bluuebunny/crossref_metadata_2025 huggingface dataset:
Study on the application range of the MP‐MM in vias analyzing
Authors: Li Hailiang , Tian Yu , Tong Ling
Published: July 2010

The feasibility of numerical calculations of a through‐hole via using the Matrix‐Penciled Moment Method (MP‐MM) proposed by Show‐Gwo Hsu and Ruey‐Beei Wu is investigated. It shows that the MP‐MM cannot be used to the via that is near the source port, and there is a lower bounded operating wavelength beyond which MP‐MM is not applicable. The conclusions in this paper are proven by both theory and the simulation results obtained by Ansoft's HFSS. Copyright © 2010 John Wiley & Sons, Ltd.
Circuit modeling for ultra‐wideband Tx‐Rx antenna systems based on frequency domainS‐parameters
Authors: Wang Y. , Li B. , Wu Z. M.
Published: July 2010

This paper presents a circuit modeling procedure for Ultra‐wideband (UWB) Tx‐Rx antenna systems based on frequency domainS‐parameters. The modeling used an existing two‐port network's model consisting of four SPICE analog behavioral modules. The accuracy of the model has been validated by comparing its transient response with the measurement result using an oscillograph. This model can be used for the co‐design of the UWB Tx‐Rx antenna system with transmitters and receivers in circuit simulators. In the study, Tx‐Rx antenna systems using planar bow‐tie antenna and horn antenna with ultra‐wide bandwidths are used as examples. Copyright © 2010 John Wiley & Sons, Ltd.
Cognitive processes in procedural justice judgments: The role of ease‐of‐retrieval, uncertainty, and experience
Authors: Janssen Jana , Müller Patrick A. , Greifeneder Rainer
Published: July 2010

In a field experiment with 517 job applicants, the processes underlying the formation of procedural justice judgments were investigated. It was hypothesized that procedural justice judgments may be based not only on content information (e.g., “What are fair aspects of the selection procedure?”), but also on the felt ease or difficulty with which this content information can be retrieved from memory (ease‐of‐retrieval; e.g., “How easily can I recall fair aspects of the selection procedure?”). Evaluations of the company's online application procedure show that job candidates based procedural justice judgments on content information or on ease‐of‐retrieval, depending on their uncertainty regarding the online application procedure as well as their prior experiences with online applications. Specifically, experienced applicants who felt certain based their judgments on ease‐of‐retrieval, whereas all other applicants based their judgments on content information. Implications for research on the formation of justice judgments as well as practical applications are discussed. Copyright © 2010 John Wiley & Sons, Ltd.
Antecedents and outcomes of contingent workers' attitudes toward their temporary help services firm: A unit level longitudinal investigation
Authors: Subramony Mahesh
Published: July 2010

This study explored the unit‐level antecedents and outcomes of contingent workers' attitudes toward their temporary help services (THS) firm. It was proposed that (a) client‐orientation levels of the THS firm's full‐time staff would influence the level of support received by contingent workers, (b) staff supportiveness would be reciprocated by these workers in the form of favorable firm‐directed attitudes, and (c) contingent workers' attitudes toward the THS firm would influence two unit‐level outcomes—client reported service failure, and voluntary turnover rates of THS staff. Support was found for all the hypothesized relationships in a longitudinal study utilizing survey data gathered from 1324 full‐time employees, 570 contingent workers, and 1951 clients; and archival data on staff turnover from 46 strategic business units (SBUs) of a THS firm. These results are discussed within the context of employee–organization relationship (EOR), contingent workforce, and service management literatures. Copyright © 2010 John Wiley & Sons, Ltd.
Sporulationsverhalten von Bacillus megaterium während Kohlenstoffhunger
Authors: Kretschmer Sigrid
Published: July 2010

Some parameters of sporulation were determined from different carbohydrate‐limited B. megaterium cultures, which grew with doubling times of τ = 45, 80, and 190 min, respectively. The frequency of spore formation was 90–95%.

Forespores and spores appeared asynchroneously. This asynchrony was due to the heterogenity in cell size of the populations. Spores within the smallest cells developed 90 min later than in the larger ones. As the extent of synchrony was the same with all three media, initiation of sporogenesis should occur independently of the respective stage of the cell cycle.

The time passing between t0 (begin of the stationary growth phase) and the formation of the spore septum varied in the different media. Thus, the time at which the latter process starts is not directly determined by the end of the net growth but probably by processes which are connected with initiation of cell division.

A model of cell division is presented according to that membrane synthesis during elongation of cells occurs at an annular zone at the newly formed poles of daughter cells. Sporulation septum then might be the product of a reinitiated, additional membrane synthesis at this site, the activity of which normally is repressed by the next division and remains repressed under non‐starvation conditions.
L‐Formen von Escherichia coli K 12 (λ) II. Elektronenoptische Untersuchungen
Authors: Gumpert J. , Schuhmann Edith , Taubeneck U.
Published: July 2010

Ultradünnschnitte der Zellen von E. coli K 12 (λ), einer mutierten instabilen L‐Form LK12(λ) inst I und einer aus dieser L‐Form revertierten Stäbchenform K12(λ) rev I wurden vergleichend elektronenmikroskopisch untersucht. Bei den normalen Zellen wurden drei und fünfschichtige Zellwände von 85–110 Ä bzw. 110–140 Ä, bei den revertierten Zellen stets nur eine dreischichtige Zellwand von 85–90 Ä Dicke gefunden. Bei vielen L‐Form Zellen war die beobachtete dreischichtige Zellwand (Dicke: 80–100 Ä) über mehr oder weniger große Bereiche unterbrochen oder nur noch in Form von Zellwandinseln vorhanden. Einige L‐Form‐Zellen wiesen außerdem unterschiedlich große Bereiche mit einer unterbrochenen cytoplasmatischen Membran auf. Das Nucleoid war in den normalen Zellen und den Zellen des revertierten Stammes deutlich vom ribosomenreichen Cytoplasma abgegrenzt, während es bei der instabilen L‐Form über die ganze Zelle verteilt erschien. Die pleomorphen Zellen der instabilen L‐Form waren im Gegensatz zu den Stäbchenzellen des Ausgangsstammes und des revertierten Stammes von einer mucoiden, im Durchschnitt 0,15 μm dicken Schicht kapselartig umgeben. Weitere ultrastrukturelle Besonderheiten werden im Zusammenhang mit der Vermehrungsweise der L‐Form diskutiert.
Factors influencing the production of kanamycin by Streptomyces canus
Authors: Abou‐Zeid A. A. , Salem H. M. , Essa A. I.
Published: July 2010

