bluuebunny/crossref_metadata_2025_split huggingface dataset:
High‐performance fermentation with lactic acid bacteria entrapped in pectate gel. Immobilizates with enhanced lactate formation activity
Authors: Richter K. , Rühlemann I. , Berger R. 
Published: December 2004

AbstractHigh‐loaded pectate gels containing more than 1014 cells/l of gel (viability > 60%) were obtained. Immobbilizates of Lactobacillus sp. IMET 11466 showed a maximum mean gel activity of 120 g of lactate/l of gel * h. With the strain Streptococcus thermophilus Č 129 a value of 139 g of lactate/l of gel * h was attained. Using these immobilizates the conversion of 100 g of glucose/l with a yield of 90–95% can be realized in only 6–8 h. On the basis of a detailed analysis of the time course of the lactate‐forming activity of the immobilizates during batch fermentations evidence is given of an analogy in the lactate‐inhibitory behaviour of immobilized and free cells.
Antigen‐specific enrichment of peripheral blood lymphocytes with magnetic beads combined with electrofusion enables efficient production of human mabs
Authors: Glaser R. W. , Seifert M. , Hungerer K.‐D , von Baehr R. 
Published: December 2004

AbstractThe low incidence of antigen‐specific B cells in available material is one of the major problems in human monoclonal antibody production. A technique is described which permits the efficient production of specific hybridomas by the separation of specific B cells with magnetic beads prior to fusion.Cells with immunoglobulin γ chains on the surface were enriched from human peripheral blood lymphocytes by separation withmagnetic beads. After electrofusion of the pre‐enriched fraction with CB‐F7 heteromyeloma cells, the percentage of IgG‐producing hybridomas was considerably enhanced. Similarly, B cells with antigen‐receptors for α haemolysin from Staphylococcus aureus were enriched by separation with antigen‐coated beads. In nine fusion experiments taken together, 153 out of 503 wells contained antigen‐specific immunoglobulin after the application of this technique, compared with 37 out of 1584 wells after immortalization of unseparated lymphocytes. The ratio of IgG:IgM‐producing antigen‐specific hybridomas was slightly shifted towards IgM.Using this technique, antigen‐specific hybridomas from lymphocytes of healthy normal donors were established without any artificial administration of antigen.
Spectrophotometric study of green microalgae biomass color
Authors: Sokolov K. , Devenski P. 
Published: December 2004

AbstractIt has been found visually and by spectrophotometric measurements that the infection of the algae culture of Sc. acuminatus used for biomass production has caused a changing of its color toward the large wavelengths of the spectrum. Experimental studies have proved that the color change was due to the reaction between the phytoplankton and the nitrous acid produced throughout the cultivation process. It has also been demonstrated that the coefficient of bathochromicy introduced in this study was efficient for quantitative estimation of algae biomass color, and could be used for control of algae culture color.
A contribution to the mechanical disrupture of microorganisms on a small technical scale
Authors: Luther H. , Schuster E. 
Published: December 2004

AbstractThe mechanical disrupture is described with the examples of selected yeasts, fungi and bacteria under practical circumstances. A particularly high degree of disrupture while simultaneously avoiding a strong destruction of the cell wall, and a trouble‐free continuous are operation are considered.With the aid of laboratory studies and the physicochemical data of the biomass, suitable equipment for the small technical and industrial scale can be chosen.
Application of flocculation for extracellular proteinases recovery
Authors: Sitkey V. , Kuzmová E. , Horenitzký R. , Michalík P. , Minárik M. 
Published: December 2004

AbstractThe recovery of bacterial extracellular alkaline and neutral proteinases was investigated using mineral hydrocolloid bentonite in combination with the organic flocculant Hernostan B for the removal of solid compounds and cells from fermentation broth. The flocculation was effective in the pH range of 7.0–8.5 at concentrations of bentonite of 2.0–5.0 g · dm−3 and Hernostan B of 1.0–5.0 g · dm−3. The results show that, by means of this technique, it is possible to achieve a yield of proteinases above 90% on a laboratory, and up to 85% on a pilot plant scale.
Importance of invertase activity for gluconic acid production from sucrose by aspergillus niger
Authors: Rosenberg M. , Švitel J. , Rosenbergová I. , Šturdík E. 
Published: December 2004

