bluuebunny/crossref_metadata_2025 huggingface dataset:
Eigenschaften der Rubredoxin‐Reductase aus dem alkanassimilierenden Bakterienstamm Acinetobacter calcoaceticus
Authors: Claus R. , Asperger O. , Kleber H.‐P.
Published: July 2010

In Acinetobacter calcoaceticus läßt sich nach Wachstum auf langkettigen n‐Alkanen eine Rubredoxin‐Reductase nachweisen, welche spezifisch den Elektronentransport von NADH über Rubredoxin – nicht aber über Ferredoxin oder Adrenodoxin – zum Cytochrom c katalysiert. Die Cytochrom c‐Reduktion der etwa 30fach angereicherten Rubredoxin‐Reductase ist der eingesetzten Rubredoxin‐Reductase‐Konzentration und Rubredoxinmenge proportional. Neben Dichlorphenolindophenol (Km = 2,5 × 10−6 mol/l) is Hexacyanoferrat (Km = 5,5 × 10−6 mol/l) ein wirksamer Elektronenakzeptor. Der Km‐Wert für NADH wurde in Cytochrom c‐Reduktionstest als auch mit Hexacyanoferrat als Elektronenakzeptor einheitlich mit 1,1 × 10−4 mol/l bestimmt.

Das pH‐Optimum der Rubredoxin‐Reductase liegt bei pH 7,7 (0,01 mol/l Phosphatpuffer) bzw. 8,5 (0,05 mol/l Tris/HCl‐Puffer). Die Reaktionsgeschwindigkeit der Cytochrom c‐Reduktion wird durch Erhöhung der Molarität des Phosphatpuffers vermindert. Zusatz von FAD – nicht aber von FMN – steigert die Reductaseaktivität. FAD scheint die prosthetische Gruppe der Rubredoxin‐Reductase zu sein.

Der Einfluß verschiedener Verbindungen (Ionen, SH‐Reagenzien, Hemmstoffe der Atmungskette u. a.) auf die diaphoretische Aktivität und die Cytochrom c‐Reduktion wird untersucht.
Steroidumwandelnde Enzyme aus Mikroorganismen XI. Reversibilität der Dehydrierungsreaktion der Steroid‐1‐Dehydrogenase aus Nocardia opaca
Authors: Groh H. , Komel R. , Deppmeyer V. , Atrat P. , Hörhold C.
Published: July 2010

Highly purified preparations of the 4‐en‐3‐oxosteroid: (acceptor)‐1‐en‐oxidoreductase from Nocardia opaca have been investigated in both types of reactions: 1.2‐dehydrogenation of the 4‐en‐3‐oxo‐derivative and 1.2‐hydrogenation of the 1.4‐dien‐3‐oxo‐derivative. It was not possible to separate the hydrogenating activity from the dehydrogenating activity by affinity chromatography, disc electrophoresis, SDS‐electrophoresis, and isoelectric focusing techniques. The pure enzyme preparation is discussed as only one FAD depending protein acting in response to the system as a dehydrogenase as well as a reductase.
Nitrate respiration of Klebsiella pneumoniae on amino acids, especially on serine
Authors: Kikuchi S. , Ishimoto M.
Published: July 2010

Anaerobic growth on an amino acids mixture in the presence of nitrate of a strain of K. pneumoniae isolated from soil depended on the presence of serine in the mixture. This organism grew on serine as sole carbon source under anaerobic conditions in the presence of nitrate but not in its absence. Glycylglycine could replace serine. Serine was degraded to acetate, formate, pyruvate, acetone and acetoin with formation of nitrite under these conditions. These products were practically not different from those formed from glucose. Resting cells decomposed serine also in the absence of nitrate forming butanediol and a large amount of formate in place of decreased amounts of acetate and pyruvate. These cells also anaerobically decomposed alanine to products similar to those from serine and phenylalanine to phenylacetate and formate only in the presence of nitrate. Valine was not catabolized under the same conditions. Serine was decomposed to pyruvate and ammonia in the crude extract in the presence and absence of nitrate, indicating participation of serine dehydratase in its breakdown. Phenylalanine appears to be decomposed to phenylpyruvate by transamination coupled to glutamate oxidation and then to phenylacetate and formate. Little growth on serine under anaerobic conditions in the absence of nitrate may be accounted for by the small gain of ATP in the anaerobic breakdown of serine by this organism.
Light microscopic investigations on lysozyme‐ and penicillin‐induced morphological changes in Erysipelothrix rhusiopathiae and on propagation of its protoplast type L‐form
Authors: Gumpert J. , Todorov T. , Toshkov As
Published: July 2010

Although lysozyme and penicillin are different in their molecular action on cell wall murein they produce similar morphological changes in Erysipelothrix rhusiopathiae grown on agar media. 2,000–5,000 μg/ml lysozyme and 0.1–1 IU/ml penicillin induce filament formation. Filaments are able to divide in rods, which shows that only cross wall formation and separation are inhibited. Higher doses of lysozyme (10,000 μg/ml) and penicillin (>1 IU/ml) inhibit cell wall synthesis and induce L‐form growth. The propagation of this protoplast type L‐form was investigated by microphotographic series in phase contrast microscope during L‐form induction and in the stable L‐form state. In both cases L‐form cells propagate by formation and growth of small granular elements of about 0.2–0.6 μm in diameter, which spread in different directions in the agar medium. The multiplication process may be explained by the plasticity and flexibility of the L‐form cell and its cytoplasmic membrane and by the structural and functional interaction between the “folded chromosome” and the surrounding cytoplasm.
Effect of certain herbicides on survival, growth, and nitrogen fixation of blue‐green alga Anabaena doliolum Bharadwaja
Authors: Kapoor Kamal , Sharma V. K.
Published: July 2010

