bluuebunny/crossref_metadata_2025 huggingface dataset:
Carbon‐Fluorine Bondings of Fluorinated Fullerene and Graphite
Authors: Matsuo Yoshiaki , Nakajima Tsuyoshi
Published: January 2005

Carbon‐fluorine bondings of fluorinated fullerenes and fluorine‐graphite intercalation compound CxF were investigated in detail on the basis of XPS data and the potential model using the charge distribution calculated by semiempirical method. It has been confirmed by the present study that two peaks in the C1s spectra observed for fluorinated fullerenes are assigned to carbon atoms bonded to fluorine atoms and those unbound to fluorine atoms, and the small difference in charges and Madelung potentials of fluorine atoms in different circumstances well explains the single peak in F1s spectra of fluorinated fullerenes. In the calculated structures of 1,3‐C60F2 and 1,2‐C60Fx (x = 2−6) used as the models of CxF, three kinds of carbon‐fluorine bondings were observed corresponding to nearly ionic, semicovalent and covalent CF bondings. The calculated result supports that the bi‐intercalation structure of stage 1 CxF consists of nearly ionic and semi‐covalent fluorines.
Neue ein‐ und mehrkernige Komplexe der Lanthanoiden. Zur Reaktion von Ph2Se2 mit Ytterbium
Authors: Geissinger Martin , Magull Jörg
Published: January 2005

überraschende Produktvielfalt bei der Reaktion von Ytterbium mit Dichalkogeniden. In THF bildet sich der einkernige Komplex [Yb(SePh)3(thf)3] 1 (Raumgruppe P31c (Nr. 159), Z = 2, a = 15,353(3) Å, c = 7,8920(10) Å). In dieser Verbindung ist das Zentralion oktaedrisch von den Liganden umgeben. Reaktion in Toluol/THF führt dagegen zu der vierkernigen Ytterbiumverbindung [Yb4(SePh)8O2(thf)6] 2 (Raumgruppe C2/c (Nr. 14), Z = 4, a = 27,084(9) Å, b = 13,021(4) Å, c = 24,002(8) Å, β = 106,13(3)°). In DME erhält man die ionische Komplexverbindung [Yb3(SePh)6(dme)4][Yb(SePh)4(dme)] 3 (Raumgruppe P1 (Nr. 2), Z = 2, a = 11,109(3) Å, b = 11,664(2) Å, c = 36,303(10) Å, α = 84,60(4)°, β = 89,52(3)°, γ = 73,69(2)°). Durch diese Reaktionen sind neutrale und ionisch aufgebaute Ytterbiumkomplexe zugänglich.
über die Reaktionen von CH3OCl, CF3OCl, CF3OF und CF3OH mit dem supersauren System HF/MF5 (M = As, Sb) Darstellung und Charakterisierung von CH3OCl(H)+MF6− und CF3OCl(H)+MF6−
Authors: Minkwitz Rolf , Konikowski Detlef
Published: January 2005

Es wird über die Darstellung der Chloroxoniumsalze CH3OCl(H)+MF6− und CF3OCl(H)+MF6− durch Protonierung von CH3OCl und CF3OCl in dem supersauren System HF/MF5 (M = As, Sb) berichtet. Dagegen lassen sich CF3OF und CF3OH bei gleichen Bedingungen nicht protonieren. CF3OH bildet in supersaurer Lösung die Addukte F2CO · MF5. Die Charakterisierung aller neuen Verbindungen erfolgt NMR‐ und schwingungsspektroskopisch.
Ba2(CN2)(CN)2 und Sr2(CN2)(CN)2 – die ersten gemischten Cyanamid‐cyanide
Authors: Berger Ute , Milius Wolfgang , Schnick Wolfgang
Published: January 2005

Die gemischten Cyanamid‐cyanide M2(CN2(CN)2 (M = Ba, Sr) wurden durch Umsetzung von Ba2N bzw. SrCO3 mit HCN bei 630°C synthetisiert. Die Bestimmung der Kristallstruktur von Ba2(CN2)(CN)2 erfolgte anhand von Röntgen‐Einkristalluntersuchungen bei Raumtemperatur bzw. −100°C, die Struktur des isotypen Sr2(CN2)(CN)2 wurde aus Pulverdaten verfeinert (P63/mmc, Ba2(CN2)(CN)2: a = 1 066,52(5) pm, c = 696,82(3) pm; Sr2(CN2)(CN)2: a = 1 035,91(1) pm, c = 664,23(1) pm; Z = 4). Die Kristallstruktur läßt sich als partiell aufgefüllte Defektvariante des anti‐NiAs‐Typs mit einer verzerrt hexagonal dichten Packung von M2+‐Ionen auffassen. Sämtliche CN22−‐ und ein Viertel der CN−‐Ionen besetzen 3/4 der Oktaederlücken, die restlichen CN−‐Einheiten 3/8 der Tetraederlücken. Im Kristallverband sind die CN−‐Ionen sowohl end‐on als auch side‐on an die Kationen koordiniert. Die Anionen sind schwingungsspektroskopisch unterscheidbar.
The Particulate Air Pollution Controversy
Authors: Phalen Robert F.
Published: December 2004

