| [evaluation of aspergillus niger phytase and dietary phosphate in weaned piglets. 1. growth, blood serum and bone status]. | a high phytic acid diet (barley, wheat, soya bean meal, 4 g p/kg, of that 2/3 phytate p) without added phytase, with phytase supplement (1000 u/kg diet) or with supplementary phosphate (2,2g p/kg diet) was examined with 3 x 12 weaned piglets. the high dietary p level due to phosphate addition, significantly improved body weight gain and feed:gain ratio. the phytase effect on these criteria was small. the phytase but more the supplementary phosphate increased p concentration of serum. in case of ... | 1994 | 7668974 |
| [evaluation of aspergillus niger phytase and phosphate in weaned piglets. 2. content and gain of fat, energy, ash, ca and p in the animal body]. | a high phytic acid diet (barley, wheat, soya bean meal, 4 g p/kg diet, of that 2/3 phytate p) without added phytase, with phytase supplement (1000 u/kg diet) or with supplementary phosphate (2.2 g p/kg diet) was examined with 3 x 12 weaned piglets. the three diets contained 8 g ca/kg. at the end of experiment 6 pigs/group were slaughtered. in animal body (as empty body) the content and gain of ash, p, ca, protein and fat were detected. p supplementation and supplementary phytase had no effect on ... | 1995 | 7668982 |
| substrate binding ability of chemically inactivated pectinase for the substrate pectic acid. | pectinase (polygalacturonase) was purified from a commercial pectinase preparation from a mold. substrate binding of pectinase was measured by centrifugal affinity chromatography using an immobilized substrate, pectic acid. desorption of pectinase from the affinity matrix with the substrate pectin and pectic acid gave kd values of 5.3 and 8.5 mg/ml, respectively. chemical modification of pectinase by 1-ethyl-3-(3-dimethyl-aminopropyl)carbodiimide (edc) and diethyl pyrocarbonate (dep) caused a lo ... | 1995 | 7670184 |
| proteinase a from aspergillus niger. | | 1995 | 7674918 |
| specificity of the binding domain of glucoamylase 1. | glucoamylase 1 from aspergillus niger hydrolyses granular starch at an increased rate due to the presence of a c-terminal starch-binding domain. this domain was isolated and shown to bind to the malto-oligosaccharides glc2 to glc11 with a stoichiometry of 1 mol ligand/mol protein. the affinity for these ligands increased with increasing degree of polymerisation until glc9, above which no further increase was observed. we suggest that this indicates that for maximum affinity the substrate should ... | 1993 | 7679638 |
| pleuro-pulmonary aspergillosis. us and us-guided biopsy as an aid to diagnosis. | we reviewed the us findings and the diagnostic yield of fine-needle aspiration biopsy (fnab) for cytologic and microbiologic samples in 4 patients with pulmonary or pleural aspergillosis. all 3 apical aspergillus abscesses were round, hypoechoic with irregular margins and one contained echo-densities with shadowing consistent with air. one pleural empyema was oval and hypoechoic. cytology suggested inflammation in all cases and aspergillus hyphae were detected in 2 of 4 aspirates. culture of the ... | 1995 | 7710789 |
| fungus allergens inside and outside the residences of atopic and control children. | airborne fungi were collected during the peak fungus season, using the n6 andersen sampler inside and outside the homes of 46 asthmatic children, 20 atopic children, and 26 nonatopic control children in the taipei area. the geometric mean fungus concentrations of the asthmatic, atopic, and control groups were found to be 565, 411, and 608 colony-forming units (cfu) per m3 in the living rooms; 659, 464, and 602 cfu m3 in the bedrooms; and 547, 449, and 668 cfu m3 outdoors; respectively. aspergill ... | 1995 | 7717768 |
| immobilization of aspergillus niger xylanase on magnetic latex beads. | xylanase from pectinex 3xl was purified 70-fold by precipitation with an enteric polymer, eudragit s-100. the purified xylanase was immobilized on magnetic latex beads via carbodi-imide coupling. the immobilized preparation showed 80% of the total activity bound to the beads. the ph optimum remained unchanged at 6.0 and the km increased from 0.25 g/100 ml (free enzyme) to 0.39 g/100 ml on immobilization. immobilization resulted in significant thermal stability at 60 degrees c. the time course of ... | 1995 | 7718159 |
| in vitro antifungal and fungicidal spectra of a new pradimicin derivative, bms-181184. | a new pradimicin derivative, bms-181184, was compared with amphotericin b and fluconazole against 249 strains from 35 fungal species to determine its antifungal spectrum. antifungal testing was performed by the broth macrodilution reference method recommended by the national committee for clinical laboratory standards (document m27-p, 1992). bms-181184 mics for 97% of the 167 strains of candida spp., cryptococcus neoformans, torulopsis glabrata, and rhodotorula spp. tested were < or = 8 microgra ... | 1995 | 7726485 |
| amine oxidases from aspergillus niger: identification of a novel flavin-dependent enzyme. | upon induction with various amine sources, two different amine oxidases are expressed in the filamentous fungus aspergillus niger. the enzymes which can be separated by anion exchange chromatography exhibit a similar substrate specificity pattern. from cofactor and inhibitor analysis it was found that one amine oxidase is identical to the earlier reported copper-containing amine oxidase (yamada, h., adachi, o. and ogata, k. (1965) agric. biol. chem. 29, 912-917) with 6-hydroxydopa (topa) quinone ... | 1995 | 7727530 |
