bluuebunny/crossref_metadata_2025 huggingface dataset:
A p-nitrophenyl α-galactoside hydrolase from Pseudomonas atlantica. Localization of the enzyme
Authors: Day D. F. , Gomersall M. , Yaphe W.
Published: April 2010

A p-nitrophenyl α-galactoside hydrolase is partially released when whole cells of Pseudomonas atlantica are converted to spheroplasts. The p-nitrophenyl α-glactoside hydrolase is completely inactivated by treatment of whole cells with diazonaphthalene – disulfonic acid (NDS), a reagent which does not penetrate the cytoplasmic membrane. Under the conditions used no inactivation of lactic acid dehydrogenase was observed. A specific staining procedure for this enzyme for use in electron microscopy was developed. The results with this technique in conjunction with the results of spheroplasting and NDS localization suggest that p-nitrophenyl α-galactoside hydrolase is located in or on the double-track membranes, primarily on the outer double track.
Factors affecting the immunizing activity of ribosomal fractions isolated from Mycobacterium tuberculosis var. bovis strain BCG
Authors: Portelance V. , Brasseur R. , Boulanger R. P.
Published: April 2010

Levels of antituberculous immunity similar to those induced by live BCG vaccine were detected in CF1 mice immunized with ribosomal fractions isolated from Mycobacterium tuberculosis var. bovis, strain BCG, and challenged 3 weeks later with the virulent H37Rv strain of Mycobacterium tuberculosis var. hominis. The activity of the crude ribosomal preparations was found to be a function of the immunizing doses and the immunity induced by 1.0-mg doses remained at the same high level after 4 weeks of storage at 4 °C but decreased markedly thereafter. Dialysis and lyophilization had no detrimental effects on the activity of the crude preparations whereas purification by column chromatography on Sephadex G-200 annihilated their biological activity. Crude low-polysaccharide-containing preparations were found inactive even at the 1.0-mg dose level and results of experiments performed with crude ribosomal fractions of varying polysaccharide contents strongly suggest that polysaccharides, or RNA-polysaccharide complexes, may play an important role in the induction of immunity with crude ribosomal fractions isolated from the BCG strain of Mycobacterium tuberculosis var. bovis.
Envelope proteins in Neisseria
Authors: Russell R. R. B. , Johnson K. G. , McDonald I. J.
Published: April 2010

The proteins of the cell envelope of Neisseria sicca strain ATCC 9913 have been examined by SDS – polyacrylamide gel electrophoresis. Some 20 proteins were resolved from the total envelope fraction, and nearly all of these were found to be localized in the outer membrane. Preparations of the "free-endotoxin" fraction differ from the outer membrane only in lacking a few minor proteins.The behavior of several of the envelope proteins on electrophoresis can be modified by changing the temperature of sample solubilization, and also by alteration of the growth medium. Experiments with phosphate-limited cultures showed that certain periplasmic proteins are closely associated with free endotoxin.Mutations which result in altered outer membrane permeability to antibiotics were found to cause changes in cell envelope protein composition.A comparison of the envelope proteins of eight species of non-pathogenic Neisseria showed that each had a characteristic composition. A classification of the organisms based on the relatedness of the protein patterns seen on SDS-polyacrylamide gels was in close agreement with classifications based on more usual methods.
Specific inhibition of sclerotium formation by 2-mercaptoethanol and related sulfhydryl compounds in Sclerotium rolfsii
Authors: Christias Christos
Published: April 2010

Sclerotium formation in Sclerotium rolfsii was completely inhibited by 2-mercaptoethanol at a concentration of 2–4 mM without any adverse effect on mycelial growth. Concentrations lower than 2 mM had no effect on mycelial growth and sclerotium formation, whereas both were inhibited at concentrations higher than 4 mM. Complete inhibition of sclerotium formation with no effect on mycelial growth was also obtained by propyl mercaptan, 1-butyl mercaptan and 2-butyl mercaptan at a concentration of 0.10 mM. Sclerotium formation was also inhibited by benzyl mercaptan and thioglycolic acid at 0.15 mM and 2–4 mM concentration respectively, whereas it was only partially inhibited by L-cysteine and glutathione at 20 mM. Mycelium grown for 21 days in nutrient medium supplemented with mercaptoethanol at a concentration of 3 mM, when transferred into fresh medium without the chemical, grew normally and produced abundant mature sclerotia. Mercaptoethanol inhibited the initiation as well as the further development of young, unpigmented sclerotia. The mechanism of sclerotium formation was arrested completely when mercaptoethanol was added to the growth medium at any time between inoculation and the appearance of sclerotia of the "development" stage. It is suggested that the specific inhibitory action of mercaptoethanol could be used to study the mechanism of sclerotium formation.
Physiological differences among isolates of Phytophthora cinnamomi
Authors: Kelley W. D.
Published: April 2010

Significant differences in amylase, β-glucosidase, and phosphatase activities were observed among four Phytophthora cinnamomi isolates grown in nutrient-amended sterilized soil for 20 days. Amylase pH optima for the four isolates were within a relatively narrow range; at pH 5.5 each isolate was within 90% of its peak activity. Isolates SB-216-1, 1-281, and C-39 each exhibited maximal β-glucosidase activity at pH 5.0 and maximal phosphatase activity at pH 5.0–5.5. Maximal activity for these two enzymes of isolate A-7725 occurred at pH 3.5. In timed experiments, isolates 1-281 and A-7725 exhibited greater amylase activities than did the other two isolates. For β-glucosidase, greatest activity was observed for SB-216-1; activity of 1-281 was intermediate and least activity was observed for isolates A-7725 and C-39. Isolates SB-216-1 and 1-281 exhibited greatest phosphatase activities; isolate C-39 was intermediate in activity, and A-7725 was least active. Results indicate that significant differences exist among the isolates tested and that these differences can be quantitatively measured by the methods described.
Effect of temperature on the activity and synthesis of glucose-catabolizing enzymes in Pseudomonas fluorescens
Authors: Lynch William H. , MacLeod Janet , Franklin Mervyn
Published: April 2010