Scientists, regulators, legislators, and segments of industry and the lay public are attempting to understand and respond to epidemiology findings of associations between measures of modern particulate air pollutants (PM) and adverse health outcomes in urban dwellers. The associations have been interpreted to imply that tens of thousands of Americans are killed annually by small daily increments in PM. These epidemiology studies and their interpretations have been challenged, although it is accepted that high concentrations of air pollutants have claimed many lives in the past. Although reproducible and statistically significant, the relative risks associated with modern PM are very small and confounded by many factors. Neither toxicology studies nor human clinical investigations have identified the components and/or characteristics of PM that might be causing the health-effect associations. Currently, a massive worldwide research effort is under way in an attempt to identify whom might be harmed and by what substances and mechanisms. Finding the answers is important, because control measures have the potential not only to be costly but also to limit the availability of goods and services that are important to public health.
TWO-PHOTON ABSORPTION AND FLUORESCENCE WITH QUADRUPOLAR AND BRANCHED CHROMOPHORES—EFFECT OF STRUCTURE AND BRANCHING
Authors: PORRÈS LAURENT , MONGIN OLIVIER , KATAN CLAUDINE , CHARLOT MARINA , BHATTHULA BHARATH KUMAR GOUD , JOUIKOV VIATCHESLAV , PONS THOMAS , MERTZ JEROME , BLANCHARD-DESCE MIREILLE
Published: December 2004

The photophysical and two-photon absorption (TPA) properties of three homologous quadrupolar and one related three-branched chromophores were investigated. Design of the quadrupoles is based on the symmetrical functionalization of a biphenyl core. Modulation of the nonlinear absorptivity/transparency/photostability trade-off can be achieved by playing with the twist angle of the core and on the spacers (phenylene-vinylene versus phenylene-ethynylene). The quadrupolar chromophores combine high TPA cross-sections, high fluorescence quantum yield and solvent sensitive photoluminescence properties. The branched structure exhibits spectrally broadened TPA in the NIR region (up to 3660 GM at 740 nm measured in the femtosecond regime) but reduced sensitivity to the environment.
EXCITATION WAVELENGTH DEPENDENCE OF LASER ABLATION MECHANISM OF URETHANE–UREA COPOLYMER FILM STUDIED BY NANOSECOND TIME-RESOLVED INTERFEROMETRY
Authors: TADA TAKUJI , ASAHI TSUYOSHI , TSUCHIMORI MASAAKI , WATANABE OSAMU , MASUHARA HIROSHI
Published: December 2004

Etching dynamics of urethane–urea copolymer film was investigated by utilizing nanosecond time-resolved interferometry and tuning excitation wavelength. From the behavior of fringe pattern deformation at the irradiated areas, it is considered that irradiated polymer film was decomposed more effectively with decrease in excitation wavelength. Excitation wavelength dependence of etching dynamics of urethane–urea copolymer film was not well interpreted in terms of total energy density which was stored within the polymer film due to laser irradiation, while photochemical and photothermal processes can explain mostly the results of shorter wavelength (≤ 475 nm) and longer wavelength (≥ 530 nm) excitations, respectively.
Alexithymia in Young Adulthood: A Risk Factor for Pathological Gambling
Authors: Parker James D.A. , Wood Laura M. , Bond Barbara J. , Shaughnessy Peggy
Published: December 2004

Background: Pathological gambling is more prevalent among postsecondary students than among the general adult population. While the prevalence of pathological gambling in this group has risen over the past decade, factors underlying the development of problem gambling among university students remain largely unexplored. One early study found alexithymia to be associated with pathological gambling. The aim of the present study was to further examine the relationship between alexithymia and gambling among postsecondary students. Methods: The relationship between alexithymia and pathological gambling was examined in 562 postsecondary students who completed the South Oaks Gambling Screen (SOGS) and the 20-item Toronto Alexithymia Scale (TAS-20). Results: Approximately 12% of the sample was classified as alexithymic according to the TAS-20. These individuals were found to have significantly more gambling problems, as measured by the SOGS, than nonalexithymic individuals. Approximately 9% of the sample was classified as pathological gamblers according to the SOGS. These individuals were found to have significantly higher levels of alexithymia, as measured by the TAS-20, than nonproblem gamblers. Conclusions: Alexithymia is associated with pathological gambling and may be a risk factor among postsecondary students for developing severe gambling problems.
Somatotopic Organization of the Trigeminal Ganglion Cells in a Cichlid Fish, Oreochromis (Tilapia) niloticus
Authors: Kerem Gulnisa , Yoshimoto Masami , Yamamoto Naoyuki , Yang Chun-Ying , Xue Hao-Gang , Ito Hironobu
Published: December 2004

Somatotopic organization of the trigeminal ganglion is known in some vertebrates. The precise pattern of somatotopy, however, seems to vary in different vertebrate groups. Furthermore, the somatotopic organization remains to be studied in teleosts. From an evolutionary point of view, the morphology and somatotopic organization of the trigeminal ganglion of a percomorph teleost, Tilapia, were investigated by means of the tract-tracing method using biocytin and three-dimensional reconstruction models with a computer. The trigeminal ganglion was one cell aggregate elongated in the dorsoventral direction, which was separate from the facial and anterior lateral line ganglia. Biocytin applications to the trigeminal nerve root labeled ordinary ganglion cells in the trigeminal ganglion and a few displaced trigeminal ganglion cells in the facial ganglion. Biocytin applications to three primary branches (the ophthalmic, maxillary, and mandibular nerves) revealed that trigeminal ganglion cells were somatotopically distributed in the ganglion reflecting the dorsoventral order of the three branches. Ganglion cells of the ophthalmic nerve were distributed in the dorsal part of the trigeminal ganglion, those of the mandibular nerve in the ventral part, and those of the maxillary nerve in the intermediate part. Some of maxillary and mandibular ganglion cells appear to overlap in their boundary region, whereas ophthalmic ganglion cells did not intermingle with ganglion cells of other branches. Labeled-primary fibers terminated in the sensory trigeminal nucleus, descending trigeminal nucleus, medial funicular nucleus, a ventral part of the facial lobe, reticular formation, and trigeminal motor nucleus. Labeled cells were observed in the mesencephalic trigeminal nucleus and the trigeminal motor nucleus. The results suggest that the morphology and somatotopic organization of the trigeminal ganglion of tilapia are similar to those of mammals, except that the axis of the somatotopic organization of the ganglion in mammals is a mediolateral direction reflecting the mediolateral order of the ophthalmic, maxillary, and mandibular nerves.
Wild-Type p53 Overexpression and Its Correlation With MDM2 and p14ARF Alterations: An Alternative Pathway to Non–Small-Cell Lung Cancer
Authors: Wang Yu-Chien , Lin Ruo-Kai , Tan Yi-Hung , Chen Jung-Ta , Chen Chih-Yi , Wang Yi-Ching
Published: December 2004

Purpose

We found a relatively reduced frequency of p53 mutation with a much greater frequency of p53 protein overexpression, which reflected stabilization of p53 protein in the absence of p53 gene mutation. Therefore, we investigated the possibility of alternative mechanisms leading to p53 protein stabilization.

