bluuebunny/crossref_metadata_2025_split huggingface dataset:
Production of deoxynivalenol and zearalenone by isolates of Fusarium graminearum Schw
Authors: Megalla S. E. , Bennett G. A. , Ellis J. J. , Shotwell O. I. 
Published: February 2007

AbstractThe production of deoxynivalenol (DONI) on rice, corn, wheat, and barley grains by Fusarium graminearum Schw. NRRL 5883 was investigated. Highest yields (91.9–202 ppm) were obtained on rice; yields on the other substrates were: corn (34.1–84.5 ppm), wheat (3.6–24.4 ppm), and barley (0–6.6 ppm). Fifty isolates of Fusarium from corn inoculated in the field in 1979 with a mixture of strains of F. graminearum, originally collected from corn plants infected with stalk rot, were tested for DONI production on corn. Twenty of these were also tested for zearalenone production. One isolate produced more than 200 ppm DONI, 13 produced 20–50 ppm, 17 produce 10–20 ppm, and the rest produced less than 10 ppm. The only isolate that did not produce DONI was not identified as F. graminearum. All 20 isolates tested produced zearalenone; 18 produced higher levels of zearalenone (15.4–369 ppm) than of DONI. The other 2 isolates formed essentially the same levels of zearalenone and DONI‐37 and 30 ppm, and 15 and 16 ppm, respectively.
Differential sensitivity of three cyanobacteria to the rice field herbicide Machete
Authors: Pandey K. D. , Kashyap A. K. 
Published: February 2007

AbstractThe effect of the rice field herbicide Machete (2‐chloro‐2′6′‐diethyl‐N‐(Butoxymethyl)acetanilide) on the growth and cell composition of Anacystis nidulans, Nostoc muscorum and Anabaena doliolum was investigated. Growth of these cyanobacteria was completely inhibited at 2.5, 5.0 and 20 μg/ml, respectively, while a slight stimulation of growth was observed at lower concentrations. Stimulation of cyanobacterial growth in the presence of low concentrations of Machete was associated with an increase in the cellular levels of phycobilins and RNA while there was little impact on the levels of chlorophyll a and DNA. Photosynthetic pigments were degraded at lethal concentrations. The toxicity of the herbicide towards N. muscorum and A. doliolum could be reversed by supplementing the growth medium with either nitrate, nitrite or ammonia. This did not apply for A. nidulans. It is suggested that Machete inhibited nitrogen fixation in the former two strains while availability of nutrients was affected in the latter strain. In either case death of the organisms was most likely due to nitrogen starvation.
Adhesion and phagocytosis of Staphylococcus aureus L‐forms
Authors: Schmitt‐Slomska J. , Michailova L. , Ivanova E. , Toshkov As. 
Published: February 2007

AbstractElectron microscopical investigations on in vitro and in vivo interactions of normal Staphylococcus aureus cells with rat peritoneal macrophages showed that these bacteria were rapidly endocytosed and digested even in the absence of specific antibodies. In contrast to the parental strains oxacilin‐induced and stable variante lacking a cell wall (L‐forms) were ingested without subsequent formation of phagolysomes and digestive vacuoles. The intracytoplasmic L‐form bodies retained their characteristic ultrastructure, i. e. no visible alterations occurred.Some morphological aspects of the L‐forms and their persistence in macrophages 7 days after intraperitoneal administration of L‐form to rats, suggest the possibility of their intracellular survival.
Spread of plasmid‐mediated nourseothricin resistance due to antibiotic use in animal husbandry
Authors: Hummel Ruth , Tschäpe H. , Witte W. 
Published: February 2007

