| some kinetic studies on cytidine aminohydrolase activity from aspergillus niger nrrl3. | cell free extract of nitrate-grown aspergillus niger nrrl3 catalyzed the hydrolytic deamination of cytidine out of the tested bases, their nucleosides and nucleotides to uridine maximally at ph 7 and at 50 degrees c. the deaminating activity seems to be specific for cytidine, as the extracts could not deaminate amp, gmp, cmp, adenosine, guanosine, adenine, guanine, and cytosine. maximum activity of cytidine deaminase was achieved in tris-hcl buffer at concentration of 0.15 m. incubation of the e ... | 1998 | 10333559 |
| expression, purification, and characterization of the recombinant calcium-binding equine lysozyme secreted by the filamentous fungus aspergillus niger: comparisons with the production of hen and human lysozymes. | equine lysozyme (eql) has been expressed from a synthetic gene and secreted from a heterologous host, the filamentous fungus aspergillus niger. by including 100 mm ca2+ in the growth medium, secreted yields of more than 50 mg/liter could be achieved using polyvinylpyrrolidone (pvp) complete medium. in a soya medium yields of up to 150 mg/liter were achieved. the production of recombinant human lysozyme (hul) from a. niger with yields of over 40 mg/liter was also achieved using pvp medium. additi ... | 1999 | 10336875 |
| differential expression of three alpha-galactosidase genes and a single beta-galactosidase gene from aspergillus niger. | a gene encoding a third alpha-galactosidase (aglb) from aspergillus niger has been cloned and sequenced. the gene consists of an open reading frame of 1,750 bp containing six introns. the gene encodes a protein of 443 amino acids which contains a eukaryotic signal sequence of 16 amino acids and seven putative n-glycosylation sites. the mature protein has a calculated molecular mass of 48,835 da and a predicted pi of 4.6. an alignment of the aglb amino acid sequence with those of other alpha-gala ... | 1999 | 10347026 |
| hilar adenopathy in allergic bronchopulmonary aspergillosis. | a 20-year-old male student developed allergic bronchopulmonary aspergillosis (abpa). computed tomography (ct) of the thorax done to detect central bronchiectasis (cb) for confirmation of diagnosis revealed, in addition, right hilar lymphadenopathy. hilar adenopathy is thought to be rare in abpa and has been documented only once before. because of the finding of hilar adenopathy, the earlier reported patient had to undergo an invasive surgical procedure. | 1999 | 10353584 |
| gallotannin hydrolysis by immobilized fungal mycelia in a packed bed bioreactor. | hydrolysis of gallotannin to gallic acid by immobilized mycelia of aspergillus niger mtcc 282, aspergillus fischerii mtcc 150, fusarium solani mtcc 350 and trichoderma viride mtcc 167 in a packed bed bioreactor was studied. fungal mycelia preinduced with 5 g l-1 gallotannin were immobilized in calcium alginate gel (1.5%) and the resultant beads were packed in a column to a bed volume of 175 mm3. gallotannin dissolved in distilled water was passed through the column and the eluate was recycled af ... | 1999 | 10355367 |
| mineralization of benzo[a]pyrene by marasmiellus troyanus, a mushroom isolated from a toxic waste site. | mycelia from the mushroom marasmiellus troyanus were grown in the presence of radiolabeled benzo[a]pyrene in liquid culture. after 15 days, 8.1% of the label from m. troyanus cultures was recovered in co2 as compared to 1.1% for phanerochaete chrysosporium and 0.2% for aspergillus niger. m. troyanus efficiently transformed b[a]p into water soluble metabolites with 64% of the label recovered in the water soluble fraction as compared to 11.7% for p. chrysosporium and 4.1% for a. niger. glucuronic ... | 1999 | 10356797 |
| biotransformation of hinesol isolated from the crude drug atractylodes lancea by aspergillus niger and aspergillus cellulosae. | biotransformation of the sesquiterpene alcohol hinesol (1) with spasmolytic activity, which was prepared from the rhizome of atractylodes lancea, was carried out by aspergillus niger and aspergillus cellulosae ifo 4040. compound 1 was easily converted to compounds 2-9 by a. niger, and compounds 10 and 11 by a. cellulosae, respectively. their stereostructures were established by a combination of high-resolution nmr spectral analysis, x-ray crystallographic analysis, and chemical reactions such as ... | 1999 | 10361702 |
| glucose 1- and 2-oxidases from fungal strains: isolation and production of monoclonal antibodies. | monoclonal antibodies (mabs) against purified glucose 2-oxidase (ec 1.1.3.10) from coriolus versicolor were raised by hybridoma technology using sp2/0 myeloma cells as a fusion partner. hybrid growth was observed in 42% of culture wells and 30% of these (i.e. 30 culture wells) contained anti-glucose 2-oxidase activity. three positive wells containing hybrid cell lines were selected and cloned twice by the limiting dilution method and two hybridoma clones (e1a5 and e1a6) secreting mabs were selec ... | 1999 | 10361723 |
| antibacterial and antifungal activity of small protein of indigofera oblongifolia leaves. | four fractions from the leaves of indigofera oblongifolia were obtained on sephadex g-25 column chromatography. a single bands of these fractions were detected on poly-acrylamide sds gel electrophoresis. an antibacterial action of small protein peptide was tested against escherichia coli, klebsiella aerogenes, kl. pneumoniae. staphyllococcus aureus, and bacillus subtilis. peptide 3 showed strong inhibitory activity against b. subtilis and aspergillus niger but clear zone of inhibition was also n ... | 1999 | 10363845 |
| microbial metabolism of artemisitene. | studies on the microbial transformation of the sesquiterpene endoperoxide artemisitene have revealed that artemisitene was metabolized by aspergillus niger (nrrl 599) to yield 11-epi-artemisinin, 9 beta-hydroxydeoxy-11-epi-artemisinin and 9 beta-hydroxy-11-epi-artemisinnin. these metabolites were characterized on the basis of their spectral data. | 1999 | 10365449 |
| proliferation of intrahyphal hyphae caused by disruption of csma, which encodes a class v chitin synthase with a myosin motor-like domain in aspergillus nidulans. | we have found that the aspergillus nidulans csma gene encodes a novel protein which consists of an n-terminal myosin motor-like domain and a c-terminal chitin synthase domain (m. fujiwara, h. horiuchi, a. ohta, and m. takagi, biochem. biophys. res. commun. 236:75-78, 1997). to clarify the roles of csma in fungal morphogenesis, we constructed csma null mutants. the growth rate of the mutant colonies was almost the same as that of the wild-type strain, but hyphal growth was severely inhibited when ... | 1999 | 10368147 |
| antimicrobial activity of wedelia trilobata crude extracts. | a biological screening of activity against gram-positive and gram-negative bacteria, yeasts, and fungi of crude extracts from wedelia trilobata is reported. the n-hexane extract showed antibacterial activity against bacillus subtilis, mycobacterium smegmatis, staphylococcus aureus, and staphylococcus epidermidis (gram-positive bacteria); along with proteus vulgaris, pseudomonas aeruginosa, salmonella group c, salmonella paratyphi, and shigella sonnei (gram-negative bacteria). the ethyl acetate e ... | 1999 | 10374253 |
| crea modulates the xlnr-induced expression on xylose of aspergillus niger genes involved in xylan degradation. | the expression of the feruloyl esterase gene faea, the alpha-glucuronidase gene agua, the endoxylanase gene xlnb, and the beta-xylosidase gene xlnd from aspergillus niger on xylose was studied in a wild-type strain and in a crea mutant. a decrease in expression of all four genes was observed with increasing xylose concentrations in the wild-type strain, whereas expression levels in the crea mutant were not influenced. the results in the wild type indicated that xylose concentrations higher than ... | 1999 | 10376490 |
