bluuebunny/crossref_metadata_2025_split huggingface dataset:
Practical aspects of the mathematical modeling of fermentation processes as a method of description, simulation, identification and optimization
Authors: Votruba J. 
Published: December 2004

AbstractMost mathematical models for describing the physiological state in fermentations lead to solutions of the so‐called “stiff differential systems” during simulation on a digital computerThere is no suitable conventional software for solving these systemsAs a result of a relatively extensive screening of suitable methods for the solution of “stiff” differential systems (about 200 methods) it may be concluded that the semiimplicit RUNGE‐KUTTA‐formulas of the ROSENBROCKtype, which constitute a part of the collection of programmes STIFFSOLVER‐80, are optimal for the simulation of fermentation processesFor determining kinetic parameters from integral data the authors use the system of programmes BIOKINTheir practical application is discussed for 3 examples:Growth of the yeastSaccharomyces cerevisiaeand changes in the content of specific compounds (proteins and ergosterol)Quantitative evaluation of “;direct oxygen transfer” in the submerged culture.Biosynthesis of a new antibiotic substance mucidin.
Factors affecting growth and cellulose hydrolysis by the thermotolerant aspergillus nidulans from composts
Authors: Ogundero V. W. 
Published: December 2004

AbstractThe ability of Aspergillus nidulans (EIDAM) WINT to grow and sporulate at various temperatures and to degrade soluble and insoluble forms of cellulose were studied. A. nidulans was found to grow and sporulate best at 37°C in continuous light and alternating light‐darkness respectively. The fungus was able to cause losses in the dry weights of filter papers on incubation and made appreciable growth on CMC and hemicellulose. The culture filtrates contained cellulases which hydrolysed filter papers and CMC to reducing sugars, and were only able to produce these enzymes in the presence of cellulose or its derivatives in the growth medium. The CM‐cellulases had peak activity at pH 5.2 and at 50°C while optimal FP‐activity occurred at a pH of 5.5 and at 45°C. The participatory role of A. nidulans in composting is discussed.
Electrophysical methods of monitoring biosynthesis
Authors: Sedykh N. V. , Chirkov I. M. 
Published: December 2004

AbstractElectrophysical devices with standard sensors were used for measuring the principal electrophysical parameters of raw materials, microbiological suspension and biopreparations: their dielectric constant, tangent of dielectric loss angle, specific conductivity and duration of dielectric relaxation of the medium. The obtained characteristics proved ot be rather informative for monitoring different technological parameters of the biosynthesis. The applicability of electrophysical methods in monitoring the process of biosynthesis was substantiated with examples.The electrophysical methods provide a simple and reliable way of monitoring the technological parameters in technical microbiology.
New developments in the field of protein enrichment of foods and feeds (P.E.F.F)
Authors: Senez J. C. 
Published: December 2004

AbstractUp to the year 2000 the total demand of protein for animal feeding will rise by 146%. This demand can not be covered by agriculture alone. According to FAO data it will be an expected deficit of some 400 million tons of cereals at this time all over the world. Therefore the large scale industrial production of SCP from alkanes, methanol and other raw materials will undoubtely become soon an absolute necessity. On the other hand, a new process of solid state fermentation (ORSTOM/IRCHA process) having special interest for the developing countries has been recently set‐up in France.Based on dried and crushed potatoes or cassava (manioc or tapioca) protein enrichment by fermentation of feeds of foods (PEFF) in a simple manner without aseptic conditions with the filamentous fungus Aspergillus hennebergii is carried out. The process is presently optimized and scaled‐up to the size of a 700 kg (dry weight) fermenter.Nutrititional and toxicological assays have demonstrated complete safety and excellent nutrititional value of the product, which is applicable as a feedstuff for breading of e.g. pigs or chickens.
Stirrer and peristaltic pump agitated fermenter
Authors: Nikolajewski H. E. , Meineke L. , Wettig G. 
Published: December 2004

AbstractA fermenter has been designed for aerobic cultivation processes with stirrer and external peristaltic pump to provide high oxygen transfer rate along with low foam formation. Aerobic growth experiments conducted with E. coli gave an oxygen transfer to ensure a maximum growth rate of about 9 g dry weight/l h. In all tests performed foam never reached a critical level.
Zum Einfluß der physikalischen Struktur des Substrates auf die Hydrolyse von Cellulose durch verschiedene Enzymsysteme und Enzymkomponenten
Authors: Philipp B. , Dan D. C. , Fink H.‐P. , Eriksson K.‐E. , Pettersson B. 
Published: December 2004