AbstractAfter using of the streptothricin antibiotic nourseothricin in animal husbandry for growth promotion, plasmid‐borne resistance to streptothricin could be observed in E. coli from nourseothricin fed pigs, from emploees in pig farms and from their family members. Moreover, streptothricin resistance plasmids also occurred in E. coli of man without any contact to pig farms (gut flora and even urinary tract infections). However, these individuals live in villages and towns of the territory where nourseothricin was applied to pigs. Similar streptothricin resistance plasmids belonging to different incompatibility groups were found in both E. coli from pigs and E. coli from human beings. As no coselection of resistance to drugs indispensable for therapeutic use in man was observed, the application of nourseothricin in animal husbandry has not clinical implication for human medicine yet. Nevertheless, this problem remains under further investigation.
Localization of alkaline phosphatase in Streptomyces noursei
Authors: Kretschmer S. 
Published: February 2007

AbstractAlkaline phosphatase activity appeared in Streptomyces noursei strain IMET 43 716 when cultures were shifted to phosphate limitation. By using p‐nitrophenylphosphate as substrate, the activity detected at pH 9.4 was cell‐bound, as long as young mycelia were studied. Supernatant fluids of the cultures were only active, if partial mycelial lysis had taken place after incubation for several days under the influence of shear forces.After cytochemical staining the phosphatase reaction products were microscopically visible as grains distributed rather homogeneously within the hyphal lumen. The frequency of grains was correlated to the rate of nourseothricin production. Electron microscopy of thin sections showed the phosphatase reaction products to be only present in the cytoplasm.
Die mikrobiologische Synthese von Gibberellinen
Authors: Brückner B. , Blechschmidt D. 
Published: February 2007

AbstractThe present review deals with some essential aspects regarding to the microbial gibberellin biosynthesis during the last 10 to 15 years.After a brief historical outline some gibberellins resp. gibberellin‐like substances producing microorganisms (e. g. fungi, bacteria) are presented of which the ability to produce these compounds recently was published. In addition techniques to obtain mutants from the fungus Gibberella fujikuroi by means of physical and chemical methods are described. A further topic of the survey is dedicated to the biosynthetic pathway of gibberellins in the fungus Gibberella fujikuroi as well as the regulation of this biosynthetic route. In this connection especially the dependence of the biosynthesis on environmental factors (e. g. role of various carbon and nitrogen sources in the medium and their relation to each other) are demonstrated.Also a possible role of the gibberellins for the producing fungus itself is discussed.Finally, new fields of application for gibberellic acid and the gibberellins GA4 and GA7 (e. g. animal production, pharmaceutical industry) are presented.
Ultracytochemical localization of aldehyde dehydrogenase in Acinetobacter calcoaceticus
Authors: Sorger H. , Aurich H. , Fricke B. , Vořišek J. 
Published: February 2007

AbstractA membrane‐bound aldehyde dehydrogenase is induced in Acinetobacter calcoaceticus grown on aliphatic hydrocarbons as sole carbon source. This enzyme is NADP‐dependent and is able to oxidize medium‐ and long‐chain aliphatic aldehydes to their corresponding fatty acids. Electron micrographs of sectioned alkane‐adapted bacteria showed hydrocarbon inclusions in the cytoplasmic matrix. The cytochemical phenazine methosulphate‐tetranitro tetrazolium blue capture reaction allowed to localize the activity of the aldehyde dehydrogenase near the surface of these inclusions. At the same location we also found a NADPH tetrazolium‐reducing activity.
Zum Vorkommen von Hop‐22(29)‐en in Acetobacter methanolicus IMET B 346
Authors: Vier B. , Voigt B. 
Published: February 2007

AbstractA hydrocarbon was isolated from a lipid extract of Acetobacter methanolicus IMET B 346 (carbon source: methanol) and identified as hop‐22(29)‐ene.
Construction of bacterial strains with novel degradative capabilities for chloroaromatics
Authors: Reineke W. 
Published: February 2007

