| uptake and export of citric acid by aspergillus niger is reciprocally regulated by manganese ions. | the uptake as well as the export of citric acid by aspergillus niger occur by active, deltaph-driven, h(+)-symport dependent systems. they are inhibited by nonmetabolizable tricarboxylic acid analogues and phthalic acid, and by several other mono-, di- and tribasic organic acids. however, citrate export could only be demonstrated in a mycelium cultivated under manganese-deficient growth conditions, whereas the uptake of citrate from the medium was only detectable upon precultivation of a. niger ... | 1997 | 9218559 |
| structural and dynamical properties of a denatured protein. heteronuclear 3d nmr experiments and theoretical simulations of lysozyme in 8 m urea. | oxidized and reduced hen lysozyme denatured in 8 m urea at low ph have been studied in detail by nmr methods. 15n correlated noesy and tocsy experiments have provided near complete sequential assignment for both 1h and 15n resonances. over 900 noes, including 130 (i, i + 2) and 23 (i, i + 3) noes, could be identified by analysis of the noesy spectra of the denatured states, and 3j(hn, halpha) coupling constants and 15n relaxation rates have been measured. the coupling constant and noe data were ... | 1997 | 9220986 |
| carbon repression in aspergilli. | many microorganisms prefer easily metabolizable carbon sources over alternative, less readily metabolized carbon sources. one of the mechanisms to achieve this is repression of the synthesis of enzymes related to catabolism of the alternative carbon sources, i.e. carbon repression. it is now clear that in aspergillus nidulans and aspergillus niger the repressor protein crea plays a major role in carbon repression. crea inhibits transcription of many target genes by binding to specific sequences ... | 1997 | 9228741 |
| secretion of active recombinant phytase from soybean cell-suspension cultures. | phytase, an enzyme that degrades the phosphorus storage compound phytate, has the potential to enhance phosphorus availability in animal diets when engineered into soybean (glycine max) seeds. the phytase gene from aspergillus niger was inserted into soybean transformation plasmids under control of constitutive and seed-specific promoters, with and without a plant signal sequence. suspension cultures were used to confirm phytase expression in soybean cells. phytase mrna was observed in cultures ... | 1997 | 9232886 |
| aspergillus as a host for heterologous protein production: the problem of proteases. | homologous and heterologous protein production by filamentous fungi is often limited by the expression of proteases at high levels. by eliminating specific protease activities, protein production in aspergillus niger can be improved considerably. both classical mutagenesis and gene disruption techniques have yielded strains with reduced protease expression. combinations of these mutations and disruptions result in a further reduction of protease activity. the coupling of efficient promoters to t ... | 1997 | 9237405 |
| [aspergillus niger osteitis of the middle ear in a patient with hiv infection]. | | 1997 | 9246102 |
| analysis of conductance responses during depolymerization of pectate by soft rot erwinia spp. and other pectolytic bacteria isolated from potato tubers. | different bacteria isolated from potato tubers were screened for their pectolytic properties by examining pitting in polypectate agar, recording conductance responses in polypectate medium and performing potato tuber soft rot tests. for bacteria found positive in conductimetry, the role of polygalacturonase (pg) and pectate lyase (pl) in the generation of conductance changes in a polygalacturonic acid (pga) medium was further analysed using enzyme activity staining after gel electrophoresis and ... | 1997 | 9246767 |
| preliminary studies on tannin degradation by aspergillus niger van tieghem mtcc 2425. | a tannin-degrading strain of aspergillus niger van tieghem was grown at ph 5.0 and 30 degrees c in a defined medium where tannins were the sole source of carbon and energy. the fungus had variable growth in tannic acid- and quebracho tannin-medium and could tolerate these tannins even up to 150 g-1 without showing any growth inhibition. | 1997 | 9248075 |
| [significance of aspergillus fumigatus rdna detected by polymerase chain reaction in diagnosis of pulmonary aspergillosis]. | we have studied the clinical significance of aspergillus fumigatus rdna detected by polymerase chain reaction (pcr) for diagnosing aspergillosis. for this purpose, a specific and sensitive pcr assay was developed to amplify the 26s rdna/intergenic spacer region of a. fumigatus. control experiments showed that the set of primers used was capable of amplifying a. fumigatus dna specifically and that the dna amount of detection limit was 1 pg. eighteen samples from 13 patients with aspergillosis and ... | 1997 | 9248266 |
| a catalytic amino acid and primary structure of active site in aspergillus niger alpha-glucosidase. | the catalytic amino acid residue of aspergillus niger alpha-glucosidase (angase) was identified by modification with conduritol b epoxide (cbe), a mechanism-based irreversible inactivator. the inactivation by cbe followed pseudo-first order kinetics. the interaction of cbe and angase conformed to a model with a reversible enzyme-inhibitor complex formed before covalent inactivation. a competitive inhibitor, tris, decreased the inactivation rate. the incorporation of one mole of cbe per mole of a ... | 1997 | 9255970 |
| isolation and characterisation of a novel stress-inducible pdi-family gene from aspergillus niger. | current strategies to improve the secretion of heterologous proteins in aspergillus niger include the manipulation of chaperones and foldases specific to the endoplasmic reticulum (er). a family of er-specific proteins which share active-site homology wit protein disulfide isomerase (pdi) has been identified from other systems, many of which are inducible by agents which cause malfolding of proteins in the er. here we report identification of tiga from aspergillus niger and erp38 from neurospora ... | 1997 | 9256071 |
| analysis of the role of the spitzenkörper in fungal morphogenesis by computer simulation of apical branching in aspergillus niger. | high-resolution video microscopy, image analysis, and computer simulation were used to study the role of the spitzenkörper (spk) in apical branching of ramosa-1, a temperature-sensitive mutant of aspergillus niger. a shift to the restrictive temperature led to a cytoplasmic contraction that destabilized the spk, causing its disappearance. after a short transition period, new spk appeared where the two incipient apical branches emerged. changes in cell shape, growth rate, and spk position were re ... | 1997 | 9256441 |
| the efficacy of aspergillus niger phytase in rendering phytate phosphorus available for absorption in pigs is influenced by pig physiological status. | we performed an experiment with 112 piglets, 32 growing-finishing pigs, and 12 sows during pregnancy and lactation to test the hypotheses that apparent total tract digestibilities of p and ca as well as the efficacy of aspergillus niger phytase in rendering phytate p available in pigs depend on pig physiological status. all pigs were fed diets with identical feedstuff composition either without or with added microbial phytase (natuphos, 500 ftu/kg diet). the diets contained 6.2 g ca, 4.8 g total ... | 1997 | 9263060 |
