bluuebunny/crossref_metadata_2025_split huggingface dataset:
Location of branches within the apical hyphal region of Streptomyces granaticolor mycelia
Authors: Kretschmer S. 
Published: February 2007

AbstractThe location of branches (ramifications) within the apical hyphal region of Streptomyces granaticolor mycelia was studied in dependence on the specific growth rate by using batch and chemostat cultures. The site where a new branch emerged was correlated to the neighboured elongation sites (e‐sites) as well as to the septae.In dependence on the growth rate the distance from a newly formed branch (i. e. e‐site) to the apical e‐site (tip of the main hypha) changed from 12 to 44 μm and to the e‐site on the tip of the preceding neighboured branch from 12 to 27 μm. Thus, except for the slowest grown culture, the new branching site in the apical hyphal region did not represent the midst between the two preexisting e‐sites.Comparing branching and septation sites, the data indicated a close correlation between them, if the respective mean values of whole populations were determined. But regarding individual hyphae, only 4–39% – depending on the growth rate – of the apical branches were directly neighboured to a septum. The remaining percentage was situated at one of several potential branching sites, the number of which per subapical cell corresponded to the number of nucleoids.
Selection and characterization of new microorganisms for the manufacture of 9‐OH‐AD from sterols
Authors: Seidel L. , Hörhold C. 
Published: February 2007

AbstractUsing a special selection procedure, several mutants of Mycobacterium vaccae were isolated which were capable of converting sterols to 9α‐hydroxyandrost‐4‐ene‐3,17‐dion (9‐OH‐AD). Two mutants, Mycobacterium vaccae ZIMET 11052 and 11053, respectively, were further investigated. Strains of the species Mycobacterium fortuitum are mainly used for commercially obtaining 9‐OH‐AD from sterols. In contrast to the species Mycobacterium fortuitum the species Mycobacterium vaccae has not been reported to contain pathogenic strains. This seems an advantage for industrial application. Mutants with the ability of converting sterols to 9α‐hydroxysteroids have a defect in the steroid‐1‐dehydrogenase activity which is, however, only a partial one. The remaining activity may cause an undesirable degradation of the steroid nucleus. The steroid‐1‐dehydrogenase activity was tested using an assay developed by ATRAT (1986). We confirmed two apparently distinct steroid‐1‐dehydrogenases in Mycobacterium fortuitum NRRL B‐8119 as reported by WOVCHA et al. (1979). One of them has an activity on androst‐4‐ene‐3,17‐dion (AD). The activity is increased by induction with sitosterol. The other one is active on 9‐OH‐AD. But Mycobacterium vaccae does not possess steroid‐1‐dehydrogenase activity on 9‐OH‐AD, and the AD specific steroid‐1‐dehydrogenase is not effected by sitosterol. The consequence is a high level of protection against steroid nucleus degradation yielding an effective accumulation of 9‐OH‐AD in fermentations with Mycobacterium vaccae mutants.
Transport and hydrolysis of maltose by Schwanniomyces castellii
Authors: Violle P. , Boze Hélène , Moulin G. , Galzy P. 
Published: February 2007

AbstractHydrolysis and transport of maltose into Schwanniomyces castellii was studied under aerobic and anaerobic conditions. Amylase and glucosidase were not synthetized in presence of maltose in anaerobic conditions. Maltose permease was synthetized in anaerobiosis and its functioning is not inhibited. Glucose strongly repressed induction. The half‐saturation constant for uptake of maltose was 0.06 mM. The rate of uptake of maltose was decreased by 2,4‐dinitrophenol, antimycin or sodium azide. The significance of these results in relation to the KLUYVER effect is discussed.
Immunological homology among azoreductases from Clostridium and Eubacterium strains isolated from human intestinal microflora
Authors: Rafii Fatemeh , Smith Don B. , Benson R. Wayne , Cerniglia Carl E. 
Published: February 2007

AbstractAzoreductases from several anaerobic intestinal bacteria have been shown to reduce azo dyes to carcinogenic aromatic amines. To evaluate the structural similarities of azoreductases from four species of Clostridium and one species of Eubacterium, a polyclonal antibody against purified Clostridium perfringens azoreductase was generated in rabbits. This antibody inhibited the azoreductase activity of all five bacteria tested. ELISA showed different degrees of binding of the antibody to various species of bacteria. In a Western blot, the antibody reacted with the purified azoreductases from all four Clostridium species and the Eubacterium species. These results demonstrate that the azoreductases from the bacteria tested share similar antigenic domains, which are probably located in the active site of the enzyme. Azoreductases from these intestinal bacteria are similar enough to be considered as a single group of enzymes with respect to their functions and antigenicity.
Microbial degradation of shrimp‐shell waste
Authors: Sabry S. A. 
Published: February 2007