Patients and Methods

We performed gene and protein alteration studies on p53 and its upstream effectors, MDM2 and p14ARF, in tumors from 94 non–small-cell lung cancer (NSCLC) patients.

Results

Immunohistochemical and sequencing analyses indicated that 37 tumors showed overexpression of wild-type p53. An absence of nuclear staining of MDM2 protein was found in 95% of these tumors (35 of 37; P < .001). The tumors with negative MDM2 staining showed a significantly high concordance of loss of Akt activity and low MDM2 mRNA expression (P < .001). Sequencing analysis revealed five distinct MDM2 splicing variants disrupting the conserved p53 binding domain. Corresponding variant proteins were detected in three lung cancer cell lines using the Western blot analysis. Our results also indicated that among the tumors with overexpression of the wild-type p53, 92% (34 of 37) showed immunoreactivity to p14ARF (P = .001). In addition, the deregulation of p53 and MDM2 genes was significantly associated with squamous lung cancer (P < .05) and was correlated with advanced stages (P < .05) and poor prognosis (P < .05).

Conclusion

Our data suggest that immunopositivity of p14ARF together with a low expression of MDM2 contributes to accumulation of the wild-type p53, and that deregulation of the p53-MDM2-p14ARF pathway is important in the pathogenesis and outcome of a subset of NSCLC.
The Emulsifying and De‐emulsifying Properties of Some Microbial Polysaccharides
Authors: Cooper D. G. , Zajic J. E. , Wood J. M.
Published: December 2004

Zahlreiche mikrobielle Polysaccharide sind auf ihre Fäahigkeiten untersucht worden, Wasser‐ und ÖI‐Emulsionen zu brechen oder aber zu stabilisieren.

Negativ geladene schwach verzweigte o‐Phosphonomannane mit einem relativ hohem Phosphorgehalt zeigen gute de‐emulgierende Eigenschaften.

Mannane stellen schlechte De‐Emulgatoren dar, aber einige andere neutrale Polysaccharide erreichen fast so gute Werte wie die besten o‐Phosphonomannane.

Die untersuchten Polysaccharide können nicht als effektive Emulgatoren bezeichnet werden.
A study of water‐air oxygen equilibrium for the analysis of deep tank aeration
Authors: Miháltz P. , Holló J.
Published: December 2004

Die Quellen der zur Berechung des Sauerstofftransfers herangezogenen Gleichgewichtsdaten des gelösten Sauerstoffs werden kritisch gesichtet und die Grenzen der Verwendbarkeit dieser Daten angegeben. Ein bisher nicht beschriebener Zusammenhang zwischen Temperatur, Gesamtdruck und Sauerstoffpartialdruck wird abgeleitet. Die Triebkraft‐Bedingungen der in der biologischen Abwasserreinigung immer breitere Anwendung findenden Tieftank‐Belüftung werden graphisch dargestellt, wobei die Zweckmäßigkeit der Anwendung der logarithmischen mittleren Triebkraft aufgezeigt wird. Für stationäre aerobe Systeme wird eine auf den folgenden Erwägungen basierende Methode zur Bestimmung von kLα beschrieben.
Das Autoselect‐System – ein Automatensystem zur Selektion von Antibiotikaproduzenten. III. Ein Impfautomat zum Isolieren von Einzelkolonien
Authors: Schicht G. , Bradler G. , Steininger H. , Knöll H.
Published: December 2004

An inoculator enabling the isolation of colonies from petridishes onto agar‐filled microcultur cups, arranged in a pattern of 8 × 8 in cassettes, is described. The transfer of the colonies takes place by turning of an inoculation cross with 4 loops. While the cross stops and lowers, one loop is sterilized, another, which has been sterilized shortly before, is being cooled in sterile water, the next one is taking off some material from a colony and the last is spreading the material on the agar of a cup. The capacity of the machine accounts about 600 colonies per hour.
Bioconversion of lipophilic compounds by immobilized microbial cells in organic solvents
Authors: Fukui S. , Tanaka A.
Published: December 2004

Microbial cells were gel‐entrapped with photo‐crosslinkable resin prepolymers or urethane prepolymers, respectively. The resulting gels have different tailor‐made hydrophobic or hydrophilic character. They were used for successful bioconversion of hydrophobic steroids and terpenoids in watersaturated mixtures of organic solvents. The experiments show the influence of the hydrophobicity of the gels and the polarity of the solvent mixtures, respectively. Use of hydrophobic gels and less polar solvents is preferable for bioconversion of hydrophobic compounds. The selective formation of a desired product among diverse products from a single substrate by appropriate use of hydrophobic or hydrophilic gels is possible. In each case, tests should be made to select the appropriate gel and solvent mixture. Bioconversions tested are: dehydroepiandrosterone to 4‐androstene‐3,17‐dione; cholesterol to cholestenone; β‐sitosterol to β‐sitostenone; stigmasterol to stigmastenone; pregnenolone to progesterone; testosterone to Δ1‐dehydrotestosterone or 4‐androstene‐3,17‐dione, respectively; all with immobilized cells of Nocardia rhodocrous; and stereoselective hydrolysis of dl‐menthyl‐succinate to yield l‐menthol with immobilized cells of Rhodotorula minuta var. texensis.
Bioconversion of cellulose wastes to protein and sugar
Authors: Srinivasan V. R. , Miller T. F.
Published: December 2004

A schematic representation of the variety of products which can be obtained by microbial conversion of cellulose is presented.

