bluuebunny/crossref_metadata_2025_split huggingface dataset:
Wirkung von Polyenantibiotica und ihrer Perhydroderivate auf intakte Zellen und Protoplasten der Hefe Candida guilliermondii
Authors: Haupt I. , Spata L. , Thrum H. , Weber H. 
Published: July 2010

AbstractPerhydroderivatives of polyene antibiotics have a much lower activity against eukaryotic cells than the polyene antibioitics itself. Bacterial cells are normally resistant against most polyene antibiotics and their perhydroderivatives. In earlier experiments with wall less L‐form cells of Escherichia coli we have shown that the bacterial cell wall may be responsible for the resistance of the intact bacterial cells against polyene antibiotics and their perhydroderivatives by masking internal target sites.In the present paper we studied the effect of polyene antibiotics and their perhydroderivatives on intact cells and protoplasts of Candida guilliermondii. Our experiments have shown that most of the perhydroderivatives studied had a lower a against intact cells as well as protoplasts than the corresponding polyene antibiotics. This means that in the case of eukaryotic cells the cell wall as a penetration barrier cannot mainly be responsible for the low activity of perhydroderivatives. The results are compared with those obtained previously with intact cells and protoplast type L‐form cells of E. coli.
Structure and function of the conidiospore pigments of Penicillium cyclopium
Authors: Ha‐Huy‐Ké  , Luckner M. 
Published: July 2010

AbstractThe cell wall of mature, green condiospores of Penicillium cyclopium WESTLING contains at least two pigments: A green chromoprotein which is extractable by means of formic acid or liquified phenol and a black insoluble pigment. Both fractions after long term treatment with boiling conc. HCl leave black amorphous residues which, due to their chemical and physico‐chemical properties, belong to the group of melanins. The chemical structure of these melanins is still unidentified. No degradation products typical for indol‐type or catechol‐type melanins have so far been detected.During spore maturation parallel to an increase of pigmentation (determined by remission), the melanin residue left after acid hydrolysis of spores increases. The mature, dark green spores of the wild type strain contain about 40% melanin, the yellow‐green spores of the mutant aux‐glu 1 about 36%. The unpigmented spores of mutant res‐eth 1 prossess a melanin content of only about 5%. This value is nearly the same as that found in hyphae, which in all strains are yellowish‐brown. The heavily pigmented condia of the wild type strain are about 100‐times less sensitive to UV‐radiation compared with the unpigmented spores of the mutant res‐eth 1. The reduced sensitivity indicates that, as with other microorganisms, the conidia pigments of P. cyclopium are protective components of the spores.
Determination of the biological parameters of bacterium‐phage complexes
Authors: Gáspár S. , Rontó Gy. , Müller G. 
Published: July 2010

AbstractThe authors present a method of measurement and evaluation for continuous cultures of bacteria infected by virulent phages. By the comparison of the model describing the phage‐bacterium interaction and their own experimental data they determined the following biological parameter values characterizing the interaction: the adsorption rate (μ), the expectation of the latency period (T) and its standard deviation (σ), the time required for lysis (d), the infection efficiency (n) and the average burst size (C). The parameters were used or the determination of optimal cultivating conditions (maximum phage yield).
Photodynamische Wirkung von Quinacrin auf Bakterien
Authors: Jacob H.‐E. 
Published: July 2010

AbstractThe acridine dye quinacrine (QA) was tested with regard to the photodynamic action on bacteria (Proteus mirabilis, Escherichia coli). The absorption maximum of the yellow dye QA ist in contrary to the photodynamically active dyes methylene blue (MB) an thiopyronine (TP) situated in the short wave region of the visible spectrum. Using for illumination a common light source – they have in general a weak emission in the short wave region – relatively high concentrations of QA are necessary for photodynamic action, and the difference between photodynamic inactivation and toxic effect is small. Using the light source XBO 500 with nearly equal emission in the range from 400 to 700 nm, a distinct photodynamic action of QA results. Comparing the photodynamic action of QA with those of MB and TP, QA has a low photodynamic effect, and the kinetics of inactivation of bacteria with QA is completely different from those obtained with the dyes MB and TP.
Regulative influence ofo‐aminobenzoic acid on the biosynthesis of nourseothricin in cultures ofStreptomyces nourseiJA 3890b IV. Bistability of metabolism and the mechanism of action of aminobenzoic acids
Authors: Gräfe U. , Bocker H. , Thrum H. 
Published: July 2010

