bluuebunny/crossref_metadata_2025 huggingface dataset:
Overproduction of hisH and hisF gene products leads to inhibition of cell division in Salmonella
Authors: Murray Michael L. , Hartman Philip E.
Published: February 2010

Salmonella typhimurium derepressed for the histidine biosynthetic enzymes form wrinkled colonies at 37 °C on media containing a high (2%) content of metabolizable carbon source. "Wrinkledness" reflects accumulation of multinucleate filamentous cells caused by impaired cell division. At 42 °C, DNA synthesis and nuclear division are impaired. Addition of methionine at 42 °C permits DNA synthesis, nuclear division, and, under some conditions, cell division. However, multinucleate filaments are formed both on high and on low carbon source at 42 °C. The filaments contain nuclei that are peculiarly hypersensitive to inactivation with ultraviolet (uv.) light.Overproduction of both the hisH and hisF gene products is required for these pleiotropic effects of derepression. The hisH and hisF proteins, and even some of their enzymologically inactive forms, may cooperate to inhibit cell division by direct interaction with (a) sensitive cellular site(s).
The occurrence of pyruvic acid ketal in a glucan from a fungus, Microsporum quinckeanum
Authors: Fielder R. J. , Grappel S. F. , Bishop C. T. , Blank F.
Published: February 2010

A glucan containing 0.6% of pyruvic acid has been isolated from the mycelium of Microsporum quinckeanum. Methylation studies on the native glucan and on a depyruvated sample, proved that the pyruvic acid was present as a ketal and probably as a 4,6-ketal (4,6-O-1-carboxyethylidene) attached to nonreducing terminal units in the polysaccharide. The native glucan was capable of eliciting immediate-type cutaneous-hypersensitivity reactions in guinea pigs sensitized by cutaneous infection with M. quinckeanum and reacted with homologous antiserum but gave no reaction with type XXVII pneumococcal antiserum that contained antibodies directed towards the pyruvic ketal.
The organisms and biological processes involved in asymbiotic nitrogen fixation in waterlogged soil amended with straw
Authors: Rice W. A. , Paul E. A.
Published: February 2010

The acetylene reduction assay was used to determine nitrogenase activity in a waterlogged soil–straw system. Nitrogenase activity was related to the number of nitrogen-fixing Clostridia. The patterns of respiration, microbial numbers, and nitrogenase activity indicated a change in the microbial activity at about the 8th day of incubation. This was attributed to the sequential use of the different straw components, with a short lag in activity between the periods of maximum hemicellulose and cellulose utilization.Two layers of microbial activity were observed in waterlogged soil–straw mixtures, an aerobic layer extending from the surface to a depth of 2 mm, and an anaerobic layer below this. The organisms in the aerobic layer were responsible for the partial degradation of straw and the release of metabolites; the metabolites were used by the nitrogen-fixing organisms in the anaerobic layer.Anaerobic organisms of the genus Clostridium were found to be the only active nitrogen fixers in the waterlogged systems. The physiological and morphological characteristics of the organisms isolated from the waterlogged soil are similar to those of C. butylicum.
Interaction of interferon with cells: the relationship between interferon uptake and activity
Authors: Stewart Robert B. , Sheaff Edward T.
Published: February 2010

The antiviral activity of interferon was found to be related to the amount of interferon that became cell-associated. Reduction in the amount of interferon uptake by cells by sulfhydryl-binding compounds (p-chloromercuribenzoate and N-ethylmaleimide) reduced the level of antiviral activity of the cells. Interferon, inactivated by heat or trypsin did not affect the ability of active interferon to induce an interferon uptake system. Trypsin-inactivated interferon was, however, shown to compete with active interferon for the interferon uptake system while heat-inactivated interferon was without effect.
Immunological patterns of "typical" and Runyon's group I mycobacteria determined by cytoplasm antigens
Authors: Kwapinski J. B. G. , Alcasid Alice
Published: February 2010

Cytoplasm preparations were obtained from 30 different strains of typical or Runyon's group I mycobacteria. Immunological activities of the cytoplasms were examined with immune globulins of cytoplasm antisera by an immunodiffusion test on cellulose–acetate membranes. Patterns of immunological activity of the cytoplasms were found to be relatively simple. Six different serogroups of the mycobacteria have been distinguished by the presence of one or two characteristic antigenic factors in the cytoplasm. The cytoplasm serogroups correlated with the cultural types and species designations. The serogroup and serotype chart was recommended for immunological identification and differentiation of the typical and group I mycobacteria.
Comparison of the kinetics of thiosulfate oxidation by three iron–sulfur oxidizers
Authors: Bounds Harold C. , Colmer Arthur R.
Published: February 2010

The sulfur metabolism of Thiobacillus ferrooxidans, Ferrobacillus ferrooxidans, and Ferrobacillus sulfooxidans was found to differ in the rate of utilization of thiosulfate and tetrathionate, with tetrathionate showing the most significant difference between the three organisms. The apparent Km values of the three organisms ranged from 2–5 × 10−2 M for T. ferrooxidans and F. sulfooxidans to 5–7 × 10−3 M for F. ferrooxidans. Increasing the temperature caused a greater effect on thiosulfate oxidation by F. ferrooxidans than with the other two as shown by the apparent Ea values (Ea′ for F. ferrooxidans, 18 000; F. sulfooxidans, 11 400; T. ferrooxidans, 11 000).The initial pH of the medium determined the rate of thiosulfate oxidation. If the initial pH was 4.0–4.5, a sharp break in oxygen uptake was shown by T. ferrooxidans and F. sulfooxidans after 20–30 min, but not with F. ferrooxidans.When the disappearance of thiosulfate and tetrathionate from the medium was used as an indicator of the affinity of the three test organisms for the sulfur compounds, F. ferrooxidans demonstrated the highest net loss of both compounds from the medium.
Bunyamwera virus replication in mosquitoes
Authors: Peers R. R.
Published: February 2010