AbstractA total of 40 strains of bacteria were isolated and tested for their potentiality to degrade chitin and utilize shrimp‐shell waste for the production of chitinase. The activity ratio, percentage of weight loss and enzyme activity were determined for cultures exhibiting highest chitinolytic activities. The most active organisms were identified as Alcaligenes denitrificans, Bacillus amyloliquefaciens, B. megaterium and B. subtilis. The potentiality of the first two organisms to degrade chitin was reported for the first time.
Action of sodium diethyldithiocarbamate (NaDDC) on the HILL activity and chlorophyll fluorescence in Anacystis nidulans IU 625
Authors: Singh D. P. , Gothalwa R. , Bisen P. S. 
Published: February 2007

AbstractEffect of sodium diethyldithiocarbamate (NaDDC) on chlorophyll fluorescence and HILL activity in Anacystis cells exhibited stimulation of both the processes in a concentration‐dependent manner (SINGH et al. 1989). Treatment of cells with sodium dodecyl sulphate (1% w/v) and tris (0.5 M) resulted into further stimulation of NaDDC supported both fluorescence emission and HILL activity. Addition of energy consuming substrates like NaHCO3 (3 mM) and 3‐phosphoglyceric acid (PGA 1 mM) could bring about quenching of NaDDC stimulated fluorescence. However, fluorescence quenching of carbon substrates could be reversed in presence of DCMU (10 mM). Further, the results on cytochrome‐c reduction, fluorescence emission and pigment absorption in the presence of NaDDC exhibited a pH dependence (6–8) of NaDDC on these processes with maximum effect at pH 6. NaDDC‐induced general increase in the absorbance of pigments accompanied by hypsochromic shifts at 680 and 625 nm were indicative of conformational changes in the pigment protein complexes. The results with energy transfer inhibitors showed that uncouplers like FCCP (10 μM), Nigericin (10 μM) and NH4Cl (1 mM) could significantly alter the effect of NaDDC on fluorescence emission and HILL activity, while antimycin (5 μg/ml) and N‐ethylamaleimide (100 mM) had little effect. These results, taken together, suggested that NaDDC‐induced build up of proton gradient might be resulting into cessation of electron transport and stimulation of fluorescence by exerting a back pressure on the charge separation property of membrane.
Technical bioenergetics and ecosystem biotechnology
Authors: Oleskin Alexander , Samuilov V. D. 
Published: February 2007

AbstractThe present work explores some possible practical uses of bioenergetic processes (fermentation, respiration and photosynthesis) in the microbial cell for the purpose of renewable fuel production. These considerations are based on ecosystem biotechnology which include the following main points:
Creation of closed energy‐transducing ecosystems under laboratory conditions.
Production of renewable energy carriers with the help of microbial communities (e.g., mixed cultures of microorganism).
Investigation of the role of the individual microoganism in the population or community.
Purification and characterization of ß‐xylosidase activities from the yeast Arxula adeninivorans
Authors: Büttner Roland , Bode Rüdiger 
Published: February 2007

Abstractβ‐Xylosidase activity has been detected in cell‐free extracts, in culture fluids and as cell wall‐bound enzyme of Arxula adeninivorans. With chromatographic procedures used to purify the activity two different forms of β‐xylosidase (denoted βX‐1 and βX‐2) from the cell‐free extract and from the culture medium could be separated, but only one form (βX‐2) was present in the cell wall. Both forms are glycoproteins and were deglycosylated by endoglycosidase H treatment. The molecular masses of the enzymes under native and denaturing conditions suggest that βX‐2 is the dimer of βX‐1. Mr of the native βX‐1 was 60 kDa and after deglycosylation 39 kDa determined by sodium dodecyl sulphate polyacrylamide gel electrophoresis. Some enzymatic properties of βX‐1 and βX‐2 and of their deglycosylated products were studied and showed, with one exception, wide similarities. The maximum activity was reached at pH 5.0 and 60 °C. The enzymes hydrolyze only β‐glycosidic bound β‐xylopyranosides and the Km values for p‐nitrophenyl‐β‐xylopyranoside were determined to be 0.23–0.33 mM. The β‐xylosidase acitivity was inhibited competitively by xylose. The deglycosylated enzymes were, however, stronger inhibited (Ki = 2.1 mM) as their glycosylated ones (Ki = 5.8 mM).
Magnetotactic bacteria from freshwater lakes in Georgia
Authors: Matitashvili Elwina A. , Matojan Diana A. , Gendler Tatjana S. , Kurzchalia Teymuras V. , Adamia Revaz S. 
Published: February 2007

