bluuebunny/crossref_metadata_2025_split huggingface dataset:
Ammonium‐nitrogen metabolism and nitrogen fixation in azotobacter vinelandii
Authors: Shawky B. T. , Ghali Y. , Ahmed F. A. , Kahil T. 
Published: December 2004

AbstractThe probable effect of increasing levels of ammonium nitrogen on the growth, efficiency of nitrogen fixation, and main cellular constituents of Azotobacter vinelandii was studied under shaking and static culture conditions.The presence of NH4+‐N up to 50 mgl‐1 level has no harmful effect on the multiplication as well as the yield efficiency ratio of the tested organism. A. vinelandii was able to fix dinitrogen in the presence of NH4+‐N when both nitrogen sources were available in the culturing medium. The efficiency of nitrogen fixation was affected by the initial presence of NH4+‐N in the medium, it was quite low at the highest level. The crude protein efficiency ratio was correlated inversely with the initial NH4+‐N concentration, whereas the total carbohydrate efficiency ratio as well as the total lipid efficiency ratio were positively correlated with the NH4+‐N concentration. The presence of NH4+‐N in the culturing medium has no essential influence on the qualitative composition of the amino acids in the Azotobacter cells.
Zum zeitlichen Verlauf von Substratkonzentrationsprofilen in einer Enzymträgerkugel
Authors: Carl S. 
Published: December 2004

AbstractIn this paper the time evolution of substrate concentration profiles in spherical particles with homogeneous enzyme distribution is investigated. It turns out that the concentration S  S(x, t) is monotone increasing in the time variable t against the uniquely defined steady state Ŝ  Ŝ(x). Explizit formulas are derived for the estimation of the difference between the steady state Ŝ and the presteady state S, that hold for all t ≧ 0, i.c., it is not only determined the order of magnitude of the convergence for sufficiently large t.
Identifizierung prozeßspezifischer lag‐Zeiten und Berücksichtigung bei der Berechnung phänomenologischer Wachstumsparameter
Authors: Reimann B. , Mund K. 
Published: December 2004

AbstractA significant difference between the maxima of the specific growth rate (μ) and the specific product formation (kp) may indicate a retarded correlation model of biomass (X) and product (P).Therefore phenomenological growth parameters which connect X and P or their derivations (Yp/x, kp) have to take into consideration this kind of lag‐time in the same way.
Solid substrate growth of white rot fungi on coffee pulp
Authors: Rolz C. , De Leon R. , De Arriola M. C. 
Published: December 2004

AbstractThe presence of several antiphysiological factors limit the use of coffee pulp in monogastric and ruminant feeding. Twenty six white rot fungi were grown under solid substrate conditions in previously ensiled and pressed coffee pulp without adding additional sources of nitrogen. All grew and wholly covered the surface of the substrate. Six of them produced fruiting bodies. The weight loss interval ranged between 6.7–28.0% dry matter before fructification and from 17.0 to 48.7% after fructification. Some fungi biodegraded about 70, 55 and 47% of the total polyphenols, caffeine and permanganate lignin present in the original substrate.
Transformation of 7,8‐dihydrocodeinone to 7,8‐dihydroisocodeine by Aureobasidium pullulans
Authors: Fuska J. , Khandlová A. , Proksa B. , Fusková A. 
Published: December 2004

AbstractAureobasidium pullulans reduced stereospecifically 7,8‐dihydrocodeinone to 7,8‐dihydroisocodeine. Activity of the culture was inhibited by some substances present in the malt extract.
Stable ionotropic gel for cell immobilization using high molecular weight pectic acid
Authors: Berger R. , Rühlemann I. 
Published: December 2004

AbstractIt is shown that Ca‐ and Al‐pectate gel beads prepared by use of high molecular weight polygalacturonic acid (viz. polygalacturonic acid having a high STAUDINGER index) are well suited for cell immobilization. The pectate beads are much more insensitive to those ions and chemical agents which destructively act on alginate beads (such as phosphate, citrate, gluconate, lactate as well as a high excess of sodium, potassium, and/or ammonium ions), even without addition of gelling cations to the liquid phase.
Ein neues Verfahren zur zweistufigen Kultivierung von Mikroorganismen. Teil I. Prinzip des Verfahrens
Authors: Teich W. 
Published: December 2004

