bluuebunny/crossref_metadata_2025 huggingface dataset:
Adenovirus core proteins
Authors: Weber Joseph M. , Khittoo Govindranathsing , Bhatti A. Rashid
Published: May 2010

Advenovirus type 2 core proteins were studied with the aid of temperature-sensitive (ts) mutants affecting them. Cores prepared from wild-type virions with pyridine contained the structural proteins IVa2, V, VII, and X. Cores from the H2ts3 mutant contained an altered polypeptide V (50 K) of higher molecular weight and additional peptides. Ts1 virions produced at the restrictive temperature contained precores with proteins IVa2, V, pre-VI, pre-VII, and 11 K. This precore could be matured to a wild-type-like core by the adenovirus endoprotease. Of these core proteins only V, pre-VI, pre-VII, VII, and 11 K could be shown to reassociate in vitro with double-stranded heterologous DNA. Proteins IVa2 and X may bind to these core proteins rather than to the DNA directly.
Partial purification and properties of an L-arabinose dehydrogenase from Azospirillum brasiliense
Authors: Novick Norman J. , Tyler Max E.
Published: May 2010

An L-arabino-aldose dehydrogenase responsible for the oxidation of L-arabinose to L-arabino-γ-lactone has been purified 59-fold from L-arabinose grown cells of Azospirillum brasiliense. The dehydrogenase was found to be specific for substrates with the L-arabino-configuration at carbons 2, 3, and 4. Km values for L-arabinose of 75 and 140 μM were found with NADP and NAD as coenzymes, respectively. The enzyme had a pH optimum of 9.5 in glycine buffer and was stable when heated to 55 °C for 5 min. No enhancement of activity in the presence of any divalent cation or reducing agent tested was found. L-Arabinose dehydrogenase had a molecular weight of 175 000 as measured by the gel filtration technique.
Nutritional requirements for chloramphenicol biosynthesis in Streptomyces venezuelae
Authors: Chatterjee S. , Vining L. C. , Westlake D. W. S.
Published: May 2010

Cultures grown in a glycerol serine lactate medium were used to establish the inoculation procedure, aeration level, and trace-mineral nutrition optimizing chloramphenicol production in Streptomyces venezuelae. The stimulatory effect of lactate in this medium was concluded not to be an artifact of medium preparation but to reside in its influence on carbon-source utilization. In media with ammonium sulfate as a nonrestricting source of nitrogen, chloramphenicol production varied with the carbon source chosen. Production occurred during the growth phase and was highest on galactose, lactose, cellobiose, and starch. The rate of synthesis was related directed to the growth rate and decreased in the stationary phase. Variation of the nitrogen source with glucose as a nonrestricting source of carbon showed that the highest antibiotic titres were obtained with poorly utilized compounds such as isoleucine or phenylalanine. Proline gave yields comparable with those obtained in the more complex glycerol serine lactate medium in a shorter time. Although rate of growth is not the sole determining parameter, chloramphenicol synthesis is concluded to be a "growth-linked" process.
The effects of chlorinated municipal sewage and temperature on the abundance of bacteria in the Sheep River, Alberta
Authors: Osborne L. L. , Davies R. W. , Ventullo R. M. , Ladd T. I. , Costerton J. W.
Published: May 2010

The intersite and temporal differences in the abundance of sessile and planktonic bacteria subjected to a chlorinated municipal sewage discharge and a thermal discharge were investigated in the Sheep River, Alberta, from January through December 1978. Significantly higher densities of both sessile and planktonic cells generally occurred within the chlorinated effluent plume. Higher numbers of sessile bacteria were also found below the thermal discharge, with maximum densities occurring in the late winter – early spring and minimum densities following mountain runoff. The higher numbers of sessile bacteria in the chlorinated plume was attributed to nutrient enrichment. These results indicate that chlorinated sewage effluent has no adverse effects on the abundance of sessile bacteria.
Alkaline extraction of toxin from spores of the mosquito pathogen, Bacillus sphaericus strain 1593
Authors: Davidson Elizabeth West
Published: May 2010

Toxin was extracted from spores of the mosquito pathogen Bacillus sphaericus strain 1593 using 0.05 M NaOH. The molecular weight of this toxin was 35 000–54 000. Toxic activity of this extract was resistant to a variety of enzymes including subtilisin, but was degraded by pronase. Antiserum produced to 1593 spore toxin neutralized spore toxin and cytoplasmic toxin activity, but did not react with Bacillus thuringiensis var. israelensis crystal toxin, nor did var. israelensis toxin antiserum react with B. sphaericus toxin. Crystallike parasporal inclusions accompanying the B. sphaericus 1593 spores were removed by NaOH extraction.
Production of phenylacetic acid by Bacteroides melaninogenicus ssp. intermedius serogroup C-1
Authors: Ferguson Kaethe P. , Mayberry William R. , Lambe Jr. Dwight W.
Published: May 2010

The methyl derivatives of broth cultures of black-pigmented Bacteroides were examined by gas chromatography for production of phenylacetic acid. Two serogroups of B. melaninogenicus ssp. intermedius described by Lambe differed in the ability to produce phenylacetate. Serogroup C failed to produce phenylacetic acid while serogroup C-1 produced small amounts of phenylacetate, which contributed 2.2–5.7% to the total nonvolatile acid profile. Holdeman's newly proposed species "B. intermedius" and "B. corporis" correspond to serogroups C and C-1, respectively. These data support the elevation of the two serogroups of B. melaninogenicus ssp. intermedius to species status. Bacteroides gingivalis produced phenylacetate in significantly larger quantities than B. corporis. Bacteroides melaninogenicus ssp. melaninogenicus, "B. melaninogenicus ssp. levii," and B. asaccharolyticus did not produce phenylacetic acid. These results indicate that phenylacetic acid production may be useful in distinguishing "B. corporis" and B. gingivalis from the other black-pigmented Bacteroides.
The effect of 2,4-dinitrophenol on glycerol-limited, biphasic growth of Gluconobacter oxydans
Authors: Batzing Barry L. , Dellork Richard
Published: May 2010