AbstractUsing the semi‐continuous cultivation technique we could establish that specifically inStreptomyces nourseiJA 3890b during growth on a medium supplied with D,L‐alanine, NH4+, and maize starch there are two different phenotypes of the organism and stationary states of metabolism, respectively.The expression of either the metabolic state 1 with an enhanced capacity to oxidative deamination of alanine via the NAD+‐dependent alanine dehydrogenase or the metabolic state 2 which may be characterized by the preferred use of ammonium ions via the NADP+‐dependent glutamate dehydrogenase was shown to depend strongly on the conditions of inoculum cultivation.When the amino acid permeases were derepressed by cultivating the inoculum cells on amino acid media. probably due to the defective mechanism of negative feedback control of amino acid influx in this strain an abnormously high uptake of alanine was observed that, consequently, was correlated to the enhanced oxidation of this amino acid as well as to the intensive production of ammonia within the cell. This overproduction of cellular NH4+seems to bring about the subsequent repression of biosynthetic glutamate dehydrogenase and so on the accumulation of ammonia autocatalytically may rise up (metabolic state 1).On the other hand, if the influx of alanine was kept low and the NADH oxidation was less efficient, respectively, or when there was high cellular activity of glutamate dehydrogenase the level of ammonia never did exceed the repressory limit and, accordingly, the expression of the metabolic state 2 was observed.Switching‐over of metabolic flux from the state 2 towards the state 1 can be brought about either by increasing the level of nitrogen sources in the medium or by adding buffers pH > 7.5. In contrast, decrease of cellular level of NH4+was shown to induce the transition of metabolic state 1 into the state 2. This can be achieved not only by limitation of nitrogen source but also by adding different aminobenzoic acids and, alternatively, effectors of membrane function (short‐chain alcohols). inhibitors of cytochrome oxidases (sodium azide, potassium cyanide), heavy metal (Fe++)‐ chelating agents (catechol, 2.2′‐dipyridyl,o‐phenanthroline). ß‐alanine, and buffers pH < 7. This suggests that these effectors are capable of preventing the abnormously high influx of amino acids as well as its wasteful catabolism within the cell ofS. nourseiJA 3890 b.Therefore. it seems likely that by this way the aminobenzoic acids and similar effectors can diminish the catabolite repression or inhibition of secondary metabolism by cellular excess of some nitrogen compounds in good agreement with its well‐known stimulatory action on the biosynthesis of the antibiotic nourseothricin in this strain.
Regulation of Neurospora crassa nucleosidases by some environmental factors
Authors: Mattoo A. K. , Dandekar A. M. , Trivedi J. P. , Majmudar G. H. , Patel D. M. 
Published: July 2010

AbstractEnzymic cleavage of N‐glycosidic bonds of AMP, GMP, and inosine by the cell‐free extracts of Neurospora crassa has been studied. The enzymic activities with these substrates appear to be discrete from one another. The levels of these enzymes in the cell vary with age, and are dependent upon the inoculum size, aeration rate, and phosphate level in the medium. Glucose (or ribose) controls the phosphate‐mediated repression of all the three nucleosidases of this fungus.
Verlauf und Beeinflussung der Autolyse von Hypomyces ochraceus m 359
Authors: Riemay K.‐H. , Weise M. 
Published: July 2010

AbstractGrowth and natural autolysis of the ascomycete Hypomyces ochraceus were investigated in shake cultures by measuring dry weight, pH value, and uptake of carbohydrate. The alkaline autolysis resulted in maximum loss of 53% of dry weight during an incubation period of 35 days. Early autolysis was induced by limitation of oxygen, increasing temperature, addition of peracetic acid, and sodiumacide. Autolysis is discussed to be derived from deficiency of energy.
Ultracytochemical charactrization of non‐specific acid phosphatase activities in Saccharomyces cerevisiae
Authors: Böhm K. J. , Unger E. 
Published: July 2010

AbstractGlutaraldehyde prefixation causes a considerable inactivation of the acid phosphatase of yeast protoplasts in dependence on the duration of aldehyde influence. Lead ions necessary for ultracytochemical demonstration effect a still stronger inhibition of enzymatic activity. Prefixation, however, protects the enzyme from further inhibition by lead.At pH 4.4 in intact cells acid phosphatase activities are mainly localized in the periplasmic space and in vesicles fused with the plasma membrane. The cell wall and cytoplasm usually remain free of reaction products. On the cell surface activities are found in form of globular lead deposits. At pH 5.2 and 6.3 the periplasmic activity appears decreased compared to that at lower pH values and the intracellular activity is increased.The plasma membrane of protoplasts is completely free of precipitates. The intracellular activity sites of protoplasts (cisternae of endoplasmic reticulum and/or Golgi‐like system, small vesicles, central vacuole, nuclear envelope) are the same as for intact cells.The occurrence of at least two forms of acid phosphatase in S. cerevisiae is deduced.
Effects of drugs that influence eucaryotic motile processes on motility of Cystobacter fuscus (Myxobacterales)
Authors: Heumann H.‐G. , Kühlwein H. 
Published: July 2010

