bluuebunny/crossref_metadata_2025 huggingface dataset:
Survey of Pathogens in Juvenile Salmon Oncorhynchus Spp. Migrating through Pacific Northwest Estuaries
Authors: Arkoosh M. R. , Clemons E. , Kagley A. N. , Stafford C. , Glass A. C. , Jacobson K. , Reno P. , Myers M. S. , Casillas E. , Loge F. , Johnson L. L. , Collier T. K.
Published: December 2004

Although the adverse impact of pathogens on salmon populations in the Pacific Northwest is often discussed and recognized, little is currently known regarding the incidence and corresponding significance of delayed disease-induced mortalities. In the study reported herein, we surveyed the presence and prevalence of selected micro- and macroparasites in out-migrant juvenile coho salmon Oncorhynchus kisutch and Chinook salmon O. tshawytscha from 12 coastal estuaries in the Pacific Northwest over a 6-year period (1996–2001). The major finding of this study was the widespread occurrence of pathogens in wild salmon from Pacific Northwest estuaries. The six most prevalent pathogens infecting both juvenile Chinook and coho salmon were Renibacterium salmoninarum, Nanophyetus salmincola, an erythrocytic cytoplasmic virus (erythrocytic inclusion body syndrome or erythrocytic necrosis virus), and three gram-negative bacteria (Listonella anguillarum, Yersinia ruckeri, and Aeromonas salmonicida). The most prevalent pathogen in both Chinook and coho salmon was N. salmincola, followed by the pathogens R. salmoninarum and the erythrocytic cytoplasmic virus. Statistically significant differences in the prevalence of R. salmoninarum and N. salmincola were observed between Chinook and coho salmon. Based on the prevalence of pathogens observed in this study, disease appears to be a potentially significant factor governing the population numbers of salmon in the Pacific Northwest. Development of a detailed understanding of the principal components influencing the ecology of infectious disease will aid in the development of management and control strategies to mitigate disease in and hence further the recovery of salmon stocks listed under the Endangered Species Act.
Effect of Sublethal Exposure to the Trematode Bolbophorus spp. on the Severity of Enteric Septicemia of Catfish inChannel Catfish Fingerlings
Authors: Labrie Lauke , Komar Cedric , Terhune Jeff , Camus Alvin , Wise David
Published: December 2004

The digenetic trematode Bolbophorus damnificus has been implicated as a cause of mortalities and reduced production in farmed channel catfish Ictalurus punctatus in northwestern Mississippi. Field observations indicate that infection can exacerbate losses from common bacterial diseases, such as enteric septicemia of catfish (ESC), which is caused by Edwardsiella ictaluri. The interaction of concurrent infections with Bolbophorus spp. and E. ictaluri was investigated using three replicates of four experimental treatments. Trematode infections were established by placing fingerlings for 24 h in triplicate static tanks containing marsh rams-horn snails Planorbella trivolvis shedding Bolbophorus cercariae at a rate of 770 ± 82 (mean ± SE) per 24-h period. Unexposed fish were maintained in three tanks under similar conditions. From each tank, trematode-infected or noninfected fish were transferred to six aquaria (30 fish/aquarium). Three aquaria from each replicate treatment tank received 7.5 × 105 colony-forming units (CFU) of E. ictaluri/mL of water for 30 min (Bolbophorus–ESC and ESC-only groups). Fish in the remaining three aquaria were not exposed to E. ictaluri and served as Bolbophorus-only and negative control groups. No mortalities were observed in the Bolbophorus-only and negative control groups. Twenty-one days after exposure to E. ictaluri, the percent cumulative mortalities were 84.1 ±16.2% in the Bolbophorus–ESC treatment and 45.9 ± 3.2% in the ESC-only treatment. Mortalities were significantly different between the two groups (P = 0.0161). In a second study, fingerlings were challenged with E. ictaluri 28 d after trematode exposure; 21 d later, no differences in cumulative percent mortalities were observed between trematode-infected (21.5 ± 1.7%) and trematode-negative (17.8 ± 4.01%) fish. These studies show that sublethal Bolbophorus infection increases mortalities from E. ictaluri when exposure occurs simultaneously but not when ESC infection occurs 28 d after trematode exposure.
Vibrio Bacterin and Carboxymethyl β-1,3-Glucans Protect Penaeus monodon from Vibrio harveyi Infection
Authors: Klannukarn Supattra Somapa , Wongprasert Kanokpan , Khanobdee Kornnika , Meeratana Prasert , Taweepreda Pattira , Withyachumnarnkul Boonsirm
Published: December 2004

The aims of this study were to determine the effects of Vibrio bacterin, with or without carboxymethyl β-1,3-glucans (CMBG), on the protection of black tiger shrimp Penaeus monodon against V. harveyi infection, and to determine the mechanisms underlying the protection. The study was done with two groups of shrimp, one in short-term treatments in concrete tanks and the other in long-term treatment in commercial ponds. Healthy juvenile black tiger shrimp were provided with formalin-killed V. harveyi (bacterin) and CMBG, which were top-dressed on commercial pellets, for 10 d. They were then challenged with virulent V. harveyi and the relative percent survival (RPS) was determined. The shrimp hemolymph was also studied to determine hemocyte counts and phagocytic, bactericidal, and phenoloxidase activities. In the commercial ponds, the shrimp were given commercial pellets top-dressed with the two substances for 2 months. The shrimp were sampled and challenged with virulent V. harveyi and the RPS determined. In the experimental tanks, the shrimp receiving the bacterin, CMBG, and the combination thereof survived better than the control. After 10 d of the treatments, total hemocyte counts and their individual types (hyalinocytes, semigranulocytes, and granulocytes) were significantly increased. The levels of phagocytosis of hemocytes, bactericidal activities of mixed cell and hemocyte fractions, and prophenoloxidase of hemolymph lysate supernatant fluids were significantly higher than those of the control group. Protection against V. harveyi of shrimp from the commercial ponds treated with bacterin and CMBG was also detected as judged from the greater than 60% RPS in most cases. In all the parameters tested, no significant differences were detected among the shrimp treated with bacterin, CMBG, or the combination thereof. These studies suggest that both bacterin and CMBG could separately induce internal defenses of the shrimp against V. harveyi infection and that the mechanisms include stimulation of the shrimp's cellular and humoral factors.
Production of xylanase by streptomyees xylophagus nov. sp.
Authors: Tangnu S. Kishen , Blanch H. W. , R.Wilke Ch.
Published: December 2004

