bluuebunny/crossref_metadata_2025_split huggingface dataset:
Keratinophilic and saprophytic fungi isolated from students' nails in Egypt
Authors: Abdel‐Hafez A. I. I. , El‐Sharouny H. M. M. 
Published: February 2007

AbstractIn order to determine the presence of dermatophytes and saprophytes in healthy toe and finger nails, 120 students (60 male and 60 female) from preparatory schools at Sohag Governorate (Upper Egypt) were studied. 54 species in addition to 3 varieties belonging to 17 genera were isolated. Six species of true dermatophytes were collected:Microsporum audouiniivar.rivalieri, M. cookei, Trichophyton mentagrophytes, T. simii, T. terrestreandT. verrucosum. Chrysosporium, a well‐known keratinophilic genus, was prevalent and represented by 7 species (C. asperatum, C. indicum, C. keratinophilum, C. luteum, C. pannorum, C. tropicumandChrysosporiumstate ofThielavia sepedonium). The commonest saprophytes in order of frequency were members of the generaAspergillus, Penicillium, Alternaria, Scopulariopsis, Fusarium, Paecilomyces, Chaetomium, Syncephalastrum, Mucor, RhizopusandAcremonium.
Algicidal properties of a bloom‐forming blue‐green alga, Oscillatoria sp.
Authors: Bagchi Suvendra Nath , Palod Archna , Chauhan Vikas Singh 
Published: February 2007

AbstractAn isolate of Oscillatoria from local eutrophic lake exhibits strong growth inhibitory effects, when phototrophically co‐cultured with a green alga and other blue‐green algae, including its natural predecessor. This effect was not observed on selected heterotrophic‐organisms. The characteristic interaction was also demonstrated with culture filtrates and cell‐free extracts, implying this effect to be due to some chemical released from Oscillatlia. From the mid‐log growth phase of the culture, a nonproteinaceous, moderately heat stable, and ether soluble metabolite was extracted by ether extraction. The primary site of the growth inhibitory substance (algicide) action appears to be the photosynthetic oxygen evolution, tested in Anacystis nidutlans. The characteristic algicidal substance may have a role, in nature, in species dominance.
Electroporation and expression of plasmid pBR322 in Klebsiella aerogenes NCTC 418 and plasmid pRK2501 in Pseudomonas putida CYM 318
Authors: Trevors J. T. 
Published: February 2007

AbstractKlebsiella aerogenes NCTC 418 and Pseudomonas putida CYM 318 were transformed via high‐voltage electroporation with plasmids pBR322 and pRK2501, respectively. The number of transformants obtained was dependent on the applied voltage, capacitance, and cell recovery procedure. For example, 7.87 × 104 transformants/μg DNA were obtained at 2500 V, 25 μF when K. aerogenes cells were electroporated with pBR322 DNA. A lower voltage (1500) and capacitance (3 μF) yielded 2.4 × 103 transformants/μg DNA. P. putida CYM 318 required a 24 h outgrowth period to assist in the recovery of transformants containing pRK2501. Electroporation may be a useful protocol to transform bacterial strains that are not easily transformed by traditional methods.
Ultrastructure of a Bacillus sp. strain KL8 isolated from indoor dust
Authors: Kari Merja , Rönkkö Reijo , Valtonen Anne , Phparinen Heli , Kukkonen Maini , Pöyry Tuija , Nohynek Liisa , Nurmiaho‐Lassila Eeva‐Liisa , Lounatmaa Kari 
Published: February 2007

AbstractA motile Gram‐positive bacterial strain (KL8) was isolated from indoor dust. It was identified by API‐test50 CHB as a species of Bacillus. This Bacillus sp. strain KL8 was described using different electron microscopic techniques: negative staining, thin sectioning, metal shadowing and freeze‐etching.An additional surface layer (S‐layer) was the outermost layer of the cell wall of this flagellated bacterium. The hexagonally arranged protein lattice covering the cells had a lattice constant about 9–10 nm, which falls in the same range as that of Bacillus anthracis.
Aktivitäten gluconeogenetischer Enzyme in der Hefe Candida maltosa bei Wachstum auf Glucose und Ethanol
Authors: Hofmann K. H. , Polnisch Elke 
Published: February 2007

