bluuebunny/crossref_metadata_2025 huggingface dataset:
Reinigung und Charakterisierung von cAMP‐abhängigen Proteinkinasen bei Hefen in einem Saccharomyces cerevisiae Wildstamm und ausgewählten Mutanten des cAMP‐Stoffwechsels
Authors: Sachse O. , Jelen H.
Published: February 2007

Protein kinases represent a diverse family of enzymes that play a critical role in regulation. Among nearly 100 known protein kinases, the cAMP‐dependent enzyme is best understood biochemically. Unlike other protein kinases, cAMP‐dependent protein kinase consists of two different types of subunits that dissociate, a regulatory subunit (R), which is the receptor for cAMP, and a catalytic subunit (C). In the absence of cAMP, the enzyme exists as an inactive tetramer, R2C2. The binding of intracellular cAMP to the R subunit decreases the affinity of the R subunit for the C subunit by approximately four orders of magnitude and, under physiological conditions, leads to dissociation of the holoenzyme into R2(cAMP)4 dimer and two free C subunits that are catalytically active. Mutants of the cAMP metabolism, adenylate cyclase and cell cycle mutants, provided further information about protein synthesis and cellular growth in Saccharomyces cerevisiae. The purified protein kinases were divided into different types according to their elution profiles from the DEAE‐cellulose matrix. Two types of cAMP‐dependent and two types of cAMP‐independent protein kinases were isolated from the wild strain. Differences in the activities of the kinases in the mutants showed a close relationship to the locus of the respective mutations in the cell‐cycle. Some properties of the protein kinases are discussed with respect to individual mutations.
On the role of 26‐deoxylaidlomycin in laidlomycin biosynthesis
Authors: Gräfe U. , Stengel C.
Published: February 2007

3H‐26‐deoxylaidlomycin (I) was fed to growing cultures of Streptoverticillium olivoreticuli IMET 43782 producing both I and laidlomycin (II). The incorporation of labelled I into laidlomycin II was neglible showing a role of I as precursor of II to be at variance. Otherwise, a measurable conversion was achieved by the use of sonicated 48 hrs mycelium suggesting that final oxidation of I to II could be mediated by a compartmentized oxidoreductase.
Production of xylanase by Verticillium albo‐atrum in the presence of polymeric substances
Authors: Bahkali A. H.
Published: February 2007

The production of xylanase in the presence of various polymeric substrates was studied. Among the polymeric substrates, xylan was the best inducer of xylanase by V. albo‐atrum. Other cellulolytic enzymes such as glucanase and β‐glucosidase were synthesized in smaller quantities. The process of degradation indicated that xylanase behaved as typical endo enzyme causing first production of high mol. wt. products. Studies on xylan medium indicated that V. albo‐atrum produced at least three enzymes which degrade xylan.
Reduction of saturated derivatives of testosterone by a strain of Aphanocladium album
Authors: Dmochowska‐Gladysz Jadwiga
Published: February 2007

A strain of Aphanocladium album was found to reduce carbonyl group at C‐3 in 5α‐ and 5β‐dihydroderivatives of testosterone and androstendione. Stereochemistry of this reduction depends on the geometry of ring junction as well as on the presence of substituents (CH3 at C‐4, OAc at C‐17, or OH at C‐19). The simultaneous presence of both CH3 at C‐4 and OAc at C‐17 inhibits the reduction totally in both 5α‐ and 5β‐isomer. The substrates containing a carbonyl group at C‐17 were reduced to 17β‐alcohol.
15α‐Hydroxylation of 13‐ethyl‐gon‐4‐ene‐3,17‐dione using a hyphal fungus immobilized in calcium alginate gel beads
Authors: Schlosser D. , Schmauder H.‐P.
Published: February 2007

Calcium alginate‐entrapped mycelium of Penicillium raistrickii i 477 was used for the 15α‐hydroxylation of 13‐ethyl‐gon‐4‐ene‐3,17‐dione. The system was tested in 10 batches during 40 days of operation, the catalytic activity could be completely regenerated by incubation in a nutrient medium between several batches.
Thermophilic actinomycetes associated with agro‐environment of Punjab State (India)
Authors: Singh S. , Sandhu M. S. , Singh M. , Harchand R. K.
Published: February 2007