Die Xylanaseproduktion durch Streptomyces xylophagus nov. sp. wurde im Schü ttelkolben und in einem 14‐Liter‐Laborfermentor in diskontinuierlicher und in kontinuierlicher Kultur untersucht. Die maximale Enzymausbeute wurde auf 1%igem handelsü blichen Xylanmedium bei 30°C durch 7,5%ige ü berimpfung einer 5 Tage alten Xylankultur erreicht, wobei dem Medium im Schü ttelkolben 0,8% und dem Submersfermentor 0,3% Bactopepton zugestzt wurden. Die maximale Xylanaseproduktion wurde bei pH 7,4 erreicht. Eine Hitzbehandlung bis zu 200°C wirkte sich nicht hemmend auf die Xylanaseproduktion aus.

Die Gleichgewichtsparameter fü r die Zellmasse, lösliches Protein und die Xylanaseaktivitä t wurden in Abhä ngigkeit der Verdü nnungsraten von 0,02 bis 0,04 h+1 bestimmt, wobei Xylan (wood gum xylan) als Kohlenstoffquelle diente. Die maximale Enzymaktivitä t und Produktivitä t von 7,2 X.U. (1 xylanase unit, X.U. ≙ 1 mg reduzierter Zucker, der aus 1 ml Enzym in 15 Minuten bei 50°C gebildet wird) und 0,194 X.U./h wurden bei einer Verdü nnungsrate von 0,027 h+1 beobachtet.

Die maximale Zellkonzentration und Produktivitä t von 7,2 g/l und 0,245 g/lh wurden bei einer Verdü nnungsrate von 0,34 h+1 beobachtet.
Growth characteristics of a thermotolerant strain of lodderomyces elongisporus grown on sucrose
Authors: Schneider J. D. , Hänsel R. , Hedlich R. , Jechorek M.
Published: December 2004

A thermotolerant yeast species of Lodderomyces elongisporus EH 60 was isolated and physiologically characterized. This yeast possesses a high specific growth rate with μmax = 0.61 h−1. The dependence of the specific growth rate and cell yield on temperature, dilution rate, sucrose concentration and pH‐value is investigated. Sucrose concentrations greater than 10 g/l inhibit the growth velocity.

The specific growth rate μ can be calculated by a simple combination equation in the form:

.

The total optimum values for a sucrose‐based continuous growth process with regard to the optimum cell yeild are: YS = 0.50 g DM/g S. Topt. = 38,6 °C and Dopt. = 0,35 h−1. The function YS = f(D, T) is represented by a total model.
Saccharification of cassava (manihot esculenta) with millet amylase
Authors: Opoku A. , Uraih N.
Published: December 2004

Millet amylase formed during malting was used for teh saccharification of cassava (Manihot esculenta) into glucose syrup. The resulting syrup was also fermented to ethanol and citric acid. The maximum α‐amylase activity occurred within 30 hours of millet germination at an optimum pH 8.0 and 40°C. The T. reesei enzymes enhanced the rate of cassava hydrolysis and paper chromatography revealed the presence of maltose, glucose and galactose in the cassava hydrolysate. The low cost of millet coupled with the fact that it is readily available makes it an economic source of amylase.
Preliminary results in the fluorometric investigation of fermentation processes
Authors: Schmidt A. , Kuchenbecker D. , DÄBeritz H.
Published: December 2004

A flow cuvette for fluorescence exciting and measuring directly on the surface of fermentation broths was developed. Compared with the commonly used cuvette the disturbances by inhomogeneities of the samples and by the inner filter effect could be lowered to an appreciable extent.
Untersuchungen zur Separation aufgeschlossener Hefesuspensionen
Authors: Luther H. , Claus A. , Büttner W , Schuster E.
Published: December 2004

By the means of the electronic particle counting, characteristics of industrial contrifuges are found out in order to characterize the performance in the case of the separation of cell debris of mechanically disrupted yeast cells. The knowledge about the particle size distribution complements the usual determination of the dry matter content in the supernatant. Thus an optimization of the separation of tiny particles is facilitated.
Enzymologie der n‐alkanoxidation bei acinetobacter
Authors: Kleber H.‐P. , Claus R. , Asperger O.
Published: December 2004

Enzymology of n‐alkane degradation was studied by using different Acinetobactersp¨︂ Cell‐free extracts of A. calcoaceticus69/V oxidize the n‐alkane to the corresponding fatty acid via the intermediately formed n‐alkanol Soluble and particulate components are necessary for activity. Independently, a rubredoxin and a NADH‐dependent rubredoxin reductase were isolated from this strain. Rubredoxin is induced by n‐alkanes. The occurence of a cytochrome P‐450 was observed only in other strains of Acinetobacter.