| superoxide from glucose oxidase or from nitroblue tetrazolium? | glucose oxidase reduces nitroblue tetrazolium, or ferricytochrome c, faster anaerobically than aerobically. this result is inconsistent with the conclusion that go2 can reduce o2 to o2- which is then responsible for the reduction of nbt and of cytochrome c. nevertheless, the aerobic reductions are partially inhibitable by superoxide dismutase. a scheme of reactions is proposed which explains why these electron acceptors cause an o2- production which does not occur in their absence when o2 is the ... | 1995 | 7733670 |
| resonance raman investigation of cyanide ligated beef liver and aspergillus niger catalases. | resonance raman spectroscopy has been used to investigate the properties of cyanide-bound beef liver catalase (blc) and aspergillus niger catalase (anc) in the ph range 4.9-11.5. evidence has been obtained for the binding of cyanide to both blc and anc in two binding geometries. the first conformer, exhibiting the nu[fe-cn] stretching mode at a higher frequency than the delta[fe-c-n] bending mode, exists as an essentially linear fe-c-n linkage. for both blc-cn and anc-cn, the nu[fe-cn] and delta ... | 1995 | 7737979 |
| purification and characterization of an extracellular aspartic proteinase from aspergillus fumigatus. | an aspartic proteinase (pep) from the culture supernatant of a clinical isolate of aspergillus fumigatus was purified to virtual homogeneity at a yield of 24%. the procedure involved affinity chromatography on pepstatin agarose, the interaction requiring a chaotropic salt (sodium trifluoroacetate) for complete elution of the enzyme. among 11 amino acids of the n-terminal region, nine were identical with the corresponding sequence of the aspartic proteinase aspergillopepsin a from aspergillus nig ... | 1994 | 7738725 |
| [a case of probable allergic bronchopulmonary aspergillosis due to aspergillus niger]. | we report a case of probable allergic bronchopulmonary aspergillosis (abpa) due to aspergillus niger. an 80-year-old woman was admitted to our hospital because of wheezing, expectoration of a mucous plug and atelectasis of the right lower lobe as seen on a chest x-ray film. the patient had eosinophilia and immediate wheal-and-flare skin reactivity to a. fumigatus. serum precipitating antibodies against a. niger and elevated serum ige, however, were absent. mucus impaction and bronchiectasis were ... | 1995 | 7739179 |
| fungitoxic effect of some organic volatile substances against fungi causing otomycosis. | the fungitoxic effect of seven volatile substances (ammonia, carbon disulphide, petroleum benzene, carbon dioxide, methanol, glacial acetic acid and hydrogen peroxide) against five fungi, i.e. aspergillus niger, a. flavus, absidia corymbifera, penicillium nigricans and candida albicans, was determined on the basis of their dry mycelial weight and sporulation or budding activity. these organisms were isolated from patients suffering from fungal infections of the ear. all the volatile substances t ... | 1994 | 7739663 |
| discrepancies between mic and mlc values of amphotericin b against isolates of aspergillus species. | there is little information addressing the phenomena of discrepancy between minimal inhibitory concentrations (mic) and minimal lethal concentrations (mlc) values of amphotericin b (amb) to clinical isolates of fungi. this study assessed in vitro activity of amb against 70 clinical isolates of aspergilli: 30 strains of aspergillus fumigatus, 20 strains of aspergillus flavus and 20 strains of aspergillus niger. susceptibility tests were accomplished using a macro broth dilution procedure, with sp ... | 1994 | 7739726 |
| production of hormones by fungi. | twenty species of filamentous fungi were tested for their gibberellin and sterol production, with emphasis on the action of some factors on these products. while all cultures produced both gibberellin and sterol in variable amounts, aspergillus flavus, a. niger, a. ochraceus, cladosporium cladosporioides, gibberella zeae, penicillium funiculosum, p. italicum and p. rubrum were the best producers. the isolates of a. niger isolated from soil and p. italicum isolated from citrus fruit were selected ... | 1994 | 7740983 |
| enhancement of inulinase production by aspergillus niger van teighem. | aspergillus niger van teighem, a soil isolate, was mutagenized by u.v. light. a mutant strain with 3 times increased productivity was generated on exposure of the parent strain to u.v. for 15 min. this mutant on further exposure to u.v. yielded second generation mutants with only marginal increase in inulinase productivity with respect to the parent mutant, but the best yield of 377 u ml-1 was considered promising for industrial use. | 1995 | 7744724 |
| seeds as natural matrices for immobilization of aspergillus niger mycelium producing pectinases. | a simple method for the immobilization of aspergillus niger mycelium producing polygalacturonase (pg) and pectinesterase (pe) is described. fungal conidia were immobilized on wheat, rye, barley, peas, buckwheat and mustards seeds. spongy mycelia overgrowing the seed surfaces on mineral medium with pectin produced extracellular pg and pe; the highest production was reached on the wheat carrier. some of the variables influencing the enzymatic activity have been optimized. after every 24 h, a cultu ... | 1995 | 7744727 |
| foreign dna sequences are received by a wild-type strain of aspergillus niger after co-culture with transgenic higher plants. | different transgenic plants of brassica napus, brassica nigra, datura innoxia and vicia narbonensis expressing the hph gene under the control of the 35s promoter were co-cultivated with mycelial material of aspergillus niger in microcosms under sterile conditions. a significantly higher number of hygromycin b-resistant colonies of re-isolated fungi was obtained if compared with co-cultures with non-transgenic plants. the hph gene and other foreign sequences could be detected in some of the resis ... | 1994 | 7750149 |
| a case of lymphocytic pneumonitis, myositis, and arthritis associated with exposure to aspergillus niger. | | 1995 | 7751502 |