The production of kanamycin by three species of Streptomyces and four fermentation media was studied. Streptomyces canus in medium No. 2 gave the highest yields of kanamycin after 72 hrs. of fermentation. The presence of both molasses and glucose in the fermentation medium was an important factor for the production of kanamycin. The best concentration of molasses and glucose were 15.0 and 10.0 g/1, respectively. Replacement of peptone by equal amounts of inorganic and organic nitrogen sources was not suitable for the production of kanamycin, and peptone in a concentration of 5.0 g/1 gave the best results.
Relations entre l'état physiologique et l'aptitude à la sporulation chez la levure
Authors: Vezinhet Françoise , Galzy A. Arnaud Et P.
Published: July 2010

Cells harvested during logarithmic growth give a higher percentage of asci than cells harvested during stationary phase.

This observation is valide whatever the carbon source. When the culture is done on yeast extract 0.5%, glucose 0.5%, the cells during logarithmic growth have a weak acetate QO2, a high endogenous QO2. The activities of fumarase and isocitritase are also weak. All these characteristics are not incompatible with an abundant sporulation.
Das Fettsäurespektrum eines Candida‐Stammes nach Kultur auf n‐Alkanen
Authors: Hornei Sigrid , Köhler M. , Weide H.
Published: July 2010

In Kulturen des Candida‐Stammes H17 wurden n‐Alkane definierter Kettenlänge, das n‐Alkangemisch Mepasin II und zur Kontrolle Glucose als C‐Quelle angeboten.

Das jeweilige Spektrum der intrazellulären Fettsäuren veränderte sich in Abhängigkeit von der verwendeten C‐Quelle in charakteristischer Weise.

Ein Vergleich der extrahierten Carbonsäuren nach Wachstum auf den verschiedenen Alkanen sowie dem Alkangemisch Mepasin II ließ den stammspezifisch bevorzugten Abbau von Hexa‐, Hepta‐, Penta‐ und Oktadekan innerhalb des Kohlenwasserstoffgemisches erkennen.

Unterschiedliche Wachstumszeiten bei sonst unveränderten Versuchsbedingungen hatten keine qualitative Veränderung des Fettsäureprofils zur Folge. Die Gesamtmenge der extrahierten intrazellulären Fettsäuren erhöhte sich mit zunehmender Kulturdauer von 2 auf 4%.
Insensitivity to caffeine of phage‐controlled repair‐processes
Authors: Witte W.
Published: July 2010

It is shown by comparison of UV‐survival curves that repair‐functions controlled by phages T4 D (Escherichia coli) and VIr (Proteus mirabilis) are insensitive to caffeine. In connection with these experiments, a UV‐sensitive is‐mutant of phage VIr is described.
Produktion von Xylanase durch Bacillus subtilis
Authors: Lyr H.
Published: July 2010

Bacillus subtilis forms a xylanase complex which does not depend on induction by xylane or xylose in the medium.

The enzyme production is influenced by the kind of the carbon source, probably due to catabolic repression. The regulation of enzyme formation is complex in nature, because the C/N/P‐Relation in the medium, cell mass, and growth phase influence the amount of enzyme in the culture fluid. Maximal enzyme production was achieved at high but balanced amounts of C/N/P, although growth was strongly reprimed under these conditions. A formation of cellulase, aryl‐β‐xylosidase and aryl‐β‐glucosidase could not be observed.
Nikotinsäurebiosynthese bei Rhodotorula glutinis
Authors: Birnbaum D. , Böttcher F. , Samsonova I. A.
Published: July 2010

Die Nikotinsäurebiosynthese bei Rhodotorula glutinis verläuft nach dem „Neurospora”︁‐Weg, d. h., vom Tryptophan über verschiedene Zwischenstufen zur 3‐Hydroxyanthranilsäure und von dieser über die Bildung des Pyridinringes zur Nikotinsäure.

Das konnte mit Hilfe auxotropher Mutanten (Nic−‐Mutanten), bei denen unterschiedliche Schritte dieser Biosynthese durch UV‐Mutagenese blockiert worden waren, gezeigt werden.

Ob Chinolinsäure ein echtes Zwischenprodukt dieser Synthese ist, konnte auf Grund der Befunde nicht entschieden werden.
Untersuchungen zur Antigenstruktur von Shigellen VI. Bindung des N‐Acetylglucosamins in den O‐spezifischen Seitenketten der Lipopolysaccharide von Shigella flexneri Ib und Variante Y
Authors: Seltmann G. , Beer W.
Published: July 2010

Zur Bestimmung der Bindungsverhältnisse des in den O‐spezifischen Seitenketten der Lipopolysaccharide (LPS) von Sh. flexneri 2 (Serotyp 1b) und 1290/63 (Var. Y) enthaltenen N‐Acetylglucosamins wurden die O‐spezifischen Polysaccharide permethyliert. Nach Totalhydrolyse wurden die methylierten Glucosamine abgetrennt und entweder direkt oder in Form ihrer Alditolacetate mit Hilfe der Gaschromatographie, der Massenspektrometrie und der Perjodatoxidation charakterisiert. In den O‐spezifischen Seitenketten der LPS von Stamm 1290/63 liegt das Glucosamin als 1,6‐gebundenes N‐Acetylglucosamin vor, in denen von Stamm 2 konnten wir 1,6‐ und 1,3,6‐gebundenes (die Bindung 1,4,6 konnte nicht völlig ausgeschlossen werden) N‐Acetylglucosamin nachweisen. Dies ist ein Beweis dafür, daß nicht alle Glucosamine Träger zusätzlich gebundener Glucose (Kettenverzweigung) sind. Die Gründe hierfür werden diskutiert.
Vergleichende Untersuchungen über Phospholipid‐, DNS‐ und Proteingehalt von Escherichia coli W 1655 F+ und einer stabilen L‐Form
Authors: Geuther R. , Moltschanov M.
Published: July 2010