AbstractThe activities of fructose‐1,6‐bisphosphatase, malate dehydrogenase and PEP carboxykinase were tested during discontinuous growth of the n‐alkane‐assimilating yeast Candida maltosa on glucose or ethanol.As expected, the highest activities of the enzymes were measured in the early log phase of growth on ethanol and the lowest in the early log phase of growth on glucose. However, the differences in the activities are much smaller than in Saccharomyces cerevisiae and other yeasts under similar conditions. Therefore, we conclude that catabolite repression does not play an essential role in the control of gluconeogenesis in Candida maltosa.
Anti‐staphylococcal serine proteinase and other serum factors in phagocytosis
Authors: Miedzobrodzki Jacek , Gorka Maria , Wasniowska Alicja , Tadeusiewicz Ryszard , Porwit‐Bobr Zofia 
Published: February 2007

AbstractThe interactions between polymorphonuclear cells (PMN), Staphylococcus saprophyticus cells and rabbit antibodies against Staphylococcus aureus V8 serine proteinase or normal rabbit serum proteins were investigated. The effect of opsonization on phagocystosis due to human peripheral polymorphonuclear cells was measured. The results were as follows: phagocystosis index values were relatively increased after the incubation of PMN cells with anti‐serine proteinase γ‐globulin serum fraction, anti‐serine proteinase IgG, non‐immunized rabbit serum or with complement.
L‐Carnitine metabolization and osmotic stress response in Escherichia coli
Authors: Jung Heinrich , Jung Kirsten , Kleber Hans‐Peter 
Published: February 2007

AbstractGrowth of Escherichia coli 044 K 74 in liquid medium of raised osmotic strength was stimulated by exogenous L‐carnitine, crotonobetaine and γ‐butyrobetaine, respectively. L‐Carnitine was accumulated within the cells in dependence on the salt concentration of the media. Osmotic stress during aerobic or anaerobic growth with glucose triggered the L‐carnitine uptake in E. coli 044 K 74 whereas L‐carnitine uptake by cells of this organism grown anaerobically on glycerol/fumarate was only slightly modified. Synthesis of the enzymes metabolizing L‐carnitine to γ‐butyrobetaine in glycerol/fumarate growing bacteria was found to be completely repressed by high NaCl‐concentrations. Together, these results indicate that most likely the L‐carnitine metabolization sequence does not play a role in osmoregulation in E. coli 044 K 74.
Biosynthesis of homoarginine and ornithine as precursors of the phytoeffector phaseolotoxin by the amidinotransfer from arginine to lysine catalyzed by an amidinotransferase in Pseudomonas syringae pv. phaseolicola
Authors: Márkisch U. , Reuter G. 
Published: February 2007

AbstractIn the phytopathogenic Pseudomonas syringae pv. phaseolicola an amidinotransferase was detected and characterized which catalyzes the amidinotransfer from arginine to lysine producing the phaseolotoxin precursors homoarginine and ornithine. The enzyme was purified 419‐fold by affinity chromatography on homoarginine‐Sepharose. It had an apparent mol. wt. of 200 000 and exhibited MICHAELIS‐MENTEN kinetics with Km 7.7 mM for arginine and Km 4.2 mM for lysine. Ornithine competitively inhibited the enzyme with a Ki of 0.8 mM. During cultivation of the pseudomonad the highest enzyme activity corresponds with the highest production rate of phaseolotoxin. At low toxin production, mutants exhibit a low enzyme activity and vice versa. Only those strains of different pathovarieties which are able to produce phaseolotoxin contain the enzyme. At 30 °C cultivation temperature, the enzyme activity was 50% of that at 18 °C, and toxin production decreased with increasing temperature. When microbes were grown on ribose, their enzyme activity was 60% lower than grown on glucose or glycerol. Toxin production was decreased to about 10% when growing on ribose. Amidinotransferase is considered to be one of the key enzymes of phaseolotoxin biosynthesis.
The effect of non‐ionic surfactants on the SOS‐inducing potency of 4‐nitroquinoline‐1‐oxide in Escherichia coli PQ37
Authors: Raabe Ferdinand , Janz Siegfried , Wolff Gerhard 
Published: February 2007

