bluuebunny/crossref_metadata_2025_split huggingface dataset:
Alteration of interaction with virulent bacteriophage Tal during differentiation of Thermoactinomyces vulgaris
Authors: Kretschmer Sigrid 
Published: July 2010

AbstractDuring its life cycle Thermoactinomyces vulgaris 1227 and 1261 substrate mycelium showed three modes of interaction with the virulent phage Tal, each expressed at a distinct morphological stage. Primary mycelium arising from spores 50 min after start of germination was the only stage which propagated phages upon infection. However, infection of growing secondary mycelium or of late sporulation stages resulted in a loss of phage. The lack of phage production upon infection of growing secondary mycelium was not related to sporogenesis, since it appeared already 3.5 hours before the beginning of sporulation. If phages were added to the secondary mycelium at the beginning of spore formation, the phage genome became integrated in the developing spores in a heat‐stable state. Allowing outgrowth of these prophage‐carrier spores, phages were produced similarly as in germ tubes arising from normal spores infected at the time of inoculation.The growing secondary substrate mycelium was characterized by competence for the uptake of exogenous DNA. Since at the stage of competence phages were neither produced nor was phage DNA trapped, the earlier reported lack of transfection in undisturbed differentiating T. vulgaris is now understandable.
Elektronenoptische Untersuchungen zur in vitro‐Wirkung von Dipyridamol auf das Pseudorabiesvirus
Authors: Zöpel P. 
Published: July 2010

AbstractDipyridamole at a concentration of 50 μM/ml displays no activity on adsorption and penetration of pseudorabies virus in chicken embryonal cells. Furthermore, first stages of virus replication take place within the nucleus, whereas incomplete virus cores defective in DNA content are found within the nucleoplasm at times when the regular viral replication has been finished in controls. Defective pseudorabies virus particles lacking in DNA‐content of the core, can be observed at the end of normal replication time. Consequently, the antiviral activity of dipyridamole may be due to blocking of the synthesis or of the incoporation of infectious viral DNA into the virus core.
Physiologischer und zellbiologische Charakterisierung des Proteasebildners Thermoactinomyces vulgaris während Langzeit‐Kultivation im Rührfermentor
Authors: Kretschmer S. , Körner D. , Strohbach G. , Klingenberg P. , Jacob H.‐E. , Gumpert J. , Ruttloff H. 
Published: July 2010

AbstractThe physiological behaviour of Thermoactinomyces vulgaris — producing a thermostabile serine‐protease — was analyzed during fermentation. During 38 h the consumption of nutrients and oxygen as wll as the rates of macromolecular and protease synthesis were measured. The morphological and ultrastructural changes of the mycelia were also studied.The mycelia grew exponentially for about 5 hours. After a short lag and a second slower growth phase, growth continued about linearly until the end, as was indicated by a constant rate of incorporation of labelled thymidine. However, at the same time a changing portion of hyphae — up to 45% — underwent lysis. According to the changing ratio of growing and lysing material, regarding the physiological activity of the culture the fermentation process could be divided into 4 periods.The formation of the protease started at the transition to the slow growth phase and continued linearly. The ability to produce the protease was attributed to a mycelium being formed after the shift down caused by limitation of supply of utilizable nitrogen compounds. The end of protease production 10 h later was correlated to a drastic decrease of the respiratory activity of the mycelia, probably caused by exhaustion of easily utilizable carbohydrates.
Mikrobielle Verwertung von Mischsubstraten
Authors: Weide H. 
Published: July 2010

AbstractDecomposition of substrates by heterotrophic microorganisms is accomplished in natural biotopes such as in soil and in waters, on or in macroorganisms but also in laboratory and industrial biotopes. The interest of man in these processes is manifold. Starting with the division of substrates into three groups of simple substrates, complex and mixed substrates with or without solid particles their qualitative and quantitative occurrence in nature and their significance in biotechnology will be discussed. In the decomposition of these substrates their utilization by pure cultures or mixed populations is to be exactly distinguished. Simple growth curves, di‐ or polyauxy, sequences of decomposition of simple substrates of a mixed substrate, population changes and successions are only some of the phenomena occurring in this process. The pathways of catabolism are subjected to manifold regulations on the three levels of stoichiometric regulation, the regulation of enzyme activity and the regulation of enzyme synthesis. In natural biotopes there is hardly a constant substrate supply over a longer period. That's why certain mechanisms of regulation are permanently acting. Thus the ‘normal’ physiological state for microorganisms is characterized by permanent transition situations – called ‘transients’. These reactions are also applied to many biotechnological processes.
Lysogenie und lysogene Konversion bei methylotrophen Bakterien I. Nachweis des lysogenen Zustandes des fakultativ methanolassimilierenden Stammes Acetobacter MB 58/1 und Charakterisierung seines temperenten Phagen MO 1
Authors: Wünsche L. , Fischer H. , Kiesel B. 
Published: July 2010

