2010

Growth characteristics of corn stunt spiroplasma, a helical, motile mycoplasma, were studied over a range of osmolality, pH, and temperature in a simple medium containing 20% (v/v)agamma horse serum, 1.5% (w/v) PPLO broth, and various concentrations of sucrose. The spiroplasma was able to grow in a wide spectrum of osmolalities from 360 to 1120 mosm. Optimal growth was observed in media that contained 0.25–0.35 M sucrose. The organism became longer and thinner in media adjusted to 0.65 M sucrose or more. The spiroplasma lost helicity and motility immediately after transfer to media at pH 5.4 or lower. Optimal pH for growth was 7.2. No growth was observed at pH lower than 5.4 or higher than 8.0. Optimal temperature for growth was 32 °C. Very little or no growth was observed at temperatures lower than 15 °C or higher than 35 °C.
Chlamydiae, rickettsiae, and their cell wall defective variants
Authors: Kordová Nonna
Published: April 2010

Inapparent chlamydial and rickettsial infections are an important source of the dissemination of the parasites and may cause explosive outbreaks of severe diseases in man and animal. However, it is enigmatic how these obligate intracellular microbes induce latency and why or how inapparent infections convert into active disease. Currently, microbiologists believe that chlamydiae and rickettsiae are gram-negative bacteria unique in their intracellular habitat. This review presents evidence that these organisms have another peculiarity; namely, defective cell walls present throughout much of their life cycle. In this survey, the properties of the small and large forms of chlamydiae and rickettsiae are reexamined with regard to the current knowledge of cell wall defective variants of free-living bacteria. Data are presented in support of the concept that chlamydiae and rickettsiae are cell wall defective microbes whose small 'bacterial' forms have lost the ability to reproduce as bacteria during evolution; the large forms including ultrafilterable phases of the life cycle of these parasites are responsible for inapparent infections of healthy carriers, whereas conversion into small 'bacterial' forms may cause, under appropriate conditions, manifest diseases. This concept may provide challenging and profitable directions in the search to explain puzzling phenomena associated with chlamydiae and rickettsiae.
Comparison of rotavirus strains by hemagglutination inhibition
Authors: Spence L. , Fauvel M. , Petro R. , Babiuk L. A.
Published: April 2010

Rotaviruses have been shown to be of importance as aetiologic agents of gastroenteritis in infants and in domestic animals of several species. Hemagglutinins were prepared from two Canadian isolates of bovine rotavirus and from one isolate of a simian rotavirus. A United Kingdom isolate of bovine rotavirus was shown not to possess hemagglutinating activity, indicating a strain difference between a Canadian and a United Kingdom bovine rotavirus. In hemagglutination-inhibition (HAI) tests a rabbit hyperimmune (two injections) serum, prepared to one of the bovine rotaviruses, was not helpful in distinguishing the two bovine viruses because of cross-reactions between the viruses. However, it was possible to distinguish the bovine viruses from the simian virus with this serum.When guinea pig immune sera were prepared to the four rotavirus strains and tested with the three hemagglutinins in the HAI test, antigenic differences between the four strains of rotavirus were demonstrated. Hyperimmune guinea pig serum prepared to a strain of human rotavirus did not inhibit any of the three hemagglutinins indicating that the human strain is different from the three rotavirus strains which gave hemagglutinins.
Homologous and cross-reacting antibodies in the sera of gnotobiotic rats
Authors: McLeod Joy C. , Balish Edward
Published: April 2010

Sera from Sprague–Dawley rats monoassociated with Clostridium perfringens, C. tertium, C. bifermenlans, Staphylococcus aureus, Escherichia coli, Proteus mirabilis, or Klebsiella pneumoniae for 4 weeks were assayed for homologous and cross-reacting antibodies against antigens on a variety of bacteria. A passive hemagglutination assay, with the antigen(s) consisting of bacteria conjugated to tanned sheep red blood cells, was used to assess antibody titers. Both homologous and cross-reacting antibodies were detected in sera that were collected from the monoassociated animals. Sera from monoassociated rats had agglutinating antibody to genera of bacteria that had not colonized their gastrointestinal tract. Although S. aureus shared some antigens with three species of Clostridium, the relationship was not reciprocal. Sera from rats monoassociated with E. coli, P. mirabilis, or K. pneumoniae had cross-reactive antibody against gram-positive and gram-negative bacteria, but did not have antibodies that could agglutinate H. influenzae type b. Monoassociation with C. perfringens resulted in the production of antibodies against a variety of gram-positive and gram-negative bacteria, but it did not induce cross-reactive antibodies against Corynebacterium diphtheriae, streptococci (groups A, C, and G), or Staphylococcus epidennidis.
New Minto virus: a new rhabdovirus from ticks in Alaska
Authors: Ritter Donald G. , Calisher Charles H. , Muth David J. , Shope Robert E. , Murphy Frederick A. , Whitfield Sylvia G.
Published: April 2010

