| novel rosette formation of murine spleen cells with autologous red blood cells. | spleen cells of normal balb/c mice formed rosettes with autologous red blood cells, and the formation was calcium ion dependent. peritoneal exudate cells, bone marrow cells and thymocytes did not form such rosettes. spleen cells were passed over a sephadex g-10 column or incubated on a plastic surface in order to eliminate adherent cells from them. cells obtained by both these methods were unable to form rosettes. b cell-, t cell- and natural killer cell-enriched fractions in spleen cells were u ... | 2000 | 10839565 |
| solid-state fermentation with aspergillus niger for cellobiase production. | aspergillus niger nrrl3 was cultivated in a moist wheat bran and ground corncob solid medium supplemented with inorganic minerals for the production of cellobiase (beta-1,4-glucosidase, ec 3.2.1.21). with this method, a. niger nrrl3 was able to produce a high concentration of cellobiase (215 iu/g of solid substrate) after 96 h of incubation. temperature and moisture content affected final cellobiase titers. the best conditions for cellobiase production from solid substrate by a. niger nrrl3 were ... | 2000 | 10849832 |
| adsorption of inulinases in ion-exchange columns. | the use of adsorption columns packed with ion-exchange resins for recovering, concentrating and purifying proteins is now widespread. the present work consists of a study on the dynamic behavior of adsorption columns that uses two kinds of adsorbents: a cationic and an anionic resin. a frontal analysis of the columns was performed with experimental data obtained from fructozyme, a mixture of inulinase enzymes. the parameters of a langmuir type of isotherm and adsorption kinetics were obtained fr ... | 2000 | 10849858 |
| penicillopepsin-jt2, a recombinant enzyme from penicillium janthinellum and the contribution of a hydrogen bond in subsite s3 to k(cat). | the nucleotide sequence of the gene (pepa) of a zymogen of an aspartic proteinase from penicillium janthinellum with a 71% identity in the deduced amino acid sequence to penicillopepsin (which we propose to call penicillopepsin-jt1) has been determined. the gene consists of 60 codons for a putative leader sequence of 20 amino acid residues, a sequence of about 150 nucleotides that probably codes for an activation peptide and a sequence with two introns that codes for the active aspartic proteina ... | 2000 | 10850809 |
| regulation of expression of the aspergillus niger benzoate para-hydroxylase cytochrome p450 system. | cytochrome p450 enzyme systems are found throughout nature and are involved in many different, often complex, bioconversions. in the endoplasmic reticulum of the filamentous fungus aspergillus niger a cytochrome p450 enzyme system is present that is capable of the para-hydroxylation of benzoate. the expression of the two genes encoding the components of this system, the cytochrome p450 gene encoding benzoate para-hydroxylase (bpha) and the gene encoding cytochrome p450 reductase (cpra), is induc ... | 2000 | 10852481 |
| identification of a glutamic acid and an aspartic acid residue essential for catalytic activity of aspergillopepsin ii, a non-pepsin type acid proteinase. | aspergillopepsin ii from aspergillus niger var. macrosporus is a non-pepsin type or pepstatin-insensitive acid proteinase. to identify the catalytic residues of the enzyme, all acidic residues that are conserved in the homologous proteinases of family a4 were replaced with asn, gln, or ala using site-directed mutagenesis. the wild-type and mutant pro-enzymes were heterologously expressed in escherichia coli and refolded in vitro. the wild-type pro-enzyme was shown to be processed into a two-chai ... | 2000 | 10854444 |
| antimicrobial effects of finnish plant extracts containing flavonoids and other phenolic compounds. | plant phenolics, especially dietary flavonoids, are currently of growing interest owing to their supposed functional properties in promoting human health. antimicrobial screening of 13 phenolic substances and 29 extracts prepared from finnish plant materials against selected microbes was conducted in this study. the tests were carried out using diffusion methods with four to nine microbial species (aspergillus niger, bacillus subtilis, candida albicans, escherichia coli, micrococcus luteus, pseu ... | 2000 | 10857921 |
| reassessment of the active site quino-cofactor proposed to occur in the aspergillus niger amine oxidase ao-i from the properties of model compounds. | quino-cofactors have been found in a wide variety of prokaryotic and eukaryotic organisms. two variants have, thus far, been demonstrated to derive from tyrosine precursors: these are the 2,4, 5-trihydroxyphenylalanine quinone (topa quinone or tpq) [janes, s. m. , et al. (1990) science 248, 98] and an o-quinone analogue containing the side chain of a lysine residue (lysyltyrosine quinone or ltq) [wang, s. z., et al. (1996) science 273, 1078]. additionally, a third variant of the family of tyrosi ... | 2000 | 10858309 |
| comparative in vitro antifungal activity of amphotericin b lipid complex, amphotericin b and fluconazole. | amphotericin b (amb) is considered the gold standard in the treatment of serious systemic mycoses in spite of its nephrotoxicity and adverse effects. association with lipids enables larger doses of amb to be given with a longer t((1/2)) and c(max), without the toxic effects at lower concentrations. liposome-encapsulated amb shows a lower affinity for mammalian cells and improves v(d), thus decreasing toxicity. amphotericin b lipid complex (ablc) is an amb formulation associated with a biodegrada ... | 2000 | 10859429 |
| characterization of two novel defense peptides from pea (pisum sativum) seeds. | a fraction that possesses antifungal activity against aspergillus niger has been isolated from seeds of the pea (pisum sativum) by ammonium sulfate fractionation followed by gel filtration on sephadex g-75. on further purification by reverse-phase high performance liquid chromatography, two small cysteine-rich polypeptides were obtained (psd1 and psd2). they are localized primarily in vascular bundles and epidermis tissues of pea pods and exhibit high antifungal activity toward several fungi, di ... | 2000 | 10860545 |
| antimicrobial activity of essential oils and ethanol extract of phlomis fruticosa l. (lamiaceae). | the essential oils and an ethanol extract of phlomis fruticosa l. were evaluated for antibacterial and antifungal activities. seven bacterial and seven fungal species were used. among them were human, animal and plant pathogens, food poisoning bacteria and fungi which are known as potential mycotoxin producers. the essential oils showed antibacterial activity against staphylococcus aureus, escherichia coli, bacillus subtilis, klebsiella pneumoniae and micrococcus luteus. the essential oils extra ... | 2000 | 10861970 |
| exploiting unusual affinity of usual polysaccharides for separation of enzymes on fluidized beds. | two polysaccharides, alginate and chitosan, showed unusual affinity and bound alpha-amylase (from various sources) and aspergillus niger cellulase, respectively. the beads prepared from these polymers were successfully used for the purification of the respective enzymes by fluidized bed affinity chromatography. alpha-amylase from wheat germ could be purified by 58-fold with about 90% recovery of activity. aspergillus niger cellulase, on the other hand, was purified by 30-fold with 80% recovery o ... | 2000 | 10862902 |