AbstractLysogeny could until now not be shown for methylotrophic bacteria or for Acetobacter. In this paper we demonstrate the lysogenic state in a methylotrophic strain of the genus Acetobacter. The responsible temperate phage MO 1 belongs to group A of BRADLEY's classification system and contains double stranded DNA. Phage MO 1 was characterized by the following properties: Host range, sensitivity against environmental factors, serological behaviour, burst size, and latent period in one‐step growth experiments, and especially by its response to inducing factors.
Elektronenmikroskopische Untersuchung an Komplexen von DNA mit der Restriktionsendonuclease SalGI
Authors: Johannssen W. 
Published: July 2010

AbstractThe binding properties of the type II restriction endonuclease SalGI to the plasmid DNA pGW 10 has been investigated by electron microscopic studies. Samples were spread by the BCA technique. In the presence of magnesium, SalGI binds as dimers and tetramers to the specific recognition site 5′‐G‐T‐C‐G‐A‐C‐3′ and with lower rate to the sequence 5′‐G‐T‐C‐A‐A‐C‐3′, which represents the recognition site of the restriction endonucleases Hind II and Hinc II.
Preparation and partial characterization of Xanthomonas oryzae phytotoxin
Authors: Dubey R. S. 
Published: July 2010

AbstractA synthetic medium containing ammonium nitrate, urea, D‐glucose, glycerol, and sodium glutamate was developed for growth of Xanthomonas oryzae and preparation of its phytotoxin. Culture filtrates and partially purified toxin preparations caused blight symptoms when inoculated in leaves of 30 days old rice plant cv. T(N) I. Toxin elicited quicker response than living cells. This activity was due to a non‐dialysable, partial acid and heat labile glycopeptide. There was a sharp decrease in activity when culture filtrates and crude toxin preparations were heated at 100°C for 30 min. Maximum activity was observed in pH range of 6.0–7.0 and a gradual loss at lower pH (5.0–3.0) and higher pH values (8.0–10.0). Unlike living cells which caused continuous lesion enlargement, toxin inoculation caused maximum attainment of lesion length within 4–6 weeks. Toxin preparation in concentration of 45 μg glucose/ml failed to evoke response.The study demonstrates that the purified toxin being easy in storage and causing quicker response than living cells when inoculated in rice leaves, may be used to screen rice varieties for bacterial blight resistance.
Protoplastenfreisetzung und Regeneration des Ascomyceten Hypomyces ochraceus (PERS.) TUL
Authors: Riemay K. H. , Ellrich Silvia , Tröger R. 
Published: July 2010

AbstractA rapid and convenient method for producing protoplasts from 3 d old mycelium of the ascomycete Hypomyces ochraceus is described. The procedure involves a Helix pomatia enzyme preparation and sucrose (20%) for stabilization. Pretreatment with disulfide bond reducing agents reduced the amount of viable protoplasts. Formation of protoplasts and different stages of regeneration were observed by phase contrast microscopy. There was only one type of true regeneration from protoplasts to hyphae in 15–30% gelatine medium by direct forming a germ tube from the original protoplast. Cytological events and physiological conditions are discussed.
Fluoride‐induced filaments of Erwinia carotovora
Authors: Gashe B. A. , Grula M. M. 
Published: July 2010

AbstractSodium fluoride induces filamentous growth of Erwinia carotovora when it is grown in liquid media containing aspartic acid only as the sole source of nitrogen. It is proposed that a stable complex of F−‐Mg2+‐enzyme and PO, resulting in Mg2+ deficiency and consequent inability of E. carotovora cells to oxidize aspartic acid normally, is responsible for the formation of filaments in the presence of fluoride ions.
Growth ofCandida albicanson artificialD‐glucose derivatives
Authors: Hrmová M. , Šturdík E. , Košík M. , Gemeiner P. , Petruš L. 
Published: July 2010

