bluuebunny/crossref_metadata_2025 huggingface dataset:
Analogy and homology of the dehydrogenases of Oomycetes. I. Regulation of glutamic dehydrogenases and isozyme patterns
Authors: Wang H. S. , LéJohn H. B.
Published: April 2010

The NAD-specific glutamic dehydrogenase isozymes of about 50 species of the Oomycetes were examined by polyacrylamide gel electrophoresis to determine their electrophoretic properties. With few exceptions, they had similar electrophoretic properties. Six allosteric modulators, NADP+, P-enolpyruvate, GTP, ATP, UTP, and short-chain acyl-CoA derivatives that stimulate the activity of the enzyme were used as a chemical parameter to distinguish the various isozymes. A taxonomic correlation was shown to exist at the level of enzyme control, for members of the Peronosporales (Pythium spp.) were more sensitive to allosteric controls than the Saprolegniales and Leptomitales. Among the Saprolegniales, Achlya spp. were the most sensitive. Responses by Aphanomyces spp., Isoachlya spp., Protoachlya spp., and Thraustotheca spp. were weak. The two species of the Leptomitales examined were completely insensitive to the allosteric modulators. Studies with citrate as an allosteric inhibitor was restricted to the Peronosporales for this study.
Analogy and homology of dehydrogenases of the Oomycetes. III. Isozyme patterns of malic and isocitric dehydrogenases
Authors: Wang H. S. , LéJohn H. B.
Published: April 2010

The distribution and variety of isozymes of NAD-linked malic dehydrogenase, and NADP-linked isocitric dehydrogenase of 49 species of the Oomycetes was determined by slab gel electrophoresis. Only in two cases did we detect two isocitric dehydrogenase isozymes in the same species. One was Aphanomyces cladogamus, and the other Aphanopsis terrestris suggesting that these two species in different genera may have close affinity. Analysis of other enzymes from these species partially support this conclusion. In contrast, only a handful of the 49 species did not show evidence of multiple isozymic species of malic dehydrogenases. In those cases, the single isozyme activity band was rather broad which may indicate that there may be more than one enzyme species but they are poorly resolved by electrophoresis. As many as five malic dehydrogenase isozymes were found in one species of Aphanomyces. Saprolegnia delica and Aphanomyces stellatus displayed three isozymes in each case.No reliable enzyme control system has been elucidated for these enzymes, and this parameter was not used in this taxonomic study.
Fast- and slow-growing rhizobia: differences in sucrose utilization and invertase activity
Authors: Drets G. Martinez-de , Arias A. , Cutinella M. Rovira de
Published: April 2010

Growth on sucrose by 64 strains of Rhizobium was determined, and differences in the use of this disaccharide by rhizobia were established. An inducible invertase was detected in strains of the fast-growing group of Rhizobium but neither invertase nor a sucrose phosphorylase was found in strains of the slow-growing group of Rhizobium.A new evidence to consolidate enzymatically slow-growing rhizobia in a different group from the fast-growing rhizobia is presented here.
Glycerol ester hydrolase, lipase, of Myxococcus xanthus FB
Authors: Sørhaug Terje
Published: April 2010

Glycerol ester hydrolase (EC. 3.1.1.3.), lipase, in liquid cultures of Myxococcus xanthus FB released up to 200–300 neq of fatty acids per milliliter per minute. Activity was assayed by the pH-stat method. Cells alone gave 0–14% and culture growth liquor alone 0–48% of the activity of a corresponding whole culture sample. Combinations when ranked according to their levels of activity in most cases followed in this order: culture direct, addition of cells to the corresponding supernatant solution during assay, recombination of the culture fluid with the corresponding cells, and the sum of the individual activities of cells and supernatant solution. Maximal activity with tributyrin as substrate was obtained at 25C and pH 8.3. Tricaprylin was the triglyceride most rapidly hydrolyzed. The active principle did not respond as a lipoprotein lipase when judged from its behavior with effectors of these enzymes.
Degradation of 1,1-diphenylethylene by mixed cultures
Authors: Focht D. D. , Joseph H.
Published: April 2010

A nonaxenic sewage culture metabolized 1,1-diphenylethylene by two different pathways involving hydration to form 2,2-diphenylethanol and oxidation and fission of one of the benzene rings to form atropic acid. Five different bacterial strains which grew on 1,1-diphenylethylene were isolated; all were gram-negative rods comprising the genera Pseudomonas, Acetomonas, and Acinetobacter. A fungal isolate, Cladosporium, which used diphenylethylene as a sole carbon source, was also obtained from the same enrichment procedure.
Viability and pathogenicity of entomogenous fungi after prolonged storage on silica gel at −20 °C
Authors: Bell James V. , Hamalle Robert J.
Published: April 2010

Fourteen species and six strains of fungi were tested for viability after their spores had been stored on silica gel crystals in test tubes at −20 °C. Some of the fungi were maintained up to 3 years without measurable loss of viability by this method, but others could not be stored or only for a few weeks. Three insect pathogenic species, Beauveria bassiana, Metarrhizium anisopliae, and Spicaria rileyi, retained pathogenicity after 3 years storage when laboratory bioassays were conducted against host insects.
Neutralization of T-even bacteriophage: the role of tail-sheath antigen in indirect neutralization
Authors: Stemke G. W.
Published: April 2010

