bluuebunny/crossref_metadata_2025 huggingface dataset:
Dihydrodipicolinate synthase of lysine excreting and non excreting strains of bacillus megaterium
Authors: Chatterjee M. , Chatterjee S. P. , Banerjee A. K.
Published: December 2004

Dihydrodipicolinate synthase activity of lysine producing strain of Bacillus megaterium and its high yielding mutant AECr 60f was highest during the end of the exponential phase and remained at the same level during the stationary phase when major bulk of lysine was accumulated. In comparision in a lysine non producing strain of B. megaterium the activity of the enzyme was low. Lysine producing strains has DHD synthase with two specialities, persistence during the stationary phase and insensitivity to repression by exogenous lysine. The high yielding mutant has increased DHD synthase activity which was not sensitive to feed back inhibition with lysine.
Characteristics of the immobilized pectin lyase activity from a commercial pectolytic enzyme preparation
Authors: Lozano P. , Manjón A. , Iborra J. L. , Gálvez D. M.
Published: December 2004

A commercial pectolytic enzyme preparation has been immobilized onto a nylon‐polyethyleneimine copolymer, in order ot study the contribution of the pectin lyase activity inthe overall pectindegrading activitg. Optimal conditions for the immobilization process of the pectin lyase activity, such as chemical modification of the support, coupling pH and protein concentration, were determined.

Kinetic parameters and temperature behaviour of both the soluble and immobilzied pectin lyase activitgy of the derivative were also determined. OPerational stability of the pectin lyase and overall viscosity reducring activities resulting in a halflife times of 3.8 and 8.5 days, respectively, for both pectolytic activities, when the immobilized derivatives were tested in a cross‐flow reactor, using a highly esterified pedtin as substrate.
Isolation and utilization of indigenous yeast strain for brewing of millet beer (OYOKPO)
Authors: Uraih N. , Anetekhai W. E.
Published: December 2004

Three yeast strains were isolated from a spontaneously fermented native millet (Pennisetum typhoideum) malt beer (Oyokpo). One of the yeast isolates found to have the most highly fermenting capacity was characterised and identified as a strain of Saccharomyces cerevisiae. The yeast was then utilised as the pitching yeast in a subsequent controlled fermentation of millet wort at 20°C for 120 hours. Bitter leaf (Vernonia amagdalina) extract was used as the bittering and flavouring agent. The Oyokpo beer sample produced under these conditions was found to possess both chemical and organoleptic qualities comparable to some extent, to the conventional barley malt beer. At the end of fermentation, the pH, specific gravity, alcohol content, reducing sugar content and protein content of the beer were 4.11, 1.0308, 2.81% (v/v), 4.00 (mg/ml) and 0.84 (mg/ml) respectively.
Biosynthesis of dehydroaltenusin by talaromyces flavus
Authors: Fuska J. , Proksa B. , Uhrían D. , Marvanová L. , Sturdiková M.
Published: December 2004

A new metabolite, identical with dehydroaltenusin was isolated from a strain Talaromyces flavus B 5 which was selected from parental strain 51 C/I. Metabolite inhibited the growth of wooddamaging fungi, especially Ciadosporium sphaerospermum and P388 leukemid cells.
Effect of trace elements upon the biomass production of some candida species
Authors: Madan M. , Kamra N.
Published: December 2004

Trace element studies were carried out on nine species of Candida. Out of twenty‐three trace elements tested, Fe, Zn, Mn and Cu were found to be essential for the growth of all the yeast species whereas the rest of the elements exhibited variable essentiality. All the species of yeasts investigated required different concentrations of trace elements for their optimum growth. Concentrations higher than the optimum have been found to be inhibitory for the growth of all the yeasts studied here.
Chemical and microbiological solubilization of silicates
Authors: Friedrich S. , Platonova N. P. , Karavaiko G. I. , Stichel E. , Glombitza F.
Published: December 2004

The solubilization of silicates was investigated using kaolin and quartz sand as model substances. The mineral solubilization was studied in the concentration of solubilized Si and Al. The chemical leaching of the silicates was carried out using inorganic and organic acids as well as sodium hydroxide. The process was more effective in the alkine than in the acid pH range. In the acid medium, oxalic acid showed maximum acidity and a tendency to form complex structures, especially with aluminium, and was most effective in leaching.