Die Zellbegrenzungen von Normal‐ und L‐Form von E. coli W 1655 F+ weisen im Phospholipidgehalt bezogen auf das Membranprotein und in den Bandenmustern nach Auftrennung der Membranproteine durch Polyacrylamidgelelektrophorese weitgehende Übereinstimmungen auf. Im Durchschnitt liegt der DNS/PLP‐ und der DNS/Proteinquotient in der L‐Form um 40% bzw. 100% über dem Wert der Normalform. In der Normalform sind in Abhängigkeit von der Wachstumsphase der Kultur 33–50% und in der L‐Form 45–75% des Gesamtphospholipids Phosphatidyläthanolamin. Die Quotienten DNS/Phosphatidyläthanolamin sind konstant und für L‐ und Normalform übereinstimmend in allen Phasen der Kultur. Durch Zentrifugation im Saccharosegradienten konnte aus L‐Form‐Kulturen eine DNS‐freie Minizellfraktion mit hohem Phospholipid/Proteinquotienten abgetrennt werden.
Computersimulation von Wachstum und Produktbildung bei Saccharomyces cerevisiae
Authors: Bergter F. , Knorre W. A.
Published: July 2010

A mathematical model with three modifications was stated, which describes the diauxic growth of Saccharomyces cerevisiae on aerobic conditions in a glucose‐limited medium. The model was investigated by means of an analogcomputer. The first and simplest modification of the model is based on a well‐known growth model and includes an additional team for catabolic respression. This 1st model could be fitted without complications to the experimental data of a batch culture, which shows growth, consumption of glucose, and production of ethanol during a first log‐phase and growth and consumption of ethanol during a second log‐phase. Complementation with the terms necessary for continuous culture conditions gives the 2nd model and, therefore, the possibility to predict the properties of the corresponding continuous culture. The prediction agrees qualitatively with the experimental data. After consideration of additional factors as the inhibition of growth and ethanol production by ethanol a 3rd model allowed to fit the experimental data of a continuous culture.
Untersuchungen zur Erdölmikrobiologie VI. Migration und Denitrifikation
Authors: Gode P. , Schwartz W.
Published: July 2010

The migration of oil in sediments and the accumulation in oil traps is still a problem not yet solved. After BAKER, KENNEDY and others, hydrocarbons may be solubilized by natural surfactants, i.e. salts (soaps) of fatty acids or naphthenic acids, and migrate in an emulsified stage or in micellar distribution. Accumulation in a trap is inaugurated by separation of the components. In a model experiment with columns filled with sand, we succeeded herewith in a system of paraffine oil, solubilized by sodium palmitate, and an enrichment of denitrifying bacteria adapted to palmitinic acid as a carbon source. Gas production in the sand was visible already the second day. Almost 99% of the hydrocarbons were entrapped in the sand after 30 days by the activity of the denitrifiers while in the control experiment, about 50% migrated through the column and the rest was filtered off nearly unchanged by the sand.
Degradation of progesterone by aspergilli‐side chain cleaving enzymes
Authors: El‐Refai A. H. , Abdel‐Fattah A. F. , Ibrahim K. A. , Sallam L. A. R.
Published: July 2010

The transformation properties of different aspergilli were tested. Our strains possess the capacity of degrading of progesterone side chain. Δ4‐androstene‐3,17‐dione, testosterone, and testololactone were detected in all cases but produced in different yields. Two strains, namely, Aspergillus niger 214 and A. flavus 181 proved to be the most active transformers. The transformation abilities of these two strains are profoundly affected by composition of the fermentation medium employed. The media containing ill‐defined compounds, e.g. peptone or yeast extract favour the production of enzymes catalyzing the degradation of the progesterone side chain. Various enzymic transformations of progesterone with these two strains were studied by allowing the fermentation to proceed at different time intervals. It was possible to illustrate schemes for such transformation reactions.
Einfluß von Pyridoxinmangel auf die Tryptophansynthase bei Neurospora sitophila
Authors: Aurich H. , Schöpp G.
Published: July 2010

Die Aktivität der Tryptophansynthase in zellfreien Mycelextrakten von Neurospora sitophila 299 ist vom Pyridoxolangebot im Kulturmedium abhängig. Im Pyridoxolmangel ist sowohl die Apoenzymkonzentration als auch die zur Verfügung stehende Menge an Pyrid‐oxalphosphat erniedrigt. Auch bei ausreichendem Pyridoxolangebot im Kulturmedium und maximaler Apoenzymkonzentration in den Hyphen ist die Aktivität der Tryptophansyn‐thase in vitro durch Pyridoxalphosphat noch um mehr als das Dreifache zu steigern. Der KM‐Wert für Pyridoxalphosphat wurde mit 0,8. 10−6 (M) ermittelt.

Auch die Konzentration an freiem Tryptophan im Pool der Mycelien ist vom Pyridoxol‐angebot im Kulturmedium abhängig, sie ist im starken Pyridoxolmangel erniedrigt und durchläuft mit steigenden Pyridoxolmengen ein Maximum.
Isocitratlyase von Candida guilliermondii, Stamm H 17 I. Reinigung und Charakterisierung
Authors: Weide H. , Hildebrandt W.
Published: July 2010

Die spezifische Aktivität der aus Candida guilliermondii, Stamm H 17, nach Anzucht auf Acetat als C‐Quelle gewonnenen Isocitratlyase konnte durch Ammoniumsulfatfällung (60–75%) und Gelchromatographie (Sephadex G 200) 3,7 fach angereichert werden.

Die gereinigten Enzymfraktionen wurden in der Polyacrylamidgelelektrophorese in 6–8 Banden aufgetrennt. Das nach Gelchromatographie geschätzte Molekulargewicht des Enzyms liegt zwischen 250000 und 270000.

