bluuebunny/crossref_metadata_2025 huggingface dataset:
Hemagglutinating activity in phytopathogenic bacteria surface compounds
Authors: Serra M. Teresa , Castresana M. Carmen , Tejerina Genoveva
Published: February 2007

Extracellular components of plant pathogenic bacteria were obtained from their culture medium as well as from the whole cells by using NaCl 1 M, pH 6.0; 20% sucrose dissolved in 0.03 M Tris buffer, pH 8.0; or 0.05 M Na2EDTA.

All the extracts from Erwinia carotovora subsp. carotovora, Xanthomonas campestris pv. campestris, Pseudomonas syrinagae pv. phaseolicola, Xanthomonas campestris pv. phaseoli, Pseudomonas solanacearum, and Erwinia carotovora subsp. atroseptica, were assayed for hemagglutinating activity on sheep, rabbit and chicken red blood cells (RBCs).

The only active extracts were those obtained by NaCl treatment. They agglutinated sheep and rabbit erythrocytes. Extracts from E. carotovora subsp. atrose ptica gave rise to the high agglutination titer on rabbit RBCs. These extracts had the lowest polysaccharide/protein ratio. E. carotovora subsp. carotovora extracts showed only a low titer (18.5 units).

The agglutinating activity present in NaCl extracts of the bacteria tested was inhibited by different carbohydrates to various extent. Extracts from E. carotovora subsp. atroseptica appeared to be the most sensitive ones while those of E. carotovora subsp. carotovora least sensitive to the presence of sugar.

It is suggested that hemagglutinins observed in plant pathogenic bacteria and those in plant host are similar and that both may, in some way, be involved in the plant‐parasite relationship.
Decomposition of angiospermic wood sawdust and laccase production by two Pleurotus species
Authors: Arora D. S. , Sandhu D. K.
Published: February 2007

Out of different lignin preparations, phenolic compounds and sugars tested, indulin AT proved to be the best substrate for laccase production in both Pleurotus ostreatus and P. sajor‐caju. Sugars supported good growth but repressed enzyme production. In P. ostreatus the enzyme production was maximum at 25 °C, pH 5 and 0.1% indulin AT. Angiospermic wood saw dust suffered a total weight loss of 6% accompanied by 14% lignin loss during 60 days incubation with P. ostreatus.
Temperature dependence of M pilus formation as demonstrated by electron microscopy
Authors: Karste Gunter , Adler Klaus , Tschäpe Helmut
Published: February 2007

The formation of IncM plasmid encoded pili is dependent on the incubation temperature of the corresponding host strains.

By labelling the short, rigid M pili with the donor specific bacteriophage ØM, the presence of pili at 30 °C but not at 37 °C incubation temperature colud be demonstrated for E. coli K 12 substrains carrying different IncM group plasmids. In contrast, such a temperature dependence of M pilus formation is not observed in S. typhimurium substrains.
Natural mediators of physiological interferon synthesis
Authors: Błh‐Olszewska Zofia
Published: February 2007

Resident peritoneal cells of BALB/c mice were found to release two types of mediatros influencing physiological interferon synthesis, a nondialysable stimulator and a dialysable low molecular inhibitor.

The influence of macrophage secreted, biologically active substances on interferon production is discussed. Their participation in the induction of physiological interferons is considered.
Differential suppressor effects of the ssb‐1 and ssb‐113 alleles on uvrD mutator of Escherichia coli in DNA repair and mutagenesis
Authors: Quiñones Ariel , Piechocki Reinhard
Published: February 2007

We have constructed double mutants carrying eithre ssb‐1 or ssb‐113 alleles, which encode emperature‐sensitive single strand DNA binding proteins (SSB), and the uvrD::Tn5 allele causing deficiency in DNA helicase II, and have examined sensitivity to ultraviolet light (UV), recombination and spontaneous as well as UV‐induced mutagenesis.

We have found in a recA+ background that (i) none of the ssb uvrD double mutants was more sensitive to UV than either single mutant; (ii) the ssb‐1 allel partially suppressed the strong UV sensitivity of uvrD::Tn5 mutants; (iii) in the recA730 background with constitutive SOS expression, the ssb‐1 and ssb‐113 alleles suprpessed the strong UV‐sensitivity caused by the uvrD::Tn5 mutantion; (iv) in ssb‐113 mutants, the level of recombination was reduced only 10‐fold but 100‐fold in ssb‐1 mutants, showing the there was no correlation ebtween the DNA repair deficiency and the recombination deficiency; (v) the hyper‐recombination phenotype of the uvrD::Tn5 mutant was suppressed by the addition of either the ssb‐1 or the ssb‐113 allel: (vi) no addition of the spontaneous mutatior effects promoted by the uvrD::Tn5 and the ssb‐113 alleles was observed.

These results suggest a possible functional interactions between SSB and Helicase II in DNA repair and mutagenesis.
Bilanzierung des Lysingehaltes in Fermentationslösungen
Authors: Miosga N. , Hilliger M. , Römer W.
Published: February 2007

Balances of untreated and treated (heated 15 min at 80 °C) culture‐brothes of lysine were copared using both a modified furfural method and amino acid analyzer.
Purification and characterization of the extracellular glucoamylase from the yeast Trichosporon adeninovorans
Authors: Büttner R. , Bode R. , Birnbaum D.
Published: February 2007

The yeast Trichosporon adeninovorans secretes an amylase at a high rate if grown in a medium containing starch or maltose. The enzyme was purified 29‐fold by hydroxylapatite chromatography and gel filtration and characterized as a glucoamylase. The enzyme seems to be a glycoprotein with a molecular weight of 225,000. The optimal temperature for the glucoamylase activity was 60 to 70 °C in dependence on the substrate concentration. The enzyme displayed highest activity in a pH range of 4.0–5.5 In the absence of starch or maltose the thermal stability was low but in the presence of substrate a rapid increase of the enzyme stability was observed. The Km values of the enzyme were estimated to be 1.2 g/l for soluble starch and 4 g/l for maltose.
Induction of phenol assimilation in chemostat cultures of Candida maltosa L4
Authors: Hofmann K. H. , Vogt Ute
Published: February 2007

To investigate the induction of phenol hydroxylase and catechol 1,2‐dioxygenase in Candida maltosa L4 during chemostat cultivation, changes in the growth‐limiting substrate were carried out at different dilution rates.