A. calcoaceticus69/V contains a particulate pyridine nucleotide‐independent and a soluble NADP‐dependent alcohol dehydrogenase; the particulate aldehyde dehydrogenase is also NADP‐dependent. The particulate dehydrogenases are inducible.

The results concerning the regulation of enzymes of the citrate and glyoxylate cycle as well as of the malic enzyme indicate that the corresponding fatty acids formed from the alkanes are metabolized via β‐oxidation.
Regulation der fettsäurebildung bei der mikrobiellen alkanoxidation
Authors: Rehm H. J. , Hortmann L. , Reiff I.
Published: December 2004

At the microbial oxidation of long‐chain alkanes such monocarbonic acids at a monoterminal oxidation are formed which correspond to the chain length of the alkanes. At diterminal oxidation the corresponding dioic acids are produced.

Under the influence of cerulenin a cerulenin a direct incorporation of fatty acids into cell lipids increases. Undecanoic acid cannot be metabolized byMortierella isabellina. It causes an inhibition of alkane oxidation. A main effect of undecanoic acid is an inhibition of the elongation of other fatty acids. The de novo fatty acid biosynthesis has not been inhibited by undecanoic acid.
β‐1, 3‐Glucanase from trichoderma viride. Purification and characterization
Authors: Merc M. , Galas E.
Published: December 2004

The extracellular complex of β‐glucanases produced by the mould Trichoderma viride hydrolyzes β‐1,3‐; β‐1,4‐ and β‐1, 6‐bonds of β‐glucans, as well as mixed β‐1,3‐ and β‐1,4‐glycosidic linkages. This complex contains also xylanase. The enzymes were isolated from liquid culture medium by centrifuge techniques, concentration and precipitation with acetone. Isolation and purification of β‐1,3‐glucanase was carried out according to a procedure involving filtration on Bio‐Gel P‐100, DEAE‐Sephadex A 50 and CM‐cellulose C‐11 chromatography, ultrafiltration and selective adsorption on xylan. The homogeneity of the enzyme was determined by polyacrylamidegel electrophoresis. The purified homogeneous preparation of the isolated β‐1,3‐glucanase from Tr. riride was subjected to detailed characterization. Amino acid composition, molecular weight and optimum conditions for the enzymatic activity of the protein were determined. The isolated enzyme was shown to be highly specific to substrates with β‐1,3‐glycosidic linkages; the rate of degradation was found to be proportional to the degree of polymerization of the substrate.
Rechnergestützte Führung von Fermentationsprozessen, Teil 2
Authors: Prause M. , Schulz H.‐J , Wagler D.
Published: December 2004

In the first part of the publication [1] an algorithm for the adaptation of the static optimum was represented. This part demonstrates the application of this algorithim to a specific problem. The problems, which are connected with the application of the choice of the object function, of making the process model available and of the realizable economic effects are elaborated.

The example of the tested on‐line control of a strirred tank reactor shows the advantages and disadvantages of the used algorithm.
Zur Maßstabsübertragung von aeroben mikrobiologischen Prozessen Teil II. Wärmetransport
Authors: Kudrewizki F.
Published: December 2004

An universal consideration is proposed for calculation of the heat exchange of industrial fermenters at which the energy‐intake is usual as main parameter in the formulas. On this way mathematical models developed, useful for heat transport during mixing by means of mixer with and without aeration, during boiling and for bubble column, are declared. With these models it is possible to describe Non‐Newtonian fluids, which rheological conditions in the concrete apparatus is formed by the intaken energy. Stable rubbers are proposed for treatment of high viscous fluids and a half‐empirical model is offered for its calculation.
Cultivation of mercury resistent microorganisms
Authors: Glombitza F. , Iske U. , Gwenner Chr.
Published: December 2004

A strain of bacteria was isolated from soil samples. The resistance of these microorganisms to mercury ions was proved by means of discontinuous and continuous fermentations.

Continuous fermentation was carried out also at a mercury ion concentration of 250 mg/l.

A balance of mercury distributions demonstrates the capability of these bacteria to accumulate a great amount of mercury.
Untersuchungen zur Anreicherung von Ubichinon‐9 aus Lipid‐Kohlenwasserstoff‐Fraktionen mittels Kurzwegdestillation
Authors: Voigt B. , Müller H. , Worbs M. , Winkler F. , Köhler U.
Published: December 2004

Short path distillation was used for the enrichment of 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. Phosphatides were isolated by extraction with acetone before distillation. The acetone soluble fraction was distilled by a pressure of ≦ 0.5 kPa and a temperature of 433 to 453 K. The concentration of the ubiquinone‐9 in the residue of distillation was three times higher than in the acetone soluble fraction.

Ubiquinone‐9 can be obtained by a simplified separation from the enriched fraction.
Untersuchungen zur enzymatischen Hydrolyse wasserlöslicher Celluosederivate im Hinblick auf die Bestimmung der Endo‐β‐1,4‐glucanase‐Aktivität
Authors: Polter E. , Kasulke U. , Philipp B.
Published: December 2004

Using as substrates various water‐soluble cellulose derivatives differing in DS and type of substituent, the efficiency of enzyme action in dependence of pH and the “CMC ase activity” of a Gliocladium spec. cellulase was investigated, stressing the significant role of effective charge density in connection with the results obtained with ionic derivatives of cellulose. From the results conclusions are drawn with regard to the proper choice of the substrate in determining CMC‐ase activity.
Der Respirationsfermentor – ein Labormeßsystem zur Charakterisierung aerober mikrobiologischer Reaktionen
Authors: Stottmeister U.
Published: December 2004

By use of a laboratory fermenter with a gastight circle aeration system all interesting values connected with the respiration of microorganisms can be determined.