After intrathoracic injection of 3.2 dex Bunyamwera (BUN) virus into groups of wild caught Aedes vexans and A. canadensis, increments of infectivity were first detected in salivary glands and gut at 3 days and maximum titers of 5.2 dex per organ were attained in the salivary glands at 10 days. Virus transmission by mosquito bite was demonstrated in suckling mice 10 days after the mosquitoes were injected, but not after shorter intervals. Virus replication was not demonstrable after the ingestion of 4.0 dex in a blood meal.Aedes aegypti mosquitoes readily supported the replication of BUN virus following injection with 3.3 dex or imbibing of 4.6 dex. After injection virus titers of whole mosquitoes declined to 1.7 dex at 12 h, followed by a peak of 5.2 dex at 4 days. After feeding, virus was first detected in the hemolymph and salivary glands at 4 days and attained maximum titers of 5.0 dex in salivary glands at 10 days. Transmission of virus to mice was accomplished 10 days after feeding, but not earlier.Enveloped viruses with 45 nm cores and 80 to 120 nm external diameter were observed within vacuoles and lining vacuolar membranes of salivary glands and gut cells of A. aegypti mosquitoes 10 days or more after infection with BUN virus. The dimensions and appearance of these particles correlated well with those of virions seen in chick embryo fibroblasts during the peak of the BUN virus infection cycle.
Effect of guanidine on the growth of LSc poliovirus
Authors: Tershak D. R. , Mitchell W. , Garfinkle B.
Published: February 2010

The presence of 3 mM guanidine between the 2nd and 4th h of the poliovirus growth cycle results in a 4-h delay in viral growth, rather than the anticipated 2-h delay. For the first 90 min after removing guanidine the rate of synthesis of viral RNA is the same at both 35C and 39C. This is characteristic of the first 2 h of standard infection and suggests that a second latent period occurs after removal of inhibitor. However, the second latent period is not completely new because infective centers are very resistant to uv. light immediately after guanidine treatment. This shows that viral products synthesized during the initial latent period are used following guanidine treatment. The use of products that were formed before guanidine treatment can account for the accelerated rates of synthesis of viral RNA, viral polymerase, and viral protein that were also observed.
Further studies on tumor-specific immunity induced by nontumorigenic mouse ascites tissue-culture cells
Authors: Eng C. P. , Morgan J. F.
Published: February 2010

Long-term tissue cultures derived from the TA3 ascites tumor of the mouse became nontransplantable but induced a high degree of immunoprotection against challenge with as many as 106 virulent cells. Intraperitoneal immunization proved more effective than the intravenous or intramuscular routes. After chemical and physical treatments virulent TA3 cells showed no immunoprotective capacity. After similar treatments the nontumorigenic TA3 tissue-culture cells showed a moderate immunoprotective capacity. Nontumorigenic cells of the 6C3HED and TA3 lines induced a high degree of immunoprotection against solid tumor development produced by the subcutaneous injection of as many as 107 virulent cells. Protection against solid tumor development could be demonstrated provided immunization with nontumorigenic cells was begun within 2 weeks of implantation of the virulent cells.
Isoniazid metabolism and binding by sensitive and resistant strains of Mycobacterium smegmatis
Authors: Fishbain David , Ling George , Kushner Donn J.
Published: February 2010

Suspensions of Mycobacterium smegmatis in buffer broke down isoniazid (INH) after a lag period and produced equivalent amounts of isonicotinic acid (INA). Smaller amounts of hydrazine were formed. If chloramphenicol (CAP) was added at the beginning of the incubation, INH did not disappear nor did INA or hydrazine appear. However, if CAP was added after INH had started to disappear, the fall in INH and the appearance of INA were the same as in the absence of CAP, and more hydrazine was formed. Sensitive and resistant cells caused similar reactions, except that the former produced somewhat more hydrazine. These results, and others with toluene-treated cells, suggest that INH is broken down by at least two induced enzymes, one of which splits INH to INA and hydrazine, and a second enzyme(s) which changes hydrazine to an unknown product. Lowering the incubation temperature slowed metabolic changes. Glycerol increased the rate of INH breakdown. Cyanide and azide inhibited breakdown. Azide had a much greater effect on INH-sensitive than on INH-resistant cells. Sensitive cells bound about twice as much radioactivity from 14C-labeled INH as resistant cells. Effects of temperature, metabolites, and inhibitors on binding were also studied. These experiments show that INH does not act as an inhibitor of protein synthesis or mRNA synthesis in sensitive cells and that resistant cells are permeable to INH, even though they bind less of the drug than sensitive cells.Isoniazid-sensitive and resistant strains were about equally susceptible to the growth-inhibitory action of hydrazine and hydroxylamine. Neither was inhibited by INA. During incubation of sensitive cells with INH in growth media very small amounts of hydrazine were formed, insufficient to inhibit growth. Resistant cells grew in the presence of INH without destroying significant amounts of it. Apparently INH itself, and not a metabolic product, is the inhibitory substance. Resistance does not depend on INH destruction.
On the heterogeneity of staphylococcal enterotoxin C2
Authors: Dickie N. , Yano Y. , Robern H. , Stavric S.
Published: February 2010

