摘要:

AbstractSalmonella typhimuriumstrain 4a is a temperature‐sensitive division mutant. At 39° or 42° in several media a septation lesion occurs since non‐septate filaments form at these temperatures. At lower temperatures in some media separation is aberrant since long chains of cells are formed. Since these division abnormalities are corrected eitherbyrevertion tots+or phenotypically by growth with sucrose, it is likely that both are the result of one lesion and that the component (S) which is temperature‐sensitive in strain4ais involved in both septation and separation. At 42° S is irreversibly inactivated but at 39° inactivation appears to be reversible since division restarts rapidly when 39° filamentsarereturned to 25° and protein synthesis is not required for such division. Comparison of recovery times for 39° and 42° filaments suggests that the synthesis of enough S for division takes about 20 min at 25° while the septation and separation stages of division take only about 10 min at this temperature. Since these latter processes occur so quickly it seems likely that events other than septation and separation take up a substantial fraction

ISSN:0044-2208    

DOI:10.1002/jobm.19740140602

出版商:Akademie‐Verlag    

年代:1974

数据来源: WILEY

摘要:

AbstractAnenv Bmutant (strain D23) ofEscherichia coliK12 showing a distorted cell form was studied. The cells in a logarithmically growing D23 population are extremely heterogeneous with respect to size and shape. Different types of cells were studied in the electron microscope and the growth pattern was followed under the phase contrast microscope. The following observations were made: 1. All cells increase their mass by longitudinal growth. Inhibition of cell division results in filament or snake formation; the diameter of such cells is dependent on that of the original cell. 2. To a certain degree the size and shape of daughter cells is phenotypically determined by the parental cell. 3. Division of rod‐shaped cells of D23 is symmetric, whereas ovoid or coccoid cells show an asymmetric constriction. 4. After division of irregularly shaped cells, elongation of the daughter cells does not necessarily proceed perpendicular to the preceding division plane. The dependence of cell shape on growth direction and division pattern is emphasize

ISSN:0044-2208    

DOI:10.1002/jobm.19740140603

出版商:Akademie‐Verlag    

年代:1974

数据来源: WILEY

摘要:

AbstractEs wurde der Einfluß von Desoxyglucose, Jodacetat, Natriumfluorid, Malonsäure, EDTA, KCN, Natriumazid, α‐Dinitrophenol, Anaerobiose und Protaminsulfat auf das Phagocytosevermögen, die Beweglichkeit und den Stoffwechsel vonTetrahymena pyriformisuntersucht. Das Phagocytosevermögen für Tusche erwies sich als streng aerober, stoffwechselabhängiger Vorgang, ein Zusammenhang zwischen der Cilienbewegung und der Phagocytose ergab sich nicht. Trotz Steigerung der Sauerstoffaufnahme durch KCN, Na‐Azid und Dinitrophenol wirkten diese Substanzen auf das Phagocytosevermögen und die Beweglichkeit hemmend. Von den hier untersuchten Lebensäußerungen vonTetrahymenawar das Phagocytosevermögen gegenüber den Stoffwechselgiften am empfindlichsten, es war häufig schon bei sehr niedrigen Inhibitorkonzentrationen völlig erloschen, wenn die Atmung und die Beweglichkeit der Einzeller noch keinerlei Beeinträchtigung zeigten. Bei einem Vergleich mit anderen phagocytierenden Zellen, den polymorphkernigen Leukocyten der Säugetiere (PML), kommt vor allem der aerobe oxydative Stoffwechsel vonTetrahymenaim Gegensatz zum glykolytischen d

ISSN:0044-2208    

DOI:10.1002/jobm.19740140604

出版商:Akademie‐Verlag    

年代:1974

数据来源: WILEY

摘要:

AbstractThe unicellular algaeAnacystis nidulansandChlorella vulgariswere collected from effluents of the Indian Oil Refinery Barauni and the Sindri Fertilizer Factory (India), respectively, and isolated in unialgal and bacteria‐free culture.The algae were treated with the mutagen ethyl methane sulphonate and such mutagenically treated algae were compared with untreated controls with respect to growth characteristics and the capacity to absorb the two important components of polluted habitats, viz., phosphate and nitrate.TreatedA. nidulansgrew faster and showed a consistently higher uptake of phosphate than untreated. TreatedC. vulgariscells grew more slowly than untreated cells and showed lesser phosphate uptake during early phases of growth but greater uptake during the later phases.Nitrate uptake capacity was increased in both algae following treatmen