No activity of phenol hydroxylase and catechol 1,2‐dioxygenase could be detected in the cells during chemostat cultivation of C. maltosa L4 under glucose limitation independent of the dilution rate. However, once the feed line was changed from glucose medium (sr = 28 mM) to a medium containing either phenol (sr = 28 mM) or a mixture of phenol (sr = 18 mM) and glucose (sr = 10 mM), both the phenol hydroxylase and the catechol 1,2‐dioxygenase were fully induced. After 5 hours at all dilution rates tested (D = 0.05 h−1, D = 0.11 h−1, and D = 0.2 h−1). In spite of this enzyme synthesis, the cells were washed out if C. maltosa L4 was shifted from glucose to phenol at a higher dilution rate than D = 0.05 h−1, probably due to accumulation of inhibiting concentrations of phenol in the medium and starvation of NADPH. If being shifted from glucose to a mixture of phenol and glucose, however, the cells reached a new steady state even at a higher dilution rate of D = 0.2 h−1.

The specific activity of phenol hydroxylase in crude extracts of C. maltosa L4 was nearly independent of the growth rate in the range D = 0.05 h−1 to D = 0.2 h−1 on both phenol and a mixture of phenol and glucose, respectively, as the growth‐limiting substrates. In contrast, catechol 1,2‐dioxygenase activity correlated with the growth rate when the cells were cultivated on phenol. In the presence of mixtures of phenol and glucose, the observed decrease of specific activity of this enzyme at a high dilution rate (D = 0.2 h−1) is possibly a result of repression by glucose or an glucose metabolite.
Routes of formaldehyde oxidation to CO2 in Acetobacter methanolicus MB58
Authors: Gründig M. W. , Babel W.
Published: February 2007

Methylotrophic bacteria which use hexulose‐6‐phosphate synthase for fixing formaldehyde are able to oxidize it cyclically via 6‐phosphogluconate. This also holds true for Acetobacter methanolicus MB58. Generally methylotrophic bacteria oxidize formaldehyde via formate to CO2. Up to now only the presence of a membrane‐bound, dye‐mediated formate dehydrogenase has been demonstrated in Acetobacter methanolicus MB58. In this paper evidence for the presence of an aldehyde dehydrogenase is provided which catalyzes the oxidation of formaldehyde by means of toluylene blue as an electron acceptor. Hence Acetobacter methanolicus MB58 possesses at least two routes for the dissimilation of formaldehyde to CO2.
Streptavidin assay by means of biotinylated actinophages
Authors: Fleck Werner F.
Published: February 2007

Using D‐biotinyl‐N‐hydroxysuccinimide ester, biotin was covalently attached to actinophage SLE 111. The chemically modified actinophage preparation (SLE 111‐BIO) was prevented from forming plaques by biotin‐binding proteins, such as streptavidin and avidin. The avidin concentration at 50% inactivation of biotinylated actinophages was 0.5 μg/ml. The streptavidin assay was useful as pre‐selection method during the screenig and improvement work with streptavidin‐producing microorganisms.
Subcellular organization of alkane oxidation in the yeast Candida maltosa
Authors: Mauersberger S. , Kärgel E. , Matyashova R. N. , Müller H.‐G.
Published: February 2007

After spheroplast lysis and differential centrifugation the alkane monooxygenase system consisting of cytochrome P‐450 and the NADPH‐cytochrome P‐450 reductase of alkane‐grown Candida maltosa cells is enriched in the microsomal fraction. This membrane fraction is nearly free of intact mitochondria (cytochrome oxidase) and peroxisomes (catalase), but contains considerable amounts of plasma membrane fractures (azide insensitive, vanadate‐sensitive Mg2+‐ATPase) as demonstrated by biochemical an electron microscopic examinations. By means of sucrose density gradient centrifugation it was possible to separate the cytochrome P‐450 containing membranes ( = 1,11 g/cm3) from the plasma membranes ( = 1,18 g/cm3). Therefore the cytochrome P‐450 alkane monooxygenase system is most likely localized in the endoplasmic reticulum of the yeast cells.

For the following enzymatic steps of terminal alkane oxidation to the corresponding fatty acid a quite different subcellular distribution was observed. The fatty alcohol oxidase and aldehyde dehydrogenase activities are mainly localized in the mitochondrial peroxisomal membrane fraction.

During the oxidation of n‐alkanes by yeast cells the fatty alcohol should be regarded as an intracellular transport from between the cytochrome P‐450 containing endoplasmic reticulum and the sites of its further oxidation in peroxisomes and mitochondria.
Regulation von Schlüsselenzymen der Biosynthese aromatischer Aminosäuren in Alkaloid‐bildenden Kulturen von Penicillium cyclopium w.
Authors: Schmauder H.‐P. , Roos W.
Published: February 2007