The advantage of the respiration fermenter is the simple control of the oxygen partial pressure with high accuracy. The aeration is carried out by inert gas‐oxygen‐mixtures. This system was used to avoid errors in oxygen‐concentration measurement and regulation by oxygen sensitive sensors in fermentation fluids.

For each selected oxygen partial pressure in the course of fermentation the following date in connection with all desired analytical values can be determined by manual or automatical means.

Total oxygen consumption, momentary oxygen consumption rate, kinetics of oxygen consumption rate, kinetics of respiratory quotient.

Several opportunities of measurement are presented and examples for application in various microbial systems are given.
Investigation of α‐amylase and proteinase of culture filtrate from bacillus licheniformis MB 80 strain
Authors: Dobreva E. , Emanuilova E. , Kosturkova P. , Beschkov M.
Published: December 2004

At the investigation of some properties of the α‐amylase and proteinase in the culture filtrat from Bacillus licheniformis MB 80 strain it has been established that the α‐amylase activity is the highest at pH 6.0 to 6.5 and at 90°C, that the proteolytic activity is the highest at pH 9.5 to 10.0 and at 70°C and that the proteinase is inactivated at temperatures over 70°C.
Anreicherung eines Hefezellwand‐lysierenden Enzymgemisches aus Arthrobacter GJM‐1
Authors: Bieber J. , May R.
Published: December 2004

Two methods were employed in order to concentrate a large volume of an extracellular enzyme mixture for lysis of yeast cell walls: ultra‐short‐time evaporation and ultrafiltration. In the case of ultra‐short‐time evaporation there was a loss of activity by temperature while by ultrafiltration a good concentration could be received.
The effect of automatic ph maintenance on steady state cultivation regimes and their stability. A theoretical study of the case of a perfect ph controller and perfect stirring
Authors: Minkevich I. G.
Published: December 2004

The dynamics of pH‐controlled chemostat and pH‐auxostat is considered. The medium flow governed by pH‐controller is calculated using the ionic (mass‐charge) balance equations. The generalized equations of pH‐controlled continuous fermentation are developed for the case of two variables: cell biomass and residual substrate concentrations. The study of steady state solutions has shown a substantial dependence of the variable patterns on a concentration of alkali (or acid) in titrant medium flow. The generalized analytical expressions for eigenvalues (reciprocals of transient characteristic times) of the culture dynamics have been obtained. The rates of transients during the steady state establishment are considered using these eigenvalues.
Silierung durch aerobe Säuerung – paradoxer Einfall oder praktische lösung?
Authors: Sattler K. , Babel W.
Published: December 2004

For ensiling of herbage which is rich in protein and therefore difficult to ferment a procedure is proposed. It is based on aerobic acidification using biological deoxydants. The crops are treated with a suspension of living cells of Acetobacter methanolicus and a water solution of ethanol. This treatment brings about environmental conditions which promote lactic acid fermentation: anaerobiosis, complex nutritional supply and protective concentrations of H+‐ions. Preliminary attempts have confirmed the principle of conservation by aerobic acidification combined with biological deoxydation in agricultural practice. Damages of legume crops with high protein content are prevented. The advantages of the new ensiling process is discussed in comparison to traditional treatment.
Renaissance der Oberflächenkultur: Produktion von Mutterkornalkaloiden und Sporenbildung
Authors: Kybal J. , Sikyta B.
Published: December 2004

Industrially acceptable production of ergot alkaloids in surface culture under sterile conditions is described. After elucidation of the biochemical and morphological differentiation in the production microorganisms it is possible to elaborate a relatively simple cultivation method with good yields. Surface cultivation is especially advantageous for the production of spores in large quantities which are used as inoculum in industrial fermentations or as infection material (field production of ergot alkaloids, mycoinsecticides).
Optimization of solid‐state fermentation of citrus dried peel by aspergillus niger in a packed bed column
Authors: Rodriguez J. A. , Bechstedt W. , Echevarria J. , Sierra N. , Delgado G. , Daniel A. , Martinez O.
Published: December 2004

The protein enrichment of citrus dried peel on solid‐state fermentation by Aspergillus niger in packed bed column was optimized using a two factor central composit design with α = 2 considering the “initial moisture content of the fermentation mass” and the “temperature in the centre of the fermenter”. It results significance for the moisture content (optimum 56%) and non significance for the temperature in the conditions employed. This indicates that a considerable range of temperature increase for the investigated SSF system could be allowed.
Theoretische Grundlagen des Auxiliarsubstratkonzeptes und seine praktischen Konsequenzen in biotechnischen Prozessen
Authors: Babel W.
Published: December 2004

Raw materials for microbial synthesis of single cell protein and metabolites are chemo‐heterotrophic substrates. The growth and product yields are economically very important parameters. Therefore it is necessary to look for methods to optimize these biotechnological processes, i. e. to increase these values up to the theoretically possible limits.

In the SCP production the growth yield is determined energetically and in the overflow production the yield is influenced by the amount of biologically useful energy which is produced during the product synthesis.

It is demonstrated that the auxiliary substrate concept is appropriate to improving the yield both for SCP‐ und product synthesis.