AbstractSeveral species of magnetotactic bacteria were discovered in the lakes and ponds of Georgia. Electron microscopic analysis of the bacteria showed a great variety of microbial forms as well as magnetosome arrangements. Pyramidal, cubical or hexagonal magnetic grains could be seen in different species of bacteria. The linear organization of magnetic particles was prevailing, although gathered magnetosomes were also seen. Magnetometric measurement of magnetic particles obtained from coccoid bacteria was performed. Remnent acquisition curves, as well as thermomagnetic curves of investigated material showed that the magnetosomes under study contained pure single‐domain magnetite.
Effect of temperature and medium composition on mycelial growth of Streptomyces tendae in submerged culture
Authors: Reichl U. , King R. , Gilles E. D. 
Published: February 2007

AbstractTo investigate the influence of culture conditions on growth of filamentous bacteria in submerged culture, S. tendae was cultivated at various temperatures and in various media. For this purpose, a temperature‐controlled growth chamber was constructed, which allows the cultivation of filamentous bacteria and fungi in oxygen saturated medium. To observe the development of mycelia emerging from spores, this growth chamber was mounted on a microscope stage and series of images were analyzed by an image processing system. Growth kinetics obtained in liquid culture were identical to those determined on solid media. Specific growth rate and apical extension rates of individual hyphae seemed to be higher than those observed on solid media, due to a better supply of medium in submerged culture. A two‐fold increase in specific growth rate, mean apical extension rate and branching rate was observed when the temperature was increased from 27 °C to 37 °C, therefore, the length of the hyphal growth unit was not changed. Growth in synthetic media used here was considerably slower compared with complex medium. A decrease in glucose concentration from 40.0 gl−1 to 1.0 gl−1 resulted in an increase in branching rate and specific growth rate, while apical extension rate of individual hyphae was unchanged.
Biosynthesis of pyrrolnitrin. Incorporation of 13C, 15N double‐labelled D‐ and L‐tryptophan
Authors: Zhou Pei , Mocek Ursula , Siesel Brian , Floss Heinz G. 
Published: February 2007

AbstractExperiments on the incorporation of D‐ and L‐[alanine‐3‐13C,2‐15N]tryptophan into the antibiotic pyrrolnitrin in Pseudomonas aureofaciens confirmed earlier conclusions about the conversion of L‐tryptophan into pyrrolnitrin. They also demonstrated that a fraction of the D isomer is incorporated without breakage of the 15N‐carbon bond, consistent with the operation of a second pathway from D‐tryptophan to pyrrolnitrin. Cell‐free experiments confirmed the conversion of 3‐(o‐aminophenyl)pyrrole into aminopyrrolnitrin but failed to detect enzymatic oxidation of the latter to pyrrolnitrin.
Oxidation of 3β‐ and 17β‐hydroxysteroids by Nocardia rubra cells in heptane‐water system
Authors: Osipowicz B. , Krȩżel Z. , Siewiński A. 
Published: February 2007

AbstractOxidation of cholesterol, β‐sitosterol, pregnenolone, androstenolone and 5‐androsten‐3β,17β‐diol carried out by Nocardia rubra cells in a mixture of heptane‐water (25:1 vol.) gave 4‐en‐3‐oxo‐steroids with the yield to 100% (holesterol). Simultaneously oxidation of 17β‐hydroxy group in androstendiol and in testosterone was observed as well.
Susceptibility of a line of dolphin kidney cell culture to several herpesviruses
Authors: Kadoi K. , Mochizuki A. , Ikeda T. , Kamata H. , Yukawa M. , Inoue Y. 
Published: February 2007

AbstractA cell line was established from cell cultures of kidney cortex of a pantropical spotted dolphin, Stenella attenuate. The replication of 6 strains of herpesviruses was studied in the cells. Five strains of them, herpes simplex virus type I and type II, equine rhinopneumonitis virus, infectious bovine rhinotracheitis virus and Aujeszky's disease virus, were grown fairly well in showing clear cytopathic effects and plaques under agar overlay medium.
Overexpression of a Rhodococcus erythropolis protein in Escherichia coli with immunological identity to the Rhodococcus steroid 1‐dehydrogenase. Immunoelectron microscopic localization and electrophoretic studies
Authors: Wagner Manfred , Atrat Peter G. , Wagner Barbara , Hanemann Vera , Clark‐Curtiss Josephine E. 
Published: February 2007