Characterization of an indirect, or enhanced, neutralization of T-even phage is reported. It is concluded that addition of anti-Fab, but not anti-Fcγ, converts a complex of phage and anti-phage from an infectious plaque former to a noninfectious, or neutralized, phage. It is also concluded that the antiphage involved in this indirect neutralization reacts with the T-even tail sheath, and not with the tail fibers as is the case with direct neutralization.
The cellular immune response to antigens of Coxiella burneti
Authors: Heggers John P. , Mallavia L. P. , Hinrichs David J.
Published: April 2010

Formalinized vaccines prepared from the Nine Mile, Phase I, strain of C. burneti or purified preparations of the Phase I antigen initiate a state of delayed hypersensitivity in guinea pigs as determined by the in vitro migration inhibition system. This delayed hypersensitivity is directed against the protein as well as the carbohydrate component of the Phase I antigen. Guinea pigs that had recovered from Q-fever demonstrated a similar state of delayed hypersensitivity. Circulating antibody levels as determined by the microagglutination test were readily apparent in both infected and vaccinated animals.
ICMSF methods studies. II. Comparison of analytical schemes for detection of Salmonella in high-moisture foods
Authors: Gabis D. A. , Silliker J. H.
Published: April 2010

Twenty-one naturally contaminated high-moisture food samples were analyzed to compare the relative efficiency of using thirteen 25-g, three 108.3-g, one 325-g, and one 500-g subsamples in recovery of salmonellae. In addition, recovery by preenrichment in lactose broth was compared with direct selective enrichment in selenite cystine and tetrathionate brilliant green broths. Analysis of preenriched large lumped subsamples, prepared by combining multiple 25-g subsamples, detected positive samples as effectively as the analysis of individual 25-g subsamples. In the analysis of 25-g subsamples, direct enrichment detected as many positive "lots" as preenrichment, but in the analysis of lumped subsamples, direct enrichment gave dramatically reduced recovery. Nevertheless, directly enriched 25-g subsamples resulted in a significantly lower rate of recovery than preenriched subsamples. The results indicate that analysis of a single lumped 325-g preenriched subsample is as efficient in the recovery of salmonellae as the analysis of thirteen 25-g preenriched subsamples. Further, it is apparent that preenrichment of high-moisture foods, such as meat, poultry, and eggs is to be recommended over direct enrichment for the detection of salmonellae.
ICMSF methods studies. IV. International collaborative assay for the detection of Salmonella in raw meat
Authors: Erdman I. E.
Published: April 2010

An international collaborative assay of methods for the isolation of Salmonella from raw meats showed that more positive samples were identified when enrichment broth was incubated at 43C than at 35C. The choice of enrichment broth appears to be influenced by the serotype involved. Selenite brilliant green sulfa broth was the best enrichment medium for S. schwartzengrund, S. typhimurium, and S. dublin while selenite cystine broth was best for S. senftenberg. With S. newport and S. worthington no significant difference between tetrathionate broth and selenite brilliant green sulfa broth was apparent. While bismuth sulfite agar was successful for isolations from positive samples, it gave a large number of false-positive isolates when used with Salmonella-negative samples. This did not happen with the brilliant green agars used. Best results from selective agars were obtained when laboratories were allowed to choose their own, indicating that familiarity with a medium plays a significant role in its suitability for the isolation of Salmonella.
Ultrastructure of root nodules formed by ineffective strains of Rhizobium meliloti
Authors: MacKenzie C. R. , Jordan D. C.
Published: April 2010

In three ineffective associations between Medicago sativa (alfalfa) and Rhizobium meliloti the initial stages of nodule formation, resulting in the release of the bacteria into the host cells, were found to follow the normal pattern of nodule development. In nodule tissue formed by two laboratory-produced ineffective mutants, a rapid disintegration of the invading bacteria was observed to occur shortly after the release of the bacteria into the plant cells. The disintegrating bacteria were in intimate association with large amounts of rough endoplasmic reticulum (ER). An increase in the number of mitochondria occurred at this stage as well and the peripheries of the plant cells were often lined with starch granules. Only occasionally was the stage of enclosing-membrane formation reached. In the third ineffective association, a naturally occurring one, the bacteria were transformed into the nitrogen-fixing or bacteroidal forms and were surrounded by enclosing membranes. Dissolution of the bacteria occurred at a slightly later stage in this association and was again accompanied by a buildup of rough ER. Evidence is presented to suggest that the plant response, as characterized by this ER buildup in these ineffective associations, was a manifestation of nitrogen starvation.
Production, isolation, and antimicrobial activity of hyalodendrin, a new antibiotic produced by a species of Hyalodendron
Authors: Stillwell M. A. , Magasi L. P. , Strunz G. M.
Published: April 2010

A growth inhibitor, designated hyalodendrin (C14H16N2O3S2), was isolated from liquid cultures of a species of Hyalodendron, a Hyphomycete. The isolation and production of hyalodendrin and its physical and chemical properties are described. The in vitro antimicrobial activity of this compound against a broad spectrum of fungi associated with decay and deterioration of trees and forest products was examined. Its inhibitory action against these organisms, as well as against others causing diseases in plants and trees, was found to be superior to that of the antifungal agents cryptosporiopsin, nystatin, or scytalidin. Minimum inhibitory concentrations of hyalodendrin were also established for a number of bacteria and fungi pathogenic to humans. Hyalodendrin compared favorably with benomyl in its ability to inhibit in vitro growth of Ceratocystis ulmi, the causal agent of Dutch elm disease. In seed-germination tests, hyalodendrin had a relatively low degree of phytotoxicity. Acute toxicity to mice (LD50) was established at 75 mg/kg.
The effect of sublethal heating on Staphylococcus aureus at different physiological ages
Authors: Hurst Andre , Hughes Ashton , Collins-Thompson David L.
Published: April 2010