In Penicillium cyclopim w., phenylalanin and anthranilate are precursors of the benzodiazepine alkaloids cyclopenin and cyclopenol. The onset and increase of alkaloid biosynthesis in emerged cultures was paralleled by an increase of the in vitro activities of the precursor synthesizing enzymes DAHP synthase1), chorismate mutase, and anthranilate synthase as well as tryptophan synthase. This increase was most pronounced with the DAHP synthase and, therefore, enabled the cells to maintain a constant level of the “central” precursor, chorismate, in the course of alkaloid production. In contrast, the contents of phe, anthranilate as well as tyr and trp decreased with increasing rate of alkaloid synthesis, indicating that the supply of the immediate precursors did not fully compensate the drain towards alkaloid formation. The strongest decrease was seen with the anthranilate content, which was due to several control mechanisms: the increase of anthranilate consuming reactions prior to the anthranilate synthase, the higher capacity of the alternate. phe producing branch of the aromatic pathway, and the feedback inhibition by trp of anthranilate synthase. The formation of anthranilate most probably was the rate limiting step of alkaloid production.
Ultrastructure of Saccharomyces cerevisiae cells accumulating Golgi organelles
Authors: Svoboda Augustin , Nečas Oldřich
Published: February 2007

Restrictive phenotype of sec 7 mutant of Saccharomyces cerevisiae was examined by freezefracture electron microscopy. In accordance with previous findings (NOVICK et al. 1981) dictyosomes and middle‐size (200–600 nm) vesicles (BERKELEY bodies) were found to accumulate. Dictyosomes are formed by aggregated, flattened or dialted cisternae without associated secretory vesicles. After transfer to permissive conditions the dictyosomes disappear and are not detectable, just like in the wild type or in the permissive phenotype. Associated with the restrictive phenotype is an extended plasma membrane and tonoplasts with particlefree impressions.
Compartmentation of enzymes interconverting aclacinomycins in Streptomyces species AM 33352
Authors: Gräfe U. , Dornberger K. , Fleck W. F. , Freysoldt C.
Published: February 2007

The enzymatic interconversion of the aclacinomycins A (I), Y (II), and B (III) by Streptomyces spec. AM 33352/S 182 producing these aklavinone glycosides was investigated. The enzymes converting I to II and III, as well as vice versa, are located within different compartments separated by the cytoplasmic membrane.
Expression of the human interferon‐α1 gene under transcriptional and translational control of the speA gene
Authors: Laplace Frank , Hartmann Manfred , Klessen Christian , Tonew Marion , Malke Horst
Published: February 2007

The human gene for mature interferon‐α1 (IFN‐α1) was inserted in a new transcription‐translation fusion vector system based on the expression and secretion signals of the gene for type A streptococcal pyrogenic exotoxin, speA. As deduced from the known nucleotide sequences of the component elements, the encoded IFN‐α1 was a fusion protein carrying an N‐terminal extension of 17 amino acids. When inserted in appropriate vectors capable of replication in Escherichia coli, Bacillus subtilis and Streptococcus sanguis, this expression configuration directed the synthesis of antiviral activity in all 3 organisms, as judged by the cythopathic effect inhibition assay of Vesicular Stomatitis Virus. In E. coli JM101, IFN activity was found mainly in the cytoplasmic protein fraction whereas in the gram‐positive hosts, it was completely secreted into the culture medium.
Development of genetic maps of non‐conventional yeasts
Authors: Ogrydziak David M.
Published: February 2007

Numerous methods based on classical genetics have been developed for the genetic mapping of yeasts. Recombinant DNA technology and technology for electrophoretic separation of chromosomes make new approaches possible. The state‐of‐the‐art in genetic mapping of Saccharomyces cerevisiae will be briefly reviewed. Then the availability and application of genetic mapping methods to non‐conventional yeasts will be surveyed. Development of the genetic maps of the asexual diploid Candida albicans and of the heterothallic yeast Yarrowia lipolytica will be discussed in more detail.
Replication and recombination in gene establishment in non‐Saccharomyces yeasts
Authors: Oliver Stephen G.
Published: February 2007

A brief review is given on the establishment of recombinant DNA technology for non‐conventional yeasts. The availability of DNA delivery systems, selectable markers for identification of transformants, and the means of replicating and amplifying the recombinant DNA are discussed. Some of the existing transformation systems among non‐conventional yeasts are explained.
A gene‐cloning system for Kluyveromyces lactis and isolation of a chromosomal gene required for killer toxin production
Authors: Chen X. J. , Wésolowski‐Louvel M. , Tanguy‐Rougeau C. , Bianchi M. M. , Fabiani L. , Saliola M. , Falcone C. , Frontali L. , Fukuhara H.
Published: February 2007

A transformation system derived from the circular plasmid pKD1 has been developed for Kluyveromyces lactis. The principle is essentially equivalent to that of the 2 μ/Saccharomyces cerevisiae transformation system. The main features of the system are presented. Using a pKD1‐based DNA bank of K. lactis, the KEX1 gene involved in the killer system was isolated by complementation.
Genetic control of Yarrowia lipolytica fatty acid synthetase biosynthesis and function
Authors: Schweizer Eckart , Köttig Hartmut , Regler Roger , Rottner Gerhard
Published: February 2007

Yarrowia lipolytica, like other lower fungi, has a fatty acid synthetase complex (FAS) with an α6β6 molecular structure. Both subunits are multifunctional proteins each with a molecular weight of more then 200000 daltons. A collection of FAS‐deficient2) Y. lipolytica mutants was isolated and characterized by both genetic complementation and enzyme activity measurements. It was found that the three acyl transferases (acetyl‐, malonyl‐ and palmityl‐transacylation) together with the enoyl reductase domain are located on subunit β and, therefore, are encoded by the gene locus FAS1. β‐Ketoacyl reductase, β‐ketoacyl synthase and acyl carrier protein functions are part of the FAS2‐encoded subunit α. Thus, the functional organization of FAS1 and FAS2 is identical in both yeasts, Saccharomyces cerevisiae and Yarrowia lipolytica. Nevertheless, the two yeasts differ significantly with respect to the intragenic complementation characteristics of fas1 and fas2 mutants. This finding is discussed in terms of a specific inter‐or intramolecular reaction mechanism within the oligomeric FAS complex. The pentafunctional Y. lipolytica FAS1 gene was isolated from a λgtll expression library using polyclonal antisera against the purified FAS complex. At present, sequencing of FAS1, which is more than 5 kilobases long, is almost completed. Available data indicate approx. 60 percent sequence homology together with an identical order of catalytic domains within subunit β of the two yeasts, Y. lipolytica and S. cerevisiae.
Genetic manipulation of non‐conventional yeasts by conventional and non‐conventional methods
Authors: Spencer J. F. T. , Spencer Dorothy M. , Reynolds Nicola
Published: February 2007