| influence of fowl uropygial gland and its secretory lipid components on the growth of skin surface fungi of fowl. | fungal species, which were shown to colonize consistently on the skin surface of the breast region of adult (1 year old) white leghorn fowl, were identified as aspergillus sydowii, a. tamarii, a. rugulosus and absidia corymbifera. of these, a. sydowii and a. tamarii were the dominant forms. two species of fungi, namely, aspergillus niger and scopulariopsis brevicaulis were shown to be present in the cultures of the scrubbings from breast skin surface after 60 days of captivity of the fowls. exti ... | 1999 | 10865889 |
| antifungal substances against pathogenic fungi, talaroconvolutins, from talaromyces convolutus. | the dichloromethane extract of talaromyces convolutus cultivated on barley exhibited antifungal activity against candida albicans. in the course of a search for the active compounds, four new tetramic acid derivatives, talaroconvolutins a (1), b (2), c (3), and d (4), were isolated along with zg-1494alpha (5), and mitorubrin derivatives. the structures of talaroconvolutins a-d (1-4) were established on the basis of spectroscopic and chemical investigations and chemical correlations. the antifung ... | 2000 | 10869198 |
| onychomycosis in malaysia. | the common etiological agents of onychomycosis are dermatophytes, molds and yeasts. a mycological nail investigation of onychomycosis using direct microscopy and culture was conducted by the mycology unit, department of medical microbiology, university of malaya from march 1996 to november 1998. the study involved 878 nail clippings or subungal scrapings from subjects with onychomycosis. on direct microscopy examination, 50% of the specimens were negative for fungal elements. on culture, 373 spe ... | 1999 | 10872513 |
| fungal endophthalmitis after a single intravenous administration of presumably contaminated dextrose infusion fluid. | to report fungal endophthalmitis in nonimmunocompromised patients, each of whom received a single intravenous administration of presumably contaminated dextrose infusion fluid for minor ailments in rural settings. | 2000 | 10872931 |
| studies on the production of fungal peroxidases in aspergillus niger. | to get insight into the limiting factors existing for the efficient production of fungal peroxidase in filamentous fungi, the expression of the phanerochaete chrysosporium lignin peroxidase h8 (lipa) and manganese peroxidase (mnp) h4 (mnp1) genes in aspergillus niger has been studied. for this purpose, a protease-deficient a. niger strain and different expression cassettes have been used. northern blotting experiments indicated high steady-state mrna levels for the recombinant genes. manganese p ... | 2000 | 10877800 |
| characterization of acid-stable glucose isomerase from streptomyces sp., and development of single-step processes for high-fructose corn sweetener (hfcs) production. | the glucose isomerase from streptomyces olivaceoviridis e-86 was purified by chromatographic procedures, showing one single protein band in the sds-page. the enzyme had high acid stability, and there was no loss in enzyme activity at ph 5.0 after incubation at 60 degrees c for 30 hr. the enzyme had sufficients activity at 60 degrees c, ph 5.5, (which is the reaction condition for a single-step process with a glucoamylase from a. niger), and at 58 degrees c, ph 6.0, (condition with a glucoamylase ... | 2000 | 10879462 |
| ph-dependence of the fast step of maltose hydrolysis catalysed by glucoamylase g1 from aspergillus niger. | the presteady-state kinetic parameters of the interaction ofwild-type glucoamylase from aspergillus niger (ec 3.2.1.3)with maltose were obtained and analysed in the ph range 3-7 withintervals of 0.25 ph units. in all cases the following three-step reaction scheme was found to apply. [equation: see text]. the general result of the analysis of the presteady-state kinetics is that glucoamylase g1 is affected by the protonation states of three groups, with pk(a) values of 2.7, 4.5 and 5.7 in the fre ... | 2000 | 10880362 |
| a new affinity ligand for the isolation of a single 'feruloyl esterase' (fae-iii) from aspergillus niger. | 8-aminooctyl 5'-s-coniferyl-5'-deoxy-thio-alpha-l-arabinofuranoside has been synthesised and shown to be a selective affinity ligand for the feruloyl esterase iii of aspergillus niger. the hydrolyses of methyl 5-o-coumaroyl, feruloyl, or sinapoyl alpha-l-arabinofuranosides by this enzyme proceed at comparable rates. | 2000 | 10882004 |
| hplc analysis and optimization of enzymatic synthesis of 4'-o-(beta-d-glucopyranosyl)-d-pantothenic acid. | we analyzed beta-glucosidase-catalyzed transglucosylation to d-pantothenic acid using a reversed-phase hplc system in order to obtain 4'-o-(beta-d-glucopyranosyl)-d-pantothenic acid (pag) at a higher yield. the hplc system was simpler and more straight-forward for the pag analysis than the previously employed bioassay method and could also be adopted for efficient isolation of pag. penicillium decumbens naringinase showed the highest glucosyl transfer activity to d-pantothenic acid, and the reac ... | 2000 | 10885798 |
| endoxylanases in durum wheat semolina processing: solubilization of arabinoxylans, action of endogenous inhibitors, and effects on rheological properties. | endoxylanases seriously affect the rheological properties of durum wheat (triticum durum desf.) semolina spaghetti doughs prepared with, and as evaluated, by the farinograph. under the experimental conditions, control doughs (34.9% moisture content) made from two semolinas (sema and semb) yielded a maximal consistency of 525 and 517 farinograph units (fu), with, respectively, 19.4 and 16.4% of the total level of arabinoxylans (tot-ax) being water-extractable (we-ax). when 75.4 somogyi units/50 g ... | 2000 | 10888491 |
| enzymatic formation of ether linkage producing shoyuflavones from genistein and (+/-)-trans-epoxysuccinic acid. | the production mechanism of shoyuflavones, conjugated ethers of isoflavones with tartaric acid and isolated from fermented soy sauce, was studied. in the high molecular weight fraction of the culture extract of aspergillus oryzae, genistein was transformed into shoyuflavone b in the presence of (+/-)-trans-epoxysuccinic acid but not in the low molecular one. asp. sojae and asp. tamarii showed high activity similar to asp. oryzae but none of asp. niger, rhizopus oligosporus, and mucor praini did. ... | 2000 | 10888513 |
| induction of the soybean phytoalexins coumestrol and glyceollin by aspergillus. | several isoflavonoid phytoalexins produced by soybeans are known to be estrogenic, with potential beneficial health effects in humans. increased production of phytoalexins by the soybean plant will facilitate research efforts in this area. in this study, phytoalexin induction and accumulation in soybean cotyledon tissue was observed using four species of aspergillus: a. sojae, a. oryzae, a. niger, and a. flavus. all four aspergillus species tested elicited phytoalexin accumulation in living soyb ... | 2000 | 10888516 |
| subsite mapping of aspergillus niger endopolygalacturonase ii by site-directed mutagenesis. | to assess the subsites involved in substrate binding in aspergillus niger endopolygalacturonase ii, residues located in the potential substrate binding cleft stretching along the enzyme from the n to the c terminus were subjected to site-directed mutagenesis. mutant enzymes were characterized with respect to their kinetic parameters using polygalacturonate as a substrate and with respect to their mode of action using oligogalacturonates of defined length (n = 3-6). in addition, the effect of the ... | 2000 | 10893426 |