2,4-Dinitrophenol specifically inhibited the secondary phase of biphasic growth when Gluconobacter oxydans was grown on a glycerol-limiting medium. Addition of glycerol to cultures under the inhibitory effect of 2,4-dinitrophenol resulted in immediate escape from inhibition.
Microbial degradation of organic sulfur compounds in Prudhoe Bay crude oil
Authors: Fedorak P. M. , Westlake D. W. S.
Published: May 2010

Water samples from three different marine environments in Washington State were challenged with Prudhoe Bay crude oil and incubated at 8 °C with aeration. Some cultures were supplemented with NH4NO3 and phosphate and after various lengths of time, up to 27 days, the residual oil was extracted and fractionated using silica gel columns. The aromatic fraction was analyzed by capillary gas chromatography using a sulfur-specific flame photometric detector. The oil contained alkylbenzo[b]thiophenes, dibenzothiophene, and C1- and C2-dibenzothiophenes and the degradation of these was monitored. Many of the sulfur heterocycles were metabolized without nutrient supplementation although the number and extent of the compounds degraded increased with nutrient addition. The order of susceptibility of the sulfur heterocycles in homologous series was found to be the following: C2-benzo[b]thiophenes > C3-benzothiophenes; dibenzothiophene > C1-dibenzothiophenes > C2-dibenzothiophenes. With nutrient supplementation, the microbial population from a harbor area metabolized the sulfur compounds more readily than those from near an oil tanker dock or from a pristine state park beach. Without supplementation, the population from the tanker dock area degraded many fewer sulfur heterocycles than the other two populations.
Gallionella from metalimnion in an eutrophic lake: morphology and X-ray energy-dispersive microanalysis of apical cells and stalks
Authors: Heldal Mikal , Tumyr Ole
Published: May 2010

The genus Gallionella constitutes a major microbial population in the metalimnion of an eutrophic lake. The normal morphology of this pelagic community is spherical to rod-shaped apical cells on fibrillar, nontwisted, dichotomously branching stalks. X-ray energy-dispersive microanalysis of stalks and apical cells established that the stalks do not contain phosphorus and are thus unlikely to represent living cellular material. Iron in the stalks forms a gradient, the lowest concentration being found proximal to the apical cells and highest concentration in the distal end of the stalk.
Characterization of a brown pigment from Bacillus subtilis cultures
Authors: Barnett Terry A. , Hageman James H.
Published: May 2010

Bacillus subtilis cells produce brown pigments upon sporulation in liquid or solid medium, a phenotypic trait often made use of in genetic studies. One of five brown pigments produced in a defined liquid medium, designated pigment T1, has been purified to homogeneity by gel permeation chromatography, butanol extraction, and absorption chromatography on microcrystalline cellulose and silica gel. The molecular weight of pigment T1 was estimated to be 3500. The pigment has a featureless visible absorption spectrum (absorbance increases logarithmically with decreasing wavelength) and a shoulder in the ultraviolet absorption spectrum at 260 nm. Pigment T1 exhibited a yellow fluorescence; the excitation maximum was 292 nm, and the emission maximum was 367 nm. The compound was freely soluble in water, methanol, and dimethylsulfoxide, contained 1 mol of carbohydrate per 3500 g but no Mn2+ and no amino acids which could be released by acid hydrolysis. Elemental analysis of pigment T1 gave the following: C, 44.02%; H, 6.40%; N, 10.35%; O, 36.49%; and S, 2.74%, which corresponded to a simplest formula of C43H75N9O27S1. Although it had been suggested previously that the brown pigments of B. subtilis were melanins, it was concluded from the data given here that pigment T1 is not a melanin.
Gliovirin, a new antibiotic from Gliocladium virens, and its role in the biological control of Pythium ultimum
Authors: Howell Charles R. , Stipanovic Robert D.
Published: May 2010

A compound with antibiotic activity toward Pythium ultimum was isolated from potato dextrose broth shake cultures of Gliocladium virens, a common soil mycoparasite known to inhibit but not parasitize P. ultimum. The mass spectrum and an X-ray crystallograph of the purified antibiotic indicated that it was a new diketopiperazine, and we have given it the trivial name gliovirin. Gliovirin is highly toxic to P. ultimum but is inactive against other fungi associated with cotton seedling disease. The antibiotic does not persist in nonsterile soil where it is apparently inactivated by the soil microflora.An ultraviolet light induced mutant of G. virens deficient for gliovirin production was overgrown by P. ultimum in culture and did not protect cotton seedlings from damping-off in P. ultimum infested soil. A mutant with enhanced gliovirin production was more inhibitory to P. ultimum in culture than the parent isolate and showed similar efficacy as a seedling disease suppressant, even though its growth rate was reduced when compared to the parent isolate. These results indicate that gliovirin may be important to the antagonist–pathogen interaction.
Improved media for growth and sporulation of Sporidesmium sclerotivorum
Authors: Ayers William A. , Adams Peter B.
Published: May 2010