The activity of the enzymes of the oxidative non-phosphorylated pathway, glucose and gluconate dehydrogenases, were not significantly affected by changes in the assay temperature. Both enzymes demonstrated only a threefold difference in activity when compared at assay temperatures of 30 °C and 5 °C. In contrast, the enzymes involved in the direct phosphorylation and catabolism of glucose or its oxidation products, gluconate and 2-ketogluconate, exhibited a more pronounced response to decreasing assay temperatures. At least one enzyme in each pathway, involved in the direct phosphorylation and catabolism of glucose or 2-ketogluconate (2KG), demonstrated an eightfold decrease in activity with a decrease in assay temperature from 30 °C to 5 °C. A similar decrease in assay temperature resulted in a fivefold decrease in activity of the enzymes involved in the direct phosphorylation and catabolism of gluconate. The observed differential effect of temperature on the activity of the enzymes of glucose catabolism and on the accumulation of direct oxidation products during growth with glucose in P. fluorescens E-20 is discussed.Growth with glucose at 5 or 20 °C resulted in high induced levels of all glucose-catabolizing enzymes examined when compared with the levels of these same enzymes in pyruvate-grown cells. However, only low levels of glucose dehydrogenase were detected during growth at 30 °C with glucose, gluconate, or 2-KG. Similarly, only low levels of gluconate dehydrogenase were detected during growth with glucose at 30 °C, although a weak induction was observed during growth with gluconate or 2-KG at 30 °C. The levels of 2-KG kinase plus KPG reductase during growth at 30 °C were undetectable with glucose, weakly induced with gluconate, and fully induced with 2-KG. High induced levels of glucose dehydrogenase, gluconate dehydrogenase, and 2-KG kinase plus KPG reductase were present during growth at 20 °C with glucose or 2-KG. The low levels of glucose and gluconate dehydrogenases present at a growth temperature of 30 °C was not due to heat lability of the enzymes at this temperature. The low amounts of these two enzymes during growth with glucose at 30 °C probably prevented sufficient inducer(s) formation from glucose to allow induction of enzymes of 2-KG catabolism. The results demonstrated that temperature may regulate the pathways of glucose dissimilation by regulating, either directly or indirectly, the activity and synthesis of the enzymes involved in these pathways.
Osmophilous fungi in the salt marshes of Kuwait
Authors: Moustafa A. F.
Published: April 2010

During an investigation of the mycoflora inhabiting saline soils in Kuwait, special attention was focused on osmophilous fungi. A total of 101 species belonging to 46 genera were encountered from 40 soil samples collected from salt marshes using Czapek's agar supplemented with 40% sucrose. Soil samples were collected from different habitats at different distances from the water edge. Soils near to the water edge were poor in their fungal content, while those taken from areas covered by Juncus arabicus contained highest fungal populations. The recorded genera were classified as follows: 7 were of high frequency of occurrence, 8 moderate, 17 low, and 13 were rare. The order of dominance was Aspergillus, Alternaria, Penicillium, Cephalosporium, Fusarium, Stachybotrys, and Drechslera. Comparison between our results and those in other studies showed that there is no fungal flora characteristic of saline soils.
Bactericidal substance produced by Haemophilus influenzae b
Authors: Venezia R. A. , Robertson R. G.
Published: April 2010

During bacteriophage studies on Haemophilus influenzae, it was observed that encapsulated type b and unencapsulated Rb strains released a bactericidal substance active against types a, c, d, e, and f H. influenzae, non-typable H. influenzae strains, other Haemophilus species, and certain members of the Enterobacteriaceae. The bactericidal activity was assayed by a plaque test utilizing an Rd strain as an indicator lawn and was also demonstrated in mixed broth cultures of a producer strain and an indicator strain. Immediate lysis of sensitive bacteria by the factor was not evident. The factor is sensitive to trypsin but resistant to deoxyribonuclease, treatment with 2-mercaptoethanol, lipase, α-amylase, and heating in a 100 °C water bath for 20 min. The activity is not dependent upon increased Ca2+ or Mg2+ concentration as is necessary for HP1C1 and S2 phage propagation. The bactericidal factor is not pelleted by high-speed centrifugation at 150 000 × g for 6 h. Treatment with ultraviolet light or mitomycin C does not result in observable phage, phage-like particles, or increased bactericidal activity. The bactericidal factor is not a typical small molecular weight "colicin-like" bacteriocin in that it is not inducible, has a wider range of activity, and does not kill by "single-hit" kinetics. On preliminary characterization, it is a thermostable protein toxic to certain bacterial strains.
The relationship of acid-soluble glycogen to yeast flocculation
Authors: Patel G. B. , Ingledew W. M.
Published: April 2010