| the effects of sow parity on digestibility of proximate components and minerals during lactation as influenced by diet and microbial phytase supplementation. | ninety-six (finnish landrace x dutch landrace) reproductive sows were used at parities 1, 3, 5, and 7 + 8 from d 107 of gestation to d 21 of lactation to investigate the effects of diet and parity on apparent total tract digestibility (attd). animals were randomly assigned to one of four dietary treatments. dietary treatments were 1) a p-deficient (1.1 g digestible p [dp]/kg) dutch semipractical diet; 2) diet 1 supplemented with 400 ftu aspergillus niger phytase per kilogram of diet (1.7 g dp/kg ... | 1997 | 9263062 |
| disruption of three acid proteases in aspergillus niger--effects on protease spectrum, intracellular proteolysis, and degradation of target proteins. | three acid protease genes encoding two extracellular proteases (pepa and pepb) and one intracellular protease (pepe) were disrupted in aspergillus niger. northern-blot analysis showed the absence of wild-type protease mrnas in the disruptants while western-blot analysis proved the absence of the encoded proteases. characterization of the residual proteolytic spectra in the disruptants indicated that the extracellular protease activity was reduced to 16% and 94% for the delta pepa and the delta p ... | 1997 | 9266703 |
| isolation and properties of an atp transporter from a strain of aspergillus niger. | a purified atp transporter from aspergillus niger did not show release or uptake for any of the nucleotides (adp or utp) except atp. the release and uptake did not result from non-specific binding, but appeared to be concentration-dependent processes. atp was shown by a double-isotopic technique to be transported across membrane vesicles without degradation. the atp-transport protein was purified to near homogeneity from the membrane vesicles of a strain of a. niger and its apparent mr was appro ... | 1997 | 9266712 |
| cell wall analysis in aspergillus niger strains characterized by different tolerance to toxic compounds of beet molasses. | aspergillus niger strains, sensitive or resistant to toxic compounds of beet molasses, were the object of the present studies. between the studied strains differences existed in the cell wall dry mass and wall components content, chitin synthesis, activity of enzymes involved in cell wall synthesis, and in the wall ultrastructure. higher content of proteins and lipids but lower of glucan and chitin; less or lack of fibrillar components, thinner cell wall as well as lower level of glucanase and c ... | 1997 | 9271845 |
| immunoreactivity of a 38-kilodalton penicillium marneffei antigen with human immunodeficiency virus-positive sera. | penicillium marneffei produced and secreted a 38-kda antigen that appeared to be specific for this dimorphic fungus. this component could not be detected in antigenic extracts of histoplasma capsulatum, cryptococcus neoformans, aspergillus niger, aspergillus fumigatus, aspergillus flavus, aspergillus terreus, candida albicans, and two other species of penicillium by immunoblot analysis against the sera from patients with culture-confirmed penicilliosis marneffei. antibody reactive with this anti ... | 1997 | 9276391 |
| identification of the glycosylation site and glycan structures of recombinant endopolygalacturonase ii by mass spectrometry. | a series of mass spectrometric experiments was performed to characterize the carbohydrate chains attached to endopolygalacturonase ii (epg-ii) overexpressed in aspergillus niger. first, an aliquot of trypsin-digested epg-ii was analyzed by capillary high-performance liquid chromatography (hplc) coupled with electrospray ionization (esi) mass spectrometry (hplc/ms). the esi mass spectrometer was operated in the tandem mass spectrometric (ms/ms) mode and utilized precursor ion scanning of the hexn ... | 1997 | 9276972 |
| serum aspergillus galactomannan antigen testing by sandwich elisa: practical use in neutropenic patients. | the double sandwich elisa detecting aspergillus galactomannan (gm) was prospectively evaluated for the diagnosis of invasive aspergillosis (ia) in 50 haematological patients at risk for ia. serum samples were collected once weekly as long as the risk factors persisted. six patients had proven or probable ia (3 a. fumigatus, 1 a. flavus, 1 a. niger, 1 a. ustus) and the gm titres were parallel to the clinical evolution of ia. six of nine patients with suspected ia had at least two consecutive seru ... | 1997 | 9279718 |
| chemical and thermal stability of ferulic acid esterase-iii from aspergillus niger. | the stability of ferulic acid esterase iii (fae-iii) from aspergillus niger was examined using chemical and thermal denaturation. thermal denaturation was irreversible and the loss of activity was dependent on ph. at 60 degrees c and ph 6.0, the rate constant of unfolding was 0.76 10(-3)/s, and the change in free energy of irreversible inactivation, deltag*, was 101.9 kj/mol. sinapic acid, a product of the reaction of methyl sinapate with fae-iii, reduced the rate of unfolding (0.66 10(-3)/s at ... | 1997 | 9283031 |
| cloning heterologous genes: problems and approaches. | model fungi such as neurospora crassa, aspergillus niger, and saccharomyces cerevisiae have provided a wealth of genetic information and are currently the object of cooperative genome sequencing projects. many agriculturally and medically economic important pathogenic fungi, however, are less well characterized, which makes it difficult to study their genes and gene products. gene sequences from model fungi offer a unique opportunity to clone cognate genes from pathogenic counterparts. in this r ... | 1997 | 9290241 |
| synthesis and antifungal activity of some imidazo, pyrazino and v-triazoloquinoxalines. | the reaction of 6,7-diamino-1,4-diethyl-11-quinoxaline-1 h,4h-2,3-dione (1) with aliphatic and aromatic carboxylic acids in the presence and absence of an acid catalyst affords 2-alkyl- and 2-aryl-5,8-diethyl-imidazo[4,5-g]quinoxaline-5 h,8 h-6,7-diones 2a-1. cyclization of 1 with carbon disulphide in basic medium yields 2-mercapto-5,8-diethyl-imidazo[4,5-g]-quinoxaline-5 h,8 h-6,7-dione (4) which on reactions with methyl iodide and substituted benzyl halides give the s-substituted derivatives 5 ... | 1997 | 9292915 |
| black corneal ulcer. | to discuss the etiology of an unusual finding of black color in a corneal ulcer. | 1997 | 9294695 |
| solubilisation of some naturally occurring metal-bearing minerals, limescale and lead phosphate by aspergillus niger. | the ability of the soil fungus aspergillus niger to tolerate and solubilise seven naturally occurring metal-bearing minerals, limescale and lead phosphate was investigated. a. niger was able to solubilise four of the test insoluble compounds when incorporated into solid medium: cuprite (cuo2), galena (pbs), rhodochrosite (mn(co3)x) and limescale (caco3). a. niger was able to grow on all concentrations of all the test compounds, whether solubilisation occurred or not, with no reduction in growth ... | 1997 | 9297818 |
| polygalacturonase-inhibiting proteins (pgips) with different specificities are expressed in phaseolus vulgaris. | the pgip-1 gene of phaseolus vulgaris, encoding a polygalacturonase-inhibiting protein (pgip), pgip-1 (p. toubart, a. desiderio, g. salvi, f. cervone, l. daroda, g. de lorenzo, c. bergmann, a. g. darvill, and p. albersheim, plant j. 2:367-373, 1992), was expressed under control of the cauliflower mosaic virus 35s promoter in tomato plants via agrobacterium tumefaciens-mediated transformation. transgenic tomato plants with different expression levels of pgip-1 were used in infection experiments w ... | 1997 | 9304859 |