Thermophilic actinomycetes (TAs) are unique high temperature aerobic bacteria which belong to the group actinomycetes. While working on hypersensitivity pneumonitis (HP), an immunological disorder, resulting from the inhalation of spores of thermophilic actinomycetes, it was considered worthwhile to record their occurrence in the environment of Punjab. Thermophilic actinomycetes isolated by spread plate method from nine different substrates of the Punjab environment were identified as 8 different species. Atmospheric occurence of TAs was detected by exposing Petri dishes containing soy agar medium which were exposed in six different environments of the state. Seven thermophilic species were recorded. Thermoactinomyces vulgaris was the predominant species with 87.5, 87.1, and 100% prevalence in the soil, natural manure and the wheat field, respectively. The study is the first report of its kind from this region.
Interactions of Mycobacterium fortuitum with solid sterol substrate particles
Authors: Atrat P. , Hösel P. , Richter W. , Meyer H. W. , Hörhold C.
Published: February 2007

Mycobacterium fortuitum NRRL B‐8119 transformes sterols into 9 alpha‐hydroxy‐androsta‐4‐ene‐3,17‐dione (9OH‐AD) at high efficieny. Cells strongly aggregate to the surface of the sterol particles forming stable agglomerates (“substrate immobilized cells”). Substrate uptake and product formation were studied as function of the size of the sterol particles. Using particle sizes comparable with the size of the mycobacterial cells (> 5μm) highest rates were found for both the substrate uptake and the product formation. After mechanical reinforcement of the contact between mycobacterial cells and the sterol substrate by co‐grinding of the components, a significantly increased product formation was observed. Associated cells and cell‐sterol agglomerates were investigated by freeze‐fracture electron microscopy. The micrographs obtained demonstrate that cells of M. fortuitum are growing into the sterol microcrystallite. The uptake of the sterol substrate is assumed to take place via direct contact between cells and the substrate particles. To understand the transport mechanism a model is proposed that includes a flexible multicomponent mesophase (FMCM) which is placed between cells and particles and which mediates the sterol uptake. The putative FMCM is assumed to be composed of mycobacterial glycolipids, extracellular biolipids, synthetical detergents, sterol and water.
Comparative study of external and internal β‐glucosidases and glucoamylase of Arxula adeninivorans
Authors: Büttner Roland , Bode RÜDiger , Birnbaum Dieter
Published: February 2007

Properties of external and internal β‐glucosidases and glucoamylase of Arxula ademinivorans were compared. For the purification of enzymes, the C‐catabolite derepression mutant SBUB 724/41 was used. The following Km‐values for β‐glucosidases with cellobiose as substrate were measured: 14.3 mm (external β‐glucosidase I), 4.1 mm, Ixternal β‐glucosidase I), 5.0 mm (internal β‐glucosidase II), 3.0 mm (external β‐glucosidase II). The Km‐values of the glucoamylase for maltose were 4.6 mm (internal enzyme), 11.1 mm (external enzyme), and for starch 0.32 g/1 and 1.2 g/1, respectively.

Both external β‐glucosidases showed a relatively sharp pH‐optimum in a range from 4.5 to 5.5 while that of internal enzymes was between 5.5 and 6.0. No differences were obtained between pH‐optima (4.5‐5.5) of internal and external glucoamylase. The temperature optimum values of internal β‐glucosidase I (40°C) and of internal β‐glucosidase II (50°C) were remarbably low compared with those of the external β‐glucosidases (60–63°C) and both glucoamylases (60°C).

Molecular mass of 570 kD for the external and of 290 kd for the internal β‐glucosidase I, on the one hand, and of 525 kD and 180 kD for the internal β‐glucosidase II on the other hand were determined. The external gucoamylase consists of two subunits with a molecular mass of 110 kD. After deglycosylation a molecular mass of 76 kD was measured, indicating a carbohydrate content of 30%. whereas for the internal enzyme, a molecular mass of 95 kD was estimated.
Mycoflora associated with five species of freshwater leeches
Authors: Khallil Abdel‐Raouf M. , Bagy M. M. K. , El‐Shimy N. A.
Published: February 2007

Twenty‐two species belonging to 11 genera of zoosporic fungi were collected from 10 freshwater sites and from five species of leeches on sesame and hemp seeds, maize grains and Pinus pollen grains as baits at 22°C. Dictyuchus, Achlya, Pythium, Allomyces and Saprolegnia were the most common genera. The highest population of zoosporic fungi was estimated from Batracobdelloides tricarinata, the lowest from Barbronia assiuti.