Sublethal heat injury was measured by the difference in the numbers of colonies developing on trypticase soy agar and trypticase soy agar containing 7.5% NaCl. This difference was largest with late logarithmic and early stationary phase cells because, at this stage, cells had a greatly increased heat resistance. In contrast, the ability to form colonies on high salt agar after sublethal heating varied little during the growth cycle.
A phage-typing system for Salmonella newport
Authors: Gershman M.
Published: April 2010

A system is described for the phage typing of Salmonella newport. The system is based upon a number of bacteriophages that were isolated from local sewage plants.
The in vitro degradation of the herbicide bromoxynil
Authors: Smith Allan E. , Cullimore D. R.
Published: April 2010

The in vitro degradation of the herbicide bromoxynil at the 25 ppm level by a flexibacterium, strain BR4, was investigated. The degradation was monitored using gas-chromatographic and spectrophotometric analytical procedures. Breakdown was rapid with only 5% of the original herbicide remaining after 5 weeks. No detectable degradation occurred in sterile medium.Thin-layer chromatographic techniques were used to isolate and identify 3, 5-dibromo-4-hydroxybenzamide and 3, 5-dibromo-4-hydroxybenzoic acid as degradation products. A third metabolite was isolated but not identified.
Evidence for cellular control in the synthesis of acetoin or α-ketoisovaleric acid by microorganisms
Authors: Collins E. B. , Speckman R. A.
Published: April 2010

Commercial α-acetolactate at pH 4.5 decarboxylated nonenzymatically (5 to 8%/h) to acetoin (69%) and diacetyl (31%), and an extract of Streptococcus diacetilactis 18-16 produced α-acetolactate (in addition to acetoin and diacetyl) from pyruvate in the presence of TPP and MgSO4. Nevertheless, α-acetolactate was not dispersed into media by any of four microorganisms (S. diacetilactis, strains 18-16 and DRC1, Saccharomyces cerevisiae 299, and Lactobacillus casei 393) that produced diacetyl and acetoin or by one (Serratia marcescens) that produced only acetoin. Lactobacillus casei and S. diacetilactis 18-16 produced unknown compounds that falsely indicated the presence of α-acetolactate when tests were made without separating acetoin and diacetyl from other components of the spent media. The production of acetoin by S. diacetilactis 18-16 was not inhibited by valine, the acetoin produced by this organism was optically active (+101.0°), and a cell-free extract of S. marcescens did not produce diacetyl while producing a large amount of acetoin. Data support the conclusion that the conversion of pyruvate to acetoin by some microorganisms and to α-ketoisovaleric acid by others is enzymatic and under cellular control, resulting in the synthesis of only steady-state amounts of enzymatically bound α-acetolactate in each of the pathways.
Intracellular growth of Bdellovibrio bacteriovorus 6-5-S in heat-killed Spirillum serpens VHL
Authors: Ross E. Jeannie , Robinow C. F. , Robinson J.
Published: April 2010

If cells of Spirillum serpens (strain VHL) are heat-killed at 56C for 90 min the cells retain their original morphology remarkably well. When actively motile cells of Bdellovibrio bacteriovorus (strain 6-5-S) are inoculated into a suspension of S. serpens heat-killed at this temperature, B. bacteriovorus attacks and penetrates the dead cells, and undergoes a cycle of growth and replication similar to that which occurs in living cells. Intracellular growth of B. bacteriovorus in nonviable cells has not previously been reported.
The effect of silver ions on the respiratory chain of Escherichia coli
Authors: Bragg P. D. , Rainnie D. J.
Published: April 2010

Silver ions inhibited the oxidation of glucose, glycerol, fumarate, succinate, D- and L-lactate, and endogenous substrates by intact cell suspensions of Escherichia coli. Silver ions reacted with the respiratory chain at two levels. The site most sensitive to inhibition was located between the b-cytochromes and cytochrome a2. The second level of inhibition was in the NADH and succinate dehydrogenase regions of the respiratory chain, and was situated on the substrate side of the flavin components.
Food preservation and antibacterial properties of four fluoroalkane compounds
Authors: Auken O. W. Van , Healy J. , Kaufmann A. J.
Published: April 2010

The antimicrobial properties of trichlorofluoromethane, (Freon® 11), dichlorofluoromethane (Freon 21), and monochlorodifluoromethane (Freon 22) were tested at room temperature (22 °C) on various foodstuffs over a 12-week period. Changes in color, odor, and texture as well as precipitate formation, liquefaction, and pH were measured using samples of milk, eggs, fish, and shrimp. Dichlorofluoromethane exhibited the greatest microbial inhibition requiring 6.6 mg/ml to retard bacteria and fungal development in eggs and fish for 12 weeks, 13.1 mg/ml for shrimp, and 68 mg/ml to preserve milk. Trichlorofluoromethane was similar to dichlorofluoromethane, but monochlorodifluoromethane did not have any food preservation properties at the concentrations tested.Colony development of Streptococcus lactis was also investigated with the three previously mentioned fluorocarbons plus dichlorodifluoromethane (Freon 12). The decreasing order of inhibition of colony development was as follows: dichlorofluoromethane (Freon 21) > trichlorofluoromethane (Freon 11) = dichlorodifluoromethane (Freon 12) > monochlorodifluoromethane (Freon 22). The change in pH of S. lactis-seeded pasteurized milk was also inhibited by certain concentrations of dichlorofluoromethane.
The Pearson III function as a description of DNA synthesis and gap time distributions in bacteria
Authors: Szekely Joseph G.
Published: April 2010