| cellular localization and metabolic function of n-butylamine-induced amine oxidases in the fungus aspergillus niger aku 3302. | using transmission electron microscopy, the amine oxidase activity in aspergillus niger aku 3302 was localized to the outer side of the cell wall but not inside the cell using the cerium perhydroxide deposition method. the presence of cerium in the deposit was confirmed by energy-dispersive microanalysis of x-rays. interestingly, immunocytochemical localization using gold labeling with a specific antibody indicated the presence of amine oxidase protein inside the cell wall and not only on the ou ... | 2000 | 10896215 |
| regiospecific transglycolytic synthesis and structural characterization of 6-o-alpha-glucopyranosyl-glucopyranose (isomaltose). | the enzymatic synthesis of 6-o-alpha-glucopyranosyl-glucopyranose (isomaltose) was achieved. the regiospecific transglycosylation reaction was catalyzed by a crude preparation of alpha-d-glucosidase from aspergillus niger, using p-nitrophenyl alpha-d-glucopyranose as the donor and glucopyranose as the acceptor. the yield of the reaction was 59% on a molar basis with respect to the donor. the structural identity of the product was fully determined by hplc, hpaec-pad, ionspray mass spectrometry an ... | 2000 | 10903902 |
| purification and biochemical characterization of a novel thermostable lipase from aspergillus niger. | an extracellular 1,3-specific lipase with molecular weight of 35.5 kda and an isoelectric point of 4.4 from aspergillus niger has been purified 50-fold by ph precipitation followed by a series of chromatographic steps with an overall yield of 10%. the enzyme was homogeneous as judged by denaturing polyacrylamide gel electrophoresis and size-exclusion fast-performance liquid chromatography. it contained 2.8% sugar which was completely removed by endoglycosidase f treatment, and the deglycosylated ... | 2000 | 10907784 |
| enzyme, bacterial inoculant, and formic acid effects on silage composition of orchardgrass and alfalfa. | we evaluated the effects of cellulase (from trichoderma longibrachiatum) application rates on neutral detergent fiber (ndf) concentration and fermentation products of orchardgrass (dactylis glomerata l.) and alfalfa (medicago sativa l.) silages harvested with decreasing dry matter (dm) digestibility. additionally, the impacts of inoculant (lactobacillus plantarum and pediococcus cerevisiae), pectinase (from aspergillus niger), or formic acid on silage composition were studied. forages wilted to ... | 2000 | 10908057 |
| a discussion of anti-aspergillus niger glucose oxidase monoclonal antibody reactivity to red blood cells of several species. | we observed that mouse spleen cells from rosettes with autologous red blood cells (rbcs) and that rosette-formation was suppressed by anti-aspergillus niger glucose oxidase monoclonal antibody (mab). in the present study, we investigated whether rbcs of species besides mice have the structure recognized by anti-a. niger glucose oxidase mab by using rosette-formation and complement-mediated hemolysis. lysates of monkey and human rbcs did not suppress rosette-formation whereas autologous (mouse), ... | 2000 | 10911721 |
| energetic and mechanistic studies of glucoamylase using molecular recognition of maltose oh groups coupled with site-directed mutagenesis. | molecular recognition using a series of deoxygenated maltose analogues was used to determine the substrate transition-state binding energy profiles of 10 single-residue mutants at the active site of glucoamylase from aspergillus niger. the individual contribution of each substrate hydroxyl group to transition-state stabilization with the wild type and each mutant ga was determined from the relation delta(deltag()) = -rt ln[(k(cat)/k(m))(x)/(k(cat)/k(m))(y)], where x represents either a mutant en ... | 2000 | 10913265 |
| significance of aspergillemia in patients with cancer: a 10-year study. | the significance of blood cultures positive for aspergillus species for patients with cancer remains unclear. the significance of aspergillemia in 36 cancer patients over a 10-year period was evaluated. true aspergillemia was rare, occurred late in the course of aspergillosis, and was seen exclusively in patients with hematologic malignancies. | 2000 | 10913421 |
| ultrasonication of pyrogenic microorganisms improves the detection of pyrogens in the mono mac 6 assay. | the monocytic cell line mono mac 6 is sensitive to pyrogens. when exposed to pyrogens secretion of interleukin-6 is induced. however, some eukaryotic pyrogenic microorganisms are not detectable. the aim of this study is to introduce a pretreatment of samples to expand the detection range of the assay. the interleukin-6 inducing capacity of a broad spectrum of uv-killed and ultrasonicated microorganisms is examined in mono mac 6 cells. the interleukin-6 secretion is determined in a sandwich immun ... | 2000 | 10913753 |
| synthesis and antifungal activities of 5/6-arylamino-4,7-dioxobenzothiazoles. | 5/6-arylamino-4,7-dioxobenzothiazoles were synthesized and tested for in vitro antifungal activities against pathogenic fungi. most of the tested 4,7-dioxobenzothiazoles exhibited potent antifungal activities against candida species and aspergillus niger. | 2000 | 10915058 |
| prevalence and outcome of invasive fungal infections in 1,963 thoracic organ transplant recipients: a multicenter retrospective study. italian study group of fungal infections in thoracic organ transplant recipients. | fungal infections (fi) after solid organ transplantation (tx) remain a major cause of morbidity and mortality. aspergillus and candida account for more than 80% of fi. | 2000 | 10919584 |
| evaluation of the antimicrobial property of the stem bark of picralima nitida (apocynaceae). | the basic fraction (bf) of the methanol extract of the stem bark of picralima nitida (family apocynaceae) exhibited significant antimicrobial activity against a wide range of gram-positive bacteria and fungi, but limited activity against gram-negative bacteria. the bf had a similar minimum inhibitory concentration (mic) for s. aureus to the control drug ampicillin, and lower mic values against a. flavus and a. niger than those of tiaconazole. values of the minimum bactericidal concentration (mbc ... | 2000 | 10925406 |
| direct quantification of aspergillus niger spore adhesion in liquid using an atomic force microscope. | an atomic force microscope has been used to quantify directly the adhesion between single aspergillus niger spores and freshly cleaved mica surfaces. the measurements used "spore probes" constructed by immobilizing a single spore at the apex of a tipless afm cantilever. adhesion was quantified from force-distance data for the retraction of the spore from the surface. studies in nacl solutions over a range of ph and electrolyte concentration showed that the decrease of long-range electrostatic re ... | 2000 | 10926484 |
| isolation of fungi from rose bush thorns. | rose bush thorns from plants in the oklahoma city area were cultured to determine the prevalence and species of fungi present. one hundred fifty isolates grew from thorns on 103 plants. all thorns harbored at least one species, while one thorn had five species of fungi. of the 21 fungal species isolated, all are known human pathogens, although most rarely cause disease in immunocompetent individuals. alternarium sp., bipolaris sp., aspergillus niger, curvularia sp., and fusarium sp. were the mos ... | 2000 | 10927884 |