Der optimale pH‐Bereich für die Enzymreaktion in Phosphatpuffer erstreckte sich von pH 6,5–7,2 mit dem Maximum bei 6,8. Das Enzym unterlag einer ausgeprägten Substrat‐hemmung mit einem KI‐Wert von 60 mM. Die Michaelis‐Konstante betrug 0,3 mM threo‐Ds‐Isocitrat. Die Isocitratlyase besitzt ein aktives Zentrum pro Enzymmolekül (Hill‐Koeffizient: n = 1).
Isocitratlyase von Candida guilliermondii, Stamm H17. III. Regelung durch Intermediate des Alkanabbaus und allgemeines Regulationsmodell
Authors: Hildebrandt W. , Weide H.
Published: July 2010

Die Aktivität der Isocitratlyase wurde durch Capronsäure (KI = 4,1 mM) stark gehemmt. Die anderen Monocarbonsäuren mit geradzahligen C‐Kettenlängen von 12 bis 2 sowie Adipinsäure und Hexanol beeinflußten das Enzym nur schwach oder bewirkten keine Inhibition.

Unter Berücksichtigung aller für diese Hefe ermittelten Hemmwerte und ‐typen wurde ein Modell der Regelung der Isocitratlyase entwickelt.
Alanin‐Dehydrogenaseaktivität und Antibioticumbildung in Kulturen des Streptomyces hygroscopicus JA 6599
Authors: Gräfe U. , Bocker H. , Reinhardt G. , Tkocz H. , Thrum H.
Published: July 2010

In order to estimate the role of alanine dehydrogenase (EC 1.4.1.1) in the precursor supplying system of antibiotic A 6599 biosynthesis by S. hygroscopicus JA 6599 the activities of this enzyme were studied in mycelial extracts.

Within the production phase of antibiotic A 6599 only slight differences in the enzyme activities of two strains producing different amounts of antibiotic were found. After the 2nd day of fermentation in complex medium cultures, however, a striking increase in alanine dehydrogenase activity was observed suggesting that variations of metabolism took place. This might be responsible in part for decay in antibiotic production due to deficiency of pyruvate as an intermediate of precursor formation. Evidence is given for enzyme induction by an excess of alanine or ammonia in the medium.

The addition of the antibiotic A 6599 to producing cultures causes a suppression of mycelial growth and ammonia metabolization as well as repression of the phosphoenolpyruvate carboxylase (EC 4.1.1.31) but it doesn't prevent completely regulating de novo synthesis of enzymes as alanine dehydrogenase.

The results point to the interference of the antibiotic A 6599 in the producing strains of this organism both with the metabolic regulation and precursor supply.
Quantitative Bestimmung des Enzyms Cyclopenase in Konidiosporen von Penicillium cyclopiumWESTLING und P. viridicatumWESTLING
Authors: Wilson S. , Schmidt I. , Roos W. , Fürst W. , Luckner M.
Published: July 2010

As a prerequisite of the quantitative determination of cyclopenase activity during detach ment and ripening of the conidiospores of Penicillium cyclopium WESTLING and P. viridica turn WESTLING a 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 the results.
Recombination deficient mutants of Streptococcus pyogenes K56
Authors: Malke H.
Published: July 2010

Nitrosoguanidine mutagenesis of the Group A streptococcal strain K56 known as a good recipient in phage‐mediated transduction led to the isolation of two recombination deficient mutants showing transduction frequencies of chromosomal markers about 100‐fold lower than those of the parent strain. These mutants were sensitive to ultraviolet (UV) irradiation but had retained their ability to reactivate UV‐irradiated phage A25. They were cross‐sensitive to the killing action of nitrosoguanidine and ethyl methane sulfonate and showed severely inhibited DNA synthesis after UV radiation.
Wirkung von einigen Pflanzenwachstumsregulatoren auf verschiedene Prokaryonten und deren Viren
Authors: Menzel G. , Stenz E. , Touré I. M. , Gebler B. , Schuster G.
Published: July 2010

26 plant growth regulators including herbicides were investigated in their effect on the multiplication of Escherichia coli, Bacillus subtilis, and the blue‐green alga Plectonema boryanum as well as the RNA phages M 12 and Qβ and the DNA phages λ, Ø 105, and LPP‐1 employing the agar diffusion method. Nearly all of the compounds inhibited and/or stimulated one or some of the prokaryotes tested. The most frequent and strongest effects occurred in Pl. boryanum, the least effects in E. coli. The multiplication of phages was also influenced by plant growth regulators leading to increase, decrease or non‐appearance of plaques. The investigations with the temperate phages λ and Ø 105 suggested part of the compounds to be able to interfere with the process of lysogenization. The results are discussed comparatively involving correspondent findings referred to in literature.
Wirksamkeit von Mureinpräparationen im Phagenhemmtest — Kinetische Untersuchungen
Authors: Beige U. , Seltmann G.
Published: July 2010

Kinetische Untersuchungen haben gezeigt, daß der Phage 187 irreversibel, der Phage 54 über‐wiegend irreversibel und der Phage 83A reversibel an ausgewählte Mureinpräparationen spezifisch gebunden wird. Es liegen Rezeptormechanismen vor.
Reduction of cycloalkanones by Aspergillus niger
Authors: Lemière G. L. , Alderweireldt F. C.
Published: July 2010

The mould Aspergillus niger was grown in a carefully established culture medium containing one of the following test substrates: cyclopentanone, ‐hexanone, ‐heptanone, and their 2‐substituted methyl derivatives. Growth curves, glucose consumption curves and curves showing the course of the oxido‐reduction reaction are given.
Repression der Ureasebiosynthese in Neurospora crassa durch Ammoniumionen
Authors: Schluttig A. , Fritsche W.
Published: July 2010

The regulation of the synthesis of the enzyme urease (urea amido hydrolase E.C. 3.5.1.5.) in Neurospora crassa was investigated. The biosynthesis of urease is repressed by ammonium ions. Under ammonium excess conditions the specific activity of urease decreases from 0.980 to 0.180 μmoles NH3/min/mg protein.