AbstractStarting from cellulose samples prepared from cotton lintes and differing in lattice type, crystallinity and fibrillar morphology, enzymatic hydrolysis of fibre cellulose has been studied employing complete enzyme systems from Trichoderma, Sporotrichum, Gliocladium and Penicillium as well as isolated endo‐ and exo‐1,4‐β‐glucanases from Trichoderma reesei and Sporotorichum pulverulentum. The effect of hydrolysis was characterized by content of reducing sugars (RS) and of glucose in the hydrolyzate as well as by DP and X‐ray diffraction pattern of the residues. With all the complete enzyme systems investigated about the same order of degradability was found with a series of substrates differing in physical structure. The hydrolysis effect of cellulase from S. pulverulentum proved to be sensitive to the gas atmosphere above the system (N2 or O2), probably due to the interaction of an O2‐atmosphere with the activity of the cellubiose‐oxydase existent in the system. Isolated endoglucanase from S. pulverulentum and T.reesei still led to a considerable formation of RS and glucose, a corrosion of the fibre surface and a significant descrease in DP. Influence of substrate physical structure was rather small with regard to RS, but still considerable with regard to residue‐DP.The effect of isolated exoglucanases depends largely on the chemical structure of the cellobiohydrolase in question, as demonstrated with the two samples “CBH I” and “CBH II” from T. reesei. With CBH I, rather resembling endo‐glucanase behaviour, a considerable formation of RS and a significant corrosion of the fibre surface has been observed. On the other hand, only negligibly small amounts of RS were formed by CBH II.Results are discussed with regard to the complex mechanism of cellulase action on fibrous cellulose and with regard to the relevance of different parameters of physical structure of cellulose in connection with enzymatic hydrolysis. A remarkable acceleration of the Cellulose III → Cellulose I lattice transition due to chain fragmentations in the presence of cellulase can be concluded the experiments.
The optimization of L‐lysine fermentation and a mass transfer model
Authors: Hilliger M. , Möckel H.‐O. , Forberg W. 
Published: December 2004

AbstractThe efficiency of L‐lysine biosynthesis is essentially determined by the power input and aeration ratio in the stirred fermenter.A mass transfer model was developed by means of the results of lysine fermentations in four geometrically similar fermenters with working volumes of 10 1, 50 1, 100 1 and 2500 1 which allows the optimization of lysine fermentation from the energetical point of view. The usefullness of this kLa‐model is demonstrated with an example where the power input for an unknown fermenter is calculated.
Experimentelle Untersuchung, Modellierung und optimale Berechnung eines mehrstufigen Säulenfermentors. I. Theoretische Analyse und Synthese des mathematischen Modells
Authors: Kafarov V. V. , Vinarov A. J. , Gordeev L. S. , Semenova E. A. 
Published: December 2004

AbstractA model of the process of aerobic fermentation in a tower fermenter devided in sections was established and examined by experiments.In this part data for the concentration of biomass, substrate and oxygen in the sections of the bioreactor at countercurrent moving of the phases were characterized.
Horseradish peroxidase based bienzyme elctrode for isocitrate
Authors: Schubert F. , Kirstein D. , Abraham M. , Scheller F. , Boross L. 
Published: December 2004

AbstractCoimmobilized horseradish peroxidase and D‐isocitrate dehydrogenase were fixed to an oxygen electrode to assemble a bienzyme electrode for isocitrate determination. The linear measuring range for isocitrate of the sensor is between 0.1 and 2.0 mmol. I−1, the coefficient of variation (20 measurements) is 3.6%. 8 samples per hour can be assayed. With one sensor preparation 140 measurements can be carried out.
Klonierung von RSV‐cDNS (Respiratiorisches Syncytial Virus) und erste Charakterisierung der Rekombinanten
Authors: Prösch S. , Seidel W. , Döhner L. , Liebscher D. H. 
Published: December 2004