Isoelectric focusing of purified staphylococcal enterotoxin C2 revealed the presence of as many as eight immunologically identical protein fractions in a pH 5–8 ampholyte system with pI (isoelectric point) values of 7.35, 6.95, 6.75, 6.55, 6.20, 5.95, 5.70, and 5.50, respectively. In refocusing experiments, fractions of the toxin were found to arise by conversion from a more basic protein fraction.
Comparison of the immunological properties of two canine adenoviruses
Authors: Marusyk R. G.
Published: February 2010

By means of immunological methods, including neutralization (NT), neutralization-enhancement (NE), hemagglutination-inhibition (HI), as well as immunodiffusion experiments, the two known canine adenoviruses, infectious canine hepatitis (ICH) virus and infectious canine laryngotracheitis (ICL) virus, have been shown to be two distinct serotypes. The relationship between the two viruses was shown to be predominantly one-sided as ICH hexon antisera could neutralize ICL virus infectivity to a much higher extent than the reciprocal cross-reaction. The one-way cross-reaction was also found to involve the fiber components as demonstrated in HI tests with fiber-specific antisera and virions and soluble components as antigens. In contrast, NE tests with fiber-specific antisera were found to be type-specific. A HI test using virion antisera and soluble complete hemagglutinin as antigen was found to be a rapid and specific method for distinguishing between the two virus types. The specificity of this HI test was interpreted to be based on the presence of type-specific antibodies against the vertex capsomere (penton base). Immuno-diffusion precipitin analyses substantiated the data obtained in the preceding experiments, as spur formation in two directions was found when fiber antisera was tested against purified fiber. Precipitin patterns obtained with purified hexon and hexon antisera indicated a unique determinant associated with the ICL hexon, presumably the type specificity detected in the hexon antisera NT tests. On the basis of data obtained in this and previous studies on the relationship of the two canine adenoviruses, it is proposed that ICL virus be officially recognized as a distinct canine adenovirus serotype.
Preparation of spheroplasts from Streptococcus lactis
Authors: Kruse H. , Hurst A.
Published: February 2010

Stationary phase cells of Streptococcus lactis resisted lysis by lysozyme under a variety of test conditions, although they lost 20% of their hexosamine. Lysozyme was bound by the cells and caused the optical density of the suspensions to rise. Incubation of the cells (0.5 mg dry weight/ml) in buffer with lysozyme (1 mg/ml), NaCl (0.5 M), or sodium dodecylsulfate (0.1%) caused prompt lysis. The cells were stabilized with 10% polyethylene glycol but not by 10–30% sucrose. Lysozyme and NaCl-treated cells in polyethylene glycol were spheroplasts because they were osmotically fragile, lost their shape but retained a rhamnose wall polymer. The spheroplasts retained all the DNA of the original cells, and 10% of the original numbers could be cultured on agar. However, they lost all their muramic acid and 60% of their hexosamine. In contrast to NaCl, sodium dodecylsulfate-treated cells were killed.
The formation of rhizopterin and formylated folate polyglutamates during the growth of Staphylococcus epidermidis
Authors: Martin E. L. , Koft B. W.
Published: February 2010

The distribution of various folate forms during the growth of Staphylococcus epidermidis is described. Cellular-free folate activity (pteroate-like substances and mono- and di-glutamate folates) was quite prevalent in the early and mid-log phase of growth, but subsequently reached a minimal level in the stationary phase of growth. This free folate activity was identified as rhizopterin, with an extremely small amount of folic acid per se also being found. Cellular polyglutamate folates (folate conjugates with three or more glutamic acid units) were found in relatively high amounts throughout growth, and for any cellular sample constituted most of the total folate activity. The polyglutamate folate compounds were identified as formylated derivatives. A biosynthetic pathway from rhizopterin to the formylated polyglutamate folates is proposed.
Physiological and morphological effects of phenethyl alcohol upon a gram-negative marine pseudomonad
Authors: Thompson J. , DeVoe I. W.
Published: February 2010

Phenethyl alcohol (PEA) at 0.15% (v/v) inhibited the growth of a gram-negative marine pseudomonad. After removal of the alcohol, the cells remained viable even when pre-exposed to PEA concentrations as high as 0.25% (v/v). Phenethyl alcohol inhibited uptake of α-aminoisobutyric acid (AIB) and also prevented amino acid exchange. At PEA concentrations of 0.25% or less, inhibition of AIB uptake was completely reversible and, provided K+ was added to the uptake medium, the treated cells could accumulate AIB to the same extent as control cells. If K+ was omitted from the medium, the capacity of the cells to accumulate AIB was found to be proportional to the length of time that the cells had been exposed to the alcohol. Phenethyl alcohol caused a rapid efflux of intracellular K+ and AIB-14C from previously loaded cells, and such cells were noticeably smaller than normal cells and had a plasmolyzed or irregular outline when observed by phase contrast. Thin section electron microscopy, and freeze-etch studies, showed that the plasmolyzed appearance of these cells was due to local invagination of the cytoplasmic membrane. After removal of the alcohol, the subsequent addition of K+ to the incubation medium caused the cells to become deplasmolyzed. It seems likely that the inhibition of cell growth by PEA is due to two major causes: (1) direct interference of the compound with the normal physiological functions of the cytoplasmic membrane and, (2) PEA induced structural changes occurring within the cell envelope.
Characteristics of an aminopeptidase activity from the cultural fluid of Bacillus subtilis
Authors: Ray Lee E. , Wagner Fred W.
Published: February 2010