AbstractBiodegradation of most naturally occurring compounds is relatively fast, since microorganisms have evolved appropriate enzyme systems. However, biodegradation is less likely in the case of man‐made compounds like haloaromatics, which have structural features rarely or never encountered in natural products.One strategy to develop new metabolic activities for novel compounds by strains of microorganisms is by the alteration of their existing genetic information. The present paper summarizes results of studies where the degradation capabilities of bacteria were expanded by genetic material from external sources either by natural exchange or by cloning procedures.
Codon usage in streptococci
Authors: Malke Horst 
Published: February 2007

AbstractCodon usage was analysed for 14 streptococcal genes or significant open reading frames and found to be different from that in Escherichia coli and Bacillus subtilis. In particular, the preferred use of WWT codons over WWC was inconsistent with the rule of optimal codon‐anticodon interaction energy. On the other hand, for SSTC codons, adherence to this rule was better in streptococci than in E. coli. A preliminary codon bias table generated with the Pustell computer program for the analysed streptococcal genes may prove useful for the detection of protein coding regions in newly sequenced DN As from both streptococci and staphylococci.
Crown rot fungi of Nigerian bananas cv. Robusta and the effects of benomyl on their exo‐enzymes
Authors: Ogundero V. W. 
Published: February 2007

AbstractEight species of fungi were consistently obtained from crown rots of Nigerian bananas cv. Robusta. The predominant species were Botryodiplodia theobromae PAT. and Colletotrichum musae (BERK. & CURT) VON ARX. Others include: Ceratocystis paradoxa (DADE) C. MOREAU, Fusarium solani (MART.) SACC., Fusarium roseum SAYD. & HANS, Fusarium moliniformae SHELDON, Fusarium oxysporum SCHLECHT and Verticillum theobromae (TURC.) MASON & HUGHES. Growth‐temperature relations showed that B. theobromae and C. musae grew best at 30 °C within the 8‐day incubation period. Both fungal species produced extracellularly, amylases, pectin (methyl) esterase and CM‐cellulases. The synthesis of these enzymes was completely inhibited by the presence of the fungicide benomyl at concentrations of 200 ppm and above in the growth medium. At lower concentrations (50–150 ppm), pectin esterase and CM‐cellulase production was also suppressed while amylases were produced in measurable amounts.
The survival of propagules of Macrophomina phaseoli and Diplodia maydis in Nigerian soils
Authors: Durojaiye J. A. , Ikotun T. , Fajemisin J. M. 
Published: February 2007

AbstractWeekly isolations from sterile and unsterile soils artificially inoculated with Macrophomina phaseoli and Diplodia maydis showed a decline in numbers of the propagules of these pathogens. Sclerotia of M. phaseoli and spores of D. maydis could not be recovered either on dilution plate or on soil plates after four weeks of inoculation of unsterile soil and after fifteen weeks for D. maydis and twenty‐five weeks for M. phaseoli in sterile soil. In unsterile soil, sclerotia‐like structures were observed with the aid of a light microscope up to the tenth week after soil inoculation by the flotation technique but their viability could not be determined due to active parasitization by Penicillium sp. and Trichoderma sp. The high number of these hyperparasites/g of soil may be responsible for the non‐detection of these pathogens in soils of some maize‐growing states in Nigeria, as well as a reduction in their longevity in soil. It thus seems, from this study, that the host tissue is the site of survival of propagules of these pathogens from one season to another.
Hemagglutinating activity in phytopathogenic bacteria surface compounds
Authors: Serra M. Teresa , Castresana M. Carmen , Tejerina Genoveva 
Published: February 2007

AbstractExtracellular 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

AbstractOut 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

AbstractThe 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

AbstractResident 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

AbstractWe 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.
Purification and characterization of the extracellular glucoamylase from the yeast Trichosporon adeninovorans
Authors: Büttner R. , Bode R. , Birnbaum D. 
Published: February 2007

AbstractThe 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

AbstractTo 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

AbstractMethylotrophic 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

AbstractUsing 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

AbstractAfter 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

AbstractIn 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.