| isolation and characterization of the glucose-6-phosphate dehydrogenase encoding gene (gsda) from aspergillus niger. | genomic and cdna clones encoding glucose-6-phosphate dehydrogenase (g6pd) were isolated from the fungus aspergillus niger. sequence analysis of the glucose-6-phosphate dehydrogenase gene (gsda) revealed an open reading frame of 1530 bp, encoding a protein of 58,951 kda. the gsda gene is interrupted by nine introns the most proximal of which is exceptionally large (348 bp). the region upstream of the atg contains several c+t-rich stretches. the two major and one minor transcription start points a ... | 1995 | 7753033 |
| production of cellulase and xylanase in a bubble column using immobilized aspergillus niger kks. | aspergillus niger kks, isolated from a farmland near suwon, was immobilized on celite and polyurethane foams. enzyme activities produced by the immobilized cell system in a bubble column were higher than that of shake-flask culture. the enzyme productivities were twice as high. beta-glucosidase, beta-xylosidase, and xylanase activities obtained in a bubble column were significant when the ground rice straw was used as a substrate. | 1995 | 7763052 |
| applications of immobilized lipases to transesterification and esterification reactions in nonaqueous systems. | lipases from candida cylindracea, aspergillus niger, and pseudomonas fluorescens were immobilized by adsorption on anion-exchange resin and diatomaceous earth using buffer or hexane as a reaction medium. the enzyme preparations were tested in the transesterification of triolein with lauric acid and the esterification of lauric acid with different alcohols. immobilized c. cylindracea preparations were more active when hexane was used as the reaction medium, and anion-exchange resin was a better s ... | 1993 | 7763454 |
| interaction of transport resistances with biochemical reaction in packed bed solid state fermenters: the effect of gaseous concentration gradients. | mass transfer plays an important role in solid state fermentation (ssf) systems. earlier work on ssf in tray bioreactors indicated that steep gaseous concentration gradients developed within the substrate bed, owing to mass transfer resistances, which may adversely affect the bioreactor performance. for all practical purposes these gradients have been eliminated using a packed bed column bioreactor with forced aeration. gaseous concentrations (oxygen and carbon dioxide) and enzyme activities wer ... | 1993 | 7763530 |
| automatic evaluation of antifungal volatile compounds on the basis of the dynamic growth process of a single hypha. | an automatic analysing system was developed and employed for the evaluation of antifungal activity of volatile compounds in the gas phase. aspergillus niger was inoculated on agar medium in the reaction vessel. the reaction vessel was incubated at 28 degrees c for 24 h and then a volatile compound was introduced into the vessel either in a batch or flow manner. the antifungal activity of the respective compounds estimated in situ was expressed by the dynamic response parameters of a single hypha ... | 1993 | 7763535 |
| production of gluconic acid by aspergillus niger immobilized on polyurethane foam. | production of gluconic acid by cells of aspergillus niger immobilized on polyurethane foam was studied in repeated-batch shake-flask and bubble-column fermentations. for passive immobilization, various amounts of polyurethane foam and spore suspension were tested in order to obtain a suitable combination for optimal concentration of immobilized biomass. immobilized cells were successfully reused with higher levels of product formation being maintained for longer period (65-70 h) than free cells. ... | 1993 | 7763710 |
| determination of anti-aspergillus activity of antifungal agents based on the dynamic growth rate of a single hypha. | the dynamic growth rate of a single hypha of aspergillus niger was analysed using an automatic system. a colony of a. niger was in contact with saline, saline containing an antifungal agent, and flushing saline, in sequence. the growth rate of a test hypha selected arbitrarily from the colony responded dynamically to the antifungal agent. the minimum concentration that caused the complete inhibition of hyphal growth was defined as the minimum inhibitory concentration (mic). the mic values obtain ... | 1993 | 7763718 |
| structure of malformin b, a phytotoxic metabolite produced by aspergillus niger. | malformin b, produced by aspergillus niger, was separated into six compounds by hplc. their structures were determined by amino acid analyses, and by mass spectral and two-dimensional nmr experiments to be cyclic pentapeptides structurally related to malformin a1. both the nmr and ms/ms experiments suggest cyclo-d-cysteinyl-d-cysteinyl-l-amino acid-d-amino acid-l-amino acid as the essential structure of malformins. | 1993 | 7763777 |
| formation of beta-fructosyl compounds of pyridoxine in growing culture of aspergillus niger. | two pyridoxine compounds were found to be formed in a culture filtrate of aspergillus niger and a. sydowi, when grown in a medium containing sucrose and pyridoxine. each of the two compounds i and ii was obtained as a white powdered preparation by preparative paper chromatography, gel filtration on toyopearl hw-40s and sephadex g-10 columns, deae-cellulose column chromatography, and lyophilization. compounds i and ii were identified as 5'-o-(beta-d-fructofuranosyl)-pyridoxine and 5'-o-[beta-d-fr ... | 1993 | 7763873 |
| purification and some properties of intracellular alpha-l-arabinofuranosidase from aspergillus niger 5-16. | alpha-l-arabinofuranosidase was purified from a cell-free extract of aspergillus niger 5-16 by chromatographies on deae-toyopearl, sp-toyopearl, ultro-gel aca 44, mono p, and tsk-gel g3000sw. the final preparation thus obtained showed a single band on sds-polyacrylamide gel electrophoresis. the molecular weight and isoelectric point were 67,000 by sds-polyacrylamide gel electrophoresis and ph 3.5 by isoelectric focusing. the alpha-l-arabinofuranosidase contained amino acids in the order of asx > ... | 1993 | 7763988 |