| isolation of aspergillus niger crea mutants and effects of the mutations on expression of arabinases and l-arabinose catabolic enzymes. | aspergillus niger mutants relieved of carbon repression were isolated from an area parental strain by selection of colonies that exhibited improved growth on a combination of 4-aminobutanoic acid (gaba) and d-glucose. in addition to derepression of the utilization of gaba as a nitrogen source in the presence of d-glucose, three of the four mutants also showed derepression of l-alanine and l-proline utilization. transformation of the mutants with the a. niger crea gene, encoding the repressor pro ... | 1997 | 9308182 |
| secretion of two beta-fructofuranosidases by aspergillus niger growing in sucrose. | aspergillus niger is induced to secrete two invertases, named suc 1 and suc 2, when grown on a minimal medium containing sucrose. although, both have been classified as beta-d-fructofuranoside fructohydrolases, suc 2 also possesses inulin hydrolytic activity (sucrose/inulin activity ratio of 4). these activities have been separated from each other and almost completely purified by anion-exchange, lectin affinity chromatography, and chromatofocusing. suc 1 appeared as a single glycoprotein band o ... | 1997 | 9308892 |
| production of the homologous pectin lyase b protein in six genetically defined protease-deficient aspergillus niger mutant strains. | an expression cassette has been transformed into six protease-deficient (prt) mutant strains of aspergillus niger. transformants were tested for improved production of the proteolytically susceptible pelb tester protein. in four complementation groups (prta, b, d and f) distinct improvement of pelb yield was observed. these in vivo experiments in single prt mutants confirmed earlier in vitro pelb degradation data and demonstrated how the use of protease-deficient mutants can significantly improv ... | 1997 | 9309173 |
| methyl phenylalkanoates as substrates to probe the active sites of esterases. | we have used methyl esters of phenylalkanoic acids to probe the active site of two esterases (fae-iii and cinnae) from aspergillus niger. only methyl 4-hydroxy-3-methoxycinnamate and 4-hydroxy-3-methoxyphenylpropionate out of 19 substrates tested were significant substrates for both enzymes (k(cat) values about 10(2) s(-1) and 10(3) s(-1), respectively). lengthening or shortening the aliphatic side chain while maintaining the same aromatic substitutions completely abolished activity for both enz ... | 1997 | 9310385 |
| mycoflora of paddy and milled rice produced in the region of northeastern argentina and southern paraguay. | thirty samples of paddy rice and twenty-five of milled rice were obtained from processing centers located in two northern provinces of argentina and one southern province of paraguay. contaminating fungi were enumerated by direct plating on dichloran rose bengal chloramphenicol agar and oxytetracycline glucose yeast extract agar before and after surface disinfection. all fungi were isolated and identified to the genus level and percentage infection of samples calculated. those belonging to the g ... | 1997 | 9310860 |
| diagnostic value of conidia associated with pulmonary oxalosis: evidence of an aspergillus niger infection. | bronchoalveolar lavage (bal) material is commonly received in cytopathology for the exclusion of microorganisms. when crystalline material suggestive of calcium oxalate is present in the specimen, a search for fungal elements should be undertaken. aspergillus niger is the hyaline mold associated with the presence of oxalate crystals. commonly fragments of hyphae and occasionally entire conidiophores may be present in bal specimens from patients with aspergillosis. we report a case of a patient w ... | 1997 | 9316786 |
| a model for the combined effects of temperature and salt concentration on growth rate of food spoilage molds. | we modeled mold growth on a solid culture medium at various temperatures and nacl concentrations by using five common food spoilage molds (penicillium roqueforti, trichoderma harzianum, paecilomyces variotii, aspergillus niger, and emericella nidulans). for the description of the growth rate (expressed as the increase in colony diameter per unit of time) as a function of temperature and nacl concentration, a six-parameter model has been developed. the model combines either the rosso-type or the ... | 1997 | 9327540 |
| overexpression of the aspergillus niger ph 2.5 acid phosphatase gene in a heterologous host trichoderma reesei. | an aspergillus gene coding for a ph 2.5 acid phosphatase enzyme was successfully overexpressed in trichoderma reesei under the strong main cellobiohydrolase i (cbh 1) promoter. the best transformants produced up to 240 times more of the acid phosphatase than the aspergillus strain from which the phosphatase gene was originally isolated. the recombinant enzyme was effectively secreted into the culture medium both by its own and the cbh 1 secretion signal. the heterologous ph 2.5 acid phosphatase ... | 1997 | 9335175 |
| immobilization of beta-fructofuranosidases from aspergillus on methacrylamide-based polymeric beads for production of fructooligosaccharides. | beta-fructofuranosidases from aspergillus niger atcc 20611 and aspergillus japonicus tit-kj1 were purified and immobilized covalently onto methacrylamide-based polymeric beads. the porous, oxriane-containing support was reactive and could bind enzymes in a buffered solution at room temperature with a density up to 0.4 mg of protein g-1 of support with 100% immobilized yield. neither the optimum temperature for the highest enzymatic activities nor the batch reaction pattern for fructooligosacchar ... | 1997 | 9336977 |
| a novel acid phosphatase from aspergillus niger ku-8 that specifically hydrolyzes c-6 phosphate groups of phosphoryl oligosaccharides. | we had analyzed the detailed structures of the phosphoryl oligosaccharide-1 (po-1) fraction that was the main component of phosphoryl oligosaccharides (pos) prepared from a potato starch hydrolysate. po-1 fraction was made up of 3-phosphoryl oligosaccharides and 6-phosphoryl oligosaccharides. aspergillus niger strain ku-8 produced two types of intracellular acid phosphatase (ec 3.1.3.2, acpase); acpase i and ii. acpase ii preferentially dephosphorylated 6-phosphoryl oligosaccharides rather than ... | 1997 | 9339554 |
| biodeterioration potentials of fungal isolates from vegetable oils. | the biodeterioration potentials of fungi isolated from vegetable oils were investigated. growth of pure cultures of some mould species (aspergillus flavus, aspergillus niger, aspergillus sp., penicillium sp. and fusarium sp.) and a mixed yeast culture (saccharomyces sp., candida sp. and hansenula sp.) were monitored using six vegetable oils as substrates. mould growth resulted in an increase in mycelial dry weight (g/100 ml) of the cultures in all the oils. yeast growth in the oils caused decrea ... | 1997 | 9349441 |
| structural characterization of the gene and corresponding cdna for the cytochrome p450rm from rhodotorula minuta which catalyzes formation of isobutene and 4-hydroxylation of benzoate. | cytochrome p450rm was previously isolated from the basidiomycete yeast rhodotorula minuta as a bifunctional enzyme with isobutene-forming and benzoate 4-hydroxylase activities. we cloned the gene and corresponding cdna for p450rm in order to characterize the enzyme in the context of fungal phylogeny and physiology. from the cdna sequence, p450rm was deduced to have 527 amino acids with a calculated molecular weight of 59136. p450rm shared 48% amino acid sequence identity with cyp53a1 from asperg ... | 1997 | 9349702 |