In addition fifty‐three species and 1 variety representing 23 terrestrial fungal genera were identified on glucose (17 genera and 41 species) and cellulose (20 genera and 34 species + 1 variety) Czapek's Dox agar at 28°C. The most common species on the two media were Aspergillus niger, A. fumigatus, A. flavus, Trichoderma harzianum, Gibberella fujikuroi and Penicillium chrysogenum. Some fungi were common only on cellulose agar medium such as Botryotrichum atrogriseum, Chaetomium bostrychodes, Dactylella alaskana and Drechslera halodes.

Batracobdelloides tricarinata was the richest with terrestrial fungi whereas Salifa delicata was the poorest.

Five leech species, namely Alboglossiphonia polypompholyx, Batracobdelloides tricarinata, Helobdella conifera, Barbronia assiuti and Salifa delicata were used during this investigation.
Location of branches within the apical hyphal region of Streptomyces granaticolor mycelia
Authors: Kretschmer S.
Published: February 2007

The 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

Using 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

Hydrolysis 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

Azoreductases 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

A 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

Effect 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

The 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

β‐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

Several 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

To 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

Experiments 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

Oxidation 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

A 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

The 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

The 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

The 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

The 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

A 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

Three 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

Legionella 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

The 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

Cell 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.
A genetic study of apramycin‐resistant mutants of Escherichia coli
Authors: Vasiljevic Branka , Fira Djordje , Topisirovic Ljubisa
Published: February 2007

The apramycin‐resistant mutants of E. coli were isolated spontaneously. Mutations, aprA and aprB, conferring resistance to apramycin were located at 72 min on the E. coli genetic map where most of ribosomal genes were mapped. One of the mutants, carrying the aprB mutation, has an altered translational fidelity expressed as severe restriction of amber suppressor activity in vivo. The chromosome location and altered translational fidelity indicate that the apramycin‐resistant phenotype could be a consequence of an alteration of the ribosomal structure.
Physiological and enzymatic characterization of cephalosporin acylases‐producing strain Pseudomonas L24
Authors: Zhang Qui‐Jiu , Xu Wan‐Xue
Published: February 2007

Cephalosporin acylases‐producing strain L24 was isolated from soil sample. The morphological, physiological and enzymatic properties were studied. The results suggest that this strain belongs to the genus Pseudomonas and is designated as Pseudomonas strain L24. The enzymes produced by the cells can convert both cephalosporin C and 7 ‐Gl‐(4‐carboxylbutanamido) into 7‐amino cephalosporanic acid.
Characterization of the Rhodococcus sp. BPG‐8 resorcinol hydroxylase
Authors: Armstrong S. M. , Patel T. R.
Published: February 2007

A thermo‐unstable hydroxylase was isolated from a Rhodococcus sp. BPG‐8. Activity for the partially purified hydroxylase was enhanced and stabilized in the presence of FAD and catalase. The Vmax values for the oxidation of NADH was 0.28 μmoles · min−1 · mg−1 protein and Km value was 8.3 μM in the presence of these compounds, while in their absence the Vmax value was reduced to 0.09 μmoles · min−1 · mg−1 protein while the Km value changed to 16.1 μM. Resorcinol hydroxylase activity was optimal at pH 7.0, and 25° C. The optimal substrate concentrations were 68 μM and 125 μM in the presence and absence of FAD/catalase, respectively. Chloride ion, and metal ions inhibited the resorcinol hydroxylase activity. The resorcinol hydroxylase utilized various other substrates, and did not influence the hydroxylase activity in the presence of resorcinol.
Fungi from water, soil and air polluted by the industrial effluents of Manquabad superphosphate factory (Assiut, Egypt)
Authors: Khallil A. M. , Abdel‐Sater M. A.
Published: February 2007