Additional nutritional and environmental factors affecting growth and sporulation of the beneficial mycoparasite, Sporidesmium sclerotivorum, were determined. A liquid medium composed of mineral salts, glucose, glutamine, thiamine, biotin, and succinic acid supported good growth and sporulation of isolate CS-5 within 5 weeks at 25 °C. Growth was substantially greater in a medium with KH2PO4, CaCl2, minor elements, and ferric–potassium salt of EDTA (FeKEDTA) than in media with single omissions of these ingredients. Iron supplied as FeCl3 or FeKEDTA at 10−5 M or greater markedly stimulated production of conidia. Supplementation of the medium with Casamino acids or with Soytone and yeast extract decreased the lag phase slightly but did not affect the maximum growth rate nor final mycelial and spore yield. Succinic acid (0.2%) buffered the medium against a rapid drop in pH and thereby promoted growth. The growth rate was independent of glucose concentrations of 0.5 to 2%, but the total mycelial yield was dependent upon the total amount of glucose furnished. Conidia developed primarily on mycelial mat surfaces, and maximum spore yields were favored by cultivation in shallow depths of medium.
Characterization of mutants of herpes simplex viruses, types 1 and 2, that produce fragments of the thymidine kinase polypeptide
Authors: Block Timothy M. -P. , Kuhn Nancy J. , Kustas Karen A. , Held William A. , Gross Kenneth , Hughes Jr. Robert G.
Published: May 2010

Seven tk− mutants of herpes simplex virus, type 2 (HSV-2), and three tk− mutants of herpes simplex virus, type 1 (HSV-1), were isolated which did not produce the thymidine kinase (TK) polypeptides but formed smaller polypeptides not seen in wild-type infected cells. Positive TK mRNA selection by hybridization to the cloned tk genes followed by in vitro translation identified the TK polypeptides. Comparisons of the products of partial proteolysis of the polypeptides of four HSV-2 and two HSV-1 tk− mutants to those of the parental TK polypeptides indicated that, in each case, the novel polypeptide was a fragment of the TK polypeptide, showing that these mutants have defects in the structural gene for tk. HSV-2 mutants of this sort have not been previously described. They and the HSV-1 mutants are similar to HSV-1 mutants reported previously. In addition, it was found that TK mRNA was present early in infection but was absent late in infection, suggesting that the shutoff of TK synthesis is due to message degradation. Also, HSV-2 TK mRNA did not hybridize to the cloned HSV-1 tk gene indicating that these genes have extensively diverged.
The transport and metabolism of glucose in cowpea rhizobia
Authors: Stowers Mark D. , Elkan Gerald H.
Published: May 2010

Cell-free extracts of several strains of cowpea rhizobia grown under free-living conditions were surveyed for key enzymes of carbohydrate metabolism. Enzymes of the Entner–Doudoroff (ED) and Embden–Meyerhof–Parnas (EMP) pathways were detected while 6-phosphogluconate dehydrogenase was not detected, indicating the apparent absence of the pentose phosphate (PP) pathway. Transketolase and transaldolase reactions were present, indicating a pathway for the synthesis of pyrimidines and purines from fructose-6-phosphate and glyceraldehyde-3-phosphate. Radiorespirometric analysis with specifically labelled glucose indicated that the ED pathway with the hexose cycle was the primary pathway of glucose dissimilation. The presence of isocitrate and malate dehydrogenases and results of radiorespirometric analysis with pyruvate and succinate demonstrates an operational tricarboxylic acid (TCA) cycle in glucose-grown cowpea rhizobia. The transport of glucose was inhibited by carbonyl cyanide m-chlorphenylhydrazone (CCCP), dinitrophenol, and potassium cyanide indicating that the process was active, probably using an energized membrane state. The transport of glucose was glucose specific. A lower rate of glucose uptake was seen when cells were cultured on hexoses other than glucose.
Scanning electron microscopy of mouse ciliated oviduct and tracheal epithelium infected in vitro with Bordetella pertussis
Authors: Opremcak Lauren B. , Rheins Melvin S.
Published: May 2010

Infection of mouse tracheal organ culture with Bordetella pertussis resulted in ciliostasis within 36 h. Scanning electron microscopy revealed that B. pertussis attached exclusively to ciliated cells but did not induce expulsion of this cell type at a test interval of 48 h. Mouse oviduct organ culture infected with B. pertussis demonstrated the same strict tropism for ciliated cells as in the tracheal ring system. Only ciliated cells were parasitized, becoming heavily colonized 48 h postinfection. Infected ciliated oviduct cells were not extruded. A fixation method which enhances fine structure was used in the scanning electron microscope studies. Bacterial fimbriae were not observed as the method of attachment of B. pertussis to cilia but fine fibers were seen extending between cilia and bacterial cells.
Studies on the ring-cyclization and ring-expansion enzymes of β-lactam biosynthesis in Cephalosporium acremonium
Authors: Kupka Jutta , Shen Yong-Qiang , Wolfe Saul , Demain Arnold L.
Published: May 2010

Micrococcus luteus was found to be very sensitive to isopenicillin N and was used as assay organism for purification of the enzyme isopenicillin N synthetase, which cyclizes δ-(L-α-aminoadipyl)-L-cysteinyl-D-valine to isopenicillin N. Purification of the enzyme from the crude extract obtained by sonication of mycelia of Cephalosporium acremonium CW-19 was carried out by ammonium sulfate precipitation, desalting with Sephadex G-25, gel filtration on LKB ultrogel AcA44 or ion-exchange chromatography on DEAE-Sepharose. The cyclization enzyme was separated from the ring-expansion enzyme and was purified considerably more than 50-fold by this procedure. Using the purified enzyme, we found that the disulfide bis-δ-(L-α-aminoadipyl)-L-cysteinyl-D-valine required reduction to δ-(L-α-aminoadipyl)-L-cysteinyl-D-valine in order to behave as a substrate. The enzyme activity was stimulated by FeSO4 and ascorbate, but other cofactors, including α-ketoglutarate, were inactive. In addition to δ-(L-α-aminoadipyl)-L-cysteinyl-D-valine, the enzyme converted adipyl-L-cysteinyl-D-valine, N-acetyl-δ-(L-α-aminoadipyl)-L-cysteinyl-D-valine, and glycyl-δ-(L-α-aminoadipyl) L-cysteinyl-D-valine to penicillins. All of these latter peptides were competitive inhibitors of the cyclization reaction. The Km of the cyclization enzyme is 10 times higher than that of the ring-expansion enzyme, deactoxycephalosporin C synthetase. The pH and temperature optima of the two enzymes were rather similar. Phosphate inhibited ring expansion, but not cyclization. Both enzymes appear to be soluble enzymes of about 31 000 molecular weight.
Partial characterization of the extracellular carboxymethylcellulase activity produced by the rumen bacterium Bacteroides succinogenes
Authors: Groleau D. , Forsberg C. W.
Published: May 2010