In recent years, yeasts other than those belonging to the species Saccharomyces cerevisiae and Schizosaccharomyces pombe have become increasingly important in industrial processes. Species such as Pichia stipitis, Hansenula polymorpha, Zygosaccharomyces rouxii, Saccharomyces exiguus, Torulaspora delbrueckii, Yarrowia lipolytica and others whose perfect stage is known, can be manipulated genetically by classical methods, but those belonging to the genera Candida (C. utilis, C. tropicalis, C. bombicola, C. zeylanoides, C. boidinii, etc.), Brettanomyces, Cryptococcus, Rhodotorula, and others of the different form genera, cannot be treated in this way. Some, such as Schwanniomyces and Debaryomyces spp., which have a perfect stage, are still difficult to manipulate by conventional means. Genetic manipulation of these yeasts can be approached from two points of view; the first involving improvement of strains by cross‐breeding within one species, and the second, the introduction of desirable genes from unrelated species and even from plants or animals.

Two techniques are available for construction of industrially‐useful strains from these yeasts: protoplast fusion and transformation with chimaeric plasmids containing the gene(s) it is desired to introduce into the recipient strain. The methods for the latter procedure are well known but can be laborious and time‐consuming, especially if it is desired to introduce genes from plant or animal sources for production of enzymes, hormones, vaccines and similar products. Protoplast fusion is a simple technique which can be utilized in most laboratories and used for construction of improved yeast strains for brewing, baking, ethanol production and wine‐making, either by the fusion of desirable strains of the same species which do not sporulate, or by introduction of genes from non‐Saccharomyces species. Methods for fusion of species from different genera and isolation of the desired hybrids have been improved considerably in recent years. We have developed a method for isolation of strains carrying the desired genes by fusing a non‐Saccharomyces species with an auxotrophic strain of Saccharomces cerevisiae and selecting hybrids having the desired characteristics on appropriate media, after which the genes are transferred to the industrial strain by rare‐mating, repeated protoplast fusion, or classical mating as required. The advantages and limitations of the method are under investigation.
Identification by heteroduplex analysis of an invertible element (Min) common among IncM group plasmids
Authors: Karste Gunter , Adler Klaus , Klaus Siegfried , Tschäpe Helmut
Published: February 2007

The analysis of heteroduplexes between EcoRI digested DNA derived from IncM plasmids in the transfer‐off and in the transfer‐on state revealed an internal loop of about 1 kbp on a distinct large EcoRI fragment. The presence of an invertible element (Min) is suggested which enables the formation of conjugative piliat 30 °C, but switches off the pilus formation at 37 °C incubation temperature.
DNA fingerprinting of conjugative plasmids incompatible with R6K (IncX)
Authors: Prager Rita , Tietze Erhard , Tschäpe Helmut
Published: February 2007

14 conjugative plasmids originated from different bacterial hosts and geographical sources were identified as members of the incompatibility group IncX with R6K as the reference plasmid. In spite of their close genetic relatedness (transfer and incompatibility properties), their molecular sizes ranged between 39 and 77 kb and DNA fingerprinting with endonucleases such as EcoRI, EcoRV, BamHI, Bg/I, Bg/II, PstI and Sa/I revealed a great variety of fragment patterns.
Radiorespirometric analysis of glucose dissimilation in Rhodococcus sp. An 117 and An 213
Authors: Schukat B. , Janke D.
Published: February 2007

Radiorespirometric experiments were carried out by incubating various types of resting cells of either Rhodococcus sp. An 117 or Rhodococcus sp. An 213 under aerobic conditions with differentially labelled glucose. The results obtained indicate the constitutive nature of glucose catabolism in both these strains, i.e. there was no principle shift in glucose dissimilation during cell growth with different carbon substrates. On the basis of the observed ratios of percentage (cumulative) 14CO2‐formation from (6‐14C)glucose and (1‐14)glucose, the glycolytic EMP‐pathway was calculated to be the predominant catabolic route being operative to an extent of about 95% (strain An 117) and 78% (strain An 213).
The role of iron in the growth and hemolysin (Streptolysin S) production in Streptococcus pyogenes
Authors: Griffiths Bertie B. , McClain Oza
Published: February 2007

Four strains of Streptococcus pyogenes were propagated at 37 °C in a reduced iron medium supplemented with Fe3+‐citrate to give concentrations of 1 through 11 micrograms per milliliter, in order to observe the effects of iron on growth and on the vitro production of Streptolysin S. Both growth and hemolysin production were observed to be influenced by medium iron concentration of which 1.2 μg per ml of iron was critical. Hemolysin was produced during the exponential phase of the growth cycle with maximum yield as the organism entered the stationary phase. Hemolytic activity (which was accepted as the ability of the hemolysin to lyse sheep erythrocytes) fell below detectable levels as the organisms entered fully into the stationary phase (9–10 hours post incubation). Serum (bovine, human, chicken) was observed to have a high stabilizing effect on the hemolysin.
Einsatz der Phenol‐Wasser‐Extraktion zur Isolierung des gruppenspezifischen Polysaccharidkomplexes aus B‐Streptokokken
Authors: Mehl M. , Starke R. , Möckel Claudia , Presber W.
Published: February 2007

The group specific polysaccharide of Group B streptococci was isolated either by means of phenol‐water extraction or by Lancefield extraction procedures. Two groups of rabbits were immunized with these substances to induce polyclonal antibodies. The phenol‐water extract induced antisera had a significantly higher titer against B streptococci than against A‐, D‐ and G streptococci in the agglutination reaction. The B‐specific titers in rabbits immunized with phenol‐water extract were significantly higher than those obtained in the rabbits immunized with Lancefield extract.