AbstractThe recombinant Escherichia coli K‐12 strain x 6060 harbouring the plasmid pYA 1201 with a gene from Rhodococcus erythropolis IMET 7030 overexpressed a protein which reacts with a monospecific antiserum against the steroid 1‐dehydrogenase (Sdh) from the same Rhodococcus strain. It was shown previously that this recombinant protein exhibits no enzymatic activity.By immunogold labelling the protein was localized on ultrathin sections of the recombinant E. coli strain. After cultivation at 37 °C it was found within large cytoplasmic compartments (inclusion bodies). The inclusion bodies occupied 40% to 75% of the sectioned cell area. The highest amount of protein was observed after induction of the culture with isopropyl‐β‐D‐thiogalactopyranoside. Approximately 20% of the induced cells became enlarged (up to 5‐fold of the normal size) and deformed; multiplication of the Rhodococcus protein producing cells was inhibited. After ultrasonic cell disintegration the inclusion bodies were found only in the fraction of the sedimented cell debries and did still react with anti‐Sdh.When recombinant E. coli cells were cultivated at 28 °C, inclusion bodies appeared very seldom and the immunoreactive protein was distributed throughout the whole cytoplasm.
A method based on plate count for enumerating N2O/N2‐producing bacteria from nitrate in the soil
Authors: Allievi Luigi , Möller Frank 
Published: February 2007

AbstractThe production of N2and N2O from NO3‐N can provoke a loss of nitrogen from agricultural land. However, in the case of excessive nitrate it can avoid water pollution. A method for counting the producers of N2and N2O from nitrate in soil, based on the isolation of colonies grown on plates prepared for the total aerobe count, was developed and tested. The method can be used to evaluate a soil bacterial group that includes not only denitrifiers but all N2O producers from nitrate. Randomly selected colonies are transferred into liquid medium and incubated in the presence of 10% acetylene, and N2O production is then determined. Multiplying the fraction of colonies thus detected as N2O‐producing by the total aerobe number yields the N2O/N2producer number. We considered it advisable to consider total aerobe instead of total anaerobe count because the obligate aerobes are prevalent in the soil, and various aerobes, as well as denitrifiers, are N2O producers. The new method was compared with a previously developed method based on the most‐probable‐number procedure using three soils, and the former method had the greater precision. The new method was also applied to two other soils. The percentages of N2O/N2producers ranged in the five soils from 37% to 84% and numbers from 5 to 65 million · g−1.
The metabolism of gluconate in Escherichia coli: A study in continuous culture
Authors: Coello Nereida B. , Istúriz Tomás 
Published: February 2007

AbstractThe gluconate metabolism in Escherichia coli involves duplicate activities of transport and phosphorylation for gluconate. In both cases, these activities can be differentiated in vitro by their different affinities for the substrate. In addition, the two gluconokinases can be differentiated by their heat sensitivities. The technique of continuous culture was used to investigate the influence of the growth rate on this metabolism in an E. coli HfrG6 strain during gluconate‐limited growth under conditions of high and low oxygen concentrations. The transport and phosphorylation for gluconate, induced when the cells are cultivated in media with gluconate were differently influenced by the culture dilution rate. These activities were induced under the two conditions investigated; however, the low affinity transport system for gluconate and the thermosensitive gluconokinase were not detected under conditions of high and low oxygen concentrations, respectively. The induction of the dehydratase was favoured under conditions of low oxygen concentration. The experimental data suggest that induction and repression work together to regulate the levels of these activities during gluconate‐limited growth conditions. Furthermore, that an effector molecule distinct from gluconate might be involved in the induction of the dehydratase.
Neutral lipids of the fungus Zoophthora (Erynia) ovispora (NOWAKOWSKI) BATKO
Authors: Urbańczyk M. J. , Zabźza A. , Cichacz Z. , Cimino G. , Szafranek J. 
Published: February 2007

AbstractThe main components of the neutral lipid fractions, isolated from Zoophthora (Erynia) ovispora, were determined. Triglycerides constitute 56% of total lipids, among them dilaurinostearate glyceride constitutes 43.3%. The major fatty acid – lauric acid (32.3%) is related mainly to tri‐ and diglycerides. The level of stearic acid is slightly lower (29.8%) but distinctly predominates in free acid fraction. Diglycerides and steroids were present in smaller amounts – 1.2% and 4.8%, respectively. Cholesterol exceeds considerably ergosterol.
Fortuitous resorcinol metabolism by a phloroglucinol‐induced Rhodococcus sp. BPG‐8
Authors: Armstrong S. , Patel T. R. 
Published: February 2007