AbstractThe importance of the two‐step process technology in the field of biotechnological processes is demonstrated. Its application especially is pointed out to waste water treatment. The general advantages of such processes exist in its possibility to use different strains of microorganisms in an effective way and to realize parameters of the technological process in a defined sequence. But with the application of two‐step process techniques (add of biomass to the second step) an extension of retention time is connected with a decrease of yield coefficient. This disadvantage may be eliminated by an inactivation of microorganisms after the first step. The inactivation of microorganisms can be realized by increase of temperature, of pH‐value or by addition of toxic substances. The inactivated microorganisms act as inert particles in the second step not utilizing substrate and oxygen. The new process regime has a lot of advantages, eg. increase of biomass concentration, increase of utilization of complexe substrates and possibility of coupling different biotechnological processes.
Production of cellulases by Trichoderma reesei QM 9414 in batch and fed‐batch cultures on wheat straw
Authors: Acebal C. , Castillon M. P. , Estrada P. , Mata I. , Aguado J. , Romero D. 
Published: December 2004

AbstractTrichoderma reesei QM 9414 was grown in batch fermentation on wheat straw pretreated by different methods as the sole carbon source. Cellulase production was maximal with NaOH treated wheat straw at a concentration of 10 g/l and an initial pH of 5.5. The addition of fresh straw produced an elongation of the exponential phase or the beginning of a new exponential phase when the additions were carried out at 50 and 120 h, respectively. Filter paper and carboxymethylcellulase activities decreased as an answer to the addition of wheat straw and the levels were regained at the end of fermentation. The decreases of activities were accompanied by the increases of soluble sugar levels, which decreased at the end of fermentation. β‐glucosidase activity was stimulated by wheat straw addition at 50 h while not by addition at 120 h; however, at the end of the fermentation the levels of activities were both similar to control. The studies of pH stabilities of these enzymes allow assurance that the effect of the addition of wheat straw on the enzyme activities is not produced by the changes of the pH during the fermentation.
Einfluß von D,L‐Ethionin auf Zellkulturen von Ruta graveolens L
Authors: Hertel S. C. , Gröger D. , Schmauder H.‐P. 
Published: December 2004

AbstractD,L‐Ethionine was added in varying concentrations (0.1–1 mM) to two cell suspension cultures of Ruta graveolens. Growth, alkaloid formation and activities of some shikimate pathway‐specific enzymes in these cultures were estimated. Also the effect of ethionine on shikimate pathwayspecific enzymes under in vitro conditions was followed. Growth is only slightly inhibited in supplemented cultures. Alkaloid formation is drastically reduced in a low‐producing and to a lesser extent in the high producing cell line by ethionine. Activities of DAHP synthase, chorismate mutase, and anthranilate synthase in the presence of ethionine are in different Ruta strains to a varying degree affected.
Kontinuierliche Methanolfermentation mit Hansenula polymorpha MH 26 unter Zusatz von Getreideschlempe und Melasse
Authors: Schneider J. D. , Hadeball W. , Feiler E. 
Published: December 2004

AbstractThe methanol‐utilizing yeast Hansenula polymorpha MH 26 is thermotolerant and grows at 40°C and pH 3.5 with a maximum specific growth rate of 0.23 h−1 on methanol.In continuous cultivation the maximum cell yield can be improved of 0.35 (methanol) to 0.44 g dry cells/g methanol (mixtures of methanol and stillage) through additional utilization of the essential growth and nutritive substances of stillage.The utilization of methanol and sucrose (molasses) at various mixtures is simultaneous possible. Investigations of these mixtures with 14C‐marked methanol show an increasing incorporation of methanol of about 20–30% against methanol alone. This effect is caused by the increasing metabolization of sucrose to carbondioxide and additional energy delivery for better assimilation of methanol.
Streptomyceten als Bildner industriell und diagnostisch bedeutsamer Enzyme
Authors: Hartung B. 
Published: December 2004