| c-jun and rack1 homologues regulate a control point for sexual development in aspergillus nidulans. | amino acid limitation results in impaired sexual fruit body formation in filamentous fungi such as aspergillus nidulans. the starvation signal is perceived by the cross-pathway regulatory network controlling the biosynthesis of translational precursors and results in increased expression of a transcriptional activator encoded by a c-jun homologue. in the presence of amino acids, the gene product of the mammalian rack1 homologue cpcb is required to repress the network. growth under amino acid sta ... | 2000 | 10931303 |
| optimization of the catalytic properties of aspergillus fumigatus phytase based on the three-dimensional structure. | previously, we determined the dna and amino acid sequences as well as biochemical and biophysical properties of a series of fungal phytases. the amino acid sequences displayed 49-68% identity between species, and the catalytic properties differed widely in terms of specific activity, substrate specificity, and ph optima. with the ultimate goal to combine the most favorable properties of all phytases in a single protein, we attempted, in the present investigation, to increase the specific activit ... | 2000 | 10933495 |
| a comparative study of the in vitro susceptibilities of clinical and laboratory-selected resistant isolates of aspergillus spp. to amphotericin b, itraconazole, voriconazole and posaconazole (sch 56592). | we investigated the in vitro susceptibilities of clinical and laboratory-selected aspergillus spp. to posaconazole, and compared the results with those obtained for amphotericin b, itraconazole and voriconazole. conidial suspensions from clinical isolates (284 aspergillus fumigatus, 66 aspergillus niger, 31 aspergillus flavus and 43 aspergillus spp.) and laboratory-selected resistant a. fumigatus isolates (15 resistant to amphotericin b, 25 to itraconazole and 12 to voriconazole) were prepared a ... | 2000 | 10933645 |
| quantification of intracellular metabolic fluxes from fractional enrichment and 13c-13c coupling constraints on the isotopomer distribution in labeled biomass components. | a method for the quantification of intracellular metabolic flux distributions from steady-state mass balance constraints and from the constraints posed by the measured 13c labeling state of biomass components is presented. two-dimensional nmr spectroscopy is used to analyze the labeling state of cell protein hydrolysate and cell wall components. no separation of the biomass hydrolysate is required to measure the degree of 13c-13c coupling and the fractional 13c enrichment in various carbon atom ... | 1999 | 10935929 |
| construction and characterization of an oxalic acid nonproducing strain of aspergillus niger. | aspergillus niger produces oxalic acid as a by-product which causes problems with downstream processing of industrial enzymes. to overcome this problem the oah gene encoding oxaloacetate hydrolase (ec 3.7.1.1) was disrupted in a glucoamylase-producing strain of a. niger and the resulting strain was incapable of producing oxalic acid. the strain with the disrupted gene was compared with the wild-type strain producing oxalic acid in batch cultivations. the specific growth rate of both strains was ... | 2000 | 10935933 |
| expression of glucose oxidase by using recombinant yeast. | the glucose oxidase gene (go) of aspergillus niger was cloned into the yeast shuttle vector yep352 with combinations of various promoters and terminators, and then used to transform saccharomyces cerevisiae. expressed go was successfully secreted into culture medium due to the presence of the intrinsic signal peptide of go. four different promoters fused to go were tested: bidirectional galactose dehydrogenase 1 and 10 (gal1, gal10) promoters, glyceraldehyde-3-phosphate dehydrogenase (gpd) promo ... | 2000 | 10936658 |
| purification and partial characterization of fructosyltransferase and invertase from aspergillus niger as0023. | fructosyltransferase (ec.2.4.1.9) and invertase (ec.3.2.1.26) have been purified from the crude extract of aspergillus niger as0023 by successive chromatographies on deae-sephadex a-25, sepharose 6b, sephacryl s-200, and concanavalin a-sepharose 4b columns. on acrylamide electrophoresis the two enzymes, in native and denatured forms, gave diffused glycoprotein bands with different electrophoretic mobility. on native-page and sds-page, both enzymes migrated as polydisperse aggregates yielding bro ... | 2000 | 10936662 |
| polygalacturonase is the key component in enzymatic retting of flax. | seven commercial enzyme mixtures were tested for their ability to perform retting of flax (i.e. to separate flax fibers by partly removal of middle lamella) and were assayed for hydrolysis of xylan, cellulose and four kinds of pectin. the only activity that showed correlation to the ability to perform retting was the degradation of low esterfied pectin. a purified aspergillus niger polygalacturonase was also shown to be able to perform retting. from this data it is hypothesized that degradation ... | 2000 | 10936663 |
| microbial transformation of dehydropinguisenol by aspergillus sp. | two metabolites were obtained by microbial transformation of a furanosesquiterpene alcohol, dehydropinguisenol, using aspergillus niger and aspergillus cellulosae. their structures were established as 10-oxo-lejeuneapinguisenol and lejeuneapinguisenol on the basis of their spectroscopic data. the latter compound was obtained after 4 and 9 days of incubation with a. cellulosae at 30 degrees c and 25 degrees c, respectively. aspergillus niger produced both metabolites after 3 and 5 days incubation ... | 2000 | 10939348 |
| metabolism of citric acid production by aspergillus niger: model definition, steady-state analysis and constrained optimization of citric acid production rate. | in an attempt to provide a rational basis for the optimization of citric acid production by a. niger, we developed a mathematical model of the metabolism of this filamentous fungus when in conditions of citric acid accumulation. the present model is based in a previous one, but extended with the inclusion of new metabolic processes and updated with currently available kinetic data. among the different alternatives to represent the system behavior we have chosen the s-system representation within ... | 2000 | 10940866 |
| study on heterogeneity of beta-glucosidase from aspergillus species by using counter-current distribution. | beta-glucosidase plays a key role in cellulose degradation by cleaving its cellobiose units to glucose. the heterogeneity of the enzyme has been studied earlier by isoelectric focusing and several isoforms were found in the culture filtrate of trichoderma and aspergillus species. an aqueous two-phase system is an alternative fractionation method in which proteins are separated according to their net charge and surface properties. a dextran 500-poly(ethylene glycol) 8000 system was used to study ... | 2000 | 10942293 |
| improved outcome of pulmonary aspergillosis in heart transplant recipients with early diagnosis and itraconazole treatment. | pulmonary aspergillosis is a severe complication in heart transplant recipients. the drug of choice for this infection is amphotericin b, but its use is limited because of its side effects. we observed six cases of pulmonary aspergillosis in a group of 200 patients who had received heart transplants from january 1988 to january 1999. predisposing factors such as previous rejection, neutropenia and/or cytomegalovirus reactivation were present in all patients. the clinical presentation was charact ... | 2000 | 10945197 |