AbstractA Rhodococcus sp. BPG‐8 isolated from oil‐rich soil in Newfoundland was capable of using phloroglucinol as a sole source of carbon and energy. Culture filtrates of cells grown on resorcinol were extracted and analyzed using gas chromatography‐mass spectra (GC‐MS), thin layer chromatography (TLC), and ultraviolet spectrophotometry. Phloroglucinol induced cell‐free extracts revealed the presence of phloroglucinol hydroxylase that hydroxylated resorcinol. Meta‐cleavage of 1,2,4‐benzenentriol occurs at a slow rate. A tentative biotransformation pathway for resorcinol by Rhodococcus sp. BPG‐8 is discussed.
Selective isolation of fluorescent and nonfluorescent Pseudomonas species from Sohag Governorate (Upper Egypt)
Authors: Shoreit Ahmed A. M. , Soltan El‐Sayed 
Published: February 2007

AbstractThree hundred and fourty nine isolates belonging to ten different species of Pseudomonas were isolated and identified from soil and water samples on four selective isolation media: Modified Trypticase soy agar (TSA), ACC‐agar containing ampicillin‐chloramphenicol‐cycloheximide, Nitrate plus organic acid agar and Tryptophan substrate agar. The fluorescent species were P. putida (21.2% of the total Pseudomonas species), P. fluorescens (15.8%), P. aeruginosa (9.7%) and P. aureobaciens (2.6%), while the nonfluorescent species were P. stutzeri (12.4%), P. alcaligenes (11.2%), P. pseudoalcaligenes (9.5%). P. mendocina (8.3%), P. lemoignei (5.7%) and P. ruhlandii (3.4%).Modified TSA and ACC media were efficient for the isolation of both fluorescent and nonfluorescent species, whereas Nitrate and Tryptophan media were more selective for the isolation of nonfluorescent species. The optimum temperature for the isolation of different species ranged between 20 ° and 37 °C.
Ampicillin tolerance of Legionella pneumophila for counter‐selection of transconjugants in heterospecific matings with Escherichia coli donors
Authors: Jain Bunty , Bender Larisa , Lück P. Christian , Ott Manfred 
Published: February 2007

AbstractLegionella pneumophila, the causative agent of Legionaires' disease is sensitive to ampicillin. However, the slowly growing bacteria are not killed even by high doses of this antibiotic. This natural tolerance was used for counter‐selection of trans‐conjugants in heterospecific matings with Escherichia coli as donor. This approach is useful for gentic manipulations in Legionella, as it avoids the use of antibiotic‐resistant variants, which have to be tested for full virulence before use.
The effect of light and glucose concentration on the content of S‐ and R‐glucans in the mycelium of Aspergillus giganteus mut. alba
Authors: Fiema Janina 
Published: February 2007

AbstractThe amounts of S‐ and R‐glucans in the mycelium of Aspergillus giganteus mut. alba depend on light within the range of selected light intensities: 0 W · m−2; 3 W · m−2; 10.6 W · m−2 at 20% glucose concentration in the nutrient medium. This species synthetises the highest amount of S‐glucans at the light intensity 10.6 W · m−2, and that of R‐glucans – at the intensity 3 W · m−2.
Membrane‐bound proteinases of Halobacterium halobium
Authors: Fricke Beate , Parchmann Olaf , Aurich Harald 
Published: February 2007

AbstractCell envelopes of Halobacterium halobium contain proteolytic activities, which cleave 125I‐insulin and 14C‐casein with pH‐optima in the alkaline range. About 50% of the intracellular proteases are strongly attached to the cell envelopes and cannot be removed by washing with 25% sodium chloride solution. This high amount of membrane‐bound proteases is independent of the kind of cultivation. The main part of the envelope‐bound proteolytic activity is attributed to metalloproteases, with EDTA and o‐phenanthroline causing inhibition. Serine and cysteine protease inhibitors had no influence.In density gradients (consisting of Ficoll and 20% sodium chloride) proteolytic activities could be detected in two distinct bands, a minor band at a density of 1.165 and the main proteolytic activity at 1.145 g/cm3. When the cell wall was removed from the other cell envelope constituents by EDTA treatment, a single band with proteolytic activity in the density gradient at 1.145 g/cm3 was detectable.Lubrol, Brij 35, and octyl glucoside were used for the solubilization of the membrane‐bound proteases. The greatest part of them could be solubilized using 0.2% octyl glucoside.14C‐labelled bacteriorhodopsin was not cleaved by any of the intracellular or extracellular proteinases.