摘要:

Changes in dry weight, hydrogen cyanide production, peroxidase, and soluble proteins of mycelium of a low-temperature basidiomycete with age of cultures were studied.Hydrogen cyanide was detected only after there was a decrease in growth of mycelium as determined by dry-weight measurements. Polyacrylamide gel electrophoretic analyses showed that the pattern and numbers of peroxidase and other soluble-protein bands varied with the age of the culture. Concomitant with decreases in yield of mycelium, there was a decrease in the numbers of peroxidase and soluble-protein bands.

ISSN:0008-4166    

DOI:10.1139/m68-196

出版商:NRC Research Press    

年代:1968

数据来源: NRC

摘要:

Endotoxins from Gram-negative bacteria were dissociated by sodium lauryl sulfate (SLS). Evidence for dissociation was disappearance of a rapidly sedimenting component after endotoxin was mixed with SLS and the formation of hybrids between antigenically different endotoxins mediated by SLS. Pyrogenicity, however, was not reduced in parallel with dissociation of the endotoxin. Also, plasma did not reduce the pyrogenicity of SLS-dissociated endotoxin as it did with endotoxin dissociated by sodium deoxycholate. It is theorized that failure of the SLS-dissociated endotoxin subunits to react with plasma factors prevents a demonstrable reduction in pyrogenicity of the preparation.

ISSN:0008-4166    

DOI:10.1139/m68-197

出版商:NRC Research Press    

年代:1968

数据来源: NRC

摘要:

Algal populations were studied in soils from sites representing several major forest types ranging from the spruce–fir forests in the Appalachian Mountains to the Southern pine forests along the Atlantic Coast. In addition, the nitrogen-fixing blue-green algal population of a forest tree nursery was examined.The results of this investigation indicate a general lack of nitrogen-fixing algae in acid forest soils. However, a pronounced development of these algae was observed in the acid nursery soil, especially on the soil surface. Low numbers of algae were found in some forest soils but only when the soil was above pH 5.4. No nitrogen-fixing Cyanophyceae were isolated from soils in the Appalachian Mountains regardless of soil acidity.Nostoc muscorumwas the most common nitrogen-fixing species occurring under both forest and nursery conditions.Nostoc communewas isolated only from the nursery soil. Several strains ofNostoc ellipsosporumwere obtained from a mixed hardwood–softwood site. An examination of the algal flora of a number of Alaskan tundra soils gave results similar to those found in the forest soils.

ISSN:0008-4166    

DOI:10.1139/m68-198

出版商:NRC Research Press    

年代:1968

数据来源: NRC

摘要:

The object of this study was to reevaluate speciation ofPropionibacteriumby using numerical taxonomy. Fifty-six cultures representing eight species were studied. Thirty-eight morphological and physiological features were employed in the calculation of matching coefficients which were used to sort the cultures into groups. The results suggest a need for species consolidation; for example,Propionibacterium shermaniicould appropriately becomeP.freudenreichiivar.shermanii. Close resemblances were found betweenP.rubrum,P.peterssonii, andP.jensenii.Propionibacterium arabinosumandP.pentosaceumformed another mutually similar group. Further studies using additional cultural, physiological, serological, genetic, and phage host-range characteristics should be instituted to establish an improved classification of propionibacteria.

ISSN:0008-4166    

DOI:10.1139/m68-199

出版商:NRC Research Press    

年代:1968

数据来源: NRC

摘要:

The growth of 29 agarolytic marine bacteria was studied in several complex and defined liquid screening media as well as with four amino acids alone and in combination with galactose and NH4Cl. Thirteen cultures were selected for response to other carbon sources, including a variety of carbohydrates and Krebs cycle intermediates.Results indicated that the nutrition of all cultures was "simple"; i.e., single amino acids were utilized with galactose and other carbon compounds replaced galactose. In general, the agarolytic bacteria tested showed a diverse ability to utilize monosaccharides, although growth levels were less than in complex media. Only two cultures responded to Krebs cycle compounds.Some ecological aspects are discussed.