| identification and expression of pen c 2, a novel allergen from penicillium citrinum. | the mould genus, penicillium, is known to be a significant source of environmental aero-allergens. one important allergen from penicillium citrinum, pen c 2, has been identified by means of two-dimensional immunoblotting using ige-containing patients' sera. this novel allergen was cloned, sequenced and expressed in escherichia coli. the cloned cdna encodes a large 457-amino acid protein precursor containing a 16-amino acid signal peptide, a 120-amino acid propeptide and the 321-amino acid mature ... | 1999 | 10377244 |
| molecular cloning of aryl-alcohol oxidase from the fungus pleurotus eryngii, an enzyme involved in lignin degradation. | aryl-alcohol oxidase (aao), an extracellular enzyme characteristic of fungi from the genus pleurotus, constitutes a source for h2o2 required in lignin biodegradation. the gene aao has been cloned, sequenced and characterized for the first time in pleurotus eryngii. both cdna and genomic libraries were screened with probes obtained by pcr using as primers oligonucleotides corresponding to the n-terminus and internal sequences of aao. dna sequences from positive clones showed a unique open reading ... | 1999 | 10377251 |
| in vitro biodegradation study of acetyl and methyl inulins by bifidobacteria and inulinase. | the purpose of this study was to investigate if acetylated and methylated inulins can be degraded by inulinase from aspergillus niger and by bifidobacteria, in order to determine their potential in colonic drug delivery. methyl and acetyl inulins were synthesized by the reaction of inulin (raftiline hp) with methyl sulfate and acetic anhydride, respectively. the degree of substitution (ds) and the structure of the reaction products were confirmed by 13c-nmr. degradation by inulinase was investig ... | 1999 | 10382112 |
| gold(i) complexes as antimicrobial agents. | seven gold complexes were prepared and investigated for biocidal activity against gram-positive and -negative bacteria, fungi and protozoa. all of them were active against the tested microorganisms with the exception of pseudomonas aeruginosa. in many, cases minimum inhibitory concentrations (mic) were well below 1 microgram/ml. the activity is not simply related to the gold content, but also to the nature of both the phosphine and the aminothiol to which the metal is bound. | 1999 | 10384716 |
| characterization of aspergillus niger phosphoglucose isomerase. use for quantitative determination of erythrose 4-phosphate. | phosphoglucose isomerase (pgi) was purified from aspergillus niger and the in vitro kinetic properties of the enzyme were related to its functioning in vivo. a new assay method was developed to study the forward reaction making use of mannitol 1-p dehydrogenase as the coupling enzyme. in this simple assay system mannitol 1-p dehydrogenase converts fructose 6-p and nadh to mannitol 1-p and nad+, respectively. at ph 7.5 the km for glucose 6-p was 0.48 mm, whereas the km for fructose 6-p was 0.32 m ... | 1999 | 10385009 |
| alcoholysis reactions from starch with alpha-amylases. | the ability of alpha-amylases from different sources to carry out reactions of alcoholysis was studied using methanol as substrate. it was found that while the enzymes from aspergillus niger and aspergillus oryzae, two well-studied saccharifying amylases, are capable of alcoholysis reactions, the classical bacterial liquefying alpha-amylases from bacillus licheniformis and bacillus stearothermophilus are not. the effect of starch and methanol concentration, temperature and ph on the synthesis of ... | 1999 | 10386619 |
| nature of oxygen activation in glucose oxidase from aspergillus niger: the importance of electrostatic stabilization in superoxide formation. | glucose oxidase catalyzes the oxidation of glucose by molecular dioxygen, forming gluconolactone and hydrogen peroxide. a series of probes have been applied to investigate the activation of dioxygen in the oxidative half-reaction, including ph dependence, viscosity effects, 18o isotope effects, and solvent isotope effects on the kinetic parameter vmax/km(o2). the ph profile of vmax/km(o2) exhibits a pka of 7.9 +/- 0.1, with the protonated enzyme form more reactive by 2 orders of magnitude. the e ... | 1999 | 10387105 |
| biotransformation of the diperpenoid, isosteviol, by aspergillus niger, penicillium chrysogenum and rhizopus arrhizus. | the biotransformation of isosteviol (ent-16-ketobeyeran-19-oic acid) by three fungi is described. aspergillus niger produced the 7 beta-oh derivative, ent-7 alpha-hydroxy-16-ketobeyeran-19-oic, and the 1 alpha, 7 beta-dioh derivative, ent-1 beta, 7 alpha-dihydroxy-16-ketobeyeran-19-oic acid. the 17-oh compound, ent-17-hydroxy-16-ketobeyeran-19-oic acid, was obtained with penicillium chrysogenum. rhizopus arrhizus produced the 7 beta-oh derivative, ent-7 alpha-hydroxy-16-ketobeyeran-19-oic acid. ... | 1999 | 10389273 |
| characterisation of a starch-hydrolysing enzyme of aspergillus niger. | a uv-induced mutant strain of aspergillus niger (cftri-1105-u9) overproduced a starch-hydrolysing enzyme with properties characteristically different from the known amylases of the fungus. the purified enzyme of 4.0 pi had an apparent molecular mass of 125 kda and it dextrinised starch and then saccharified the dextrins. patterns of the enzyme activity on starch, resulting in glucose at 60 degrees c and glucose, maltose and maltodextrins at 70 degrees c as primary products, suggested significant ... | 1999 | 10390823 |
| a comparison between toxicity tests using single species and a microbial process. | in this study the sensitivity of the acetate mineralization process performed by five strains of microorganisms in soil for the toxicants zn2+ or pcp was calculated from the sensitivity of the contributing species. the species used were a fungus (aspergillus niger cbs 121.49), an actinomycete (streptomyces lividans 66), two gram-negative pseudomonas putida strains (mt-2 and dsm 50026) and a gram-positive strain rhodococcus erythropolis a177. for zinc the ec10 of the process performed by the five ... | 1999 | 10390842 |
| lead mineral transformation by fungi. | pyromorphite (pb5(po4)3cl), the most stable lead mineral under a wide range of geochemical conditions [1], can form in urban and industrially contaminated soils [2] [3] [4] [5]. it has been suggested that the low solubility of this mineral could reduce the bioavailability of lead, and several studies have advocated pyromorphite formation as a remediation technique for lead-contaminated land [3] [5] [6], if necessary using addition of phosphate [6]. many microorganisms can, however, make insolubl ... | 1999 | 10395543 |
| influence of environmental conditions on hyphal morphology in pellets of aspergillus niger: role of beta-n-acetyl-d-glucosaminidase. | the influence of modifications of the environmental conditions of growth on beta-n-acetyl-d-glucosaminidase (ec 3.2.1.30) activity and on hyphal morphological patterns in pellets of aspergillus niger was studied. it was found that changes in the degree of branching and, to a lesser extent, in the number of bulbous cells were directly related to the activity of the enzyme. nevertheless, since beta-n-acetyl-d-glucosaminidase is not the only enzyme involved in the lytic potential of the fungus, the ... | 1999 | 10398828 |