One hundred and one species in addition to three varieties appertaining to 53 genera of zoosporic (25 species and 15 genera) and terrestrial (76 species + 3 varieties and 38 genera) fungi were isolated during this investigation. The water and submerged mud directly exposed to industrial effluents were the poorest in terrestrial fungi whereas zoosporic fungi were completely missed. These samples were highly acidic, low content of oxygen and relatively high contents of total soluble salts, phosphate, sulphate, calcium and magnesium. Dictyuchus sterilis and Aphanomyces laevis were the most common zoosporic species using baiting technique whereas Aspergillus fumigatus, A. niger, A. flavus, Alternaria alternata, Gibberella fujikuroi and Stachybotrys chartarum were the most prevalent terrestrial fungal species using glucose‐ and cellulose‐CZAPEK's agar media. Tripospermum sp. (aquatic hyphomycetes) was isolated from the phyllosphere of Myriophyllum spicatum and is new record to Egypt. There are some variations concerning the fungal diversity frequencies and populations with regard to the test sources and media used.
Toxigenic fungi and mycotoxin content in poultry feedstuff ingredients
Authors: Mahmoud A.‐L. E.
Published: February 2007

Fifty isolates of Aspergillus flavus as well as 25 isolates of each of A. fumigatus, A. ochraceus, A. terreus and Fusarium spp. isolated from poultry feeds were screened for toxin production. Of these isolates, 20% have been detected to exhibited toxigenic activity.

The mycotoxin content was determined in samples of grind maize, cotton‐seed cake, fish meal, wheat bran and soybean meal. 80% of maize samples were highly contaminated with aflatoxins (480 μ/kg) and zearalenone (40 μ/kg). Aflatoxins B1 and B2 were found in 50 and 30% of cotton‐seed cake and fish meal, respectively. With wheat bran, 40% of the samples contained aflatoxin B1 and zearalenone. Soybean meal appeared to be a poor substrate for mycotoxin formation.
Nutritional factors controlling exocellular proteinase production in a soil‐isolated Xanthomonas maltophilia strain
Authors: Singer Elisabeth , Debette Jaqueline
Published: February 2007

The exoproteinase of Xanthomonas maltophilia C17 is secreted in the absence of any inducer. When a carbohydrate source (glucose, mannose, cellobiose or maltose) is added to casein‐containing cultures, the bacterial growth is increased to the same extent regardless of the nature of the carbohydrate added. Conversely, proteinase production is enhanced in the presence of cellobiose or glucose, but is repressed in the presence of mannose or maltose compared to the control culture grown without sugar. This repression does not result in an accumulation of proteinase within the cell and is not due to the failure of some secretion process since the enzyme is synthesized de novo. Maltose and mannose are known to be easily metabolizable substrates for X. maltophilia. They seem to be involved in a kind of catabolite repression that cannot be relieved by the addition of cyclic AMP or dibutyryl cyclic AMP and to exert their effect at the transcriptional level.
Involvement of two genes of superinfecting phage Kappa in curing and induction of prophage Psi in Serratia marcescens HY
Authors: Steiger H.
Published: February 2007

Prophage Ψ carried along with prophage y by Serratia marcescens HY is subject of moderate curing at heteroimmune superinfection of cells from stationary phase with phage χ. Curing becomes considerably more frequent when the bacteria are non‐iysogenic for y. Both Ψ, y‐double‐lysogenic and Ψ‐single‐lysogenic cells with a mutation in the ink gene are very efficiently cured of Ψ if infected by χtay, although this mutant was characterized as being deficient in transactivation of certain genes in prophage y. On the other hand to get efficiently cured after χ wild‐type infection these cells too must be devoid of a y prophage. Thus a y function turned on by tay+ seems to counteract the elimination of Ψ. However, interestingly enough Ψ curing is boosted by a further y function under special circumstances. Efficient curing depends on an intact χtap gene, a gene reported to cause transactivation of certain Ψ genes. Curing at χtay infection is specifically accompanied by induction of the Ψ prophage in a part of the infected cells. However, there is no such induction at χ wild‐type infection, either in the absence or presence of a y prophage. An explanation of these findings is suggested which includes an antirepressive effect exerted on Ψ and a hypothetical interaction between the products of genes tap and tay.
Microbial transformation of isoprenoid systems by means of Zoophthora (Erynia) ovispora (NOWAKOWSKI) BATKO
Authors: Urbańczyk Jerzy M. , Sołoducho Jadwiga , Zabźa Andrzej , Sodano Guido , Grassi Alfonso
Published: February 2007