AbstractThis review deals with known natural enzyme activities of streptomycetes and their applications. This knowledge may help potential users to exploit these organisms for individual purposes. The data given in tables are based on scientific publications and the IUPAC recommendations regarding nomenclature are followed. Included are only enzymes already utilized, with those of the primary metabolism being neglected.
Characterization of the course of D‐glucitol biotransformation by strains gluconobacter oxydans
Authors: Pelechová J. , Kulhánek M. , Gramanová I. , Krejčí J. , Heřmánková V. , Staněk J. 
Published: December 2004

AbstractProduction strains Gluconobacter oxydans used in manufacture of L‐sorbose from commercial D‐glucitol were evaluated by HPLC determination of D‐glucitol, L‐sorbose, D‐fructose, D‐mannnitol, D‐arabinitol, D‐xylulose, and D‐threo‐2,5‐hexodiulose in the course of fermentation. Serious differences were observed among the strains apparently identical by standard methods.
Protein isolate and other fractions for human consumption from the small‐value fish species black sea minnow (spratus spratus phalericus)
Authors: Dalev P. 
Published: December 2004

AbstractA technology for the fractionation of the small‐value fish species Black Sea minnow (Spratus spratus phalericus) has been proposed. Four valuable fractions with a possibility for utilisation as food and health products have been proposed: the protein isolate, the aminoacid concentrate, the lipid fraction and the fish‐bone fraction.
Biotechnological process for sulphide removal with sulphur reclamation
Authors: Buisman C. , Post R. , Ijspeert P. , Geraats G. , Lettinga G. 
Published: December 2004

AbstractA new biotechnological process for sulphide removal is proposed. The process is based on the oxidation of sulphide into elemental sulphur, which can be removed by sedimentation. In this study it was found that elemental sulphur and sulphate are the main oxidation products of the biological sulphide oxidation. The settling characteristics become worse as the sulphide concentration increases, due to polysulphide formation. The start‐up phase of this biological system is very short; Only four days are needed to reduce the sulphide concentration of 100 to 2 mg/l at a HRT (Residence time) of 22 minutes. Also some environmental factors were evaluated. The optimal pH is situated in the pH‐range 8.0–8.5. Significantly lower conversion rates are found at pH = 6.5 to 7.5 and pH = 9.0, while at pH = 9.5 the sulphide oxidation capacity of the system detoriates. The process temperature was 20°C, although the optimal temperature is situated in the range 25–35°C. No substrate inhibition of sulphide was found at sulphide concentrations up to 100 mg/l.
UV/VIS diffuse reflectance and fluorescence spectroscopy of glucose fermentation with saccharomyces cerevisiae
Authors: Bayer C. , Nagel B. 
Published: December 2004

AbstractUV/VIS diffuse reflectance spectroscopy and fluorescence spectroscopy have been used to investigate the cytochrome and pyridine nucleotide spectra during aerobic biomass growth of Saccharomyces cerevisiae followed by an anaerobic ethanol formation process. The cytochrome and NAD(P)H spectra are closely related to fermentation parameters such as biomass growth rate and ethanol concentration.
Importance of bacteriophages in fermentation processes
Authors: Wünsche L. 
Published: December 2004

AbstractAny bacterial strain can be infected by virulent phages or harbour one or more prophages. Therefore, bacteria‐phage interactions are to be regarded as fundamental properties of bacteria. In current industrial fermentation processes phages can be advantageously employed for the identification of bacterial production strains (phage typing). In some cases phages are involved in the production of enzymes and special substances. The fundamental importance of phages in any technical fermentation process, however, is based on the peculiarities of their obligately parasitic life cycle. The propagation of phages in fermentation processes can cause complete (or at least partial) lysis of the production strains and, consequently, serious disturbances in the production process and considerable economic losses. The phage problem in the fermentation industry has not yet been completely solved. For the protection of technical processes against virulent phages five measures are discussed: phage‐protected sterile fermentation, employment of alternative cultures, employment of phage‐resistant mutants, employment of phage inhibitors, and employment of immobilized bacterial cells. The problem of the protection of bacterial production strains from prophage induction is more difficult and practically unsolved. Two possibilities to minimize the process risk due to temperate phages, the elimination of inducing factors during the fermentation process, and the selection of production strains which are difficult to induce, are discussed.
Irradiation treatment of straw for its microbiological conversion – a method for the production of feed protein
Authors: Peteryaev E. V. , Vetrov V. S. , Pavlov A. V. , Stakheev I. V. , Babitskaya V. G. , Gorbachev V. M. , Glushonok T. G. 
Published: December 2004