Growth and fixation of nitrogen were retarded in Anabaena doliolum when grown on elemental nitrogen in presence of four different herbicides. The alga was found to be intolerant to these chemicals under nitrogen fixing conditions even in low concentrations. An inhibition of photosynthesis has been regarded as the main basis of herbicidal activity besides other interactions.
Virus adaptation to host cells: The non‐classical modification of phage T3
Authors: Krüger D. H. , Hansen Sigrid , Schroeder Cornelia
Published: July 2010

Bacterial virus T3 undergoes host‐controlled modification which is not based on “classical” processes of DNA modification and restriction. The adsorption and thus the growth of T3 on Escherichia coli W cells (E. coli K12 derivative) decisively depends on the host strain on which the virus was previously propagated. Depending on the modification conferred to the virus by its last host, its efficiency of plating (e.o.p.) on E. coli W varies by six orders o magnitude between 10−7 and 10−1. This does not reflect the appearance of T3 host‐range mutants, but a fully reversible modification of genotypically unchanged T3 wild‐type phage.

The behaviour of T3 in the described host system constitutes a second case of so‐called nonclassical modification and restriction (KRÜGER et al. 1977, Molec. gen. Genet. 153, 107–110) of bacteriophages, Non‐classical modification (protein modification) is additive to and independent of DNA modification and restriction as demonstrated with the ocr− phage T3/R7. – Furthermore, our results suggest that the adsorption specificity of T3 is determined by at least two independent genetic factors; in both of these factors T3 differs from T7.
Resistenz gegen Quecksilber und Cadmium bei Staphylococcus aureus unterschiedlicher ökologischer Herkunft
Authors: Witte W. , van Dip Nguyen , Hummel Ruth
Published: July 2010

For S. aureus isolates of different ecological origin, MIC‐values for HgCl2 and CdSO4 were determined on a synthetical medium. Only strains from outbreaks of suppurative infections in hospitals were resistent to mercury, strains from infections in out‐patients, from healthy human nasal carriers, from infections in cattle, sheep, chicken, and pigs were sensitive.

Resistance to cadmium occurred in strains from man and from cattle but not in strains from sheep, chicken, and pigs. The majority of the cadmium‐resistant strains was also resistant to penicillin, but some strains were only resistant to cadmium and sensitive to antibiotics.
Inhibitor studies of phage T4 wild‐type and mutant DNA polymerases. III. Distamycin A, actinomycin D, adriamycin, daunomycin and ethidium
Authors: Jantschak J. , Schroeder Cornelia , Jantschak J.
Published: July 2010

Adriamycin, daunomycin and ethidium, intercalating drugs which bind to double‐ as well as single‐stranded DNA, inhibit phage T4 antimutator mutant CB121 DNA polymerase more strongly than the T4 wild‐type and the mutator L98 polymerase. In contrast, all three enzymes are inhibited equally by distamycin A and actinomycin C. The latter two inhibitors bind only to double‐stranded DNA.
Survival and mutagenesis in UV‐irradiated phage: Multi‐hit kinetics of mutation induction and lack of indirect induction by infection with UV‐irradiated phage of error‐prone repair
Authors: Krauss Gabriele , Mennigmann H.‐D. , Kaplan R. W. , Mennigmann H. D.
Published: July 2010

The paper is concerned with the question of whether Weigle‐reactivation (WR) and Weigle‐mutagenesis (WM) can be indirectly induced by infection with UV‐irradiated phage. Experiments neither with phage λ of Escherichia coli nor with phage χ of Serratia marcescens show such induction‐In this respects phage DNA differs from F′‐DNA or Hfr‐DNA; possible explanations are discussed.

In both systems clear plaque mutations can also be induced by UV without irradiation of the host cells; they appear, in unirradiated and irradiated host cells, with an increase in frequency which is greater than proportional to the UV dose. It is concluded that mutation induction of phage in the unirradiated host cells is due to a low level constitutive mutagenic repair; this could either be due to “spontaneous” induction of the mutagenic SOS‐function or it could be a mechanism different from this one. Host irradiation would give rise to additional activity by the induced SOS‐function leading to WR and WM.

It is further concluded that deviation of the induction kinetics from a linear dose‐dependence is not due to the necessary induction of SOS‐functions.
Leaching of a silicate and carbonate copper ore with heterotrophic fungi and bacteria, producing organic acids
Authors: Kiel Hildegard , Schwartz W.
Published: July 2010

Leaching of metals with carbon‐heterotrophic microorganisms and organic acids as active agents has been performed with Timna copper ore containing 1.1% copper as carbonates and silicate and with some other metal oxides. Aspergillus niger surface cultures on a 14% sucrose fermentation medium yielded 87.3% of total copper from a 10% suspension within 2 weeks of leaching. On sulfite liquor as an industrial waste product A. niger solubilized 73.8% Cu within 4 weeks. In percolators with 14% sucrose medium up to 1780 ppm copper were found in solution. In leaching experiments with a sea water medium containing 7% sucrose only 684 ppm Cu were soluble. Leaching with lactobacilli containing whey yielded 83.4% of the total copper in 4 weeks.
Einfluß der Kohlenstoffquelle auf die Reservestoffbildung von Candida spec. H
Authors: Brückner B. , Tröger R.
Published: July 2010

Various aspects of the carbon energy reserve metabolism of Candida spec. H on glucose in comparison to its metabolism on hydrocarbons were studied in this article. In the absence of nitrogen for growth cells undergo several changes in their chemical composition. The content of protein and nucleic acids decreases rapidly. At the same time on the glucose medium glycogen and trehalose were markedly accumulated, whereas lipid accumulation was only slight. On the hydrocarbon substrate both carbohydrates and lipid were increased. Also the difference between the fatty acid composition of Candida spec. H when grown on glucose and on n‐alkanes was studied. The results were discussed.
Orotsäure – ein Wuchsfaktor für Pasteurella multocida
Authors: Flossmann K.‐D. , Höfer M. , Erler W. , Feist H.
Published: July 2010