In cultures of Bacteroides succinogenes, in which cellulose was the source of carbohydrate, from 70 to 80% of the carboxymethylcellulase (CMCase) activity was present in the culture fluid. The crude extracellular enzyme readily hydrolyzed acid-swollen cellulose with the production of glucose and cellobiose. Of this extracellular CMCase, 50–62% was associated with sedimentable membrane fragments, 9–13% with nonsedimentable material with a molecular weight greater than 4 × 106, and 28–38% with molecules having a molecular weight of approximately 45 000. Polyacrylamide gel electrophoresis (PAGE), in the presence of sodium dodecyl sulfate, revealed that both the nonsedimentable and the sedimentable fraction had complex protein compositions. The nonsedimentable and sedimentable CMCase fractions, after treatment with Triton X-100, were subjected to PAGE in the presence of 0.2% (w/v) Triton X-100. The results indicated the presence of fast- and slow-migrating CMCases in the former, and of a slow-migrating CMCase in the latter. An apparently uncharged CMCase, which probably corresponded to the slow-migrating component by PAGE, was partially purified from the concentrated culture supernate by solubilization in Triton X-100 and chromatography on DEAE–Sepharose, CM–Sepharose, and Phenyl–Sepharose. The partially purified CMCase had a pH optimum of 5.6–6.6 and a temperature optimum of 50 °C.
Characterization of Rhizobium sp. (Cicer arietinum L.) by immunofluorescence, immunodiffusion, and intrinsic antibiotic resistance
Authors: Kingsley Mark T. , Bohlool B. Ben
Published: May 2010

Twenty-nine cultures of Rhizobium spp. for chickpea (Cicer arietinum L.) from various culture collections were characterized by serological techniques and by intrinsic antibiotic resistance (IAR). Fluorescent antibodies (FAs) against the somatic antigens of eight of the inoculum-quality strains grouped all cultures into at least four distinct somatic serogroups. Serogroup I (Nitragin 27A8) contained the majority of the strains. Serogroups II (Nigragin 27A3) and III (TAL-480) each crossreacted with one strain, while serogroup IV (USDA 3HOa9) consisted only of the homologous strain. Nine of the chickpea strains and 55 other cultures from among strains of R. leguminosarum, R. lupini, R. japonicum, and Rhizobium spp. (Vigna, Sesbania, and Stylosanthes) did not react with any of the four specific FAs. Immunofluorescence – cross adsorption and immunodiffusion analyses of cultures within serogroup I revealed that four of the strains most commonly recommended for inoculum use were serologically identical. The intrinsic antibiotic resistance patterns of these four cultures were also identical. Serogroup II was shown to contain two distinct serotypes (Nitragen 27A3 and 27A16), while the two strains in serogroup III (TAL 480 and 622) were found to be the same. Although intrinsic antibiotic resistance could differentiate among the strains, some cultures that were completely different by serological means were found to group in the same IAR categories. Additionally, some cultures that were serologically identical were found to have different IARs. Our data on antigenic uniqueness of the chickpea rhizobia and their lack of serological crossreaction with any other Rhizobium species (especially with those in R. leguminosarum, where they had previously been classified), as well as the results of other workers on their nodulation specificity for Cicer, led support to the proposal that C. arietinum and its root-nodule bacteria constitute a separate cross-inoculation group.
Characteristics and diversity of subarctic marine oligotrophic, stenoheterotrophic, and euryheterotrophic bacterial populations
Authors: Horowitz A. , Krichevsky M. I. , Atlas R. M.
Published: May 2010

Major differences were found in the characteristics of bacterial populations isolated on media containing high and low nutrient concentrations. Bacteria isolated on low-nutrient media were physiologically more tolerant and nutritionally more versatile than bacteria isolated on high-nutrient media. It appears that euryheterotrophy, as opposed to oligotrophy, is characteristic of subarctic marine bacterial populations capable of growing at low nutrient concentrations. The bacteria examined in this study were capable of growth under a wide variety of physiological and nutritional conditions. The isolates from high-nutrient media were somewhat more specialized than those isolated from low-nutrient media. While the physiological and metabolic capabilities of the bacterial populations isolated on low-nutrient media were very heterogeneous, their taxonomic diversity was lower than bacterial populations from high-nutrient isolation media. The inclusion of petroleum in the isolation media did not alter the characteristics of the isolates obtained from either high- or low-nutrient media.
Effect on nodulation by adaptation of Rhizobium trifolii to ammonium nitrate
Authors: Beeraj R. D.
Published: May 2010