| cloning of the aspergillus niger gene encoding alpha-l-arabinofuranosidase a. | using l-arabitol as an inducer, simple induction conditions were established that resulted in high-level expression of alpha-l-arabinofuranosidase a by an aspergillus niger d-xylulose kinase mutant strain. these conditions were adapted to construct a cdna expression library from which an alpha-l-arabinofuranosidase a cdna clone was isolated using specific antiserum. the corresponding gene encoding alpha-l-arabinofuranosidase a (abfa) was isolated from a genomic library and cloned into a high cop ... | 1993 | 7764056 |
| use of aspergillus overproducing mutants, cured for integrated plasmid, to overproduce heterologous proteins. | aspergillus niger var. awamori was previously transformed with a vector designed to express a fused glucoamylase-prochymosin gene and bearing the neurospora crassa pyr4 gene as a selectable marker. mutant strains that overproduced the glucoamylase-prochymosin fusion protein were derived from one of the transformants. despite the fact that the expression vector was integrated into the genome of these strains it was possible to obtain strains from which the vector sequences had been removed. this ... | 1993 | 7764120 |
| secretion of heterologous proteins by aspergillus niger: production of active human interleukin-6 in a protease-deficient mutant by kex2-like processing of a glucoamylase-hil6 fusion protein. | to develop improved methods for heterologous protein production in aspergillus niger, we studied the secretion of human interleukin-6 (hil6). since in vitro experiments with culture medium revealed that hil6 was rapidly degraded, several protease-deficient strains of a. niger were isolated and tested for reduced degradation of hil6 compared with the wild-type strain. the mutant strain giving the least degradative effect on hil6 (designated ab1.13) was transformed with several hil6-expression pla ... | 1993 | 7764298 |
| covalent immobilization of aspergillus niger on phema membrane: application to continuous flow reactors. | poly(2-hydroxyethyl methacrylate) (phema) membrane was prepared via photopolymerization and activated with epichlorohydrin. the conidia of aspergillus niger strains (wild type 'nrrl-3' and genetically improved strain 'nrrl-3/2-2a') were covalently-immobilized on the membranes. uniform growth of a. niger cells on membrane surfaces was verified by sem. the glucose oxidase (god) activity of the immobilized cells was determined in a continuous flow membrane reactor (cfmr) by assaying for hydrogen pe ... | 1993 | 7764311 |
| molecular cloning, expression and structure of the endo-1,5-alpha-l-arabinase gene of aspergillus niger. | secretion of endo-1,5-alpha-l-arabinase a (abn a) by an aspergillus niger xylulose kinase mutant upon mycelium transfer to medium containing l-arabitol was immunochemically followed with time to monitor its induction profile. a cdna expression library was made from polya+ rna isolated from the induced mycelium. this library was immunochemically screened and one abn a specific clone emerged. the corresponding abna gene was isolated from an a. niger genomic library. upon southern blot analysis, a ... | 1993 | 7764386 |
| interaction of transport resistances with biochemical reaction in packed-bed solid-state fermentors: effect of temperature gradients. | in solid-state fermentation, the interaction of transport phenomena with biochemical reactions has a considerable effect on the productivity of the bioreactor. previous work on solid-state fermentation in tray fermentors in our laboratory indicated that heat transfer resistance results in steep temperature gradients within the solid substrate bed, which in turn adversely affect the biochemical reaction and enzyme activity. this problem of heat accumulation during the course of fermentation has b ... | 1994 | 7764601 |
| physiological optimization of secreted protein production by aspergillus niger. | physiological factors affecting hen eggwhite lysozyme and native glucoamylase production by aspergillus niger have been examined in batch culture. expression of the genes encoding both proteins was controlled by the glucoamylase promoter. in standard expression medium (acms/n/p), secreted lysozyme yields were found to be maximal at 20-25 degrees c (8-10 mg l-1) and markedly reduced at 30-37 degrees c (3-5 mg l-1). production of lysozyme exhibited similar induction or repression profiles to that ... | 1994 | 7764633 |
| enzyme production by recombinant aspergillus. | the use of molds, principally a. niger and t. reesei, in the production of heterologous proteins is becoming more successful. the high levels expected for commercial success have already been attained with a limited number of proteins, and other examples are bound to follow. it must be remembered that, although yields will always need to be maximized, the yield required for a bulk enzyme will be much higher than that for a high-value therapeutic protein. a commercial application is not the only ... | 1994 | 7764770 |
| strain improvement of chymosin-producing strains of aspergillus niger var. awamori using parasexual recombination. | parasexual recombination was used to obtain improved chymosin-producing strains and to perform genetic analysis on existing strains. chlorate resistance was used to select for a variety of spontaneous nitrate assimilation pathway mutations in strains previously improved for chymosin production using classical strain improvement methods including mutation and screening, and selection for 2-deoxyglucose resistance (dgr). diploids of these improved strains were generated via parasexual recombinatio ... | 1994 | 7764791 |