Three strains of a virus were isolated from Haemaphysalis leporis-palustris (Packard) ticks removed from snowshoe hares (Lepus americanus Erxleben) in east central Alaska. We suggest that the virus be named New Minto for the location in which the ticks were collected. Prototype New Minto virus is sensitive to the action of sodium deoxycholate and kills suckling mice by the intracerebral but not intraperitoneal route; weaned mice do not die after intracerebral, intraperitoneal, or subcutaneous inoculation. The virus produces plaque in serially propagated Vero but not in primary Pekin duck embryo cells.By complement-fixation and neutralization tests New Minto is related to Sawgrass virus, a hitherto ungrouped virus from Florida. The establishment of a Sawgrass group is suggested. In addition, Sawgrass virus was found by electron microscopy to belong to the Family Rhabdoviridae.
Intracellular levels of guanosine 5′-diphosphate 3′-diphosphate (ppGpp) and guanosine 5′-triphosphate 3′-diphosphate (pppGpp) in cultures of Streptomyces griseus producing streptomycin
Authors: An G. , Vining L. C.
Published: April 2010

Guanosine 5′-diphosphate 3′-diphosphate (ppGpp) and guanosine 5′-triphosphate 3′-diphosphate (pppGpp) were identified in the vegetative mycelium of Streptomyces griseus. Adenosine 5′-diphosphate 3′-diphosphate (ppApp) and adenosine 5′-triphosphate 3′-diphosphate (pppApp) were not present but several other phosphorus-containing compounds which may have been inorganic polyphosphates were detected. During exponential growth of S. griseus the concentrations of ppGpp and pppGpp were several times higher than in the stationary stage. They fell sharply when exponential growth ended and then remained at an almost constant basal level. For the tetraphosphate the maximum concentration was about 50, and for the basal level about 10, pmol per millilitre of a culture with an optical density of 1.0. Production of streptomycin started several hours after exponential growth had ended and the concentrations of ppGpp and pppGpp had fallen. Streptomycin synthesis was delayed if the cells were resuspended just before production started in fresh medium lacking phosphate, but it was not delayed by glucose starvation. Both cultures, as well as cultures transferred to nitrogen-free medium, showed an immediate increase in ppGpp content to about four-fold the basal level. The results suggest that the guanosine polyphosphates do not directly control initiation of streptomycin production in S. griseus. Twelve additional species of Streptomyces examined all contained ppGpp and pppGpp.
β-D-phosphogalactoside galactohydrolase of Streptococcus faecalis and the inhibition of its synthesis by glucose
Authors: Heller K. , Röschenthaler R.
Published: April 2010

The lactose hydrolysing system of Streptococcus faecalis is described. It is closely related to that one of the group N streptococci as it consists of a β-D-phosphogalactoside galactohydrolase β-Pgal). The uptake of methyl-β-D-thiogalactoside (TMG), lactose, and glucose is maintained by the phosphoenolpyruvate-dependent phosphotransferase system (PTS) but the uptake of galactose is not. The induction time is 6–7 min. Inducers are lactose and galactose but not isopropyl-β-D-galactoside (IPTG) and TMG. In the presence of glucose, mannose, and maltose no induction of β-Pgal occurs but pyruvate and glycerol allow induction. The competitive inhibition of uptake of TMG by glucose suggests inducer exclusion by this sugar. TMG accumulates in the cells exclusively as a derivative.
Enumeration of petroleum-degrading marine and estuarine microorganisms by the most probable number method
Authors: Mills A. L. , Breuil C. , Colwell R. R.
Published: April 2010