| substrate selectivity in aspergillus niger ku-8 acid phosphatase ii using phosphoryl oligosaccharides. | the intracellular acid phosphatase ii (acpase ii) produced by aspergillus niger ku-8 preferentially dephosphorylates c-6 phosphate groups rather than c-3 phosphate groups of phosphoryl oligosaccharides. in this study, the kinetic parameters of acpase ii were measured. 3(2)-phosphoryl maltotriose and 6(2)-phosphoryl maltotriose, which differ only in the binding position of the phosphate group, were prepared and used as the substrates. the km for both substrates were similar. however, the k(cat) v ... | 2000 | 10945278 |
| analysis of different de-esterification mechanisms for pectin by enzymatic fingerprinting using endopectin lyase and endopolygalacturonase ii from a. niger. | a series of pectins with different distribution patterns of methyl ester groups was produced by treatment with either plant (p-pme) or fungal pectin methyl esterases (f-pme) and compared with those obtained by base catalysed de-esterification. the products generated by digestion of these pectins with either endopectin lyase (pl) or endopolygalacturonase ii (pg ii) from aspergillus niger were analysed using matrix assisted laser desorption ionisation mass spectrometry (maldims) and high-performan ... | 2000 | 10945678 |
| quantification of the amount of galacturonic acid residues in blocksequences in pectin homogalacturonan by enzymatic fingerprinting with exo- and endo-polygalacturonase ii from aspergillus niger. | a method to determine the amount of galacturonic acid in blocksequence (bs) in pectin homogalacturonan (hg) is described. the method is based on a combination of endopolygalacturonase ii (endo-pg ii) and exopolygalacturonase (exo-pg) digestion followed by quantification of the liberated galacturonic acid monomer. the amount of monomers released is directly related to the amount of non-esterified galacturonic acid units located between two other non-esterified galacturonic acids units on the hg c ... | 2000 | 10945680 |
| production of catalase and glucose oxidase by aspergillus niger using unconventional oxygenation of culture. | a novel method for increasing dissolved oxygen concentration in culture media has been developed. it involves adding hydrogen peroxide (h2o2) to the medium which is then decomposed to oxygen and water by catalase. some factors affecting oxygenation of culture were investigated. maximal oxygen concentration occurred in 50 ml of the medium containing 0-2 g wet mycelium and 0.2% glucose at ph 5.0. a new apparatus for automated addition of h2o2 to the bioreactor to keep the dissolved oxygen concentr ... | 2000 | 10945783 |
| degradation of ochratoxin a by aspergillus species. | mycotoxin contamination of agricultural products is a serious health hazard throughout the world. besides attempts to eliminate mycotoxins from contaminated substrates by physical and chemical methods, the ability of microbes to degrade mycotoxins is now being widely examined. in this study, several aspergillus species were examined for their ability to degrade ochratoxin a. a. fumigatus and black aspergillus strains were found to detoxify ochratoxin a in culture media. the kinetics of ochratoxi ... | 2000 | 10946833 |
| new type of starch-binding domain: the direct repeat motif in the c-terminal region of bacillus sp. no. 195 alpha-amylase contributes to starch binding and raw starch degrading. | the alpha-amylase from bacillus sp. no. 195 (baa) consists of two domains: one is the catalytic domain similar to alpha-amylases from animals and streptomyces in the n-terminal region; the other is the functionally unknown domain composed of an approx. 90-residue direct repeat in the c-terminal region. the gene coding for baa was expressed in streptomyces lividans tk24. three active forms of the gene products were found. the ph and thermal profiles of baas, and their catalytic activities for p-n ... | 2000 | 10947962 |
| production of citric acid using immobilized conidia of aspergillus niger. | conidia of aspergillus niger were immobilized in calcium alginate gel for the production of citric acid. first, the type of the preactivation medium, together with the preactivation period, was investigated. it was found that a. niger requires a 2-d preactivation period at a 0.05 g/l nh4no3 concentration. second, preactivated cells were used to determine the effects of nitrogen concentration and the flow rate of oxygen and air on the production of citric acid. maximum citric acid production was ... | 2000 | 10949692 |
| kinetic studies and analytical application of cholesterol oxidase and peroxidase immobilized to synthetic polymer. | a method for individual and simultaneous covalent immobilization of cholesterol oxidase and peroxidase to copolymer of acrylonitrile with acrylamide is described. the effect of immobilization on the catalytic properties of the covalently bound enzymes was studied. the immobilized enzymes showed no change in ph optima and an increase in temperature optima, activation energy, and km' compared to data received from experiments with soluble enzymes. a small glass column packed with immobilized multi ... | 2000 | 10949695 |
| construction of a flocculent brewer's yeast strain secreting aspergillus niger beta-galactosidase. | one way of improving heterologous protein production is to use high cell density systems, one of the most attractive being the flocculating yeast production system. also, lactose is available in large amounts as a waste product from cheese production processes. the construction of flocculent and non-flocculent brewer's yeast strains secreting beta-galactosidase and growing on lactose is presented. a plasmid was constructed coding for an extracellular beta-galactosidase of aspergillus niger and h ... | 2000 | 10952011 |
| all eight stereoisomeric d-glyconic-delta-lactams: synthesis, conformational analysis, and evaluation as glycosidase inhibitors. | an efficient and general synthetic route to all eight stereoisomeric d-glycono-delta-lactams has been developed. the strategy involves, as a key step, a stereodivergent delta-lactam formation with configurational retention or inversion at c-4 of a starting gamma-lactone to lead to two epimers of delta-lactam from one parent gamma-lactone. conformations of eight glycono-delta-lactams were examined by x-ray crystallographic analysis and molecular modeling. analyses of conformation and glycosidase- ... | 2000 | 10956466 |
| use of pcr analysis for detecting low levels of bacteria and mold contamination in pharmaceutical samples. | pcr assays were developed and compared to standard methods for quality evaluation of pharmaceutical raw materials and finished products with low levels of microbial contamination. samples were artificially contaminated with less than 10 cfu of escherichia coli, staphylococcus aureus, pseudomonas aeruginosa, and aspergillus niger. bacterial dna was extracted from each enrichment broth by mild lysis in tris-edta-tween 20 buffer containing proteinase k while mold dna was extracted by boiling sample ... | 2000 | 10958971 |
| aryl-alcohol oxidase protein sequence: a comparison with glucose oxidase and other fad oxidoreductases. | aryl-alcohol oxidase (aao), an fad-dependent enzyme involved in lignin degradation, has been cloned from pleurotus eryngii. the aao protein is composed of 593 amino acids, 27 of which form a signal peptide. it shows 33% sequence identity with glucose oxidase from aspergillus niger and lower homology with other oxidoreductases. the predicted secondary structures of both enzymes are very similar. for aao, it is predicted to contain 13 putative alpha-helices and two major beta-sheets, each of the p ... | 2000 | 10962107 |