Epoxidation of double bond was the main reaction performed by Zoophthora (Erynia) ovispora on methyl and ethyl α‐campholenyl ketones 1 and 6. Apart from epoxides 2, 3, 7, and 8, some other products were isolated, with additional oxygen function in α‐position to the double bond (9 and 10). The presence of the BAEYER‐VILLIGER reaction product (4) and diketone 11 is also postulated.
Fermenter cultivation of intestinal spirochaetes
Authors: Borrmann Erika , Blaha Thomas , Günther Horst
Published: February 2007

We cultivated 6 strains of intestinal spirochaetes in a laboratory fermenter under constant conditions (medium, physical‐chemical parameters) in a permanent gas flow. It has been possible to demonstrate that the application of the fermenter technique for the cultivation of spirochaetes is a suitable method which can be easily standardized.
Taxonomy of lactic acid bacteria from spoiled, vacuum packaged vienna sausages by total soluble protein profiles
Authors: Dykes Gary , Holy Alexander Von
Published: February 2007

To resolve the taxonomic status of sixty‐one lactic acid bacteria isolated from spoiled, vacuum packaged vienna sausages, a computer assisted analysis of total soluble protein profiles was undertaken. Sixty‐two % of the strains in the study were recovered in fourteen clusters at the 72% similarity level, indicating high degree of heterogeneity among the strains examined. Two clusters representing Leuconostoc species were the largest and most homogeneous, containing twenty strains between them. One cluster contained both typical Lactobacillus saké and Lactobacillius curvatus strains, indicating the inability of protein profiles to consistently differentiate between all strains of these two species. The presence of an independent Lactobacillus curvatus grouping and the clustering of some atypical strains with Lactobacillus saké isolates, however, indicated that the atypical strains may be closely related to Lactobacillus saké.
Occurrence and characterization of lectins in actinomycetes
Authors: Singh Jatinder , Ahluwalia Jasleena , Kamboj Sukhdev Singh , Singh Surinder
Published: February 2007

25 species of actinomycetes were tested for the occurrence of lectins. Using a battery of normal and desialized erythrocytes, each species was screened for 3 types of lectin activity i.e. surface bound, extracellular and intracellular. As many as 13 species showed one or more types of activity; some of them were characterized with regard to their biological action spectrum and sugar specificity.
Utilization of aromatic compounds by the Penicillium strain Bi 7/2
Authors: Hofrichter Martin , Scheibner Katrin
Published: February 2007

The Penicillium strain Bi 7/2 utilized phenol, catechol, resorcinol, hydroquinone, pyrogallol, hydroxyhydroquinone, phloroglucinol, m‐ and p‐cresol, orcinol, 4‐methylcatechol. 4‐methoxy‐phenol, 4‐aminophenol, benzyl alcohol, benzoic acid, 2‐, 3‐ and 4‐hydroxybenzoic acid, anthranilic acid, protocatechuic acid and gallic acid as sole sources of carbon and energy. The central metabolites catechol, protocatechuic acid and hydroxyquinone could be determined by HPLC with diode‐array detection. Pathways for the degradation of aromatic substances were proposed.
Purification and properties of NAD+‐dependent formate dehydrogenase produced by Agrobacterium sp.
Authors: Iida Mitsugi , Ohtsuki Shin'Ichi , Mineki Shigeru
Published: February 2007