AbstractVarious non‐ionic surfactants affect the SOS‐inducing potency (SOSIP)1 of the model genotoxin, 4‐nitroquinoline‐1‐oxide, in Escherichia coli PQ37 to varying degrees, as measured by an automated version of the SOS chromotest. While there is little effect on the SOSIP value and other test parameters from Tween 20 and 80 and, with some reservation, Triton X305 and Tyloxapol, over the critical micelle concentration range, the SOSIP value increases in the presence of comparable concentrations of Triton X15, 45 and 100. A possible dependence of the tester strain's β‐galactosidase production and its growth inhibition on the HLB of the non‐ionic surfactants added is discussed.
Purification and properties of a malolactic enzyme from Leuconostoc oenos ATCC 23278
Authors: Naouri Pascal , Chagnaud Patrice , Arnaud Alain , Galzy Pierre 
Published: February 2007

AbstractThe malolactic enzyme of Leuconostoc ocnos ATCC 23278 was purified 136fold. The molecular weight was estimated at 132,000 when determined by gel filtration. The enzyme contained two identical subunits (Mw = 66,000 using sodium dodecyl sulfate gel electrophoresis). The malolactic enzyme catalyzes the NAD+‐ and Mn+‐dependent reaction L‐malate → L‐lactate + CO2. The apparent Km values for malic acid, NAD+, and Mn2+ were 17 mM, 0.044 mM, and 0.017 mM, respectively. The optimal pH and the optimal temperature for activity were 5.0, and 37 °C, respectively and the isoelectric point was pH 4.30. L‐lactate and ethanol were non‐competitive inhibitors, whereas succinate, citrate, and D‐tartrate showed competitive type inhibitions.
Immunochemical and structural analysis of the cell wall mannan as the basis of the taxonomic reidentification of a yeast strain
Authors: Pavliak Viliam , Kogan Grigorij , Sláviková Elena , Andula Jozef Š , Masler Ladislav 
Published: February 2007

AbstractThe immunochemical properties and structural features of D‐mannans from two Candida parapsilosis strains were studied. Weak cross‐reactivity of D‐mannans with antisera produced to C. parapsilosis strains was observed, as well as significant differences in the mannans structures were found by means of methylation analysis, acetolysis and 1H‐NMR spectroscopy. In view of the discrepancies found, new taxonomic identification of one strain was carried out. On the basis of assimilation of potassium nitrate and formation of hat‐shaped spores as well as other differences found by investigation of physiological characteristics, one strain of C. parapsilosis was reidentified as Hansenula anomala. This work demonstrates that immunochemical and structural investigations of cell‐wall polysaccharide components can serve as a basis for taxonomic identification of yeast strains.
Effect of organic soil amendments on the incidence of stalk rot of maize caused by Macrophomina phaseolina and Fusarium moniliforme
Authors: Osunlaja S. O. 
Published: February 2007

AbstractFive organic materials, Calopogonium sp., rice straw, wood sawdust, fresh guinea grass and poultry manure, were added to soil in a field with a recent history of high stalk rot in maize caused by Macrophomina phaseolina and Fusarium moniliforme. The two stalk rot organisms reacted differently to the organic amendments. All the amendments significantly reduced the incidence of Fusarium stalk rot disease. Amendment of soil with fresh Calopogonium leaves had almost no effect in controlling the incidence of Macrophomina phaseolina. Organic amendment with poultry manure stimulated the disease. The other amendments appeared to be equally effective in checking the disease. Suppression of the disease appeared to be related in increased microbial activities.
Cellular role of DNA polymerase I
Authors: Savic Dragutin J. , Jankovic Mila , Kostic Tatjana 
Published: February 2007