In the SCP synthesis two (or more than two) substrates must be mixed that way that the biologically useful energy, which is generated along the way from substrates to a central precusor for the cell substance synthesis, becomes a maximum thus no further substrate need to be oxidized merely for the purpose of energy generation.

By using a substrate, which operates only as an energy donor in the mixture the carbon metabolism determined upper limit of the carbon conversion efficiency can be attained.

For with the overflow production of metabolites the biologically useful energy seems to be responsible for the discrepancy between the metabolism‐determined product yield and the experimentally obtained one, the energy liberated during the production of primary metabolites must be kept low.

This might be reached by using substrate mixtures.

Furthermore it is shown that in this way the specific production rate can be improved as well.
Anreicherung von Cadmium in Biomassen
Authors: Gwenner Chr. , Wittig H. , Glombitza F.
Published: December 2004

The uptake of cadmium ions from an aqueous solution by living, resting, and dead biomasses was investigated. The dependence of the uptaked amounts on pH‐value of the medium, temperature and concentration of cadmium ions is demonstrated as well as the rate of uptake.

Maximum realisable concentrations were 12 mg/g biomass in living cells and about 20 mg/g biomass in resting or dead cells, respectively.
Exogenous cellulases of thermophilic micromycetes. II. Thermostability of enzyme preparations
Authors: Kvesitadze G. , Gogilashvili L. , Svanidze R. , Buachidze T. , Chirgadze L. , Nizharadze D.
Published: December 2004

The ability of a large number of higher fungi to form extracellular cellulases is investigated. Some representatives of these fungi grow at 40–50°C, and form extracellular cellulases exceeding cellulases of mesophilic fungi in thermostability. It is shown that cellulases of higher thermophilic fungi differ by their thermostability. The temperature optimum of cellulase action of higher fungi occurs within 60–62°C.
Oil feeding during the oxytetracycline biosynthesis
Authors: Ettler P.
Published: December 2004

The ability of utilization of vegetal oils belongs to common properties of Streptomycetes. During the cultivation of Streptomyces rimosus and biosynthesis of oxytetracycline in 15 m3 fermenters, a fixed regime of soya bean oil feeds as antifoam agent and partial carbon source according to subjectively designed mechanism was investigated and further also feeding regime after exhausting starch as main carbon source and finally his dosing with ammonia sulphate in accordance with physiological activity of the culture. In the second case with semicontinuous supplements of soya bean oil it was possible to prevent premature autolysis of mycelia and to extend the biosynthetic process with keeping the oxytetracycline production rate. The third approach, the most progressive one, represents besides the automatisation of control loop the necessity of assurance continuous pH adjustment for elevation of the process production rate.
Studies on biosynthesis of hydrolases by trichoderma sp. M7 on submerged and solid‐state cultivation conditions
Authors: Atev A. P. , Panayotov Ch. A. , Bobareva L. G. , Damyanova L. D. , Nicolova U. D.
Published: December 2004

The biosynthesis of cellulases and xylanase by the mould strain Trichoderma sp. M7 on submerged and solid‐state cultivation conditions has been studied. The effect of different inducers on the enzyme biosynthesis on the conditions used was determined. The relation between the enzyme biosynthesis and the morphological state of the producing strain was studied. The advantages of the submerged cultivation conditions with regards to the efficiency of the enzyme inducer are shown.
Selection of distiller's yeasts with particular respect to non‐saccharomyces strains
Authors: Laube K. , Wesenberg J. , Lietz P.
Published: December 2004

The investigations demonstrate that in addition to Saccharomyces also strains Candida and Hansenula can be used for ethanol production. Their efficiences are at the standard level and the first phase of fermentation is considerably accelerated with results in suppression of bacterial contamination in cold mashing. In the future efficiency optimisations will be expected based on mixed strain populations as well as on technological improvement. Furthermore, genetic modifications present actually a real prospect to secure “made‐to‐measure” strains for special processes of corn mash fermentation.
Comparative trace element and organic growth factor requirements of five hansenula species
Authors: Kamra N. , Madan M.
Published: December 2004

A comparative response of specific trace elements and organic growth factors for the growth of five Hansenula species (H. anomala, H. beijerinckii, H. ciferrii, H. polymorpha and H. sydowiorum) has been studied. Out of twenty three trace elements tested, Fe, Zn, Mn and Cu were found to be essential for the growth of all yeast species studied here, whereas the rest of the elements exhibited variable essentiality. From fifteen organic growth factors tested, thiamine, biotin, pyridoxine and inositol are the most commonly required growth factors by the yeasts, whereas the rest of the organic growth factors showed variable essentiality. All species of yeasts investigated required different concentrations of trace elements and organic growth factors for their optimum growth. Concentrations higher than the optimum have been found to be inhibitory for the growth of all the yeasts studied.
State‐structure models of microbial growth
Authors: Bley Th.
Published: December 2004

A framework for modelling microbial growth is given in which the biological properties of the regulation of cell growth and proliferation are taken as a basis. Some stages on the way of formulating state‐structure models are discussed. The resulting delay‐differential equations are both comprehensible and suitable for a mathematical treatment.
Einfluß von Lipidfraktionen mikrobieller Herkunft auf die Wasserausnutzung in der biologissechen Stoffproduktion von Kulturpflanzen
Authors: Bergmann H. , Voigt B. , Seidel H. , Meisgeier G.
Published: December 2004

Effects of exogenous applied lipids being of microbial origin on the water use efficiency (WUE) and the biomass production have been studied in pot and field experiments using crop plants.