Orotsäure stellt einen Wuchsfaktor für die Vermehrung von Pasteurella multocida dar. Sie ist mit abnehmender Wirksamkeit durch andere Pyrimidine ersetzbar (Uracil > Cytosin » Thymin). Untersuchungen mit 2‐, 6‐, 7‐, U‐14C‐ bzw. 5‐3H‐Orotsäure beweisen, daß die Wirkung der Orotsäure in ihrer zentralen Stellung im Pyrimidinstoffwechsel zu sehen ist. Die Radioaktivität des Pyrimidinringes wird in den Pyrimidinbasen der Bakterienzelle wiedergefunden, während die Aktivität der Carboxylgruppe (7‐14C‐Orotsäure) hauptsächlich in Bernsteinsäure, einem im Kulturfiltrat auftretenden Metaboliten des Kohlenhydrat‐ und Aminosäure‐Stoffwechsels, auftritt. Die Untersuchungen sprechen dafür, daß die Pyrimidinbiosynthese bei P. multocida in den Anfangsschritten, vermutlich infolge ungenügender CO2‐Bereitstellung, gestört ist. Für eine Vermehrung in vitro genügen etwa 0,1 mMol Orotsäure pro 1 Nährmedium.

Auf Grund des Einbaus des Pyrimidinskeletts in die Bakterienzelle eignet sich am Pyrimidinkern markierte Orotsäure bestens als radioaktives Material zur Markierung von P. multocida‐Zellen.
Geomicrobiological leaching of the minerals by Thiobacillus ferrooxidans and organic agents
Authors: Teh G. H. , Schwartz W. , Amstutz C. C.
Published: July 2010

Laboratory investigations confirm that it is possible to leach tin from synthetic minerals like stannite, kesterite, stannoidite, herzenbergite, ottemannite and berndtite, and from natural tin minerals which include stannite, cassiterite and varlamoffite, in the presence of Thiobacillus ferrooxidans, and with organic agents of biological origin, especially oxalic acid and oxalic‐citric acids mixture.

Over a leaching period of 35 days with 0.5% pulp density, initial pH of 2.5, using minus 0.16 mm size fraction at 32°C, as much as 54.45, 72.66, 97.13, and 31.30% Sn were extracted from synthetic stannite, kesterite, stannoidite and natural stannite, respectively. Varlamoffite, found in the dried, leached residues of the tin sulphides, provides evidence that bacterial action can be responsible for the genesis of supergene varlamoffite.
Invagination of cytoplasmic membrane as the initial event of cross wall formation in actinomycetes
Authors: Strunk C.
Published: July 2010

Early stages of sporogenesis of Streptomyces vinaceus were studied by the aid of ultrathin serial sections. It could be demonstrated that the process of cross wall formation starts with an invagination of the cytoplasmic membrane.
Studies on air‐borne fungi at Qena II. Diurnal fluctuations
Authors: Abdel‐Fattah H. M. , Moubasher A. H. , Swelim M. A.
Published: July 2010

The air‐borne fungi displayed diurnal periodicities. The total count of fungi exhibited double‐peaked pattern, one at 6 a.m. and the other at 18 p.m. (the higher).

Aspergillus diurnal activities were almost parallel to those of total fungi.

Cladosporium showed one main peak at 18 p.m. Penicillium and Alternaria displayed some pattern of diurnal activity and their maxima were observed.
Struktur der Zellwandpolysaccharide in der Futtereiweiß‐Hefe Candida spec. H. IV. Struktur der alkalilabilen Oligosaccharide im Mannan‐Protein‐Phosphat‐Komplex
Authors: Grimmecke H.‐D , Reuter G.
Published: July 2010

Mild alkaline degradation of the proteophosphomannan (PPM) under conditions that effect β‐elimination of the residues, O‐glycosidically bound on serine and threonine, release mainly mannose, glucose, mannobioses and mannotrioses with the same structures as those obtained by acetolysis of the polysaccharide component of the PPM. Methylation analysis and paper chromatography demonstrated the structural heterogeneity of the tetra‐, penta‐ and hexasaccharide fractions containing 1,2‐ and 1,6‐linked and 1,2,6‐branched manno‐oligosaccharides. Methylation analysis and acetolysis, paper chromatography and analysis of the carbohydrate composition of the oligosaccharide fractions DP 7–12 and DP 15–19 demonstrated inner core region like structures containing 1,2‐ and 1,6‐linked mannose, 1,2,6‐ and 1,3,6‐branchpoints and N‐acetyl‐d‐glucosamine.
Analysis of morphogenesis of the nocardioform organism Oerskovia xanthineolytica
Authors: Kretschmer S.
Published: July 2010

Depending on the nutritional and physicochemical conditions of growth the shape of Oerskovia xanthineolytica varied within a broad range. In different exponentially growing cultures five morphological types could be distinguished. In liquid cultures with increasing growth rate Oerskovia grew either as rods, filaments or branched filaments, whereas for the agar‐microcultures pseudomycelia, but under reduced aeration mycelia were typical. The morphogenetic parameters of each type were determined, such as frequencies of septation and cell separation and – since wall extension was found to occur by the synthesizing activity of elongation sites (e‐sites), their frequency, position and elongation rate as well.

The cell length varied between 1 and about 20 μm, roughly correlated to the specific growth rate, but was also influenced by the composition and the consistence of the medium. The longest cells were found within the faster growing cultures, forming branched filaments, mycelia or pseudomycelia. During transition to the stationary growth phase these forms fragmented into rods by increase of the frequency of septation and cell separation.