| a simple and nondestructive method for the separation of polysaccharides from beta-glucosidase produced extracellularly by aspergillus niger. | an apparatus based on electrophoresis has been devised that removes noncovalently bound polysaccharides from extracellular proteins of aspergillus niger with concomitant partial beta-glucosidase purification and concentration. the apparatus consists of a series of three chambers separated by polyacrylamide gels. dialyzed and concentrated crude extract of aspergillus niger containing beta-glucosidase was poured into the middle chamber, while smaller anodic and cathodic chambers contained buffer. ... | 1994 | 7765232 |
| evaluation of molecular and genetic approaches to generate glucoamylase overproducing strains of aspergillus niger. | to evaluate the possibility of improving glucoamylase (gla) production in aspergillus niger strains carrying multiple copies of the gla encoding gene (glaa), additional glaa copies were introduced either by genetic recombination or retransformation. for strains to be used in such experiments a genetic analysis was first carried out. the results of this analysis clearly revealed that in each transformant integration had occurred at a chromosome corresponding to a single linkage group (lg). the gl ... | 1994 | 7765235 |
| classification of some alpha-glucosidases and alpha-xylosidases on the basis of substrate specificity. | three alpha-glucosidases which passed under the names of transglucosidase (from aspergillus niger), maltase (from brewers yeast), and isomaltase (from bakers yeast) for reasons of their substrate specificities and transfer actions, were purified to electrophoretically pure states. these purified alpha-glucosidases were made uniform in the hydrolyzing activities using p-nitrophenyl alpha-glucopyranoside (alpha-p-npg) and were reacted with p-nitrophenyl alpha-xylopyranoside (alpha-p-npx) or isopri ... | 1994 | 7765271 |
| total syntheses of (2s)-antafumicins a and b. | to clarify the absolute configurations of antafumicins a and b, which are antifungal substances from aspergillus niger nh-401, the total synthesis of (2s)-antafumicins was accomplished by starting from (s)-malic acid in 12 steps. based upon the physicochemical data of the synthetic samples, the absolute configurations of naturally occurring antafumicins a and b were determined as (2r,4s)- and (2r,4r)-4-(3-acetyl-2,6-dihydroxyphenyl)-2-methoxy-4-butanolide, respectively. | 1994 | 7765481 |
| gene expression in filamentous fungi. expression of pectinases and glucose oxidase in aspergillus niger. | | 1995 | 7765534 |
| transformation of intact aspergillus niger by electroporation. | a new rapid transformation system for aspergillus niger that uses electroporation to render intact germinating conidia permeable to dna is described. the transformant colonies appeared earlier than transformants obtained by the protoplast-forming method. without pretreatment of the conidia the transformation frequencies were 1.2 colonies per micrograms of integrative vector and 100 colonies per micrograms of plasmid dna. when the conidia were treated with a dilute solution of fungal cell wall ly ... | 1994 | 7765715 |
| metabolism of the polycyclic aromatic hydrocarbon pyrene by aspergillus niger sk 9317. | the metabolism of pyrene, a polycyclic aromatic hydrocarbon consisting of four rings, by aspergillus niger sk 9317 was investigated. the metabolites formed were isolated and identified as 1-hydroxypyrene, 1,6- and 1,8-pyrenequinone, 1,6- and 1,8-dihydroxypyrene, 1-pyrenyl sulphate and 1-hydroxy-8-pyrenyl sulphate. this is the first report of 1-hydroxy-8-pyrenyl as a metabolite in the microbial metabolism of pyrene. the results suggest that a. niger metabolizes pyrene by cytochrome p-450 monooxyg ... | 1994 | 7765738 |
| purification and molecular characterization of a soybean polygalacturonase-inhibiting protein. | a polygalacturonase-inhibiting protein (pgip) was detected in soybean (glycine max (l.) merr.) seedlings. the protein was purified from germinating seeds and appeared to consist of at least three components with very close molecular weights (between 37 and 40 kda) but each showing a unique n-terminal sequence. primers specific for n-terminal and c-terminal nucleotide sequences of field bean (phaseolus vulgaris l.) pgip were used in a polymerase chain reaction (pcr) on soybean dna, and only one a ... | 1994 | 7765794 |
| antifungal effects of allium sativum (garlic) extract against the aspergillus species involved in otomycosis. | otomycosis due to saprophytic keratolytic fungi represents a small percentage of clinical external otitis. although there are certain antibacterial and antifungal agents available, they usually are very caustic, potentially ototoxic and cannot be used if the ear drum is perforated. garlic is utilized as a folk medicine in many countries for its antimicrobial and other beneficial properties. in response to a lack of otic preparations, the authors studied the efficacy of garlic extracts against th ... | 1995 | 7765862 |
| metabolism of dimethylterephthalate by aspergillus niger. | aspergillus niger (ag-1) metabolized dimethylterephthalate through monomethylterephthalate, terephthalate and protocatechuate. degradation of dimethylterephthalate was followed by extraction of residual dimethylterephthalate from the spent medium. the quantitative uv analysis showed that 58% of the dimethylterephthalate supplement was taken up in 144 h. the metabolites were isolated from resting cell cultures. thin layer chromatography analysis of the extract revealed the presence of two interme ... | 1995 | 7765891 |