Lipid mixtures extracted from the cells of Candida maltosa EH 15 increased the WUE (9…16%) and the grain yield (÷x = 10%) of the wheat and barley plants under dry conditions. The fatty acid fraction separated from the lipid mixtures also improved the WUE especially under stress (20…100%) and the biomass production. The phosphatide fraction emulsified with sulfonate containing solvents was not physiologically active.
Optimal situation control for a biosynthetic process on the basis of a prediction filter
Authors: Möckel B. , Böhme B. , Bley Th.
Published: December 2004

A concept for the periodic control of fermentation processes is presented which realizes a strategy with maximal material and energetic efficiencies. The program system for situation control, problems of selection of the feature vector and the experimental results are discussed.
Rolle der n‐Alkane in Melasse‐Nährmedium beim Oberflächenverfahren der Citronensäurefermentation
Authors: Żzakowska Z. , Druri M.
Published: December 2004

The investigation of unfitness of beet molasses for citric acid production shows the presence of hydroacarbons in a toxic fraction of lipid extracts derived from antifoaming agents used in the suger industry. The model experiments demonstrate that these compounds dispersed in water solutions of the medium create on the surface of growing spores a layer which isolates them from the surrounding and prevents their normal growth. The inhibition effect of hydrocarbons on Aspergillus niger increases with degree of their dispersion in the water phase and is promoted by surface active substances e.g. emulgators present in antifoaming additives.
Use of heterotrophic microorganisms in mineral biotechnology
Authors: Groudev S. N.
Published: December 2004

A process for biological removal of iron from quartz sands, kaolins and clays was developed in which these industrial minerals were leached at 90°C with lixiviant produced as a result of the cultivation of acid‐producing heterotrophic microorganisms, mainly strains of Aspergillus niger, at 30°C in a nutrient medium containing molasses as a source of carbon and energy. The lixiviant, i.e. the fermentation fluid, contained oxalic and citric acids as main components and after the cultivation was acidified to a pH of 0.5 by means of hydrochloric acid. The leaching was carried out in mechanically stirred acid‐resistant vats for a period of from 1 to 5 hours. The iron content of some sands treated by this method was lowered from 0.035–0.088 to below 0.012% Fe2O3 making them suitable for the preparation of high quality glass. The iron content of different kaolins was lowered from 0.65–1.49 to 0.44–0.75% Fe2O3 and as a result of this their whiteness was increased from 55–87 to 86–92%. The iron content of a clay was lowered from 6.25 to 1.85% Fe2O3 and this increased the fireproofness of the clay from 1 670 to 1 750°C. Similar process was used for leaching of aluminium from aluminosilicates, mainly clays and kaolins. However, after the cultivation the fermentation fluid was acidified either by means of sulfuric or hydrochloric acid or by means of different mixtures of inorganic acids. For enhancing aluminium solubilization the aluminosilicates were heated before leaching at 600–650°C for 1–2 hours. Over 90% of the aluminium present in different clays and kaolins was leached within 3–6 hours in this way.

“Silicate” bacteria related to the species Bacillus circulans and B. mucilaginosus were used to leach silicon from low‐grade bauxite ores containing aluminosilicates as impurities. The bacterial action was connected with the formation of mucilaginous capsules consisting of expolysaccharides. The solid residues after leaching were characterized by higher values of alumina content and were suitable for processing by means of the BAYERprocess for recovering aluminium.

Heterotrophic bacteria were used to leach manganese from oxide ores using different organic compounds as reducing agents.
Gasometric measurement of sulfite oxidation
Authors: Nikolajewski H. E. , Liepert H.
Published: December 2004

In the commonly used sulfite method the consumption of sulfite is determined by iodometry. Since however, the addition of organic substances may interfere with iodometry (e.g. due to chemical reactions with iodine) the gasometric measurement of sulfite oxidation has been developed for analysis of how different culture media may influence the oxygen transfer rate. The striking decrease of sulfite oxidation rate due to addition of culture media to the sulfite solution suggests that adsorption of orgnic components in the gas liquid interface may account for an additional diffusion barrier and thus for a decrease of the oxygen transfer coefficient which in addition gives an explanation for differences between values found by the sulfite method and by aerobic cultivations. Consequently identical values of oxygen transfer rate have been obtained for both systems whenever the sulfite system has been properly adjusted to the aerobic cultivation conditions. In so far, the gasometric sulfite method proved to be a unique tool for rapid determination of factors influencing oxygen transfer rate in fermentation processes which may give rise to a reappraisal as to the relevance of the sulfite method for oxygen transfer optimization.
Enzymelektrode zur Bestimmung von L‐Lysin in Aminosäuregemischen
Authors: Weissbach F. , Schindler W. , Huber J. , Kreibich G.
Published: December 2004

A specific enzyme electrode with L‐Lysine decarboxylase (E.C. 4.1.1.18) from Klebsiella pneumoniae and a CO2‐sensor are described. The electrode can be used for assay of L‐Lysine in amino acid mixtures as protein hydrolysates or culture filtrates from fermentation processes. The accuracy and reproducibility are those of an amino acid analyzer. The electrode works well for several weeks.
Laugung lateritischer Nickelerze mit heterotrophen Mikroorganismen
Authors: Bosecker K.
Published: December 2004

Organic acids that are excreted by microorganisms dissolve nickel from lateritic ores. In chemical leaching experiments, fifteen organic acids were tested in the concentration range of 0.05–0.5 M. The most effective were hydroxycarboxylic acids. The leaching of nickel is dependent on the type of mineralization. With completely limonitized ore, no mobilization occurred, while up to 90% of the nickel was extracted from silicate‐bearing laterites by 0.5 M citric acid.