A relationship between yeast flocculation and intracellular acid-soluble glycogen has been established which has been substantiated using flocculation mutants (mutants with altered capacities to flocculate) as well as a normal strain of Saccharomyces carlsbergensis. Sound evidence exists to implicate physiological differences in carbohydrate metabolism (glycogen storage) to this physical property of brewing significance.
A replica-plating method for the identification of Micrococcaceae
Authors: Bibel David J. , Smiljanic Roko J. , LeBrun Joseph R.
Published: April 2010

A procedure of replica plating is described whereby all isolated colonies of Micrococcaceae can be identified with relative ease and rapidity. The method is as accurate as the recommended procedure, but permits a more complete and economical analysis of cutaneous flora in large-scale surveys. In this system, Baird-Parker carbohydrate medium was found somewhat superior to standard medium as was incubation at 35 °C instead of the customary 30 °C. Baird-Parker's broth medium for acetoin production yielded more positive results than did commercial medium, although the reactions were less distinct. However, an agar acetoin test medium was found as good or perhaps even better than Baird-Parker's medium. The classification schemes of Baird-Parker and Bergey's Manual were contrasted in the analysis of data.
Variation in the lethal response in mice to yeast-like and pseudohyphal forms of Candida albicans
Authors: Mardon D. N. , Gunn J. L. , Robinette Jr. E.
Published: April 2010

The lethal response in mice to yeast-like cells of Candida albicans grown for 3, 6, or 9 h in a defined minimal culture medium was more severe than that observed with corresponding pseudohyphal preparations. This differential effect could be only partially correlated with the greater number of viable units in respective yeast-like cultures. No significant differences between yeast-like and pseudohyphal suspensions were detected when turbidity–mass ratios were examined. The injection of physiological saline suspensions containing increasing quantities of yeast-like cells resulted in proportional decreases in mouse survival times. Conversely, when comparable experiments were conducted with pseudohyphal preparations no significant decreases in survival times occurred. The data indicate that these differences in the lethal response cannot be explained solely on the basis of a variation in the number of viable units or cell mass in corresponding yeast-like and pseudohyphal preparations. Factors contributing to this phenomenon may therefore include altered susceptibilities to host defense mechanisms in the early stages of the infectious process as a result of differences between these yeast-like and pseudohyphal inocula.
Pathways of carbohydrate metabolism in Mycobacterium tuberculosis H37Rv
Authors: Bai N. Jayanthi , Pai M. Ramachandra , Murthy P. Suryanarayana , Venkitasubramanian T. A.
Published: April 2010

Radiorespirometric studies using glucose labelled at 1, 2, 3–4, and 6 positions and enzymatic studies were conducted to determine the primary pathways of glucose dissimilation in Mycobacterium tuberculosis H37Rv. The pattern of 14CO2 recovery was C3−4 > C1 > C6 = C2. The Embden–Meyerhof pathway was found to be the predominant pathway for glucose oxidation, operative to the extent of 94%. The pentose phosphate pathway accounted for the remaining 6%. Maximum incorporation of 14C into cellular components was from C2 and C6 labelled glucose.
Susceptibility of clinical isolates of Staphylococcus aureus to killing by oxacillin
Authors: Best Gary K. , Koval Ann V. , Best Norma H.
Published: April 2010

Sixty clinical isolates of Staphylococcus aureus have been screened for their relative susceptibility to the killing action of oxacillin. Only one of these strains was found to be exceptionally resistant to the bactericidal effect of this and other β-lactam antibiotics. This ability to survive oxacillin inhibition of cell wall synthesis has been called "tolerance." The characteristics of the tolerant organism, which has been designated the Evans strain, in comparison with other isolates of S. aureus indicate that this form of resistance is not apparent from the minimal inhibitory concentration, is not related to an abnormal growth rate, and can be enhanced by treatment with N-methyl-N′-nitro-N-nitrosoguanidine.
Studies on gonococcal infection. II. Attachment and fate of gonococci in tissue-culture cells
Authors: Ota F. , Pontefract R. , Ashton F. E. , Diena B. B.
Published: April 2010

Neisseria gonorrhoeae 188, type 1, was cultured with monolayers of Rhesus monkey kidney (RE2) cells. Attachment of gonococci to RE2 cells occurred from about 2 h after inoculation and appeared maximal by 6 h when stained with crystal violet solution and examined under a light microscope. Preferential attachment of gonococci to the perinuclear region of tissue cells could not be demonstrated. Enumeration of the colony-forming units revealed that gonococci became rapidly attached to RE2 cells, increased in number, and after 8 h gradually decreased. The number of cell-free gonococci (not bound to tissue cells) remained constant for the first few hours and then changed in parallel with the cell-bound bacterial number. Gonococci did not multiply in tissue-culture medium.When penicillin was added to the system at intervals, neither cell-free nor cell-bound gonococci were recovered.Electron microscopy of RE2 cells infected with N. gonorrhoeae revealed no intact intracellular organisms, only gonococci attached to tissue cells and incompletely engulfed or partially digested gonococci.These observations indicate that gonococci only multiply extracellularly in the presence of RE2 cells. Furthermore, some gonococci were engulfed by RE2 cells, but appeared to be digested so rapidly that they could not multiply intracellularly.
Plasmid DNA in virulent and avirulent gonococci
Authors: Walker T. S. , Haak R. A. , Wegener W. S.
Published: April 2010