AbstractThe excretion, cellular distribution and pH profiles of invertase in Aspergillus niger CCM 8004 were characterized. An optimized pH control was proposed for conversion of sucrose to gluconic acid and fructose: pH was maintained at 4.5 until the 12th hour and at 5.5 from the 12th hour of fermentation. 300 g · dm3 of sucrose was converted within 31 hours by this procedure.
Oats tempeh
Authors: Nowak J. 
Published: December 2004

AbstractOats was used as a substrate in tempeh fermentation. The time needed to obtain sufficient mold growth was at least 30 hours at 31°C (Rhizopus oligosporus NRRL 2710). pH was decreasing during the first 32 hours of incubation reaching pH = 5.30. Fermentation of oats led to an increase in water soluble nitrogen, but it did not change protein nitrogen content. R. oligosporus proteinases of optimum pH = 5.50 are postulated to play an important role in oats tempeh fermentation. When a mixture of oats and soybean (1:1) was used, mold growth was faster and the cake tougher. Mixing cereals with legumes to produce good tempeh is recommended.
Enzymes from thermophiles
Authors: Zentgraf B. 
Published: December 2004

AbstractThe most frequently used sources of more stable enzymes are thermophilic bacteria, e.g. Bacillus, Closrridium, and Therrnus strains, occurring in natural as well as man‐made habitats. They grow from 55 to 88°C with a specific growth rate of up to 2.6 h− and a yield coefficient of up to 0.4 gram of dry cell weight per gram of carbohydrate consumed. Several thermophilic strains, e.g. Bacillus sp. TP32, rapidly and effectively produce enzymes having a higher thermal stability and resistance to chemical denaturants in comparison to their mesophilic counterparts.Therefore, thermostable enzymes are of importance for bioorganic syntheses. For the further optimization of enzyme production, genetic engineering is applied.
Isolation of thermophilic bacteria similar to Thermus sp.
Authors: Zentgraf B. , Hedlich R. , Fiedler E. , Geyer W. , Uyen N. V. , Thao N. N. 
Published: December 2004

AbstractSeveral thermophilic strains similar to Thermus sp. were isolated from a hot spring in Nha Trang (Vietnam), and a domestic hot water reservoir, respectively. They grow aerobically on a complex medium at a temperature of 55 to 70°C and a pH value of 7 to 8. The cells are gram‐negative, non‐motile and non‐sporulating. They possess yellow or red pigments. The isolated strains are similar to Thermus sp. in regard to the composition of the intracellular fatty‐acid fraction as well as the absorption spectra of the extracted cellular pigments.
Effect of pea and soybean extracts on the growth of five clostridium strains
Authors: Nowak J. 
Published: December 2004

AbstractWater extracts of pea and soybean stimulated the growth of five tested gas‐producing Clostridium strains. When pea and soybean tempeh extracts were used the inhibition effect took place. It is postulated that an antibacterial compound is formed during tempeh fermentation. The stimulating effect might be connected with flatus formation by legumes.
Oxidative capacity determines the growth rate with Acetobacter methanolicus
Authors: Müller R. H. , Babel W. 
Published: December 2004

AbstractThe cultivation of Acetobacter methanolicus on various substrates revealed that the respective maximum growth rates are obtained at an almost identical oxidative capacity of about 16 mmoles of oxygen g (biomass)−1·h−1 under conditions of energy generations by complete substrate oxidation. This is considered to be an indication that the energy production rate determined by the capacity of the respiratory chain limits the growth rate in this strain. However, with glucose and glycerol, for example, a further increase in the growth rate is observed accompanied by the generation of products (gluconic acid or dihydroxyacetone, respectively). The incomplete oxidation should play the role of an additional energy generation. The potential for this rate increase is looked for in a higher energy gain derived from reduction equivalents (PQQH2) in this periplasmic oxidation step in relation to the cytoplasmic reduction equivalents.
Enzymatic hydrolysis of wheat straw: Kinetic analysis
Authors: Aguado J. , Romero M. D. , Moncó G. , Rodríguez L. 
Published: December 2004

AbstractPretreated wheat straw was enzymatically hydrolyzed in 250‐ml flasks using the culture filtrate of Trichoderma reesei QM‐9414. The influence of the initial enzymatic activity in the liquid phase was studied. The unreacted core model was used to analyze the experimental data obtained at 40, 46 and 50°C. The model adequately describes the data for hydrolysis times lower than 10 h.
Hemicellulolytic enzymes of the ligninolytic white‐rot fungus phlebia radiata. determination of enzyme activities
Authors: Rogalski J. , Hatakka A. , Longa B. , Leonowicz A. 
Published: December 2004