In counter immunoelectrophoresis, only the antisera prepared by immunization with phenol‐water extract reacted with standard antigen from group B streptococci. The serological specificity of the phenolwater extract antigen isolated from B streptococci was confirmed by counterimmunoelectrophoresis. The antigen was a heterologous fraction with a molecular mass of 8 × 104 − 2 × 106 Dalton.
Transfer of Rhizobium leguminosarum Sym plasmids to R. meliloti and stability of resident and transferred plasmids
Authors: Miksch G. , Lentzsch P.
Published: February 2007

The recombinant symbiotic (Sym) plasmids pIJ1008 and pIJ1019 and the natural Sym plasmid pJB5JI of Rhizobium leguminosarum were transferred to derivatives of the Rhizobium meliloti strain Rm41 and to local wild strains of R. meliloti to investigate their transfer frequency and stability. Transfer to the latter strains was only successful through two‐step conjugations, i.e. transfer to a compatible R. meliloti strain followed by transfer to wild strains. The transferred Sym plasmids and the resident plasmids of R. meliloti with a molecular weight up to approximately 300 Md showed instability, resulting in the elimination of the latter, whereas the R. meliloti megaplasmids and their symbiotic properties were maintained. The natural plasmid pJB5JI was stable in free living transconjugants as well as those in symbiosis with alfalfa or pea. The two recombinant Sym plasmids showed deletions or structural changes dependending on the genotype of the recipient and the transferred plasmids. During symbiosis these plasmids may be further deleted or completely eliminated. The consequences for gene transfer programs are discussed in the paper.
Whole cell immobilization of D‐glucose isomerase enzyme on glass support
Authors: Shukla G. L. , Prabhu K. A.
Published: February 2007

Whole cell immobilization of Lactobacillus sp. cells for D‐glucose isomerase activity was done by taking well washed cell slurries of bacteria, coating them on rough surfaces of glass rods or glass slides, drying them at 50 °C to 55 °C under infra red lamp and finaly treating with polyvinyl alcohol. The immobilized glucose isomerase activity of cells showed remarkable change in pH optimum, thermal stability, Km and Vmax values as compared to free enzyme of cells. The immobilized enzyme system was employed in the conversion of glucose to fructose using concentrates of amylase‐treated corn starch and cellulase‐treated bagasse cellulose.
Experimentelle Untersuchungen zur in vitro‐IFN‐Induktion durch verschiedene Polynucleotide in humanen Zellkultur‐Systemen
Authors: Glück B. , Meister W.‐V. , Witkowski W. , Stelzner A. , Hoffmann S.
Published: February 2007

Several polynucleotides were tested for interferon induction in comparison with the standard Poly (IC) in human diploid fibroblasts and in human leukocyte suspensions.

We received high IFN‐titre following superinduction of the polynucleotides in human fibroblasts.

These results show that under superinduction conditions partly 3 times more interferon is induced in comparison with the standard inductor Poly (IC).

The tested concentration of 10 μg/ml polynucleotides did not result in any IFN yields or only in very low ones in human leukocytes, which were only within the range of detectability.
Critical steps in degradation of chloroaromatics by rhodococci I. Initial enzyme reactions involved in catabolism of aniline, phenol and benzoate by Rhodococcus sp. An 117 and An 213
Authors: Janke D. , Al‐Mofarji T. , Straube G. , Schumann P. , Prauser H.
Published: February 2007

Two bacterial isolates (i.e. strains An 117 and An 213) capable of growing with aniline, phenol as well as benzoate as the sole carbon and energy source were studied with respect to (i) their taxonomic position, (ii) the enzyme reactions which initiate catabolism of the respective aromatic compounds, and (iii) the general type of regulation of the respective enzymes.

Both isolates were established to be representatives of the actinomycete‐genus Rhodococcus. Experiments with resting cells and cell‐free extracts, respectively, revealed that in the two strains under study catabolism of each of the unsubstituted aromatic compounds occurs via the β‐ketoadipate pathway (with catechol as the central metabolite) due to the action of inducible enzymes. Although being potent inducers of the ring‐cleaving catechol 1,2‐dioxygenase in strains An 117 and An 213, all of the monochlorinated derivatives of aniline, phenol and benzoate, respectively, failed to support cell growth of the organisms. Cis, cis‐muconic acid proved to be non‐metabolizable by resting An 117 and An 213 cells, although substantial (inducible) muconate cycloisomerase activity was detectable in crude extracts prepared from the respective cell preparations. NADPH‐depending phenol hydroxylase activity could be demonstrated in crude extracts from phenol‐grown An 117 and An 213 cells. Evidence is presented that in both Rhodococcus strains under study substantial de novo synthesis of at least the initial aromatics‐oxygenating enzymes can be induced by phenol and aniline, respectively, even in the presence of either succinate (An 117) or acetate (An 213) which are known to be ortho‐pathway catabolites.
Characterization of a thermosensitive mutant of Streptomyces hygroscopicus defective in both DNA and RNA syntheses
Authors: Süss F. , Frunder B. , Klaus S. , Noack D.
Published: February 2007

A stable temperature sensitive mutant of Streptomyces hygroscopicus JA6599 defective in both DNA and RNA syntheses is described. The mutant ts35 is characterized by an immediate stop of DNA synthesis and continued protein synthesis after transfer to restrictive temperature. The reinitiation of DNA synthesis begins immediately after a return to the permissive temperature. This kinetics of macromolecular synthesis at restrictive temperature appears to share similarities with a defect in the DNA elongation process, as described for Escherichia coli (CARL 1970, HANNA and CARL 1975).