AbstractGenomic RNA of the Respiratory syntical virus (RS‐virus) was used as a template to synthesize calfthymus DNA‐primed cDNAs. These cDNAs were subsequently cloned into the E. coli plasmid pBR 322 at the PstI‐site. By hybridization 6 recombinants with virusspecific cDNAs representing 10% of the whole genome could be isolated.
Der Einfluß der Prozeßparameter auf die Ethanolausbeute in Batchprozessen bei Verwendung von Saccharomyces cerevisiae
Authors: Becker U. , Richter K. , Nickel A. 
Published: December 2004

AbstractThe production costs of ethanol are dependent on the efficiency of the substrate‐ethanol conversion to a high degree. The more the substrate used during the fermentation is converted into alcohol the better is the economy of the process.Therefore the ethanol yield Y SP is an important object of the process optimization.In batch fermentation processes the most essential influence factors are the initial biomass concentration X0, the initial substrate concentration S0, the temperature T, and the pH‐value.A model reflecting the complex relationships between these influence factors and the ethanol yield could be obtained by regression. It allows an exact valuation of these optimum process parameters which are necessary for realizing high ethanol yields in the batch fermentation.For the strain Saccharomyces cerevisiae Sc 5 used in this research was found an ethanol yield maximum YSP = 0˙5384 at the parameters
X0 = 64.61 g/l
S0 = 82.91 g/l
T = 36.45°C
pH = 6.54.
Biological method for ethanol determination
Authors: Blumbergs J. E. 
Published: December 2004

AbstractIt has been demonstrated that on an alkaline medium starving yeast Saccharomyces cerevisiae 14 oxidizes ethanol to acetate at a very high rate, consuming oxygen in stoichiometric ratios. This phenomenon can well be used for ethanol determination. This method is advantageous for its simplicity, cheapness and responsiveness.
Untersuchungen zur Sauerstoffdiffusion in wäßrigen Xanthanlösungen
Authors: Stottmeister U. 
Published: December 2004

AbstractThe determination of oxygen diffusion coefficients was carried out by a modified chronoamperometric method using a stationary platinum electrode.The determined diffusion coefficients are related to approximated η0‐values.It was shown a relation of Di and η0 according to the HAYDUK‐CHENG‐potential equation.That means a strong relative lowering of oxygen diffusion coefficients already by low viscosities, but a little influence at high viscosities.A simple laboratory thin film reactor is described, in which the oxygen supply is maintained by diffusion. This reactor is suitable very well for fermentations of viscous fluids.
Experimentelle Untersuchung, Modellierung und optimale Berechnung eines mehrstufigen Säulenfermentors II. Experimentelle Bestimmung der Parameter und Koeffizienten des mathematischen Modells
Authors: Kafarov V. V. , Vinarov A. J. , Gordeev L. S. , Semenova E. A. 
Published: December 2004

AbstractUsing a system analysis for the investigation of all processes which occur in a biochemical reactor on the micro and macro level, a mathematical model was worked out. It characterizes the model of the kinetics and stoichiometry of the growth of microorganisms and the rules of hydrodynamics and mass transfer in form of blocks. Relating to the discussed mathematical total model [11], experimental data on which the calculation of the model parameters is based are described in this second part of the paper. They were determined not only directly from the cultivation process, but also from experiments with model media.
Ein neues System von Begasungsbrutschränken für die Biotechnologie
Authors: Beckmann D. , Metze J. 
Published: December 2004

AbstractThe experiences in the production of CO2‐incubators [1] have been the basis for the development of a system of gassing incubation cabinets, which, starting from a basic structure with temperature and humidity control (climatic test cabinets), consist of modular built up devices with regulating circuits for carbon dioxide and oxygen content of the incubation room atmosphere. The performance of the system is considerably extended by the equipment of the devices with a microcomputer system, by which the dynamic control of the parameters of the incubation room atmosphere is possible the first time.Essential mark of the system is further the standardized structural module for all devices and the flexibility in the equipment of the incubation room according to the demands of special tests.
Optimal production of cellulolytic enzymes and their location in trichoderma pseudokonigii
Authors: Kalra M. K. , Sandhu D. K. 
Published: December 2004

AbstractThe maximum production of cellulose enzymes (FPactivity, CMcellulase and β‐glucosidase) in the culture filtrate was observed at 27°C and pH 5.0, except for β‐glucosidase, being at 6.0. The levels of extracellular enzymes in shake and stationary culture conditions was almost equal although they reached their maxima earlier in the former. The distribution of the three enzymes in extracellular, cytosol and cell debris fractions revealed most of the FPactivity and CMcellulase occurring extracellulary. More than 50% of the β‐glucosidase was present in the cell debris fraction.
Production, characterization and use of expendable kefir starter culture in the kefir production process
Authors: Kramkowska A. , Fesnak D. , Kornacki K. , Bauman B. 
Published: December 2004