The presence of covalently closed circular (CCC) DNA in virulent and avirulent colonial types of Neisseria gonorrhoeae strain 2686, and of type 3 colonies of strain F62 was investigated. CCC DNA was present in each, and the percentage of plasmid relative to total DNA was similar. The percentage of CCC DNA was similar in cells grown on a solid as compared with a liquid medium and in cells grown in the presence of varying concentrations of glucose. No correlation could be established between the presence of plasmid DNA and virulence of N. gonorrhoeae.
Electron microscopy of vesicular-arbuscular mycorrhizae of yellow poplar. II. Intracellular hyphae and vesicles
Authors: Kinden Darrell A. , Brown Merton F.
Published: April 2010

Intracellular hyphae and vesicles in mycorrhizal roots of yellow poplar were examined by electron microscopy. An investing layer of host wall material and cytoplasm enclosed the endophyte within the cells. Young developing hyphae contained abundant cytoplasm and few vacuoles. As hyphae matured, they became highly vacuolated and accumulated carbohydrate (glycogen) and lipid reserves. Mature vesicles were engorged with lipid droplets, possessed a trilaminate wall, and were also enclosed by host wall material and cytoplasm. Compared with uninfected cells, infected cortical cells showed an increase in cytoplasmic volume, enlarged nuclei, and a reduction of starch reserves. Host nuclei were always proximal to the hyphae during hyphal development and deterioration. While other cytoplasmic components of infected and uninfected cells were comparable, large electron-dense bodies occurred in vacuoles of most cells containing hyphae. Deterioration of intracellular hyphae occurred throughout the samples examined. Septa separated functional and degenerating portions of the hyphae. Hyphal deterioration involved degeneration and ultimate disappearance of fungal cytoplasm as well as collapse of hyphal walls. Based on these observations, the authors hypothesize that deterioration of the endophyte may release significant quantities of mineral nutrients, via hyphal contents, which are absorbed by the host.
Ultrastructural studies of Chondromyces crocatus vegetative cells
Authors: MacRae Thomas H. , McCurdy Howard D.
Published: April 2010

Electron microscopy of sectioned, chemically fixed Chondromyces crocatus revealed a microorganism with a typical gram-negative cell envelope. The cytoplasm contained, in addition to tubules and two types of granules, a membrane-associated structure (MAS) that, although less extensive, bears some resemblance to polar membranes observed in flagellated bacteria. Examination of swarming cells negatively stained in situ, as well as thin sections, established that cell division occurs by septum formation and that well-defined mesosomes are associated with the process. Polar pili and a compact, amorphous slime layer surrounding the cells were evident in shadowed preparations of in situ cells. The slime layer and pili, by providing cell-to-cell interconnections, may influence the organized gliding movement characteristic of C. crocatus and other myxobacteria.
Effect of glutamic acid on the fatty acid and lipid composition of Choanephora cucurbitarum
Authors: Deven J. M. , Manocha M. S.
Published: April 2010

The fatty acid composition of the total, neutral, sterol, free fatty acid, and polar-lipid fractions in the mycelium of Choanephora cucurbitarum was determined. The major fatty acids in all lipid fractions were palmitic, oleic, linoleic, and γ-linolenic acid. Different lipid fractions did not show any particular preference for any individual fatty acid; however, the degree of unsaturation was different in different lipid fractions. Free fatty acid and polar lipid fractions contained a higher proportion of γ-linolenic acid than did triglyceride and sterol fractions. Addition of glutamic acid to the malt–yeast extract medium resulted in the biosynthesis of a number of long-chain fatty acids beyond the γ-linolenic acid. These fatty acids, e.g., C22:1, C24:0, and C26:0, were never observed to be present in the fungus when grown on a malt–yeast extract medium without glutamic acid. Furthermore, thin-layer chromatographic analysis showed a larger and denser spot of diphosphatidyl glycerol from the mycelium grown on glutamic acid medium than from the control mycelium. The possible significance of this finding is discussed.
Cultural, morphological, and physiological characteristics of Thermomonospora fusca (strain 190Th)
Authors: Crawford Don L.
Published: April 2010

The cultural, morphological, and physiological properties of Thermomonospora fusca (strain 190Th) are described. Its physiological properties show that this species is primarily a carbohydrate-degrading actinomycete which can use a wide range of plant sugars and polymeric carbohydrates as sources of carbon and energy. The culture does not use proteins or amino acids for carbon and energy, or as a nitrogen source. A few organic acids are utilized. Ammonia is the preferred nitrogen source. The culture has trace nutrient requirements which include biotin and an undetermined number of amino acids. These and other physiological characteristics are discussed in relation to the roles that T. fusca carries out as a saprophytic bacterium in nature. Its cultural and morphological properties are discussed in relation to the taxonomic status of this species in the literature.
Effects of zinc-smelter emissions on forest soil microflora
Authors: Jordan Marilyn J. , Lechevalier Mary P.
Published: April 2010

Within 2 km of a zinc (Zn) smelter in Palmerton, Pennsylvania, near the Lehigh Water Gap, up to 13.5% Zn by weight has been measured in the O2 horizon of the soil, and up to 8% Zn in the A1 horizon. The total numbers of bacteria, actinomycetes, and fungi (measured by dilution plate counts) were greatly reduced in the most severely Zn-contaminated soils compared with control soils. The reduction of microbial populations may be a partial cause of the decreased rate of litter decomposition at Lehigh Gap.Growth of most bacteria from control sites was reduced by 100 to 200 μM Zn, most actinomycetes by 100 μM Zn, and most fungi by 100 to 1000 μM Zn in thin-Pablum extract agar (TPab). All the tested actinomycetes and non-spore-forming bacteria isolated from Zn-contaminated Lehigh Gap soils were Zn-tolerant, growing normally in media containing 600-2000 μM Zn. Most fungi, regardless of source, were capable of at least 50% of normal growth at 700 μM Zn. Zinc-tolerant bacteria, actinomycetes, and fungi were readily isolated from low-Zn soils, suggesting that selection for Zn tolerance may proceed rapidly.Acidophilic Mortierella species have been selectively eliminated near the smelter, apparently because of elevated soil pH. Peyronellaea glomerata (Corda) Goidanich and Coniothyrium spp. were found only in the high-Zn soils.
A chemically defined medium for Aquaspirillum aquaticum ATCC 11330
Authors: Kropinski Andrew M.
Published: April 2010