The simultaneous stop of both DNA and RNA syntheses may be caused by an additional mutational event affecting also the RNA synthesis. The data were discussed with respect to similar results in E. coli.
Mycoflora of air‐conditioners dust from Riyadh, Saudi Arabia
Authors: Bagy M. M. K. , Gohar Y. M.
Published: February 2007

Using the hair baiting technique, 6 genera and 14 species were collected on SABOURAUD'S dextrose agar from 37 dust samples from air‐conditioners. The most common fungi were Chrysosporium tropicum, C. indicum, C. keratinophilum, Aspergillus flavus followed by Acremonium strictum and Scopulariopsis brevicaulis.

Using the dilution‐plate method, 26 genera and 52 species were collected from 37 dust samples on glucose‐(23 genera and 45 species) and cellulose‐(18 genera and 34 species) CZAPEK'S agar at 28 °C. The most prevalent species were Aspergillus niger, A. flavus, Penicillium chrysogenum, Stachybotrys chartarum, Ulocladium atrum, Mucor racemosus and Fusarium solani and A. niger, A. flavus, Trichoderma viride, P. chrysogenum, Ulocladium atrum, Chaetomium globosum, C. spirale, Stachybotrys chartarum and Mucor racemosus on the two media, respectively.
Regulation of metabolic branch points of aromatic amino acid biosynthesis in Pichia guilliermondii
Authors: Koll P. , Bode R. , Birnbaum D.
Published: February 2007

The regulatory properties of the enzymes involved in the aromatic amino acid biosynthesis of Pichia guilliermondii were investigated and compared with the regulatory pattern found in other yeast species. 3‐Deoxy‐D‐arabino‐heptulosonate‐7‐phosphate (DAHP) synthase, anthranilate synthase, chorismate mutase and prephenate dehydrogenase are key regulatory enzymes in P. guilliermondii. Two distinctly regulated isozymes of DAHP synthase, the initial pathway enzyme, which is inhibited by tyrosine or phenylalanine were separated by DEAE‐cellulose chromatography and were characterized. Tryptophan is an excellent feedback inhibitor of anthranilate synthase, the first definite step in tryptophan biosynthesis. There are two controlled enzymes within the specific synthesis of phenylalanine and tyrosine, chorismate mutase and prephenate dehydrogenase. Chorismate mutase exhibits a balanced allosteric responsivity to phenylalanine and tyrosine, when these are used as inhibitor; tryptophan acts as an allosteric activator. Tyrosine is an effective inhibitor of prephenate dehydrogenase, whereas the activity of prephenate dehydratase is not affected by any of the aromatic amino acids. The synthesis of the enzymes in the yeast was not repressed by any single exogenous aromatic amino acids, nor by combinations of the same.
Nachweis und Charakterisierung einer konstitutiven Lävansucrase und einer epigenetisch regulierten Saccharase in Pseudomonas syringae pv. phaseolicola
Authors: Sauerstein J. , Reuter G.
Published: February 2007

Pseudomonas syringae pv. phaseolicola, a plant pathogenic pseudomonad, possesses two sucrose‐splitting enzymes, a levansucrase and a sucrase. The levansucrase is found both extracellularly and intracellularly, and enzyme synthesis is independent of the carbon source. In addition to levansucrase, cells grown on sucrose contain a sucrase. The two sucrose‐splitting enzymes differ in their optimum pH value and optimum temperature as well as in their substrate specificities.
Calcium and the biological activities of two Streptomyces species isolated from the rhizosphere of soybean plants
Authors: Kamel Zeinat , Khalil Mary S. , Shalaby Ahmed M.
Published: February 2007

Careful examination of the characteristics of both organisms revealed that we are dealing with Streptomyces violaceochromogenes and Streptomyces glaucescens. Calcium chloride decreased the permeability of both organisms as indicated by the low total nitrogen content of their media compared to the controls. Small doses of calcium nitrate suppressed the permeability of S. violaceochromogenes and increased that of S. glaucescens whereas the larger doses were stimulatory for both organisms. Calcium nitrate had similar effects on S. violaceochromogenes only without affecting S. glaucescens. The stimulatory effects of calcium gradually faded with increased concentration. Calcium chloride increased the proteolytic activity in S. violaceochromogenes media; a phenomenon that was apparent in S. glaucescens media only in the case of the larger doses. Calcium nitrate suppressed the proteolytic activity in S. glaucescens media. The cellulolytic activity of both organisms was suppressed by calcium but amylases were initiated in S. glaucescens media. Those of S. violaceochromogenes were arrested with the lower levels of calcium but the larger doses restored or stimulated their activity.
Steroid transformations by a strain of Arthrobacter oxydans incapable of steroid ring degradation
Authors: Sarmah Utpal , Roy Monoj K. , Singh H. Devendra
Published: February 2007

Arthrobacter oxydans 317 which is able to bring about the complete degradation of β‐sitosterol was treated with acridine orange to obtain a plasmid cured strain Arthrobacter 317AL, incapable of producing steroid ring degradation. The strain was neither able to form 4‐androstene‐3,17‐dione(AD) from β‐sitosterol nor to convert AD to 1,4‐androstadiene‐3,17‐dione(ADD). It was, however, able to hydroxylate AD and ADD at the C‐17 position to form testosterone and 1,4‐androstadiene‐17β‐ol‐3‐one respectively. The strain could grow on β‐sitosterol presumably utilizing the degradation products of the sterol side chain. Partial degradation of the β‐sitosterol side chain was demonstrated by the isolation of 27‐norcholest‐4‐en‐3,24‐dione, a metabolic product of the side chain degradation. The existence of metabolic blocks in a further degradation of the side chain to AD, in 1,2‐dehydrogenation and 9α‐hydroxylation of the steroid ring structure was postulated.
Altered control of chorismate mutase leads to tryptophan auxotrophy in Pichia guilliermondii
Authors: Bode R. , Koll P. , Prahl N. , Birnbaum D.
Published: February 2007