An aminopeptidase activity of the cultural fluid of Bacillus subtilis readily hydrolyzed L-leucyl-β-naphthylamide after preincubation with Co(NO3)2. Numerous other divalent metal ions did not activate the enzyme toward LNA but were found to inhibit enzyme activation by cobalt ions. Other aminopeptidase substrates were hydrolyzed by the native enzyme, cobalt activated native enzyme and cobalt, or zinc activated EDTA-treated enzyme. The aminopeptidase activity of cultural fluids was stable at 70° for at least 2 h; however, EDTA-treated enzyme was not stable under identical conditions. Reactivation of EDTA-treated enzyme with cobalt or zinc ions restored partial and complete heat stability, respectively, while calcium reactivated enzyme was heat labile. Enzymatic activity toward LNA substrate was lost on the removal by dialysis of excess cobalt ions indicating that metal ions play at least a bifunctional role, one relating to structural stability and one relating to enzymatic activity.
Purification and characterization of glutamic acid dehydrogenase and α-ketoglutaric acid reductase from Peptococcus aerogenes
Authors: Johnson W. M. , Westlake D. W. S.
Published: February 2010

Two NAD-dependent enzymes involved in glutamic acid metabolism have been isolated from cell-free extracts of P. aerogenes. One enzyme, glutamic acid dehydrogenase, was shown to oxidatively deaminate glutamic acid yielding α-ketoglutaric acid in the presence of NAD but not NADP. The other enzyme, an NADH-requiring α-ketoglutarate reductase, reduced the α-keto acid to α-hydroxy-glutarate. The two NAD-dependent enzymes were separated, purified, and characterized. The results indicate that glutamic acid dehydrogenase, an enzyme not frequently implicated in anaerobic glutamate metabolism, is a predominating protein in extracts of P. aerogenes grown in the presence of glutamate. Kinetic data showed that the equilibrium of the latter reaction favored the direction of keto acid reduction.
A study of thermophilic aerobic sporeforming bacteria isolated from soil and water
Authors: Harris O. , Fields M. L.
Published: February 2010

Thirty-three strains of thermophilic aerobic sporeforming bacteria isolated from soil and water were studied by classical determinative bacteriological methods and by % guanine + cytosine (% GC) in the DNA. The cultures fell into two groups based upon % GC. There were 12 strains with % GC of 52–53.1 which were characteristic of Bacillus stearothermophilus. These strains were also classifiable as B. stearothermophilus by classical determinative bacteriological methods except three were aciduric. The other 21 strains had % GC ranging from 38.8 to 43.9 with a mean % GC of 42.04. Ten strains of the 21 could be B. coagulons by classical determinative bacteriological methods but not by % GC. The other 11 strains were not determinable by current classical determinative keys. These strains may be thermophilic variants of mesophilic species.
The production of D-glycero-D-manno-heptitol by Torulopsis versatilis
Authors: Onishi Hiroshi , Perry M. B.
Published: February 2010

Torulopsis versatilis cultivated in the presence of lactose produced D-glycero-D-manno-heptitol. This is the first report of the production of this heptitol by microbial fermentation.
Cinnamylphenols as inhibitors of fungal growth
Authors: Dupuis G. , Johri B. , Bandoni R. J. , Towers G. H. N.
Published: February 2010

Cinnamylpyrogallol was found to be a greater inhibitor of fungal growth than either cinnamyl alcohol or pyrogallol. Antifungal activity decreased with time owing to oxidation of the compound in solution. Cinnamylphloroglucinol was less active than cinnamylpyrogallol against the 27 species of fungi (including dermatophytes) tested. In addition these substances also were active against two of the four bacterial species tested.
An evaluation of rhodamine-labeled lysozyme as a fluorescent stain for in situ soil bacteria
Authors: McElroy L. J. , Casida Jr. L. E.
Published: February 2010

Rhodamine-labeled lysozyme, in conjunction with fluorescein isothiocyanate conjugated to gelatin as a counterstain, was evaluated as a fluorescent stain for resident soil microorganisms. Preparations were observed by light-diffraction microscopy, transmitted incandescent-light microscopy, and reflected ultraviolet-fluorescence microscopy using a modified light-diffraction microscope, and by conventional transmitted incandescent and ultraviolet-fluorescence microscopy. Laboratory-grown microbial cultures superimposed on the resident soil microflora, as well as the non-dormant resident soil microorganisms, usually fluoresced properly when the stain and counterstain were applied to soil, and the blocking test with non-conjugated lysozyme was effective. What were assumed to be semidormant cells fluoresced to a lesser degree, and the blocking test was only partially effective. In contrast, the dormant resident soil microorganisms usually did not become stained by the methods used. A possible explanation is that a peripheral structural component surrounding many of the resident dormant cells in soil may have rendered their cell-wall substrate inaccessible to the enzyme conjugate.
Induced morphological changes in the stainable layers of the cell envelope of a gram-negative bacterium
Authors: Costerton J. W. , Thompson J.
Published: February 2010

Manipulation of ion concentration can be used to produce profound changes in the morphology of both the cytoplasmic membrane and the outer double-track layer of the cell envelope of the marine pseudomonad studied here. The fact that these layers are deformable, without any changes in the morphology of the rigid peptidoglycan layer, suggests that both have a "plastic" physical nature.
DNA base composition and the taxonomy of the Oomycetes
Authors: Green Beverley R. , Dick Michael W.
Published: February 2010

The DNA base compositions of seven members of the Saprolegniaceae were determined by cesium chloride (CsCl) gradient centrifugation. In general, base composition data correlated with morphological classification, but in several cases it indicated the necessity for revisions. In particular, Achlya inflata (eccentric group) was 42% guanine–cytosine (GC), while A. racemosa, A. sparrowii, and A. colorata (racemose group) were 51–52% GC.Two isolates of Saprolegnia diclina and one of S. parasitica were 58–59% GC and all contained 10–20% of a lighter density satellite DNA.Analysis of thermal denaturation curves by a modification of De Ley's method (J. Theoret. Biol. 22: 89 (1969)) showed that as little as 7.4% GC difference represents a large difference in DNA sequence homology. Therefore, base composition data by itself can provide a rigorous aid to the classification of the oomycetous fungi at the generic level.
The state of binding of intracellular K+ in Halobacterium cutirubrum
Authors: Lanyi Janos K. , Silverman Melvin P.
Published: February 2010