The microbiological influence on solubilization reactions was tested using a number of microorganisms among them acid, alkali and slime‐forming species. The highest leaching activity was observed in the case of Thiobacillus thiooxidans, whereas the heterotrophic microorganisms (among them Bacillus mucilaginosus) did not exercise a sollubilizing effect on the silicates.

X‐ray phase analysis of leached kaolin samples did not show any differences from the non‐leached mineral.
The use of plant cell vesicles for immobilization of yeast cells producing ethanol
Authors: Karbaum Ch. , Kleine R.
Published: December 2004

The preparation of immobilized living yeast cells adsorbed into or onto delipided specimens of the dwarf duckweed Wolffia arrhiza (Fam. Lemnaceae) is reported. These yeast cell‐plant cell conjugates were used for the repeated batch production of ethanol from glucose (143 to 246 g/l) or saccharose (150 g/l). Up to 25 fermentation cycles at 30°C were performed. The cycle time for complete substrate conversion to ethanol was reduced 10‐fold by a 5‐fold increase of the yeast cell Wolffia conjugate concentration (ε = 0.08 to ε =0.4) ε = volume of cell conjugate/totnl reaction volume. The corresponding ethanol production was 11.5 to 13.5 vol% and 9 vol% respectively. The reported results on the discontinuous ethanol fermentation with Wolffia‐immobilized yeast cells open the field for their application in continuous ethanol production processes.
The Influence of n‐[2‐isopentenyl] adenine on shoot differentiation in digitalis purpurea l. Tissue cultures
Authors: Čellárová E. , Hončariv R.
Published: December 2004

The morphogenetic capacity of Digitalis purpurea L. leaf explants and callus cultures has been studied. The promoting growth of calli was induced by the presence of exogenously applied auxins and cytokinins in the ratio 2:1. Bud and shoot differenatiation occurred in leaf explants and callus cultures of the 2nd subculture under the influence of 1.00 to 5.00 mg·1‐1 N67hyphen;[2‐Isopentenyl] adenine. The regeneration protocol described provides 7 to 10 plantlets per leaf explant. The results are compared with the effect of other cytokinins in Digitalis purpurea and a related Digitalis lanata species.
Continuous determination of protease during the fermentation using the autoanalyzer adm 300
Authors: v. Lupin I. , Körner D.
Published: December 2004

A method for automatic determination of proteolytic activity during fermentation is described. Therefore the autoanalyzer ADM 300 of the PRUEFGERAETEWERK MEDINGEN F.R.G. is connected to a fermenter. After filtration of the biomass, the culture filtrate is diluted and then incubated with casein solution. (0.75%, pH 8.0, 55°C) low moleculare cleavage products are separated from higher molecular ones by dialysis. The absorbence is measured at 600 nm after addition of alkaline copper tartrate and FOLIN solution. By use of different dilution rates, a range of 0–32 units ml−1 may be measured. The coefficient of variation is 5.5.
Unusual wax esters and glycolipids: Biocatalytical formation and physico‐chemical characterization
Authors: Lang S. , Multzsch R. , Passeri A. , Schmeichel A. , Steffen B. , Wagner F. , Hamann D. , Cammenga H. K.
Published: December 2004

By aid of lipases, e.g. of Mucor michei, in n‐hexane wax esters were produced from usual primary fatty alcohols and unusual hydroxy fatty acids (in part of microbial origin). Thus, (S)‐17‐hydroxyoctadecanoic acid dodecyl ester and (R)‐3‐hydroxy decanoic acid dodecyl ester were formed. In measurements of the film pressure using a LANGMUIR film balance the monolayers of both compounds indicated good stability compared to the non‐hydroxy wax esters. Glycolipids de novo produced by microorganisms did not show suitable wetting properties, but they were able to lower ze surface tension of water to a higher extent than the unusual waxes.
Effect of exogenous cycllc amp on catabolite repression of cellulase formation in aspergillus nidulans
Authors: Bagga P. S. , Sandhu D. K. , Sharma S.
Published: December 2004