We isolated a tryptophan auxotrophic mutant strain, PK101, of Pichia guilliermondii. Its auxotrophy is not caused by a defect in any of the tryptophan biosynthetic enzymes, but its chorismate mutase, an enzyme of the phenylalanine‐tyrosine biosynthesis, is changed. In comparison to the wild type chorismate mutase, the enzyme of PK101 is characterized by a complete loss of sensitivity to L‐phenylalanine inhibition and to a considerable loss of sensitivity to L‐tryptophan activation. Furthermore, the chorismate mutase activity of the mutant is more than 7‐fold higher in the absence of L‐tryptophan than in the wild type. The PK 101 enzyme is also changed in the pH optimum and in some kinetic constants. We found an increased intracellular pool of both phenylalanine and tyrosine, and a reduced content of tryptophan in the mutant cells. Our genetic data indicate that the mutant phenotype is dominant over the wild type.
Isolation and structure of 26‐deoxylaidlomycin, a new polyether antibiotic from Streptoverticillium olivoreticuli
Authors: Gräfe U. , Schlegel R. , Stengel C. , Ihn W. , Radics L.
Published: February 2007

26‐Deoxylaidlomycin (I, C37H61O11Na) was isolated together with its cometabolite laidlomycin (II) from the mycelium of Streptoverticillium olivoreticuli IMET 43782. Its structure was determined by high‐field 13C and 1H NMR, and MS spectral studies. The antibacterial activity of I against Bacillus subtilis ATCC 6633 was found to be approx. four times higher than that of laidlomycin (II).CALLING STATEMENT : magnified image.

The structure of 26‐deoxylaidlomycin (I: sodium salt, R1 = Na, R2 = H): III free acid: R1, R2 = H and laidlomycin (II, sodium salt: R1 = Na; R2 = OH).
Symbiotically defective histidine mutant of Rhizobium meliloti strain L5.30
Authors: Malek Wanda
Published: February 2007

Histidine auxotroph of Rhizobium meliloti strain L5.30 was isolated by nitrosoguanidine (NTG) mutagenesis. On alfalfa it formed ineffective nodules that contained only a few degenerating bacteroids inside large vacuoles but many starch granules. Prototrophic forms of this mutant (revertants and transductants) formed pink, effective nodules. Effective nodules were also induced by the His− mutant when histidine was supplied to the plant‐growth medium; this supported the supposition of a causal relationship between histidine auxotrophy and ineffectivity in the R. meliloti strain L5.30.

The histidine mutation of the strain studied was mapped onto the chromosome of R. meliloti by transduction near earlier localized cys‐246 auxotrophic mutation (4.4% of cotransduction).
Storage temperature and viability of sporangiospores of potentially human pathogenic species of Rhizomucor from Nigerian tobacco
Authors: Ogundero V. W. , Aina J. O.
Published: February 2007

The effects of temperature on storage and viability of asexual spores of Rhizomucor pusillus (LINDT) SCHIPPER and Rhizomucor miehei (COONEY and EMERSON) SCHIPPER were studied. An optimal germination temperature of 35 °C was recorded for both species with good results obtained around 40 °C. On prolonged storage of the spores at various temperatures (‐19 °C, 4 °C, 30 °C, 37 °C), the best results were obtained at 4 °C and 30 °C. Very rapid losses in viability of the spores of both fungi occurred at −19°C reaching a maximum of 68% and 51%, respectively, for R. pusillus and R. miehei after 6 months of storage.

Continuous exposure of the spores to 68 °C led to rapid losses of viability of up to 100% for those of R. pusillus after 40 min exposure. Sporangiospores of R. miehei showed more gradual losses on exposure to 68 °C.

The potential health hazards which the presence of these fungi on tobacco products pose to man are discussed.
Einsatz der Fermenter‐Dialyse‐Kultur zur Züchtung kapseltragender Bakterien mit klinischer Bedeutung
Authors: Starke Roland , Mehl Michael , Möckel Claudia , Grunow Roland , Montag Thomas , von Baehr Rüdiger , Schmidt Gerhard
Published: February 2007

For mass cultivation of group B streptococci (B‐III and B‐variant streptococci), a fermenter dialysis culture technique is described and compared to conventional shaking culture and fermenter batch culture techniques.

The influence of two kinds of cultivation media on the bacterial yield is demonstrated.

The growth rate of the bacteria and the yield of the microbes is higher in modified POPE medium than that observed with Nährbouillon I.

The type‐specific polysaccharide of B‐III‐streptococci prepared by phenol‐water extraction followed by gelchromatography can be used as a screening antigen for the production of monoclonal antibodies against B‐III‐streptococci.
A further characterization of alanine dehydrogenase from Streptomyces aureofaciens
Authors: Vančurová Ivana , Vančura Aleš , Volc Jindřich , Neužil Jiří , Běhal Vladislav
Published: February 2007

Homogeneous alanine dehydrogenase isolated from Streptomyces aureofaciens, a producer of tetracycline, was characterized from the point of its molecular and catalytic properties. Using analytical ultracentrifugation the molecular weight of alanine dehydrogenase was found to be 198,000. The enzyme could use as cofactors apart from NAD+ also l,N6‐etheno‐NAD+, 3‐acetylpyridine‐NAD+, deamino‐NAD+ and nicotinamide guanine dinucleotide. The enzyme activity in the direction of oxidative deamination was not affected by the addition of nonsubstrate amino acids, however, it was sensitive to inhibitors of SH‐groups. Reductive amination of pyruvate was inhibited by L‐alanine, L‐serine and D‐alanine. The inhibition by L‐alanine and L‐serine was uncompetitive with respect to NADH and noncompetitive with regard to pyruvate and ammonium ions.
An efficient method for producing and purifying gramme quantities of T‐2 toxin
Authors: Lepom Peter , Baath Helga
Published: February 2007