The Pearson III function is suggested as a representation of the distribution of DNA synthesis and gap times. This description allows the distributions to be defined in terms of a small number of parameters, and is consistent with data on chromosome replication and division at various growth temperatures.
Ultrastructural changes in germinating ascospores of Saccharomyces cerevisiae
Authors: Steele S. D. , Miller J. J.
Published: April 2010

Ascus walls of a two-spored strain of Saccharomyces cerevisiae were shown by the freeze-etching technique to possess an outer fibrillar zone which was not observed in walls of vegetative cells and ascospores. Invaginations were less abundant in the plasmalemma of the spore protoplast than in that of the vegetative cell. Those in the latter were, however, less elongate. The walls of buds produced by germinating spores were continuous with the spore wall and the mechanics of bud formation appeared similar in spores and vegetative cells. Buds produced by spores resembled the spore in possessing thick walls and in containing abundant lipid granules. The transition to typical vegetative cells with thin walls and sparse lipid deposits required several cell division cycles. Bud scars on asci could be observed clearly with the scanning electron microscope.
Distribution of hydrocarbon-utilizing bacteria in Northwestern Atlantic waters and coastal sediments
Authors: Mulkins-Phillips G. J. , Stewart James E.
Published: April 2010

An extensive survey was carried out to aid in understanding the role of indigenous microorganisms in the removal of oil from Northwestern Atlantic temperate to arctic marine environments. The presence of hydrocarbon-utilizing microorganisms was demonstrated in sediments and adjacent waters taken from Bermuda, Canadian Northwest Atlantic and Eastern Canadian Arctic marine shorelines. In addition, surface-water samples (5 m depth) taken at 11 different stations along a transect between Halifax and Bermuda, with one exception, showed the presence of significant numbers of hydrocarbon-utilizing microorganisms. The hydrocarbon-utilizing bacteria present included Nocardia, Pseudomonas, Flavobacter, Vibrio, and Achromobacter species. The fraction of the total heterotrophic bacteria represented by the hydrocarbon utilizers ranged up to 100% depending upon the area's previous history of oil spillage; the bulk of the values were less than 10%. The frequency of specific hydrocarbon utilization in decreasing order was hexadecene-1, pristane, hexadecane, dibenzothiophene, anthracene, and decalin. The location, numbers, variety, and broad capacity of the microbial hydrocarbon utilizers illustrate their ubiquity and indicate the microbial potential for removal or conversion of oil in the environments examined.
Growth of the haploid and diploid phases of Physarum flavicomum in the same partially defined media
Authors: Henney Jr. Henry R. , Asgari Mortaza , Henney Mary R.
Published: April 2010

The haploid phase (myxamoebae-swarm cells) of the myxomycete Physarum flavicomum variety 1 grows readily in partially defined liquid media, which were developed for the culture of the diploid plasmodial phase. Cell yields of between 2 × 107 and 4 × 107 cells/ml are obtained in these media in aerobic shake culture. Growth rates are more rapid in shake culture than in stationary culture but growth does not occur in anaerobic conditions. The simpler of the two media contains salts, glucose, biotin, thiamine, hematin, and casein hydrolysate. Haploid cells consume about half as much oxygen per milligram protein per hour as the diploid microplasmodia growing in the same medium.
Hormone-induced differentiation of antheridial branches in Achlya ambisexualis: dependence on ribonucleic acid synthesis
Authors: Horowitz David K. , Russell Peter J.
Published: April 2010

Sexual differentiation in male strains of the aquatic fungus Achlya ambisexualis Raper is induced by antheridiol, a sexual steroid hormone secreted by female strains. Antheridiol-induced initiation of the morphologically distinct antheridial branches in male Achlya is completely prevented when DNA-dependent RNA synthesis is inhibited by actinomycin D. In addition antheridial branch elongation is inhibited to a degree proportional to the concentration of actinomycin D added. Thus, evidence indicates that RNA synthesis is required for antheridiol-induced initiation of antheridial branching and that continued RNA synthesis is required for elongation of antheridial branches.
The characterization of a Bacillus capable of blue-green bactericidal activity
Authors: Reim Richard L. , Shane Miriam S. , Cannon Robert E.
Published: April 2010

A gram-negative, aerobic, spore-forming Bacillus isolated from a sewage oxidation pond was found to have a lytic effect on a wide variety of blue-green bacteria and on several bacteria, including other bacilli. The isolate, designated 247, has been identified as an atypical Bacillus brevis. The lytic activity was found in the culture filtrate and was produced during the stationary phase of growth. When the culture filtrate was applied to the interaction between Plectonema boryanum and LPP-cyanophages, it facilitated the establishment of lysogeny by these viruses.
Experimental adiaspiromycosis in rabbits. Evaluation of protoplasmic proteins and Sephadex G-100 fractions as specific antigens
Authors: Cano Raul J. , Taylor John J.
Published: April 2010