AbstractGrowth ofCandida albicanson artificial D‐glucose derivatives (amino‐, methyl‐, acylglycosides and N‐acetyl‐D‐glucosamine derivatives) was examined with the aim to find new inducers of the mycelial growth form. For representatives of particular groups (α‐D‐glucopyranosylamine, D‐glucose and N‐acetyl‐D‐glucosamine) some physiological (growth, doubling time, specific growth rate, oxygen uptake and CO2production, respiration quotients), biochemical (dry weight yield, protein content, ethanol production), and morphological parameters (length‐width quotient, volume, percentage of budding cells) of cultures in different growth phases were determined with regard to the type and concentration of carbon source. The results obtained may be valuable for studies of the structure‐utilization relationships of carbohydrate derivatives as well as for the elucidation of yeast‐mycelial transition inCandida albicansinduced by unphysiological hexoses degradable intracellularly.
Verbesserung der Y‐Werte bei Wachstum von Hansenula polymorpha auf Methanol durch simultane Verwertung von Glucose
Authors: Müller R. , Markuske K. D. , Babel W. 
Published: July 2010

AbstractThe simultaneous utilization of methanol and glucose by Hansenula polymorpha MH20 was investigated in chemostat (C‐limited) cultivation. The mixed‐substrate utilization results in biomass yields which are greater up to 20 to 25% as expected assuming an additive growth on both substrates. This is referred to as an auxiliary‐substrate effect. Additionally, methanol can be utilized at higher growth rates in the presence of glucose compared to those obtained on this substrate alone. The extend of the auxiliary‐substrate effect and the optimum ratio of substrates to reach this effect depend on dilution rate. The greatest stimulation in yield is obtained at D ∼ 0.1 h−1, after raising the dilution rate this effect diminishes. At a rate of 0.1 h−1 the optimum mixed‐substrate ratio of methanol: glucose is 7: 1(g). By increasing the growth rate the ratio changes toward glucose and reached a value of 1:1 (g) at D = 0.3 h−1. This change in the optimum ratio correlates with diminution in yield coefficient of methanolp accomanying an increase in growth rate > 0.15 h−1. Energy balances of the utilization of the single substrates are used for interpretation of these results. From this it is evident that methanol does not play the role of an energy‐rich substrate in the metabolism of yeast. Rather glucose is the energy‐providing substrate in this combination.
Inhibition of photosystem II of nitrogen‐fixing blue‐green alga Nostoc linckia by the rice‐field herbicide benthiocarb
Authors: Singh R. K. , Singh B. D. , Singh H. N. 
Published: July 2010

AbstractEffects of rice‐field herbicide benthiocarb (S‐(4‐chlorobenzyl)‐N,N‐diethyl thiolcarbamate) was studied on the nitrogen‐fixing blue‐green alga Nostoc linckia. The herbicide caused inhibition of growth and heterocyst formation, an increase in intensity of photoacoustic signals, and a four‐fold reduction in oxygen evolution, but did not affect dark O2‐uptake. The inhibition of growth and heterocyst formation was relieved by 500 μg/ml glucose. A Het−Nif− mutant of Nostoc muscorum failed to show an increase in reversion frequency after treatment with 10 μg/ml benthiocarb for 1 hr.
Effects of cycloheximide on the temperature profile ofSacharomyces cerevisiae
Authors: Madeira‐Lopes A. , van Uden N. 
Published: July 2010

AbstractTmax, the maximum temperature for growth ofSaccharomyces cerevisiae, decreased linearly with increasing concentrations of cycloheximide added to the medium, to about 20 °C at 2.5 μg ml−1. In this concentration range thermal death was not enhanced. The ARRHENIUS plot of growth was shifted to lower temperatures as a function of the cycloheximide concentrations and became dissociated from the ARRHENIUS plot of thermal death. It was concluded that the target site of cycloheximide, the cytoplasmic ribosome, is not identical with the physiologicalTmaxsite ofS. cerevisiaeand that the binding of cycloheximide to its target sites is strongly enhanced by the temperature.
Growth measurements by monitoring light scattering of a filamentous blue‐green alga which does not give uniform and stable suspension in culture vessels
Authors: Adhikary S. P. 
Published: July 2010