AbstractUpon sterilization, freeze‐dried kefir grains are to be supplemented with yeast preparation, yeast showing the lowest survival in the course of freeze drying.A mixture of 20% sucrose solution and starch appeared to be the most efficient dispersing agent to protect yeast in the freeze‐drying process.A starter which is produced with the kefir starter culture, does not differ in its microbiological, biochemical and organoleptic properties from a starter as obtained with kefir grains in the same time, such starter shows a better consistency.The preparation of such starters is less laborious and less complicated than the preparation of starters using kefir grains.
Mechanismen des Wassertransportes bei der Getreideweiche
Authors: Mohr K.‐H. 
Published: December 2004

AbstractA simple method for the investigation of the water transport velocity in cereal kernel is described. The mechanism of the water transport is discussed. It is explained that data, place and strength of the effect of hydrolytic enzymes can be determined on the basis of the changed transport resistance from the temporal change of the different diffusion coefficient. The fundamentals of the modelling of steeping processes are given.
Inhibitory effects of ethanol in alcoholic fermentation
Authors: Richter K. 
Published: December 2004

AbstractThe ethanol tolerance behaviour of the strain Saccharomyces cerevisiae Sc 5 regarding the growth is characterized by a threshold ethanol inhibitory concentration (P1' = 42.5 g/l) and a linear relationship between the specific growth rate and the ethanol concentration within the limits P1' < P < P′. The maximum ethanol concentration for growth amounts to P′ = 84 g/l.A general model for the inhibition of growth and alcohol production, respectively, caused by ethanol, is deduced from experimental and bibliographical data:

If the inhibitory effects are linear, the exponents b, b' become 1.
Formation and release of β‐glucosidase by aspergillus niger zimet 43 746 in correlation to process operations
Authors: Kerns G. , Dalchow E. , Klappach G. , Meyer D. 
Published: December 2004

AbstractThe total formation of β‐glucosidase by the wild strain of Aspergillus niger ZIMET 43 746 is non‐growth‐associated. In discontinuous culture the total β‐glucosidase activity related to the mycelium is incresing with the age of the mycelium. The complete release of the remaining mycelial‐associated β‐glucosidase is dependent on the structure of the mycelium. In the cases of the mycelium forms pellets throughout the growth phase than the release of β‐glucosidase is accelerated compared to the release from loosly branched mycelium. Incresing shear stress caused by increasing of the impeller speed promotes the formation of pellets.
Zur mixotrophen Kultivation von Chlorella vulgaris in homokontinuerlicher Chemostatkultur
Authors: Roth P. , Bürger S. 
Published: December 2004

AbstractCells of Chlorella vulgaris, BEIJ. Greifswald 9, were grown on autotrophic and mixotrophic conditions using glucose and acetate as organic substrates. It was shown that these C‐sources applicated in a suitable range of concentrations increase the growth rate and the productivity of the algal cultures. The cells grown on mixotrophic conditions have a higher total pigment content and exhibit variations in the ratio chlorophyll a/chlorophyll b.In addition the contents of proteins, lipids, carbohydrates, and nucleic acids of the biomass were shown to be dependent on the kind of the organic substrate used.
Assimilation of methanol by Yeasts
Authors: Jwanny E. W. , Rashad M. M. 
Published: December 2004

AbstractCandida lipolytica was cultured on a methanol containing medium as the only C source. The influence of different concentrations of methanol and ammonium sulphate and the effect of addition of some biological active materials to the methanol containing medium were studied.Dry cell yield of C. lipolytica and protein content were determined to be 23.1 g of cells/100 g of methanol added and 40.2%, respectively. Total lipids, phospholipids, keto acid and amino acid composition were estimated. The amino acid composition of the protein was comparable to the composition of the other reported single cell proteins (SCP). These results indicate that C. lipolytica is potentially important for fodder use.
Abhängigkeit der dimensionslosen Mischgeschwindigkeit (n/K) von der Re‐Zahl bei einem dreistufigen Rührersystem
Authors: K.‐H. Wolf , Stiebitz O. , Venus J. 
Published: December 2004