AbstractThe ligninolytic fungus Phlebia radiata growing in a low‐nitrogen medium, with wheat bran as the sole carbon source, produces a wide spectrum of hemicellulolytic enzymes. During the growth of the fungal culture, some properties of these enzymes were investigated.
Microbial protein from leguminous and non‐leguminous substrates
Authors: Sharma S. , Madan M. 
Published: December 2004

AbstractThe biodegradation of leguminous and non‐leguminous organic materials by Pleurotus sajor‐caju and P. ostreatus was studied. Comparisons were made between mushroom yield on both types of substrates. The conversion percentage from dry substrate to fresh mushroom (biological efficiency) was determined. Mushrooms were analyzed for their protein content, carbohydrates, percentages of ash, fat content and crude fibre. The energy value of fruit bodies was computed. The yield obtained from leguminous substrates was significantly high as compared to that yield which was obtained from non‐leguminous substrates. The lowest yield of P. sajor caju (10 g ± 0.3 g) and P. ostreatus (6.5 g ± 1.2 g) was obtained using the Bougainuillea substrate and the highest one (519 g ± 16 g, P. sajor‐caju and 488 g ± 18 g, P. ostreatus) using nitrogen‐fixing leguminous Leucaena leucocepholea. The nitrogen content in fruit bodies was found to be higher with leguminous substrate than with non‐leguminous ones.
Optimization of gluconic acid synthesis by removing limitations and inhibitions
Authors: Pöhland H.‐D. , Schierz V. , Schumann R. 
Published: December 2004

AbstractThe optimization task was performed using the gluconic acid synthesis by the Acetobacter methanolicusMB 58 strain. The microorganisms were grown continuously on methanol as the growth substrate. After finishing the growth process by the deficiency of N and P, the gluconic acid synthesis was started by adding glucose. The synthesis process was performed continuously. The oxygen transfer rate depended on the gluconic acid concentration. During the growth process, the oxygen transfer rate reached a value of about 13 g O2 · kg−1 · h−1using a 30‐l glass fermenter equipped with a 6 blade stirrer and fully baffled. This rate declined to a value of between 2 and 5 g O2 · kg−1 · h−1 in the presence of gluconic acid concentrations above 150 g gluconic acid · kg−1medium. The yield (g gluconic acid · g−1glucose) depended on the gluconic acid concentration and amounted to y = 0.7 in relation to 150 g gluconic acid · kg−1medium and y = 0.8 in relation to 200 g · kg−1medium, respectively. The fermenters were coupled with ultrafiltration moduls (Fa. ROMICON and Fa. SARTORIUS). The biomass concentrations amounted from 5 to 40 g dry mass kg−1medium. The ultrafiltration modules retained the biomass within the fermentation system. A glucose solution (30 to 50 weight percent glucose) was continuously dosed into the fermenter. The retention time was chosen between 2 and 30 h. The gluconic acid synthesis rate reached values of up to 32 g gluconic acid · kg−1 · h−1. Within a range of up to 250 g gluconic acid · kg−1medium, the acid concentration had no influence on the enzyme activity.
Kinetics of the selective fermentation of glucose from glucose/fructose mixtures using Saccharomyces cerevisiae ATCC 36859
Authors: Koren D. W , Duvnjak Z. 
Published: December 2004

AbstractThe kinetics of batch fermentation during the growth of S. cerevisiae ATCC 36859 was studied in various glucose/fructose mixtures. It was found that the growth is inhibited equally by glucose and fructose even though fructose is not consumed to any large extent by the yeast under the conditions tested here. The inhibition of growth by the substrate and ethanol is represented by linear equations. These equations were combined with the MONOD expression in order to formulate equations for the biomass growth, glucose and fructose consumption and ethanol production. Parameter estimates were obtained by fitting these equations to batch fermentation data and so developing models which indicate that the growth is completely inhibited when 62 g/l ethanol is produced by the yeast, while glucose consumption and ethanol production continue up to an ethanol concentration of 152 g/l. Products containing a high concentration of fructose are best produced by using a high initial biomass concentration.
Characterization of transgenic mice lineages. I. Overexpression of hGH causes the formation of liver intranuclear pseudoinclusion bodies and renal and hepatic injury
Authors: Berlanga J. , Infante J. , Capó V. , de la Fuente J. , Castro F. O. 
Published: December 2004