Several media designed for use in a most probable number (MPN) determination of petroleum-degrading microorganisms were compared. The best results, i.e., largest numbers, were obtained using a buffered (32 mM PO4≡) liquid medium containing 1% hydrocarbon substrate. Of 104 presumptive oil degraders tested, 20 grew on oil agar medium but did not utilize oil or a mixture of pure paraffinic hydrocarbons (C10 to C16n-alkanes) in liquid (MPN) medium. Visible turbidity in the liquid medium was correlated with hydrocarbon utilization. Counts of petroleum degraders obtained using liquid medium (MPN) were in most cases higher than those obtained on an oil-amended silica gel medium. Both procedures yield an estimation of oil degraders, and the oil-amended agar permits growth of organisms which do not degrade crude oil. All strains of oil-degrading microorganisms examined in this study were lipolytic, but the converse was not always true.
Further characterization of Listeria monocytogenes serotype 5
Authors: Cooper Ronda F. , Dennis Stanley M.
Published: April 2010

Fifteen strains of Listeria monocytogenes serotype 5 were characterized for carbohydrate utilization, enzymic reactions, and other differential criteria. Hemolytic patterns were tested on ovine, bovine, equine, human, and lapine blood agars. Results were compared with those of previously reported strains of L. monocytogenes serotype 5.
Effect of sunlight on bacterial survival in transparent air samplers
Authors: Fedorak P. M. , Westlake D. W. S.
Published: April 2010

Two types of commercially available microbiological air samplers (model STA-203, New Brunswick Scientific and All-Glass Impingers, Millipore) were used outdoors at an activated sludge treatment plant. The recovery of viable particles with both instruments was increased three- to eight-fold by shielding the trapping medium from the sun during the sampling process.
Evolution of ethylene by Saccharomyces cerevisiae as influenced by the carbon source for growth and the presence of air
Authors: Thomas K. C. , Spencer Mary
Published: April 2010

Effects of the carbon source and oxygen on ethylene production by the yeast Saccharomyces cerevisiae have been studied. The amounts of ethylene evolved by the yeast culture were less than those detected in the blank (an equal volume of uninoculated medium), suggesting a net absorption of ethylene by the yeast cells. Addition of glucose to the lactate-grown yeast culture induced ethylene production. This glucose-induced stimulation of ethylene production was inhibited to a great extent by cycloheximide. Results suggested that the yeast cells in the presence of glucose synthesized an ethylene precursor and passed it into the medium. The conversion of this precursor to ethylene might be stimulated by oxygen. The fact that ethylene was produced by the yeast growing anaerobically and also by respiration-deficient mutants isolated from the wild-type yeast suggested that mitochondrial ATP synthesis was not an absolute requirement for ethylene biogenesis.
Biological nitrogen fixation in the terrestrial environment of a high Arctic ecosystem (Truelove Lowland, Devon Island, N.W.T.)
Authors: Jordan D. C. , McNicol Patricia J. , Marshall Margaret R.
Published: April 2010

Arranged in descending order of nitrogen-fixing (acetylene-reducing) potential the sites examined were mesic meadow and peat polygon troughs (equal rank), transition zone between mesic meadow and gravel ridge, gravel ridge, polar dessert, and peat polygon tops. The dominant nitrogen-fixing microorganisms, as in other Arctic areas, were blue-green bacteria, especially those epiphytic on Arctic mosses. The epiphytic association exhibited an optimum temperature for fixation of 20 °C. Other bacteria potentially able to fix nitrogen were present in the soils examined but their activity was severely restricted by low soil temperatures and lack of readily utilizable energy sources. These bacteria included members of the genera Klebsiella (the most numerous), Bacillus, Clostridium, and Beijerinckia (scarce). Also present at many of the sites was an unidentified yellow-pigmented fixer which was not Mycobacterium flavum. All fixers were psychrotrophic rather than psychrophilic, having an optimum temperature greater than 20 °C but capable of slow growth at 5 °C or lower. The rate of acetylene reduction by the epiphytic system increased with the number of successive exposures to acetylene, a phenomenon of some significance in any calculations designed to measure the amount of nitrogen fixed in certain ecosystems.
Etude physiologique et taxonomique du genre Alcaligenes: A. denitrificans, A. odorans et A. faecalis
Authors: Pichinoty F. , Véron M. , Mandel M. , Durand M. , Job C. , Garcia J.-L.
Published: April 2010