Increased cell length was accompanied by a reduced frequency of e‐site formation which was compensated by an enhancement of their synthesizing activity. The rate of envelope synthesis varied with the morphological type from 0.12 to 9.60 μm/h. In agar‐microcultures these values were much higher than in liquid media.

In liquid cultures the e‐sites preferentially were situated at one (rod) or the 2 cell poles (filaments), but during faster growth additional e‐sites were formed within the cylindrical part of the envelope, thus leading to branching. In pseudomycelia the e‐sites were formed laterally at the poles. In mycelia the poles did not receive e‐site‐activity, which instead occured remote from the cell poles, also causing branching. This means that branching is either the result of the formation of more than two (up to 7) e‐sites per cell (fast growing liquid cultures) or of a specific lack of transforming the poles into e‐sites, (weakly aerated agar‐cultures).

The separation of sister cells was correlated to the transformation of poles into e‐sites.
Abbau von Steroiden durch Mikroorganismen XVII. 11β‐ und 12β‐Hydroxylierung von (20S)‐20‐Carboxy‐1,4‐pregnadien‐3‐on durch Cochliobolus lunatus
Authors: Hörhold C. , Rose G. , Kaufmann G.
Published: July 2010

(20S)‐20‐Carboxy‐1,4‐pregnadien‐3‐one was hydroxylated by Cochliobolus lunatus in positions 11β and 12β. The two novel compounds were characterized by means of UV‐, IR‐ and NMR‐spectroscopy. The possibility to use microbial degradation products of the 20‐carboxy‐pregnane type for the partial synthesis of glucocorticosteroids is discussed.
Genetic analysis of prophage effects on heteroimmune superin fection in Serratia marcescens
Authors: Steiger H.
Published: July 2010

Plaque formation of phage χ on Serratia marcescens strain HY normally depends on the presence of either a ψ or y prophage in the indicator bacteria. Bacterial ink mutants allowing χ growth in the absence of either prophage were isolated from the doubly cured strain HY (ψ, y)−. By means of a χ mutant, named gdy, an active participation of χ in antagonizing inhibition of its own growth on HY (ψ, y)−) was demonstrated. The gdy mutation is closely linked to gene cIII coding for the χ repressor. The prophages ψ and y enable χ to grow undisturbed probably by modifying the χ DNA during replication in such a way that it is not susceptible to the ink+ effect. Whereas χ grown on HY (ψ, y)−ink− gave only rare productive infections of HY (ψ, y)−, ψ and y grown on the same strain were fully infective.

The interference exerted by a χ prophage on vegetative propagation of y is based upon a multicomponent mechanism, the interference being removed, or diminished by mutations residing either inside or outside of the χ prophage. The responsible phage gene iny+ is dominant over its mutant allele iny−; hence it codes for a diffusible product. Both on the vegetative and the prophage genome iny is located near gene lI responsible for lysogenic conversion of bacteria to non‐adsorption of χ.

The restriction‐modification system of HY is not involved in the growth inhibition of χ by HY (ψ, y)−. Contrary to the other phages used in this work y is refractory to restriction.
Zusammenhang zwischen Koloniemorphologie und Polysaccharidgehalt in zellwandmodifizierten Mutanten von Candida spec. „H”︁
Authors: Kölblin R. , Birkenbell S.
Published: July 2010

The polysaccharide content of cell wall glucan and mannan from 40 morphological mutants was determined by a modified method according to MÄNDL et al. (1969) and discussed with reference to morphology of the colonies. A connection between morphology of the colonies and the content in high‐molecular mannan was stated: Morphological mutants with a significantly higher or lower content in high‐molecular mannan in comparison with the wild strain are characterized by marked changes in morphology of the colonies. In contrast to this, the content in low‐molecular mannan and glucan has no influence on the morphological development of a colony.
A novel extracellular proteinase from Bacillus pumilus
Authors: Okotore R. O. , Akinrimisi E. O. , Ojo M. O.
Published: July 2010

Bacillus pumilus NCTC AII6/73 produces a novel extracellular alkaline proteinase whose optimum is pH 9.5. The purified product from ion‐exchange chromatography (DEAE‐cellulose) was resolved into two bands by polyacrylamide‐sodium dodecyl sulphate (SDS) gel electrophoresis. These had approximate molecular weights of 15.6 × 103 and 11.1 × 103 daltons, respectively, and a high content of glycine and proline, comprising roughly 50% of the total amino acid residues.
Transformation of tomatidine by Gymnoascus reesii
Authors: Belič I. , Gaberc‐Porekar V. , Sočič H. , Žaelj M.
Published: July 2010

Gymnoascus reesii degrades tomatidine after 120 h to products no more detectable by TLC. The intermediates, produced after 48 h of incubation, were identified as tomatanin‐3α‐ol, tomatidone, 4‐tomatiden‐3‐one, 1‐tomatiden‐3‐one, 1,4‐tomatadien‐3‐one, and probably 15 β‐hydroxytomatidone.

The possible degradation pattern of tomatidine by Gymnoascus reesii is discussed.
Interaction of bacteriophage T7 with Hind‐endonuclease‐producing Haemophilus influenzae Rd cells
Authors: Krüger D. H. , Hansen Sigrid , Hartmann M.
Published: July 2010

In order to test the influence of the restriction endonucleases of Haemophilus species on in vivo DNA restriction of phage T7 and its close relative T3 as well as to determine whether the anti DNA restriction effect of the T7 and T3 ocr+ gene is also expressed in Haemophilus cells, we studied the interaction of T7 and T3 with Haemophilus influenzae serotypes Rd and Rc and Haemophilus parainfluenzae. The results show that T7 and T3 are unable to infect these bacterial species because they do not adsorb to the cells.
Arthrobacter globiformis — ein neues hefelytisches Bakterium
Authors: Blechschmidt D. , Gohr C. , Tröger R.
Published: July 2010

A bacterium capable to lyse viable yeast cells was isolated from compost enriched with baker's yeast cells and was identified as Arthrobacter globiformis.