AbstractEscherichia coli possesses three well‐established DNA polymerases, I, II and III. DNA polymerase I (Pol 1) is the main repair polymerase in E. coli and also has a minor but important role in chromosomal replication. A major advantage of Pol I as an experimental system is its simplicity: unlike other replication enzymes, it is active as a single subunit. To a large extent, mutagenesis appears to be the result of (dis) functions of the DNA replication machinery. It is the purpose of this review to provide an integrated view of this relationship with particular emphasis on the role of Pol I in mutagenic events.
The Rice Yellow Mottle Virus situation in West Africa
Authors: Awoderu V. A. 
Published: February 2007

AbstractThe incidence and severity of the Rice Yellow Mottle Virus (RYMV) was monitored in various rice environments in West Africa. Its presence or absence being determinded through symptomatology and serological tests. RYMV was found in all the rice growing environments at different levels of incidence and severity which appear to be dependent on the type of variety planted, the rice environment and the climatic factors under which the rice is cropped. RYMV has been shown to cause losses ranging from 19.5% to 95.5%. Graminaceous weeds including some wild rices have been confirmed as alternate hosts for RYMV. Twenty five rice cultivars consisting of local and locally developed cultivars showed tolerant reactions to RYMV. Most of these varieties showed stable resistance to rice blast in an earlier study. The manifestation of RYMV symptoms on the uninoculated test rice varieties indicated the possibility of the virus being transmitted either through the virus vector or might be seedborne.
A solid‐phase enzyme immunoassay for the detection of tetanus toxin using human and murine monoclonal antibodies
Authors: Kiessig Stephan T. , Hentschel Christian , Jahn Sigbert , Mehl Michael , Starke Roland , Porstmann Thomas 
Published: February 2007

AbstractThree human and three murine monoclonal antibodies were tested for their reactivity to tetanus toxin and toxoid and used to establish an enzyme immunoassay specific for tetanus toxin. The dissociation constants of the monoclonal antibodies were between 3.91 × 10−9 and 8.48 × 10−12. Two human monoclonal antibodies recognized conformation determinants on the toxin, whereas the others reacted to the heavy chain. Only a combination of antibodies of the two species allowed the development of an enzyme immunoassay for the detection of tetanus toxin with a lower detection limit of 1.2 μg/l.
Use of α‐aminoadipate and lysine as sole nitrogen source by Schizosacharomyces pombe and selected pathogenic fungi
Authors: Ye Zhi‐Hai , Garrad Richard C. , Winston Melissa K. , Bhattacharjee J. K. 
Published: February 2007

Abstractα‐Aminodipate, an intermediate of the lysine biosynthetic pathway of fungi, or lysine when used as the sole nitrogen source in the medium was growth inhibitory and toxic to Saccharomyces cerevisiae. The fission yeast Schizosaccharomyces pombe and pathogenic fungi Candida albicans, Filobasidiella neoformans and Aspergillus fumigatus grew in the medium containing α‐aminoadipate as the sole nitrogen source. C. albicans, A. fumigatus, and one of the strains of F. neoformans also grew in the medium containing lysine as the sole nitrogen source. When grown in the α‐aminoadipate medium, only S. pombe accumulated a significant amount of α‐ketoadipate in the culture supernatant. Also, 14C‐α‐aminoadipate was converted to 14C‐α‐ketoadipate in vivo. In the ammonium sulfate medium, S. pombe cells converted 14C‐α‐aminoadipate to lysine. The levels of glutamate‐α‐ketoadipate transaminase, an enzyme responsible for the conversion of α‐aminoadipate to α‐ketoadipate, and α‐aminoadipate reductase, an enzyme required for the conversion of α‐aminoadipate to lysine, were similar in S. pombe cells grown in the α‐aminoadipate or ammonium sulfate medium. However, the level of homoisocitrate dehydrogenase, an enzyme before the α‐ketoadipate step, was twelvefold lower in S. pombe cells grown in the α‐aminoadipate medium compared to the level in cells grown in the ammonium sulfate medium. Pathogenic fungi used in this study did not accumulate α‐ketoadipate and α‐aminoadipate‐δ‐semialdehyde when grown in medium containing α‐aminoadipate and lysine, respectively, as sole nitrogen source. However, only pathogenic fungi used both lysine and α‐aminoadipate as sole nitrogen source. This unique metabolic property could be useful for the identification of these pathogens.
Optimization of nutrient medium for biosynthesis of gibberellic acid
Authors: Brückner B. , Blechschmidt D. , Recknagel R.‐D. 
Published: February 2007