| scale-up of citric acid fermentation by redox potential control | to obtain high citric acid productivity in aspergillus niger fermentation on beet molasses substrate, a certain redox potential profile with two maxima (260 and 280 mv) and two minima (180 and 80 mv) must be maintained. the most effective regulation of redox potential is by regulation of aeration and agitation. it has been shown that control of redox potential by aeration and agitation is a most successful method for scale-up from 10-l laboratory scale to the 100- and 1000-l pilot-plant scale, e ... | 1999 | 10404235 |
| antimicrobial activity of the essential oil of calamintha nepeta and its constituent pulegone against bacteria and fungi. | the chemical composition of the essential oil of calamintha nepeta and its antimicrobial activity against listeria monocytogenes, bacillus cereus, salmonella veneziana, s. paratyphi b. s. typhimurium, fusarium moniliforme, botrytis cinerea, aspergillus niger and pyricularia oryzae have been studied. moreover the main constituents of the oil (limonene, menthone, pulegone, menthol) have been tested against the same microorganisms. only pulegone showed antimicrobial activity, particularly against a ... | 1999 | 10404547 |
| purification and characterization of a highly enantioselective epoxide hydrolase from aspergillus niger. | the epoxide hydrolase from aspergillus niger was purified to homogeneity using a four-step procedure and p-nitrostyrene oxide (pnso) as substrate. the enzyme was purified 246-fold with 4% activity yield. the protein is a tetramer composed of four identical subunits of molecular mass 45 kda. maximum activity was observed at 40 degrees c, ph 7.0, and with dimethylformamide as cosolvent to dissolve pnso. hydrolysis of pnso was highly enantioselective, with an e value (i.e. enantiomeric ratio) of 40 ... | 1999 | 10406946 |
| characterization of the glycosylation of recombinant endopolygalacturonase i from aspergillus niger. | the carbohydrate chains of recombinant endopolygalacturonase i (epg i) from aspergillus niger were characterized using a combination of mass spectrometric techniques. high performance liquid chromatography (hplc) in conjunction with electrospray ionization mass spectrometry was used to separate the components of epg i liberated by trypsin digestion. in-source collision-induced dissociation (cid) was utilized to fragment the digestion products entering the mass spectrometer, and the generation of ... | 1999 | 10407337 |
| lysophosphatidic acid increases intracellular h2o2 by phospholipase d and rhoa in rat-2 fibroblasts. | we have investigated the possible roles of phospholipase d (pld) and rhoa in the production of intracellular h2o2 and actin polymerization in response to lysophosphatidic acid (lpa) in rat-2 fibroblasts. lpa increased intracellular h2o2, with a maximal increase at 30 min, which was blocked by the catalase from aspergillus niger. the lpa-stimulated production of h2o2 was inhibited by 1-butanol or pkc-downregulation, but not by 2-butanol. purified phosphatidic acid (pa) also increased intracellula ... | 1999 | 10420989 |
| necrotizing mycotic vasculitis with cerebral infarction caused by aspergillus niger in a horse with acute typholocolitis. | an 18-year-old morgan mare was presented to the veterinary medical teaching hospital, university of illinois, with a 10-day history of watery diarrhea, depression, and dysphagia. on admission, the animal was severely dehydrated, depressed, and unable to swallow and had no clinical signs of diarrhea. the respiratory and heart rate and body temperature were within normal limits. following fluid therapy, the mare developed severe watery diarrhea and continued to be depressed, incoordinated, and dys ... | 1999 | 10421105 |
| resolution of racemic carboxylic acids via the lipase-catalyzed irreversible transesterification of vinyl esters. | the lipase-catalyzed irreversible transesterification procedure using vinyl esters was applied to the resolution of racemic 2-phenoxypropanoic acids. aspergillus niger lipase showed high enantioselectivities and reasonable reaction rates. the enantioselectivity was found to be affected profoundly by several variables, e.g., the alcohol as nucleophile, the organic solvent used, and the reaction temperature. a gram-scale resolution of (rs)-2-phenoxypropanoic acid was achieved after optimization of ... | 1999 | 10423282 |
| [a neutropenic acute myeloid leukemia patient complicated with chronic otitis media due to aspergillus niger and yeast-like fungi caused by superinfection]. | there have been few reports describing otomycosis in association with compromised hosts. so we report a neutropenic acute myeloid leukemia (aml) patient complicated with otomycosis caused by superinfection. a 51-year-old male was admitted because a third relapse of aml in march 1998. two years ago, he was diagnosed as having chronic otitis media involving the vii cranial nerve due to pseudomonas aeruginosa coinciding with aml. then, he had suffered from a right-sided earache and otic discharge i ... | 1999 | 10423956 |
| [effect of trace metals on cell morphology, enzyme activation, and production of citric acid in a strain of aspergillus wentii]. | data concerning the effect of very low concentrations of metals on citric acid production by microorganisms, as well as on the activity of enzymes presumptively involved in the process, are confuse. the bulk of information was obtained mainly studying selected strains of aspergillus niger. information concerning other citric acid producer filamentous fungi, such as a. wentii, is scanty. in the present article we report the effect of different cations on the growth pattern of a. wentii p1 as well ... | 1999 | 10425661 |
| a facile synthesis of d-glucose-type gem-diamine 1-n-iminosugars: a new family of glucosidase inhibitors. | gem-diamine 1-n iminosugars of d-glucose-type, a new type of glycosidase inhibitors, have been synthesized from siastatin b, isolated from streptomyces culture. 2-trifluoroacetamido-1-n-iminosugar, (2s,3r,4r,5r)-2-trifluoroacetamido-5-hydroxymethylpiperidine -3,4-diol was proved to be a potent inhibitor for alpha-d- and beta-d-glucosidases (ic50 1.9x10(-7) and 4.2x10(-7) m, respectively). 2-acetamido-1-n-iminosugar, (2s,3r,4r,5r)-2-acetamido-5-hydroxymethylpiperidine-3,4-diol also affected these ... | 1999 | 10428397 |
| a group of alpha-1,4-glucan lyase genes from the fungi morchella costata, m. vulgaris and peziza ostracoderma. cloning, complete sequencing and heterologous expression. | we here report genes encoding a newly discovered class of starch- and glycogen-degrading enzyme, alpha-1,4-glucan lyase (ec 4.2.2.13), which degrades starch and glycogen to 1,5-anhydro-d-fructose. two lyases were purified and partially sequenced from the macrofungi morchella costata and m. vulgaris. the obtained lyase amino acid sequences were used to generate pcr primers, which were further used to probe the fungal genomic libraries. two lyase genes (agll1;mo.cos and agll1;mo.vul) from the two ... | 1999 | 10437828 |
| determination of the reaction yield during biotransformation of the volatile and chemically unstable compound beta-ionone by aspergillus niger | biotransformation of beta-ionone by aspergillus niger ifo 8541 was a complex system, due to the low precursor solubility in water (0.88 mol/m(3)) which gave a two-phase liquid system, its high volatility (vapor pressure 7.2 pa), and its poor chemical stability. a dynamic model, considering transfers between organic, aqueous, and gas layers, was established. it also took into account the decrease in organic layer area exchange during a process, due to progressive precursor disappearance. its solv ... | 1999 | 10441361 |