AbstractCytochalasin B, dbcAMP and EGTA were found to inhibit the motility of Cystobacter fuscus completely whereas colchicine and cAMP only reduced velocity of movement.
Factors influencing the copy number of F‐like plasmids in Escherichia coli and Salmonella typhimurium
Authors: Pritchard J. J. , Lemoine V. Rodriguez , Rowbury R. J. 
Published: July 2010

AbstractThe copy numbers of Flac, four F‐like plasmids and pLT2 were estimated in two strains of Salmonella typhimurium and (for all except pLT2) one strain of Escherichia coli. For organisms grown in casamino acids minimal medium, the plasmids spanned a 7–8 fold range of copy number with ColB‐K98 having the highest copy number in each strain and R124 the lowest. The copy number of ColB‐K98 was substantially greater than 1 in each of the strains tested. There was no clear relation between the plasmid size and copy number, although the plasmids studied spanned only a narrow size range. The copy number of individual plasmids was slightly reduced or not affected at all by the presence of a second plasmid in the same strain. Derivatives harbouring each of the plasmids were grown in three different media to ascertain how plasmid copy number responds to changes in growth rate. For each plasmid, the copy number increased with decreasing growth rate. Extracts from each of the three strains harbouring ColB‐K98 contained two distinct plasmid species. One appeared to be about twice as large as the other and both were absent from Col− segregants.
Biochemical studies on sporulation in blue‐green algae I. Glycogen accumulation
Authors: Sarma T. A. , Kanta Swarn 
Published: July 2010

AbstractGlycogen accumulation in vegetative cells of Anabaena sp. is demonstrated to be a light‐dependent process. No glycogen accumulation is found in dark or in cultures supplemented with 10−5 M DCMU in light. Large quantities of glycogen acccumulate in cells undergoing sporulation and the amount increased with the onset of maturation of spores.
Effect of temperature on the transcription by bacteriophage T3‐induced RNA polymerase
Authors: Mann W. , Musielski H. , Laue R. , Michel S. 
Published: July 2010

AbstractBacteriophage T3‐induced RNA polymerase is rapidly inactivated at 42°C. Addition of T3 DNA delays this process for 30 s and reduces the rate with which the enzyme activity is lsot indicating that a labile binary complex between T3 DNA and polymerase must have been formed. The ternary complex between T3‐specific RNA polymerase, T3 DNA, and nascent RNA chains obtained when the enzyme is incubated with T3 DNA, GTP, ATP, and UTP is stable to heat (42°C) and only slowly inactivated by polyvinyl sulfate. The optimal temperature for the formation of polyanionresistant ternary complexes is 30°C while the elongation of T3 RNA chains proceeds fastest at 38°C.
Steroidumwandelnde Enzyme aus Mikroorganismen XII. Merkmale der Induktion der 4‐En‐3‐oxosteroid: (Akzeptor)‐l‐en‐oxidoreduktase in Nocardia opaca
Authors: Hörhold C. , Hüller E. , Rose G. 
Published: July 2010

Abstract17α‐Methyltestosterone and the corresponding 1(2)‐dehydrocompound (Dianabol) are efficient inducers of the 4‐en‐3‐oxosteroid: (acceptor)‐l‐en‐oxidoreductase from Nocardia opaca. After a lag period of 4 hours the enzyme activity increases rapidly. During the induction the steroids are completely metabolized causing a drastical drop of specific enzyme activity. Using a fixed induction time the optimal steroid concentration and the temperature characteristic were found out. The influence of the concentration of the steroid water suspension on the induction effect is discussed to be dependent on the velocity of the dissolving of the steroid particles.Chloramphenicol and streptomycin are powerful inhibitors of the induction process.
Reduktion von L‐Carnitin zu γ‐Butyrobetain durch Escherichia coli
Authors: Seim H. , Kleber H.‐P. , Strack E. 
Published: July 2010