| progesterone transformation as a diagnostic feature in the classification of the aspergillus niger group. | fifty-five isolates of nine species and two species varieties (5 isolates each) of the aspergillus niger group were tested for progesterone transformation. generally, all isolates of the different species transformed progesterone to 21-hydroxyprogesterone. in addition, the isolates of seven species have the capacity to hydroxylate progesterone to 11 alpha-hydroxyprogesterone. a systematic variation could be observed between the tested species of the aspergillus niger group with respect to the tr ... | 1995 | 7766120 |
| citric acid production by aspergillus niger in surface culture on inulin. | aspergillus niger produces citric acid during surface fermentation on inulin, a reserve carbohydrate of plant tubers. citric acid yields can be improved by airflow over the surface of the fermentation but yields from inulin are 20-30% lower than from sucrose, the traditional commercial substrate. | 1995 | 7766122 |
| growth behaviour and glucoamylase production by aspergillus niger n402 and a glucoamylase overproducing transformant in recycling culture without a nitrogen source. | when wild-type aspergillus niger n402 and a glucoamylase-overproducing transformant were grown in recycling culture without a nitrogen source, hyphal tip extension and glucoamylase production still occurred, but overproduction of glucoamylase by the transformant strain stopped. the mycelium retained a low metabolic activity. light micrographs of mycelial samples showed that some hyphae were broken at their tip and partially empty, while after continuing recycling fermentation for more than 500 h ... | 1995 | 7766124 |
| cloning, sequencing and heterologous expression of the monoamine oxidase gene from aspergillus niger. | the gene encoding the flavin-containing monoamine oxidase (mao-n) of the filamentous fungus aspergillus niger was cloned. mao-n is the first nonvertebrate monoamine oxidase described to date. three partial cdna clones, isolated from an expression library, were used to identify and clone the structural gene (maon) from an a. niger genomic dna library. the maon gene was sequenced, and analysis revealed an open reading frame that codes for a protein of 495 amino acids with a calculated molecular ma ... | 1995 | 7770050 |
| opportunistic pulmonary infections with fludarabine in previously treated patients with low-grade lymphoid malignancies: a role for pneumocystis carinii pneumonia prophylaxis. | the high incidence of opportunistic pulmonary infections in fludarabine-treated patients at walter reed army medical center (wramc) and in the literature are described. a cancerlit search of fludarabine from june 1983-april 1994 with subsequent cross referencing and a retrospective review of all patients receiving fludarabine at wramc was performed. a total of 2,269 patients with low-grade lymphoid malignancies who received 7,547 + cycles of fludarabine were identified from the literature. seven ... | 1995 | 7771465 |
| expression and secretion of alpha-amylase and glucoamylase in saccharomyces cerevisiae. | alpha-amylase genes of bacillus licheniformis and glucoamylase cdna of aspergillus niger were ligated to a e. coli-yeast shuttle vector. the resultant plasmid was used to transform saccharomyces cerevisiae to construct starch-degrading yeast strain. the results of enzyme activity assay and enzyme property analysis show that alpha-amylase and glucoamylase genes have been expressed simultaneously in yeast under the control of promoters and terminators of yeast mf-alpha 1 factor and pgk genes and o ... | 1994 | 7780020 |
| transglucosylation of a fungal alpha-glucosidase. the enzyme properties and correlation of isomaltooligosaccharide production. | | 1995 | 7785860 |
| molecular cloning of a cdna for proctase b from aspergillus niger var. macrosporus and sequence comparison with other aspergillopepsins i. | a cdna for proctase b from aspergillus niger var. macrosporus was isolated and sequenced. the deduced amino acid sequence (394 residues) of the preproform of the enzyme was highly homologous (98% identify) with those of aspergillopepsins i from a. awamori and a. saitoi, and moderately homologous (68% identity) with that of a. oryzae. most of the sequence differences were found in the carboxyl-terminal domain. | 1995 | 7787314 |
| identification of the aminocatechol a-3253 as an in vitro poison of dna topoisomerase i from candida albicans. | the aminocatechol a-3253 is active against several pathogenic fungi, including candida albicans, cryptococcus albidus, and aspergillus niger. a-3253 interferes with both the in vitro biosynthesis of (1,3)-beta-glucan and the activity of topoisomerases i isolated from candida spp. it is likely that one or more of the enzymes involved in glucan biosynthesis rather than topoisomerase i is the primary intracellular target of a-3253, since a strain of saccharomyces cerevisiae lacking topoisomerase i ... | 1995 | 7793856 |
| inactivation of an animal and a fungal catalase by hydrogen peroxide. | we have quantitatively compared the rates of peroxide-dependent inactivation of bovine liver catalase and aspergillus niger catalase as class representatives of catalases that contain tightly bound nadph and those that do not. inactivation of these catalases in the presence of ethanol has also been quantitated in an effort to assess the importance of compound ii, an inactive form of bovine liver catalase, in the inactivation reaction. the values of k2, the second-order rate constant for inactiva ... | 1995 | 7793971 |
| enzymic synthesis of the trisaccharide core region of the carbohydrate chain of n-glycoprotein. | transmannosylation from mannotriose (man beta 1-4man beta 1-4man) to the 4-position at the nonreducing end n-acetylglucosaminyl residue of n,n'-diacetylchitobiose was regioselectively induced through the use of beta-d-mannanase from aspergillus niger. the enzyme formed the trisaccharide man beta 1-4glcnac beta 1-4glcnac (3.7% of the enzyme-catalysed net decrease of n,n'-diacetylchitobiose) from mannotriose as a donor and n,n'-diacetylchitobiose as an acceptor. mannobiose (man beta 1-4man) was al ... | 1994 | 7804000 |