A simple procedure was developed for the laboratory production and purification of gramme quantities of T‐2 toxin. After growing at 22 °C on rice for two weeks, Fusarium sporotrichioides T‐21 produced average T‐2 toxin concentrations of 1309 mg/kg and as much as 1000 mg of crystalline product were recovered. The method described avoids long‐term, low temperature incubations. Crude culture extracts were rapidly purified in two steps by column chromatography on silica gel. The purity of the crystallized product was verified by thin‐layer chromatography using various spray reagents for detection.
Chemische Charakterisierung des Escherichia coli K 1 Kapselpolysaccharides
Authors: Mehl Michael , Starke Roland , Kissig Bettina , Grunow Roland , Jahn Siegbert , Schmidt Gerhard , von Baehr Ruediger
Published: February 2007

The exact chemical characterization of the prepared Escherichia coli K 1 capsule polysaccharide is necessary and a prerequisite for using this antigen as a screening antigen in the production of monoclonal anti‐K 1‐antibodies.

The K 1‐antigen, prepared by phenol‐water‐extraction, was analyzed by protein, RNA, and neuraminic acid determination. An addition, the antigen was subjected to elementary analysis, infrared‐ and 13C‐NMR‐spectroscopy, and gelchromatography.

After testing the serological specificity, the K 1‐antigen was identified as a high molecular polyneuraminic acid.
Untersuchungen über das Vorkommen von Lävansucrase und Saccharase bei Pathovarietäten von Pseudomonas syringae und eng verwandten nicht phytopathogenen Pseudomonaden
Authors: Sauerstein J. , Reuter G.
Published: February 2007

Like P. syringae pv. phaseolicola, other pathovarieties of the Pseudomonas syringae group (P. syringae pv. glycinae, P. syringae pv. syringae, P. syringae pv. tabaci, and P. syringae pv. tomato) possess two sucrose splitting enzymes, a constitutive levansucrase found both extracellularly and cellularly, and a cellular sucrase, the synthesis of which is regulated differently. In P. fluorescens, a closely related saprophytic pseudomonad, only a levansucrase was found.
Keratinophilic fungi from the duck nails in Egypt
Authors: Abdel‐Gawad K. M. , Moharram A. M.
Published: February 2007

The mycoflora of one hundred and sixty of duck nail samples, collected from the duck Farm, Faculty of Agriculture, Assiut University, were examined. Using the soil plate technique and SABOURAUD'S dextrose agar, thirty six species appertaining to twenty genera of keratinophilic fungi were isolated. Chrysosporium was the genus most frequently isolated (50% of the samples). Aspergillus and Penicillium occurred in low incidences (13.1 and 12.5% of total samples). Trichophyton rubrum was found to colonize few of the duck nail samples (2.5%) as well as some other fungal species previously reported as pathogenic to man and animals (Aspergillus fumigatus, Scopulariopsis brevicaulis and Paecilomyces lilacinus).
Antifungal activity of dihydrodioscorine extracted from a wild variety of Dioscorea bulbifera L
Authors: Adeleye Adetoun , Ikotun T.
Published: February 2007

The bulbils and tubers of a wild variety of Dioscorea bulbifera L. contained an alkaloid, dihydrodioscorine. When crystallized in its hydrochloride form and incorporated into potato dextrose agar at a final concentration of 0.1%, it was found to slow down the rate of growth of five plant pathogenic fungi namely: Sclerotium rolfsii, Curvularia lunata, Fusarium moniliforme, Macrophomina phaseolina and Botryodiplodia theobromae. Also sclerotia formation in S. rolfsii was delayed and the number was reduced. Conidia formation in C. lunata and F. moniliforme was also delayed and reduced but pycnidia formation in M. phaseolina and B. theobromae was not affected. There was no significant difference between the rate of growth of the fungi on PDA incorporated with 0.01% final concentration of dihydrodioscorine and on control plates. Abbreviations: PDA = potato dextrose agar, D.D. = dihydrodioscorine dihydrochloride.
Biosynthesis of anthracyclinones: Biotransformation of aklaviketone
Authors: Eckardt K. , Schumann G. , Wagner C. , Stengel C. , Ihn W. , Novák J. , Tresselt D.
Published: February 2007

In a series of feeding experiments, aklaviketone was added to cultures of the blocked mutants Streptomyces galilaeus S 727, S. peucetius var. caesius 21/8 and S. griseus 956/2. The compound was transformed to give cinerubin A or ϵ‐rhodomycinone. The results provide further evidence for the proposed biosynthetic pathway leading from aklanonic acid via aklaviketone to aklavinone and related anthracyclinones.
Critical steps in degradation of chloroaromatics by rhodococci III. Isolation and identification of accumulating intermediates and deadend products
Authors: Ihn W. , Janke D. , Tresselt D.
Published: February 2007

Pre‐adapted resting cells of different aromatics‐utilizing Rhodococcus strains readily cometabolized various monochloroaromatic non‐growth substrates (i.e. 2‐chloroaniline, 3‐chloroaniline, 3‐chlorophenol, 4‐chloro‐phenol and/or 3‐chlorobenzoic acid). Certain intermediates (i.e. 3‐ or 4‐chlorocatechol) and/or dead‐end products (i.e. 2‐chloro‐cis,cis‐muconic acid or cis‐4‐carboxymethylene‐but‐2‐en‐4‐olide) were isolated in preparative amounts from the respective incubation media and identified by chemical and spectroscopic (UV/VIS, IR, MS, 1H‐NMR) analysis.