| antifungal effects of different plant extracts and their major components of selected aloe species. | different extracts of both fresh and dry leaves of aloe eru a. berger, a. vera l. webb & berth and a. arborescens mill. were screened for their antifungal activity against aspergillus niger, cladosporium herbarum and fusarium moniliforme. the toxicity of the isolated pure components were evaluated on the tested fungi. a comparative chromatographic study was performed to differentiate between natural components existing in various fractions and extracts of aloe species and specific spray reagents ... | 1999 | 10441780 |
| pullulan production from deproteinized whey by aureobasidium pullulans. | the production of pullulan from deproteinized whey by aureobasidium pullulans p56 was investigated using an adaptation technique and a mixed culture system. the adaptation of a. pullulans and the mixed cultures of a. pullulans and/or lactobacillus brevisx20, debaryomyces hansenii 194 and aspergillus niger did not increase the production of polysaccharide. enzymic hydrolysis of lactose in deproteinized whey gave a higher polysaccharide concentration and polysaccharide yield than acidic hydrolysed ... | 1999 | 10455488 |
| inhibition of food-related pathogenic bacteria by god-transformed penicillium nalgiovense strains. | two strains of penicillium nalgiovense, which carried the god gene of aspergillus niger and had increased glucose oxidase (god) activity compared with the wild-type strain, were tested for their ability to suppress the growth of certain food-related pathogenic bacteria. in contrast to the wild type, which showed no antibacterial effect when grown in mixed culture with different bacteria, the two transformed strains were highly antagonistic. the strain that expressed higher amounts of god in gene ... | 1999 | 10456750 |
| female mating strategy and male brood cannibalism in a sand-dwelling cardinalfish. | i investigated male and female sexual strategies of a cardinalfish, apogon niger, which breeds in sandy areas at sporadic coral colonies. males mouthbrood an egg mass received from one female at a time. because of the lengthy mouthbrooding period, the interspawning interval was shorter for females than for males. females moved between coral colonies to find mates more extensively than did males, and more frequently deserted mates after spawning. the females shortened their interspawning interval ... | 1999 | 10458878 |
| allergic bronchopulmonary aspergillosis due to aspergillus niger without bronchial asthma. | a 65-year-old woman was admitted to our hospital with a dry cough and pulmonary infiltrates. chest radiograph and ct revealed mucoid impaction and consolidations. peripheral blood eosinophilia and elevated serum ige were observed. aspergillus niger was cultured repeatedly from her sputum, but a. fumigatus was not detected. immediate skin test and specific ige (rast) to aspergillus antigen were positive. precipitating antibodies were confirmed against a. niger antigen, but not against a. fumigatu ... | 1999 | 10461089 |
| the exopolygalacturonase from aspergillus tubingensis is also active on xylogalacturonan. | apple-pectin hairy regions were prepared from apple pectin by combined action of the recombinant aspergillus niger enzymes endopolygalacturonase ii and pectin methylesterase and the a. tubigensis exopolygalacturonase. using this enzymically prepared pectin fraction, an additional activity of the a. tubigensis exopolygalacturonase was discovered only when the substrate was chemically saponified and when d-galacturonate, a potent inhibitor of the enzyme, was removed from the incubation mixture. th ... | 1999 | 10467119 |
| flavonol 2,4-dioxygenase from aspergillus niger dsm 821, a type 2 cuii-containing glycoprotein. | flavonol 2,4-dioxygenase, which catalyzes the cleavage of quercetin to carbon monoxide and 2-protocatechuoyl-phloroglucinol carboxylic acid, was purified from culture filtrate of aspergillus niger dsm 821 grown on rutin. it is a glycoprotein (46-54% carbohydrate) with n-linked oligo-mannose type glycan chains. the enzyme was resolved in sds polyacrylamide gels in a diffuse protein band that corresponded to a molecular mass of 130-170 kda. when purified flavonol 2,4-dioxygenase was heated, it dis ... | 1999 | 10469153 |
| occupational ige sensitisation to phytase, a phosphatase derived from aspergillus niger. | phytase is a phosphatase derived from aspergillus niger that enhances phosphate bioavailability in the gut, and therefore has been increasingly used as an animal feed additive since the early 1990s. the aim of this study was to assess whether work related respiratory symptoms among workers in a so called premix factory producing animal feed additives, could be due to type i (mediated by immunoglobulin e (ige) allergic sensitisation to phytase. | 1999 | 10472316 |
| the importance of serine proteinases as aeroallergens associated with asthma. | penicillium and aspergillus species have been identified as prevalent indoor airborne fungi that are associated with extrinsic bronchial asthma. we have recently analyzed the ige-binding components in 8 prevalent penicillium and aspergillus species (p. citrinum, p. notatum, p. oxalicum, p. brevicompactum, a. fumigatus, a. flavus, a. oryzae and a. niger) by immunoblotting and n-terminal amino acid sequence analysis. our results show that the alkaline and/or vacuolar serine proteinases are the maj ... | 1999 | 10474030 |
| inhibitory effect of seven allium plants upon three aspergillus species. | antifungal activity and minimal fungicidal concentration (mfc) of extracts of garlic, bakeri garlic, chinese leek, chinese chive, scallion, onion bulb and shallot bulb against aspergillus niger, a. flavus and a. fumigatus were examined. these allium plants possessed antifungal activity, with garlic showing the lowest mfc. with the exception of scallion, the inhibitory effect of allium plants against three aspergillus species decreased with increasing incubation and heating temperature (p < 0.05) ... | 1999 | 10477070 |
| survey of termite-inhabited soil and mosquito breeding sites in lucknow, india for potential mycopathogens of anopheles stephensi. | during a short survey of soil and mosquito breeding sites in lucknow, india for potential mycopathogen from a period of august-october 1996, 11 species of fungi in 5 genera were isolated using live mosquito larvae as host, aspergillus flavus, a. fumigatus and fusarium semitectum were the most frequently isolated species. other fungi recorded were a. niger, a. ochraceus, a. terreus, a. versicolor, geotrichum candidum, penicillium verrucosum, paecilomyces sp. and fusarium sp. (liseola/elegans comp ... | 1998 | 10481288 |
| the aspergillus niger acua and acub genes correspond to the faca and facb genes in aspergillus nidulans. | mutants in aspergillus niger unable to grow on acetate as a sole carbon source were previously isolated by resistance to 1.2% propionate medium containing 0.1% glucose. acua mutants lacked acetyl-coa synthetase (acs) activity and acub mutants lacked both acs and isocitrate lyase activity. an acua mutant was transformed to the acu+ phenotype with a clone of acs (faca) from aspergillus nidulans. the acub mutant was transformed with the a. niger facb clone which has been identified by cross-hybridi ... | 1999 | 10483720 |
| chemically modified glucose oxidase with enhanced hydrophobicity: adsorption at polystyrene, silica, and silica coated by lipid monolayers. | covalent modification of glucose oxidase from aspergillus niger by the palmitic acid ester of n-hydroxysuccinimide at a molar ratio ester:protein of 56:1 results in the formation of the enzyme derivative with 11 attached palmitic chains. surface hydrophobicity measurements by a fluorescent probe, 8-anilino-1-naphthalenesulfonate, indicate a drastic increase in the hydrophobicity index of glucose oxidase after such a modification. the modified glucose oxidase displays a much higher adsorption aff ... | 1999 | 10489305 |