AbstractIt has been tried to adapt the light scattering technique to measure the growth of a filamentous blue‐green alga Westiellopsis profilica JANET which does not give stable and uniform suspension during its growth in culture vessels. Experiments were conducted to make stable suspensions of the organism and the results on the scattering and spectral studies were compared with that of Microcystis sp. which gives a uniform and stable suspension in culture vessels.Some conventional experiments were performed to show that the growth of the blue‐green alga, Westiellopsis prolifica does not run with the rate of pigment metabolism. It has also been observed that the alterations in size, shape, swelling and shrinkage and average cell characteristics of the alga resulted from alterations in physical and chemical characteristics of the culture media, significantly change the scattering values without much or any change in their growth rate in term of dry weight values.
Double or triple sets of replication functions as inverted and direct repeats on in vitro reconstructed streptococcal MLS resistance plasmids
Authors: Behnke D. , Klaus S. 
Published: July 2010

AbstractIn vitro rearrangement of plasmid pDB102 together with comparative studies of other streptococcal plasmids allowed the localization of replication and copy control functions on sequences which were present on pDB102 and its naturally occurring ancestor pSM19035 as duplicates in inverted orientation. Evidence is presented that neither the presence of duplicate replication regions nor their arrangement in inverted orientation was essential for plasmid survival. Among the in vitro reconstructed plasmids were several that stably carried two or three sets of replication and copy control functions either as inverted or direct repeats or both. A copy control mutation is described which led to a tenfold increase of copy number over that of the naturally occurring plasmid pSM19035.
Uncoupling of respiration in turimycin fermentations
Authors: Effenberger W. , Müller P. J. , Bocker H. 
Published: July 2010

AbstractResults furnish evidence for a partial uncoupling of respiration at conditions of phosphate limitation in turimycin fermentations. The uncoupling was primarily caused by the high intracellular ATP hydrolase activity and probably also by the CN‐resistant respiration. The results support the idea that high dephoshorylating enzyme activities may have a regulatory effect on the secondary product biosynthesis.
Wirkung supraoptimaler Temperaturen auf Wachstum und Entwicklung einer Brennereihefe I. Wachstum und Entwicklung der HefeSaccharomyces cerevisiae, Stamm 193 bei diskontinuierlicher Kultur
Authors: Mavrina L. , Pozmogova I. , Schade W. 
Published: July 2010

The influence of supraoptimal temperatures on a distillery yeast was investigated. Supraoptimal temperatures below 40 °C reduced the biomass production but did not cause the death of the culture after several generations.At 42° to 44 °C the yeast cells lost their ability of propagation after one or two generations without showing an intracellular deficit of phosphorus‐containing repairing components. The separation of daughter cells from mother cells was rendered more difficult. The appearance of abundand doubled cells was characteristic. The contents of RNA and protein decreased to 41% or 80%, respectively. Rates of14C‐uracil and14C‐leucine incorporation showed that the synthesis of RNA was repressed stronger than that of proteins by the high temperature treatment at 42° to 44 °C. The effectivity of energy metabolism of the cultivated yeast cells was low at supraoptimal temperatures. The yeast showed a strongly enhanced activity of fermentation and an accumulation of polysaccharides.
Use of D‐glucosamine and 2‐deoxyglucose in the selective isolation of mutants of the yeast Lipomyces starkeyi derepressed for the production of extracellular endodextranase
Authors: Laires A. , Spencer‐Martins I. , van Uden N. 
Published: July 2010

AbstractThe glucose analogues 2‐deoxyglucose and D‐glucosamine repressed the production of extracellular endodextranase in the yeast Lipomyces starkeyi. Though both analogues were successfully used for the selective isolation of derepressed and hyperproductive mutants, 2‐deoxyglucose proved to be superior to D‐glucosamine with respect to effective concentration and the avoidance of background growth.
Production of oxalic acid by some fungi infected tubers
Authors: Faboya O. , Ikotun T. , Fatoki O. S. 
Published: July 2010

AbstractOxalic acid (as oxalate) was detected in four tubers commonly used for food in Nigeria – Dioscorea rotundata (White yam), Solanum tuberosum (Irish potato), Ipomoea batatas (Sweet potato), and Manihot esculenta (cassava). Whereas healthy I. batata had the highest oxalic acid content, healthy M. esculenta contained the lowest. When all tubers were artificially inoculated with four fungi — Penicillium oxalicum CURIE and THOM, Aspergillus niger VAN TIEGH, A. flavus and A. tamarii KITA, there was an increase in oxalate content/g of tuber tissue. The greatest amount of oxalate was produced by P. oxalicum in D. rotundata tuber. Consistently higher amounts of oxalate were produced by the four fungi in infected sweet potato tuber than in any other tuber and consistently lower amounts of oxalate were produced by the four fungi in Irish potato tuber. Differences in the carbohydrate type present in the tubers and in the biosynthesis pathway are thought to be responsible for variation in the production of oxalate in the different tubers by the four fungi used.
Isolierung und Rekonstitution des Alkan‐Monooxygenase‐Systems der Hefe Lodderomyces elongisporus
Authors: Schunck W.‐H. , Riege P. , Honeck H. , Müller H.‐G. 
Published: July 2010