Aquaspirillum aquaticum ATCC 11330 requires nicotinic acid for growth. Of 120 organic compounds screened as possible sole sources of carbon this bacterium will use 29.
The fine structure and the protein composition of γ phage of Bacillus anthracis
Authors: Watanabe Takashi , Morimoto Akinori , Shiomi Toshiro
Published: April 2010

The fine structure of γ phage of Bacillus anthracis was studied by electron microscopy with a negative-staining technique. The phage has a hexagonal head and a long tail without a sheath. By electrophoresis on polyacrylamide gels, the proteins of the phage particles are separate into 10 polypeptides with moleclar weights ranging from 140 000 to 12 000.
Infrared color photomicrography of soil microorganisms
Authors: Casida Jr. L. E.
Published: April 2010

The infrared color photomicrography technique for detecting unstained microbial cells in soil is revised for use with Kodak's recently introduced Ektachrome infrared film. This new version of the film required achromatic objectives instead of apochromats, and the use of a blue filter in addition to the previously required red filter. These filters also improve the visual focus capability of the operator. It was found that dry soil smears can be photographed as either immersion oil or aqueous mounts. Several makes of bright-field transmitted-light microscopes gave similar results. Phase microscopy, however, produced deteriorated image quality although the proper 'false' colors were produced.
Demonstration of the isolation of non-infective Alnus crispa var. mollis Fern. nodule endophyte by morphological immunolabelling and whole cell composition studies
Authors: Lalonde Maurice , Knowles Roger , Fortin J.-André
Published: April 2010

Two filamentous, branched, and septate actinomycetes were isolated from field-collected and from axenic in vitro produced root nodules of Alnus crispa var. mollis Fern. host plant. After their transfer to a chemically defined medium, these nodule isolates could not be distinguished from each other on the basis of morphology, cultural reactions, and whole cell composition and were considered to be the same species. They were morphologically similar to the root nodule endophyte, but were incapable of nodulating aseptic host plants growing in a nitrogen-deficient substrate. Whole cells of the nodule isolates were used for the production of rabbit antibodies. The resulting specific antiisolate antibodies were conjugated with fluorescein isothiocyanate and used in staining tests of the nodule endophyte. The immunofluorescence reactions demonstrated the homology of the nodule isolates with the nodule endophyte. After pectinase degradation of the endophyte capsule, the indirect immunoferritin method corroborated the fluorescent antibody (FA) staining reactions. There was no antigenic relationship between the nodule isolates and 13 known strains of actinomycetes as determined by the FA technique. Fluorescent antibody reactions of adsorbed conjugates suggested that endophytes of both Alnus crispa var. mollis Fern. and Alnus rugosa (DuRoi) Spreng. root nodules belong to a common serotype. The LL and mesoisomers of diaminopimelic acid were present in similar proportions in the nodule endophyte and in the nodule isolates. Glucose, mannose, and an unknown sugar were the predominant whole cell sugars in the nodule isolates, although trace amounts of arabinose and rhamnose were also displayed. The unknown sugar found in the nodule isolates was also present in trace amounts in the endophyte-suspension hydrolysate.
The fine structure of conidial development in the genus Torula. II. T. caligans (Batista and Upadhyay) M. B. Ellis and T. terrestris Misra
Authors: Ellis D. H. , Griffiths D. A.
Published: April 2010

Conidia of Torula caligans (Batista & Upadhyay) M. B. Ellis comb. nov. and T. terrestris Misra were examined by transmission- and scanning-electron microscopy. Torula caligans produced four-celled conidia in which the central cells were distinctly larger than the basal and apical cells. Conidia of T. terrestris were 4- to 7-celled long and ellipsoidal in shape. Conidiogenous cells in both species developed melanin only within the lowermost part of the lateral walls while the other cells of the conidium were uniformly melanized around the circumference of the cell; melanin in these cells being deposited within, at least, half the width of the cell wall. In both species new conidia arose from evagination of the hyaline apex of the conidiogenous cell and are therefore blastoconidia. The systematic relationships between T. caligans and T. terrestris and other species of the genus Torula are discussed.
Electron microscopy of vesicular-arbuscular mycorrhizae of yellow poplar. III. Host–endophyte interactions during arbuscular development
Authors: Kinden Darrell A. , Brown Merton F.
Published: April 2010