Intracellular K+ in lysed freeze-thawed cell pastes of the extreme halophile, H. cutirubrum, diffused readily against a concentration gradient during equilibrium dialysis, whereas the intracellular Mg2+ was not readily diffusible. The K+ activity in the lysed cell pastes, determined directly by K+ ion-specific electrode, was comparable to the total K-content of the cells, as determined by atomic absorption. This finding and the results of the dialysis experiment suggest that the intracellular K+ in H. cutirubrum is not bound.
The fine structure and development of chlamydospores of Fusarium oxysporum
Authors: Stevenson I. L. , Becker S. A. W. E.
Published: February 2010

Methods have been developed for the rapid, reproducible induction of high-density populations of F. oxysporum chlamydospores. On transferring washed pregerminated conidia to a simple two-salts medium, chlamydospore morphogenesis was evident by 12 h and masses of mature spores could be harvested at the end of 4 days. Electron-microscope studies of thin sections of mature chlamydospores reveal a thick triple-layered cell wall. The cytoplasm contains, in addition to large lipid deposits, a nucleus, mitochondria, and endoplasmic reticulum all typical of fungal cells. Chlamydospores of F. oxysporum exhibit two distinct types of cell surface in thin section. The outer wall layer of two of the isolates studied was smooth-surfaced while the outer layer of the two other isolates was distinctly fibrillose. Some evidence is presented suggesting that the fibrillose material arises through the partial breakdown of the original hyphal wall.
Extracellular neuraminidase of Streptomyces albus
Authors: Myhill Marjory K. , Cook Thomas M.
Published: February 2010

Extracellular neuraminidase activity (mucopolysaccharide N-acetylneuraminylhydrolase, EC.3.2.1.18) was detected in culture filtrates of Streptomyces albus MA-390, S. albus NCTC 7807, and S. albidoflaviis, but not S. albus ATCC 3004, S. roseochromogenes ATCC 13400, or S. venezuelae ATCC 10595. Neuraminidase of S. albus MA-390, purified 430-fold from crude culture filtrates, cleaved N-acetylneuraminyllactose and released thiobarbituric acid-reactive material from various glycoproteins. With excess substrate the reaction rate was proportional to enzyme concentration. The enzyme was not stimulated by divalent metal ions and was not inhibited by ethylenediaminetetraacetate. Streptomyces albus MA-390 neuraminidase was heat labile and activity was lost rapidly at temperatures of 40°C and above. With N-acetylneuraminyllactose as substrate optimal activity occurred at pH 6.0, but with fetal bovine serum the pH optimum was 3.5. The molecular weight of the enzyme was estimated by gel filtration to be in the range of 40 000 to 45 000.
Lipid biosynthesis during the recovery of Salmonella typhimurium from thermal injury
Authors: Tomlins Richard I. , Vaaler Gloria L. , Ordal Z. John
Published: February 2010

The heating of Salmonella typhimurium 7136 at 48C produced a sublethal injury. When injured cells were placed in fresh growth medium, they recovered within 3 h their normal tolerance to Levine Eosin Methylene Blue Agar containing 2% NaCl (EMBS). An isotope dilution assay demonstrated that 26.6% of the total lipid extracted from recovered cells was synthesized during the recovery period. Phospholipids synthesized during growth or recovery comprised about 90% of the total lipid. The concentrations of phosphatidyl ethanolamine and phosphatidyl glycerol synthesized during growth or recovery were similar; however, the amount of cardiolipin synthesized during recovery was greater than that obtained from normal cells. The fatty acid species synthesized during recovery were qualitatively similar but quantitatively dissimilar to the fatty acid profile of normal cells. The decreased concentrations of cyclopropane fatty acids with concomitant increases in their parent monoenoic acids gave presumptive evidence for the partial inactivation during injury of the enzyme cyclopropane fatty acid synthetase.
Enterovirus recovery from laboratory-contaminated samples of shellfish
Authors: Konowalchuk Jack , Speirs Joan I.
Published: February 2010

A sensitive and reproducible method for the recovery of enterovirus from the supernatant fluids of centrifuged homogenates of laboratory-contaminated shellfish meats is described. These fluids contain varying amounts of toxic materials that interfere with coxsackievirus B5 recovery in HEp-2 cells. Most of the cytotoxicity can be removed by precipitation with hydrochloric acid at a pH of 3.0–3.5. The acid-treated samples are diluted 1:4 in fetal bovine serum and then mixed with cell suspensions in plastic dishes to adsorb the virus particles which are subsequently enumerated as plaques. The method is applicable to oysters, mussels, and clams but especially the last two because of the high cytotoxic levels of these shellfish. Other methods of concentrating sample volumes are also examined as a means of detecting enteroviruses from naturally contaminated shellfish.
Extracellular cephalosporinases produced by gram-negative bacilli
Authors: Mildvan Donna , Hirschmann Shalom Z. , Meyers Burt R. , Keusch Gerald T.
Published: February 2010