We have studied 43 strains of the species Alcaligenes denitrificans, A. odorans, and A. faecalis. Twenty-five of them were isolated by enrichment culture on minimal medium containing an organic acid (L-malate, succinate, tartrate, adipate, or itaconate) and N2O as a respiratory electron acceptor. These constitute a single phenon with the A. denitrificans strain type and 9 other strains isolated from clinical specimens. However, strain 4 differs from the other 34 strains in 12 nutritional characters, in its ability to effect a meta cleavage of diphenols, and by the absence of tetrathionate reductase. The percentages of G + C are the following: strains isolated from soil, 66.4 ± 1.1; collection strains, 67.0 ± 1.3. The 5 strains of A. odorans differ from the 34 strains of A. denitrificans (not including strain 4) in their inability to denitrify nitrate and use D-saccharate, adipate, pimelate, suberate, β-hydroxy-β-methylglutarate, meso-tartrate, azelate, and itaconate. Their percentage of G + C is much lower: 56.1 ± 0.4. From the nutritional point of view the 3 strains of A. faecalis resemble A. denitrificans. However, they differ from the latter by their inability to grow anaerobically on NO3−, NO2−, N2O, and S4O62−, and by a slightly lower percentage of G + C: 64.3 ± 0.0. The 43 strains synthesize poly-β-hydroxybutyric acid. None of them is chemolithotrophic.
Denitrification in Rhizobium
Authors: Zablotowicz R. M. , Eskew D. L. , Focht D. D.
Published: April 2010

Thirty-three strains of Rhizobium were examined for their reduction of nitrate under anoxic conditions. Three patterns of dissimilatory nitrate reduction were observed: (1) reduction to N2O and N2 (denitrification), (2) reduction to and subsequent accumulation of NO2− (nitrate respiration), (3) no reduction. Strains of R. japonicum and the cowpea miscellany displayed all three types, while strains of R. leguminosarum, R. phaseoli, and R. trifolii did not reduce nitrate by dissimilatory means. The production and subsequent metabolism of N2O was considerably different among the denitrifying strains: in some instances, N2O was a transient intermediate, while in others, it continued to accumulate during the incubation period.
Schizophyllum commune Fr. as a destructive mycoparasite
Authors: Tzean S. S. , Estey R. H.
Published: April 2010

Schizophyllum commune Fr. was shown, by light, scanning, and transmission electron microscopy, to be a destructive mycoparasite on several phytopathogenic and nematode-trapping fungi. The hyphae of S. commune coiled around host hyphae and fruiting structures and penetrated them by means of either unspecialized hyphae or by penetration pegs that developed from terminal appressoria. The host cell walls were usually chemically degraded after which the parasite grew through an electron-dense, papillate, reaction region and its underlying membrane(s) to produce trophic hyphae inside the host cells.
Role of lectins in plant–microorganism interactions. IV. Ultrastructural localization of soybean lectin binding sites on Rhizobium japonicum
Authors: Calvert H. E. , Lalonde M. , Bhuvaneswari T. V. , Bauer W. D.
Published: April 2010

The binding of purified, ferritin-labeled soybean seed lectin to the cell surfaces of Rhizobium japonicum 311b 138 has been examined by whole mount, thin section, and freeze-etch electron microscopy. The ferritin-labeled lectin binds in a biochemically specific manner to the capsular material of this bacterium. The lectin does not bind to the outer membranes of the cells or to flagella. Labeled lectin binds to sites throughout the capsular structure, although the density of labeling is somewhat greater on the outer surface of the capsule. Some cells appear to be partially encapsulated. Preservation of the capsular material proved difficult, and methods for retaining most of the capsular material were developed.
Possible association of granulocyte mobilization to the peritoneal cavity with ZnCl2-induced protection against endotoxin
Authors: Walker Richard I. , Snyder Stephen L. , Sobocinski Philip Z. , McCarthy Kenneth F. , Egan June E.
Published: April 2010