Alkaline pre‐treatment has been used after milling in all the experiments. Solka‐floc or sugarcane bagasse was used as sources of cellulose. A cellulolytic strain of Aspergillus terreus (ATCC 30514) was cultivated in batch‐, fed batch and continuous culture up to 7 liter stirred tank fermenter. The general growth characteristics were determined by growing on glucose. Results of experiments on the growth of A. terreus for production of biomass on Solka‐floc or Sugarcane bagasse are given, also the ability of crude cellulases to produce sugar syrups by enzymatic hydrolysis of cellulose has been evaluated.
Regulation der mikrobiellen Alkanoxidation mit Hinblick auf die Produktbildung
Authors: Rehm H. J. , Reiff I.
Published: December 2004

Catabolic pathways of long‐chain n‐alkanes in the range of C8 to C18 are demonstrated and results of investigation about the regulation of monoterminal oxidation are given:

– Enzymes of monoterminal alkane oxidation usually are inducible

– Several intermediates of alkane oxidation can inhibit the primary oxidation of concerned alkane

–Substances, e.g. glucose and glycerol, which ordinary don't be developed in catabolic alkane reactions, in many cases have an inhibitory effect on alkane oxidation

The regulation of catabolic pathways has a great influence on the formation of specific products This influence is demonstrated examplarily at the production of biotin, fatty acids and citric acid.
RNA removal from Candida utilis by chemical and thermal treatments
Authors: Otero M. A. , Bueno G. , Conde J. , Gonzáles A.
Published: December 2004

The removal of the content of nucleic acids of fodder yeast (Candida utilis) by treatment with HCl or heat shock was investigated

Acid concentrations between 5 and 15% (on dried matter basis) were used. A maximal removal of the content of nucleic acids of 88% was realized wheńn was worked with 15% HCl, 90 °C during 30 minutes. But under this conditions were observed high demanges of protein and also of some essential amino acids

Good results for diminishing the content of nucleic acids were reached with the highest concentration of acid and a treatment during 20 minutes

The experiments with heat shock were carried out at 68 °C, different times for heating and different contents of yeast

In this way better results than for treatment with acid according to diminishing the content of nucleic acids and yield of protein and essential amino acids were reached

A removal of over 80% of the content of nucleic acids was achieved in all cases.
Gewinnung und Charakterisierung von Prolidase aus Escherichia coli B, II. Charakterisierung, Reinigung und Trägerfixierung des Enzyms
Authors: Ruttloff H. , Friese E. , Lasch J. , Koelsch R.
Published: December 2004

Prolidase, a specific exopeptidase, is isolated from Escherichia coli B. The enzyme being present in the raw extract is purified and enriched by fractionated ammonium sulfate precipitation, ion exchange chromatography on DEAE‐Sephadex A 50 as well as by gel filtration on Sepharose 4 B. Total yield of prolidase amounts to 19% with a 67fold enrichment

Substrate specifity of the enzyme mainly corresponds to that of the animal prolidase. It is able to hydrolize the imido linkage at the N‐terminal end of prolin in the case of di‐ and tripeptides. The temperature optimum of prolidase from E. coli B is 37 °C, the pH‐optimum from pH 7.6 to 9.0. Storage stability at pH 8.6 and a temperature of 4 °C is optimal. The enzyme is only active in presence of Mn2+‐ions. This metal cannot be replaced by Mg2‐‐ or Zn2+‐ions

A high enzyme activity and storage stability in presence of Mn2+‐ions can be reached by immobilization of the prolidase, by covalent binding on Sepharose 6 B, adsorption on DEAE‐Sephadex as well as by combination with glutar dialdehyde on DEAE‐Sephadex.
Modeling step function responses in continuous fermentation processes
Authors: Simion F. A. , Wei Chia‐Jenn , Tanner R. D. , Crooke P. S.
Published: December 2004

Understanding both the qualitative and quantitative transient responses to inlet flow and substrate step functions has been a relatively unsolved problem for continuous fermentation processes. This study of transient responses and simple descriptive models suggests that the saturation constant of the MONOD equation is a variable. Thatf variable depends on the rate constants of parallel biochemical pathways leading to cell growth, the concentration of cells themselves, and the concentration of all products in the culture. Mechanisms for describing the hysteresis behavior of the growth rate funcion are postulated in terms of the underlying molecular biology of the microbial system.
Rechnergestützte führung von fermentationsprozessen Teil I
Authors: Prause M. , Schulz H.‐J , Wagler D.
Published: December 2004

The industrial continuous fermentation for the production of microbial protein is like any real process subject to disturbances. The considerable social expenditures involved in production make it necessary to restrict the negative consequences of these disturbances to a minimum by means of suitable measures. One such measure is the computer‐aided adaptation of the static optimum. For the reaction on nonmeasurable disturbing inputs an algorithm is given containing the steps data filtering, adaption of process model and optimization, and the solution of the data‐filtering problem in the widest sense by spline functions is discussed. The application of this algorithm to a specific problem of process control is demonstrated in [1].
Biotin vitamers content of lactose and beet molasses
Authors: Szopa J. S.
Published: December 2004

The biotin activity of beet and lactose molasses against the test strain Saccharomyces cerevisiae 225 by auxanographic method was evaluated. The level of lactose molasses biotin activity is almost twice as high as that obtained in the case of beet molasses. The results of bioautography with test strains Saccharomyces cerevisiae 225 and Lactobacillus arabinosus 17‐5 indicate the qualitative composition of biotin derivatives (vitamers) in both molasses. Depending on the various technological steps e.g. sterilization or clarification one may find differences in the content and qualitative composition of biotin vitamers.
Die Bedeutung des Erhaltungsstoffwechsels und der „maximalen”︁ Ausbeute
Authors: Koné S. , Behrens U.
Published: December 2004

This paper examines the microbial denitrification of a medium containing acetate as C‐source and of an industrial effluent containing volatile fatty acids as main components a ndphenolics as minor components.