Seventy-five strains of nine species of gram-negative organisms were tested for susceptibility to cephapirin, a new cephalosporin antibiotic, and 23% were found to be resistant. Two of the resistant organisms, an Escherichia coli and a Serratia marcescens, consistently produced cephalosporinase in their filtrates. The E. coli filtrates produced by 109 organisms per milliliter were much more active than those produced by an equal number of S. marcescens. The activity of the S. marcescens filtrate was destroyed by heating at 65 °C for 15 min while that of the E. coli filtrate required heating at 100 °C for 15 min for inactivation. The molecular weight of the filtrate cephalosporinase was estimated to be 10–30 000 daltons by membrane-filtration techniques. The Km for cephapirin inactivation by the cephalosporinase of the S. marcescens filtrate, at its pH optimum of 7, was 49 nanomolar. The extracellular cephalosporinases were active against cephapirin, cephalothin, cephaioridine, and penicillin G at the same dilutions of the filtrates.
Closed-loop intestinal obstruction in Candida albicans monocontaminated rats
Authors: Yale Charles E. , Balish Edward
Published: February 2010

Closed-loop intestinal obstruction, with and without hemorrhagic or ischemic strangulation, was studied in germ-free rats individually contaminated with one of three strains of Candida albicans. The principal findings were (a) C. albicans monocontamination of the unoperated germ-free rat was innocuous; (b) contamination of the segment, alone, was as lethal as contamination and strangulation; (c) monocontamination of the closed segments, with and without strangulation, with either strain NIH 792 or ATCC 10261 killed over 30% of the animals although ATCC 10259 had no obvious effect; and (d) ATCC 10261 was associated with late postoperative intestinal bleeding and death. Ancillary findings in a group of C. albicans monocontaminated, but unoperated, germ-free rats were (a) there were rather uniform concentrations of viable C. albicans throughout the gastrointestinal tract; and (b) the serum proteins of these animals showed increased levels of total protein, alpha-2, and beta, but not gamma globulins, in comparison to germ-free rats.
Production of pectolytic and macerating enzyme by Phoma strasseri
Authors: Melouk Hassan A. , Horner Chester E.
Published: February 2010

Pectolytic enzyme activity of P. strasseri was highest in filtrates from cultures 5 and 23 days old, as determined by reducing-groups assay (RGA). Pectolytic enzyme activity, as determined by viscosity-reduction assay (VRA), was highest in cultures 7 days old. Macerating enzyme activities were highest in cultures 10 days old. Young peppermint-rhizome sections were more susceptible to maceration by P. strasseri filtrates than older sections. Colored phenolic compounds were released from macerated rhizomes and amounts released were correlated with degree of maceration.Differential inhibition of pectolytic enzyme activity (as judged by VRA and RGA assays) by a range of phenolic compounds suggests that at least two pectolytic enzymes capable of hydrolyzing α-1,4 linkages of pectic substances are produced by P. strasseri.Highest activities of pectolytic and macerating enzyme in extracts from diseased rhizomes were detected 5 days after inoculation with P. strasseri. Extracts from healthy rhizomes did not show pectolytic and macerating enzyme activity.Healthy peppermint-rhizome tissues had higher activities of polyphenoloxidase than diseased tissues; also, polyphenoloxidase activities in inoculated rhizomes decreased as time of incubation increased.
A chemically defined medium for Treponema strain PR-7 isolated from the intestine of a pig with swine dysentery
Authors: Smibert Robert M. , Claterbaugh Jr Raymond L.
Published: February 2010

The nutrition of treponeme strain PR-7 isolated from the intestinal tract of a pig with swine dysentery was studied. The organism fermented arabinose, xylose, maltose, cellobiose, glucose, galactose, mannose, lactose, pectin, and starch. The end products of fermentation of glucose were major amounts of succinic acid, moderate amounts of acetic and formic acid, and a trace of lactic acid and ethanol.Strain PR-7 required glutamate, aspartate, proline, leucine, methionine, arginine, valine, alanine, serine, lysine, glycine, threonine, isoleucine, phenylalanine, tyrosine, histidine, tryptophan, glutamine, asparagine, and spermine. The organism also required nicotinamide, folic acid, pyridoxal, thiamine, riboflavin, pantothenate, choline, α-lipoic acid, and biotin. The fatty acids isobutyrate, n-valerate, acetate, and pyruvate were needed as well as ammonium sulfate. A fermentable energy source such as glucose was necessary for growth, as well as carbon dioxide. Heme was also required and the organism was stimulated by vitamin B12, ascorbic acid, ornithine, and para-aminobenzoic acid. Heme could be replaced by catalase, myoglobin, and peroxidase.Ten other treponemes that were isolated from the intestines of normal pigs as well as from pigs with swine dysentery and had phenotypic characteristics similar to strain PR-7 grew in the defined medium.
The significance of pattern variations in pyocine typing of Pseudomonas aeruginosa
Authors: Chadwick Paul
Published: February 2010

Sequential isolates of Pseudomonas aeruginosa from 57 infected sites in 54 patients were pyocine-typed on agar plates containing mitomycin C, by a method depending on inhibition of indicator strains by pyocines produced by the test strains. The inhibition pattern remained constant for cultures from 28 infected sites. In the remaining 29, both predominant and variant patterns could be identified. Many variant patterns differed from the predominant one only to the extent of one indicator strain. Each of two commonly occurring predominating patterns varied characteristically from the other pattern. It was suggested that minor variations in inhibition pattern reflect instability of either pyocine production or pyocine susceptibility of the indicator strains, whereas major variations in pattern signify independent infections.
Effect of nitrilotriacetic acid on growth and mating in strains of Escherichia coli K-12
Authors: Stine Gerald J. , Hardigree Alice A.
Published: February 2010