Scanning- and transmission-electron microscopy were used to examine developing and mature functional arbuscules in mycorrhizal roots of yellow poplar. Arbuscules developed from intracellular hyphae which branched repeatedly upon penetration into the host cells. Intermediate and late stages of development were characterized by the production of numerous, short, bifurcate hyphae throughout the arbuscule. Mature arbuscules exhibited a coralloid morphology which resulted in a considerable increase in the surface area of the endophyte exposed within the host cells. Distinctive ultrastructural features of arbuscular hyphae included osmiophilic walls, nuclei, abundant cytoplasm, glycogen, and numerous small vacuoles. All arbuscular components were enclosed by host wall material and cytoplasm during development and at maturity. In infected cells, host nuclei were enlarged and the cytoplasm associated with the arbuscular branches typically contained abundant mitochondria, endoplasmic reticulum, and proplastids. Ultrastructural observations suggested that nutrient transfer may be predominantly directed toward the fungal endophyte during arbuscular development and while mature arbuscules remain functional.
Evidence of respiratory tract infection induced by equine herpesvirus, type 2, in the horse
Authors: Blakeslee Jr. James R. , Olsen Richard G. , McAllister E. Scott , Fassbender Joanne , Dennis Richard
Published: April 2010

Five horses were experimentally exposed to equine herpesvirus 2 strain LK. Two young foals developed chronic pharyngitis (98 and 232 days, respectively). Growth characteristics, cytopathic effects (CPE), inclusion body formation, ether sensitivity, and immunofluorescent analysis indicated that the virus recovered from infected animals was a herpesvirus serologically identical with, or at least antigenically related to EHV-2 strain LK. No significant complement-fixing (CF) or virus-neutralizing (VN) antibody responses were observed in adult horses while both foals demonstrated a rise in CF antibody titer. One of the two foals demonstrated a rise in VN antibody only. The results suggest that EHV-2 virus induced chronic pharyngitis, primarily the result of lymphoid proliferation, with no overt clinical signs.
Method for detecting antibody formation to Neisseria gonorrhoeae
Authors: Pribnow James F. , Hall Joan M. , Besemer Diana J. , Vedros Neylan A.
Published: April 2010

The use of Concanavalin A as a coupling agent for sensitization of sheep erythrocytes with an alkaline extract of Neisseria gonorrhoeae organisms is described in this paper. The sensitized erythrocytes were used in a plaque assay for enumeration of antibody-producing cells and in hemagglutination and hemolysin tests for determination of serum antibody.Rabbits were immunized intraperitoneally, intravenously, or via the footpad with viable N. gonorrhoeae organisms. Plaque-forming cells were found in draining lymph nodes and in the spleens of these rabbits. The cells from some rabbits also lysed sheep erythrocytes coated with an alkaline extract prepared from Neisseria meningitidis organisms. No antibody-producing cells were found in the lymphoid tissues of normal rabbits.Rabbits immunized by all three routes developed high hemagglutination and hemolysin titers. Hemolysin titers were significantly higher than hemagglutination titers when both tests were performed on the same serum samples. Pooled antiserum from these rabbits also lysed erythrocytes coated with a meningococcal antigen, but titers for the specific immunizing species were higher.
Degradation of ioxynil and bromoxynil as measured by a modified spectrophotometric method
Authors: Hsu JeMin C. , Camper N. D.
Published: April 2010

A modified spectrophotometric method was developed to estimate ioxynil and bromoxynil residues. The method when compared with a 14C-tracer method was less sensitive but allowed rapid and accurate estimation of the herbicides.A clay loam soil with high organic matter content, which degraded ioxynil completely to CO2, also degraded bromoxynil completely. Bromoxynil degradation proceeded at a faster rate than that of ioxynil. The half-life of degradation was estimated to be 7 days for bromoxynil and 9–10 days for ioxynil. However, soil microorganisms which degraded ioxynil either completely to CO2 or partially did not seem to completely degrade bromoxynil. Degradation products from bromoxynil were detected on thin-layer chromatograms of extracts from pure cultures containing an exogenous carbon source. Complete degradation of bromoxynil and ioxynil in soil could be due to the action of different microorganisms.
Purification and characterization of tuberculin-active components from BCG
Authors: Laguerre M. , Turcotte R.
Published: April 2010

The tuberculin activity of protoplasmic extracts isolated from living BCG was purified successively by gel filtration on Sephadex G-100 and G-75, and by electrophoresis on 7.5% and on gradient (6–18%) polyacrylamide gels. The tuberculin-active fractions, as determined in BCG-sensitized guinea pigs, were used as the starting material for each of the following fractionation steps.The physicochemical properties and the antigenic activity of the biologically active fractions have shown that a single component, or only a few ones with similar properties, possessed high tuberculin activity. These active components were proteins having relatively high molecular weights (about 72 000) and could behave as antigens.
Cell wall composition and incorporation of radio-labelled compounds by Veillonella alcalescens
Authors: Winter P. F. , Delwiche E. A.
Published: April 2010

The cell wall of Veillonella alcalescens was shown to have a typically Gram-negative appearance and composition. The wall contains 24% lipid, 0.8% phosphorus, and 6.8% hexosamine. It is estimated to contain about 5% murein, unlike the 24% reported by other for Veillonella parvula. The amounts of 19 amino acids, including diaminopimelic acid, were determined. Though Veillonella sp. cannot metabolize sugars for energy, V. alcalescens incorporates ribose and fructose by separate, specific mechanisms and uses most of the incorporated sugar in nucleic acid synthesis. Large excesses of either sugar in the medium do not repress gluconeogenesis from the pyruvate level. We have been unable to detect phosphoglyceromutase (EC 2.7.5.3) by several assay methods but have no indication of a gluconeogenic pathway other than reverse glycolysis.
Pyruvate inhibition of the carbon dioxide fixation of the strict chemolithotroph Thiobacillus thiooxidans
Authors: Butler Richard G.
Published: April 2010