By addition of cycloheximide it was shown that ammonia influences the synthesis of this enzyme. Enzyme induction by the substrate could be excluded.

Even under the conditions of highest repression a specific activity of urease of 0.180 μmoles NH3/min/mg protein was measured. Possible causes of this constitutive enzyme level are discussed.
Wirkung von Terrazol auf die Ultrastruktur von Mucor mucedo
Authors: Casperson G. , Lyr H.
Published: July 2010

Terrazol, a systemic fungicide showing high specifity to oomycetes, inhibits the apical growth of hyphae and promotes at lower concentrations the thickening of the cell wall in Mucor mucedo. As revealed by ultrastructural analysis, particularly the fine structure of some membrane systems is influenced. In the first place the inner membrane of the mitochondria is attacked leading to a complete lysis of mitochondria. However, the sensitivities within a given population are different. The plasmalemma enlarges, forms several invaginations, partly redraws from the cell wall, but remains intact. Only after an extensive treatment with relatively high concentrations of terrazol the nuclear envelope shows vesicles between the double membranes. The mechanism of action of terrazol is discussed.
Bestimmung des Proteingehaltes von Streptomyceten mit Bromphenolblau
Authors: Hilliger M. , Lindner R.
Published: July 2010

Es wurde die Anwendung der von HESSE et al. (1971) beschriebenen Proteinbestimmungsmethode mit Bromphenolblau auf Streptomyceten untersucht. In Ergänzung dieser Methode macht sich bei Verwendung von Streptomyceten ein Ultraschallaufschluß notwendig. Der relative Fehler σ der Mittelwerte von fünf unabhängigen Proteinbestimmungen von ultraschallhomogenisierten Mycelsuspensionen zu je 10 Parallelwerten schwankt zwischen 0,9% und 1,4% und beträgt im Mittel 1,2%. Die Untersuchung der Methodik der Homogenisierung des Mycels mittels Ultraschall ergab unter den gegebenen apparativen Bedingungen eine Mindestbeschallzeit von einer Minute. Die Extinktion des eluierten Farbstoffs ist nahezu linear abhängig von der auf die Filterblättchen aufgebrachten Menge an Protein einer mittels Ultraschall homogenisierten Streptomycetensuspension. Streptomyces hygroscopicus‐Protein und Serumalbumin unterscheiden sich hinsichtlich ihrer Farbstoffbindung kaum, so daß Serumalbumin als Bezugsprotein verwendet werden kann. Es ist sehr wahrscheinlich, daß keine Abhängigkeit zwischen Anfärbbarkeit des Proteins von S. hygroscopicus und der Wachstumsphase bei diskontinuierlicher Kultivierung existiert.
Zur Deutung des an biologischen Objekten gemessenen Redoxpotentials. VII. Messungen in Elektrolytlösungen mit verschiedenen Platinelektroden
Authors: Jacob H.‐E. , Stur Judith K. , Marek N.
Published: July 2010

Durch die Verwendung von Membranmeßketten und blanken Platinelektroden zur Messung des Redoxpotentials (ROP) wurde es möglich, den Einfluß, den gasförmige Komponenten und ionisch gelöste Redoxsubstanzen auf das ROP von blanken Pt‐Elektroden haben, voneinander zu trennen.

Mit dem Redoxsystem Kalium‐hexacyanoferrat (III und II) konnten durch Veränderung der Konzentration drei Bereiche erkannt werden, die sich durch die Wirkung des pO2 auf das ROP unterscheiden.

Im ersten Bereich bestimmt die Substanz das ROP, und außerdem spielt der Zustand der Elektrodenoberfläche keine entscheidende Rolle. — Im Übergangsbereich machen sich bereits pO2‐Änderungen im ROP bemerkbar. — Im dritten Bereich bestimmt der pO2 das ROP der Lösung. Der Zustand der Elektrodenoberfläche ist entscheidend für den gemessenen ROP‐Wert.

Diese grundsätzlichen Ergebnisse wurden auch mit dem Redoxsystem H2O2/KMnO4 festgestellt.

Dem dritten Bereich sind in der Regel die an biologischen Objekten gemessenen ROP‐Werte zuzuordnen.
Iron bacteria of the genus Siderocapsa in mineral waters
Authors: Švorcová Libuse
Published: July 2010

The occurrence of iron bacteria in mineral waters has been under study. It could be shown that Siderocapsa coronata REDINGER 1931 and S. treubii MOLISCH 1909 are synonymous, as well as S. eusphaera SKUJA 1948 and S. major MOLISCH 1909, and S. botryoides BEGER 1949 and S. monoica 1922. Two new species, S. hexagonata and S. quadrata, have been described. A simplified key for determining the species of the genus Siderocapsa is presented.
Wirkung von Polyen‐Makrolidantibiotica auf normale und zellwandlose Zellen vonEscherichia coliW1655F+
Authors: Haupt Ina , Schuhmann Edith , Geuther R. , Thrum H.
Published: July 2010

The polyene macrolide antibiotics are active against yeasts, fungi, and other eukaryotic cells, but are with a few exceptions inactive against bacteria. The resistance of bacteria against these compounds is usually explained by the absence of sterols in their cells, the target sites of polyene antibiotics.

However, in our experiments with mycotrienin, nystatin, tetramycin, lucensomycin, rimocidin, filipin, lagosin, flavofungin, flavomycoin, antibiotic 2814 P, antibiotic 5001 P, and candicidin it was demonstrated that bacteria may be susceptible to polyene antibiotics, too, if the wall‐less stable protoplast type L‐form ofE. coliW1655F+is used. The measured growth inhibition concentrations were comparable with those of typical antibacterial antibiotics.