The effect of nitrilotriacetic acid (NTA), a possible substitute for phosphates in detergents, was studied on strains of Escherichia coli K-12. No mutagenic effect was observed, but inhibition of growth and recombinant formation with increasing concentrations of NTA occurred. Nitrilotriacetic acid also induced abnormal cell morphology and yellow pigmentation in colonies.
Effect of hyperbaric atmospheres on β-galactoside transport in Escherichia coli
Authors: Daily O. P. , Schlamm N. A.
Published: February 2010

The rates of transport of two β-galactosides by whole cells of Escherichia coli were elevated by pressurization to 68 atm with helium or helium–oxygen gases. Kinetic analyses showed that the high atmospheric pressure caused an increase in Vmax values of some 20 to 48% whereas Km values were unchanged.
Degradation of rutin by Aspergillus flavus. Quercetinase: isolation of a low molecular-weight form containing less carbohydrate
Authors: Oka T. , Simpson F. J.
Published: February 2010

Previous work indicated that quercetinase (a flavonol 2,4-dioxygenase) is a glycoprotein with a molecular weight of 111 000 ± 4000 and containing 27.5% carbohydrate. However, a form having a molecular weight of about 80 000 and containing only 4.7% carbohydrate was recovered from two different batches of enzyme that behaved in an anomalous manner on purification. The conditions responsible for bringing about the separation of the carbohydrate moiety from the enzyme appear to result from the combined effect of high salt concentrations on drying in vacuo followed by chromatography on Sephadex G-100. Both forms were enzymatically active, had the same isoelectric point, were similarly affected by inhibitors, and equally stable towards denaturation by heat. The carbohydrate moiety thus is not an integral part of the enzyme.
Nutritional basis for relating Prototheca and Chlorella
Authors: Pore R. Scott
Published: February 2010

Prototheca, which has been referred to as an achlorophyllous Chlorella, is now for the first time associated nutritionally with Chlorella protothecoides. Prototheca spp. and C. protothecoides share a requirement for thiamine and lack the ability to assimilate nitrate. This provides circumstantial evidence that Prototheca and C. protothecoides are related and excludes the other morphologically similar Chlorella.
Isolation and characterization of n-butane-utilizing microorganisms
Authors: McLee A. G. , Kormendy Agnes C. , Wayman M.
Published: February 2010

Fifteen bacterial strains and four molds capable of growth on n-butane were isolated and partially classified. The bacteria were mostly Arthrobacter sp. and Brevibacterium sp.; among the molds, Penicillium nigricans, Allescheria boydii, and Graphium cumeiferum were identified, while the remaining mold had the appearance of Gliocladium, but was not firmly identified. Although able to grow on other alkanes and orthodox media, the bacterial isolates could not use methane. Growth rates on n-butane were unaffected by varying air or substrate partial pressures in the range of 10–90% atmosphere. High partial pressure of oxygen was inhibitory to most bacterial isolates, the degree of inhibition varying widely, however. Growth rates on n-butanol and on glucose were significantly higher than those on n-butane. Among the molds, only the Graphium would grow well in submerged, shaking culture.
The immunology of cytoplasmic antigens of mycobacteria
Authors: Kwapinski J. B. G. , Alcasid Alice , Kwapinski Elke H. , Nairn V.
Published: February 2010

Cytoplasms obtained from 220 strains of mycobacteria were examined against immunoglobulin preparations obtained from 70 cytoplasm antisera by an immunodiffusion technique. The data, arising from 60 000 individual tests, were computed and correlated with the pathogenicity and cultural characteristics revealed in a new semisynthetic medium.Pathogenic mycobacteria were recognized by the antigenic patterns a, ab, ac, abc, bc, or bq whereas the main determinants in non-pathogenic mycobacteria were found to be the e, f, g, k, l, m, and t determinants. Nine major cytoplasmic serogroups, eight tentative serogroups, and seven new cultural groups of mycobacteria were distinguished. A comprehensive chart presenting immunological relationships and differentiation of the mycobacteria was presented and a procedure for a combined immunological and cultural recognition of potentially pathogenic strains of mycobacteria was outlined.
Microbial conversion of p-hydroxyphenylacetic acid to homogentisic acid
Authors: Blakley E. R.
Published: February 2010

An unidentified bacterium degrades p-hydroxyphenylacetic acid by a pathway which involves homogentisic acid as an intermediate. Extracts of cells grown on p-hydroxyphenylacetic acid contain an enzyme that converts p-hydroxyphenylacetic acid to homogentisic acid. The enzyme has been partially purified by ammonium sulfate fractionation and some of its properties examined. The complete oxidation of 1 mole of p-hydroxyphenylacetic acid requires 1 mole of either NADH or NADPH, and 1 mole of oxygen, and results in the production of 1 mole of homogentisic acid. The enzyme preparation has a high specificity for p-hydroxyphenylacetic acid, but has about 25% activity with p-hydroxyphenylpyruvic acid.
Influence of phenylacetic acid on poly-β-hydroxybutyrate (PHB) polymerization and cell elongation in Azotobacter chroococcum Beij.
Authors: Nuti M. P. , Bertoldi M. de , Lepidi A. A.
Published: February 2010

The influence of phenylacetic acid on the polymerization of β-hydroxybutyrate and cell elongation in Azotobacter chroococcum has been investigated.The polymer was extracted by a new method. Its molecular weight, calculated by intrinsic viscosity and light-scattering, was about 300 000 for control cells and increased to 330 000 for cells treated with phenylacetic acid. The dispersivity of the polymer was clearly influenced by phenylacetic acid.As shown by electron microscopy, the existence of a membrane surrounding the granules of poly-β-hydroxybutyrate (PHB) was confirmed; cell wall structures, cell membrane, and mesosomes appeared not to be damaged by the treatment with phenylacetic acid, and also the formation of the septa was not influenced; on the contrary, the cells growing in the presence of phenylacetic acid were more lengthened than the control ones (average length of 7.1 μ against 2.7 μ).
Electron microscopical characterization of newly isolated Rhizobium lupini bacteriophages
Authors: Lotz Wolfgang , Mayer Frank
Published: February 2010