Formate: NAD+ oxidoreductase (EC 1.2.1.2) with high affinity to formate was purified from a facultative formate‐utilizing Agrobacterium sp. MIL 1052. From a cell extract, the enzyme was purified to homogeneity by ammonium sulfate fractionation, DEAE‐Sephadex A‐50 column chromatography, Sephadex G‐200 column chromatography, and hydroxyapatite column chromatography. The enzyme amounted to 9.1% of intracellular soluble proteins in strain MIL 1052. The subunit Mr, estimated by sodium dodecyl sulfate polyacrylamide gel electrophoresis, was 50 kDa. The Mr of the native enzyme was estimated to be 112 kDa by gel filtration, suggesting a dimeric structure. The enzyme had an isoelectric point of 7.0. The pH and temperature optima were 5.5–7.0 and 30–45 °C, respectively. The enzyme was stable at pH 6.0–7.5 and at up to 35 C. The apparent Km values for formate and NAD+ were calculated to be 0.13 mM and 0.17 mM, respectively.
In vitro coronatine production by several Pseudomonas syringae pv. glycinea isolates
Authors: Nüske Jörg , Bublitz Friedemann
Published: February 2007

Coronatine production by several Pseudomonas syringae pv. glycinea strains has been studied in batch culture. A reversed‐phase high‐performance liquid chromatographic procedure was developed for rapid quantitation of coronatine in culture fluids. Coronatine and coronafacic acid have been recognized from their mass spectra. Three of the strains investigated showed no detectable amounts of coronatine. Four of the examined high producing wild type strains produced much more coronatine as have been already reported for P. syringae pv. glycinea strains, none of them showed detectable coronafacic acid production. Coronatine production is strictly growth associated. Two strains showed a break down of coronatine already at the beginning of the stationary growth phase.
Metabolism of aniline and 3‐chloroaniline in Pseudomonas acidovorans CA28: Evidence of isofunctional muconate cycloisomerases
Authors: Hinteregger Christel , Ferschl Andreas , Loidl Michael , Streichsbier Franz
Published: February 2007

Two distinct muconate cycloisomerases are involved in the degradation of aniline and 3‐chloroaniline (3‐CA) proceeding via the ortho‐cleavage pathways in Pseudomonas acidovorans CA28. After partial purification of these two enzymes kinetic investigations resulted in a clear differentiation of aniline‐derived muconate cycloisomerase (MC) and 3‐CA‐derived chloromuconate cycloisomerase (CMC). A further result of this study revealed the simultaneous coexistence of MC and CMC in strain CA28 when grown on a mixture of aniline and 3‐CA.
Investigations of the oxygen supply in Ca‐alginate beads and microcapsules loaded with Penicillium raistrickii using a microelectrode
Authors: Irrgang S. , Baumgärtl H. , Schlosser D. , Zimelka W. , Schmauder H.‐P.
Published: February 2007

The oxygen supply of free, Ca‐alginate entrapped and microencapsulated mycelia of Penicillium raistrickii i 477 capable of 15α‐hydroxylation of 13‐ethyl‐gon‐4‐en‐3,17‐dione was investigated. Using an oxygen microelectrode distinct gradients of oxygen within the Ca‐alginate beads as well as the microcapsules were detected. Slope and width of the gradients were investigated in dependence on the kind of immobilization, the culture age and the cell density on or in the carrier as well as the different forms of the oxygen supply in the medium. So it could be shown that large parts of immobilizates, approximately 96% of the diameter of both types, were oxygen‐free. In comparison with free mycelia, the lower oxygen supply of the immobilized mycelia led to a metabolic shift to fermentative catabolism.
Growth kinetics of Rhodotorula rubra on different substrates
Authors: Hari Ravinder P. K. , Patel Thakor , Martin Antonio M.
Published: February 2007

The growth of a red‐pigmented yeast, isolated from yogurt and identified as Rhodotorula rubra, was studied on various industrial and agricultural by‐products. Peat hydrolysate when supplemented with peptone and yeast extract supported a satisfactory growth of the yeast. Ammonium hydroxide and ammonium sulfate were the best inorganic nitrogen sources. A yield of 11.8 g/1 was obtained on molasses and wort used in a concentration of 10 and 40% (v/v), respectively. Molasses were pre‐treated to be effective. The best yield of 14 g/1, however, was obtained on a richer medium composed of molasses, peptone and yeast extract. The pH profiles were also studied and growth was found within a broad pH zone of 3–10.