Our experiments have shown that the normal rod form and the wall‐less L‐form ofE. coliW1655F+contain traces of sterols in nearly the same concentration range. This means that the selective sensitivity of the L‐form cannot be explained by higher sterol content of these cells in comparison to the resistant normal rod form cells. We assume that the bacterial cell wall is responsible for the resistance of the normal rod form by masking internal target sites.
Einfluß definierter Substrat‐Limitationen auf das Enzym‐und Metabolitmuster des methylotrophen BakteriumsPseudomonasW 6
Authors: Hofmann K. , Sawistowsky J. , Babel W.
Published: July 2010

Der Zusammenhang zwischen Milieubedingungen und der Konzentration zentraler Stoffwechselintermediate sowie der Konzentration bzw. der Aktivität von Enzymen des Citratzyklus und der Synthese von Glutamat wurden bei dem obligat methylotrophen BakteriumPseudomonasW 6 untersucht.

Die Konzentrationen der Glutamatdehydrogenase, der Isocitratdehydrogenase, der Glutamat‐Oxalacetat‐Transaminase und NADH‐Oxidase ändern sich in der stationären Wachstumsphase gegenüber der exponentiellen praktisch nicht und sind unabhängig von der Art der Limitation (NH4+, Methanol, O2). Dagegen steigt die Aktivität der Glutaminsynthetase erwartungsgemäß an, wenn die stationäre Phase durch NH4+‐Mangel eingeleitet wird.

Glycerinaldehyd‐3‐phosphat, Dihydroxyacetonphosphat und Isocitrat konnten unabhängig von den Mangelbedingungen in keinem Fall mit Hilfe enzymatischer Bestimmungsmethoden nachgewiesen werden. Die zellulären Konzentrationen an Pyruvat und α‐Ketoglutarat steigen unter NH4+‐Mangelbedingungen um das 2‐ bzw. 70 fache an, unter Methanol‐Mangelbedingungen ändern sich die Konzentrationen gegenüber der exponentiellen Phase nicht. Das Anstauen von α‐Ketoglutarat wird als ein weiterer Beweis für den offenen Citratzyklus beiPseudomonasW 6 diskutiert. Die hohe Pyruvatkonzentration und die geringe Aktivität des Pyruvat‐Dehydrogenase‐Komplexes deuten darauf hin, daß dieses Enzym für den Citratzyklus “key enzyme” — Funktion besitzt.
Physiologischer Zustand von Bacillus megaterium im Chemostaten unter alkalischen Bedingungen
Authors: Ivanova I. I. , Shaforostova L. D. , Sakharova Z. V. , Hilliger M.
Published: July 2010

Es wurde der Einfluß alkalischer Kultivierungsbedingungen (pH > 7,0) auf Bacillus megaterium im Chemostaten mit Glucose und Citrat als C‐Quellen untersucht. Die Erhöhung des pH‐Wertes bis zu einem für jede Verdünnungsrate charakteristischen Schwellenwert verursacht eine deutliche Erhöhung des Verbrauchs der zweiten, nicht limitierenden C‐Quelle Glucose und somit eine Verringerung des gemeinsamen Ertragskoeffizienten Y. Die Bestimmung der spezifischen Rate m des Erhaltungsstoffwechsels für Citrat und Glucose zeigte, daß der erhöhte Verbrauch der Glucose beim pH‐Schwellenwert außer durch eine erhöhte Produktbildung (SAKHAROVA et al. 1976) durch einen erhöhten Erhaltungsstoffwechsel verursacht wird. Die Aktivität von Schlüsselenzymen des Katabolismus (Glucose‐6‐Phosphatdehydrogenase, Isocitratdehydrogenase, Malatdehydrogenase, Pyruvatdehydrogenase) sowie der ATP‐Gehalt der Zellen nimmt beim pH‐Schwellenwert ab. Die bei einer Verdünnungsrate von D = 0,4 h−1 bestimmte ATPase‐Aktivität zeigt beim pH‐Schwellenwert einen erhöhten Wert.
Wachstum von Bacillus megaterium im Chemostaten unter alkalischen Bedingungen
Authors: Sakharova Z. V. , Shaforostova L. D. , Hilliger M. , Perewesjenzev W. P.
Published: July 2010

Die Kultivierung von Bacillus megaterium im Chemostaten unter alkalischen Bedingungen (pH > 7,0) zeigte, daß dieser Stamm in einem weiten pH‐Bereich wächst. Dieser pH‐Bereich verkleinert sich mit zunehmender Verdünnungsrate D im Chemostaten. Eine Erhöhung des pH‐Wertes über einen bestimmten, für jede Verdünnungsrate charakteristischen Schwellenwert hinaus verursacht schnelles und vollständiges Auswaschen der Kultur. Vergleichende Untersuchungen bei pH 7,0 und beim pH‐Schwellenwert zeigten beim pH‐Schwellenwert einen erhöhten Verbrauch der zweiten, nicht limitierenden C‐Quelle Glucose, eine Ausscheidung von organischen Säuren ins Nährmedium und eine Verringerung des gemeinsamen Ertragskoeffizienten Y für Citrat und Glucose. Die pro Gramm gebildete Trockenmasse verbrauchten Mengen von Phosphor und Stickstoff zeigten beim pH‐Schwellenwert im Vergleich zur Kontrolle (pH 7,0) keine Veränderung.
Testing of antiviral compounds against Mengo virus infection of mice A 2‐step procedure of in vivo screening
Authors: Veckenstedt Anneliese , Horn M.
Published: July 2010

A 2‐step procedure of screening of antiviral compounds in vivo is presented on the basis of standardized methods of both experimental examination and statistical analysis. The procedure uses the “rate of protection” R as the sole criterion of activity. In the first step, requiring a total of 40 mice, compounds with significant R are detected. Drugs producing R < 15% are discarded. Compounds eliciting R ⩾ 15%, without significance, are examined in a second step, using again 40 mice, to decide whether the protective activity becomes significant employing a greater number of animals. The procedure works with relatively less expense with regard of the number of animals used and the time required. The procedure can be applied to test systems based on lethal infections as well as to test models for which the use of the “rate of protection” is relevant.
Keratin decomposition by dermatophytes II. Presence of S‐sulfocysteine and cysteic acid in soluble decomposition products
Authors: Kunert J.
Published: July 2010

The dermatophyte Microsporum gypseum was grown on human hair in a mineral medium. Filtrates of cultures of various age were chromatographed on Sephadex gels and further characterized by chemical analysis and thin‐layer chromatography. The products of keratin decomposition were separated into two fractions. The first fraction formed 10 to 20% of the bulk and contained proteins low in sulfur content. The second, very wide fraction contained oligopeptides and polypeptides with molecular weights from several hundreds up to approximately 13,000 with a peak at 1,000–2,000 daltons. This fraction contained a relatively high amount of cystine, S‐sulfocysteine, and cysteic acid.