The yeast lytic enzyme complex produced by shaking culture was precipitated with ammonium sulfate, dialyzed and lyophilized. The crude residue contained β‐glucanase and α‐mannanase, yet not chitinase. Optimale carbon sources in the culture medium for a high enzyme synthesis were 0.5% β‐glucan for the production of β‐glucanase, resp., 3% α‐mannan for the production of α‐mannanase. Addition of 10% whole died baker's yeast cells to the culture medium effected similar results.

The crude enzyme residue released among other things spheroplasts from cells of the yeast Pichia membranaefaciens, Metschnikowia pulcherrima, Hansenula anomala and Candida guilliermondii “H”. However, it did not or only weakly lyse viable cells of the yeasts Rhodotorula rubra, Rhodosporidium toruloides and Sporobolomyces roseus.

The mutants of Candida guilliermondii “H” with modified glucan, resp., mannan concentrations in the cell walls did not indicate differences in their susceptibility to lysis.
A new major outer membrane protein in derivatives of Escherichia coli carrying the virulence plasmid ColV‐K94
Authors: Moores Jane C. , Rowbury R. J.
Published: July 2010

Strains of Escherichia coli K12 harbouring ColV‐K94 contain a new major outer membrane protein of molecular weight ca. 33,000. The new protein resembles the Omp A protein in that (1) it is trypsin‐sensitive in membrane preparations and (2) it is not murein‐associated. The new protein cannot, however, replace the Omp A protein as a functional receptor for the phages K3 and Tull*, for colicin L or for efficient conjugation with F‐like donors. The new protein is apparently not a transfer component and is produced by cells unable to produce colicin. Labelling experiments with minicells suggest that the new protein is one of two major plasmid‐encoded membrane proteins.
The temperature profile of growth, death and yield of the starch‐converting yeast Lipomyces kononenkoae
Authors: Spencer‐Martins I. , van Uden N.
Published: July 2010

A strain of Lipomyces kononenkoae earlier proposed for industrial starch bioconversion was found to have a dissociative temperature profile. The ARRHENIUS plot of sustained exponential growth displayed a single branch between the optimum (32–33°C) and the maximum (about 35°C) temperature for growth while the extrapolated ARRHENIUS plots of growth and thermal death intersected at a biologically non‐significant value. The yield of L. kononenkoae on glucose did not decrease at supraoptimal temperatures while the associative yeast Saccharomyces cerevisiae suffered yield decreases above the optimum temperature for growth with increasing temperature.
Theoretische Bestimmung energetischer Wirkungsgrade der mikrobiellen Kohlenstoffsubstratwandlung und Vergleich mit experimentellen Werten an Phasenkulturen
Authors: Heinritz B. , Stichel E. , Rogge G. , Bley T. , Glombitza F.
Published: July 2010

The phenomenological description of microbial substrate conversion is possible by connecting energy and material balance equations.

The change of free enthalpy of microbial substrate conversion was determined on the basis of exact material balance equations. A simultaneous determination of heat production allowed to calculate the energetic efficiency of microbial growth processes. In addition to this the change of free enthalpy by microbial substrate conversion was standardized by the free standard formation enthalpy of biomass. Both quantities were used for comparing microbial combustion of several substrates into biomass. Comparable with the concept of substrate combustion enthalpy standardized by the combustion enthalpy of biomass an optimal strategy of mixing different substrates can be deduced from energy and material balance equations on the basis of theoretic consumption coefficients.

Besides the energetic efficiency the binding state of the substrate is important in the search for optimal substrate mixing ratios. This could be shown by experimental work. Thus, the fermentation systems sucrose/yeast, paraffin/yeast, and sucrose/paraffin/yeast were studied using synchronous populations produced by the method of phased cultures. The investigations of real fermentation systems confirm the theoretical predictions on special conditions.
Genetische Rekombination in Mutanten des Anthracyclin‐Bildners Streptomyces griseus
Authors: Schumann G. , Fleck W. F.
Published: July 2010

It was found that genetic recombination occurs if two marked strains of Streptomyces griseus (leukaemomycin‐producing strains. IMET JA 3933 and IMET JA 5142) are grown together in mixed cultures on semisolid media. The crossing techniques used and the method for carrying out selective analysis were essentially the same as those described by HOPWOOD (1967, 1972). The parent strains used for crosses were marked with single or double nutritional requirements and with mutations for drug resistance. The crosses are quite self‐sterile, yielding only in one combination stable prototrophic recombinants at a low frequency (10−5 to 10−6). The majority of recombinants behaved as stable haploid genotypes. A series of four‐point crosses of different types of auxotrophs was carried out. The results of these experiments do not provide sufficient data for constructing a chromosome map, but provide basic information on the possibilities of genetic analysis of the production of anthracycline antibiotics. The majority of crosses performed were not fertile at 28°C but, surprisingly, in some crosses carried out at 34°C viable colonies were detected on minimal media at frequencies from 10−3 to 10−2.
Zellteilung und Makromolekülsynthesen in auswachsenden Sporen einer temperatursensitiven filamentösen Mutante von Bacillus subtilis
Authors: Prösch S. , Hecker M. , Mach H. , Mach F.
Published: July 2010

A temperature sensitive mutant of Bacillus subtilis SB 19, strain ts 33‐6 was characterized. This strain grows at 46°C (restrictive temperature) with reduced intensity without septation processes. Under restrictive conditions DNA‐ and RNA‐synthesis are remarkably reduced. DNA, however, is synthesized continuously under restrictive conditions causing the formation of multinuclear filaments. Septation, induced at permissive temperature, is not prevented under restrictive conditions. That means that under restrictive conditions initiation of septation is blocked whereas formation of septa can be observed. Shift‐up experiments have shown that the initiation of septation processes occurs at an early stage of cell cycle.
Regulation of hydrolase formation and phosphate release in turimycin fermentations
Authors: Müller P. J. , Ozegowski J. H. , Bocker H.
Published: July 2010

During the turimycin fermentation hydrolytic enzymes are excreted responsible for orthophosphate release from phosphate‐containing dissolved and undissolved complex medium constituents. Following a phosphate‐limited growth period the phosphate release leads to a second growth period (diauxic growth). Depending on the rate of phosphate release the length of the lag phase of diauxic growth changes in different fermentations.