We have attempted to determine which components of the inflammatory response are responsible for ZnCl2-induced retention of endotoxin in the peritoneal cavity and enhancement of survival following challenge with the toxin. ZnCl2 injected intraperitoneally into mice caused accumulation of granulocytes in the peritoneal cavity, but these cells were apparently not responsible for the trapping process. This contention is supported by our observation that reduction of hepatosplenic uptake of 51Cr-labeled endotoxin was similar in unirradiated mice and in mice made leukopenic by irradiation (1000 rad 60Co) 1 rad = 10−2 J/kg). Hepatosplenic uptake was also depressed when untreated mice were injected with endotoxin suspended in cell-free plasma. Furthermore, zinc did not protect irradiated mice challenged with endotoxin, although it enhanced survival in unirradiated animals. Lack of protection in irradiated mice may be due to a deficiency in the cellular response in the peritoneal cavity.
The transport of microbial biomass and suspended material in a high-marsh creek
Authors: Erkenbrecher Jr. Carl W. , Stevenson L. Harold
Published: April 2010

The transport of microbial biomass and suspended material in a high-marsh creek was investigated during four 40-h tidal studies throughout the year. Although considerable differences were noted between successive tidal cycles, overall the creek was found to be an exporting system and transported a mean concentration of ATP (−33 g), chlorophyll a (−68 g), particulate organic carbon (−31 kg), total suspended material (−344 kg), and fixed suspended material (−195 kg) during each tidal cycle. This net outward flux of materials was associated with a net flow of water out of the creek, while the net import of aerobic, heterotrophic bacteria (43 × 1012) and volatile suspended material (238 kg) was generally due to higher mean concentrations of these materials per unit volume of water during the flooding tide. Also the latter generally were associated with increased amounts of suspended material suggesting an association between bacteria and suspended matter.
Comparative virulence and immunodiffusion analysis of Petriellidium boydii (Shear) Malloch strains isolated from feedlot manure and a human mycetoma
Authors: Bell R. G.
Published: April 2010

The virulence to mice of a Petriellidium boydii strain isolated from feedlot manure was compared with that of a strain from a human mycetoma. Washed spores suspended in 5% hog gastric mucin were injected intraperitoneally into non-inbred female albino Swiss mice. In 21 days, the mycetoma strain killed 95% of the test animals whereas injection of eight times as many feedlot strain spores resulted in only 28% mortality. A progressive, exclusively sinistral (left-sided) torticollis was the most obvious symptom of experimental petriellidiosis. Mycelia bearing annellospores were observed in PAS-stained sections of most internal organs, including the brains, of the test animals. Immunodiffusion analyses were conducted on soluble antigen preparations with concentrated antisera produced in rabbits using live spore suspensions. The two strains-contained common antigens but the proportions of two were significantly different.
Characteristics of PR5, a lipid-containing plasmid-dependent phage
Authors: Wong F. H. , Bryan L. E.
Published: April 2010

An extensive characterization of plasmid-dependent phage PR5 isolated from sewage has been carried out. The phage has a head diameter of 65–68 nm, is isometric with a double-layered capsid, and a minority possess tails. It adsorbs to many but not all types of bacteria possessing P, N, or W plasmids. The phage contains 20% lipid, 15.1% DNA, and 64.9% protein by weight and has a buoyant density of 1.265 g/ml in CsCl. The DNA is double-stranded with a G + C content of 49% and a molecular weight of 7.4 ± 0.6 × 106 as shown by electron microscopy. Phospholipid content is 66% of the lipid and consists of cardiolipin (13%), phosphatidylethanolamine (43%), and phosphatidylglycerol (44%) and differs quantitatively from that of host bacteria. Anti-PR5 serum inactivates other similar phages, PR3 and PR4. Phage adsorption is impaired in deep rough mutants of Salmonella minnesota.
Spiroplasma associated with flowers of the tulip tree (Liriodendron tulipifera L.)
Authors: Davis Robert E.
Published: April 2010