Laboratory rabbits experimentally infected with aerosolized conidia of Chrysosporium parvum or C. parvum var. crescens were skin-tested with partially purified protoplasmic protein (P) antigens extracted from the fungi, and with several components of P antigens separated by Sephadex G-100 fractionation. Ten micrograms of conidial or 5 μg of adiaspore P antigen produced delayed type skin responses only in those animals infected with the homologous strain. Large quantities of antigens elicited skin reactions in both homologously and heterologously infected rabbits. Skin-reactive components of P antigens were either strain-specific or non-specific, and were recovered from aleuriospores, or adiaspores, or from both. One strain-specific fraction (21) recovered from both aleuriospores and adiaspores may merit clinical and (or) epidemiological trial as a skin-test antigen.
Yeasts occurring in the effluent disposal basins of a pulp mill in Saskatchewan
Authors: Spencer J. F. T. , Gorin P. A. J. , Gardner N. R.
Published: April 2010

The numbers of yeasts in the effluent disposal system of the Prince Albert, Saskatchewan Pulp Mill occasionally reached 1 × 106 cells/liter, but were usually below 5 × 105 cells/liter. Rhodotorula species were commonly isolated and sometimes amounted to half of the population, though usually the relative numbers were considerably lower. The highest counts were found in late summer and early autumn. Bacterial counts varied from 20 × 106 to 74 × 106 cells/ml. Chemical O2 demand (COD) reached about 1200 mg/liter at times, and decreased as the effluent moved through the disposal system, about 40% of the total COD being removed during the treatment process. A considerably wider range of yeast species was found in the pulp mill disposal basins than in the Saskatoon sewage treatment plant. Most of the ascosporogenous yeasts found were Hansenula or Pichia species usually occurring in association with trees, as were many of the Candida species isolated.
Isolation and characterization of pigmentation mutants of Micrococcus roseus
Authors: Schwartzel E. H. , Cooney J. J.
Published: April 2010

A number of UV-induced pigmentation mutants of Micrococcus roseus were isolated. The carotenoid pigment composition of a yellow mutant and a pink mutant were determined and compared with the composition of the wild type. The yellow mutant appeared to have the ability to insert oxygen functions on only one end of β-carotene. The pink mutant formed less total carotenoids than the wild type; it formed diketo-carotenoids but no dihydroxy compounds. The results are discussed in relation to xanthophyll synthesis in M. roseus.
Action of light on Micrococcus roseus
Authors: Schwartzel E. H. , Cooney J. J.
Published: April 2010

Micrococcus roseus is killed by exposure to a continuous spectrum of white light (3000 ft-c (32 292 lm/m2)) in the presence of air and the dye, toluidine blue. Comparison of rates of photodynamic killing for log and stationary phase cells and for two pigmentation mutants indicated that photosensitivity could not be correlated with amount of carotenoid or with carotenoid-chromophore length. Moreover, cells grown in medium containing diphenylamine (DPA) did not contain significant quantities of colored carotenoids; they were not as sensitive to photodynamic killing as fully pigmented cells. Photodynamic killing was accompanied by selective release of magnesium and calcium and by release of UV-absorbing material. In the absence of added photosensitizer, M. roseus, the two mutants, or DPA-inhibited cells were not killed when exposed to white light at intensities as high as 22 000 ft-c (236 806 lm/m2) for as long as 9 h, and cells did not release UV-absorbing material. Under these conditions M. roseus and the yellow mutant did not release as much magnesium or calcium as when subjected to photodynamic killing, but DPA-grown cells leaked sodium, magnesium, and calcium. These observations are consistent with several suggestions: (i) carotenoids do not serve as photochemical buffers in M. roseus; (ii) growth in medium containing DPA or mutations leading to altered pigmentation change membrane organization leading to altered photosensitivity; (iii) M. roseus has an efficient repair mechanism which renders it resistant to photodynamic killing unless an exogenous photosensitizer is present.
Proteinaceous hexagonal inclusions in hyphae of Whetzelinia sclerotiorum and Neurospora crassa
Authors: Hoch H. C. , Maxwell D. P.
Published: April 2010

The chemical nature of the hexagonal inclusions occurring in microbodies of Whetzelinia sclerotiorum and in the cytoplasm of Neurospora crassa was investigated. These inclusions were considered to be ergosterol or protein. The major β-3-hydroxyl-sterol present in W. sclerotiorum was identified as ergosterol. When glutaraldehyde (GA) fixed hyphae of both W. sclerotiorum and N. crassa were treated with sterol-extracting solvents, the hexagonal inclusions were still observed in thin sections. Sodium methoxide treatment of thin sections of hyphae fixed with GA and OsO4 removed the lipid bodies, but not the hexagonal inclusions. Various proteases, subtilisin, Sigma protease type VI, and pepsin, digested the inclusions from thin sections of hyphae fixed only with GA. Inclusions in thin sections of hyphae fixed with 2% KMnO4 were extracted by 1.0 N NH4OH, 0.1 M Na3PO4, or 0.16 N NaOH (about pH 12), but not by 0.16 N NaOH adjusted to pH 8.8 with HCl. These results indicate that the hexagonal inclusions in W. sclerotiorum and N. crassa are primarily proteinaceous in nature and are similar in composition to the Woronin bodies observed in other Ascomycetes.
Denitrifying bacteria in some shallow-water marine sediments: enumeration and gas production
Authors: Patriquin D. G. , Knowles R.
Published: April 2010

Trace amounts of nitrous oxide in enrichment cultures, detected by gas chromatography, indicate the presence of much higher numbers of denitrifiers in marine sediments than are indicated by production of gas in inverted vials.
Failure to induce autoimmune disease with neonatal bursectomy in chickens
Authors: Mahouy G. , Holliday Jean , Box P. G. , Perey D. Y. E. , Barnes R. D.
Published: April 2010