Values for m and Ymax are represented. It has been concluded that the maintenance coefficient comprises also those processes not involved in the maintenance metabolism of the cells.

The least fraction of the rate of substrate utilization of this extended maintenance metabolism has been expressed by m · 100/qmax. From the values of Ymax a P/2e‐ratio < 1 and the equation of cell synthesis have been evaluated.
Heat flow measurements in aerobic microbial growth processes with a nonisothermal calorimeter operating directly in the fermenter
Authors: Heinritz B. , Stoll P. , Glombitza F.
Published: December 2004

A nonisothermal flow calorimeter operating directly in the fermenter was used for heat flow measurements of aerobic microbial growth processes with high biomass productivities. The measuring arrangement makes it possible to describe transitional stages of aerobic yeast cell growth by the ratio of heat production to oxygen consumption (oxy‐caloric coefficient). The oxy‐caloric coefficient was not constant under the described conditions. The results refer to the existence of an additional energy‐delivering mechanism in microbial systems with aerobic carbon source utilization. The mechanism can involve polyphosphate bond division coupled to biomass synthesis.
The genus thiobacillus: Physiology and industrial applications
Authors: Martínez J. P. , Garay E. , Alcaide E. , Hernández E.
Published: December 2004

This review deals with different aspects concerning the genus Thiobacillus as an obligat chemoautotroph able to oxidize reduced anorganic sulphur compounds. There are given the following topics: physiology of the genus (nutritional requirements, enzymatic complexes for sulphur oxidation, energy generation, reductive CO2 assimilation and growing in presence of organic compounds).

The ecological significance of Thiobacilli in the sulphur cycle in Nature is presented. The industrial applications of Thiobacilli in respect to the leaching processes that allow the recovery of metals through oxidation and solubilization from low‐grade ores are discussed, with special reference to copper and uranium. A critical revision is done of acid mine drainage impact on the environment, and the use of adequate countermeasures is stressed.
Zur Kinetik der Mischsubstratutilisation bei der Citronensäure‐akkumulation durch Saccharomycopsis lipolytica EH 59
Authors: Iske U. , Gwenner Ch. , Bullmann M. , Uhlenhut G.‐J. , Schindler G.
Published: December 2004

The mechanism and the kinetic of the assimilation of mixed substrates during the organism growth and the product excretion by strain of Saccharomycopsis lipolytica have been studied. The assimilation of citric acid for the organism growth was prevented when glucose and/or n‐paraffins are present as substrates. Citric acid concentrations higher than 30 g/l in the fermentation medium decrease the growth rate on the substrate glucose. Kinetic studies of the mixed substrate assimilation by means of a n‐tetradecane‐1‐C‐labelled paraffin fraction proved that in discontinuous as well as in continuous 1‐stage‐processes for microbial production of citric acid glucose as substrate is only used for the organism growth whereas the n‐paraffin fraction is only used for the acid excretion.
Enzymatische Hydrolyse und Ethanolgärung von Lignocellulosen
Authors: Danielová E. , Farkaš V. , Bauer Š
Published: December 2004

The kinetics of enzymatic hydrolysis of different lignocellulosic materials (wheat straw, newspaper and microcrystalline cellulose Avicel PH 101) was studied using the cellulase complexes from Trichoderma reesei QM 9414 and its mutants M 5, M 6, MHC 15 and MHC 22. The maximum yields of hydrolysis were obtained with wheat straw partially delignified with 1% NaOH as substrate, and using the enzyme from the mutants T. reesei M 6 and MHC 22. The possibility of simultaneous enzymatic hydrolysis and ethanol fermentation of wheat straw using the enzyme complex from M 6 and yeasts of the genus Candida and Torulopsis was also investigated. A good conversion of liberated glucose and cellobiose to ethanol was obtained, however, xylose was not fermented.
Biochemische und mikrobiologische Aspekte der „Nuoc‐mam”︁‐ Industrie in Vietnam
Authors: Phai Le Dinh
Published: December 2004

Nuoc‐mam is a traditional foodstuff of the people of Vietnam. It is an aromatic sauce of a pleasant taste and consists of a fish hydrolysate. The hitherto used method for producing Nuoc‐mam is on principle an autolysis of fish in combination with a microbial fermentation and leads to a salt containing solution of amino acids and of products from removed conversion‐ and synthese‐ products from fish and microorganisms.
SCP‐Produktion auf der Basis von Kohlenwasserstoffen
Authors: Ringpfeil M.
Published: December 2004

Microbial synthesis of SCP on hydrocarbons is regaining importance. Improved methods of energetic balancing allow its economic assessment also under conditions denying direct proportionality between costs and social expenditures. Main methods for augmenting economy of SCP synthesis are recovery of further products beyond SCP, simplification of downstream processes, and rise in yield and productivity of fermentation.
Enzymology of alkane degradation in pseudomonas aeruginosa
Authors: Vandecasteele J. P. , Blanchet D. , Tassin J. P. , Bonamy A. M. , Guerrillot L.
Published: December 2004