Spiroplasmas were isolated and cultivated from nonsurface-sterilized petals and bracts excised from flowers of Liriodendron tulipifera L. (tulip tree) in Anne Arundel, Charles, and Prince George's Counties in Maryland, and East Lyme County, Connecticut. All isolates grew at 30 and at 37 °C. Morphology of colonies on solid agar (1%) medium containing serum differed among isolates: some isolates formed highly diffuse, barely visible colonies; others formed distinct colonies with granular centers surrounded by minute surface or submerged 'satellite' colonies. Cellular morphology and motility of organisms in broth and in agar culture were typical of the spiroplasmas pathogenic in plants and insects. In viscous media containing methylcellulose, spiroplasmas freely suspended in the medium swam, and organisms in contact with glass slide or coverslip "crawled" across the solid surface. Growth inhibition, metabolic inhibition, and organism deformation tests failed to reveal a serologic relationship between spiroplasma strain 23-6 from tulip tree flowers and spiroplasma strain AS 576 from honey bee.
Partial characterization of a cubic Bacillus phage
Authors: Ackermann H.-W. , Roy R. , Martin M. , Murthy M. R. V. , Smirnoff W. A.
Published: April 2010

Phage Bam35 is an icosahedron of about 63 nm in diameter. It has a double capsid with spikes at the vertices, and a tail which seems to appear upon nucleic acid ejection. The phage contains DNA and, probably, lipids which seem to be located in the inner coat. The phage is Bacillus-specific, UV- and lipase-resistant, and sensitive to heat, chloroform, and ether. The latent period is 50 min and the burst size is 39. Phage Bam35 belongs to a new virus group which includes a phage of B. anthracis and four phages of gram-negative bacteria harboring drug-resistance plasmids.
Interspecies matings of Streptomyces fradiae with Streptomyces bikiniensis mediated by conventional and protoplast fusion techniques
Authors: Godfrey O. , Ford L. , Huber M. L. B.
Published: April 2010

A genetic recombination system for an interspecies mating of Streptomyces bikiniensis with Streptomyces fradiae is demonstrated both by conventional and protoplast fusion methods.
Purification and properties of amylase produced by a moderately halophilic Acinetobacter sp.
Authors: Onishi Hiroshi , Hidaka Osamu
Published: April 2010

A moderately halophilic Acinetobacter sp., capable of producing dextrinogenic amylase, was isolated from sea-sands. Maximum enzyme production was obtained when the bacterium was cultivated aerobically in media containing 1 to 2 M NaCl or 1 M KCl. Two kinds of amylase, amylases I and II were purified from the culture filtrate to an electrophoretically homogenous state by glycogen-complex formation, DEAE-Sephadex A-50 chromatography, and Sephadex G-200 gel filtration. Both enzymes had maximal activity at pH 7.0 in 0.2 to 0.6 M NaCl or KCl at 50 to 55 °C. The activities were lost by dialysis against distilled water. Molecular weights for amylases I and II were estimated to be 55 000 and 65 000 respectively by SDS-gel electrophoresis. The action pattern on amylose, soluble starch, and glycogen showed that the products were maltose and maltotriose.
The production of toxic metabolites by Chaetomium spp. isolated from soils of permanent pasture
Authors: Brewer D. , Taylor A.
Published: April 2010

One hundred and two isolates of Chaetomium spp. have been identified from 2563 soil samples collected from permanent pasture at Nappan, Nova Scotia. Chaetomium umbonatum was the Chaetomium species most commonly isolated. Fifty-six of the Chaetomium isolates were grown in the laboratory and the cultures examined for the production of toxic metabolites. The culture filtrates of 12, and extracts of mycelium of 18, of these isolates inhibited bacterial growth. Chetomin was detected in nine mycelium extracts and isolated from four of the mycelium extracts. Chaetoglobosins were isolated from three mycelium extracts.
Microbes associated with the epithelium of the oesophagus and stomach of guinea pigs (Cavia porcellus)
Authors: Yoon Chong Siew , Tannock Gerald W.
Published: April 2010

Histological examination of oesophagus and stomach specimens from 28 guinea pigs (Cavia porcellus) revealed microbes associated with the epithelial surface of these organs. Layers of Gram-positive cocci were associated with oesophageal tissue in all the animals. Yeasts(Torulopsis pintolopesii) were associated with stomach tissue in most animals 1 week of age or older.
Fungal exudates
Authors: Colotelo Nicholas
Published: April 2010