AbstractA new method of optimization of the medium composition by biostatistical methods is reported. The well‐known Box‐Wilson scheme combined with the method of optimum curves was applied for an exploration of the response surface. The primary goal has been to optimize the concentration of nutrients for the production of gibberellic acid by the fungusGibberella fujikuroiwith a minimum number of experiments. As the result, a nearly fivefold improvement yield of the was achieved performing only two experiments.
Purification and characterization of the tyrosinase of Streptomyces michiganensis DSM 40015
Authors: Philipp Stephan , Held Thomas , Kutzner Hans J. 
Published: February 2007

AbstractTyrosinase of Streptomyces michiganensis DSM 40015 was purified 61‐fold from the culture broth: After a fractionated ammonium sulfate precipitation the enzyme was separated by hydrophobic interaction chromatography with Phenyl‐Sepharose and ionic interaction chromatography with CM‐Cellulose; finally a gel filtration with Sephadex G‐75 yielded 1.7% of the originally existent enzyme. SDS gel‐electrophoresis of the purified enzyme showed two bands representing a size of 34500 and 32000 dalton, respectively. However, by isoelectric focussing only one band could be found exhibiting an isoelectric point of approximately 9.0. Temperature and pH‐optimum of the enzyme activity were 33°C and pH 7.0, respectively. Whereas the enzyme is specific in regard to the aromatic part of its substrate variations of the aliphatic rest are tolerated.
Purification and properties of the β‐glucosidase of a new strain of Candida molischiana able to work at low pH values: Possible use in the liberation of bound terpenols
Authors: Vasserot Yann , Chemardin Patrick , Arnaud Alain , Galzy Pierre 
Published: February 2007

AbstractA yeast strain isolated in the laboratory was studied and classified as a Candida molischiana. The β‐glucosidase of this yeast strain was then purified. Its molecular weight, estimated by gel filtration, was 100,000. The enzyme consisted of only one subunit, identified after treatment with sodium dodecyl sulfate. Maximum activity was obtained at 55°C and pH 4 but the enzyme still possessed activity at pH 2.5. Active against different glucosides with β(1–2), β(1–3), β(1–4), β(1–6), and α(1–4) configurations it presented an α(1–6)‐arabinofuranosidase activity. The enzyme was competitively inhibited by glucose (Ki 9.5 mm). A glucosyltransferase activity appeared in the presence of ethanol. The enzyme was constitutive but its synthesis was repressed by glucose.
Purification and characterization of an inducible L‐lysine: 2‐oxoglutarate 6‐aminotransferase from Candida utilis
Authors: Hammer Thomas , Bode Rüdiger 
Published: February 2007

AbstractL‐Lysine: 2‐oxoglutarate 6‐aminotransferase (EC 2.1.6.36) was purified 202‐fold from the yeast Candida utilis. The subunit Mr estimated by sodium dodecyl sulfate polyacrylamide gel electrophoresis was 40 kDa. The Mr of the native enzyme was estimated to be 83 kDa by gel filtration, suggesting a dimeric structure. The enzyme exhibits absorption maxima at 280, 340 and 420 nm, and binds 2 mol pyridoxal‐5‐phosphate/mol of the native enzyme. The aminotransferase has a maximum activity at pH 8.5 and at 4 °C. 2‐Oxoglutarate is the best amino acceptor with L‐lysine as amino donor. Lower activity is observed with oxaloacetate (38%), pyruvate (19%) and 2‐oxoadipate (7%) as acceptor or with L‐thialysine (13%) as donor. The Km values are 2.5 mM for L‐lysine, 3.8 mM for 2‐oxoglutarate and 0.015 mM for pyridoxal‐5‐phosphate. The enzyme activity is induced in cells grown in the presence of L‐lysine.
Studies on the root nodules of leguminous trees V. Production of indole acetic acid by a Bradyrhizobium sp. from the root nodules of a leguminous tree, Acacia auriculiformis A. CUNN
Authors: Bhattacharyya R. N. , Basu P. S. 
Published: February 2007