In biological leaching tests, Penicillium was found to be the most effective microorganism. After improvement of the leaching conditions, up to 70% of the nickel was extracted at considerably lower citric acid concentrations than with the chemical leaching process. Generally, leaching of nickel from lateritic ores with heterotrophic microorganisms is possible and seems to be promising. Possibilities for future investigations are discussed.
Induction of cellulase in trichoderma reesei grown on lactose
Authors: Farkaš V. , Šesták S. , Grešíak M. , Kolarova N. , Labudová I. , Baucer Š.
Published: December 2004

Intracellular concentrations of ATP, cyclic AMP and glucose‐6‐phosphate were monitored during growth of partially catabolically derepressed strain of Trichoderma reesei CC II in medium containing lactose as the sole carbon source. The induction of cellulase synthesis occured when the concentration of lactose in the medium decreased below 7 mg/ml. The onset of cellulase synthesis was preceded by a transient peak of intracellular concentration of ATP and by the increase of the cyclic AMP contents in the mycelium whereby the intracellular level of glucose‐6‐phosphate was at its minimum. By keeping the lactose concentration in the medium at 2 mg/ml, it was possible to support the continuation of cellulase synthesis over the prolonged periods without appreciable growth of biomass.
Verbesserung alter biotechnologischer Verfahren
Authors: Schügerl K.
Published: December 2004

By the example of the Penicillin G production, it is shown, how the production process can be improved by using pellet suspension instead of highly viscous filamentous mycel. In order to optimize the pellet geometry, dissolved oxygen concentration profiles were measured, and the overall mass transfer resistance was calculated in the pellets; histological investigations were carried out with pellets also. All measurements indicated that the optimal pellet diameter is 400 μm. When using this pellet, the specific power input was reduced from 4–5 kW/m3 to 0.8 kW/m3. The losses during the recovery of Penicillin G can be reduced below 1% by using reactive extraction. The thermodynamics, kinetics and reaction technique of reactive extraction of Penicillin G are also taken into account.
Nutzung cellulosehaltiger Abprodukte bei der Biosynthese von Cellulasen
Authors: Pobedimskij D. G. , Mukmenev I. E. , Savdur V. I. , Liakumovic A. G. , Agadganjan S. I.
Published: December 2004

It was analysed the influence of different pretreatment methods of cellulosic materials to increase the productivity of the cellulase biosynthesis.

The most effective pretreatment method for cotton cellulose is the thermomechanical destruction in a worm extruder (5–15 minutes) with hydrolysis catalysts.

The enzymatic saccharification degree was increased about 4 fold. Utilizing a pretreated cellulose an increase of 70–120% in C1‐activity was found besides their level was stabilized in higher values.

It was demonstrated that enzymatic hydrolysis parameters would be applied as model for biochemical utilization of cellulosic materials in the biosynthesis of cellulases.
Biotechnologische Produktion mikrobieller Wirkstoffe: ein Beispiel für die Nutzung des Adaptationspotentials von Mikroorganismen
Authors: Gräufe U.
Published: December 2004

The role of the microbial secondary metabolism in the cytodifferentiation of producer strains and in the ecological system is reviewed. The production of bioactive metabolites such as antibiotics seems to play a role in long‐term strategies of adaptation to environmental changes. This is reflected by characteristic features of regulation of the secondary metabolism such as catabolite repression, lack of uniform regulatory mechanisms and limited specificity of enzymes involved. The examples given may show that advantages have been taken from the knowledge of special regulatory features with regard to strain improvement and the designing of the metabolite spectrum.
Effects of temperature on microbial ethanol production. III. The influence of the temperature on the relation existing between the specific ethanol formation rate of the yeast Saccharomyces cerevisiae Sc 5 and the ethanol concentration in the culture medium
Authors: Richter K. , Becker U.
Published: December 2004

The ethanol‐inhibitory behaviour of the yeast Saccharomyces cerevisiae Sc 5 was found to be characterized by a continual‐linear relation between the specific ethanol formation rate and the ethanol concentration. Therefore the simple equation

could be applied for it.

It is shown that this model is correct only then, if all of the process parameters are in their optimum.

Out of the optimum temperature range the characteristics of the function ν = f(P) change in such a way that in regard to the ethanol concentration P twc linear relations exist for each suboptimum temperature:

and a non‐linear equation is current for each superoptimum temperature:

where bT is also a function of the temperature and always less than 1.

Taking as a basis these equations the specific ethanol formation rate of the used strain can be calculated for the whole biokinetic P/T‐sphere of ethanol production.
Production of ethanol from cassava whey
Authors: Akpan I. , Uraih N. , Obuekwe C. O. , Ikenebomeh M. J.
Published: December 2004

Investigations were conducted into the potential use of enzyme hydrolysed cassava whey for ethanol production by Saccharomyces cerevisiae Aspergillus niger grown on whct bran was used as crude enzyme source to saccharify the whey starch. The whey with an initial HCN concentration of 54.0μg/ml was fermented at pH 4.5 and 30°C in a one‐step process to produce ethanol. A maximum ethanol concentration of 4.5% (v/v) was obtained in 120 h with a decrease in HCN level to 4.0 μg/ml. In a two‐stage fermentation, in which the raw whey was pre‐hydrolysed and under the same fermentation conditions, the unsterilized hydrolysate yielded alcohol content of 5.5% (v/v), while the sterilized hydrolysate gave higher alcohol yield, 7.5% (v/v), in 48 h. No HCN was detected in the fermented liquour at the end of the two‐stage process.
Acid‐base solar biobattery exploiting water plants
Authors: Nešspůrková L. , Rybová R. , Janáčcek K.
Published: December 2004

