摘要:

Clostridium perfringenstype C theta toxin was purified by ammonium sulfate precipitation, gel filtration, and ion-exchange chromatography. The purified toxin was free of alpha, beta, delta, and kappa toxins. Electrophoresis of the toxin in both the anionic polyacrylamide disc gel and in the polyacrylamide dodecyl sulfate gel yielded single protein bands.L-Lysine was determined as the sole N-terminal amino acid. The specific hemolytic activities of two purified preparations were 3.6 × 106and 4.8 × 106 HU/mg N; the specific toxicities were 8.1 × 103and 7.7 × 103mouse MLD/mg N. The molecular weight determined by the polyacrylamide – dodecyl sulfate method was 74 000.

ISSN:0008-4166    

DOI:10.1139/m73-141

出版商:NRC Research Press    

年代:1973

数据来源: NRC

摘要:

Electron microscopic examination of a semipurifiedChlamydia psittaci6BC strain attenuated in chick embryo yolk sac revealed for the first time two morphologically distinct small elementary bodies which differ both in the ultrastructure of their surface layers and in their buoyant densities in sucrose gradients. Also, the morphology of the surface layers of the larger reticulate forms in cell-free systems is described for the first time. Many points of difference between the surface envelopes and internal structure of chlamydial particles and those of Gram-negative bacteria are discussed.

ISSN:0008-4166    

DOI:10.1139/m73-142

出版商:NRC Research Press    

年代:1973

数据来源: NRC

摘要:

Cultural and colonial morphology of 120 strains of nocardiae had been determined in three different semisynthetic media. On the basis of ability or inability to grow in the most reduced medium, and of growth pattern observed in the other liquid media, the nocardiae were categorized in six cultural groups. The reproducible and clear-cut cultural properties are considered a useful criterion for species differentiation.

ISSN:0008-4166    

DOI:10.1139/m73-143

出版商:NRC Research Press    

年代:1973

数据来源: NRC

摘要:

The virulence ofNocardia brasiliensis,N.asteroides, andN.caviaewas investigated. The study was done by inoculation of these organisms into the footpad of white mice. The results show thatN.brasiliensishas greater virulence thanN.asteroidesandN.caviae. These observations resemble clinical findings in whichN.brasiliensisacts as an obligatory pathogenic agent, whereasN.asteroidesusually behaves as an opportunistic pathogen.Nocardia caviae, which is very similar toN.asteroidesfrom the taxonomic standpoint, is only rarely a causative agent for mycetoma.

ISSN:0008-4166    

DOI:10.1139/m73-144

出版商:NRC Research Press    

年代:1973

数据来源: NRC

摘要:

Numerous well-developed lomasomes appeared inRhizopus stolonifersporangiospores in response to anoxia. The lomasomes usually appeared between the plasmalemma and the inner cell wall, though some were found as deeply invaginated channels of the plasmalemma. Hence, lomasome configuration depended on the sectioning plane of the spore. They appeared either as a boundary structure or as an isolated inclusion within the cytoplasm. It is suggested that lomasomes inR.stolonifersporangiospores arise by elaboration of the plasmalemma, developing in association with the increasing thickness of the inner spore wall.

ISSN:0008-4166    

DOI:10.1139/m73-145

出版商:NRC Research Press    

年代:1973

数据来源: NRC

摘要:

The effect of temperature on growth rate, uptake of 2-deoxyglucose, and uptake and incorporation ofL-leucine is described for six Gram-positive, nonsporing bacteria. The organisms, designated as psychrotrophs because of their ability to grow at 10C, areListeria monocytogenes,Erysipelothrix rhusiopathiae,Microbacterium thermosphactum,Brevibacterium linens,Lactobacillus buchneri, andStreptococcus faecalis. The complexity of the results illustrates the difficulty of choosing simple criteria for comparing temperature responses of bacteria. However,L.monocytogenes,E.rhusiopathiae, andM.thermosphactumcan be grouped together on the basis of low temperature coefficients (less than 1.8) between 10 and 20C for 2-deoxyglucose uptake. This supports the conclusion that cold-resistant sugar-transport systems are among the fitness traits that permit bacteria to grow at low temperatures.

ISSN:0008-4166    

DOI:10.1139/m73-146

出版商:NRC Research Press    

年代:1973

数据来源: NRC

摘要:

Neurosporapyruvate kinase was protected by the substrates PEP and ADP and an allosteric effector FDP against inactivation by pronase. Alteration of proteolysis rates in the presence of these ligands is interpreted to be due to the existence of distinct conformational states. Protein fluorescence of native pyruvate kinase was quenched by the allosteric effector to an extent of about 50%. Fluorescence behavior of the enzyme in the presence of different ligands was consistent with the conclusions of proteolysis experiments.

ISSN:0008-4166    

DOI:10.1139/m73-147

出版商:NRC Research Press    

年代:1973

数据来源: NRC

摘要:

Water-soluble extracts of in vivo grown tubercle bacilli were found to have a lower carbohydrate content, a reduced number of antigenic components, and a weaker ability for detecting hemagglutinating antibodies in the sera of tuberculous patients than similar extracts prepared from the same strain but cultured in artificial medium.

ISSN:0008-4166    

DOI:10.1139/m73-148

出版商:NRC Research Press    

年代:1973

数据来源: NRC

摘要:

The utilization ofL(+)-tartrate inAspergillus flavusis constitutive. The use of tartrate by these cells is inhibited by the metabolic poisons 2,4-dinitrophenol and sodium azide. Glucose, mannose, and sucrose at high extracellular concentrations prevent the utilization ofL(+)-tartrate by the young mycelium. Ammonium ion increases the inhibition due to glucose, while the addition of ferric ions to the external medium prevents the glucose-induced inhibition of tartrate utilization.

ISSN:0008-4166    

DOI:10.1139/m73-149

出版商:NRC Research Press    

年代:1973

数据来源: NRC

摘要:

A cyclohexanecarboxylic acid utilizing bacterium, strain MU, has been isolated from soil and its taxonomic and physiological nature studied. The organism requires biotin or an unidentified factor present in yeast extract for growth, and can use one of various acids, alcohols, and carbohydrates as the sole carbon source.As the organism is a non-motile rod, gram-positive, non-sporing, not acid-fast, catalase-positive, and aerobic, it is identified as aCorynebacterium. Various growth and biochemical characteristics show that the organism is closely related toCorynebacterium equibut differs in several characteristics. Hence, a separate species,Corynebacterium cyclohexanicumis proposed for strain MU because of its unique use of cyclohexanecarboxylic acid. Results from manometric experiments indicate that its metabolism of cyclohexanecarboxylic acid is closely related to the well-established metabolic scheme of benzoic acid.

ISSN:0008-4166    

DOI:10.1139/m73-150

出版商:NRC Research Press    

年代:1973

数据来源: NRC