摘要:

All of the intermediates of the citric acid cycle are shown to be present in the mycelium of 6-day cultures ofP.blakesleeanusgrown on glucose and on ammonium sulfate, and fed non-radioactive acetate on the fourth and fifth days and acetate-1-C14on the fifth day of incubation.The concentration of organic acids and certain amino acids, and their specific activity is reported. The high activity of the latter is thought to indicate the presence of a highly labeled pool of nitrogen compounds persisting from the early anabolic reactions after acetate-1-C14administration.

ISSN:0008-4166    

DOI:10.1139/m66-001

出版商:NRC Research Press    

年代:1966

数据来源: NRC

摘要:

Bentonite particles can be sensitized by both somatic O and H (flagellar) soluble antigens. After fixation, washing will remove the unadsorbed O antigen, and also partially elute the flagellar antigen.The serological response of rabbits to immunization with typhoid vaccines was compared by Widal bacterial agglutination and by bentonite flocculation. Bentonite had a limited ability to react with early type antibody, but matched the sensitivity of Widal aggultination for secondary response agglutinins. While bentonite particles are preferentially clumped by secondary response antisera, both mercaptoethanol resistant (7S) and mercaptoethanol-sensitive (19S) antibodies are responsible for bentonite flocculation.

ISSN:0008-4166    

DOI:10.1139/m66-002

出版商:NRC Research Press    

年代:1966

数据来源: NRC

摘要:

Lysozyme in combination with ethylenediamine tetraacetic acid (EDTA) gives rise to spheroplasts whenMycobacterium tuberculosisis cultured in a nutritionally complete Tween 80 – albumin medium. These spheroplasts do not multiply in this medium, but when such forms, stabilized by the presence of sucrose and Mg++, are inoculated into PPLO agar or broth an L-form of growth is initiated. A CO2requirement was demonstrated by L-forms grown on solid media.

ISSN:0008-4166    

DOI:10.1139/m66-003

出版商:NRC Research Press    

年代:1966

数据来源: NRC

摘要:

The potentiation of radiation damage by hadacidin in proliferatingE.colihas been investigated. Apparently this effect of hadacidin may be due to an effect in previously described mechanisms of inhibition by hadacidin: (a) inhibition of adenylosuccinate synthetase and (b) undefined inhibition of energy production.E.colicells grown in the presence of adenylic acid, adenine, oxalacetic acid, or anthranilic acid for 4 hours before exposure to radiation are insensitive to the hadacidin radiation effect.

ISSN:0008-4166    

DOI:10.1139/m66-004

出版商:NRC Research Press    

年代:1966

数据来源: NRC

摘要:

Experimental variables in the manometric study of iron oxidation by washed cell suspensions of the obligate chemoautotrophThiobacillus ferrooxidanshave been examined. To obtain maximum respiration rates, extremely low cell concentrations (11–15 μg nitrogen) must be used, the substrate level must be between 400 arid 800 μmoles Fe++in the form of ferrous sulfate, and physiologically young cells must be employed. With this procedure,Qo2(N) values range from 19,000 to 22,500, nearly double any previously reported results. Optimum pH and temperature for iron oxidation are 1.75 and 40 C, respectively. Water-soluble vitamins and surfactants have no effect on the rate of respiration, Two basal salts of the growth medium (9K), i.e., potassium chloride and potassium phosphate, inhibit iron oxidation if added individually; however, concurrent addition of all the basal salts stimulates respiration significantly. Addition of small amounts of ferric iron reduces the lag and stimulates iron oxidation, whereas larger quantities inhibit respiration. During the first 5 minutes of exposure of resting cells to ferrous sulfate, ferric iron production is twice the amount predicted on the basis of oxygen consumption. Subsequently, ferric iron production levels off to approximate theoretical calculations.