Training on media containing increasing concentrations of ammonium nitrate resulted in an extension of the range of tolerance of Rhizobium trifolii Dangeard to this salt. Whereas ability to tolerate high levels of ammonium nitrate resulted in an improvement in growth on lower levels, passage back on ammonium nitrate-free media caused a gradual reversion to the original range of tolerance. Ability to tolerate high concentrations of ammonium nitrate was accompanied by a change to a nodulation pattern indicating ineffective symbiosis. Restoration of the original nodulating ability was only possible at the expense of high nitrogen tolerance. The nature of this response was determined as being adaptational rather than mutational.
Distribution of heterotrophic bacteria in relation to the concentration of particulate organic matter in seawater
Authors: Fukami Kimio , Simidu Usio , Taga Nobuo
Published: May 2010

The relationship between the number of bacteria and the concentration of particulate organic carbon (POC) in seawater was investigated. In coastal seawater in summer, the POC concentration showed better correlation to the density of bacteria obtained by the viable plate count method (viable count, V.C.) than by the total direct count method (total count, T.C.). The number of attached bacteria (A) showed significant fluctuation, both laterally on a geographical scale and vertically in the water column; on the other hand, the number of free-living bacteria (F) was relatively constant. The POC concentration had a much higher correlation with A (r = 0.8795) than with T.C. (r = 0.7339), and had a low correlation with F (r = 0.6935). Moreover, a very good correlation was observed between the density of bacteria obtained by V.C. and A (r = 0.9153). These results indicate that when the concentration of particulate organic matter (POM) increases, some free-living bacteria become attached to POM, and grow on the surface of POM. These communities of attached bacteria have the ability to make colonies on plate media and can be counted as the "viable plate count."
Effects of passaging through scarabeid hosts on virulence and host specificity of two strains of the entomopathogenic hyphomycete Metarhizium anisopliae
Authors: Fargues Jacques F. , Robert Pierre H.
Published: May 2010

The effects on pathogenicity of Metarhizium anisopliae (Metsch.) Sor. following one or more passages through the original and the heterologous insect host species were investigated by using two pathotypes specific for Cetonia aurata L. and Oryctes rhinoceros L., respectively. A significant increase in virulence occurred after a single host passage. Thus, the infection potential of host-passed inocula could be increased by a factor of 10 to 100, and its host-induced adaptation was almost complete after the first in vivo passage. Bacteria located on the integument of the host cadaver were not implicated in this phenomenon. When the fungus was again grown on artificial medium, the loss in virulence was also very fast. Consequently, changes in virulence of the two tested strains seemed to be phenotypic responses implicating inducible enzymatic mechanisms. Nevertheless, the parasitic behaviour of the two pathotypes toward the larvae of the nonsusceptible species was not modified by host passaging through their respective insect hosts. It is concluded that changes in entomopathogenic hyphomycete virulence, resulting from host passage, concern only the naturally susceptible host species.
Diploid protoplasts in Schizosaccharomyces pombe: formation, growth, and sporulation
Authors: Sipiczki M.
Published: May 2010

Diploid cells of Schizosaccharomyces pombe heterozygous for the mating type region (h−/h+) were converted into protoplasts. On sporulation medium the diploid protoplasts either grew vegetatively or underwent meiosis resulting in four viable ascospores. Sporulation (without regenerating of cell wall) or growth (or conversion to cells) were found to be alternative possibilities.
Effects of inhibitors on early protein, RNA, and lipid synthesis in germinating vesicular–arbuscular mycorrhizal fungal spores of Glomus caledonium
Authors: Beilby John P.
Published: May 2010

The incorporation of isotopically labelled precursors, [1-14C]leucine, [2-14C]uracil and [1-14C]acetate, by germinating spores of the vesicular–arbuscular mycorrhizal fungus Glomus caledonium was investigated after prior incubation with several metabolic inhibitors. Inhibition of isotope incorporation was greatest with ethidium bromide and cycloheximide and least with chloramphenicol and actinomycin D. The incorporation of [1-14C]leucine into protein was reduced by 92% within 60 min of incubation in either ethidium bromide at 5 μg/mL or cycloheximide at 100 μg/mL. For these studies time zero was coincident with dry quiescent spores being first wet. Lipid synthesis during germination of the spores was detected at 120 min by following the incorporation of [1-14C]acetate. At 51 h, incorporation was greater in the triacylglycerides and diacylglycerides than in the free sterols, phospholipids, or free fatty acid. Spores exposed to cycloheximide for 60 min after imbibition showed very little phospholipid synthesis and no free fatty acid synthesis. The synthesis of RNA after spore imbibition is also discussed.
Composés stéroliques des spores d'Anthurus muellerianus (Basidiomycète)
Authors: Herber R. , Villoutreix J. , Granger P. , Chapelle S.
Published: May 2010

We have shown the presence of lupeol, ψ-taraxasterol, germanicol, and β-amyrin in the sterol fraction isolated from the spores of Anthurus muellerianus. Besides these pentacyclic triterpenes, known up to now to be present in higher plants, we have also characterized ergosterol, methyl-24 cholesta-7, 22 diene ol-3β, and methyl-24 cholestene 7 ol-3β.[Traduit par le journal]
Influence de l'anaérobiose sur la composition en stérols de Mucor hiemalis
Authors: Herber R. , Villoutreix J. , Granger P. , Chapelle S.
Published: May 2010

Strict anaerobic cultures of Mucor hiemalis lead to major modifications of the quantitative and qualitative composition of sterols. Sterols of which the lateral chain contains an ethyl or ethylidene group in C24 are for the first time brought to evidence in a Mucorales. Isolation in the same conditions of E-ethylidene-24 (28) lanostene-8 ol-3β lets us suppose that sterols, which are absent in aerobic cultures, are derived from this triterpene of 32 C atoms.[Translated by the journal]
Effect of the dispersant Corexit 9527 on the microbial degradation of sulfur heterocycles in Prudhoe Bay oil
Authors: Foght J. M. , Fedorak P. M. , Westlake D. W. S.
Published: May 2010