To assess the effect of abnormal control of bursa-derived B cell function upon the development of spontaneous autoimmune disease, newly hatched chicks were surgically bursectomized or sham-bursectomized and studied up to 4 months of age. The presence of autoimmune disease was assessed by direct Coombs' test, measurement of antinuclear antibody, total hemoglobin, packed cell volume, plasma bilirubin, red cell survival, and immunofluorescence studies on frozen kidney sections. Despite abnormal immunoglobulin levels detected in bursectomized chickens, no significant differences in terms of autoimmune activity could be demonstrated between the two groups. This suggests that primary B cell control is an unlikely factor in the etiology of autoimmune disease and supports earlier studies which imply that a major factor leading to progressive autoimmune disease is the failure of a normal T cell suppression function.
Microbiological and chemical enrichment of freshwater-surface microlayers relative to the bulk-subsurface water
Authors: Hatcher Roger F. , Parker Bruce C.
Published: April 2010

Concentrations of bacteria, fungi, ammonium, nitrate, nitrite, orthophosphate, sulfate, and certain metals were enriched in freshwater-surface microlayer samples relative to the bulk-subsurface water. Results differed markedly depending on which of three methods for surface-microlayer collection was used. This report suggests that the biologically and chemically rich freshwater-surface microlayers contribute to ecological functions and interactions between subsurface water and the atmosphere not heretofore investigated in freshwater.
Improved procedure and colorimetric test for the detection of ortho- and meta-cleavage of protocatechuate by Pseudomonas isolates
Authors: Ottow J. C. G. , Zolg W.
Published: April 2010

A sensitive and clear-cut method for the demonstration of ortho- and meta-cleavage of protocatechuate is described. Pseudomonas strains to be tested for the mode of ring fission should be grown on a synthetic medium containing p-hydroxybenzoate, quinate, or glucose–yeast extract as sole carbon source. Suspensions of these organisms are tested for ring-fission mechanism to detect the constitutive or inducible nature of protocatechuate 3,4-oxygenase.
Interferon-mediated increased lysis of L-cells by vesicular stomatitis virus
Authors: Katz L. J. , Lee S. H. S. , Rozee K. R.
Published: April 2010

L-929 cells have been cultivated for more than 6 months in the presence of interferon. These L-cells, referred to as L-int cells, were found to be more susceptible to the lytic properties of vesicular stomatitis virus (VSV) than normal L-929 cells. This phenomenon has been demonstrated by the production of clear plaques as opposed to cloudy plaques as well as the increased release of cell incorporated 3H-thymidine after VSV infection. The L-int cells were also signicantly more susceptible than L-929 cells to the cytotoxic properties of DEAE-dextran, protamine sulfate, and methylated albumin.This interferon-induced change to L-cells is not stable. Increased susceptibility to VSV lysis is lost after 4–6 cell generations in the absence of interferon, and increased susceptibility to DEAE-dextran is lost after 16–24 cell generations in the absence of interferon. Moreover, the increased sensitivity to VSV lysis and polycation cytotoxicity can be induced after overnight treatment of L-929 cells with interferon.
Avantages et inconvénients de l'acétate d'uranyle en virologie comparée: étude de quatre bactériophages caudés
Authors: Ackermann Hans-W. , Jolicoeur Pierre , Berthiaume Laurent
Published: April 2010

Effects of uranyl acetate (UA) and potassium phosphotungstate (KPT) on dimensions of four tailed bacteriophages have been studied comparatively. All UA stained preparations show positive (UA+) or negative (UA−) staining according to the local, low- or high-particle concentration, and crystals containing swollen, distorted phages. UA causes flattening or shrinking of phage heads, the latter especially after positive staining. Transverse diameters of elongated heads are reduced, and capsids, tails, and tail fibers may be swollen. In addition, isometric heads may show pentagonal outlines and tails may be elongated. Dimensions of phages TP50 and PBP1 have been analyzed by the method of multiple discriminant analysis. Differences between KPT, UA−, and UA+ stained viruses are statistically highly significant (P < 0.001). Dimensions of UA+ stained viruses appear to be unreliable for taxonomic purposes. Dimensions of UA− stained viruses are to be controlled by other staining methods. UA has several advantages but phosphotungstate stains should be preferred, particularly in staining large cubic DNA viruses.
The effect of complement and other cell wall reagents on tetracycline and streptomycin resistance in Pseudomonas aeruginosa
Authors: Tseng J. T. , Bryan L. E.
Published: April 2010

Lysozyme-free antiserum and complement treatment of strain 1885 of Pseudomonas aeruginosa was observed to destroy the penetration barrier of the outer cell wall to lysozyme but not to induce leakage of acid-soluble nucleotides through the cell membrane. The same treatment did not produce a significant increase in uptake of 3H-tetracycline or 3H-streptomycin by the resistant strain 1885 in spite of the destruction of the penetration barrier to lysozyme. A significant increase in both streptomycin and tetracycline uptake occurred in carbenicillin-treated strains but the increase was similar for both susceptible and resistant (to tetracycline and streptomycin) strains of P. aeruginosa. These data suggest (1) the outer cell wall is not a significant penetration barrier to these drugs; (2) the peptidoglycan layer does function as a penetration barrier of similar magnitude in resistant and susceptible cells; (3) the resistance of the strains is a property of the cell membrane or materials intimately associated with the cell membrane. The latter conclusion was further supported by the differential uptake of streptomycin in NaCl-lysozyme-induced spheroplasts of strains 1885 and 2379.
Utilization of amino acids as nitrogen sources, and their effects on nitrate reductase in the marine diatom Cyclotella cryptica
Authors: Liu Ming Sai , Hellebust Johan A.
Published: April 2010