A study of alkane degradation in Pseudomonas aeruginosa has been carried out over the last twelve years in the author's laboratory. This study has been aimed at the detailed characterization of the enzymes involved in alkane oxidation to fatty acids, alkane hydroxylase, alcohol dehydrogenase and aldehyde dehydrogenase. Here are summarized the main results of this study and described with some more detail the points which have not yet been reported. Some general conclusions which can be drawn from the evidence obtained are presented.
Untersuchungen zur Anreicherung von Ubichinon‐9 aus Lipid‐Kohlenwasserstoff‐Franktionen mittels Sepahdex LH‐20
Authors: Voigt B. , Reutgen H. , Worbs M. , Sesser I.
Published: December 2004

Sephadex LH‐20 was tested for a potential application in the enrichment of ubiquinone‐9 from a lipid‐hydrocarbon‐extract. The lipid‐hydrocarbon‐extract was isolated from yeast grown on gas oil (b. p. 240 to 380°C) as carbon‐source. The main components of the lipid‐hydrocarbon extract were phosphatides, glycerides, fatty acids, and hydrocarbons of gas oil. By use of Sephadex LH‐20 and CHCl3/CH3OH (2:1)as eluent it is possible to concentrate the whole ubiquinone‐9 in a special fraction both directly from the lipid‐hydrocarbon‐extract and from the aceton‐soluble part of the extract

The concentration of ubiquinone in the special fraction was ten times higher than in the raw‐material and the hydrocarbons were separated completely.

Ubiquinone‐9 can be obtained by a simplified separation from the enriched fraction.
Fuel alcohol production by Zymomanas anaerobia: Kinetics
Authors: Kosaric N. , Ong S. L. , Duvnjak Z. , Moser A.
Published: December 2004

Process kinetics of a strain of Zymomonas anaerobia,which recently was shown to posses a high potential for ethanol production,are described applying the formal macroapproach

The effect of ethanol inhibition on microbial growth,substrate utilization and alcohol production was investigated in detail. Growth rate and yield coefficients were affected by the ethanol concentration

Several mathematical model functions from literature were tested for the quantification of experimental batch data. As none of these models was able to describe the entire growth phase a modified model using formal kinetics was developed for the rates of growth,substrate utilization and product formation (see Eqs. 10, 14, 18).
Characteristics of genetic material with reference to patent documents
Authors: Knuth S. , Belyakova L. G. , Velkov V. V. , Dementyev V. N. , Lommi H. J. , Harper R. A. L , Gyllenberg H. G.
Published: December 2004

Characteristics of genetic material: plasmids, vectors, recombinant DNA and DNA fragments were, studied from 235 patent documents. These documents were from the patent offices of the Federal, Republic of Germany (38), the German Democratic Republic (15), the European Patent Office (53), Finland (43), Great Britain (65), the Soviet Union (3), and the United States of America (18). Attention was paid also to the terminology used in the patent documents. According to this study the way in which the genetic material was characterized in patent documents of different countries was quite variable, and the terminology used was sometimes confusing.
Cultivation of yeasts on hydrolysate nutrient medium obtained from the production of microcrystalline cellulose
Authors: Sokolov T. , Kostov V. , Velkova R. , Kehlibarova L. , Jelev St. , Tzvetkova B. , Mladenova J. , Loseva L.
Published: December 2004

Studies of the biomass production during a continuous cultivation of yeasts on a nutrient medium, prepared from a hydrolysate from the production of microcrystalline cellulose, have been carried out. A new strain of yeasts has been used. Its cultivation has been achieved without addition of biostimulators to the nutrient medium in spite of their absence in the initial hydrolysate. Practically a complete assimilation of sugars has been achieved at high dilution rates (D = 0.25 to 0.50 h+1). The yield of biomass achieved is above 50% compared to the initial sugars and it contains 48.89% true protein. The results obtained offer the possibility of a complex utilization of the products of cellulose hydrolysis in the production of microcrystalline cellulose with a realization of a waste free technology.
Microbial gas balance measurements: Basic interrelations and error estimation
Authors: Neubert M. , Minkevich I. G.
Published: December 2004

The given paper represents formulae for calculation of oxygen consumption and of carbon dioxide formation in a microbial culture obtained from corrected measuring data of gas balance measurements. Basic relations between these measuring data the respiration quotient RQ were derived. The influence of measuring error to the accuracy of determination of oxygen consumption and of carbon dioxide formation at the analysis of gas concentrations and of air flow is discussed. It is shown that the determination of carbon dioxide formation rate is possible in many cultivation regimes with better accuracy than the determination of oxygen uptake rate.
On Intermediate Products of Induced Autolysis of Intracellular Proteins of the Saccharomyces cerevisiae Yeast (in Russian)
Authors: Babayan T. L. , Latov V. K. , Belikov V. M. , Kalunyanza K. A.
Published: December 2004

It was discovered that in the process of baker's yeast autolysis the accumulation of intermediate peptides takes place. The separation and isolation of autolysate peptide fractions as obtained in various times from the beginning of the process, were accomplished. The qualitative characteristic of molecular‐weight variation of this fractions dependant on the time was also determined. The intermediate peptides were shown to be hydrolysed additionally with the help of their own immobilized proteases.
Methanol‐Assimilation durch ein acidophiles Bacterium der Gattung Acetobacter
Authors: Babel W.
Published: December 2004

Generally, methylotrophic bacteria grow optimally in a pH range between 6 and 7.2. The assimilation of methanol can take place via several pathways. Acetobacter methanolicus preiers an acidic pH range for growth, the pH optimum is about 4, and it uses the FBP variant for methanol assimilation.

The latter is interesting from a regulatory point of view because phosphofructokinase disappears during growth on glucose, which is assimilated via the hexosemonophosphate pathway. Since Entner‐Doudoroff enzymes and phosphoketolase are absent in A. `ethanolicus as well as in non‐methylotrophic Acetobacter and Gluconobacter species phosphofructokinase becomes a key enzyme of the assimilation of methanol.

Although A. methanolicus uses the hexulosephosphate pathway the growth yield on methanol is smaller than with other “hexulosephosphate pathway bacteria” e. g. with obligate methanol assimilating bacteria.