| degradation of feruloylated oligosaccharides from sugar-beet pulp and wheat bran by ferulic acid esterases from aspergillus niger. | the activity of two forms of ferulic acid esterase (fae) from aspergillus niger on a synthetic feruloylated substrate (methyl ferulate) and on 11 different feruloylated oligosaccharides from sugar-beet pulp and wheat bran was determined. the enzymes exhibited different specificities for the various feruloylated substrates and were more active on certain substrates of cell-wall origin than on methyl ferulate. both enzymes preferred the arabinose residue to which ferulic acid is attached in the fu ... | 1994 | 7805053 |
| purification and properties of an exo-(1-->3)-beta-d-galactanase from aspergillus niger. | an exo-(1-->3)-beta-d-galactanase was purified by six chromatographic steps from a culture supernatant of aspergillus niger. its apparent molecular mass was 66 kda, as estimated by sds-page analysis. the purified enzyme had no detectable activity on various p-nitrophenyl glycosides and on native plant polysaccharides but exhibited a high activity on a (1-->3)-beta-d-linked galactan backbone obtained after partial acid hydrolysis and two smith degradations of gum arabic. the optimum conditions we ... | 1994 | 7805066 |
| thermosensitive mutants of aspergillus awamori glucoamylase by random mutagenesis: inactivation kinetics and structural interpretation. | seven thermosensitive glucoamylase mutants generated by random mutagenesis and expressed in saccharomyces cerevisiae were sequenced and their inactivation kinetics were determined. wild-type glucoamylase expressed in s. cerevisiae was more glycosylated and more stable than the native aspergillus niger enzyme. all mutants had lower free energies of inactivation than wild-type glucoamylase. in the ala39-->val, ala302-->val and leu410-->phe mutants, small hydrophobic residues were replaced by large ... | 1994 | 7809026 |
| disinfection efficacy in an integrated ultraviolet light contact lens care system. | we evaluated a new integrated contact lens care system that combines fluid turbulence for lens cleaning with ultraviolet (uv) light for solution sterilization. the ultraviolet light system was used to clean and disinfect 42 soft contact lenses (water contents: 38.6%, 43%, 55%, and 70%) and two rigid gas permeable lenses. test lenses were contaminated with 10(6) cells/ml of bacillus pumilus, aspergillus niger, pseudomonas aeruginosa, and acanthamoeba castellanii and subjected to a 15-minute clean ... | 1994 | 7820920 |
| monitoring the activity of glucose oxidase during the cultivation of aspergillus niger using novel amperometric sensor with 1, 1'-dimethylferricinium as a mediator. | 1, 1'-dimethylferricinium (dmf+), a deep blue, and stable mediator, was prepared from a water-soluble 1, 1'-dimethylferrocene(dmf):2-hydroxypropyl- beta-cyclodextrin complex via enzymatic oxidation using immobilised bilirubin oxidase. this mediator was superior to other soluble ferrocenes, notably carboxyferrocene, in terms of both solubility (110 mm vs 0.5 mm) and oxidation potential (150 mv vs 300 mv against ag/agcl). although the cyclic voltammogram of dmf+ was electrochemically equivalent to ... | 1994 | 7826581 |
| heterologous expression of the cytotoxin restriction in aspergillus nidulans and aspergillus niger. | the cdna clone of restrictocin was placed under the control of the glucoamylase promoter from aspergillus awamori and was transformed into aspergillus nidulans and aspergillus niger. site-specific changes were introduced into cdna constructs and these were transformed into a. nidulans. the secretion signal sequence was deleted from one form of the gene and three mutations introduced single amino acid substitutions into the protein. culture conditions were optimized for maximum expression levels ... | 1994 | 7827506 |
| cloning, characterization and expression of pepf, a gene encoding a serine carboxypeptidase from aspergillus niger. | we have cloned a gene (pepf) encoding a serine carboxypeptidase, proteinase f (pepf), from aspergillus niger. the sequences were identified in a phage lambda genomic dna library using a synthetic probe based on the n-terminal sequence of pepf. nucleotide sequence data from pepf genomic and cdna clones reveals that it is composed of four exons of 199, 283, 227 and 881 bp, interrupted by three introns of 53, 69 and 59 bp. the sequence of pepf codes for a polypeptide of 530 amino acids (aa), of whi ... | 1994 | 7828908 |
| liposomal amphotericin b prevents invasive fungal infections in liver transplant recipients. a randomized, placebo-controlled study. | eighty-six consecutive liver transplant recipients were prospectively randomized in a double-blind, placebo-controlled antifungal prophylaxis study. seventy-seven patients received 5 days of prophylaxis starting during the transplantation with either liposomal amphotericin b (ambisome) 1 mg/kg/day or placebo. among 40 ambisome-treated patients, no invasive candida infection was seen during the first month, compared with 5 invasive candida albicans infections among 37 control patients (p < 0.05). ... | 1995 | 7839427 |
| [the decomposition of maillard reaction products by amylolytic enzymes. 1. reversible inhibition of alpha- and glucoamylase and alpha-glucosidase by oligosaccharide amidori compounds]. | the influence of amadori-compounds (fructosyl-, maltulosyl- and maltotriulosylglycin) on the activity of the enzymes alpha-glucosidase (from saccharomyces cerevisiae), glucoamylase (from aspergillus niger) and alpha-amylase (from porcine pancreas) was studied. fructosylglycin was not hydrolyzed by all three enzymes. alpha-glucosidase hydrolyzes maltulosylglycin 10 times slower than maltotriulosylglycin. glucoamylase and alpha-amylase catalyze only the cleavage of maltotriulosylglycin to form glu ... | 1994 | 7839734 |