A flow-through dialysis system used to decrease the concentrations of toxic organic materials excreted by Thiobacillus thiooxidans permitted an improved efficiency of carbon dioxide fixation when compared with cells taken from the usual shaken culture. The additions of various concentrations of pyruvic acid and succinic acid inhibited growth significantly. Pyruvate at a concentration of 5 × 10−3 M completely inhibited the respiration of resting cells oxidizing sulfur. The toxicity of pyruvic acid was found to be permanent as evidenced by the inability to obtain satisfactory oxidation rates after washing the exposed cells twice in buffer. Both pyruvate (10−3 M) and succinate (10−3 M) inhibited carbon dioxide fixation by 84%.
Growth characteristics of a cell line derived from the pig oviduct
Authors: Bouillant A. M. P. , Genest P. , Greig A. S.
Published: April 2010

Further evidence for the establishment of the pig fallopian tube (PFT) cell line as a continuous cell line was shown by an increase in the maximum population density as the number of subcultures increased. The optimal pH and temperature–growth ranges appeared to be 7.4–7.8 and 37–41 °C respectively, and the population doubling time was 20–25 h under optimal growth conditions. With progressive subculture, the serum requirements dropped from 20 to 2%. A plating efficiency of 2 to 4% was found in all serial subcultures. Colonies were observed in agar suspension culture at the 146th subculture and thereafter. Chromosomal alterations were found in the 100th subculture and thereafter.
Characteristics of a facultatively psychrophilic Acinetobacter species isolated from river sediment
Authors: Breuil Colette , Novitsky T. J. , Kushner D. J.
Published: April 2010

A facultatively psychrophilic bacterium isolated from river sediment was identified as an Acinetobacter species, similar to those previously characterized as A. lwoffi. The strain was extremely lipolytic and hemolytic. Some action on crude oil was also observed. The organism was able to utilize a wide variety of carbon and energy sources when tested at both 20 and 30 °C.A comparison is made with the previously proposed type strain of A. lwoffi. The bacteria had a Gram-negative cell wall containing an electron-dense intermediate layer. Cell division occurred with the formation of a septum and slight constriction.
Induction of microbial variants of Pseudomonas pseudomallei in cultured rabbit alveolar macrophages
Authors: Kishimoto Richard A. , Eveland Warren C.
Published: April 2010

Cultured alveolar and peritoneal macrophages obtained from normal and immunized rabbits were used to induce wall-defective microbial variants of Pseudomonas pseudomallei. Variants were induced only by normal alveolar macrophages. The variants reverted to typical Pseudomonas forms either spontaneously or upon transfer into broth or agar.
Morphological, physiological, and biochemical characteristics of some violet-pigmented bacteria isolated from seawater
Authors: Gauthier M. J.
Published: April 2010

Sixteen violet-pigmented heterotrophic bacilli were isolated from Mediterranean coastal waters. Morphological and physiological studies showed that they have a number of characteristics specific to the genus Chromobacterium. However, the absence of catalase, the presence of oxidase, and, more especially, the low percentage of bases guanine and cytosine in their DNA exclude them from the genus. The specificity of some characters assigned to Chromobacterium can thus be discussed. Several features allow us to consider such bacteria as being related to the genus Alteromonas; their consistency within the 16 strains investigated leads us to consider them as a single species, for which the specific name Alteromonas luteo-violaceus (sp. nov.) is proposed.
Temporal origin of viral phospholipids of the enveloped bacteriophage ϕ6
Authors: Sands Jeffrey A. , Lowlicht Roger A.
Published: April 2010

The enveloped bacteriophage ϕ6 contains a higher relative level of the negatively charged phospholipid phosphatidylglycerol than is found in the membranes of the host bacterium. During infection of Pseudomonas phaseolicola with ϕ6, the level of phosphatidylglycerol synthesis increases significantly. The lipid used to form the viral envelope consists almost entirely of cellular phospholipids synthesized before infection and phosphatidylglycerol synthesized after infection. Based on these and previously published results, a speculative model for this viral envelope formation process is presented.
Enterotoxin B formation by fermentation mutants of Staphylococcus aureus
Authors: Altenbern Robert A.
Published: April 2010

An appreciable fraction of carbohydrate-negative (car) mutants of Staphylococcus aureus strains ATCC 14458,778, and S-6 exhibit increased enterotoxin B (SEB) production. In addition, some lac and mtl mutants of these strains also display enhanced SEB formation. All such mutants appear to be point mutations. Mutagen-induced reversions of high SEB producing car, mtl, or lac mutants yield varying amounts of SEB and some clones seem to be restored to the characteristics of the parent type. A few sequentially isolated lac, mtl double mutants of strain 778 elaborate much more or much less SEB than either the lac or the mtl single mutants.
Microbial utilization of raw and hydrogenated shale oils
Authors: Westlake D. W. S. , Belicek W. , Jobson A. , Cook F. D.
Published: April 2010

The biodegradability of raw and hydrogenated shale oils prepared by a retort process were studied under psychrophilic and mesophilic conditions. Changes in bacterial numbers and the chemical composition of the oils were monitored using a plate count and chromatographic techniques respectively. Raw shale oil was found to be relatively resistant to microbial attack whereas hydrogenated shale oil was readily utilized for microbial growth. Populations enriched on raw shale oil had a reduced ability to use hydrogenated shale oil under similar conditions. Gram-negative rods predominated in all enrichment populations. It is recommended that to facilitate clean up of shale oil spills, raw shale oil be reduced at the extraction site before transport.
Properties of ribonucleic acids from photosynthetic and heterotrophic Rhodospirillum rubrum
Authors: Chow C. T.
Published: April 2010