At first sight it may appear that the acidic optimum pH is responsible for the smaller growth yield and the discrepancy between the experimental and predicted values.

The relationship between the dependence on and the protection from, high external proton concentration on the one hand and the causes of the low growth yield on the other are discussed. Accordingly, A. methanolicus and another heterotrophic acidophiles seem to be acidoresistant above all, their machinery guaranteeing the protection from the high proton concentration is responsible for the acidophily and the low growth efficiency is caused by a simple respiratory chain.
Untersuchungen zur Anreicherung von Ergosterol und Ubichinonen aus Lipid‐Kohlenwasserstoff‐Fraktionen
Authors: Vier B. , Voigt B.
Published: December 2004

Adsorption on Silicagel was used for the enrichment of ergosterol and ubiquinone‐9 from a lipid‐hydrocarbon extract. The main components of the lipid‐hydrocarbon extract were hydrocarbons of gas oil (B. p. 513 to 653 K)phosphatides, glycerides, and fatty acids.

By adsorption on silicagel (1 part silicagel to 2–3 parts of lipid‐hydrocarbon extract dissolved in hexane) were ergosterol and ubiquinone‐9 enriched and nearly completely separarated from hydrocarbons and phosphatides, partly from glycerides and fatty acids. Ergosterol and ubiquinone‐9 can be obtained by a simplified separation from the enriched fraction.
Rechnergestützte Führung von Fermentationsprozessen, Teil 4
Authors: Prause M. , Schulz H.‐J. , Wagler D.
Published: December 2004

In parts 1–3 of the publication exceptionally stationary processes were used as information sources. In this fourth part the application of transition states for the adaption of the static model is investigated. A solution on the basis of a simple disturbance model is proposed and an evaluation of this procedure is given.
Zu Problemen der Photosynthesemessungen bei der Kultivierung von Mikroalgen
Authors: Arndt H. , Tschirner E. , Böhm H.
Published: December 2004

The rate of photosynthetic activity of a single alga cell, their variability in the course of individual life, the time dependence of conditional influences, the dependence of the action of the condition on the registered parameter are shown by results of our measurements. The further underline the necessity of parallel short‐ or longtime measurements with several charges. Under these conditions, techniques on the basis of gasanalysers are profitable for the planning of measuring systems for photosynthesis with the ability to continuous, simulataneous in vivo measurements of photosynthetic rates of O2‐output and CO2‐fixation in open gas‐stream with parallel charges. A measuring system, which meets these requirements, is demonstrated.
Der Einfluß der Konzentration von Ethanol und Essigsäure auf den Adenylat‐Pool bei Acetobacter Rancens
Authors: Hitschmann A. , Zucker‐Kerbler D.
Published: December 2004

The influence of ethanol and acetic acid concentration on the ATP‐pool and energy charge of Acetobacter rancens was investigated.

The behaviour of growth and ATP‐pool is contrary one to each other. An increasing concentration of acetic acid results in decreased growth rate, ATP‐pool and energy charge.
Bestimmung des isoelektrisch fällbaren Proteins aufgeschlossener Mikroorganismen mittels Coomassiebrillantblau G‐250
Authors: Pauli G. , Kreuter Th.
Published: December 2004

An analytical method for a rapid determination of the protein dissolved from microorganisms after cell disintegration and protein extraction is presented, thereby distinguishing both the isoelectrical precipitable and the isoelectrical nonprecipitable protein fraction. The method is especially usefull for controlling disintegration and protein extraction steps in production of protein isolates from microbial biomasses.
Der Laborkleinfermentor LF2 – Physikalische Kenndaten, Beurteilung der Originalkonfiguration und Charakterisierung spezieller Ausrüstungsvarianten
Authors: Grosse H. H. , Reichenbach P. , Bocker H.
Published: December 2004

The stirred laboratory scale fermenter LF2 is a powerful device for fermentations with up to 3 liters culture broth [1]. It was designed in the Academy of Sciences of the C.S.S.R. and has found a rather wide application in a great number of organizations working in the fields of biotechnological education, research and industry in the G.D.R. and the C.S.S.R.

The LF2‐fermenter is well suitable for carrying out a broad manifold of aerated biotechnological works without contaminations in basic research and process development.

The mechanic and electronic design gives a lot of room for the realization of special equipment variants like special‐shaped reactor vessels or special electronic moduls for automatic control.
Autohydrolysis extraction process as a pretreatment of lignocelluloses for their enzymatic hydrolysis
Authors: Targoǹsky Z.
Published: December 2004

Autohydrolysis was studied as a pretreatment to enhance sugar yields from enzymatic hydrolysis of wheat and rape straw, beech, birch and poplar sawdust. Reaction temperatures were 185°C to 212°C and the reaction time 20 min. The pretreated slurries were hydrolyzed with “Novo” cellulase and Fusarium sp. 27 cellulase at 45°C and pH 4.8 for 24 h with addition of Fusarium sp. 27 cellbound cellobiase. From 85% to 90% sugar content of substrates were converted to reducing sugars after 24 h enzymatic hydrolysis, with exception of poplar wood.