| cloning of the phytases from emericella nidulans and the thermophilic fungus talaromyces thermophilus. | phytases (ec 3.1.3.8) belong to the family of histidine acid phosphatases. we have cloned the phytases of the fungi emericella nidulans and talaromyces thermophilus. the putative enzyme encoded by the e. nidulans sequence consists of 463 amino acids and has a mr of 51785. the protein deduced from the t. thermophilus sequence consists of 466 amino acids corresponding to a mr of 51450. both predicted amino acid sequences exhibited high identity (48% to 67%) to known phytases. this high level of id ... | 1997 | 9349716 |
| extraction of lithium from spodumene by bioleaching. | the recovery of lithium from spodumene (6.9% li2o) by bioleaching was investigated. this process was carried out using heterotrophic micro-organisms previously isolated from the mineral. penicillium purpurogenum, aspergillus niger and rhodotorula rubra were assayed separately. two different media were used for bioleaching; one of them (m2 medium) was highly limited in mg2+, fe2+ and k+. the assays were carried out in 500 ml erlenmeyer flasks with 1 g of ground mineral at 50-80 mesh and 150 ml of ... | 1997 | 9351258 |
| action patterns and mapping of the substrate-binding regions of endo-(1-->5)-alpha-l-arabinanases from aspergillus niger and aspergillus aculeatus. | the substrate binding sites of endo-(1-->5)-alpha-l-arabinanases (ec 3.2.1.99) from aspergillus niger and aspergillus aculeatus were investigated using reduced and regular (1-->5)-alpha-l-arabino-oligosaccharides and high performance anion exchange chromatographic analysis. calculation of bond cleavage frequencies and kcat/k(m) parameters for these substrates enabled the determination of the number of arabinofuranosyl binding subsites and the estimation of the binding affinities of each subsite. ... | 1997 | 9352635 |
| exogenous aspergillus niger endophthalmitis in a patient with a filtering bleb. | | 1997 | 9355201 |
| microbial transformation of sclareolide. | the microbial transformation of sclareolide (1) by curvularia lunata afforded five oxidized metabolites identified as 3-ketosclareolide (2), 1 beta-hydroxysclareolide (3), 3 beta-hydroxysclareolide (4), 1 alpha,3 beta-dihydroxysclareolide (5), and 1 beta, 3 beta-dihydroxysclareolide (6). fermentations of 1 with aspergillus niger also produced metabolites 2-6. metabolites 2-5 were obtained by fermention with gibberella fujikuroii, while fermentation with fusarium lini afforded metabolites 4 and 5 ... | 1997 | 9358647 |
| effects of elevated dissolved co2 levels on batch and continuous cultures of aspergillus niger a60: an evaluation of experimental methods. | the effects of elevated levels of dissolved carbon dioxide (dco2), produced by gassing with co2-enriched gas mixtures, upon an industrial strain of aspergillus niger (strain a60) producing citrate and gluconate were quantitatively assessed. particular attention was paid to the reliability and accuracy of the steam-sterilizable dco2 probe, especially in the presence of high concentrations of potentially interfering acidic species. the response of the organism to elevated dco2 levels was assessed ... | 1997 | 9361401 |
| glucoamylase structural, functional, and evolutionary relationships. | to correlate structural features with glucoamylase properties, a structure-based multisequence alignment was constructed using information from catalytic and starch-binding domain models. the catalytic domain is composed of three hydrophobic folding units, the most labile and least hydrophobic of them being missing in the most stable glucoamylase. the role of o-glycosylation in stabilizing the most hydrophobic folding unit, the only one where thermostabilizing mutations with unchanged activity h ... | 1997 | 9365988 |
| the er chaperone encoding bipa gene of black aspergilli is induced by heat shock and unfolded proteins. | we describe the cloning and characterisation of the bip gene homologues of the filamentous fungi aspergillus niger and aspergillus awamori. the bip genes of these black aspergilli encode an identical protein of 672 amino acids, which has a high homology with the bip protein from saccharomyces cerevisiae and contains a putative signal sequence of 38 amino acids. the dna sequences of the aspergillus bip genes diverge in particular in the three intronic sequences and the 5'- and 3'- noncoding regio ... | 1997 | 9370263 |
| isolation of the glucose oxidase gene from talaromyces flavus and characterisation of its role in the biocontrol of verticillium dahliae. | the glucose oxidase gene from the biocontrol fungus talaromyces flavus has been isolated and shown to be only 64% identical at the amino-acid sequence level to the similar enzyme from aspergillus niger. a transformation system has been developed for both t. flavus and the related t. macrosporus and has been used to create talaromyces spp. which either over-express or are deficient in glucose oxidase. in vitro inhibition experiments on verticillium dahliae using culture filtrates from these trans ... | 1997 | 9371889 |
| brewer's asthma due to malt contamination. | we describe a case of a 28 year old brewery worker who developed asthma whilst grinding malt. lung function measurements demonstrated deterioration and improvement in lung function associated with work and absence from work. inhalation challenge with ground malt from the brewery was positive but with ground malt from another source was negative suggesting a contaminant of the malt was responsible. culture of the brewery malt showed heavy contamination with aspergillus niger, but a. niger skin te ... | 1997 | 9374067 |
| the ability of soil-borne fungi to degrade organophosphonate carbon-to-phosphorus bonds. | the ability of a wide variety of soil-borne fungal strains to degrade four structurally different compounds containing p-c bonds, namely the naturally occurring amino acid ciliatine, the popular herbicide glyphosate, phosphonoacetic acid and 2-amino-3-phosphonopropionic acid, was studied in order to show that soil fungi may play an important role in the biodegradation of organophosphonates. most of the strains appeared to utilize ciliatine as the sole source of phosphorus for growth. only a limi ... | 1997 | 9390463 |
| isolation and analysis of functional homologues of the secretion-related sar1 gene of saccharomyces cerevisiae from aspergillus niger and trichoderma reesei. | the aspergillus niger and trichoderma reesei genes encoding the functional homologues of the small gtp-binding protein sar1p, which is involved in the secretion pathway in saccharomyces cerevisiae, have been cloned and characterised. the a. niger gene (sara) contains five introns, whereas the t. reesei gene (sar1) has only four. in both cases the first intron is at the same position as the single s. cerevisiae sar1 intron. the encoded proteins show 70-80% identity to the sar1 protein. complement ... | 1997 | 9393442 |
| organotin complexes with pyrrole-2-carboxaldehyde monoacylhydrazones. synthesis, spectroscopic properties, antimicrobial activity, and genotoxicity. | a series of organotin complexes with pyrrole-2-carboxaldehyde 2-hydroxybenzoylhydrazone (h3mfps) and pyrrole-2-carboxaldehyde 2-picolinoylhydrazone (h2mfpp) was investigated. the ir, 1h, and 119sn nuclear magnetic resonance spectroscopic characterization of all the compounds is reported and discussed in connection with the ligand behaviour of the hydrazone and the structure of the organotin complex. complexes exhibit antibacterial properties higher than those of the corresponding ligands but the ... | 1997 | 9397578 |