The resulting second growth period is correlated with a transient delay in the formation of turimycin, of phosphatases and of nucleases.

The amylolytic activities are formed already within the first hours after the beginning of fermentations. Phosphatases, nucleases and protease are excreted parallel to turimycin formation after extracellular phosphate limitation in presence of ammonia and glucose. A special role of phosphate limitation initiating enzyme synthesis is proposed.
Cellulolytic enzymes associated with the fruit rots of Citrus sinensis caused by Aspergillus aculeatus and Botryodiplodia theobromae
Authors: Adisa V. A. , Fajola A. O.
Published: July 2010

Botryodiplodia theobromae and Aspergillus aculeatus were inoculated in carboxymethylcellulose (CMC) medium and on filter papers. Hydrolysis of the CMC medium and degradation of the filter papers were observed, indicating the production of C1 and Cx cellulases by the two rot pathogens. The C1 and Cx enzymes were also detected in filtrates of rotted orange fruits obtained by infection with the two pathogens.

The cellulases could not induce rot development on their own. However, when they were added to pectinases in an enzyme inoculum, the incubation period for inducing rot development was shorter, thus establishing a secondary role for the cellulases in the rot development. Optimum conditions for the action of the cellulases included a neutral pH and temperature ranging from 25 to 30 °C.
Biologische Wirkungen von Koordinationsverbindungen der Übergangsmetalle β‐Lactamasen‐inhibitorische Wirksamkeit von Cis‐Platin, 2‐Aminopyridin‐palladium‐chlorid, Clavulansäure und Penicillansäure‐Sulfon CP 45 899 im Nitrocefin‐Test und TITERTEK/Microtiter‐Automatensystem
Authors: Fleck W. F. , Heyn B. , Schröer H.‐P.
Published: July 2010

The β‐lactamase‐inhibiting activity of 6m‐ethyl‐pyrid‐2‐yl‐ammine palladium‐dichloride (Pd 25 681) and cis‐dichloro‐diammine‐platinum (II) was studied and compared with the enzyme inhibitory action of potassium clavulanate and the penicillanic acid sulfone CP 45899. Using the nitrocefin test method and the TITERTEK/Microtiter equipment CP 45 899 and potassium clavulanate were the strongest inhibitors of the Bacillus cereus β‐lactamase. Cis‐dichloro‐diammine‐platinum(II) was fourfold less active than the palladium complex Pd 25 681 in äquimolar concentration. The following ID50 values were found: CP 45 899: 0.0281 μg; K‐clavulanate: 0.1274 μg; Pd 25 681: 3.8603 μg; cis‐dichlorodiammine‐platinum(II): 12.5120 μg/100 μl.
Sekundärmetabolite als endogene Effektoren der mikrobiellen Cytodifferenzierung
Authors: Gräfe U.
Published: July 2010

The present survey covers the regulatory role of microbial secondary metabolites and related compounds as endogenous signals of cell differentiation of the producing organisms. Several antibiotics have been shown to exert autoregulatory effects on differentiation‐associated functions. The mechanisms of self‐protection of the producing cells against the autotoxicity of secondary metabolites are discussed in terms of an integral part of the modulation of signal strength. As a further topic, the review deals with the hormone‐like interference of particular metabolites with differentiating cells. Conclusive discussion concerns the potential use of microbial signal molecules either as tools for directed manipulations of product syntheses or as pharmaceutics.
Replikation und Expression des Plasmids pBR 322 während diskontinuierlicher Kultivierung eines stringent und relaxed kontrollierten Stammes von Escherichia coli
Authors: Hecker M. , Wiehle W. , Schroeeter A. , Mach F.
Published: July 2010

The E. coli strains CP78 and CP79 carrying the plasmid pBR 322 display similar growth kinetics in discontinuous culture. During limitation of amino acids the stringent strain CP78 is able to synthesize guanosine‐5′ diphosphate‐3′‐diphosphate (ppGpp) and guanosine‐5′‐triphosphate‐3′diphosphate, but the relaxed strain can not produce highly phosphorylated guanosine nucleotides. During the logarithmic phase of growth both strains contain similar amounts of plasmid DNA. During amino acid starvation plasmid DNA is amplified in the relaxed strain only, whereas in the stringent strain the plasmid content per cell remains constant.

In stationary phase cells of CP78 a higher activity of plasmid‐coded β‐lactamase than in CP79 cells was detected. Furthermore, remarkable differences between both strains were observed in the composition of proteins derived from the periplasmic fraction and separated by polyacrylamide gel electrophoresis.