Samples from a previous study observing the effects of Corexit 9527 on microbial degradation of aromatics and saturates in crude oil were reanalyzed by capillary gas chromatography with a sulfur-specific detector. The results show an inhibitory effect on degradation of sulfur heterocycles (such as benzothiophenes and dibenzothiophenes), dependent upon dispersant concentration and nutrient supplementation.
Bacteriophages of Halobacterium halobium: virion DNAs and proteins
Authors: Rohrmann George F. , Cheney Richard , Pauling Crellin
Published: May 2010

The DNAs from bacteriophages Hh-1 and Hh-3 that infect Halobacterium halobium were characterized. Both phages contain linear double-stranded DNA and show no relatedness based on restriction endonuclease fragment patterns. Hh-1 DNA has 67.05% guanine plus cytosine (G + C) and a molecular weight of 24.6 × 106, whereas Hh-3 DNA has 62.15% G + C and a molecular weight of 19.4 × 106. Polyacrylamide gel electrophoresis indicated that the major proteins of the two phages are of different molecular weights.
Prevalence of Azospirillum spp. in the rhizosphere of tropical plants
Authors: Kosslak Renee M. , Bohlool B. Ben
Published: May 2010

Azospirillum cultures were isolated from the roots of a variety of tropical plants. Presumptive isolates from selective medium were identified by biochemical and serological methods. Forty-eight percent of the isolates were identified as A. lipoferum and the rest as A. brasilense, nir+ or nir−. All of the isolates tested exhibited at least one heat-labile antigen with one or more of the three whole-cell reference antisera. Isolates identified as A. lipoferum were very similar to the reference strain SP59, while those identified as A. brasilense showed a greater degree of antigenic and biochemical diversity. No cross-reaction was detected between the four reference antisera used and strains of Azotobacter beijerinckia, A. chroococcum, A. vinelandii, Azomonas macrocytogenes, and A. agilis.
Studies on mutants affecting amidophosphoribosyltransferase activity in Saccharomyces cerevisiae
Authors: Nieto Daniel J. , Woods Robin A.
Published: May 2010

Mutants at the ade4 locus of yeast were isolated following mutagenesis of ade+ and ade2 with ultraviolet light (UV), ethylmethane sulphonate, and the acridine half mustard ICR-170. Tests for interallelic complementation, osmotic remediality, temperature sensitivity, and mutagen-specific reversion were carried out on 19 mutants. Six mutants showed interallelic complementation and fell into four groups, defining three complons. Three mutants were osmotic remedial and the same three were temperature sensitive. Three mutants induced by ICR-170 gave purine-excreting revertants, designated Pur6 or ade4.RCF, after exposure to UV. Activity of amidophosphoribosyltransferase (PRPPAT) was assayed in the ade4 mutants and other alleles at this locus. The ade4 mutants lacked activity of the enzyme; the alleles su-pur+, su-pur, PUR6, and Pur6, showed different levels of activity. The enzyme was subject to feedback inhibition by AMP and IMP in su-pur+ and PUR6; su-pur was hypersensitive to inhibition by AMP, whereas Pur6 was slightly resistant. Purine synthesis de novo was shown to be repressible in su-pur+ and constitutive in PUR6 and Pur6 by following the accumulation of aminoimidazole ribotide in the presence and absence of cycloheximide. These observations were confirmed by direct assay of enzyme activity.
Production of Bacillus sphaericus strain 1593 primary powder on media made from locally obtainable Nigerian agricultural products
Authors: Obeta Jason A. N. , Okafor Nduka
Published: May 2010

Five media, formulated from dried cow blood, mineral salts, and seeds from four species of legumes, were assessed for growth, sporulation, and insecticidal properties of Bacillus sphaericus strain 1593. Bacterial powders, prepared from broth, were assayed against Culex quinquefasciatus, Anopheles gambiae, and Aedes aegypti. Good growth and sporulation were obtained with all the media. The highest number of viable cells and spores per millitre (8.6 × 108 and 8.1 × 108) were obtained in media containing ground seeds of Vignia unguiculata, Voandzeia subterranean, and Arachis hypogea. All powders were effective against C. quinquefasciatus and A. gambiae. Powders from media containing Arachis hypogea were the most effective with LC50's of 4.344 × 10−3 ± 1.650 × 10−4 and 0.193 ± 1.376 × 10−2 μg/mL for C. quinquefasciatus and A. gambiae, respectively. Aedes aegypti larvae were only slightly susceptible to the powders. This investigation shows that these media can be used for the production of B. sphaericus 1593 primary powder.
The possible role of some enzymes in sclerotia formation in Aspergillus ochraceus
Authors: Paster Nachman , Chet Ilan
Published: May 2010

The role of some enzymes in sclerotia production by Aspergillus ochraceus was studied using a sclerotia-producing strain grown under conditions in which sclerotia production was either favoured or inhibited. In addition, a mutant strain incapable of producing sclerotia was used. No significant differences in patterns of soluble proteins, polyphenol oxidase, and esterases could be detected electrophoretically by gel electrophoresis, while the peroxidase pattern of both the sclerotia-producing strain and the mutant showed three bands as compared with two bands that appeared when sclerotia formation was inhibited. The activities of the tricarboxylic acid cycle enzymes, malate dehydrogenase and succinate dehydrogenase, and those of the pentose-phosphate pathway, glucose-6 phosphate dehydrogenase and 6-phosphogluconate dehydrogenase, were almost identical in sclerotia- and nonsclerotia-producing mycelia. The activities of isocitrate lyase and malate synthetase, key enzymes of the glyoxylate cycle, and that of glyoxylate dehydrogenase which is related to this cycle were significantly reduced when sclerotia formation was inhibited either by methionine or by high levels of CO2. It is suggested that the glyoxylate cycle plays an important role in sclerotia formation in the fungus.
Competitive ability, effectiveness, and succinate – triphenyl tetrazolium chloride reductase activity of mutant strains of chick-pea (Cicer arietinum L.) Rhizobium sp.
Authors: Rai Raman , Prasad V. , Sharma S. D. , Shukla I. C.
Published: May 2010