It is generally assumed that the first step of alkane degradation in several yeast strains and bacteria is catalyzed by a monooxygenase system containing cytochrome P‐450 as the terminal oxidase and a NADPH‐cytochrome P‐450 reductase as the electron transfer component. To prove this hypothesis both proteins were purified to homogeneity from the microsomal fraction of the alkane‐assimilating yeast L. elongisporus and reconstituted in vitro.The cytochrome P‐450, having a specific content of 12–17 nmoles/mg protein turned out to be a typical member of this class of hemoproteins with respect to the molecular weight (53 500) and spectral properties.The reductase component with a molecular weight of 79000 contains FAD and FMN as prosthetic groups.The recombination of the hemoprotein and the flavoprotein results in an enzyme system which catalyzes the monoterminal hydroxylation of hexadecane.The activity of the reconstituted enzyme system is remarkably stimulated by nonionic detergents, suggesting the requirement of an additional lipid factor. The possible importance of other electron transfer systems and of substrate transport is discussed with respect ot the function of the alkane monooxygenase system under in vivo conditions.
The effect of varying concentrations of Mg2+ and ATP upon the kinetic behaviour of dihydroxyacetone kinase from the methanol‐assimilating yeast Candida methylica
Authors: Hofmann K. H. , Babel W. 
Published: July 2010

AbstractThe phosphorylation of dihydroxyacetone by means of the enzyme dihydroxyacetone kinase (DHAK) is a key reaction in the assimilation of methanol in yeasts. In the present paper the influence of varying concentrations of Mg2+ ions and ATP upon the reaction rate of DHAK from Candida methylica is described and the regulatory consequences for the assimilation of methanol by yeasts are discussed.
Konjugativer Plasmidtransfer von A‐, B und H‐Streptokokken auf N‐Streptokokken
Authors: Riemelt I. , Kirchhübel W. , Malke H. 
Published: July 2010

AbstractPlasmid‐mediated resistance to erythromycin and chloramphenicol was successfully transferred from group A, B and H streptococci to group N streptococci by a process akin to conjugation. The results showed that plasmids from streptococcal groups other than N were able to replicate in lactic streptococci as well.The transfer experiments were carried out by using a membrane filter mating technique. Four of the five plasmids used (pSM15346, pSM10419, pIP501, and pEL1) were transferred at frequencies ranging from 10−1 to 10−8 transconjugants per donor colony‐forming unit. The highest transfer frequencies were obtained when S. pyogenes strain 15346 (pSM15346) served as the donor strain. The identy of transconjugants was verified by testing for the presence of unselected markers of the recipient strains, and both transduction and transformation were ruled out as the mechanisms of transfer.
Effect of a focal articular defect on cartilage deformation during patello‐femoral articulation
Authors: Wong Benjamin L. , Sah Robert L. 
Published: July 2010

AbstractThe objective of this study was to determine cartilage strains near, and in apposition to, a focal defect during patello‐femoral articulation. Bovine osteochondral blocks from the trochlea (TRO) and patella (PAT) were apposed, compressed 12%, and subjected to sliding under video microscopy. Samples, lubricated with synovial fluid, were tested intact and then with a full‐thickness defect in PAT cartilage. Shear (Exz), axial (Ezz), and lateral (Exx) strains were determined locally for TRO and PAT cartilage. For articulation with a focal defect, the strain amplitudes of PAT cartilage near the surface were ∼2–8× lower in Exz and ∼1.4× higher in −Ezz than intact PAT cartilage. At 20% depth, Exz and Exx for PAT cartilage with a focal defect were ∼2× and ∼10–25× higher than intact PAT, respectively. For TRO articulating against a focal defect, Exz and −Ezz near the surface and at 20% depth were ∼2–4× lower than that for articulation against intact cartilage. The results elucidate dramatic region‐specific changes in strain due to lateral motion. In these regions, such altered cartilage mechanics during knee movement may cause focal defects to extend by induction of damaging levels of strain to bordering regions of cartilage. © 2010 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 28:1554–1561, 2010