| comparison of different methods for extraction of dna of fungal pathogens from cultures and blood. | five commercially available extraction kits and an in-house dna extraction method for the release of dna from candida albicans and aspergillus niger cells were assessed for sensitivity, purity, duration, and cost. all commercially available kits helped to shorten the duration of dna extraction. however, the sensitivity varied from 1 to 1,000 fungal cells/ml and costs varied from $0.10 to 2.30. the qiamp tissue kit was the commercially available assay that yielded the same sensitivity and purity ... | 1997 | 9399543 |
| the faea genes from aspergillus niger and aspergillus tubingensis encode ferulic acid esterases involved in degradation of complex cell wall polysaccharides. | we report the cloning and characterization of a gene encoding a ferulic acid esterase, faea, from aspergillus niger and aspergillus tubingensis. the a. niger and a. tubingensis genes have a high degree of sequence identity and contain one conserved intron. the gene product, faea, was overexpressed in wild-type a. tubingensis and a protease-deficient a. niger mutant. overexpression of both genes in wild-type a. tubingensis and an a. niger protease-deficient mutant showed that the a. tubingensis g ... | 1997 | 9406381 |
| antimicrobial screening of selected medicinal plants from india. | from the indian traditional medicines 78 plants were selected on the basis of their use in the treatment of infectious diseases. different concentrations of 80% ethanol extracts were tested, using the agar dilution method, against four bacteria: bacillus subtilis, staphylococcus aureus, escherichia coli and pseudomonas aeruginosa and, using the agar-well diffusion method, against two fungi: candida albicans and aspergillus niger. in the lowest tested concentration of 1.6 mg/ml, 10% of the plant ... | 1997 | 9406894 |
| kinetics of simultaneous saccharification and lactic acid fermentation processes. | after pretreatment of corn cob by dilute acid, the lignocellulosic residue was used as raw materials for the simultaneous saccharification and lactic acid fermentation (sslf). because of the same optimal temperature and ph requirement as well as the anaerobic condition, the lactic acid fermentation is perfectly compatible with enzymatic hydrolysis of cellulosic materials. in the sslf processes, the final concentration of lactic acid reached 33.97 g/l with a conversion ratio of 79% based on the c ... | 1997 | 9413134 |
| identification and characterization of a novel arabinoxylanase from wheat flour. | an endogenous wheat (triticum aestivum) flour endoxylanase was purified to homogeneity from a crude wheat flour extract by ammonium sulfate precipitation and cation-exchange chromatography. the 30-kd protein had an isoelectric point of 9.3 or higher. a sequence of 19 amino acids at the nh2 terminus showed 84.2% identity with an internal sequence of 15-kd grain-softness protein, friabilin. high-performance anion-exchange chromatography and gel-permeation analysis of the hydrolysis products indica ... | 1997 | 9414565 |
| endoglucanase production by paper-degrading mycoflora. | fourteen fungal species, namely aspergillus flavus, a. fumigatus, a. niger, a. ustus, penicillium islandicum, p. wortmannii, memnoniella echinata, cladosporium herbarum, stachybotrys atra, chaetomium globosum, fusarium oxysporum, torula herbarum, alternaria alternata and curvularia uncinata were isolated from different grades of paper. they differ in their distribution on various kinds of paper and also in relative occurrence. while seasonal influence on mycoflora was observed, most of the mould ... | 1997 | 9418063 |
| expression of the cefg gene is limiting for cephalosporin biosynthesis in acremonium chrysogenum. | the conversion of deacetylcephalosporin c to cephalosporin c is inefficient in most acremonium chrysogenum strains. the cefg gene, which encodes deacetylcephalosporin c acetyltransferase, is expressed very poorly in a. chrysogenum as compared to other genes of the cephalosporin pathway. introduction of additional copies of the cefg gene with its native promoter (in two different constructions with upstream regions of 1056 bp and 538 bp respectively) did not produce a significant increase of the ... | 1997 | 9421924 |
| purification and characterization of a thermostable and highly specific beta-n-acetyl-d-glucosaminidase from aspergillus niger 419. | after a 10.5-fold purification, beta-n-acetyl-d-glucosaminidase (ec 3.2.1.52) produced by aspergillus niger 419, showed the following main characteristics: maximum activity at 65 degrees c, ph 4.5; k(m) and kcat using p-nitrophenyl-n-acetyl-beta-d-glucosaminide as substrate, 0.2 mm and 0.93 x 10(4) min-1, respectively; ea, 30.5 kj/mol; molecular mass, 131,000 da; pi 4.4. the activity after heating for 15 min at 70, 75 and 80 degrees c was 70, 28 and 13% of that found at 65 degrees c, respectivel ... | 1997 | 9428156 |
| effect of spumol k on cell wall of aspergillus niger strains characterized by different tolerance to toxic compounds of beet molasses. | cell walls in the mycelium of aspergillus niger strains sensitive or resistant to toxic molasses compounds growing in the presence of spumol k were the object of the present studies. although the inhibitory effect of spumol k on the cell wall was noticed in studied mycelia the sensitive strains reacted more strongly. in sensitive strains in spumol k presence lower content of cell wall was accomplished by higher amount of proteins but lower of lipids as well as structural polymers i.e. of glucans ... | 1997 | 9429292 |
| purification and some properties of beta-glucosidase from aspergillus niger ibt-90. | beta-glucosidase (ec 3.2.1.21) was isolated from the culture filtrate of aspergillus niger ibt-90. the crude extracellular enzyme preparation was fractionated by six step purification procedure, (nh4)2so4 precipitation, gel filtration on bio-gel p-10 and p-100, an ion-exchange chromatography on deae bio-gel a, yielding beta-glucosidase with an isoelectric point at ph 4.05. the enzyme was found to be a dimer with an apparent molecular weight of approximately 200 kda as determined by size exclusio ... | 1997 | 9429294 |
| hybridization dominance of kinetics in recombinant ath-1376 obtained via protoplast fusion between aspergillus niger and trichoderma reesei. | comparisons of the kinetics of mycelium growth, cellulase biosynthesis, and the degradation of filter paper to accumulate reducing-sugar by the filtrates of cultures were carried out among the recombinant strain ath-1376 and its two parents, aspergillus niger ams11 and trichoderma reesei qm9414. the results showed that both the specific mycelium growth rate and the cellulase biosynthesis rate of the recombinant were dramatically dominant over those of the two parents. in addition, the negative c ... | 1997 | 9429777 |
| influence of ferulic acid on the production of feruloyl esterases by aspergillus niger. | extracellular feruloyl esterases from the filamentous fungus aspergillus niger are induced by growth on oat spelt xylan (osx), which contains no detectable esterified ferulic acid. fae-iii accounted for most of the feruloyl esterase activity. addition of free ferulic acid to osx at the start of the culture induced fae-iii secretion a further 2.3-fold, and also induced other feruloyl esterases which could not be ascribed to fae-iii. wheat bran-(wb)-grown cultures, containing 1% (m/v) esterlinked ... | 1997 | 9435103 |