Chick-pea Rhizobium strain RG 4 was treated with 200 μg/mL of N-methyl-N-nitro-N′-nitrosoguanidine and 14 mutant strains isolated. Two mutant strains were found to be nonnodulating in the absence of certain amino acids. On the basis of nodulation, two mutant strains (M 38 and M 46) were found to be equally competitive against each other. Mutant strains M 38 and M 46 when applied together produced the maximum nodulation, nitrogenase activity, phenanthroline-reactive iron, and least tetrazolium reductase activity as compared to other pairwise combinations of mutant strains. It was also observed that the correlation between tetrazolium reductase and nitrogenase activity was highly negative.
Libération d'aminoacides et d'électrolytes par des souches de Nectria haematococca (Berk. & Br.) Wr. mutées pour la production de pigments
Authors: Parisot Denise
Published: May 2010

Strains of N. haematococca, differing in their abilities to produce metabolites related to fusarubin, were exposed to 2 °C or treated with various chemicals. The effects of these treatments on cellular permeability were followed by measuring amino acid or electrolyte leakage. Some strains with enhanced metabolite production were shown to be more sensitive to cold treatment and less sensitive to nystatin and digitonin than strains yielding low amounts of metabolites. The results suggest that some mutations leading to pigment hyperproduction might determine plasma membrane alterations.
Observation of symbiote migration in human body lice with scanning and transmission electron microscopy
Authors: Eberle M. W. , McLean D. L.
Published: May 2010

Bacterial symbiotes in the human body louse Pediculus humanus migrate from the mycetome to the lateral oviducts during the adult molt. Their migration was first described by Ries (E. Ries. 1931. Z. Morphol. Oekol. Tiere, 20: 233–367.), who examined sectioned specimens with light microscopy. The present study is a more detailed investigation which involves the use of scanning and transmission electron micrographs. The results of our studies confirm Ries' observations. Micrographs are presented of symbiotes emerging from the mycetome, migrating to the reproductive tract, and invading the lateral oviducts.
Release of protoplasts from the galactose oxidase producing mold, Dactylium dendroides
Authors: Amaral Déa , Kubicki Doroty , Terenzi Hector F.
Published: May 2010

Osmotically sensitive protoplasts were released from the mycelium of Dactylium dendroides, using Megalobolinus paranaguensis digestive juice as a lytic enzyme. The conditions for obtaining stable protoplasts were determined. The maximum number of protoplasts was obtained from 15-h growing mycelium, using MgSO4 as osmotic stabilizer, in the presence of 0.015 M Sorensen phosphate buffer, pH 5.6. MgSO4 proved to be of considerable importance in the release of protoplasts in this fungus. Regeneration of the protoplasts was demonstrated in normal growth medium supplemented with 0.8 M mannitol and 2.5% agar.
DNA homology, phage-typing, and cross-nodulation studies of rhizobia infecting Galega species
Authors: Lindström Krishna , Jarvis B. D. W. , Lindström P. E. , Patel J. J.
Published: May 2010

The taxonomic status of Rhizobium nodulating Galega sp. is poorly defined. Earlier reports suggest that the rhizobia infecting G. officinalis should be included in the R. leguminosarum species or in the "fast-growing lupin – cowpea complex." Therefore organisms nodulating G. orientalis and G. officinalis were studied using cross nodulation, DNA homology, and phage typing. No cross-nodulation relationship between the Galega rhizobia and rhizobial strains from the major taxonomic groups was found. The mean relative DNA homology of 10 strains of Rhizobium nodulating Galega with reference DNA from strain HAMBI 540, which forms effective nodules on G. orientalis, was 77 ± 9%, compared with 19 ± 6% for 20 strains from other host plants. The Galega rhizobia formed a unique phage-typing group, not related to the major groups of fast growers, in agreement with the DNA homology and cross-nodulation results. These data indicate that the Galega rhizobia form a specific taxonomic group within the genus Rhizobium.
Alpha-ketoglutarate metabolism by cytochrome-containing anaerobes
Authors: Caldwell Daniel R. , Rasmussen Carolyn K.
Published: May 2010

During growth in the presence of tracer amounts of exogenously supplied alpha-keto[1-14C]glutarate (AKG) or alpha-keto [5-14C]glutarate, cytochrome-containing Bacteroides fragilis strain 2044 and Bacteroides vulgatus strain 8482 incorporated extremely small amounts of radioactivity into cell macromolecules and protoheme. Under identical conditions, Bacteroides "ℓ" strain 7 CM and Bacteroides buccae strain J1 incorporated substantial label from [5-14C]AKG, but not [1-14C]AKG, into cellular macromolecules and protoheme. Bacteroides succinogenes strain S85 incorporated radioactivity from both [1-14C]AKG and [5-14C]AKG into cell macromolecules, but only label from [5-14C]AKG appeared in protoheme. Selenomonas ruminantium strain HD1 and Butyrivibrio fibrisolvens strain D1, both of which are devoid of cytochromes, incorporated substantial label from both [1-14C]AKG and [5-14C]AKG into cell macromolecules, but failed to incorporate label from either position into protoheme. Bacteroides ruminicola sp. brevis strain GA33 incorporated label from both [1-14C]AKG and [5-14C]AKG into both cell macromolecules and protoheme. A substantial portion of the heme synthesized by this organism may be formed by the "plant" pathway involving the intact use of the AKG carbon skeleton. Major differences exist in the manner and extent of AKG utilization among cytochrome-containing anaerobes and between these organisms and bacteria devoid of cytochromes obtained from similar environments.
Colony counting on hydrophobic grid-membrane filters
Authors: Sharpe Anthony N. , Diotte Marcel P. , Dudas Istvan , Malcolm Stephen , Peterkin Pearl I.
Published: May 2010