Eight strains of Rhizobium lupini bacteriophages newly isolated from compost soil were studied in the electron microscope. The phage particles investigated had either long contractile, long non-contractile, or short non-contractile tails. The wedge-shaped appearance of short phage tails is discussed.
Purification and properties of 6-phosphogluconate dehydrogenase from Penicillium duponti and Penicillium notatum
Authors: Miller Hugh M. , Shepherd Maxwell G.
Published: February 2010

6-Phosphogluconate dehydrogenase was isolated and partially purified from the thermophilic fungus Penicillium duponti and the mesophilic fungus Penicillium notatum. The specific activities of the purified enzymes were 17.5 and 22.0 respectively. Optimal activity was obtained at pH 8.0 for both enzymes. Non-linear Arrhenius plots were found for both enzymes with breaks at 30 °C for P. duponti 6-phosphogluconate dehydrogenase and 19 °C for P. notatum 6-phosphogluconate dehydrogenase. The thermal inactivation of 6-phosphogluconate dehydrogenase from both fungi exhibited first order kinetics, and the rate of inactivation for the thermophilic enzyme between 25 °C and 45 °C was only 25% that of the mesophilic enzyme. 6-Phosphogluconate dehydrogenase from both sources was protected from thermal inactivation by 6-phosphogluconic acid, high salt concentration, and high protein concentration. The thermophilic enzyme was found to be more resistant to the denaturants urea, acetamide, and sodium dodecylsulfate.
Immuno-electron microscopy of herpes simplex virus
Authors: Rigby C. , Johnson C. M.
Published: February 2010

A quantitative method for immuno-electron microscopy (IEM) of herpes simplex virus (HSV) is described which is based on comparative particle counts of residual, free virions remaining in suspension after the incubation of HSV virus suspensions with antiserum. This method has been used for the characterization of those antigens of the viral nucleocapsid and envelope which reacted with selected rabbit hyperimmune and human convalescent antiserum. The presence of viral-specific antigens in the nucleocapsid and the envelope was demonstrated by agglutination reactions with the rabbit anti-viral sera used; host antigens could not be detected. One antigen of the viral envelope reacted with rabbit hyperimmune antisera, but not with human convalescent serum; the possible significance of this antigen is discussed.
Lysosomes and the "toxicity" of Rickettsials. III. Response of L cells infected with egg-attenuated C. psittaci 6BC strain
Authors: Kordová Nonna , Poffenroth Linda , Wilt John C.
Published: February 2010

During the infection of L cells (clone 60 and 929) with egg-grown C. psittaci 6BC strain, lyosomes retained their integrity and L cells were not injured. Infected cells proliferated more intensely and showed higher mitotic indices from 24 h post infection than noninfected control cells. Chlamydial inclusions were released from the cytoplasm of infected L cells by pseudopodia-like extrusions. These events were in marked contrast to the effect of the L cell grown C. psittaci 6BC strain which caused activation of lysosomal acid phosphatase and damage of L cells. Previous comparative studies of the host lysosomal response to egg-grown as compared to cell culture grown C. psittaci 6BC strain in cultured macrophages and L cells are discussed.
An examination of Penicillium notatum for the presence of Penicillium chrysogenum-type virus particles
Authors: Volkoff Olga , Walters Teresa , Dejardin Rosamund A.
Published: February 2010

Virus-like particles have been shown to be present in all strains of Penicillium chrysogenum examined but not in penicillin producing strains of P. notatum. Attempts to "cure" P. chrysogenum of the virus infection were not successful, nor was it possible to infect P. notatum with the purified virus from P. chrysogenum. Examination of longitudinal sections of the mycelia of P. chrysogenum showed that the virus particles are enclosed in vesicles in the infected cells.
The utilization of L-tryptophan as nitrogen source by Fusarium culmorum, Aspergillus nidulans, and Penicillium italicum
Authors: Coll J. , Leal J. A.
Published: February 2010

Fusarium culmorum reached a maximum dry weight of 60 mg/25 ml, and indolelactic acid (ILA) was found in the culture filtrates during the first 8 days of incubation. Only traces of ILA were detected in the filtrates of Aspergillus nidulans and none in those of Penicillium italicum both of which reached a dry weight of about 90 mg/25 ml.
Immunogenicity of a soluble membrane antigen from adenovirus-12 induced tumor cells demonstrated in inbred hamsters (PD-4)
Authors: Hollinshead Ariel , McCammon James R. , Yohn David S.
Published: February 2010

A soluble antigen was isolated from the cell-membrane fraction of a transplantable adenovirus-12 tumor which had been induced and carried in inbred hamsters for more than 4 years. In this same inbred strain, an immunizing dose–response relationship was determined. As little as 60 μg of the soluble antigen, Ad-12 tumor-specific transplantation antigen (TSTA) given intraperitoneally without adjuvant led to protection of about 50% of challenged hamsters. A single intraperitoneal injection of 90 to 120 μg of Ad-12 TSTA protein, with or without adjuvant, led to protection of inbred hamsters to an inoculum of Ad-12 tumor cells which yielded tumors in 80 to 90% of nonimmunized hamsters. Immunized hamsters did not resist a challenge of 104 SV40-induced tumor cells.