AbstractThe Bradyrhizobium sp., isolated from the root nodules of Acacia auriculiformis A. CUNN., a member of Mimosaceae, produced 17.0 μg/ml of indole acetic acid (IAA) from tryptophan in culture. The bacteria preferred D‐isomer over DL‐ or L‐isomer of tryptophan for IAA production. The IAA production could be promoted in culture medium up to 4.350% over control by supplementing the medium with fructose (0.5%), MnSO4 (0.1 μg/ml), glutamine (0.1%) and sodium dodecyl sulfate (SDS, 1.0 μg/ml). The possible relationship between the rhizobial IAA production and legume‐rhizobia symbiosis is discussed. The root nodules of leguminous plants are the result of rhizobial infection and are highly specialized structure which provide a special environment for the biological reduction of dinitrogen by the microsymbiont. Formerly nitrogen fixation was thought to be the only function of the nodules. Later hormone production by Rhizobium spp. drew great attention due to its involvement in the formation and growth of the nodules (KEFFORD et al. 1960, NUTMAN 1977). Rhizobium spp. are known to produce IAA from tryptophan in culture (DULLAART 1970, BHATTACHARYYA and BASU 1991). But most of the information is restricted to Rhizobium spp. isolated from the root nodules of the herbs of Fabaceae. This may be due to the immense economic importance of the pulses. Probably the first report on rhizobial IAA production of a tree legume was from Pongamia pinnata (SINHA and BASU 1981). Moreover, most of the leguminous plants so far studied belong to the family Fabaceae or Caesalpiniaceae. The report on rhizobial IAA production in a tree of the family Mimosaceae is very much scanty. Acacia auriculiformis is a leguminous tree of the neglected and unexplored family Mimosaceae. The mature nodule of A. auriculiformis contained 5.0 μg/g IAA (BHATTACHARYYA and BASU 1986/87), but any information on the ability of IAA production by its microsymbionts is lacking. But such information may throw some new light on the better understanding of the symbiosis of the root nodules. In addition, this neglected tree is also an useful sand binder and the seeds of this plant contain an important fatty acid (AMBASTA 1986). The purpose of this study was to throw some light on the IAA‐synthesizing capacity of the Bradyrhizobium sp. and to direct an effort to optimize the cultural requirement of the incubation medium for maximum IAA production by different supplements. This investigation yielded some interesting and tempting results which would be helpful to have an insight on the legume‐rhizobial symbiosis.
Flavonoids in seed coats ofMedicago arboreaandM. strasseri(Leguminosae): Ecophysiological aspects
Authors: Perez‐Garcia Felix , Ceresuela Jose L. , Gonzalez Aldo E. , Aguinagalde Itziar 
Published: February 2007

AbstractMedicago arborea and M. strasseriare two leguminous species of great rusticity, valuables as ornamental and fodder plants. The high susceptibility to the fungal attack of their seeds limited those potential uses. Seven main flavonoids (Luteolin; Luteolin‐7‐glucoside; 7,3′,4′‐Trihydroxyflavone; 7,3′,4′‐Trihydroxyflavone 7‐glucoside; 7,4′‐Dihydroxyflavone; Quercetin‐3‐glucoside; Kaempferol‐3‐glucoside) were identified in the seed coats of both species. Their ecophysiological role is studied by bioassays: inhibition test of germination and radicle growth ofLactuca sativaand inhibition test of growth ofAlternaria alternataandPleospora herbarumfungus isolated from the seed coats.