A device to facilitate manual scoring of hydrophobic grid-membrane filters (HGMF) is described. Variations in scores were generally less than 2.5% between 41 analysts from six laboratories, who, using the apparatus, scored a set of five specimen HGMF in different ways, and there was good agreement between scores from positive and negative grid-cell counts by each analyst. A scoring procedure for use in routine microbiological analysis, suitable for HGMF at various degrees of saturation, is recommended.
The ultrastructure of sporulation in Sporosarcina ureae
Authors: Robinson Ralph W. , Spotts Charles R.
Published: May 2010

The morphology and ultrastructure of two strains of Sporosarcina ureae at various stages of growth and sporulation were examined by transmission electron microscopy. Sporulation begins with nonpolar cross wall growth as in vegetative division. Normal wall extension stops before complete septation, but membrane extension continues to completely bisect the cell. One of the cells so formed then engulfs the other by extension of the membrane. Germ cell wall and cortex material is then laid down, and the engulfed cell develops into a mature endospore in much the same way as in Bacillus species. After maturation, in broth cultures the spore remains in the mother cell. Lysis has not been observed over a period of several months. There are significant similarities between the phenotypic and ultrastructural characteristics of S. ureae and certain members of the species Bacillus suggesting a close phylogenetic relationship.
An electron spin resonance investigation of Bacillus megaterium KM spore inner and cell membranes
Authors: Elmes M. L. , Wilkins P. O. , Fitz-James P. C.
Published: May 2010

The viscosity of Bacillus megaterium KM spore membranes and vegetative cell membranes was studied by electron spin resonance spectroscopy. Although the phospholipid extracts have similar spectra and fluidity profiles, the spore inner membrane is more viscous than the vegetative cell membrane in the coat-stripped spores, cells, and membrane fractions. This increased viscosity could reflect a more extensive lipid–protein interaction in the spore inner membrane. The changed environment, i.e., dehydrated core and high calcium ion content of the inner membrane in the intact coat-stripped spore, could also have some effect on the membrane viscosity.
Phosphoenolpyruvate-dependent phosphorylation of α-methylglucoside in Streptococcus sanguis ATCC 10556
Authors: Vadeboncoeur Christian , Trahan Luc
Published: May 2010

Spontaneous mutants defective in some undefined membrane components of the phosphoenolpyruvate:glucose phosphotransferase system were isolated by plating cells of Streptococcus sanguis ATCC 10556 onto an agar containing lactose and 10 mM 2-deoxyglucose. Toluenized cells of these mutants were defective in their ability to catalyse the phosphoenolpyruvate-dependent phosphorylation of 2-deoxyglucose but were still able to phosphorylate α-methylglucoside. The phosphorylation of α-methylglucoside was essentially dependent on phosphoenolpyruvate and required the presence of both soluble and membrane components. It was concluded that S. sanguis possessed two different phosphoenolpyruvate:glucose phosphotransferase systems.
Isolation and identification of N2-fixing Pseudomonas associated with wetland rice
Authors: Barraquio W. L. , Ladha J. K. , Watanabe I.
Published: May 2010

Semisolid yeast extract medium amended with glucose and tryptic soy agar were used to isolate aerobically N2-fixing (C2H2-reducing) heterotrophic bacteria from the root of wetland rice. The isolates were identified as Pseudomonas by gel immunodiffusion and fluorescent antibody techniques in combination with their morphological, cultural, and biochemical characteristics. The N2-fixing H2-utilizing Pseudomonas described in this paper is a new species.
Determination of the most frequent N2-fixing bacteria in a rice rhizosphere
Authors: Bally R. , Thomas-Bauzon Danièle , Heulin Th. , Balandreau J. , Richard C. , Ley J. De
Published: May 2010

Representative N2-fixing bacteria have been isolated from the rhizosphere of rice using the "spermosphere model." They have been characterized using conventional biochemical tests, DNA composition, and DNA–rRNA hybridization studies. In addition to a large number of Enterobacteriaceae, the most commonly encountered isolates belong to the genus Azospirillum and to Pseudomonas paucimobilis, a taxon related to Flavobacterium capsulatum. A nonmotile Azospirillum has been found.
Isolation and genetic analysis of Azospirillum brasilense Nif− mutants
Authors: Jara P. , Quiviger B. , Laurent P. , Elmerich C.
Published: May 2010

After ethylmethane sulfonate mutagenesis of Azospirillum brasilense strain 7000, mutants devoid of nitrogenase activity were isolated. Partial diploids were constructed by introducing plasmids pAB35 and pAB36 into the Nif− mutants. The two plasmids were derivatives of the broad host-range plasmid vector pRK290. Plasmid pAB35 contained a 6.7 kilobase pairs (kb) EcoRI fragment which carried the nifHDK gene cluster cloned from strain 7000. Plasmid pAB36 contained the same fragment from which a 2.6-kb PstI fragment that likely covers nifK, and a part of nifD was deleted. The restoration of a Nif+ phenotype by pAB35, but not by pAB36, was observed in the case of mutant 7571, which might be impaired in a structural gene for the nitrogenase complex.