ISSN:0008-4166    

DOI:10.1139/m68-200

出版商:NRC Research Press    

年代:1968

数据来源: NRC

摘要:

A potent toxin was extracted from a natural population of the blue-green alga,Aphanizomenon flos-aquae. The toxin is thermo- and acid-stable; alkaline labile; soluble in water and ethanol; insoluble in acetone, ether, and chloroform; and readily dialyzable. Preliminary studies show that the alga contains a toxin which, when released from lysed cells, operates at the membrane level, destroying excitability without alteration of the transmembrane resting potential.

ISSN:0008-4166    

DOI:10.1139/m68-201

出版商:NRC Research Press    

年代:1968

数据来源: NRC

摘要:

Hydrogenomonas facilisATCC 15376 was shown to possess a photoreactivation system which was able to repair ultraviolet radiation damage under both heterotrophic and autotrophic conditions. Acriflavine enhanced the lethal effect of ultraviolet radiation onH.facilis.Five strains of ultraviolet-irradiated bacteriophage specific forH.faciliswere photoreactivated in infected bacteria. One strain, SH6, was markedly more resistant to ultraviolet inactivation.Visible light inhibited the synthesis of bacteriophage byH.facilisexcept for strain SH6. Incubation of SH6-infected bacteria in the light increased the titer more than 10-fold.

ISSN:0008-4166    

DOI:10.1139/m68-202

出版商:NRC Research Press    

年代:1968

数据来源: NRC

摘要:

The development of Sindbis virus in mouse embryo fibroblasts was found to vary according to the temperature of incubation. An augmentation in these temperatures was followed by a prolongation of the lag period and a decrease in the final yield. At 38 °C, 39 °C, and 40 °C the virus titer was respectively 50%, 16%, and 1.3% of that observed at 36 °C.Interferon production at 38 °C was equal to, or greater than, at 36 °C but at 39 °C and 40 °C it was respectively 1.4 and 5 times lower than that found at 36 °C.These results permit us to presume that the inhibition of Sindbis virus development at supra-optimal temperatures cannot be attributed to an increase of interferon production.

ISSN:0008-4166    

DOI:10.1139/m68-203

出版商:NRC Research Press    

年代:1968

数据来源: NRC

摘要:

The species ofErwiniaused in cell division studies (Grula 1960a) will grow onL- orD-aspartic acid, but no other amino acid, as a sole source of carbon, nitrogen, and energy. Ammonia is utilizable as a sole source of nitrogen; in this case the rate and extent of growth are significantly influenced by the carbon source. Of all compounds tested, malic acid supports the most rapid and abundant growth in an ammonium chloride – mineral salts medium. Added pantothenate often stimulates growth in ammonium chloride media, but not in aspartic acid media. Growth in an ammonium chloride – glucose – salts medium is rather slow and limited. Marked stimulation occurs by supplementation with intermediates of the Krebs cycle, even though the compound supports little or no growth as a sole carbon source. NeitherL-glutamic acid nor α-ketoglutaric acid supports growth as a sole carbon source; this is believed to result from impermeability of the cell to these compounds.

ISSN:0008-4166    

DOI:10.1139/m68-204

出版商:NRC Research Press    

年代:1968

数据来源: NRC

摘要:

D-Serine-induced inhibitions of growth and cell division ofErwiniasp. are greatly influenced by the pH and composition of the medium. In a glucose-aspartic medium, optimum elongation occurs at pH 6.8–7.2. In an aspartic acid medium, glucose, independently of pH, enhances division inhibition, but reduces growth inhibition. In ammonia media, a high toxicity is generally accompanied by poor inhibition of division. Division inhibition in ammonia media increases with decreasing ammonia concentration, and with increasing pantothenate concentration. Growth inhibition and division inhibition can, to a large extent, be varied independently of one another. Because of the nutritional dependence of division inhibition, it is proposed that the primary mechanism controlling the rate of division with respect to the rate of growth, and hence cell length, is at the metabolic level.D-Serine causes a marked accumulation of keto acids in most ammonia media as well as in a glucose – aspartic acid medium. This accumulation, decreased by added pantothenate, is the result of inhibition of pantothenate synthesis.D-Serine inhibits the entry of aspartic acid into the cell; this is a major factor inD-serine inhibition of growth. Filaments grown in the presence ofD-serine show no decrease relative to normal cells in content of DNA, RNA, or protein.

ISSN:0008-4166    

DOI:10.1139/m68-205

出版商:NRC Research Press    

年代:1968

数据来源: NRC