| fungal utilization of organophosphate pesticides and their degradation by aspergillus flavus and a. sydowii in soil. | fungal species were isolated which utilize organophosphate pesticides, viz. phosphorothioic (pirimiphos-methyl and pyrazophos), phosphorodithioic (dimethoate and malathion), phosphonic (lancer) and phosphoric (profenfos) acid derivatives. pesticide degradation was studied in vitro and in vivo (soil). aspergillus flavus, a. fumigatus, a. niger, a. sydowii, a. terreus, emericella nidulans, fusarium oxysporum and penicillium chrysogenum were isolated from pesticide-treated wheat straw. the number o ... | 1999 | 10489696 |
| expression of amylase and glucose oxidase in the hypopharyngeal gland with an age-dependent role change of the worker honeybee (apis mellifera l.). | worker honeybees change their behaviour from the role of nurse to that of forager with age. we have isolated cdna clones for two honeybee (apis mellifera l.) genes, encoding alpha-amylase and glucose oxidase homologues, that are expressed in the hypopharyngeal gland of forager bees. the predicted amino acid sequence of the putative apis amylase showed 60.5% identity with drosophila melanogaster alpha-amylase, whereas that of apis glucose oxidase showed 23.8% identity with aspergillus niger gluco ... | 1999 | 10491166 |
| the fluorescence emission of the apo-glucose oxidase from aspergillus niger as probe to estimate glucose concentrations. | we developed a new method of glucose sensing using an inactive form of glucose oxidase from aspergillus niger. glucose oxidase was rendered inactive by removal of the fad cofactor. the resulting apo-glucose oxidase still binds glucose as observed from a decrease in its intrinsic tryptophan fluorescence. 8-anilino-1-naphthalenesulfonic acid (ans) was found to bind spontaneously to apo-glucose oxidase as seen from an enhancement of the ans fluorescence. the steady state intensity of the bound ans ... | 1999 | 10491329 |
| a modular cinnamoyl ester hydrolase from the anaerobic fungus piromyces equi acts synergistically with xylanase and is part of a multiprotein cellulose-binding cellulase-hemicellulase complex. | a collection of clones, isolated from a piromyces equi cdna expression library by immunoscreening with antibodies raised against affinity purified multienzyme fungal cellulase-hemicellulase complex, included one which expressed cinnamoyl ester hydrolase activity. the p. equi cinnamoyl ester hydrolase gene (esta) comprised an open reading frame of 1608 nt encoding a protein (esta) of 536 amino acids and 55540 da. esta was modular in structure and comprised three distinct domains. the n-terminal d ... | 1999 | 10493932 |
| spectrophotometric kinetic study and analytical implications of the glucose oxidase-catalyzed reduction of [miii(ll)2cl2]+ complexes by d-glucose (m = os and ru, ll = 2,2'-bipyridine and 1,10-phenanthroline type ligands). | glucose oxidase-catalyzed reduction of cis-[miii(ll)2cl2]+ (m = os and ru) complexes to cis-[mii(ll)2cl2] (ll = 2,2'-bipyridine and 1,10-phenanthroline type ligands) by d-glucose is a first-order process in the complex and the enzyme in aqueous buffered solution. the reaction follows michaelis-menten kinetics in d-glucose and the rate is independent of d-glucose concentration above 0.03 m. the reactivity decreases in the series [ru(bpy)2cl2]+ > [os(phen)2cl2]+ > [os(4,4'-me2bpy)2cl2]+ > [os(4,7- ... | 1999 | 10499089 |
| guaianolides from centaurea nicolai: antifungal activity. | a new guaianolide, 3-deacetyl-9-o-acetylsalograviolide a, along with four known closely related lactones, salograviolide a, 9-o-acetylsalograviolide a, kandavanolide and salograviolide b were detected in the aerial parts of the flowering plant centaurea nicolai. antifungal tests performed on salograviolide a and its 9-o-acetyl and 3-o-deacetyl-9-o-acetyl derivatives revealed inhibitory activity against aspergillus niger, a. ochraceus, penicillium ochrochloron, cladosporium cladosporoides, fusari ... | 1999 | 10501024 |
| construction and application of mcbl plate for facilitation of chromosome recombination in fungi. | a medium with camphor and benomyl mcbl plate was designed and constructed based on the proposed mechanism that d-camphor could induce the fusion of nuclear membrane while benomyl could induce the nondisjunctional recombination of chromosome in fungi. this so-called co-induction plate consisted of 0.1% d-camphor (w/v) and 0.5 microgram/l benomyl contained in czapek's minimal medium. the precautions to be taken in the construction procedure of this plate was described in detail. one typical exampl ... | 1998 | 10503074 |
| determination of serum glucose with alkylamine glass bound glucose oxidase. | serum glucose was analyzed using glucose oxidase from aspergillus niger immobilized to alkylamine glass (pore diameter 55 nm) by the glutaraldehyde coupling method. the minimum detection limit was 3.6 mg/100 ml sample. the recovery of added glucose was 95%. a good correlation (r = 0.808) was found between glucose values obtained by a standard commercial method and the present method. | 1998 | 10503081 |
| promoter-tagged restriction enzyme-mediated insertion (pt-remi) mutagenesis in aspergillus niger. | promoter-tagged restriction enzyme-mediated insertion (pt-remi) mutagenesis was performed in the fungus aspergillus niger, using a plasmid containing a strong transcriptional promoter. two dna-tagged mutants were analyzed in detail. a white-spored mutant was shown to contain a plasmid insertion that disrupted a gene that shows a high degree of homology to the polyketide synthase gene wa of a. nidulans. a morphological mutant was shown to contain a plasmid insertion in the 5' upstream region of a ... | 1999 | 10503533 |
| effect of oxygen enrichment on morphology, growth, and heterologous protein production in chemostat cultures of aspergillus niger b1-d. | the response of steady state chemostat cultures of a recombinant aspergillus niger (b1-d), secreting both a heterologous enzyme (hen egg white lysozyme [hewl]) and a native enzyme (glucoamylase), to varying levels of o2 enrichment of the process gas was evaluated. formation of both the native and the foreign enzyme increased with increasing o2 supply. conversely, biomass levels and total extracellular protein levels were generally not increased under o2 enriched conditions. two distinct micromor ... | 1999 | 10506417 |
| two cellobiohydrolase-encoding genes from aspergillus niger require d-xylose and the xylanolytic transcriptional activator xlnr for their expression. | two cellobiohydrolase-encoding genes, cbha and cbhb, have been isolated from the filamentous fungus aspergillus niger. the deduced amino acid sequence shows that cbhb has a modular structure consisting of a fungus-type cellulose-binding domain (cbd) and a catalytic domain separated by a pro/ser/thr-rich linker peptide. cbha consists only of a catalytic domain and lacks a cbd and linker peptide. both proteins are homologous to fungal cellobiohydrolases in family 7 of the glycosyl hydrolases. nort ... | 1999 | 10508057 |
| dephosphorylation of phytate by using the aspergillus niger phytase with a high affinity for phytate. | a phytase (ec 3.1.3.8) with a high affinity for phytic acid was found in aspergillus niger sk-57 and purified to homogeneity in four steps by using ion-exchange chromatography (two types), gel filtration, and chromatofocusing. sodium dodecyl sulfate-polyacrylamide gel electrophoresis of the purified enzyme gave a single stained band at a molecular mass of approximately 60 kda. the michaelis constant of the enzyme for phytic acid (18.7 +/- 4.6 microm) was statistically analyzed. in regard to the ... | 1999 | 10508107 |
