The Lipase of Pseudomonas fragi III. Enzyme Action in Cream and Butter

Nashif, S.A.; Nelson, F. E.

doi:10.3168/jds.s0022-0302(53)91524-0

Cited by 26 publications

(13 citation statements)

References 4 publications

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“…Zn 2 + , Fe 2 + and Fe 3 + strongly inhibited the enzyme activity. The effects of these metal ions on the activity of this enzyme are 'similar to that of the lipases from Chromobacterium viscosuml 8 ) and Ps. fluorescens.…”

Section: Discussionmentioning

confidence: 58%

Purification and Some Properties of Lipase Produced byPseudomonas fragi22.39 B

Nishio

Chikano

Kamimura

1987

Agricultural and Biological Chemistry

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Section: Discussionmentioning

confidence: 58%

Purification and Some Properties of Lipase Produced byPseudomonas fragi22.39 B

Nishio

Chikano

Kamimura

1987

Agricultural and Biological Chemistry

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“…The production of bacterial extracellular substances, including secondary metabolites from the fluorescent pseudomonads which exhibit antibiotic activity, has been a subject of extensive study (1,3,4,5,7,8,13,17,(19)(20)(21)26). The presence of such substances in a bacterial medium, however, does not necessarily indicate that they are produced physiologically rather than as a result of cell autolysis.…”

Section: Resultsmentioning

confidence: 99%

“…The samples assayed contained 1 mg of ATF protein per ml. DISCUSSION P. fluorescens is a saprophytic bacterium (27) occurring in soil and commonly found as a contaminant of water, milk, and other refrigerated dairy foods (16)(17)(18)23). It is psychrophilic and grows best at room temperature.…”

Section: Resultsmentioning

confidence: 99%

“…For example, lysis of Staphylococcus aureus was produced by both P. aeruginosa and P. fluorescens (28). A protease was characterized from strain 26 of P. fluorescens, and lipase activity was exhibited by both P. fluorescens and P. fragi (16)(17)(18)22). However, these substances appear to be different from those reported in this study, e.g., in regard to molecular weight and resistance to heat and freezing.…”

Section: Resultsmentioning

confidence: 99%

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Lysis of Trypanosoma cruzi by Pseudomonas fluorescens

Mercado

Colón-Whitt

1982

Antimicrob Agents Chemother

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Trypomastigotes of Trypanosoma cruzi isolated from the blood of infected mice were lysed within 24 h by an extracellular substance produced by Pseudomonas fluorescens. Isolation of the anti-trypanosomal factor (ATF) was accomplished by growth of the organisms in a defined medium, extracellular secretion by the sedimented cells, sterilization by filtration, lyophilization, dialysis, and gel filtration. Chromatographic separation with Sephadex G-25 and G-200 disclosed the occurrence of three active fractions. ATF-I(1) exhibited a molecular weight higher than 440,000. ATF-II and ATF-III were considerably smaller (molecular weights approximately 1,355 and 1,060, respectively). The lytic substance contained protein and lipopolysaccharide, was resistant to heat and freezing, was not proteolytic or hemolytic, and was not inhibited by trypsin but was suppressed by pronase.During studies of Trypanosoma cruzi, we observed that the number of trypomastigotes isolated from the blood of infected mice markedly diminished when maintained in vitro at 4°C for 3 days. Microscopic examination revealed that the parasite samples had become contaminated by a small, motile, rod-shaped microorganism that was attracted to the parasites, particularly to the posterior end. As a result of the interaction, the trypomastigotes became immobilized, and most were lysed within 24 h. A gram-negative bacterium isolated in blood agar and nutrient broth cultures was identified as Pseudomonas fluorescens by the Clinical Pathology Department, National Institutes of Health. We considered these observations to be significant not only in terms of cellular biology and physiology, but also because of their potential significance in the chemotherapy of Chagas' disease; further studies were therefore conducted to analyze the parasite-bacterium interaction.MATERIALS AND METHODS Parasites. The Tulahuen strain of T. cruzi is routinely maintained in this laboratory by blood passaging every 6 days in NIH-Swiss 16-to 20-g male mice; 4 x 106 to 5 x 106 trypomastigotes are usually inoculated intraperitoneally (14). The infection becomes acute after 6 days, producing marked pathology of liver and spleen, and blood counts of 108 parasites per ml are often obtained. The animals are not immunosuppressed. Blood samples are obtained under ether anesthesia directly from the heart after exposure of the cardiac surface. Parasites were isolated from blood by a two-step procedure (15) involving separation of the erythrocytes with Lymphoprep (9.6% sodium-Nmethyl-3,5-diacetamido-2,4,6-triiodobenzoate and 5.5% Ficoll; specific gravity, 1.077; Nyegaard and Co., Oslo, Norway) and elution through a DEAEcellulose column to remove lymphocytes and platelets. The eluted flagellates exhibited the usual lanceolate shape (6), were actively motile and elicited typical infections. Two myotropic strains of T. cruzi, the House 510 and the House 11, of Costa Rican and Nicaraguan origin, respectively, trypomastigotes of T. rhodesiense 1886, T. equiperdum, and promastigotes of Leishmania brasilien...

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“…A este respeito, Nashiff e Nelson 24 (1953) referem que as lipases produzidas por algumas espécies de Pseudomonas são ativadas a um pH entre 5,5 e 6,5 e inativadas a um pH 4,5.…”

Section: Introductionunclassified

Alguns grupos de microrganismos em manteigas vendidas no município de São Paulo

Iaria

1981

Rev. Saúde Pública

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Foram colhidas 105 amostras de manteiga de 5 marcas diferentes vendidas em supermercados da cidade de São Paulo (Brasil) com a finalidade de verificar as condições microbiológicas de manteigas e compará-las com os padrões recomendados. Semanalmente foi colhida uma amostra de cada marca, durante 21 semanas. A partir da parte aquosa de cada amostra, foram realizadas as contagens de bactérias mesófilas e psicrófilas (em ágar padrão e ágar gelisato), coliformes, proteolíticas e de bolores e leveduras e os resultados comparados com alguns parâmetros propostos por vários pesquisadores. Os valores obtidos nas contagens dos vários grupos de microrganismos estudados, em muitos casos podem ser considerados altos, os quais podem ser resultado do processamento e/ou conservação, realizados em condições não satisfatórias.

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The Lipase of Pseudomonas fragi III. Enzyme Action in Cream and Butter

Cited by 26 publications

References 4 publications

Purification and Some Properties of Lipase Produced byPseudomonas fragi22.39 B

Purification and Some Properties of Lipase Produced byPseudomonas fragi22.39 B

Lysis of Trypanosoma cruzi by Pseudomonas fluorescens

Alguns grupos de microrganismos em manteigas vendidas no município de São Paulo

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