AbstractA method for improving the nutritional value of straw as a substrate for fungal growth by radiation is described. The conditions for fungal growth on a medium containing irradiated straw of winter rye were studied. It was found that the straw substrate improves both the quantity of carbohydrates and the quality of their composition in the nutrient medium. Easier accessibility of the irradiated substrate to enzymatic hydrolysis allows the time bioconversion of cellulose into protein to be reduced and the protein yield to be increased, thus improving the qualitative composition of the fungal biomass. The data obtained suggest a possibility of converting straw into a fodder product by substituting the method of using reagents for pretreatment by a simpler and less labour‐consuming method.
Enzyme production by growing cells of acinetobacter in presence of sophoroselipid and triton X‐100
Authors: Hommel R. , Götzrath H. , Kleber H.‐P. 
Published: December 2004

AbstractThe effects of an extracellular microbial glycolipid, the interfacial active lactonic sophoroselipid, and of Triton X‐100 on strains of Acinetobacter calcoaceticus are compared. Sophoroselipid diminished growth rates on n‐heptadecane. Both surfactants led to the excretion of enzyme activities into the culture medium. Sophoroselipid increased the release of cytoplasmic malate dehydrogenase whereas in presence of Triton X‐100 the quinoprotein glucose dehydrogenase was also excreted in large amounts.
Characterization of biotechnological processes and products using high‐performance liquid chromatography (HPLC) V. Analysis of organic acids in the 2‐oxo‐D‐gluconic acid synthesis
Authors: Gey M. , Thiersch A. , Rietzschel A. , Nattermueller W. , Stottmeister U. , Nagel B. 
Published: December 2004

AbstractA HPLC method for the separation of 2‐oxo‐D‐gluconic acid and 5‐oxo‐D‐gluconic acid was developed and applied to the investigation of the microbial glucose conversion to oxogluconic acids.Using a strongly basic anion‐exchange resin TEAP‐Si 100 Polyol as stationary phase and HCOOH as mobile phase, the oxogluconicacids could be separated. The method was used to investigate the kinetics of product formation during the microbial oxogluconic acid synthesis.
Biosensoren für die Lebensmittelindustrie
Authors: Liebs P. , Riedel K. , Pfeiffer D. , Zimare U. , Lietz P. , Scheller F. 
Published: December 2004

AbstractBiosensors are obtaining an increasing significance for analytical purposes as well as for on‐line monitoring and control in biotechnological processes [1]. In the special field of food industry enzyme and microbial biosensors are suited. With enzyme sensors one can analyse in mostly high specific reactions many substances – microbial sensors normally are unspecific. But they have the advantage of high stability and there is no necessity of enzyme isolation and purification. On the basis of the manifold of microbial metabolic pathways one can expect a wider range of application for microbial sensors, much more as existent for enzyme sensors. This paper is dealing with a microbial aspartam sensor.
Industrielle Meßgeräte zur Bestimmung der Trübung von Flüssigkeiten
Authors: Geppert G. , Thielemann H. , Langkopf G. 
Published: December 2004

AbstractThree different instruments for the determination of turbidity in liquid media are described. The SLP‐2 was developed for the control of high biomass concentrations in fermenters and is fitted with a self‐cleaning mechanism. The SLP‐3 is used for control of very small turbidities, e.g. in brewery products or in drinking water. The SLP‐4 is designed for continuous measurement of higher turbidities in (waste) water or in different products flowing through pipe‐lines. It may be used alternatively as a submerged probe.
Simultaneous saccharification and fermentation of cellulose: Effect of ethanol and cellulases on particular stages
Authors: Szczodrak J. , Targoński Z. 
Published: December 2004