The addition of 1 mM cyclic AMP to induced and repressed cultures of Aspergillus nidulans and its mutant strain (CRR 141) resistant to catabolite repression was fully capable of releasing the wild type from catabolite repression while it caused hyperproduction of cellulases in glycerol repressed cultures. The relief of the catabolite repression was also accompanied by a dramatic drop in enhanced protease levels, thereby indicating that the synthesis of proteases (during the catabolite repression) is under the control of cyclic AMP.
Stability of plasmid pBR 322 in escherichia coli nf 161 (rela+) and nf 162 (rel a) grown in a methionine limited chemostat
Authors: Hofmann K. H. , Schweder T. , Reinhardt U. , Hecker M.
Published: December 2004

The stability of the plasmid pBR 322 was measured in E. coli NF 161 (rel A+) and NF 162 (rel A) grown in a methionine limited chemostat. A significant plasmid loss occurred only in E. coli NF 162 at a low dilution rate and if the fermenter had been inoculated with cells from the stationary phase. Obviously, this behaviour resulted from the high expression of β‐lactamase due to amplification of the pBR 322 DNA in the inoculum cells of E. coli NF162.
Studies of the root nodules of leguminous plants IV: Production of indole acetic acid by a bradyrhizobium sp. from the root nodules of a leguminous shrub, crotalaria retusa L
Authors: Bhattacharyya R. N. , Basu P. S.
Published: December 2004

Bradyrhizobium sp. isolated from the root nodules of a leguminous shrub, Crotalaria retusa L., produced a high amount of indole acetic acid (IAA) from tryptophan in the culture. The bacteria preferred D‐isomer to the DL‐ or L‐isomer of tryptophan for the IAA production. The IAA production could be increased up to 153.6% over control by supplementing the medium with arabinose (0.5%), ZnSO4(0.01 μg/ml), KNO3 (0.1%), thiamine‐HCl (0.01 μg/ml) and EDTA (5 μg/ml).

The possible role of the rhizobial production of IAA with the rhizobia‐legume symbiosis is discussed.
An Algorithm for operating a fed‐batch fermentation using quasi‐steady state
Authors: Panov D. P. , Kristapsons M. Z.
Published: December 2004

The determination of an optimum feeding profile of a fed‐batch fermentation requires the solution of a singular optimum control problem, which is often complicated by changes in the process kinetics during the fermentation. The procedure of optimization may be sufficiently simple, if the feeding part of fermentation is carried out in the quasi‐steady state. In this work an algorithm for operating a fed‐batch fermentation using mentioned regime is offered. The algorithm supposes a periodical correction of the feeding strategy. Applying to fed‐batch lysine fermentation demonstrate efficacy of this algorithm over frequently used strategies.
High performance fermentation process using methanol utilizing acidophilic bacteria
Authors: Pöhland H.‐D. , Hühn H.‐J. , Prause M. , Schulze E. , Schurig K.‐H. , Soyez K.
Published: December 2004

Using a methanol utilizing acidophilic MB 58 bacteria strain (IMET 10945T), a stable fermentation process was performed in a pilot plant pressure fermenter of 250 l total volume for more than four months.

Under the fermentation conditions (system pressure and retention time) used, productivities ranged between 2.3 and 9.4 BDM kg−1. h−1 and growth yields between 0.31 and 0.42.