The exudates or liquid droplets on various structures of a number of fungi were examined. The droplets were enveloped in membranous material and were associated with actively growing mycelia, including fruiting structures. Osmium tetroxide vapour-fixed droplets of Claviceps purpurea, Myrothecium roridum, Sclerotinia sclerotiorum, Sclerotium rolfsii, and Thanathephorus cucumeris did not dry to a powder but remained intact as spheres when freeze-dried. Fractured spheres, examined with the scanning electron microscope, showed the presence of a membranous structure similar to that of rapidly frozen colloidal solutions with the ice crystals removed by sublimation. Locules or cavities within the freeze-dried droplets are thought to be due to the entrapment of air when droplets coalesce. Biochemical analyses of the exudates showed that acid phosphatase, β-glucosidase, acid and alkaline protease, RNase polygalacturonase and cellulase enzymes as well as oxalic acid and ammonia were present.
The growth of Mycobacterium convolutum on solid n-alkane substrates: effect on cellular lipid composition
Authors: Hallas L. E. , Vestal J. Robie
Published: April 2010

Growth rates and cell yields of Mycobacterium convolutum strain R22 grown on a wide range of both odd- and even-numbered carbon solid n-alkanes decreased as the substrate carbon number increased. Cellular lipid was 2.5 times higher following growth on the hydrocarbon substrates. The amount of polar lipid was found to be about half of the cellular lipid in docosane through octacosane-grown cells. Phosphatidylethanolamine represented about 50% of the polar phospholipid in hydrocarbon- and nonhydrocarbon-grown cells. Phosphatidylserine, diphosphatidylglycerol, and phosphatidic acid were also found. The amount of phosphatidylserine was higher (10–14%) in docosane through octacosane-grown cells. There was a correspondingly smaller amount of diphosphatidylglycerol. These lipid changes may be associated with the assimilation of the hydrophobic substrates. The failure to detect label in lipids of solid n-alkane-grown cells incubated in the presence of [14C]acetate suggested that de novo synthesis of fatty acids did not occur to an appreciable extent. Transport of [14C]acetate and incorporation into cellular protein was not inhibited. Polar lipid fatty acid analyses indicated there was no direct incorporation of the oxidized substrate. The results suggest that β-oxidation and a subterminal oxidative cleavage appear to be the major catabolic routes providing fatty acids, which are then incorporated into lipid.
Relative microbial activity and bacterial concentrations in water and sediment samples taken in the Beaufort Sea
Authors: Griffiths Robert P. , Hayasaka Steven S. , McNamara Thomas M. , Morita Richard Y.
Published: April 2010

A total of 91 water, 8 ice, and 50 sediment samples taken from the southwestern Beaufort Sea were analyzed for relative microbial activity, bacterial cell concentrations, and percentage of respiration (mineralization). These samples were taken during three field-study periods (August to September 1975; April 1976; and August 1976). Both the relative microbial activity and the cell concentrations in water and sediment samples were lower during the April (winter) sampling period than in the August–September (summer) studies. The percentage of respiration of labeled glutamic acid was higher in the winter water samples than in the summer samples. The water samples showed higher percentage of respiration values than did sediment samples. The average maximimum potential rate of glutamic acid uptake was as high or higher than those observed in studies made in more temperate waters. Samples of melted sea ice showed levels of relative microbial activity that were about the same as that found in the associated seawater. When 1:1 mixtures of melted ice and seawater were analyzed for altered microbial activity, little effect could be detected.
Endotoxic activity of cell-free rumen fluid from cattle fed hay or grain
Authors: Nagaraja T. G. , Fina L. R. , Bartley E. E. , Anthony H. D.
Published: April 2010

The cell-free rumen fluid from cattle fed hay or grain exhibited the following biological characteristics which strongly suggest the presence of endotoxin or a toxic principle similar to endotoxin of gram-negative bacteria: proved lethal to mice when injected with actinomycin D; proved extremely lethal to chick embryos: induced biphasic pyrogenic response in rabbits; enhanced susceptibility to bacterial infection in mice; evoked positive epinephrine skin reaction in rabbits and phenol–water or aqueous ether extract proved lethal to mice and chick embryos. A quantitative difference in concentrations of endotoxin was observed, based on LD50 in mice and chick embryos and response to the epinephrine skin test in rabbits. Cell-free rumen fluid of grain-fed cattle contained at least twice as much endotoxin as that of hay-fed cattle. Endotoxin in cell-free rumen fluid and in higher concentration in cattle fed grain than in those fed hay support the hypothesis that rumen bacterial endotoxins may participate in the pathogenesis of diseases associated with high grain feeding such as lactic acidosis and the sudden-death syndrome.
Temperature-induced differences in growth rate and fatty acid composition in two strains of Escherichia coli 15T−
Authors: Crowe John L. , Urban James E.
Published: April 2010