S‐sulfocysteine was present in the free state and also combined in peptides where its amount exceeded that of cystine. This supports the author's hypothesis on keratin decomposition by dermatophytes. According to this hypothesis, the fungus excretes sulfite which cleaves the disulfide bonds of keratin to cysteine and S‐sulfocysteine. The substrate, denatured by sulfitolysis, is then more easily digestible by fungal proteases.

Besides S‐sulfocysteine, comparable amounts of cysteic acid were found in all analyses. This compound most probably originated by air oxidation of sulfur amino acids in the alkaline cultivation fluid.
Influence of substrate moisture on the occurrence of fungi in birds' nests
Authors: Hubálek Z.
Published: July 2010

The nests of birds examined were identical to those of the previous study (HUBÁLEK 1976) but the number of the nests of Black‐headed Gull (11 samples only) was lower. Therefore, the total number was 186 nests in the collection „A”︁ and 84 in the collection „B”︁. The methods of investigation were the same as applied in the preceding study; water content of the samples was estimated in duplicate or triplicate by drying the material 3 hours at 105 °C, and expressed on the wet weight basis.
Mutagenesis in bacteriophage T 7. II. UV induced mutagenesis
Authors: Meyer M. , Witte W.
Published: July 2010

UV induced mutagenesis of bacteriophage T 7 was investigated by using a forward mutation system (host range system) and a back mutation system (amber system). The results indicate a dependence of mutation of T 7 after UV irradiation only on the rec gene controlled functions of the bacterial host. The functions controlled by pol and uvr genes have no influence. Among other types of mutations UV irradiation leads to transitions from AT to GC.
Das anodisch wandernde thermolabile Antigen (ATA) von gramnegativen Bakterien: Seine molekulare Heterogenität und seine chemische Zusammensetzung
Authors: Reissbrodt R. , Kemmer G. , Seltmann G.
Published: July 2010

The anodically‐moving thermolabile antigen (ATA) of gram‐negative bacteria represents a glycolipoprotein. In aqueous solution ATA exhibits heterogeneity of the molecular size, the range varying between 2 · 104 and 8 · 105 Daltons. In the molecular range between 5 · 104 and 8 · 105 all the molecular states give precipitation lines with the corresponding antisera.

It could be shown that all the molecular states of ATA are formed by different aggregation of the same subunit with a molecular weight of approximativly 22 000.
Variability of polyploid strains of Candida scottii in accumulation of riboflavin in the medium
Authors: Imshenetsky A. A. , Kondratieva T. F.
Published: July 2010

Polyploid strains of Candida scottii show a higher spontaneous and UV‐induced variability in accumulation of riboflavin in the medium than the original haploid strain. UV irradiation affects the formation of variants and induces those which accumulate more riboflavin than any of the most productive variants resulting from spontaneous variability. In the polyploid strains the frequency of plus‐variants increases. Therefore, polyploid strains of C. scottii are advantageous for selection processes.
Physiologie und Biochemie der Streptomyceten IX. Hydrolyse von Cyclohexyl‐, Kohlenhydrat‐ und Arylester durch eine Carboxylesterase aus Kulturen von Streptomyces hygroscopicus JA 6599
Authors: Reuter G. , Hüttner R.
Published: July 2010

Carboxylesterase in cell‐free extracts of Streptomyces hygroscopicus was characterized with cyclohexylacetate and β‐penta‐acetyl‐D‐glucose as substrates. After concentrating the enzyme, activity with α/β‐methyl‐4‐O‐propionyl‐L‐mycarosid as substrate was also observed. The influence of enzyme effectors was studied. Esterase activity was also found in the culture filtrate of. S. hygroscopicus.
Abhängigkeit der spezifischen Wachstumsrate von der Ammoniumkonzentration bei Escherichia coli ML 30
Authors: Bergter F. , Schumann H. , Koburger M.
Published: July 2010

The transient behaviour of ammonium limited continuous cultures of E. coli ML 30 led to the hypothesis that the bistability of pyruvate formation primarily is caused by a bistability of the ammonia metabolism. Therefore, a function μ([NH+4]) should be expected different from that of MONOD type. Measurements of the specific growth rate during washout of continuous cultures at different ammonium concentrations and at such low cell concentrations that the changes in the ammonium concentration of the medium could be neglected, showed a complex function with a relative minimum near 2 mg/1 NH+4. This function allows bistability of the ammonium concentration in an ammonium limited continuous culture. The results are discussed on the basis of the two systems of ammonia assimilation found in prokaryotic cells.
Some characteristics of two morphological mutants of Nostoc linckia induced by nitrosoguanidine
Authors: Ladha J. K. , Kumar H. D.
Published: July 2010

The blue‐green alga Nostoc linckia was treated with nitrosoguanidine and two classes of morphological mutant clones were isolated. One class shows certain abnormal phenotypic features of vegetative cells, spores, and heterocysts. It has increased heterocyst frequency and impaired growth rate. The other class exhibits an altered heterocyst spacing pattern. Both classes of mutants have reduced nitrogenase activity.
Glycinabhängigkeit von Staphylococcus aureus‐Stämmen
Authors: Voigt W. , Seltmann G.
Published: July 2010

Glycine dependent Staphylococcus aureus var. bovis strains (TSCHÄPE and RISCHE 1971) were tested for their ability to grow on glycine containing and glycine deprived media. We observed glycine dependence only in minimal media. In complete media the strains grew in absence of glycine

Testing the ability of some glycine precursors we found that in minimal media glycine could be replaced by threonine and in some cases by serine. One mutant (Gly 100 Glyox.r.) was able to metabolize glyoxylate instead of glycine