Models describe the correlations between yield and retention time. The mean value of growth yield amounts to 0.41 at a retention time of 6.5 h.
Comparison of various ways of extraction of nucleic acids and of preparation of yeast extract from saccharomyces cerevisiae and candida utilis
Authors: Běhalová B. , Bláhová M. , Šillinger V. , Machek F.
Published: December 2004

Six different variations of the extraction procedure applied to yeast cells of Saccharomyces cerevisiae and Candida utilis to optimize the production of yeast extract and isolation of nucleic acids were compared. The autolysis of C. utilis at 50 to 52°C without adding chemical agents was found to be the best for the production of yeast extract. The most suitable procedures used for the extraction of nucleic acids were those which were carried out from C. utilis at pH 7.5 (92°C) and the other with 0.4 M NH4OH (40°C). Both these modifications yielded the highest amounts of polymer nucleic acids. Applying all procedures compared to S. cerevisiae an increased content of sterols (including Δ5.7‐sterols, predominantly ergosterol) was detected.
Microencapsulation of hybridomas by cellulose sulfate‐polydimethyldiallylammonium chloride procedure
Authors: Groot‐Wassink T. , Dautzenberg H. , Grunow R. , Von Baehr R.
Published: December 2004

Two hybridoma cell lines of human origin and two of murine origin were encapsulated using the cellulose sulfate‐polydimethyldiallylammonium chloride procedure. All lines could be cultivated in capsules, but the time of growth and product synthesis were limited.

The membranes formed were impermeable to albumin and transferrin over a period of 240 minutes. Therefore, the stop of cell proliferation is assumed to be caused by the lack of at least these two proteins. The cell densities inside the capsules reached a maximum of 4.1 × 106/ml (human line) and 3.9 × 107/ml (murine line). The maximum product concentration in the capsules measured by IgG‐ and IgM‐ELISA was 0.17 mg/ml (human line) and 7 mg/ml (murine line). The calculated corresponding retention was 93% (human IgM) and 52% (murine IgG). The characterization of the product showed that the immunoglobulin was not intact and might have been destroyed during harvest. Using the same cell lines the method was compared with the alginate‐PLL procedure originally developed by LIM and SUN [1].
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

High‐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

The 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

It 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

The 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

The 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

The 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

Oats 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

The 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

Several 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

Water 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

The 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

Pretreated 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

The 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

The 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

The 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

The 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

The 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

Fifteen 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

The 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

The 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

Different 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

Sweet 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

Studies 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

The 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

α‐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.
Capacities and limits of three different technologies for the biological treatment of leachate from solid waste landfill sites
Authors: Martienssen M. , Schulze R. , Simon J.
Published: December 2004

Leachate from a municipal waste landfill site was treated using an activated sludge bioreactor, a fluidized bed biofilm reactor and a packed‐bed column reactor (trickling filter).

The leachate contained high organic matter (2.0–2.6 g/l of COD), high ammonium (300–700 mg/l) and sulphide (200–800 mg/l) concentrations, as well as low metal concentrations.

The continuously operating reactors were employed to study the effects of TOC loading on the removal of TOC as well as on the nitrification and denitrification processes.

Among the three biological treatment technologies investigated, the fluidized bed biofilm reactor was best with respect to removing ammonia and TOC. More than 90% of TOC and 99% of ammonia were removed when TOC loading was less than 0.5 kg/m3 × d. At a TOC loading of 4 kg/m3 × d, the removal of TOC and ammonia was 80% and 99%, respectively.

In contrast, the treatment of leachate with the packed‐bed reactor was successful in TOC removing only at TOC loading less than 0.3 kg/m3 × d (TOC elimination decreased from 86% at 0.06 kg/m3 × d to 60% at 0.3 kg/m3 × d). However, the reactor was active in nitrification even at a higher TOC loading (more than a 98% ammonia elimination at a TOC loading of 0.5 kg/m3 × d).

Leachate was processed in the activated sludge reactor when TOC loading was less than 0.5 kg/m3 × d (with a removal of TOC and ammonia up to 83% and 99%, respectively). The activated sludge reactor was also effective in TOC removal at a higher TOC loading (e.g. a 74% TOC removal at a TOC loading of 1 kg/m3 × d), but for ammonia elimination, the activity continuously decreased (less than 60% ammonia removal at a TOC loading of 1 kg/m3 × d).