AbstractDer Stoffwechsel des L(–)‐Carnitins wurde an einem aus Rattendarm isolierten Stamm von Escherichia coli und an E. coli K12 unter aeroben und anaeroben Bedingungen im Hinblick auf die Entstehung von L‐Carnitinmangel untersucht.Unter aeroben Wachstumsbedingungen unterlag das L‐Carnitinmolekül keinerlei Veränderungen. Auch unter anaeroben Bedingungen war L‐Carnitin nicht C‐ oder N‐Quelle, aber beide E. coli‐Stämme reduzierten L‐Carnitin zu γ‐Butyrobetain. Als weiterer Carnitinmetabolit wurde Crotonsäurebetain, nicht aber Trimethylamin, nachgewiesen. Die Bildung von γ‐Butyrobetain und Crotonsäurebetain war von der Art des Nährmediums und von der eingesetzten L‐Carnitinkonzentration abhängig und unterschied sich signifikant bei beiden E. coli‐Stämmen. Die L‐Carnitinreduktion wurde sowohl durch Elektronenakzeptoren der anaeroben Atmung, wie Nitrat und Trimethylamin‐N‐oxid, als auch durch Glucose und ein L‐Aminosäuregemisch, nicht aber durch Lactat und Succinat, gehemmt.
Cell wall regeneration of Candida spec. protoplasts
Authors: Popov E. , Reuter G. , Meyer H. W. 
Published: July 2010

AbstractA yeast of the genus Candida which is able to grow on n‐alkanes was characterized by biochemical investigations: Crabtree effect, inhibition of ammonium utilization by asparagine, changes in the concentration of polysaccharides mainly concentrated in the cell wall. The yeast was compared biochemically and electron‐microscopically with its pure protoplast population, and the regeneration of the cell wall was studied. In correspondence with the asynchronously developing accumulation of glucan and mannan, electron microscopical studies have first only revealed glucan fibrils. Matrix formation (mannan) occurs only in the second stage of regeneration. After a regeneration period of 9 hours, the polysaccharides in the former protoplast population reached the concentration of the period before enzymatic removal of the cell wall. A tube‐like structure observed by light microscopy during the early stages of regeneration is shown electron‐microscopically to consist of a fibrillar network without matrix. Between newly formed cell wall and plasma membrane, in some cells groups of large flat vesicles were found, whose fracture faces are free of particles. After protoplast formation the invaginations of the plasma membrane arrange themselves in rows one behind the other. These findings are supported by further evidence suggesting that the invaginations are structures on the basis of lipid domains.
Carbon and nitrogen nutrition of plant pathogenic fungi associated with basal stem rots of cowpeas, Vigna unguiculata (L) WALP in Nigeria
Authors: Oladiran A. O. , Oso B. A. 
Published: July 2010

AbstractPythium aphanidermatum, Rhizoctonia bataticola (syn. = Macrophomina phaseolina), Botryodiplodia theobromae, and two strains of Selerotium rolfsii readily utilized for growth the monosaccharides glucose, fructose and mannose, the disaccharides sucrose and maltose and the polysaccharides dextrin and starch. In addition, S. rolfsii grew appreciably well on carboxymethylcellulose (CMC). When filter paper (nature cellulose) was supplied as sole carbon source, it was decomposed by B. theobromae, S. rolfsii (SR2) and R. bataticola.In studies on nitrogen utilization, B. theobromae grew best on glutamic acid, P. aphanidermatum on glycine and the two strains of S. rolfsii on ammonium nitrate. R. bataticola utilized casein hydrolysate most effectively for growth. EDTANa2 was a poor nitrogen source for all the pathogens.
Dihydroxyacetone kinase of methanol‐assimilating yeasts. I. Regulation of dihydroxyacetone kinase from Candida methylica in situ
Authors: Hofmann K. H. , Babel W. 
Published: July 2010

AbstractIn order to investigate the control behaviour of dihydroxyacetone kinase of methanol‐grown Candida methylica under nearly physiological conditions kinetic and regulatory studies were carried out in situ. Yeast cells were made permeable to substrate and reaction products by treatment with Triton X‐100. Normal Michaelis‐Menten kinetics resulted in dependence upon the dihydroxyacetone concentration, both at the pH optimum of 7.6 and near the physiological pH‐value of 6.5. The Km obtained for dihydroxyacetone was 0.02 mm, independent of the pH‐value. The plots of dihydroxyacetone kinase activity as a function of the ATP concentration revealed complex kinetic characteristics with plateau regions. The maximum reaction rate was reached only after a lag time both at pH 7.6 and concentrations of ATP higher than 5 mm and at pH 6.5 and concentrations of ATP higher than 1.25 mm. Among a great number of tested metabolites no inhibitors of dihydroxyacetone kinase were found. Dihydroxyacetone kinase activity depending upon energy charge according to Atkinson exhibited curves of the U‐type. These results and further data concerning the regulation of other enzymes obtained with C. methylica and other yeasts were the basis to propose a preliminary overall model of fine control of the carbon and energy metabolism of methanol‐utilizing yeasts.
Bistability in a model of microbial product formation
Authors: Guthke R. , Knorre W. A. 
Published: July 2010