ISSN:0044-2208    

DOI:10.1002/jobm.19740140605

出版商:Akademie‐Verlag    

年代:1974

数据来源: WILEY

摘要:

AbstractMit Hilfe unterschiedlicher Hefeextraktkonzentrationen im Sporulationsmedium wurden inBacillus stearothermophilus‐Sporen unterschiedliche Dipicolinsäuregehalte synthetisiert. Nach Bestimmung des Calcium/Dipicolinsäure‐Molverhältnisses wurden die Hitzeresistenzdaten bei 121°C für endotroph beeinflußte Sporen ermittelt. Mit Erhöhung des Dipicolinsäuregehaltes und Herabsetzung des Calcium/Dipicolinsäure‐Molverhältnisses in den Sporen erhöhte sich di

ISSN:0044-2208    

DOI:10.1002/jobm.19740140606

出版商:Akademie‐Verlag    

年代:1974

数据来源: WILEY

摘要:

AbstractThe cytotoxic and antibiotic activity of the red‐pigment antibiotic violamycin of the anthracycline group was studiedin vitroin comparison with daunomycin, a known member of anthracycline antibiotics. Violamycin is a mixture of the complexes violamycin A and violamycin B. The cytotoxic minimal concentration of violamycin in primary cell strains (struma cells) amounts to 0.5 mcg/ml, but in permanent cell lines (HeLa‐, PN‐, Fl‐ell lines) from 0.5 to 1.0 mgc/ml. Daunomycin shows the same cytotoxic minimal concentration as violamycin, the antimitotic action of violamycin is lower than the action of daunomycin.In spite of the same minimal cytotoxic concentration of both drugs the mitotic index of HeLa‐ells treated with daunomycin (0.5 mcg/ml) for a period of 12 to 72 hours is less than 70 to 80% opposite that caused by violamycin (0.5 and 1 mcg/ml). In violamycin‐treated HeLa‐ells the mitotic index increases from 35 to 70% after the exposure of the drug at the concentration of 0.5 mcg/ml for a period of 36 to 72 hours without changing the medium. This effect cannot be shown with daunomycin‐treated cells.Nevertheless, violamycin can be regarded as a mitotic agent which considerably decreases the number of mitoses. The quantitative inhibition of cell division depends on the concentration, the time of exposure, the way of application, and the kind of the antibiotic. By all means, the inhibition of mitosis due to the effect of violamycin or daunomycin is pointed out to be reversible. If the drugs are removed and the cells brought back into plain medium a significant increase of the mitotic index can be observed after an incubation of 12 hours.At concentrations of 0.5 mcg/ml and more violamycin causes serious cytological changes and leads to irregular rearrangements of chromosomes, dark caps, and clumped chromatin. The results are discussed in comparison to the effec

ISSN:0044-2208    

DOI:10.1002/jobm.19740140607

出版商:Akademie‐Verlag    

年代:1974

数据来源: WILEY

摘要:

AbstractAs a prerequisite of the quantitative determination of cyclopenase activity during detach ment and ripening of the conidiospores ofPenicillium cyclopiumWESTLINGandP. viridicaturnWESTLINGa method for the disintegration of the spores without loss of cyclopenase activity was developed. From the procedures tested (X‐press, mixtures of acetone ‐ water at different temperatures, ultrasonic vibrations, grinding with sand, and repeated freezing and thawing) due to the spherical shape of the conidia and their thick cell wall only treatment with the X‐press and with acetone ‐ water (9:1) at +20°C, respectively, gave satisfactory results. In serial examinations the latter method is of advantage. However, before use its efficiency must be tested by comparison with X‐press disruption because spores of different strains show differences in their resistance to acetone and the physiological conditions during spore formation may influence t

ISSN:0044-2208    

DOI:10.1002/jobm.19740140608

出版商:Akademie‐Verlag    

年代:1974

数据来源: WILEY

ISSN:0044-2208    

DOI:10.1002/jobm.19740140609

出版商:Akademie‐Verlag    

年代:1974

数据来源: WILEY

ISSN:0044-2208    

DOI:10.1002/jobm.19740140610

出版商:Akademie‐Verlag    

年代:1974

数据来源: WILEY

ISSN:0044-2208    

DOI:10.1002/jobm.19740140611

出版商:Akademie‐Verlag    

年代:1974

数据来源: WILEY