Aspartic acid was metabolized in presence of glycine. Using 14C‐aspartic acid we detected 14C‐glycine and 14C‐threonine. Presumably the bacteria metabolize aspartic acid to glycine via threonine.
Enzymes of carbohydrate metabolism in Coprinus cinereus (C. lagopus sensu LEWIS)
Authors: Fawole M. O.
Published: July 2010

This report describes the detection by spectrophotometric assays of all the enzymes involved in the breakdown of glucose to pyruvate via the EMBDEN‐MEYERHOF‐PARANAS pathway as well as some enzymes of the hexose monophosphate pathway in cell‐free extracts of Coprinus cinereus.
Reinigung von DNS‐Polymerase aus Proteus mirabilis
Authors: Nüske R. , Bieber J. , Wähnert U. , Venner H.
Published: July 2010

Aus Proteus mirabilis PG 273 wird durch mechanischen Aufschluß, Fällung mit Streptomycinsulfat, Autolyse und fraktionierte Fällung mit Ammoniumsulfat eine DNS‐Polymerase gewonnen. Ihre weitere Reinigung wird durch fraktionierte Alkoholfällung und Chromatographie an DEAE‐Cellulose erreicht. Die enzymatischen Eigenschaften des Präparates werden untersucht. Das Enzym gibt eine de novo‐Synthese von poly‐dAT, wie auch DNS‐Polymerase I aus Escherichia coli. Allerdings sind die Reaktionsprodukte noch dialysabel. Es kann nachgewiesen werden, daß es sich um eine DNS‐Polymerase I handelt.

Vergleichsuntersuchungen mit einer polA‐Mutante zeigen, daß das Aufarbeitungsverfahren auch zur Isolierung von Restmengen bakterieller DNS‐Polymerase I geeignet ist.
Fruchtkörper‐bildende Myxobakterien in Böden Brasiliens
Authors: Dawid W.
Published: July 2010

Aus 5 Großgebieten Brasiliens wurden 36 Bodenproben entnommen und nach vier verschiedenen Isolierungsmethoden auf Fruchtkörper‐bildende Myxobakterien untersucht. Je Bodenprobe wurden 100 Einzelproben angesetzt, insgesamt 3636.

Es wurden 19 verschiedene Fruchtkörper‐bildende Myxobakterien‐Arten isoliert und nach BERGEY (MCCURDY 1974) bestimmt. Sie gehören folgenden 7 Gattungen an: Myxococcus mit 5 Arten, Archangium mit 3 Arten, Cystobacter mit 2 Arten, Polyangium mit 4 Arten, Melittangium mit 1 Art, Stigmatella mit 2 Arten. Chondromyces mit 2 Arten.

Zu den häufigsten und weitverbreiteten Myxobakterien gehören die Arten M. fulvus, M. coralloides und A. gephyra, zu den selten beobachteten die Arten A. flavum, Stigm. erecta, Stigm. aurantiaca, Ch. apiculatus und Ch. pediculaius.

Artenzahl und Häufigkeit der gefundenen Myxobakterien werden in Beziehung zur Isolierungsmethode und zum Herkunftsgebiet der Bodenproben gesetzt.
Fine structure of imbibed sclerotial cells of Claviceps purpurea (Fr.) Tul revealed by freeze‐etching
Authors: Streiblová Eva , Rýc M. , Kybal J.
Published: July 2010

The fine structure of the cortex of the natural sclerotium of Claviceps purpurea was studied. The cell wall of sclerotial cells is thickened due to overproduction of the fibrillar component of the wall. The intercellular spaces of the cortex tissue form a continuous system which is apparently instrumental in mediating communication between the growing sclerotium and the external milieu. The cytoplasmic membrane of imbibed sclerotial cells carriers abundant signs of secretory activity. Secretion vesicles, the content of which is discharged into external space, apparently contain exo 1,3‐glucanase. Cytoplasmic vesicles migrating toward the plugged pores of the thickened septa apparently involve hydrolase secretion too. Spherosomes with lipid content are a predominant component of the cytoplasm of sclerotial cells. The activity of the membrane systems of imbibed cells indicates that the mobilization of lipids sets in only after activation of the hydrolases. Findings of phagocytosis of lipid granules by vacuoles are relatively frequent so that lipolysis might proceed in the vacuoles. Alkaloids could not be detected with the aid of freeze‐etching.
Virus‐like particles in yeast: Isolation and infectivity
Authors: Nesterova G. F. , Kärner J. , Soom Yo. , Kozlova T. M.
Published: July 2010

Virus‐like particles containing electron dense cores are seen in thin sections of intact and degenerated cells of a thermosensitive (ts) strain of Candida tropicalis. A particulate fraction not present in wild‐type cells has been isolated from the ts cells disrupted by pressure. The particles are 80‐120 nm in diameter. Empty particles with a central cavity are observed. The method of infecting mating pairs of Saccharomyces cerevisiae by partially purified particles is described.
Characterization of the virulent actinophage S2
Authors: Klaus S. , Süss F. , Juch C. , Hauck A.
Published: July 2010

The virulent actinophage S2 isolated from soil infects Streptomyces hygroscopicus 6599, S. lividans 66, and S. levoris 1331. Morphology of S2 was studied by electron microscopy. Influence of growth medium and temperature on multiplication of S2 has been studied qualitatively. S2 is more sensitive to UV irradiation on strain 66 than on 1331. In contrast to UV, hydroxylamine mutagenesis delivered 9 stable ts mutants which belong to 3 complementation groups.

Most of the ts mutations isolated on 1331 were found to be host dependent. 8 of 9 mutants were found to be able to grow at 40 °C on strain 66 but none of them on 1331. Moreover 2 of the mutants were found to be much more heat sensitive in 6599 than in 1331, as indicated by the changes in half‐life temperatures.

The latent period of S2+ depends on temperature and germination state of the spores. Under optimal conditions we found 140 min. Ts2 and ts7 have been classified as a late and ts17 as an early mutant.