| purification and characterization of novel antifungal compounds from the sourdough lactobacillus plantarum strain 21b. | sourdough lactic acid bacteria were selected for antifungal activity by a conidial germination assay. the 10-fold-concentrated culture filtrate of lactobacillus plantarum 21b grown in wheat flour hydrolysate almost completely inhibited eurotium repens ibt18000, eurotium rubrum ftdc3228, penicillium corylophilum ibt6978, penicillium roqueforti ibt18687, penicillium expansum idm/fs2, endomyces fibuliger ibt605 and idm3812, aspergillus niger ftdc3227 and idm1, aspergillus flavus ftdc3226, monilia s ... | 2000 | 10966432 |
| otomycosis: a clinicomycologic study. | otomycosis is a common fungal infection of the ear that is seen in the tropical and subtropical regions of the world. we performed mycologic analyses on debris and scraping samples from the external ear canals of 95 patients who had been clinically diagnosed with otomycosis. seventy-one samples (74.7%) were positive for fungal growth; two of these samples contained two fungi, bringing the total number of isolates to 73. the most common pathogens were aspergillus fumigatus (41.1% of all isolates) ... | 2000 | 10969470 |
| in vitro susceptibility testing of filamentous fungi: comparison of etest and reference microdilution methods for determining itraconazole mics. | the performance of the etest for itraconazole susceptibility testing of 50 isolates of filamentous fungi was assessed in comparison with the national committee for clinical laboratory standards (nccls) proposed standard microdilution broth method. the nccls method employed rpmi 1640 broth medium, and mics were read after incubation for 48 h at 35 degrees c. etest mics were determined with rpmi agar containing 2% glucose and with casitone agar and were read after incubation for 24 h (aspergillus ... | 2000 | 10970383 |
| fungal surveillance of an open haematology ward. | air sampling and surveillance cultures for fungi were performed in a scottish general haematology ward over a five-month period in 1997. the mean total fungal count from the air sampling appeared to be correlated with the number of patients colonized by aspergillus. the most commonly isolated species were aspergillus versicolor, a. fumigatus and a. niger. rooms with portable air filtration units had significantly lower total fungal counts than the others. swabs were taken from 70 patients (mean ... | 2000 | 10973746 |
| phytase activity in aspergillus fumigatus isolates. | extracellular phytase from aspergillus fumigatus isolates was characterized and their genes were cloned and sequenced. based on their banding pattern in sds-page all phytases were found to be glycosylated and have similar molecular mass. a correlation between lower optimum ph (4.0) and a higher optimum temperature (70 degrees c) was found in these enzymes. all enzymes characterized displayed a lower specific activity for phytic acid and were more susceptible to proteolytic degradation than the a ... | 2000 | 10973795 |
| overexpression of protein disulfide isomerase in aspergillus. | one of the major problems with the production of biotechnologically valuable proteins has been the purification of the product. for escherichia coli and saccharomyces cerevisiae, there are several techniques for the purification of intracellular proteins, but these are time consuming and often result in poor yields. purification can be considerably facilitated, if the product is secreted from the host cell. in the work presented, we have constructed an expression vector (psgnh2) for the secretio ... | 2000 | 10977899 |
| cloning of a sugar utilization gene cluster in aspergillus parasiticus. | at one end of the 70 kb aflatoxin biosynthetic pathway gene cluster in aspergillus parasiticus and aspergillus flavus reported earlier, we have cloned a group of four genes that constitute a well-defined gene cluster related to sugar utilization in a. parasiticus: (1) sugr, (2) hxta, (3) glca and (4) nada. no similar well-defined sugar gene cluster has been reported so far in any other related aspergillus species such as a. flavus, a. nidulans, a. sojae, a. niger, a. oryzae and a. fumigatus. the ... | 2000 | 10978525 |
| carboxyl group modification significantly altered the kinetic properties of purified carboxymethylcellulase from aspergillus niger. | carboxymethylcellulase (cmcase) from aspergillus niger niab280 was purified by a combination of ammonium sulphate precipitation, ion-exchange, hydrophobic interaction and gel filtration chromatography on fplc with 9-folds increase in specific activity. native and subunit molecular weights were found to be 36 kda each. the purified cmcase was modified by 1-ethyl-3(3-dimethylaminopropyl) carbodiimide (edc) in the presence of glycinamide for 15 min (gam15) and glycinamide plus cellobiose for 75 min ... | 2000 | 10978768 |
| a simple method for purifying glycosidases: alpha-l-rhamnopyranosidase from aspergillus niger to increase the aroma of moscato wine. | alpha-l-rhamnopyranosidase (rha, ec 3.2.1.40) is an enzyme of considerable importance in food technology for increasing the aroma of wines, musts, fruit juices and other alcoholic beverages. the aim of this research is to study the purification of rha contained in a commercial preparation already used in the winemaking industry. with the procedure adopted, rha recovery values were excellent (ca 85%), comparable with those we found in a previous paper on the purification of other glycosidases suc ... | 2000 | 10978775 |
| new antimicrobial mono- and sesquiterpenes from soroseris hookeriana subsp. erysimoides. | a new monoterpene and a new guaianolide were isolated from the aerial parts of the tibetan medicinal plant soroseris hookeriana subsp. erysimoides (asteraceae), in addition to (1r,4r,5r)-5-hydroxybornan-2-one 5-o-beta-d-glucopyranoside, beta-sitosterol, daucosterol, diosmetin, isoluteolin, p-methoxybenzoic acid, isovanillic acid, two phenylmethanol derivatives (vanilioloside and phenylmethanol glucopyranoside), and five guaianolides [3 beta,8 beta-dihyroxyguaia-4(15),10(14),11(13)-triene-12,6 al ... | 2000 | 10985081 |
| look before you clone. a comment on 'properties of aspergillus niger citrate synthase and effects of cita overexpression on citric acid production' by g.j.g ruijter, h. panneman, d.-b. xu and j. visser, fems microbiol. lett. 184 (2000) 35-40. | | 2000 | 10991634 |
| triphenyltin salicylate-antimicrobial effect and resistance--the pyrophosphatase connection. | the effect of triphenyltin salicylate (tps) was tested against six bacteria, escherichia coli, staphylococcus aureus, shigella flexneri, pseudomonas aeruginosa, klebsiella pneumoniae and salmonella typhi and five fungi, aspergillus flavus, aspergillus fumigatus, aspergillus niger, rhodotorula spp. and saccharomyces spp. sensitivity tests were determined with 5-500 microg/ml of tps. all organisms were sensitive to the compound except klebsiella pneumoniae, pseudomonas aeruginosa, rhodotorula spp. ... | 2000 | 10995071 |
| importance of enzyme purity and activity in the measurement of total dietary fiber and dietary fiber components. | a study was made of the effect of the activity and purity of enzymes in the assay of total dietary fiber (aoac method 985.29) and specific dietary fiber components: resistant starch, fructan, and beta-glucan. in the measurement of total dietary fiber content of resistant starch samples, the concentration of alpha-amylase is critical; however, variations in the level of amyloglucosidase have little effect. contamination of amyloglucosidase preparations with cellulase can result in significant und ... | 2000 | 10995129 |