AbstractThe expression of the human Growth Hormone (hGH) in transgenic mice is accompanied by health afflictions and structural changes in several organs and tissues. A macroscopic and light microscopic study was conducted to examine the morphological alterations related to the exposure of endogenously expressed hGH. Although many transgenic mice were under cachectic status, their body and organ weights were significantly higher than those of the controls matched. Kidney, liver and female genital organs were massively damaged.The most common findings in these organs were glomeruli hyalinosis and glomerulosclerosis in the kidneys accompanied by a varying degree of segmental sclerosis and necrosis. Tubuli dilatation was observed with hyaline casts and atrophied epithelium as well as interstitial fibrosis with mononuclear infiltrate. In the liver the hepatocytes were pleomorphic and exhibited vacuolar degeneration. Intranuclear lipid droplets were also found. Individual necrosis, mononuclear infiltrate and nuclear pseudoinclusions were also detected. The uterus exhibited cystic glandular hyperplasia and ovaries were observed to have several, large foamy cells as well as stromal infiltration of adipose cells. Other changes were found in the heart, the spleen and the salivary glands. A possible role of GH and/or the Insulin‐like Growth Factor‐I is suggested according to the morphological changes found. The similarity to kidney changes with human diabetic glomerulosclerosis was noticed.
Effects of trace elements on the growth of Phellinus pachypholeus pat.
Authors: Madan M. 
Published: December 2004

AbstractFifteen trace elements have been tested to determine the requirements for the growth of Phellinus pachypholeus Pat. The fungus requires in ppm, Fe: 10, Zn: 10–100, Mn: 1.0, Cu: 1.0, Mo: 1.0, B: 10.0–100. It does not require Ca, Pb, Br, I, Cr, Hg, W, Li or Cd. Concentrations higher than the optimum were progressively inhibitory for its growth.
Factors affecting the synthesis of penicillins by the immobilized penicillin acylase from Escherichia coli
Authors: Koteva K. P. , Ganchev K. D. 
Published: December 2004

AbstractThe effect of pH, temperature, reactant concentration, and reaction time has been investigated for the synthesis of N‐benzhydryl‐N′‐acetamidopiperazyl‐6‐penicillanic acid and N‐benzyl‐N′‐acetamidopiperazyl‐6‐penicillanic acid from 6‐aminopenicillanic acid by the immobilized penicillin acylase from Escherichia coli. The synthesis of penicillins from carboxylic acids proceeds most rapidly at pH 5; with ethyl ester derivatives of carboxylic acids the pH optimum is higher (6–7). The most rapid synthesis of penicillins was obtained with ethyl ester derivatives of carboxylic acids. The optimum temperatures were 25–35°C.
Isolation and analysis of the total genomic DNA from the date palm (P. dactylifera L.) and related species
Authors: Al‐Shayji Y. , Saleem M. , Al‐Amad S. , Al‐Awadhi S. , Al‐Salameen F. 
Published: December 2004

AbstractThe objective of this study was to adapt a plant DNA preparation procedure for the isolation of biologically active DNA and DNA with a high molecular weight from the date palm and other related palms. Mature leaf tissue extractions of the date palm, Phoenix dactylifera L., the coconut tree, Cocos nucifera, and the Mexican Fan Palm, Washingtonia robusta, were characterized for total genomic DNA yield, purity, integrity, as well as restriction digestion and ligation capabilities. It is demonstrated here that the DNA isolation procedure, modified for use with various palm leaf tissues, met the criteria for simplicity and low costs, and yielded DNA of high molecular weight (∼50 Kbp) and of sufficient purity suitable for molecular studies.
Diversity of PAH‐degrading bacteria in an airlift‐suspension reactor system for waste‐water cleaning
Authors: Maue G. , Dott W. , Kämpfer P. 
Published: December 2004