Our results might indicate a negative control of pBR 322 DNA replication by ppGpp during amino acid starvation.
Wirkung supraoptimaler Temperaturen auf Wachstum und Entwicklung einer Brennereihefe II. Wachstum und Entwicklung der Hefe Saccharomyces cerevisiae, Stamm 193, bei kontinuierlicher Kultivierung im pH‐stat
Authors: Mavrina L. , Pozmogova I. , Rabotnova I. , Schade W.
Published: July 2010

Long term influence of a submaximal temperature (39.5 °C) on a continuous culture of Saccharomyces cerevisiae in a pH‐stat resulted in a reduction of its growth rate from 0.3 h−1 to 0.04 h−1. In consequence of an altered anabolism of the yeast cells a strong and irreversible decrease of the contents of intracellular polymers (DNA, RNA and protein) was stated. Additional changes in the energy metabolism, e.g., the activation of anaerobic pathways of substrate utilization were reversible. A yeast with new physiological features was the results.

At short term action of submaximal temperatures during the time of one cell generation only minor changes in the anabolism were found and a fast return of the culture to normal parameters of growth and development was possible.
Microbiological implications of electric field effects VII. Stimulation of plasmid transformation of Bacillus cereus protoplasts by electric field pulses
Authors: Shivarova N. , Förster W. , Jacob H.‐E. , Grigorova R.
Published: July 2010

The aim of this study was to check the action of electric field pulses (1) on the survival of intact cells and protoplasts of Bacillus cereus and (2) on the transformation frequency of these protoplasts with plasmid DNA from Bacillus thuringiensis transformants. – B. cereus cells and protoplasts are very resistant to high electric field pulses in the microsecond range. The transformation frequency of B. cereus protoplasts with plasmids from B. thuringiensis (pUB 110) can be increased by about one order of magnitude with the electric field pulse technique. The transformants are stable and pUB 110 is preserved as an extrachromosomal element.
Influence of tryptophan and related compounds on ergot alkaloid formation in Claviceps purpurea (Fr.) Tul.
Authors: Erge D. , Schumann B. , Gröger D.
Published: July 2010

L‐Tryptophan did not exert any influence on peptide alkaloid formation in an ergotamine and in an ergosine‐accumulating C. purpurea strain. A different picture was observed in a series of related C. purpurea strains. Tryptophan showed a slight stimulatory effect on the ergotoxine producer Pepty 695/S. A blocked mutant of it, designated as Pepty 695/ch which was able to accumulate secoclavines gave similar results. In a high‐yielding elymoclavine strain Pepty 695/e, the progeny of the former one, tryptophan up to a concentration of 25 mm stimulated remarkably clavine biosynthesis. Furthermore, tryptophan could overcome the block of synthesis by inorganic phosphate. Increased specific activities of chanoclavine cyclase but not DMAT synthetase were observed in cultures of strain Pepty 695/e supplemented with tryptophan. 5‐Methyltryptophan and bioisosteres of tryptophan were ineffective in alkaloid stimulation. These results are compared with those obtained with the grass ergot strain SD 58 and discussed with the relation to other induction phenomena.
Formation, growth and regeneration of incomplete cell wall in spheroplasts of the blue‐green alga Anacystis nidulans in liquid media
Authors: Gabriel M.
Published: July 2010

Growing cells of blue‐green alga, Anacystis nidulans, were treated with lysozyme in osmotically stabilized nutrient medium. Their development and regeneration ability was studied in liquid media. During 5–8 hrs about 95% of cells were converted to osmotically sensitive spheroplasts having a residual wall layer on their surface. The highest viability of spheroplast population was achieved using egg‐white lysozyme for spheroplast preparation and gradual dilution by nutrient medium instead of centrifugation for lysozyme removal. Most of such prepared spheroplasts survived for 3 days of cultivation in nutrient medium, and started to die gradually from 3 to 10 days. Spheroplasts were growing spherically, about 30% of them were growing for 8 days up to 40‐fold increase in volume. Multiplication of thylakoid cisternae in growing spheroplasts was proved by freezeetching. Electron microscopy further revealed newly synthesized amorphous walls of isodiametrical appearance by growing spheroplasts resembling the original cell walls of cells. In liquid media blue‐green alga spheroplasts of Anacystis nidulans can grow for a number of days, however, only regeneration of incomplete wall occur unable to promote reversion of spheroplasts to cells.
Verbreitung methanotropher Bakterien
Authors: Heyer J. , Malashenko Yu. , Berger U. , Budkova E.
Published: July 2010

This paper reports on the investigations of the distribution of the methanotrophic bacteria in various environments and geographic zones. In the most of about 1000 samples investigated by us obligately methanotrophic bacteria were found. More than 300 pure cultures were isolated, among them strains of all five groups of methanotrophs described by Whittenbury et al. (1970). There were great differences in their distribution patterns in several habitats. The occurrence of methanotrophic bacteria even in acidophilic peat bog lakes and in salt‐lakes shows the great ecological amplitude of this group of organisms.

Experiences with the use and the interpretation of the MPN‐method for the enumeration of methanotrophic bacteria are presented. The results of the quantitative investigations enlarge the knowledge about the distribution of these organisms in various natural and artifical habitats and confirm their high frequency in the nature.

The greatest densities of cells are found in sewage, but only small numbers of cells in the open water and sandy sediments of Baltic Sea and in salt‐lakes. Generally the frequency of the methanotrophic bacteria was closely related to the concentration of methane, respectively, to the rate of methane release in the habitat. The high numbers of cells in the aerobic layers of sediments are an indication of the great activity of the aerobic methane oxidation in these zones.
Characterization of carbon nanotube filters and other carbonaceous materials by Raman spectroscopy—II: study on dispersion and disorder parameters
Authors: Heise H. M. , Kuckuk R. , Srivastava A. , Asthana B. P.
Published: July 2010