AbstractThe mixing‐time characteristic in the three‐stage stirrer system is analyzed for the range of 6 ˙ 104 ≦ Re ≦ 3.2 ˙ 105 using the pH‐method. Different from the one‐stage systems, for the baffled reactor (BW = 0.8) it was estimated that the homogenized number increases with cH ∼ Rem (m = 0.77). Obviously, between two stirrers it exists a kernel sphere with a delay mass transfer in consequence of low axial current components.The measurements can be described with high significance by the model for dimensionsless “mixing‐rate number” of KHANG and LEVENSPIEL.
Continuous Fermentation in high flow rate fermenter systems
Authors: Richter K. , Becker U. , Meyer D. 
Published: December 2004

AbstractIn commercial batch processes the productivity of product formation is low. But a significant increase of productivity can be achieved in continuous fermentations. By using high flow rate fermenter systems characterized by a relatively long retention time of biomass in comparison with the retention time of the liquid we can realize a high‐performance fermentation. The problem of holding back the biomass within the reactor could be solved by means of membranes being impenetrable to the cells, but permeable to the hydraulic phase. Such a process technology was successfully tested for its applicability in alcoholic and lactic acid fermentations. The maximum productivities obtained on this way were ṗ = 120 g/l. · h for ethanol production and ṗ = 51 g/l. h for lactic acid fermentation, respectively.
Untersuchung von Bestandteilen der Zuckerrübenmelasse, die auf Aspergillus niger bei der Citronensäureproduktion toxisch wirken
Authors: Druri M. , Żakowska Z. 
Published: December 2004

AbstractSeveral fractions of ether extracts of beet molasses separated by chemical and chromatographic methods were found to be toxic for Aspergillus niger. Addition of these fractions to growth medium caused sinking of the mycelium in the culture broth and irregular growing of the test strains. Fermentation tests carried out on molasses media in the presence of the toxic fractions showed a different susceptibility depending on the used strain. From one fraction n‐alkanes with 16 to 36 carbon atoms were isolated by thin‐layer chromatography and identified using IR and GC methods. These compounds originated in molasses probably from chemical additives used in the sugar manufacture plant.
Eiweißbiosynthese aus Lignozellulose enthaltenden Rohstoffen
Authors: Ilnicka‐Olejnickzak O. , Czajkowska D. , Targonski Z. 
Published: December 2004

AbstractThe object of the presented studies was to determine the conditions of protein biosynthesis from lignocellulosic raw material using filamentous fungi.It was found that on beet pulp + 50% wheat straw, strain A. niger (A.n./61) shows the highest effectivity of protein biosynthesis. Using this strain, after 48‐hour incubation the following results were obtained: increase in protein 4.43 g/100 g˙DM, daily protein increase coeffizient 2.22 g/100 g DM x 24 h, protein yield (based on the decrease in dry matter) 22.3% and cellulose utilization 37%.Upon use of a new strain CEL 2 and milled wheat straw as the substrate, the best results obtained after 74‐hour incubation were as follows: increase in protein 1.82 g/100 g DM, daily protein increase coefficient 0.61 g/100 g DM x 24 h, protein yield 15,8% and cellulose utilization 22.0%.For rape straw and strain Sporotrichum pulverulentum, after 192‐hour cultivation the following results were obtained: increase in protein 5.4 g/100 g DM, daily protein increase coefficient 0.68 g/100 g DM x 24 h, protein yield 14% and cellulose utilization 50.2%.
Bioakkumulation und Biosorption zur Detoxifikation und Entfernung von Metallen
Authors: Glombitza F. , Iske U. 
Published: December 2004

AbstractGrowing and resting cells of microorganisms are able to accumulate metal ions.These reactions are based on a storage within the cells as well as sorption at the cell wall.The intracellular storage takes place preferably by growing cells.The stored amounts of metals by resting cells depend on the concentration of metal ions in the aqueous phase, the pH‐value, and, in some cases on the temperature.Maximum concentrations for some metals and strains of microorganisms are given.The representation of the uptake reaction as an adsorption process using a FREUNDLICH‐Isotherm demonstrates straight lines with different clopes.The removal of the metals from the biomass by a desorption reaction is possible in some cases, other possibilities are a reducing process or the formation of an ash of the biomss containing compounds of metals.These reactions may be used simultaneously for detoxification and removal of metals from waste water.