| purification and characterization of an alpha-l-rhamnosidase from aspergillus niger. | an enzyme with alpha-l-rhamnosidase activity was purified by anion exchange chromatography from an aspergillus niger commercial preparation. the alpha-l-rhamnosidase was shown to be n-glycosylated, and had a molecular mass of 85 kd on sodium dodecylsulfate-polyacrylamide gel electrophoresis of which approximately 12% was contributed by carbohydrate. the enzyme was optimally active at ph 4.5 and 65 degrees c. when tested towards p-nitrophenyl-alpha-l-rhamnopyranoside it showed km and vmax values ... | 1997 | 9435109 |
| single electron reduction of xenobiotic compounds by glucose oxidase from aspergillus niger. | various species of fungi express glucose oxidase that catalyzes formation of gluconolactone from glucose with concomitant, direct divalent reduction of molecular oxygen to hydrogen peroxide. a physiological function ascribed to this extracellular enzyme is production of hydrogen peroxide for use in lignin degradation catalyzed by lignin peroxidases. herein, we show that glucose oxidase can catalyze one-electron reduction of several different classes of xenobiotic compounds resulting in generatio ... | 1998 | 9436625 |
| purification and characterization of a beta-glucosidase from aspergillus niger. | the high-molar mass form of beta-glucosidase from aspergillus niger strain niab280 was purified to homogeneity with a 46-fold increase in purification by a combination of ammonium sulfate precipitation, hydrophobic interaction, ion-exchange and gel-filtration chromatography. the native and subunit molar mass was 330 and 110 kda, respectively. the ph and temperature optima were 4.6-5.3 and 70 degrees c, respectively. the k(m) and kcat for 4-nitrophenyl beta-d-glucopyranoside at 40 degrees c and p ... | 1997 | 9438354 |
| influence of calcium on fungal growth, hyphal morphology and citric acid production in aspergillus niger. | addition of 0.5 g/l cacl2 to the fermentation medium lowered the final biomass dry mass by 35% and increased the uptake of phosphate and sucrose, and the production of citric acid by 15, 35 and 50%, respectively. in a medium deprived of ca2+ the microorganism displayed both a pelleted and a filamentous form of growth, the hyphae being scarcely branched, without bulbous cells. an addition of ca2+ induced a pelleted form of growth, highly branched hyphae and numerous bulbous cells. bulbous cells g ... | 1997 | 9438355 |
| molecular and phenotypic characterization of aspergillus japonicus and aspergillus aculeatus strains with special regard to their mitochondrial dna polymorphisms. | forty aspergillus japonicus and a. aculeatus strains, most of them wild-type isolates, were examined using various molecular and phenotypic techniques. the rdnas proved to be invariable (even strains of the species a. aculeatus exhibited the same restriction profile), while the strains could be classified into seven different mtdna rflp groups. hybridisation data suggest that six of these mtdna types have certain common restriction sites, while mtdna type 7, which was exhibited by some a. aculea ... | 1997 | 9442274 |
| equine pulmonary mycosis due to aspergillus niger and rhizopus stolonifer. | invasive pulmonary mycosis caused by aspergillus niger and rhizopus stolonifer is reported in a 2-year-old horse, one of three that died after being housed in a disused, uncleaned stable. lesions were characterized by thrombosis of the blood vessels with haemorrhage and tissue necrosis. fungal hyphae were observed both in thrombosed vessels and in adjacent necrotic tissue. in culture media inoculated with lung samples and samples from the bedding hay, two types of colony were recorded and identi ... | 1997 | 9447480 |
| purification and the effect of manganese ions on the activity of carboxymethylcellulases from aspergillus niger and cellulomonas biazotea. | carboxymethylcellulases (cmcases) from aspergillus niger and cellulomonas biazotea were purified by a combination of ammonium sulfate precipitation, anion-exchange and gel-filtration chromatography with a 12- and 9-fold increase in the purification factor. the native and subunit molar mass of cmcase from a. niger were 40 and 25-57 kda, respectively, while those from c. biazotea were 23 and 20-30 kda, respectively. low concentrations of mn2+ activated the enzymes from both organisms (mixed activa ... | 1997 | 9449776 |
| stability and identification of active-site residues of carboxymethylcellulases from aspergillus niger and cellulomonas biazotea. | determination of the apparent pka's of purified carboxymethylcellulases from aspergillus niger and cellulomonas biazotea at different temperatures and in the presence of dioxane indicated two side chain carboxyl groups which controlled the limiting rate in both organisms. the thermostability of both enzymes slightly decreased with increasing ph from 5 to 75 but was unaffected in the presence of 0.5 mmol/l mn2+. the cmcase from c. biazotea had an activation energy of 35 kj/mol and a half-life of ... | 1997 | 9449777 |
| characterization of phytase produced by aspergillus niger. | the extracellular activity of aspergillus niger phytase at the end of the growth phase was 132 nkat/ml in a laboratory bioreactor. the purified enzyme has molar mass approximately 100 kda, ph optimum at 5.0, temperature optimum at 55 degrees c and high ph and temperature stability. the km for dodecasodium phytate, calcium phytate and 4-nitrophenyl phosphate are 0.44, 0.45 and 1.38 mmol/l, respectively. the enzyme is noncompetively inhibited by inorganic monophosphate (ki = 2.85 mmol/l) and by cu ... | 1997 | 9449782 |
| the tree-dimensional structure of aspergillus niger pectin lyase b at 1.7-a resolution. | the three-dimensional structure of aspergillus niger pectin lyase b (plb) has been determined by crystallographic techniques at a resolution of 1.7 a. the model, with all 359 amino acids and 339 water molecules, refines to a final crystallographic r factor of 16.5%. the polypeptide backbone folds into a large right-handed cylinder, termed a parallel beta helix. loops of various sizes and conformations protrude from the central helix and probably confer function. the largest loop of 53 residues f ... | 1998 | 9449837 |
| apical branching in a temperature sensitive mutant of aspergillus niger. | an apical branching, temperature-sensitive, mutant of aspergillus niger (ramosa-1) was isolated by uv mutagenesis. ramosa-1 has a wild type morphology at 23 degrees c, but branches apically when shifted to 34 degrees c. the cytological events leading to apical branching were recorded by video-enhanced phase contrast microscopy. the first event was a momentary, localized, cytoplasmic contraction lasting approximately 1 s. this contraction was seen as a sudden unidirectional movement of visible or ... | 1997 | 9454643 |
| detection of aspergillus ribosomal rna using biotinylated oligonucleotide probes. | aspergillosis continues to be a devastating disease entity that results in significant mortality in immunosuppressed patients. rapid diagnosis is often required to initiate appropriate therapy. although the histopathologist may be able to visualize fungal organisms in tissue specimens, the histology of aspergillus species may overlap with a variety of fungi, so diagnosis often relies on fungal cultures that can take weeks to complete. recently, an in situ hybridization assay targeting aspergillu ... | 1997 | 9458383 |