Recently, we have reported on the characterization of various carbonaceous materials including multiwalled carbon nanotube (MWCNT) filters, which have specific molecular filtering capabilities and good mechanical strength and can be produced in bulk as highly aligned arrays of bundles of CNTs. We have extended our studies using Fourier transform‐Raman spectroscopy with 1064 nm excitation wavelength and a rotating sample holder in the region 1000–2800 cm−1, in addition to 532 and 785 nm, which were used for Raman excitation in our previous study. Raman spectra were analyzed for band positions and line shape with special emphasis on the D‐, G‐ and G′‐ bands. For the single‐walled species, Carbotrap and graphite spectra were also recorded with 488 nm excitation. A dispersion study has been made from the Raman data available with the different excitation wavelengths. Slight band shifts and band broadening could be observed under the two sample conditions, one with the stationary sample and the other with sample rotation. The spectral changes are related to the excessive heating caused in a stationary sample by laser irradiation. Based on our findings in this study combined with our earlier study, we can state that only a careful line shape analysis and study of intensity pattern of the D‐ and G‐Raman bands under well‐defined measurement conditions lends itself as a good measure of degree of alignment in the MWCNT bundles. Copyright © 2010 John Wiley & Sons, Ltd.
Electrospun, Biofunctionalized Fibers as Tailored in vitro Substrates for Keratinocyte Cell Culture
Authors: Grafahrend Dirk , Heffels Karl‐Heinz , Möller Martin , Klee Doris , Groll Jürgen
Published: July 2010

Cell adhesion preventing fiber surfaces were tailored differently with bioactive peptides (a fibronectin fragment (GRGDS), a collagen IV fragment (GEFYFDLRLKGDK) and a combination of both) to provide an artificial extracellular matrix as a substrate for HaCaT keratinocyte cell culture. Therefore, a polymer blend containing a six‐arm star‐shaped statistical copolymer of ethylene oxide and propylene oxide in the ratio 80:20 (NCO‐sP[EO‐co‐PO]) and poly‐[D,L‐(lactide‐co‐glycolide)] (PLGA) was electrospun. The resulting fibers were biofunctionalized and investigated as in vitro substrates using the HaCaT kerationcyte cell line. Appropriate surface chemistry on these electrospun fibers proved to prevent adhesion of keratinocytes, while additional immobilization of certain peptide sequences induced cell adhesion. These specific fibers enable investigation of immobilized active molecules and the subsequent cellular response to the scaffold. HaCaT keratinocytes were found to selectively adhere to those fibers modified with either collagen IV segment GEFYFDLRLKGDK or a mixture of the two peptide sequences GEFYFDLRLKGDK and GRGDS (1:1). However, the synergistic effects of both (the fibronectin fragment and the collagen IV fragment) seem to significantly increase the numbers of adherent keratinocytes.

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Imidazole and Dimethyl Aminopropyl‐Functionalized Hyperbranched Polymers for Nucleic Acid Transfection
Authors: Germershaus Oliver , Pickaert Guillaume , Konrad Juliane , Krüger Ute , Kissel Thomas , Haag Rainer
Published: July 2010

In order to mimic the histidine binding motives of naturally occurring histones as DNA complexing proteins, hyperbranched poly(ethylene imine) and polyglycerol were functionalized with imidazole or 3‐dimethylamino propyl groups. These new polycationic polymers were tested for interaction with dye‐labelled oligonucleotide and DNA using UV and fluorescence spectroscopy and gel electrophoresis. Formation of stable complexes was observed above N/P ratios of 4 for unfunctionalized and 8 for functionalized PEIs. No stable complexes were formed with polyglycerol‐based polyamines up to N/P 16. Cytotoxicity determined by MTT assay of all functionalized PEI polymers was found to be significantly lower than for unfunctionalized PEI. PG‐based polymers showed no toxicity in the tested concentration range. Dynamic light scattering showed that only for PEI21‐Imidaz polyplexes hydrodynamic diameters below 250 nm could be reached.

The influence of functionalization and polymer type on transfection efficiency was evaluated in L929, NIH/3T3 and HeLa cells. Only imidazole‐functionalized PEIs reached similar transfection efficiencies as unfunctionalized PEIs, while 3‐dimethylamino propyl modification resulted in lower transfection efficiencies. We also demonstrated that the polymer plays an important role for transfection properties since, regardless of the modifications of polyglycerol, only low transfection efficiencies were observed at functionalization levels below 50%.

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Multiscale Modeling of Branch Length in Butyl Acrylate Solution Polymerization
Authors: Rawlston Jonathan A. , Schork Francis Joseph , Grover Martha A.
Published: July 2010

Branch lengths resulting from both backbiting and intermolecular chain transfer to polymer are examined for the solution polymerization of butyl acrylate, using a rate‐equation model and ordinary differential equations. Backbiting is allowed to generate branches of varying length, according to a cumulative distribution function obtained from a lattice kinetic Monte Carlo simulation. About 8% of the branches produced by backbiting are 10 mers or longer. In contrast to common assumptions about the origins of short‐chain and long‐chain branches, the model indicates that nearly all of the long‐chain branches may be produced by backbiting, rather than intermolecular chain transfer to polymer.

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Another look at the contingency tables: scores based on Manhattan distances in the phase space
Authors: Stein Joël
Published: July 2010

This alternative presentation of scores is based on the Manhattan distance in the phase space of forecasts. The key factor is represented by the ratio of the weights assigned to misses and false alarms. This ratio is 1 for the Heidke skill score and is equal to the ratio of the number of non‐events to the number of events for the Pierce skill score. A score based on the deterministic limit leads to assign this ratio to either 2 or 0.5 as a function of the base rate. It can also be determined as a function of parameters of a cost‐loss economical model.

Applied to the Finley tornadoes and to two quantitative precipitation forecasts, the geographical representation of the phase space is quite invaluable as it points out the good points and the drawbacks of the forecast. The skill scores deduced from these distances help to summarize the quality of a forecast. Copyright © 2010 Royal Meteorological Society