| active site generation of a protonically unstable suicide substrate from a stable precursor: glucose oxidase and dibromonitromethane. | bromonitromethane is an inefficient suicide substrate for glucose oxidase (in contrast to the case of ch(3)ccl=no(2)(-) and d-amino acid oxidase) because, in the enzyme-substrate encounter step, the required ionization states of enzyme (eh(0)(+), pk(a) approximately 3.5) and substrate (chbr=no(2)(-), pk(a) approximately 8.3) cannot be highly populated simultaneously. because reprotonation of chbr=no(2)(-) is rapid at the ph value used for the assay of glucose oxidase, presentation of the enzyme ... | 2000 | 10995249 |
| characteristics of fungal growth in soft contact lenses. | six fungal species (fusarium sp, exophiala jeanselmei, penicillium spp, aspergillus niger, paecilomyces spp, and alternaria spp) were used to inoculate soft contact lenses. four types of soft lenses were used: high-water (58%) and low-water (38%) content lenses and lenses that were unworn or worn for 1 day. the fungi displayed a range of macroscopic and microscopic features that allowed differentiation of species. there was no statistically significant effect of lens water content on growth rate ... | 2000 | 10996761 |
| assay of the inhibitory effect of pentachlorophenol and formaldehyde on mycelial growth and development of reproductive structures in aspergillus niger. | the biological activity of the antifungal agents pentachlorophenol (as sodium pentachlorophenolate) and formaldehyde was evaluated by changes in the development of fungal structures following a placement of test strips inoculated with aspergillus niger conidia on a nutrient agar with the toxicant. the method allows a quantitative assessment of biological activity measured as the development of vegetative structures (growth of the mycelium) by metric, and the development of reproductive structure ... | 1999 | 10997134 |
| production of aspergillus niger catalase under various stress conditions. | the conidia of aspergillus niger were cultured under various stress conditions. the highest yield of catalase activity was obtained after addition 1.2 m nacl to 6-h-old culture, which improved the activity of the enzyme by about 2.8-fold in comparison with the control medium without this depressor. a significantly lower increase (1.3- to 1.7-fold) in catalase activity was reached when spores were incubated under oxidative stress (100-200 mm h2o2) or at low ph (2 and 3). respiratory activities in ... | 2000 | 10997490 |
| a glucoamylase::gfp gene fusion to study protein secretion by individual hyphae of aspergillus niger. | although aspergillus niger is used as a host for heterologous protein production, yields are generally lower than those obtained for homologous proteins. mechanisms of protein secretion and the secretory pathway in filamentous fungi are poorly characterised, although there is evidence to suggest that secretion occurs by a mechanism similar to that in other eukaryotes, but with proteins destined for secretion being directed to the hyphal tip. we report on a method using a glucoamylase: gfp gene f ... | 2000 | 11000429 |
| expression of human lymphotoxin alpha in aspergillus niger. | a gene-fusion expression strategy was applied for heterologous expression of human lymphotoxin alpha (ltalpha) in the aspergillus niger ab1.13 protease-deficient strain. the ltalpha gene was fused with the a. niger glucoamylase gii-form as a carrier-gene, behind its transcription control and secretion signals. special attention was paid to the influence of different codon usage on secretion of protein. in the case of human tumor necrosis factor alpha (tnfalpha) a dramatic change of secretion has ... | 2000 | 11005622 |
| rapid and sensitive plate method for detection of aspergillus fumigatus. | the routine identification of aspergillus fumigatus in clinical samples involves, apart from direct examination, the isolation of the organism on a plate followed by its microscopic characterization. this approach lacks sensitivity, specificity, and speed. a new procedure has been developed combining microcolony formation on a nylon membrane filter at 45 degrees c with the detection of a specific 4-methylumbelliferyl-alpha-l-arabinopyranoside cleaving enzyme activity in digitonin permeabilized c ... | 2000 | 11015405 |
| the use of transgenic yeasts expressing a gene encoding a glycosyl-hydrolase as a tool to increase resveratrol content in wine. | resveratrol, a phenolic compound produced in grapes, exhibits properties that may contribute to the reduction of the incidence of coronary heart disease and other human health related processes. recombinant yeast strains expressing the aspergillus niger abfb gene encoding an alpha-l-arabinofuranosidase or the candida molischiana bgin gene encoding a beta-glucosidase have been used in vinifications as tools to increase the resveratrol content of white wine. glycosylated resveratrol isomers (trans ... | 2000 | 11020039 |
| yanuthones: novel metabolites from a marine isolate of aspergillus niger. | | 2000 | 11031048 |
| isolation and serological analyses of fungal melanins. | melanins are notoriously difficult to work with because of their unique physical and chemical properties. the study of melanins is hampered by the scarcity of melanin-specific reagents and serological techniques. in this study we describe modifications to the standard method for the isolation of melanins from in vitro-melanized fungal cells and detail the optimization of serological techniques for the study of melanin compounds. the isolation procedure involves the digestion of melanized cells w ... | 2000 | 11033020 |
| roles of nadph-p450 reductase in the o-deethylation of 7-ethoxycoumarin by recombinant human cytochrome p450 1b1 variants in escherichia coli. | four human cytochrome p450 1b1 (cyp1b1) allelic variants were purified from membranes of escherichia coli in which respective cyp1b1 cdnas and human nadph-p450 reductase cdna have been introduced. purified cyp1b1 variants were used to reconstitute 7-ethoxycoumarin o-deethylation activities with purified rabbit liver or recombinant (rat) nadph-p450 reductase in the phospholipid vesicles and compared with those catalyzed by cyp1b1 enzymes in the membranes of e. coli in monocistronic (by adding the ... | 2000 | 11035953 |
| comparison of capillary and test tube procedures for analysis of thermal inactivation kinetics of mold spores. | characteristics of capillary and test tube procedures for thermal inactivation kinetic analysis of microbial cells were studied for mold spores. during heating, capillaries were submerged in a water bath and test tubes were held with their caps positioned above the level of the heating medium. thermal inactivation curves of aspergillus niger spores in capillaries at around 60 degrees c consisted of a shoulder and a fast linear decline, whereas curves in test tubes consisted of a shoulder, a fast ... | 2000 | 11041141 |
| molecular cloning and targeted deletion of pep2 which encodes a novel aspartic proteinase from aspergillus fumigatus. | an aspartic proteinase pep2 [ec 3.4.23.25] was purified from a cell wall fraction of aspergillus fumigatus. the enzyme, which showed a broad range of activity from ph 2.0 to 7.0 and migrated as a single band of 39 kda in sds-page, was not detected in the culture supernatant. a specific gene probe was designed on the basis of the n-terminal sequence of the native protein, and the pep2 genomic and cdna were isolated from corresponding libraries. the deduced amino acid sequence of pep2 consists of ... | 2000 | 11043985 |