| some details of the reaction mechanism of glucoamylase from aspergillus niger--kinetic and structural studies on trp52-->phe and trp317-->phe mutants. | presteady and steady-state kinetic results on the interactions of a wild-type, and the mutant glucoamylases trp52-->phe and trp317-->phe, from aspergillus niger with maltose, maltotriose and maltotetraose have been obtained and analyzed. the results are compared with previous ones on the mutants, trp120-->phe and glu180-->gln, and with results obtained from structure energy minimization calculations based on known three-dimensional structural data. all results are in accordance with a three-step ... | 1997 | 9461285 |
| dynamic and structural properties of glucose oxidase enzyme. | the catalytic oxidation of beta-d-glucose by the enzyme glucose oxidase involves a redox change of the flavin coenzyme. the structure and the dynamics of the two extreme glucose oxidase forms were studied by using infrared absorption spectroscopy of the amide i'band, tryptophan fluorescence quenching and hydrogen isotopic exchange. the conversion of fad to fadh2 does not change the amount of alpha-helix present in the protein outer shell, but reorganizes a fraction of random coil to beta-sheet s ... | 1998 | 9463887 |
| substrate specificities of penicillium simplicissimum alpha-galactosidases. | the substrate specificities of three penicillium simplicissimum alpha-galactosidases, agli, aglii, and agliii, were determined by using various isolated galactose-containing oligosaccharides and polymeric galacto(gluco)mannans. agli released galactose from melibiose and raffinose-family oligosaccharides but the amount of galactose released was decreased from 96% to 35% by the increasing chain length of the substrate from raffinose to verbascose. it was able to release galactose linked to the non ... | 1998 | 9463945 |
| isolation and analysis of xlnr, encoding a transcriptional activator co-ordinating xylanolytic expression in aspergillus niger. | complementation by transformation of an aspergillus niger mutant lacking xylanolytic activity led to the isolation of the xlnr gene. the xlnr gene encodes a polypeptide of 875 amino acids capable of forming a zinc binuclear cluster domain with similarity to the zinc clusters of the gal4 superfamily of transcription factors. the xlnr-binding site 5'-ggctaaa-3' was deduced after electrophoretic mobility shift assays, dnase i footprinting and comparison of various xylanolytic promoters. the importa ... | 1998 | 9466262 |
| studies of lipase-catalyzed esterification reactions of some acetylenic fatty acids. | esterification of five positional isomers of acetylenic fatty acids [viz. 9:1(2a), 11:1(10a), 18:1(6a), 18:1(9a) and 22:1(13a)] of different chain lengths with n-butanol in n-hexane in the presence of eight different lipases [lipozyme im 20 (rhizomucor miehei), lipolase 100t (r. miehei), novozyme 435 (candida antarctica), ppl (porcine pancreatic lipase), ccl (c. cylindracea), ps-d (pseudomonas cepacia), lipase a-12 (aspergillus niger) and lipase ay-30 (c. rugosa)] was studied. 2-nonynoic acid wa ... | 1998 | 9470175 |
| flow sensing in mycelial fungi. | hyphae of a variety of mycelial fungi were shown to reorient their direction of growth to grow upstream in a continuous flowing current of liquid medium. among those tested fungi, aspergillus niger hyphae was most polarized towards the upstream. hyphae of a. niger which had been attached to poly-l-lysine coated plates on the base of a continuous-culture flow cell were exposed to a current of medium of flow rates in the range of 0-6400 microns s-1 for 1-4 h. hyphal tips quickly reoriented towards ... | 1997 | 9470224 |
| elimination of microorganisms from dental operatory compressed air. | compressed air is used to power high-speed handpieces, as well as to dry and clean surfaces in the oral cavity during patient treatment, in all dental operatories. the compressed air used in the dental operatories located in large institutions such as universities or hospitals is generally obtained from a central source, and is produced by continually running compressors. in operatories located in private practice settings, compressed air is obtained from small on-site air compressors, which may ... | 1998 | 9473876 |
| metabolism of polycyclic aromatic hydrocarbons by aspergillus niger. | aspergillus niger metabolised polycyclic aromatic hydrocarbons such as naphthalene, anthracene and phenanthrene. the maximum weight of mycelium was obtained at 8-10 days of incubation. tlc and hplc analysis revealed the accumulation of metabolites in resting cell culture. the metabolism of naphthalene and anthracene follows the gentisate pathway, where as phenenthrene was metabolised via protocatechuate in this organism. | 1997 | 9475084 |
| conservation of the active site motif in aspergillus niger (ficuum) ph 6.0 optimum acid phosphatase and kidney bean purple acid phosphatase. | aspergillus niger (ficuum) and the kidney bean purple acid phosphatases retained all the essential amino acids in the active site despite a low degree of total sequence homology. this high degree of homology in the sequence motif of a. niger fungal acid phosphatase (apase6) active site with kidney bean metallo phosphoesterase (kbpap) and the absence of the rhg-xrxp sequence motif indicates apase6 to be a metallophosphoesterase rather than a histidine acid phosphatase. | 1998 | 9480832 |
| aspergillus: a rare primary organism in soft-tissue infections. | nonclostridial necrotizing soft-tissue infections are usually polymicrobial, with greater than 90 per cent involving beta-hemolytic streptococci or coagulase-positive staphylococci. the remaining 10 per cent are usually due to gram-negative enteric pathogens. we describe the case of a 46-year-old woman with bilateral lower extremity fungal soft tissue infections. she underwent multiple surgical debridements of extensive gangrenous necrosis of the skin and subcutaneous fat associated with severe ... | 1998 | 9486882 |
| effect of microbial phytase on zinc bioavailability and cadmium and lead accumulation in growing rats. | this study evaluated the effect of increasing levels of dietary microbial phytase on the bioavailability of zinc and the accumulation of cadmium and lead in growing rats. five groups of seven albino rats (initial average weight 47 g) were housed individually and fed phytate-rich diets (7 g/kg) based on maize, soya bean meal, corn starch and soya bean oil over a 4-week experimental period. the basal diet contained 24 mg zinc (native concentration), 10 mg lead as pb(ch3coo)2.3h2o and 5 mg cadmium ... | 1998 | 9487359 |
| concentration- and time-dependent upregulation and release of the cytokines mip-2, kc, tnf, and mip-1alpha in rat alveolar macrophages by fungal spores implicated in airway inflammation. | inhalation of fungal spores has been shown to cause primary or secondary infection and respiratory inflammation and diseases such as allergic alveolitis, atopic asthma, and organic dust toxic syndrome, which are rarely reported in the absence of predisposing factors. biochemical and molecular markers of inflammation were measured in rat bronchial alveolar lavage cells (> 95% macrophages) following stimulation with fungal spores isolated from pathogenic and nonpathogenic fungi that have been impl ... | 1998 | 9490662 |