Rifampicin causes an initial rapid breakdown of about 30% of the pulse-labeled RNA in both photosynthetic and heterotrophic Rhodospirillum rubrum. An additional degradation of RNA has been observed in the heterotrophic, but not in the photosynthetic cells at a later stage of rifampicin treatment. This secondary RNA degradation is probably caused by breakdown of ribosomal RNA, especially of the 23S species, as shown by polyacrylamide gel electrophoresis analyses. No qualitative difference between the pulse-labeled RNA species in photosynthetic and heterotrophic cells can be detected by the DNA–RNA hybridization competition technique.
Uptake and efflux of succinic acid by uninduced mycelium of Claviceps purpurea
Authors: Taber Willard A.
Published: April 2010

Claviceps purpurea PRL 1980 grew on partially dissociated succinic acid (pH 4) but not on fully dissociated succinic acid (pH 7.2). Mycelium suspended in 42 mM solution of partially ionized succinic acid (pH 4; 60.1% nonionized, 39% monoanion, and 0.9% dianion, K+ salt) over a period of 25 min accumulated more succinic acid carbon than mycelium suspended in highly ionized solution (pH 6.8; 0.01% nonionized, 4.8% monoanion, and 95% dianion). The greater accumulation from partially ionized solution was not attributable solely to metabolism of succinic acid nor to the lower external concentration of potassium ion. Rate of uptake by sodium azide and iodoacetate-treated mycelium was proportional to external concentration at least up to 200 μmol/ml. External potassium or sodium ion was not required for uptake by inhibited or uninhibited mycelium and external sodium ion and glucose did not allow concentration of succinic acid. The internal concentrations of succinic acid carbon expressed as succinic acid in cell water were about the same as the external concentrations. Uptake was not appreciably affected by extent of ionization of external succinic acid but accumulation was markedly affected. A plot of accumulated succinic acid carbon against external pH produced a bimodal curve with the two maxima corresponding to the maximal concentrations of nonionized and monoanion succinic acid. The bimodal curve probably results from overlapping of two separate curves; the nonionized form accumulating efficiently because of one interaction with the cell and the monoanion form accumulating efficiently because of another interaction. Uptake from concentrated solution is by diffusion and efflux is rapid but not complete. Efflux is not retarded by presence of phosphate in the external solution.
Characterization of a nitrogen-fixing bacterial strain from the roots of Digitaria sanguinalis
Authors: Barber Lynn E. , Evans Harold J.
Published: April 2010

Rates of nitrogen fixation of 3 to 10 g of N2 fixed per hectare per day were associated with root systems of Digitaria sanguinalis. A Gram-negative motile aerobic bacterial strain that was capable of N2 fixation was isolated from a washed root sample of one of these plants. Optimal growth and N2 fixation occurred at a pH of about 6.5, a temperature of 30–37 °C, and at a pO2 of about 0.01 atm. Increased rates of N2 fixation resulted when this strain was grown in mixed cultures with aerobic or facultative bacteria. Observations of cellular and cultural morphology and results of biochemical and physiological studies indicate that the isolate may be related to the Azotobacteraceae but that it is not identical with any of the members of this family. The importance of N2 fixation by this isolate in nature is unknown.
Toxigenic species of Penicillium, Fusarium, and Aspergillus from weevil-damaged pecans
Authors: Wells John M. , Payne Jerry A.
Published: April 2010

Of a total of 2392 fungi isolated from weevil-damaged pecans, 46.4% were Alternaria and Epicoccum, 23.9% were Penicillium, 12.4% were Pestalotia and Monochaeta, 6.5% were Cladosporium, 6.4% were Fusarium, and less than 2% each were Phoma, Aspergillus, Rhizopus, Trichothecium, and miscellaneous. Chloroform extracts of 34 of 105 representative Penicillium isolates, 3 of 28 Fusarium isolates, and 3 of 23 Aspergillus isolates were toxic to day-old cockerels during three bioassays. Eight of the toxic extracts from Penicillium spp. were tremorgenic. One tremorgenic isolate was identified as P. paxilli, four were identified as P. lanoso-coeruleum, and three as P. cyclopium. Nine of the non-tremorgenic isolates were identified as P. citrinum, five as P. aurantio-virens, three as P. oxalicum, and two as P. meleagrinum. Others were identified as one each of P. brevi-compactum (Series), P. nigricans (Series), P. roqueforti, P. rugulosum (Series), P. terrestre, and P. stoloniferium. One was unidentified. Toxigenic Aspergillus isolates were all A. flavus. Two of the toxic Fusarium isolates were F. moniliforme, and one was unidentified.
Death rates of bacterial spores: mathematical models
Authors: Han Youn W. , Zhang Hwe Ik , Krochta John M.
Published: April 2010

The concave survivor curves produced as a result of spore heterogeneity were analyzed to determine whether they were caused by innate characteristics of the spores or by the acquisition of heat resistance during the heating process. Mathematical models developed for the two hypotheses revealed that the concave survivor curve (on semi-log paper) caused by innate heterogeneity is parabolic and that caused by acquired heat resistance is exponential. The mathematical models were applied to several published survivor curves of different organisms, and heat resistance parameters and the cause of curvilinearity were determined. For the cases studied, the cause of curvilinearity appears to be acquisition of heat resistance rather than innate heterogeneity of spore population.