10.8 g biomass was obtained after cultivation of Fusarium sp. 27 with water solution hemicellulose fraction from 100 g beech sawdust autohydrolyzed at 200°C during 20 min.
Modelling oscillatory behavior in batch fermentations
Authors: Lenbury Y. , Steppan J. J. , Park D.‐H. , Tanner R. D.
Published: December 2004

A batch fermentation is modelled with constant and variable yeild terms. It is shown that the model cannot exhibit oscillations if a constant yield term is used. Oscillations in the cell concentration, but not in the limiting substrate concentration, can be simulated if a variable yield function of the limiting substrate is used. Conditions, for which the variable yield needs to satisfy in order to generate oscillations in the cell concentration, are discussed. The primary condition is that the yield must become zero at the same time that the specific growth rate does. Experimental results exhibiting oscillatory behavior are presented and compared with the proposed model.
Exogenous cellulases of thermophilic micromycetes. Part I. Selection of producers
Authors: G. Kvesitadze , L. Kvachadze , T. Aleksidze , D.K. Chartishvili
Published: December 2004

More than 600 micromycetes – representatives of different genera have been investigated for their ability to produce exogenous cellulases. Most of the investigated cultures were found to produce these enzymes, 24 cultures being thermophilic, and 18 thermotolerant. Cellulase or its derivatives proved to be the most favourable carbon source for cellulase secretion. None of the thermophilic cultures studied manifested the ability of exogenous exoglucanase biosynthesis. Using UV‐rays as mutagen, a mutant strain A. terreus T‐49 has been obtained being characterized by an increased endo‐glucanase and cellobiase activity, as compared to the initial strains. The cellulase preparations of thermophilic micromycetes contain one cellulasic component: endo‐glucanase, or two: endo‐glucanase and cellobiase.
Biotransformations. XIX. Reduction of some terpenic ketones by means of immobilized cells of rhodotorula mucilaginosa
Authors: Mironowicz A. , Siewinski A.
Published: December 2004

Reduction of (−)‐menthone ((−)‐1), (+)‐(R)‐methyl‐α‐campholenone ((+)‐2), (+)‐carvone ((+)‐3), and eucarvone (4) was carried out by means of cells of the Rhodotorula mucilaginosa species immobilized in polyacrylamide gel. Alcohols with the (S)‐configuration, (+)‐neomenthol ((+)‐1a), (+)‐(R)‐methyl‐α‐campholenol ((+)‐2a), (−)‐neoisodihydrocarveol ((−)‐3a), dihydroeucarveol ((−)‐4a), and small amounts of (−)‐dihydroeucarvone ((−)‐5), were obtained. The cells of R. mucilaginosa maintained after this reaction ability to reduce standard acetophenone to (−)‐1‐phenyl‐1‐ethanol.
Xylan‐Containing supports used to separate xylanase from the cellulases of aspergillus terreus F‐413
Authors: Paszczyński A. , Rogalski J. , Szczodrak J. , Dawidowicz A.
Published: December 2004

The separation of xylanase from cellulolytic enzymes of A. terreus F‐413 by affinity chromatography on xylan‐containing supports was investigated. Xylanase purified over tenfold was obtained after column chromatography on xylan bound to controlled porous glass. The molecular weight of the purified enzyme has been found to be 140 000 daltons, and it is homogeneous in polyacrylamide gel electrophoresis. Purified xylanase also showed residual celluloytic activity (perhaps cross‐specificity) with cellulosic substrates.
Herstellung von L‐Lysindecarboxylase aus Klebsiella pneumoniae
Authors: Huber J. , Weisbach F.
Published: December 2004

L‐Lysine decarboxylase (LL‐Lysine carboxylase E.C. 4.1.1.18) is produced by a strain of the genus Klebsiella.

The bacterial cells are cultivated at a temperature of 37°C with and without shaking. The production of LL‐Lysine decarboxylase is increased by adding of LL‐Lysine to the medium. At the end of cultivation the cells are killed by thymol, washed in water and dried by means of acetone and ether.

Compared with specimen derived from other bacteria the LL‐Lysine decarboxylase in the shape of dried cells shows a high specific activity. The preparations are free of disturbing enzyme activities, have a high level of stability and may be used for determining of LL‐Lysine by means of enzyme electrodes.
Assimilation of animal fats by yeasts and synthesis of protein by continuous cultivation in a complex nutrient medium
Authors: Kostov V. , Popov B. , Popova L. , Kehlibarova L. , Borisova I.
Published: December 2004

Under the conditions of continuous cultivation studies were carried out on a mixed culture (association) with two strains of yeasts: Candida sp., assimilating animal fats, and Candida scottii, assimilating reducing sugars. A complex nutrient medium of wood hydrolysate was used.

It was established that in this medium, at a rate of dilution of D = 0.25 h−1, the mixed culture assimilates the fats and the sugars simultaneously. As a result of this the yield of absolutely dry yeasts with regard to the total sum of fats and sugars amounts to 71% in the case of incineration fat and to 82% in the case of technical pork fat.

The contents of protein, amino acids, lipids and ashy substances in the yeasts obtained from a medium with fats do not differ substantially from those obtained from the same medium without fats.
Hybridoma cells produced by electrofusion in a homogeneous electric field
Authors: Abel H. , Stolley P. , Dreyer G. , Walther I. , Junge C.
Published: December 2004

In the customary technique will be used a fusion chamber with an inhomogeneous electric field. The disadvantage is that the fusion conditions are not constant in the chamber. Yet for di‐electrophoretic collection of the cells their own field‐inhomogenizing influence is sufficient that is, the electrofusion can proceed also in very simple chambers with homogeneous fields.
Increase and limits of growth yields for heterotrophic microorganisms
Authors: Babel W.
Published: December 2004

Substrates for heterotrophic growth of microorganisms are more or less energy‐limited.

In order to improve the growth yields phenotypic and genetic measures come into consideration. By means of the auxiliary substrate concept the carbon metabolism determined carbon conversion efficiency of about 75% for C2 compounds (i.e. non‐glycolytic, gluconeogenetic substrates) and about 85%, respectively, for C3 or glycolytic substrates can be attained experimentally.

With methylotrophic microorganisms the growth yield might approach to this limit if the methanol oxidizing methanol dehydrogenase (bacteria) and methanol oxidase (yeasts) are replaced by an NAD+‐linked dehydrogenase.

Due to an increase in the overall P/O quotient up to the maximum this limit cannot be reached.