AbstractA mathematical model of continuous growth of microorganisms and product formation with growth inhibition by the product is presented and investigated. Two stable steady states occur due to the competition of growth and product formation for the same limiting substrate. One stable state is characterized by a high product concentration but low biomass concentration whereas the other state is characterized by the opposite relations. The first steady state is approached by oscillating kinetics. Both phenomena are consistent with frequently observed kinetic instabilities in industrial fermentation processes.
Hyphomicrobium as a component of the aquatic microflora — morphological and physiological studies on two strains
Authors: Moaledj K. 
Published: July 2010

AbstractAspects of the morphology, metabolism and physiology of two oligocarbophilic strains of Hyphomicrobium (H4K and S5K), isolated from the Plußsee, were studied. Both strains are able to grow on mineral salts media without added organic carbon sources. Strain H4K grows well even in double distilled water. The two strains cannot grow on mineral media in the absence of atmospheric CO2. No growth occurred also in air purified of organic carbon, in spite of the presence of CO2. On the contrary, there is good growth in the presence of some organic compounds and without atmospheric CO2, i.e., heterotrophic metabolism without CO2 assimilation is possible. Growth was enhanced in a methanol atmosphere, and by the addition of yeast extract, methylamine, peptone and glucose. In nutrient solutions containing acetate or formate as carbon source, growth of H4K begins only after an adaptation period of ca. 4 weeks.
Naphthochinon‐Antibiotica aus Streptomyces lateritius. I. Fermentation, Isolierung und Charakterisierung der Granatomycine A, C und D
Authors: Fleck W. F. , Strauss D. G. , Prauser H. , Fleck W. F. 
Published: July 2010

AbstractThe fermentation and isolation procedures of the antibiotic granatomycin produced by Streptomyces lateritius are described. Furthermore, the producing strain ZIMET 43627 and the main constituents of granatomycin will be characterized. Granatomycin is a red‐violet pigment antibiotic of the naphthoquinone type. The physicochemical properties of granatomycin resemble those of granaticin. The antibiotic can be isolated from culture filtrates and from the mycelium by extraction with lower aliphatic alcohols. It can be purified by gel filtration methods. Granatomycin displays antimicrobial activity, particularly against grampositive and gramnegative bacteria, and antiviral activity against fowl‐plaque‐virus in mammalian cells. Granatomycin is useful in selection of resistant mutants of bacteria and viruses with decreased virulence but high immunogenity suitable for use as life vaccines against infection diseases. The physicochemical properties of the main constituents of granatomycin studied confirm the identity of granatomycin C with granaticin and the identity of granatomycin D with dihydrogranaticin. Granatomycin A is identical with the well‐known semisynthetic methylester of dihydrogranaticin. Therefore, the production of granatomycin A is the first possibility to produce this derivative of granaticin biosynthetically.
Kupfer‐II‐komplexe N‐heterocyclischer Formylisothiosemicarbazone mit antimikrobieller und β‐Lactamasen inhibierender Wirkung
Authors: Heinisch L. , Fleck W. F. , Jacob H.‐E. 
Published: July 2010

AbstractThe synthesis of copper(II)‐complexes from quinoline‐2‐ or quinoxaline‐2‐aldehyde‐isothiose‐micarbazones in pyridine and the elucidation of their structure are described. Some of the new substances exhibit an inhibitory action on growth of grampositive bacteria, especially Bacillus subtilis (ATCC 6633), furthermore in vitro the β‐lactamase I action is inhibited. Using penicillin‐resistant Staphylococci as test strains a strong penicillin‐synergistic action was discovered.
Degradation of steroids by microorganisms. XVIII. The reversibility of steroid‐l‐dehydrogenation during microbial side chain degradation of sterols by Nocardia
Authors: Komel R. , Groh H. , Hörhold C. 
Published: July 2010

AbstractThe aerobic side chain degradation of sterols often leads to mixtures of 1,4‐diene and 4‐ene compounds. By an additional anaerobic step a practically complete reverse reaction of the steroid‐1‐dehydrogenation occurs yielding only the corresponding 4‐ene compound.