AbstractThe effects of ethanol and Trichoderma reesei cellulase on the saccharification and fermentation processes as well as the tolerance of the cellulase complex for ethanol have been investigated. The studies were conducted with respect to their usefulness in the process of simulataneous saccharification and fermentation of cellulose to ethanol. The following results were obtained. (1) Fermentative activity of Kluyveromyces fragilis yeasts was gradually depressed with increasing intial ethanol concentrations and temperature of fermentation between 35–46°C. (2) Crude cellulase preparation introduced to the culture broth to a final enzyme activity of 0.5 to 2.0 FPU/ml had not distinct effect on the biomass production, ethanol yield, and glucose uptake by yeasts in 48 h fermentation at 43°C. On the other hand, only a negligible decrease in the cellulase complex activity was observed during fermentation process. (3) Saccharification of wheat straw was inhibited by at least 1% w/v ethanol. (4) The enzymes of the cellulase system showed a high stability to exposure to ethanol for 48 h at 43°C.
A survey of problems relating to legal protection of genetic engineering inventions
Authors: Pehu T. , Gyllenberg H. G. 
Published: December 2004

AbstractIn the first patent applications in the field of genetic engineering the main problems were the terminology and the definition of various concepts. This was mainly due to the fact that the field of genetic engineering was new to the patent officials as well as to the patent attorneys. At the moment the terminology and the concepts have already become familiar and patent problems also in the microbiological sector are merely technical. However, new exiting problems have arisen because of the rapid development in the field of plant and animal biotechnology. A lot of work is still needed before the patent system fulfills its purpose as a promoter of technical, economical and social progress also in the field of biotechnology.
Use of antibodies to the lipopolysaccharide core region in the treatment of gram‐negative sepsis and shock
Authors: Appelmelk B. J. , Verweij‐van Vught A. M. J. J , Brade H. , Cohen J. , Maaskant J. J. , Thijs L. G. , Mac Laren D. M. 
Published: December 2004

AbstractIn this paper we review evidence in favor of a protective role for antibodies directed at the lipopolysaccharide (LPS) core region of Gram‐negative bacilli. It will be shown that, given the right animal model, polyclonal antisera raised against O‐antigen lacking, rough mutant strains, can be shown to protect animals against lethal sepsis due to a variety a bacterial species. Evidence for a protective role obtained from clinical studies will also be discussed. It will be stressed how difficult it is to prove that the antibodies directed against the LPS‐core, and not other proteins present in the polyclonal anti‐rough strain antisera, were responsible for the observed protective effects. The solution to some of these problems is the production of monoclonal antibodies (Mabs). We will discuss the findings that purified anti‐core Mabs may give false‐positive outcomes of protection studies, due to the induction of tolerance by small amounts of contaminating endotoxin, present in the antibody preparation. The need to administer the Mab therapeutically instead of prophylactically to the test animals, will be stressed. It will be shown how we succeeded in determining the epitope‐specificities of several anti‐core antibodies. It will be shown also that use of Elisa alone for characterization of anti‐core Mabs may lead to false conclusions concerning epitope specificities. We will prove that synthetic KDO‐(=ketodeoxycctanate) and lipid A‐containing antigens are indispensable tools for thorough characterization of Mabs. Using this methodology we were able to discriminate between specific antigen‐antibody interactions, and the ability of some Mabs to bind “non‐specifically” to hydrophobic surfaces. The relationship between epitope specificity and protective effects of anti‐core Mabs will be described. Finally, we will demonstrate that a KDO‐specific Mabs is capable of protecting mice against lethal sepsis; in other words, it will be shown conclusively that Mabs to defined epitopes in LPS core region are cross‐protective.
Ethanolic fermentation with saccharomyces cerevisiae cells immobilized in pectate gel
Authors: Rühlemann I. , Richter K. , Berger R. 
Published: December 2004

AbstractHigh‐molecular weight pectic acid with a STAUDINGER index of 210 ml/g and a degree of esterification of 3%was used as matrix material for the immobilization of Saccharomyces cerevisiae cells. In discontinuous and continuous fermentation tests the gel beads obtained exhibited the same biomass loading capacity (152–155 g dry wt. cells/kg gel) and about the same maximum specific productivity (103.0 g ethanol/kg gel · h) as alginate immobilizates. But there were distinct differences in the swelling behaviour of the two gels. Under the same experimental conditions the increase of bead volume amounted to 27% only for pectate gel in comparison to 129% for alginate gel. In continuous fermentation experiments performed in a horizontal‐column packed‐bed reactor with liquid recycling a mean steady‐state ethanol concetration of 69.1 g/l and a mean productivity of 24.7 g ethanol/lh could be kept constant over a period of more than 10 days.