Several amino acids supplied at 0.1 mM allow good growth of Cyclotella cryptica. The cells can grow as well on arginine and glutamine as on nitrate. Glutamate, proline, ornithine, and asparagine also allow good growth, while glycine, alanine, and aspartate support relatively low initial growth rates. Isoleucine appears not be utilized at all. Ammonium and urea are excellent nitrogen sources for growth.There is good correlation between chlorophyll and protein content in cells grown on different nitrogen sources. Cells grown in nitrate, arginine, and glutamine media contain the highest amount of protein and the best pigmentation. Although both glutamate and proline allowed good growth, cells grown in these media have low levels of protein and chlorophyll, indicating nitrogen limitation. No growth inhibition was observed for any of the amino acids tested at 0.1 mM in the presence of nitrate. It is estimated that amino acids at naturally occurring concentrations may contribute significantly to the nitrogen economy of this diatom when more common nitrogen supplies such as nitrate and ammonia are scarce.Nitrate reductase in C. cryptica appears to be found only in the presence of nitrate, and is repressed by other nitrogen compounds. The extent of repression by amino acids, urea, and ammonium is related to their ability to promote growth when supplied as sole sources of nitrogen.
Purification of urease by affinity chromatography. II. Further studies on matrix characteristics, ligand specificity, and adsorbent capacity
Authors: Shobe Charles R. , Brosseau J. D.
Published: April 2010

The synthesis of alternative adsorbents and their attempted use for the purification of urease from jack bean extracts and from several strains of Proteus morganii by affinity chromatography is described. The nature of the ligand and the length of the side chain joining the ligand to the agarose backbone of the matrix were critical factors in determining the suitability of these adsorbents for urease purification. Adsorbent capacities continued to be the only factor limiting the purification of urease by this method from any of the sources so far used.
Inhibition of Pseudomonas pseudomallei by carbenicillin, in vitro
Authors: Franklin Mervyn
Published: April 2010

The activity of carbenicillin (CB) on 20 strains of Pseudomonas pseudomallei was determined by the agar-diffusion and tube-dilution methods. Under the conditions of the tube-dilution method oxygen diffusion limited the growth of this obligate aerobe and KNO3 (0.1%) was added to the assay medium as an alternate electron acceptor. The range of minimal inhibitory concentrations (MIC) for the strains studied was 50 μg/ml, 100 μg/ml, and 200 μg/ml. Thus, 17 of the 20 strains had MIC's below the blood level of CB achievable in vivo (in excess of 100 μg/ml). Activity of CB declined in the presence of heavy inocula and early logarithmic phase cells were more sensitive to CB than stationary phase cells. Variation in incubation temperature or electron acceptor availability caused changes in the MIC.Survival curves of P. pseudomallei in the presence of CB (at the minimal bactericidal concentration (MBC)) indicated a loss of colony-forming units at a rate of 1 log per 1.75 h. The increase in OD of P. pseudomallei cultures in the presence of CB was found to be due to filament formation.
Development of a cellular body during differentiation of conidial chlamydospores in Fusarium
Authors: Schneider Edward F. , Seaman W. L.
Published: April 2010

The development of cellular bodies during the conversion of conidial cells to chlamydospores in Fusarium sulphureum (F. sambucinum f.6) is described. Development of the bodies from dilated cisternae within the endoplasmic reticulum begins before there are other recognizable changes in cell structure and is completed before new cell wall material is laid down. Each body is bounded by a single membrane derived from the endoplasmic reticulum and contains electron-dense particles, vesicular structures, and usually a microbody. These components remain intact within the body until a late stage in chlamydospore development. At that time the contents become granular, the vesicles and microbodies disappear, and the body becomes vacuole-like. A similar body was found in cells of Fusarium poae at comparable stages of chlamydospore development.
Haloprogin: mode of action studies in Candida albicans
Authors: Harrison E. F. , Zygmunt W. A.
Published: April 2010

The relative antifungal properties of haloprogin, a new synthetic antimicrobial agent, and two polyene antibiotics, amphotericin B and nystatin, were determined in Candida albicans. The specific parameters studied included possible effects on (i) cell viability, (ii) oxygen utilization, (iii) uptake and incorporation of labelled leucine and uridine, and (iv) loss of intracellular K+ ions. Susceptibility of mammalian erythrocytes to lysis by these antimicrobial agents was also determined. Fungicidal activity of haloprogin appears to be attributable to inhibition of oxygen uptake and disruption of the cell membrane. Haloprogin affects protein and nucleic acid synthesis to a lesser degree as evidenced by uptake and incorporation of labelled precursors. The two polyene antibiotics act in a different manner; nystatin effectively inhibits oxygen utilization and incorporation of leucine and uridine, whereas amphotericin B affects primarily leucine incorporation. Both polyene drugs disturb the cell membrane as shown by intracellular loss of potassium ions from C. albicans cells and lysis of mammalian erythrocytes.
Effect of butterfat on inhibition of Staphylococcus aureus by nisin
Authors: Jones L. W.
Published: April 2010