| a new pentanorlanostane derivative, cladosporide a, as a characteristic antifungal agent against aspergillus fumigatus, isolated from cladosporium sp. | in the course of searching for new antifungal agents, a new pentanorlanostane derivative, cladosporide a (1), was isolated along with ergosterol, ergosterol peroxide and 23,24,25,26,27-pentanorlanost-8-ene-3beta,22-diol (2) from cladosporium sp. as a characteristic antifungal agent against the human pathogenic filamentous fungus aspergillus fumigatus. the structure of 1 was established as 3beta,22-dihydroxy-23,24,25,26,27-pentanorlanostane-29-al by spectroscopic and chemical investigation and x- ... | 2000 | 11045443 |
| beta-glucosidases from five black aspergillus species: study of their physico-chemical and biocatalytic properties. | five black aspergillus strains (a. aculeatus, a. foetidus, a. japonicus, a. niger, and a. tubingensis) were cultivated on crude wheat arabinoxylan as the carbon source under defined ph, temperature, and oxygen conditions. protein and beta-glucosidase content differed remarkably within the obtained culture filtrates, of which eleven beta-glucosidases were isolated. seven beta-glucosidases were purified to apparent electrophoretic homogeneity using anion-exchange and gel-permeation chromatography. ... | 2000 | 11052758 |
| comparison of the efficacies of a novel aspergillus niger mycelium with separate and combined effectiveness of phytase, acid phosphatase, and pectinase in dephosphorylation of wheat-based feeds fed to growing broilers. | efficacies of phytase, phosphorolytic enzymes (phytase + acid phosphatase), an enzymic "cocktail" (phytase + acid phosphatase + pectinase + citric acid), a novel aspergillus niger (fungal) mycelium (fm), and fm enriched in phytase and antioxidants were investigated in growing broilers (days 1 to 21) fed wheat-based diets. broilers were fed the following seven diets at 0.69% ca: 1) a negative control diet, 0.17% nonphytate p (npp); 2) diet 1 + 750 phytase units/kg diet; 3) diet 1 + 750 phytase un ... | 2000 | 11055850 |
| impact of phosphate-solubilizing fungi on the yield and phosphorus-uptake by wheat and faba bean plants. | three fungal isolates (phosphate-dissolvers), aspergillus niger, a. fumigatus and penicillium pinophilum were isolated from the rhizosphere of different plants grown in ismailia and south sinai governorates. they effectively solubilized rock phosphate or tricalcium phosphate in pikovskaya's liquid medium. in pot and column experiments, they significantly reduced ph and increased available phosphorus in the soil treated with either rock phosphate or superphosphate. the yield components of wheat a ... | 2000 | 11061191 |
| comparison of phytase from genetically engineered aspergillus and canola in weanling pig diets. | ninety-six crossbred pigs with an average weight of 9.0 kg were used in a 5-wk trial to compare the efficacy of genetically engineered aspergillus ficuum phytase, expressed in aspergillus niger (natuphos) or in canola seed (phytaseed), for enhancing the utilization of phytate p in corn-soybean meal-based diets fed to young pigs and to evaluate the safety of phytaseed phytase. three levels of the two sources of phytase (250, 500, or 2,500 u/kg of diet) were added to a corn-soybean meal basal diet ... | 2000 | 11063311 |
| simultaneous purification and immobilization of aspergillus niger xylanase on the reversibly soluble polymer eudragit(tm) l-100. | the non-covalent immobilization of a commercial preparation of xylanase from a. niger was carried out on a reversibly soluble-insoluble enteric polymer eudragit(tm) l-100. the immobilization of the xylanase activity by adsorption was simultaneously accompanied by removal of cellulase activity since the latter did not bind to the polymer. thus, the soluble enzyme derivative may be useful for treatment of paper pulp bleaching in paper industry. the immobilized xylanase retained 60% of its activity ... | 2000 | 11064049 |
| "oxidative stress" response in submerged cultures of a recombinant aspergillus niger (b1-d). | a recombinant strain of aspergillus niger (b1-d), engineered to produce the marker protein hen egg white lysozyme, was investigated with regard to its susceptibility to "oxidative stress" in submerged culture in bioreactor systems. the culture response to oxidative stress, produced either by addition of exogenous hydrogen peroxide or by high-dissolved oxygen tensions, was examined in terms of the activities of two key defensive enzymes: catalase (cat) and superoxide dismutase (sod). batch cultur ... | 2000 | 11064335 |
| a chromogenic substrate for a beta-xylosidase-coupled assay of alpha-glucuronidase. | 4-nitrophenyl 2-(4-o-methyl-alpha-d-glucopyranuronosyl)-beta-d-xylopyranoside obtained on deesterification of 4-nitrophenyl 2-o-(methyl 4-o-methyl-alpha-d-glucopyranosyluronate)-beta-d-xylopyranoside (hirsch et al., carbohydr. res. 310, 145-149, 1998) was found to be an excellent substrate for the measurement of hemicellulolytic alpha-glucuronidase activity. a new precise alpha-glucuronidase assay was developed by coupling the alpha-glucuronidase-catalyzed formation of 4-nitrophenyl beta-d-xylop ... | 2000 | 11067752 |
| aspergillosis among people infected with human immunodeficiency virus: incidence and survival. adult and adolescent spectrum of hiv disease project. | aspergillosis is a life-threatening fungal infection in immunocompromised people, including people infected with human immunodeficiency virus (hiv). we determined the incidence of aspergillosis among hiv-infected people and survival after aspergillosis diagnosis by use of a national hiv surveillance database. among 35,252 hiv-infected patients, the incidence of aspergillosis was 3.5 cases per 1000 person-years (p-y; 95% confidence interval [ci], 3.0-4.0 per 1000 p-y). incidence was higher among ... | 2000 | 11073760 |
| cassine, an antimicrobial alkaloid from senna racemosa. | the leaves of senna racemosa yielded the piperidine alkaloid cassine and an inositol methyl ether. antimicrobial screening of the compounds revealed antibacterial activity of cassine with minimum inhibitory concentrations of 2.5 mg/ml for staphylococcus aureus and bacillus subtilis and 5.0 mg/ml for candida albicans. | 2000 | 11077177 |
| synthesis and biological activity of alpha-methylene-gamma-lactones as new aroma chemicals. | seven kinds of alpha-methylene-gamma-lactones with an alkyl group at the c-4 position were synthesized according to a previously described method, with yields of 28-34%. these alpha-methylene-gamma-lactones had characteristic and unique odors. all alpha-methylene-gamma-lactones added a roast-like odor to materials. the antimicrobial effects of alpha-methylene-gamma-lactones were investigated by using a paper disk diffusion method. the results showed the alpha-methylene-gamma-lactones inhibited t ... | 2000 | 11087493 |
| antifungal activity of new 1,3,4-oxadiazolo[3,2-a]-s-triazine-5, 7-diones and their 5-thioxo-7-ones. | n(1)- and n(3)-(4-fluorophenyl) ureas (iii a-e) were cyclocondensed with ethyl chloroformate and cs(2)/koh to yield 2-aryl-6-(4-fluorophenyl)-1,3,4-oxadiazolo[3,2-a]-s-triazine-5, 7-diones (iva-e) and their 5-thioxo-7-ones (va-e), respectively. the compounds iii-v(a-e) have been compared with dithane m-45 for their fungitoxic action against a. niger and f. oxyporum, and the results have been correlated with the structural features of the tested compounds. | 2000 | 11087503 |