| effect of ph on hen egg white lysozyme production and evolution of a recombinant strain of aspergillus niger. | an aspergillus niger strain (b1) transformed to produce mature hen egg white lysozyme (hewl) from a glucoamylase fusion protein under control of the a. niger glucoamylase promoter was grown in glucose-limited chemostat culture at a dilution rate of 0.07 h-1 at various ph values. maximum hewl production (9.3 mg g-1; specific production rate = 0.65 mg g-1 per h) was obtained at ph 4.5. however, in chemostat culture, hewl production was not stable at any ph tested. after 240 h in steady state, spec ... | 1999 | 10510855 |
| isolation and characterization of a novel antifungal peptide from aspergillus niger. | a novel antifungal peptide (termed as anafp) was isolated from the culture supernatant of the filamentous fungi, aspergillus niger. the whole amino acid sequence of anafp was determined and the peptide was found to be composed of a single polypeptide chain with 58 amino acids including six cysteine residues. the peptide shows some degree of sequence homology to a cysteine-rich antifungal peptides reported from the seeds of sinapis alba and arabidopsis thaliana or the extracellular media of asper ... | 1999 | 10512732 |
| microbial hydroxylation of natural drimenic lactones. | incubation of confertifolin and isodrimenin with mucor plumbeus, aspergillus niger or rhizopus arrhizus gave in good yields the corresponding 3 beta-hydroxy derivatives. from isodrimenin, the known natural 7 alpha-hydroxy derivative (futronolide) was also obtained and its structure was definitely established by x-ray crystallographic study of its acetate derivative. | 1999 | 10513402 |
| oxalic acid production by aspergillus niger: an oxalate-non-producing mutant produces citric acid at ph 5 and in the presence of manganese. | the external ph appeared to be the main factor governing oxalic acid production by aspergillus niger. a glucose-oxidase-negative mutant produced substantial amounts of oxalic acid as long as the ph of the culture was 3 or higher. when ph was decreased below 2, no oxalic acid was formed. the activity of oxaloacetate acetylhydrolase (oah), the enzyme believed to be responsible for oxalate formation in a. niger, correlated with oxalate production. oah was purified from a. niger and characterized. o ... | 1999 | 10517610 |
| the antifungal activity of 2,2'-diamino-4,4'-dithiazole derivatives is due to the possible inhibition of lanosterol-14-alpha-demethylase. | aryl/alkyl sulfonylamido-, arylsulfenylamido-, arylcarboxamido- and ureido/thioureido/guanidino derivatives of 2,2'-diamino-4,4'-dithiazole were prepared by reaction of the title compound with sulfonyl/sulfenyl halides, sulfonic acid anhydrides, acyl chlorides, tosyl isocyanate, aryl/allyl isocyanates or isothiocyanates. mono- as well as bis-derivatized compounds have been obtained. several of the newly synthesized compounds act as effective antifungal agents against aspergillus and candida spp. ... | 1998 | 10520759 |
| 1.68-a crystal structure of endopolygalacturonase ii from aspergillus niger and identification of active site residues by site-directed mutagenesis. | polygalacturonases specifically hydrolyze polygalacturonate, a major constituent of plant cell wall pectin. to understand the catalytic mechanism and substrate and product specificity of these enzymes, we have solved the x-ray structure of endopolygalacturonase ii of aspergillus niger and we have carried out site-directed mutagenesis studies. the enzyme folds into a right-handed parallel beta-helix with 10 complete turns. the beta-helix is composed of four parallel beta-sheets, and has one very ... | 1999 | 10521427 |
| production of calcium gluconate by fermentation. | calcium gluconate production by aspergillus niger was investigated in shake flask, rolling shaker, air-lift reactor and stirred reactor. growth pattern of the organism and fermentation conditions determined the yield of the product. high calcium gluconate production was achieved in air-lift reactor with pellet form of cell growth at moderate specific growth rate and biomass concentration. in another variation of air-lift reactor, when calcium carbonate was confined to a cellulose membrane, calci ... | 1999 | 10522163 |
| stabilization of cellobiase by covalent coupling to soluble polysaccharide. | cellobiase from aspergillus niger was glycosylated by covalent coupling to cyanogen bromide activated dextran. the conjugated enzyme retained 62% of the original specific activity exhibited by the native cellobiase. the optimum ph as well as the ph stability of the conjugated form remain almost the same as for the native enzyme. compared to the native enzyme, the conjugated form exhibited a higher optimal reaction temperature and energy of activation, a higher k(m) (michaelis constant) and lower ... | 1999 | 10522387 |
| successful treatment of post-influenza pseudomembranous necrotising bronchial aspergillosis with liposomal amphotericin, inhaled amphotericin b, gamma interferon and gm-csf. | a case of aspergillus tracheobronchitis following influenza a infection in an immunocompetent 35 year old woman is described that required prolonged mechanical ventilation for airways obstruction. treatment included liposomal amphotericin, inhaled amphotericin, gamma interferon and gm-csf. liposomal amphotericin therapy was associated with reversible hepatosplenomegaly. inhaled corticosteroids with continued antifungal therapy were used for the management of severe recurrent airway obstruction. ... | 1999 | 10525567 |
| synthesis of 9z,11e-octadecadienoic and 10e,12z-octadecadienoic acids, the major components of conjugated linoleic acid. | linoleic acid was efficiently converted into the two major components of conjugated linoleic acid, 9z,11e-octadecadienoic (1a) and 10e,12z-octadecadienoic acid (1b) using either the superbase (n-butyllithium/potassium tert-butoxide) or by simply refluxing with koh in 1-butanol. in turn, 1a and 1b were separated from each other using the lipase from aspergillus niger via stereoselective esterification in 1-butanol. this enzyme has a preference for the 9z,11e isomer, 1a, and has excellent selectiv ... | 1999 | 10529100 |
| roles of rhoa and phospholipase a2 in the elevation of intracellular h2o2 by transforming growth factor-beta in swiss 3t3 fibroblasts. | we have investigated the mechanisms by which transforming growth factor-beta (tgf-beta) increased intracellular h2o2 in swiss 3t3 fibroblasts. increase of intracellular h2o2 by tgf-beta was maximal at 30 min and blocked by catalase from aspergillus niger. scrape-loading of c3 transferase, which down-regulated rhoa, inhibited the production of h2o2 in response to tgf-beta. tgf-beta stimulated release of arachidonic acid, which was completely inhibited by mepacrine, a phospholipase a2 inhibitor. m ... | 1999 | 10530876 |
| synthesis and antifungal activity of coumarins and angular furanocoumarins. | angelicin, a naturally occurring furanocoumarin, that showed antifungal activity, was considered as a lead structure for a group of synthetic coumarins. antifungal activities of the synthesized coumarins and angelicin derivatives were reported against candida albicans, cryptococcus neoformans, saccharomyces cerevisiae and aspergillus niger. human cell line cytotoxicity of several coumarins was evaluated against kb cells. angelicin and several potent antifungals showed to be non-toxic in this ass ... | 1999 | 10530942 |
| immunoaffinity layering of enzymes. stabilization and use in flow injection analysis of glucose and hydrogen peroxide. | a general procedure for the high yield immobilization of enzymes with the help of specific anti-enzyme antibodies is described. polyclonal antibodies were raised against aspergillus niger glucose oxidase and horseradish peroxidase in rabbits and the gamma globulin (igg) fraction from the immune sera isolated by ammonium sulphate fractionation followed by ion-exchange chromatography. immobilization of glucose oxidase and horseradish peroxidase was achieved by initially binding the enzymes to a se ... | 1999 | 10531650 |