Nisin in brain heart infusion medium (Difco) and Bacto-Staphylococcus medium 110 completely inhibited the growth of Staphylococcus aureus 196. This restraining action of nisin on S. aureus was not as effective in the presence of whole milk. This was especially noted when attempts were made to control growth of S. aureus in cheese made with starter inactivated by phage. Although nisin had some inhibitory action on S. aureus in cheese it was not equal to that exerted by an active Streptococcus lactis culture. Its presence failed to prevent production of enterotoxin A. A factor influencing the failure of nisin to control growth of S. aureus in cheese was the presence of butterfat which was shown to interfere with the action of nisin against the growth of S. aureus.
The effects of various water-sample treatments on the apparent uptake of glutamic acid by natural marine microbial populations
Authors: Griffiths R. P. , Hanus F. J. , Morita R. Y.
Published: April 2010

The apparent glutamate utilization by natural marine microbial populations was shown to be greatly influenced by the method used to terminate the uptake reaction. There was a significant difference in the amount of labeled material associated with the microorganisms when treated with either acid or buffered formaldehyde before the sample was assayed. A comparison of the data collected from acidified and nonacidified water samples resulted in significant differences in the following calculated values: percentage respired, the maximum velocity of uptake (Vmax), the turnover time (Tt), and the transport constant and natural substrate concentration (Kt + Sn). The rates of radioactivity incorporation into CO2 and acidified and nonacidified cells were followed with time and were found to be nonlinear after extended incubation.Data is presented which indicate that the labeled material that is released during acidification is that associated with the glutamate pool. The effects of these observations on the interpretation of data collected during heterotrophic potential studies are discussed.
Purification and properties of RNA polymerases I and II from germinated spores of Rhizopus stolonifer
Authors: Gong Cheng-Shung , Etten James L. Van
Published: April 2010

RNA polymerases I and II were purified several hundredfold from germinated spores of the mycelial fungus, Rhizopus stolonifer. Three major subunit proteins with estimated molecular weights of 180 000, 104 000, and 32 000 daltons were obtained from RNA polymerase I and four major subunit proteins with estimated molecular weights of 215 000, 114 000, 37 000, and 27 000 daltons were obtained from RNA polymerase II. Therefore, the molecular structures of RNA polymerases I and II from R. stolonifer are essentially similar to those purified from other eukaryotic organisms.
Inhibition of Pythium ultimum in molecular fractions from gel filtration of soil extracts
Authors: Vaartaja O.
Published: April 2010

Filtered samples of aqueous extracts from clay and sandy soils (pH 5 to 6, Ontario) were fractionated using Sephadex and Bio-Gel. Responses of extension growth to the fractions were bioassayed with mycelia of Pythium ultimum Trow. Of 66 samples, 48% contained 1, or often several fractions that fully or partly inhibited growth; 5% contained stimulatory fractions; and 9% contained fractions with both inhibitory and stimulatory action; in 38% all fractions were without significant effects (at p < 0.01). Of 12 samples that in toto failed to exhibit, 4 nevertheless contained inhibitory fractions; this suggested a counteraction of inhibition by either stimulatory or nonstimulatory substances. Counteraction in several extracts was demonstrated with 36 fractions that were bioassayed both in purified agar (all 36 inhibited) and in agar amended with 0.5% yeast extract and 5% sucrose (only 1 inhibited). Estimations of the approximate molecular weights of the inhibitors showed that there were many different inhibitors, most of these (74%) with molecular weights between 3000 and 55 000. The results are considered as direct evidence for non-volatile inhibitors contributing to mycostatic situations in soils.
Reversal of filament formation in the psychrophile Bacillus insolitus
Authors: Ferroni G. D. , Inniss W. E.
Published: April 2010

When filamentous cells of Bacillus insolitus, formed by incubation at 30C, were incubated at 20C, a resumption of cross-wall formation occurred. Reversal of the inability to divide did not occur when de novo protein synthesis was prevented by chloramphenicol, or when D-cycloserine, vancomycin, or penicillin was present. Resumption of septation did take place in the presence of nalidixic acid.
The microbial degradation of cyclohexanecarboxylic acid: a pathway involving aromatization to form p-hydroxybenzoic acid
Authors: Blakley E. R.
Published: April 2010

A strain of Arthrobacter catabolizes cyclohexanecarboxylic acid by a pathway involving aromatization of the ring before its cleavage. The pathway includes the following intermediates: trans-4-hydroxycyclohexanecarboxylic acid, 4-ketocyclohexanecarboxylic acid, p-hydroxybenzoic acid, protocatechuic acid, and β-ketoadipic acid. The oxidation of 4-hydroxycyclohexanecarboxylic acid by cell extracts specifically requires NAD+ and results in the production of 4-ketocyclohexanecarboxylic acid. The latter compound is oxidized in the presence of a suitable electron acceptor, such as oxygen, methylene blue, or 2,6-dichlorophenolindophenol, to p-hydroxybenzoic acid.
The novel structure of a microorganism of human gingival plaque
Authors: Halhoul Nagi , Colvin J. Ross
Published: April 2010

Electron-microscopic examination of gingival plaque microflora showed a bacillus-like, microencapsulated, thick-walled organism with a previously unreported structure. This structure, which is not an example of fimbriae, flagellae, or attached extracellular polysaccharide, is a tuft of thin fibers about 0.3 μm long at only one end of the cell. The fibers begin in or near to the cell wall and pass through the microcapsule to the outside. The name lotussy is proposed for this new structure and the name lotuslifa for an individual fiber or filament.