AbstractDifferent samples from a reactor system for the cleaning of an emulsified waste oil containing approximately 1% of different polycyclic aromatic hydrocarbons (PAH) were studied for the diversity of phenanthrene, anthracene, and acenaphthene‐metabolizing bacteria. From more than 28 different taxa found in the airlift‐suspension reactor, nine were able to mineralize at least one of the PAH, belonging to the genera Bacillus, Mycobacterium, Nocardia, Sphingomonas, Alcaligenes, Pseudomonas, and the Flavobacterium/Cytophaga group. In the sludge from the thickener of the reactor system, a reduced number of metabolically active groups could be detected. The impact of different precultivation substrates on the degradation capability was investigated with five PAH‐degrading bacterial strains. Four isolates were influenced by the precultivation substrates, however, one isolate (Alcaligenes‐like) as well as the mixture of the five strains showed no changes in their degradation capability. The results indicated a strong impact of the precultivation methods on the composition of bacterial communities and the activity and the degradation characteristics of bacteria with respect to different PAH.
L(+)‐Lactic acid from sweet sorghum by submerged and solid‐state fermentations
Authors: Richter K. , Träger A. 
Published: December 2004

AbstractSweet sorghum was used as the raw material for the lactate production by a strain of Lactobacillus paracasei. The submerged conversion of sugar juice obtained from sweet sorghum by extraction could be accomplished with the same efficiency as observed in a control experiment with MRS‐glucose medium (final lactate concentration of 88–106 g/l, lactate yield of 91–95%, duration of the fermentation of 24–32 h). Finely ground stalks of sorghum served as the substrate in the solid‐state fermentation. The lactate accumulation in the solid medium and the lactate yield were optimized up to values comparable with the results from the submerged fermentation (final lactate concentration of 90 g/kg, lactate yield of 91–95%). However, the duration of the fermentation amounted to 120–200 h in the solid‐state process. The data from a series of experiments performed at variable values of temperatures between 30°C and 36°C and initial sugar concentrations between 60 g/kg and 115 g/kg, and degrees of moisture between 78% and 82% was the basis of a polynomial multidimensional regression. As a result, simple three‐dimensional model functions were obtained for the maximum productivity of lactate formation, the lactate yield and the time required for a 90% conversion.
The properties of subtilisin, Novo type, immobilized on porous glass
Authors: Trzmiel T. , Fortak M. , Galas E. 
Published: December 2004

AbstractStudies of the properties of subtilisin, Novo type, immobilized on porous glass with the aid of hexamethylene diisocyanate were carried out. The immobilized proteinase preparation shows optimum activity at a pH value of 10.7 and at a temperature between 60–65°C. It was stable in a wider range of pH and temperature values than the native subtilisin. The KM values for hemoglobin and BAEE were 9.2 × 10−5 [M] and 139 × 10−5 [M], respectively. Under relatively non‐aqueous conditions, immobilised subtilisin was able to synthesize phenylacetic acid ethyl ester.
Whey disposal by deproteinization and fermentation
Authors: Kleine R. , Achenbach S. , Thoss S. 
Published: December 2004

AbstractThe non‐pollutant plant support material of the dwarf duckweed Wolffia arrhiza (Fam. Lemnaceae) was used for the entrapment of living yeast cells (Kluyveromyces fragilis) which hydrolyse lactose with the subsequent fermentation of glucose and galactose at high cell densities (up to 7.0 × 108/ml support). The stabile yeast‐plant cell immobilizates are able to produce ethanol from lactose‐containing media (e.g. whey) by batch fermentation (on a rotary shaker) or continuous fermentation (in a turbulence reactor) for several days (at a pH below 4.2 and a temperature of 30°C). The removal of whey proteins by a preceding heat denaturation of whey, high dilution rates, CSo values of 50 to 60 g lactose per litre whey and the preferential use of the K. fragilis strain DSM 7238 were determined as the prerequisites for an optimum continuous fermentation. Economically interesting productivities (Pmax ⩾ 15 g ethanol/1 · h, D = 0.72 h−1) with an actual lactose turnover of 90% were obtained by using these parameters.
Production of α‐glucosidase by Bacillus sp. strains
Authors: Castro G. R. , Baigori M. D. , Siñeriz F. 
Published: December 2004

Abstractα‐Glucosidase was detected in four wild‐type amylolytic strains belonging to the Bacillus genus. The strains showed α‐glucosidase activity in extracellular and membrane‐bound fractions. Kinitic studies of the α‐glucosidase synthesis in the batch cultures of four strains of the Bacillus genus showed two profiles: partially and totally growth‐linked synthesis.The presence of different activities and production profiles of α‐glucosidase in the strains at high or low glucose concentrations in the medium would indicate that α‐glucosidase may have a role in the regulation of the metabolism of α‐polysaccharides.