bluuebunny/crossref_metadata_2025_split huggingface dataset:
Cloning and Nucleotide Sequence Analysis of the Ampicillin Resistance Gene on a Conjugative R Plasmid from the Fish Pathogen Photobacterium damselae subsp. piscicida
Authors: Morii Hideaki , Bharadwaj Manish Surendra , Eto Naoya 
Published: December 2004

Abstract
Transferable resistance to various drugs was investigated in strains of Photobacterium damselae subsp. piscicida from Japan. Drug resistance was transferred via two plasmids of 100 and 50 kilobases (kb) or three plasmids of 100, 50, and 40 kb. Resistance to ampicillin was transferred on the 50-kb plasmid. An ampicillin resistance gene in the 50-kb plasmid pPDP8517 from strain PP8517 was cloned from a 1.8-kb Hinc II fragment of the plasmid. The nucleotide sequence of the coding and flanking region of the ampicillin resistance gene was determined to be 1,736 base pairs. The nucleotide sequence identified an open reading frame (ORF) encoding 282 amino acid residues with a calculated molecular mass of 31,292 daltons. The ampicillin resistance gene's ORF was found to be a β-lactamase bearing low levels of amino acid identities (&lt;63%) relative to other β-lactamases. This ORF was very high in amino acid identities with class A β-lactamases compared with those of class B, C, and D β-lactamases. Four important structural features were conserved in all class A β-lactamases present in the deduced amino acid sequence of the ampicillin resistance gene. These results suggest that the P. damselae subsp. piscicida ampicillin resistance gene is a class A β-lactamase encoded on an R plasmid that is distinctly different from other known β-lactamases. Moreover, Southern blot analysis suggested that P. damselae strains with the ampicillin resistance gene are widely distributed in marine fish farms in the Kyushu area in Japan.
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

Abstract
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

Abstract
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

Abstract
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

AbstractDie 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

AbstractA 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

AbstractMillet 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

AbstractA 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

AbstractBy 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

AbstractEnzymology 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

AbstractAt 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

AbstractThe 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

AbstractIn 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

AbstractAn 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

AbstractA 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

AbstractShort 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

AbstractUsing 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

AbstractBy 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

AbstractAt 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

AbstractTwo 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

AbstractThe 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

AbstractFor 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

AbstractIndustrially 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).