Overloading in the activated sludge system was indicated by a high concentration of ammonia and nitrite in the effluent. In the packed bed reactor, overloading was characterized by a progressively incomplete TOC removal. No significant overloading was found in the fluidized bed reactor up to a TOC loading of 4 kg/m3 × d.
The molecular cloning and sequencing of the nitrilase gene of Rhodococcus rhodochrous PA‐34
Authors: Bhalla T. C. , Aoshima M. , Misawa S. , Muramatsu R. , Furuhashi K.
Published: December 2004

The nitrilase of Rhodococcus rhodochrous PA‐34 catalyzes the production of optically active amino acids from aminonitriles. The amino acid sequence of the NH2 terminus of the purified nitrilase was determined for the preparation of a synthetic oligonucleotide as a southern hybridization probe. A 9.5‐kbp Pst I‐fragement, which hybridized with the oligonucleotide probe, was isolated from R. rhodochrous PA‐34 genomic libraries constructed in pUC 19. Nucleotide sequence analysis revealed that the nitrilase gene codes for a putative polypeptide of 380 amino acids which correspond to a relative molecular weight of 41, 723.
Studies of the mixing character and flow distribution in mycelial fermentation broths
Authors: Vanags J. J. , Viesturs U. E. , Priede M. A.
Published: December 2004

The influence of two mixing systems on the principal parameters of mycelial fermentations of Aspergillus niger, Fusicoccum amygdali Del. and Fusarium moniliforme Sheld. as well as their metabolite citric acid, fusicoccin and gibberellic acid production was analyzed from the viewpoint of flow energy distribution in a bioreactor.

The growth and metabolite synthesis during fermentation was compared under different mixing conditions in the fermenter FU‐8 with a turbine mixing system (TMS) and a counterflow mixing system (CMS). It was found that the growth, productivity and respiration characteristics as well as the morphology of these cultures varied dependent on the mixing system and agitation regime used. The counterflow mixing system was more favourable for large agglomerates (F. amygdali) or soft pellets (A. niger) forming fungi, while the turbine mixing system was more effective for F. moniliforme growing in the form of small clumps and freely dispersed hyphae. Flow characteristics under different mixing conditions were analyzed in a model fermenter.

The kinetic energy of flow fluctuations was measured in gassed and ungassed water and different fermentation broth systems by using a Stirring Intensity Measuring Device (SIMD‐F1). The difference of the energy values at different points was better expressed in the fermenter with a turbine mixing system in comparison with that having a counterflow mixing system. High viscous F. amygdali and A. niger broth provided higher energy values compared to water and low viscous F. moniliforme broth. It was observed that the intensity of growth and the intensity of the synthesis decreased at very high energy values, which was obviously connected to the influence of the irreversible shear stress on the mycelial morphology.
Kinetic study of the anaerobic degradation of toluene by a mixed culture
Authors: Chaduhri B. K. , Wiesmann U.
Published: December 2004

Toluene was anaerobically degraded by an enriched mixed culture under methanogenic conditions. The mixed culture was originally developed from cow‐dung and sludge from a laboratory reactor, in which benzene was anerobically degraded by sulphate‐reducing bacteria. First the mixed culture was enriched on toluene over a year with and without the use of sulphate in the medium. For the evaluation of growth‐kinetic and maintenance parameters, namely μmax, Ks, kd and Y, the anaerobic degradation of toluene was carried out in batch as well as in continous reactors systems. The gas volume and the methane content in the produced gas was somewhat lover than the theoretical value expected, indicating an incomplete degradation of some of the complex intermediates of the toluene degradation pathway. However, the mixed culture was able to transform 41.3% of the toluene carbon into methane.
Extracellular acid phosphatase as a minor enzyme during the production of proteinases by Humicola lutea 120–5
Authors: Tchorbanov B. , Aleksieva P. , Dambadarja N. , Dyulgerova G.
Published: December 2004