| amylose-like polysaccharide accumulation and hyphal cell-surface structure in relation to citric acid production by aspergillus niger in shake culture. | when 120 mg glucose/ml was used as a carbon source, in shake culture aspergillus niger yang no. 2 maximally produced only 15.4 mg citric acid/ml but accumulated 3.0 mg extracellular polysaccharide/ml. the polysaccharide secreted by mycelia of yang no. 2 in shake culture was confirmed to be an amylose-like alpha-1,4-glucan by hydrolysis analysis with acid, amylase and glucoamylase. however, in static cultures, such as semisolid and surface cultures free from physical stresses caused by shaking da ... | 1999 | 10531655 |
| fungal morphology in submerged cultures and its relation to glucose oxidase excretion by recombinant aspergillus niger. | the effect of culture conditions such as medium composition and shear stress on the fungal pellet morphology in shake-flask cultures and its relation to glucose oxidase (god) excretion by recombinant aspergillus niger nrrl 3 (god 3-18) was investigated. it was shown that culture conditions resulting in the formation of smaller fungal pellets with an increased mycelial density result in higher yields of exocellular god. the pellets obtained in shake-flask cultures showed distinct layers of myceli ... | 1999 | 10533711 |
| steady-state inhibitory kinetic studies on the ligand binding modes of aspergillus niger glucoamylase. | inhibitory activities of 1-deoxynojirimycin and gluconolactone on aspergillus niger glucoamylase were studied in relation to the subsite structure of the enzyme. although both of these inhibitors are considered to bind at subsite 1 of the enzyme active site, 1-deoxynojirimycin showed competitive type inhibition but gluconolactone was a mixed type (or noncompetitive type) inhibitor for the hydrolysis of p-nitrophenyl alpha-d-glucoside. the former type of inhibition suggested that the main binding ... | 1999 | 10540741 |
| homology between egg white sulfhydryl oxidase and quiescin q6 defines a new class of flavin-linked sulfhydryl oxidases. | the flavin-dependent sulfhydryl oxidase from chicken egg white catalyzes the oxidation of sulfhydryl groups to disulfides with the reduction of oxygen to hydrogen peroxide. reduced proteins are the preferred thiol substrates of this secreted enzyme. the egg white oxidase shows an average 64% identity (from randomly distributed peptides comprising more than 30% of the protein sequence) to a human protein, quiescin q6, involved in growth regulation. q6 is strongly expressed when fibroblasts enter ... | 1999 | 10542195 |
| cloning and molecular characterization of a soluble epoxide hydrolase from aspergillus niger that is related to mammalian microsomal epoxide hydrolase. | aspergillus niger strain lcp521 harbours a highly processive epoxide hydrolase (eh) that is of particular interest for the enantioselective bio-organic synthesis of fine chemicals. in the present work, we report the isolation of the gene and cdna for this eh by use of inverse pcr. the gene is composed of nine exons, the first of which is apparently non-coding. the deduced protein of the a. niger eh shares significant sequence similarity with the mammalian microsomal ehs (meh). in contrast to the ... | 1999 | 10548561 |
| effect of body weight on phosphorus digestibility and efficacy of a microbial phytase in young pigs. | the effect of body weight on p digestibility and on efficacy of supplemental aspergillus niger phytase was studied in two experiments with young growing pigs. excreta were collected quantitatively. all diets contained 2.0 g digestible p per kg dry matter at a maximum and renal p excretion never exceeded 15 mg/d. when dietary p mainly originated from monocalcium-phosphate, both p digestibility and ca net absorption linearly increased by 3.6 and 5.6 percentage units, respectively, when bw increase ... | 1999 | 10548967 |
| comparison of aspergillus niger phytase and trichoderma reesei phytase and acid phosphatase on phytate phosphorus availability in pigs fed on maize-soybean meal or barley-soybean meal diets. | the efficacy of aspergillus niger (aphy) phytase, trichoderma reesei (tphy) phytase and acid phosphatase (tacph) preparations in improving the utilization of phytin-phosphorus in the maize-soybean meal (sbm) or barley-sbm (800:200 g kg-1) diets was studied in two separate digestibility and balance trials with ten growing pigs using 5 x 5 latin square designs. the positive control diet contained a total phosphorus (p) of 6.5 g kg-1, while the negative control as well as the aphy, tphy and tacph s ... | 1999 | 10548973 |
| purification and some properties of an aspergillus niger beta-apiosidase from an enzyme preparation hydrolyzing aroma precursors. | a beta-apiosidase was isolated and purified to electrophoretic homogeneity from an enzyme preparation, klerzyme 200, through ammonium sulfate precipitation, gel filtration chromatography, ion-exchange chromatography, and hplc on ion-exchange and size exclusion columns. the purification of the enzyme was aided by the synthesis of 4-methylumbelliferyl beta-d-apiofuranoside for the specific detection of activity on electrophoresis gels. the molecular mass estimated by sds-page was 120 kda. the opti ... | 1999 | 10552530 |
| hydrolytic properties of a beta-mannosidase purified from aspergillus niger. | a beta-mannosidase was purified to homogeneity from the culture filtrate of aspergillus niger. a specific activity of 500 nkat mg-1 and a 53-fold purification was achieved using ammonium sulfate precipitation, anion-exchange chromatography, and gel filtration. the isolated enzyme has an isoelectric point of 5.0 and appears to be a dimer composed of two 135-kda subunits. it is a glycoprotein and contains 17% n-linked carbohydrate by weight. maximal activity was observed at ph 2.4 5.0 and at 70 de ... | 1999 | 10553664 |
| purification and characterization of an extracellular beta-glucosidase ii with high hydrolysis and transglucosylation activities from aspergillus niger. | an extracellular beta-glucosidase ii (beta-glu ii) has been purified to homogeneity by column chromatography from aspergillus niger ccrc 31494. its molecular mass was estimated to be 360 kda by gel filtration and 120 kda by sds-page. the enzyme has a pi of 4.0 and has optimum activity at ph 4.5 and 60 degrees c. the beta-glu ii was completely inhibited by 5.0 mm fe(2+). methanol (20%, v/v) activated the enzyme activity at 1.8-fold. v(max) values of 10.2 and 464 units/mg were found for p-nitrophe ... | 1998 | 10554258 |
| new pcr method to differentiate species in the aspergillus niger aggregate. | the dna that encodes the 5.8s gene of the ribosomal rna and the two intergenic spacers its1 and its2 of the two proposed type strains of the aspergillus niger aggregate (a. niger and aspergillus tubingensis) have been sequenced. by comparison of sequences we have found that both species could be differentiated by rsai digestion of the pcr products of the mentioned regions. this method could be a useful tool in the identification of strains of the a. niger aggregate, especially in studies that in ... | 1999 | 10556711 |