| pgae encodes a fourth member of the endopolygalacturonase gene family from aspergillus niger. | in the present study, the molecular and basic biochemical characterization of endopolygalacturonase e, the fourth aspergillus niger n400 endopolygalacturonase, is reported. the entire endopolygalacturonase e gene consists of 1293 bp interrupted by three short introns (50, 50, and 59 bp, respectively) as concluded from the cdna sequence. the deduced amino acid sequence comprises 378 residues that include 39 n-terminal amino acids of the prepropeptide. the calculated mr and pi of the mature protei ... | 1998 | 9492270 |
| [isolation and characterization of an evolutionary precursor of human monoamine oxidases a and b]. | an interesting flavoprotein-type monoamine oxidase (mao) was recently isolated from aspergillus niger and cloned by schilling and lerch (1995a,b) the properties of this mao, as well as a substantial part of its amino acid sequence resemble those of both mao a and b from higher animals, raising the possibility that it may be an evolutionary precursor of these mitochondrial enzymes. it differs from mao a and b in several respect, however, including the fact that it is soluble and of peroxisomal lo ... | 1997 | 9503562 |
| genetic analysis of resistance to fenpropimorph in aspergillus niger. | resistance to the morpholine-fungicide fenpropimorph was studied in aspergillus niger and a. nidulans. mass selection of conidia of a. nidulans on agar amended with the fungicide at different concentrations did not yield of resistant mutants, even after uv-treatment of the conidia. in contrast, similar experiments with a. niger generated many fenpropimorph-resistant mutants. the mutants displayed cross-resistance to fenpropidin and generally showed wild-type sensitivity to the unrelated toxicant ... | 1998 | 9506903 |
| ultrasonication: the way to achieve antimutagenic effect of carboxymethyl-chitin-glucan by oral administration. | carboxymethyl-chitin-glucan (cmcg) isolated from aspergillus niger was ultrasonicated to decrease its molecular weight. ultrasonicated cmcg with molecular weight 0.19 x 10(-5) was administered either intraperitoneally or orally prior to cyclophosphamide (cp) injection and its effect on the frequency of micronuclei in polychromatic erythrocytes of mouse bone marrow was evaluated. both ways of cmcg administration significantly decreased the clastogenic effect of cp. the protective effect of cmcg w ... | 1998 | 9508367 |
| recombination of mitochondrial dna without selection pressure among compatible strains of the aspergillus niger species aggregate. | previous mitochondrial transmission experiments between oligomycin-resistant and oligomycin-sensitive incompatible strains of the a. niger aggregate bearing various mtdna rflp profiles resulted in a great variety of mitochondrial recombinants under selection pressure. apart from the recombinant mtdnas, resistant clones harbouring unchanged rflp profiles of resistant donor mtdnas with the recipient nuclear backgrounds were rarely isolated. these strains were anastomosed with nuclearly isogenic ol ... | 1998 | 9508794 |
| brasilinolide a, a new macrolide antibiotic produced by nocardia brasiliensis: producing strain, isolation and biological activity. | a new 32-membered macrolide antibiotic, brasilinolide a was isolated from the fermentation broth of nocardia sp. ifm 0406. the producer was identified as nocardia brasiliensis. the antibiotic was only active against aspergillus niger, but not active against other fungi including yeasts as well as other filamentous like fungi and bacteria. brasilinolide a exerted an immunosuppressive activity in the assay system of a mixed lymphocyte reaction (mlr). | 1997 | 9510911 |
| [the antifungal activity of new quaternary ammonium compounds and the potentials for their use in biochemical research methods]. | antifungal activity of quaternary ammonium compounds and possibility to use these substances as antimicrobial stabilizers was studied. taking into consideration their ability to stabilize aqueous solutions of ascorbic acid, they can be used for a quantitative assays of total protein and bilirubin. | 1997 | 9511370 |
| new polymerized complexes of amino-triazole with transition metals as potential fungicidal drugs. | new synthesized polymerized complexes of 3-amino-1,2,4-triazole with transition metals such as cu+2, ni+2, co+2 and zn+2 were investigated for fungicidal activity. most of the tested complexes showed fungicidal activity which is not connected with activity of copper fungicides. | 1997 | 9511446 |
| novel microbial hydroxylation of 13-ethyl-17 beta-hydroxy-18,19-dinor-17 alpha-pregn-4-en-20-yn-3-one. | the microbial transformation of the dl and the d-enantiomer of 13-ethyl-17 beta-hydroxy-18,19-dinor-17 alpha-pregn-4-en-20-yn-3-one (1) were investigated. poor yields and poor resolutions were usually obtained for the hydroxylation reactions. transformation of 1 by cunninghamella blakesleeana gave 6 beta-, 7 beta-, 10 beta-, 15 alpha-hydroxy derivatives 4, 5, 6, 7, and 6 beta,10 beta-dihydroxy derivative 8; transformation of 1 by cunninghamella echinulata afforded 5, 6, and 8. biotransformation ... | 1998 | 9516718 |
| an improved colony-pcr method for filamentous fungi for amplification of pcr-fragments of several kilobases. | a method was developed to perform pcr directly on mycelial pellets or colonies treated with novozym 234. the method allows rapid screening of large numbers of transformants of both sporulating and non-sporulating fungi for the presence of (co)transforming plasmid copies or for specific genetic modifications such as gene disruption and site specific integration. pcr fragments of at least 3.2 kb can be obtained. using this method the identification of specific disruption mutants from aspergillus n ... | 1997 | 9519482 |
| genfold: a genetic algorithm for folding protein structures using nmr restraints. | we report the development and validation of the program genfold, a genetic algorithm that calculates protein structures using restraints obtained from nmr, such as distances derived from nuclear overhauser effects, and dihedral angles derived from coupling constants. the program has been tested on three proteins: the pou domain (a small three-helix dna-binding protein), bovine pancreatic trypsin inhibitor (bpti), and the starch-binding domain from aspergillus niger glucoamylase i, a 108-residue ... | 1998 | 9521126 |
| cobalt 60 radiation and growth of eleven species of micro-fungi from evolution canyon, lower nahal oren, israel. | eleven micro-fungal species isolated from both the north facing slope (nfs) and the south facing slope (sfs) of evolution canyon, lower nahal oren, israel, were examined for growth rates before and after exposure to 60co irradiation. species of alternaria, aspergillus, humicola, oidiodendron, and staphylotrichum from sfs grew faster than the nfs isolates while fusarium, sordaria, and stachybotrys grew at greater rates from the nfs than from the sfs. mucor and ulocladium isolates grew at the same ... | 1997 | 9523426 |
| production of pectinesterase and polygalacturonase by aspergillus niger in submerged and solid state systems. | production of pectinesterase and polygalacturonase by aspergillus niger was studied in submerged and solid-state fermentation systems. with pectin as a sole carbon source, pectinesterase and polygalacturonase production were four and six times higher respectively in a solid state system than in a submerged fermentation system and required a shorter time for enzyme production. the addition of glucose increased pectinesterase and polygalacturonase production in the solid state system but in submer ... | 1998 | 9523455 |