The saturated/unsaturated fatty acid ratio of Escherichia coli 15T− decreases almost threefold as growth temperature decreases from 43 to 27 °C, whereas the ratio of a fast-growing mutant derived from 15T− changes only half as much. Strain 15T− experiences a 2.4-fold change in doubling time across this temperature range, but doubling time in the mutant changes 3.3-fold.
Studies on bacteroid size and nucleic acid content of alfalfa bacteroids fractionated by velocity sedimentation
Authors: Paau Alan S. , Cowles Joe R.
Published: April 2010

A velocity sedimentation procedure was described to fractionate bacteroids of alfalfa nodules into four subpopulations. Bacteroids in these subpopulations were different in size and nucleic acid content as determined by microscopy and flow-microfluorbmetry (FMF). The slowest-sedimenting bacteroids (fraction I) were small and resembled free-living Rhizobium meliloti both in size and nucleic acid content. The fastest-sedimenting bacteroids (fraction IV) were 2 to 3 times longer and contained 3 to 4 times more nucleic acid than the small bacteroids in fraction I and free-living R. meliloti. A positive correlation was established between bacteroid size and relative nucleic acid content of bacteroids in alfalfa nodules.
Cyst and germ tube wall structure in Aphanomyces astaci, Oomycetes
Authors: Nyhlén Lars , Unestam Torgny
Published: April 2010

Aphanomyces astaci secondary cyst walls and walls of germinating spores were prepared by alkaline hydrolysis, autolysis, sonication, and enzymic degradation and were examined by shadow-casting and negative-staining techniques. The cyst wall consists of randomly oriented fibrils, about 3 nm in diameter. The fibrils are embedded in, or covered by, amorphous β-1,3-glucans which can easily be removed by alkaline hydrolysis. The germ tube wall surface has the same structure, but the amorphous layer is less easily removed.
Activité antimicrobienne d'antioxydants phénoliques
Authors: Turcotte Pierre , Saheb Samir A.
Published: April 2010

The antimicrobial activity of three antioxydants, butylated hydroxytoluene (BHT), butylated hydroxyanisole (BHA) and ethoxyquin (ETO) was studied. In vitro assays showed that when these antioxydants are added to the culture media at concentrations lower or equal to that used in nutrition, they inhibit or decrease the growth of certain microorganisms. BHT showed the most marked effect, affecting Gram-positive bacteria at a higher degree than the Gram-negative bacteria belonging to the family Enterobacteriaceae. Inactivation study of different bacterial species by BHT revealed differences in sensitivity among a single genus and between strains of the same species. The association of ETO with BHT results in an increase of the inhibitory activity. The increased sensitivity to BHT resulting from the osmotic shock of Escherichia coli cells suggests that the resistance to BHT of the Gram-negative bacteria belonging to the family Enterobacteriaceae might be due in part to the structure of their cell wall.
Further taxonomic characterization of the genus Bdellovibrio
Authors: Torrella Francisco , Guerrero Richard , Seidler Ramon J.
Published: April 2010

Cultures of Bdellovibrio isolated from different geographic locations have been studied in terms of deoxyribonucleic acid analysis (% G + C, genome size, and DNA hybridization), cytochrome spectrum, and host range. Isolates of the genus exhibit a broad range of % G + C ranging from 37 to 51% and the genome sizes extend from 1300 × 106 to 1700 × 106 daltons. DNA hybridization continues to reveal a high level of genetic heterogeneity. Bdellovibrio 3294 exhibits 32% relative reassociation to Bdellovibrio W, 37% to Bdellovibrio stolpii Uki2, and an undetectible level to Bdellovibrio starrii A3.12. Bdellovibrio W is 23% related to B. starrii A3.12 and 28.5%to B. stolpii Uki2. For the first time differential absorption techniques have revealed peaks of cytochrome b. The analysis of the cytochrome spectrum seems to be limited as a taxonomic tool since most of the recent isolates studied share a common cytochrome spectrum. Host-range studies have been found to be dependent on the experimental conditions, and with the exception of one isolate (B. starrii A3.12) the taxonomic significance of such techniques must be taken with caution.