ISSN:0008-4166    

DOI:10.1139/m66-005

出版商:NRC Research Press    

年代:1966

数据来源: NRC

摘要:

An in vivo procedure is described for determining the relative sensitivities of potassium penicillin G and three semisynthetic penicillins to degradation byBacillus cereusandStaphylococcus aureuspenicillinases. The inactivating concentrations (IC50) of the penicillinases necessary to reduce the protective activity of each of the penicillins against anS.aureusinfection in mice from PD95to a PD50level was determined. Conventional in vitro studies were carried out for purposes of comparison. After interaction withB.cereuspenicillinase, Wy-3206 [6-(2-methoxy-1-naphthamido) penicillanic acid] had the greatest residual therapeutic activity, followed in order by nafcillin [6-(2-ethoxy-1-naphthamido)penicillanic acid], methicillin [sodium 6-(2, 6-dimethoxybenzamido)penicillinate monohydrate], and potassium penicillin G. Penicillin G proved to be the most sensitive to enzymatic degradation byS.aureuspenicillinase, whereas nafcillin and methicillin were resistant to the highest concentration employed. These findings were, in general, supported by the in vitro results.

ISSN:0008-4166    

DOI:10.1139/m66-006

出版商:NRC Research Press    

年代:1966

数据来源: NRC

摘要:

Previous studies have demonstrated that heating dry spores induced the formation of a high proportion of mutants. In this paper, a study was made of the correlation between the temperature of the heat treatment and the proportion of auxotrophic mutants induced. This proportion was found to increase between 105° and 115°, and then to decline (115°–155°). The proportions of auxotrophs forindividualamino acids reached maxima at various temperatures.

ISSN:0008-4166    

DOI:10.1139/m66-007

出版商:NRC Research Press    

年代:1966

数据来源: NRC

摘要:

Radiotracer studies confirm that the major products of glutamic acid metabolism byMicrococcus aerogenesare acetic acid, butyric acid, and carbon dioxide. When glutamic acid-1-C14was used as tracer the carboxyl carbons of both acetic and butyric acid were highly radioactive. Carbon 3 of butyric acid also contained some carbon-14. Glutamic acid-2-C14yielded acetic and butyric acid, both of which were highly labelled in carbon 2; carbon 4 of the butyric acid containing some carbon-14. All positions of acetic and butyric acid contained radioactivity when glutamic acid-3, 4-C14was used but carbons 3 and 4 of butyrate were much more highly labelled than carbons 1 and 2. Glutamic acid-5-C14was the only source of radioactive carbon dioxide.The data suggest that some of the butyric acid was derived from the intact four-carbon sequence which constitutes carbons 1, 2, 3, and 4 of glutamic acid and therefore, a pathway of glutamic acid degradation hitherto not recognized must occur inM.aerogenes.

ISSN:0008-4166    

DOI:10.1139/m66-008

出版商:NRC Research Press    

年代:1966

数据来源: NRC

摘要:

The production of pigmented cells ofMicrococcus violagabriellaegrown in shake cultures was studied. Pulcherriminic acid was isolated from the pigment and characterized. It was concluded that the insoluble red pigment obtained from the cells was pulcherrimin, identical with the pigment ofCandida pulcherrima.

ISSN:0008-4166    

DOI:10.1139/m66-009

出版商:NRC Research Press    

年代:1966

数据来源: NRC

摘要:

Various complex supplements including Bacto-casamino acids when added to a minimal salts glucose medium increased the bacterial count on suspensions of cells of bothAerobader aerogenesandEscherichia colifrozen and stored for 3 weeks. Replica plating procedures established that no auxotrophic mutants had been formed. Attempts to fractionate Casamino acids revealed that the active material could be retained by and eluted from both acidic and basic ion exchange resins. A mixture of 18 crystalline amino acids was equally as good as Casamino acids as a supplement to the minimal medium forA.aerogenes. Cystine was the most effective of the amino acids in the mixture tested singly, though other amino acids singly and in combination also increased the bacterial count. Cysteine was even more active than cystine and as effective as the Casamino acids for both organisms. Ethylenediaminetetraacetic acid had some activity forA.aerogenesbut little forE.coli. Cells frozen and stored were more sensitive to added phosphate in the medium than unfrozen cells. It is postulated that freezing and storage damage the cytoplasmic membrane of a proportion of the cells rendering them more penetrable by toxic metal ions present as trace contaminants. The enriched medium would permit growth of damaged cells by providing compounds capable of chelating the toxic ions.

ISSN:0008-4166    

DOI:10.1139/m66-010

出版商:NRC Research Press    

年代:1966

数据来源: NRC