A biobattery of a new type in which pH difference between two media serves as a source of free energy is described. The ability of some algae and other water plants to change markedly the pH of their surroundings according to the light conditions can be used to maintain two solutions at widely differing pH values. Electrical energy may be obtained from this source as a by‐product to biomass production.
Growth kinetics of top and bottom cultures of Saccharomyces spp. in a chemostat using sugarbeet molasses
Authors: Alexander D. B. , Zajic J. E. , Jones L. P.
Published: December 2004

Growth kinetics were evaluated for three yeast strains of the genus Saccharomyces. Two topfloating strains, SF 115 and SF 116 and one flocculant yeast SF 104 were analyzed in pure and mixed cultures in 1‐liter continuous fermentation experiments in a chemostat. Growth was monitored for 72 h at 30°C in a medium containing sugarbeet molasses and 1.0 g/liter each of NH4H2PO4 and urea. SF 115 and SF 116 were found to have lower μmax values of 0.290 and 0.296 h−1, respectively, than SF 104, which had a μmax of 0.364 h−1. The two top‐floating yeasts (SF 115 and SF 116) demonstrated greater affinity for the substrate and utilized substrates at a greater rate. They have K8 values of 4.03 × 10−3 M and 3.798 × 10−3 M, respectively, compared to 9.06 × 10−3 M for SF 104. A mixed culture of SF 116 and SF and SF 104 was found to have a μmax of 0.426 h−1 with a Ks of 6.924 × 10−3 M. SF 115 grown in mixed culture with SF 104 exhibited a μmax of 0.473 h−1 with a Ks of 7.975 × 10−3 M. In both cases, the SF 104 was the dominant microbe in mixed culture systems.
Untersuchungen zur gelpermeationschromatographischen Fraktionierung von Natrium‐Ligninsulfonat
Authors: Polter E.
Published: December 2004

The gelpermeation chromatography of sodium ligncsulfonates with bidistilled water as an eluent is influenced by the volume expansion of the polyelectrolyte, by the negative changes of the gels, and by the inclusion effect so markedly that true conclusions on the molecular weight distribution of sodium lignosulfonate cannot be drawn. Using electrolytes as an eluent these irregularities can be avoided. Polydispersity of these macromolecules however prevents separation into discrete peaks. As a result of this behaviour changes of molecular weight distribution are only poorly recognized. Therefore, on studying biotransformation of lignosulfonic acids we purpose to use gels by which one part of the lignosulfonates is excluded, and biotransformation may be controlled by the ratio of excluded part of the lignosulfonates to that part retarded by the gels.
Simultaneous utilization of methanol and glucose by Hansenula polymorpha (Torulopsis sp.) MH 26, a chemostatic investigation on the distribution of 14C‐methanol
Authors: Müler R. H. , Babel W. , Uhlenhut G. J.
Published: December 2004

Simultaneous utilization of methanol and glucose by Hansenula polymorpha (Torulopsis sp.) MH 26 results in an increase in growth yield of up to 18% in dependence of the mixing proportion. The distribution of carbon from 14C‐methanol into biomass and carbon dioxide was investigated. The distribution pattern was strongly influenced by the mixing proportion showing that methanol plays an increasing role as an energy donor as the glucose content in the mixture increased. Due to these data and verified by theoretical considerations the effect on growth yield was discussed to be caused by an interconnection in the conversion of the individual substrates. This is attributed to glucose delivering the acceptor for C1‐assimilation and resulting in a more efficient utilization of glucose carbon on the one as well as the energy content of methanol on the other hand.
Enrichment of soybean milk with calcium
Authors: Prabharaksa Ch. , Olek A. C. , Steinkraus K. H.
Published: December 2004

Calcium in soymilk was increased to that of human milk by the addition of 0.2% calcium lactate. It was, however, impossible to raise the calcium content of soymilk to that of cow's milk. The maximum amount of calcium lactate that could be added to soymilk without coagulation of the milk protein was found to be 0.45% which resulted in about 75 mg of Ca/100 ml of soymilk. This amount was approximately 60% of the calcium in cow's milk. Sodium citrate had to be added in combination with calcium lactate to reinforce colloidal stability of the milk. The ratio of Ca to P in the milk containing added 0.45% calcium lactate was comparable to that of cow's milk and at the amount normally consumed daily by infants and children it seemed to meet the requirements of Ca and P.
Optimization of single cell protein production from cassava starch (Rhizopus oligosporus)
Authors: Sukara E. , Doelle H. W.
Published: December 2004

The fermentation pattern of cassava starch utilization was investigated at 37°C using Rhizopus oligosporus UQM 145 F and eight different media. Depending on the medium used, the addition of zinc or zinc plus iron to a combination of calcium plus manganese switches the fermentation from glucose accumulation to biomass (single cell protein) production. Complete starch hydrolyzation was obtained in both cases, with a complete glucose utilization resulting in 24 g biomass containing 30% true protein per 100 g cassava starch (= 7.45 g SCP/100 g substrate) in 24 hours. In the case of glucose accumulation, biomass was kept low and 15.5 g/l glucose representing 57.3% of starch supplied were obtained in 36 hours. R. oligosporus UQM 145 F grows well between 30° and 45°C. At 45°C and pH 5.0, 7.0 g SCP/100 g substrate were obtained, which rose to 8.6 g if cassava starch is replaced by ground cassava tuber.