Extracellular acid phosphatase was studied as a minor enzyme of the fungal strain Humicola lutea 120–5 having a clear relation to the secretion of acid proteinases. A medium lacking in mineral orthophosphates ensured a fivefold higher yield of phosphatase while the proteinase production was reduced. An acid phosphatase fraction free of proteinase activity was isolated demonstrating a maximum hydrolysis of 4‐nitrophenyl‐phosphate at a pH of 4.0 and 50°C. The phosphatase catalyzed a partial dephosphorylation of up to 30% of casein at a pH of 3.0 causing a complete substrate precipitation. Both proteinase and phosphatase biosynthesis increased twofold when natural casein was replaced by partially dephosphorylated casein in the cultivation medium.
Studies on polyphosphate and poly‐β‐hydroxyalkanoate accumulation in Acinetobacter johnsonii 120 and some other bacteria from activated sludge in batch and continuous culture
Authors: Weltin D. , Hoffmeister D. , Dott W. , Kämpfer P.
Published: December 2004

Twelve bacterial isolates, four of them assigned to the genus Acinetobacter, were taken from sewage of a treatment plant with Enhanced Biological Phosphorus Removal (EBPR) and screened for phosphorus uptake, polyphosphate (polyP) accumulation and adsorption under limited carbon and nitrogen conditions. In addition, poly‐β‐hydroxyalkanoate (PHA) production was studied under carbon, nitrogen, phosphorus, and oxygen limitation. Under C limitation, the uptake of phosphorus was highest, ranging up to 66 mg P per g dry weight (dw) for the Acinetobacter isolates, whereas the highest amount of polyP was detected under limited N conditions (up to 25 mg PolyP / g dw). Extra‐cellular polyP was detected, however to a minor extent, accounting for a maximum of 10% of the total polyP in one Acinetobacter isolate. The highest PHA concentration (given as 3‐hydroxybutyrate, 3 HB) with 211 mg 3 HB / g dry weight (21% of the dried cell mass) was found for A. johnsonii 120 under nitrogen limitation, but also under P and O2 limitation, PHA, mainly poly‐β‐hydroxybutyrate and poly‐β‐hydroxyvalerate, were produced. Three isolates, assigned to the genus Pseudomonas, showed even higher values (345–427 mg 3 HB / g dw) under N limitation. Studies with Acinetobacter johnsonii 120 in continuous culture, simulating the aerobic/anaerobic periods of a waste‐water treatment plant, resulted in a P elimination of 36% at an anaerobic contact time of 0.6 h. This value increased to 51% at an anaerobic contact time of 3.1 h. No release of phosphate and no uptake of acetate could be detected during the anaerobic period. In addition, Acinetobacter johnsonii 120 was not able to synthesize PHA under anaerobic conditions. By changing the anaerobic conditions to aerobic, a continuous decrease of the polyP content relative to the totalP content from 45% (day 1 of the aerobic process) to 19% (day 17 of the aerobic process) was observed. The amount of PHA increased to 50.4 mg 3 HB/g dw under aerobic conditions. The results indicate again that the EPBR process cannot be defined by simply applying the knowledge of the metabolic processes, observed or assumed in Acinetobacter pure cultures, to the complexity of the process in sewage treatment plants.
Describing microbial degradation processes with the EVOLON model
Authors: Bley Th. , Albrecht K.‐F. , Miethe D. , Riis V. , Babel W.
Published: December 2004

The remediation of polluted soils by microbial communities is a complex process, characterized by many competitive and cooperative mutual relations between the individual organisms. For the overall characteristic of such processes, top‐down systems analyses promise a better description for prognostic aims than bottom‐up approaches.

This is demonstrated using the EVOLON model to fit the cumulative O2 consumption data of a microbial ecosystem metabolizing diesel fuel in polluted soil. The EVOLON is a generic top‐down model providing close approximation to the experimental data.

The advantage of using this model instead of other similar models is demonstrated by a comparison of the deviations between model values and experimental data (residuals).