| a cinnamoyl esterase from aspergillus niger can break plant cell wall cross-links without release of free diferulic acids. | a cinnamoyl esterase, ferulic acid esterase a, from aspergillus niger releases ferulic acid and 5-5- and 8-o-4-dehydrodiferulic acids from plant cell walls. the breakage of one or both ester bonds from dehydrodimer cross-links between plant cell wall polymers is essential for optimal action of carbohydrases on these substrates, but it is not known if cinnamoyl esterases can break these cross-links by cleaving one of the ester linkages which would not release the free dimer. it is difficult to de ... | 1999 | 10561608 |
| antimicrobial activity of selected cyclic dipeptides. | cyclic dipeptides are products of rational drug design, which may exhibit both antimicrobial and antitumor properties. the aim of this study was to investigate both the antimicrobial effects of the cyclic dipeptides cyclo(l-phenylalanyl-l-prolyl), cyclo(l-tyrosyl-l-prolyl), cyclo(l-tryptophanyl-l-prolyl) and cyclo(l-tryptophanyl-l-tryptophanyl) and the effects of these cyclic dipeptides on the gastrointestinal epithelium in vitro. furthermore, a relevant solvent for the possible pharmaceutical a ... | 1999 | 10563376 |
| susceptibility of wheat and aspergillus niger phytases to inactivation by gastrointestinal enzymes. | the activity of wheat and aspergillus niger phytases was determined following preincubation for 60 min at 37 degrees c alone or in the presence of pepsin or pancreatin to examine their ability to survive in the gastrointestinal tract. at ph 3.5 both phytases were stable, but at ph 2.5 wheat phytase rapidly lost activity. following preincubation at ph 3.5 in the presence of 5 mg of pepsin/ml, a. niger phytase retained 95% of its original activity, whereas only 70% of the wheat phytase activity wa ... | 1999 | 10563985 |
| production of substrate for galactose oxidase by depolymerization of an arabinogalactan-peptide from wheat flour. | water extractable arabinogalactan-peptide (we-agp) isolated from white wheat flour was depolymerized enzymatically to liberate substrate for a galactose oxidase from dactylium dendroides. a crude liquid pectolytic preparation from aspergillus niger (p70) displayed activities capable of converting we-agp into a substrate for galactose oxidase. the most favorable substrate was observed when we-agp was not fully depolymerized into galactose and arabinose. alpha-l-arabinofuranosidase b from a. niger ... | 1999 | 10564003 |
| glucoamylase overexpression and secretion in aspergillus niger: analysis of glycosylation. | we have studied the effects of overexpression and secretion of a homologous model glycoprotein, glucoamylase (gam-1), on glycosylation in a single gene copy wild-type parent and multiple gene copy transformants of aspergillus niger. in batch culture the b36 strain, which possess 80 additional copies of the gam glaa gene, secreted about 5-8-fold more protein and gam-1 than the parent strain (n402). a comparison of the glycosylation of gam-1 secreted by the parent strain with that secreted by the ... | 1999 | 10564772 |
| a comparative study of mono mac 6 cells, isolated mononuclear cells and limulus amoebocyte lysate assay in pyrogen testing. | pyrogen induced secretion of interleukin 6 (il-6) in mono mac 6 (mm6) cells was measured. the ability of the mm6 cell culture to detect pyrogens was compared to the limulus amoebocyte lysate (lal) test and isolated mononuclear cells (mnc). the detection limit of mm6 for lipopolysaccharide (lps) and staphylococcus aureus was comparable to that of mnc. aspergillus niger and candida albicans induced il-6 in isolated mnc, but not in mm6. the detection limit for salmonella typhimurium in the mm6 assa ... | 1999 | 10564840 |
| characterization of the n-linked glycosylation site of recombinant pectate lyase. | recombinant pectate lyase from aspergillus niger was overexpressed in aspergillus nidulans. the two recombinant proteins produced differed in molecular mass by 1200 da, which suggested that the larger molecular weight protein was glycosylated. the deduced amino acid sequence was searched for potential n-linked glycosylation sites, and one potential site was identified at residue 64. the proteins were analyzed for their ability to bind various lectins as an assay for the presence of carbohydrates ... | 1999 | 10567938 |
| oxalate-producing pulmonary aspergillosis in an alpaca. | an aging lactating alpaca was presented in sternal recumbency. although bright and alert, she did not respond to symptomatic treatment and was euthanized 5 weeks after initial presentation. gross postmortem examination revealed purulent material in the pulmonary airways. histologic examination of the lungs revealed an extensive pyogranulomatous pneumonia with bronchiectasis. there were abundant fungal hyphae and high numbers of associated oxalate crystals, which were presumed to have been produc ... | 1999 | 10568451 |
| biotransformation of n-acetylphenothiazine by fungi. | cultures of the fungi aspergillus niger, cunninghamella verticillata, and penicillium simplicissimum, grown in a sucrose/peptone medium, transformed n-acetylphenothiazine to n-acetylphenothiazine sulfoxide (from 13% to 28% of the total) and phenothiazine sulfoxide (from 5% to 27%). phenothiazin-3-one (4%) and phenothiazine n-glucoside (4%) were also produced by c. verticillata. the probable intermediate, phenothiazine, was detected only in cultures of p. simplicissimum (6%). | 1999 | 10570803 |
| spectroscopic characterization of carbon monoxide complexes generated for copper/topa quinone-containing amine oxidases. | carbon monoxide complexes have been generated for copper/topa quinone (tpq)-containing amine oxidases from arthrobactor globiformis (agao) and aspergillus niger (ao-i) and characterized by various spectroscopic measurements. addition of co to agao anaerobically reduced with its substrate 2-phenylethylamine led to a slight increase of absorption bands at 440 and 470 nm derived from the semiquinone form (tpq(sq)) of the tpq cofactor, concomitantly giving rise to new co-related absorption bands at ... | 1999 | 10571999 |
| aspergillosis with calcification of the maxillary sinus. | | 1999 | 10577765 |
| genetic improvement of aspergillus carbonarius for pectinase overproduction during solid state growth. | low pectinase production by aspergillus carbonarius growing on wheat bran solid substrate was found to be due to reduced colonizational ability of the fungus. since a. niger showed higher growth rates on wheat bran, strain improvement to obtain higher pectinase production in solid state was carried out by inter-specific fusion of protoplasts of a. carbonarius and a. niger. one of the mutants selected for higher activities of alpha-glucosidase showed improved growth rates on wheat bran solid subs ... | 2000 | 10581444 |
| new metal-binding ethyldiamino- and dicarboxy-products from aspergillus niger industrial wastes. | the metal-binding ability of aspergillus niger mycelial waste was improved by chemical modification. the latter was performed by introducing additional carboxy groups using oxidation methods or the introduction of the ethyldiamino group first by chlorination of a. niger using mesyl chloride and subsequent reaction of the product with ethylene diamine. metal binding abilities of the products for cd2+, co2+, ni2+ and zn2+ were determined according to the langmuir model, whereby pkd*-values of 3.88 ... | 1999 | 10581688 |
| characterization and analysis of antibiotic activity of some aquatic actinomycetes. | nine different isolates of aquatic actinomycetes identified as streptomyces spp. were studied for their morphological and cultural characteristics. one of these isolates (c4-s, streptomyces violaceusniger) was extensively studied for its inhibitory effect against a wide range of gram-positive, gram-negative bacteria, mycobacterium vaccae atcc 29678, candida albicans and several food associated filamentous fungi and yeasts. most of these were characterized by flexous sporophore morphology and the ... | 1999 | 10581729 |