| [effect of cyclosporin on various metabolic processes in fungi]. | sensitivity of the representatives of aspergillus and piricularia to various concentrations of cyclosporine (in the submerged culture) was studied for choosing the test object for the subcellular investigation of the mechanism of the cyclosporine antifungal action. changes in the main physiological and biochemical parameters of the fungal cells under the action of cyclosporine in concentrations of 10 to 80 micrograms per 1 ml of the medium were characterized. low concentrations of cyclosporine ( ... | 1994 | 7840706 |
| protein targeting and secretion in filamentous fungi. a progress report. | although the application of filamentous fungi, such as aspergillus niger for the production of extracellular proteins is well established for several decades, hardly any information is available about the molecular mechanisms of the process of protein secretion in these organisms. two lines of research initiated towards a systematic analysis of the mechanism of protein targeting and secretion are presented in this paper. 1--to study routing and targeting of proteins in filamentous fungi the avai ... | 1994 | 7847888 |
| strategies for improving heterologous protein production from filamentous fungi. | despite the naturally high capacity for protein secretion by many species of filamentous fungi, secreted yields of many heterologous proteins have been comparatively low. the strategies for yield improvement have included the use of strong homologous promoters, increased gene copy number, gene fusions with a gene encoding a naturally well-secreted protein, protease-deficient host strains and screening for high yields following random mutagenesis. such approaches have been effective with some tar ... | 1994 | 7847891 |
| evidence for superoxide radical production by a simple flavoprotein: glucose oxidase. | nitroblue tetrazolium was reduced to blue formazan during the oxidation of glucose by glucose oxidase. the rate of blue color formation was dependent on the concentrations of glucose, nitroblue tetrazolium and glucose oxidase. the rate of the reaction was negligible below ph 8.4, but sharply increased with increasing ph. the reduction of nitroblue tetrazolium was inhibited by superoxide dismutase, consistent with the participation of superoxide anion radical in the reaction. | 1994 | 7849633 |
| [contamination of archives by filamentous fungi and their evaluation for potential pathogenicity]. | the results of microbiological examinations of dust samples collected from mortgage registers in the court archives are presented. in the samples examined filamentous fungi of penicillium genus were observed as well as cladosporium herbarum, geotrichum candidum, cephalosporium glutineum, mucor racemosus, trichoderma viride and aspergillus niger. filamentous fungi of penicillium genus occurred in the highest concentration accounting for 350,000 cfu/g. the levels of the remaining fungi were lower- ... | 1994 | 7854106 |
| [therapy with ciclopirox lacquer of onychomycoses caused by molds]. | 60 patients, suffering from an onychomycosis produced by molds were treated for a maximum of 6 months with ciclopirox nail lacquer (8%). these molds determined by culture were scopulariopsis brevicaulis (51 x), aspergillus niger (6 x), aspergillus fumigatus (2 x) and hendersonula toruloidea. anamnesis gave no hints, why molds were the causing fungi of onychomycosis. the achieved mycological cure rate was determined with 90% (culture) respectively 85% (koh preparation). the local treatment with c ... | 1994 | 7854374 |
| microbiological transformations--xxix. enantioselective hydrolysis of epoxides using microorganisms: a mechanistic study. | the regio- and stereochemistry of the hydrolysis of styrene oxide 1 by two fungi: aspergillus niger and beauveria sulfurescens, were studied using h2(18)o labelling experiments. also, the kinetic parameters of these hydrolyses were determined. we conclude that the epoxide hydrolases of these two fungi operate via different mechanisms. | 1994 | 7858966 |
| [elimination of microscopic filamentous fungi with disinfectants]. | the antifungal effectivity of three single-component (persteril, septonex, glutaraldehyd) and of three combined (persteril+septonex, pesteril+glutaraldehyd, glutaraldehyd+septonex) commercially available disinfectants was monitored by the diffuse method on five fen of the microscopic filamentous fungi aspergillus alternata, aspergillus niger, mucor fragillis, fusarium moniliforme, penicillium glabrum. the highest antifungal activity was observed in 2% persteril while 2% persteril + 1% septonex w ... | 1994 | 7863573 |
| effect of polyols and sugars on heat-induced flavin dissociation in glucose oxidase. | a thermodynamic investigation was carried out on heat-induced flavin dissociation in aspergillus niger glucose oxidase. experimental measurements performed by difference spectroscopy showed that the dissociation of the fad cofactors is a highly cooperative process and is probably related to the extended conformational changes resulting from protein unfolding. microenvironmental modifications attained by the addition of polyhydric compounds (glycerol, fructose, sucrose and sorbitol) from 10 to 30 ... | 1994 | 7866296 |
| [infectious external otitis: etiology in the terrassa region, culture methods, and considerations on otomycosis]. | the etiology of infections of the outer ear was studied in the area of terrassa (barcelona) over a six-year period (1987-1992). a total of 1419 samples of ear discharge were processed. traditional culture media were used to isolate the microorganisms as well as a modified culture medium prepared by us (apa). usual methods were used to identify the microorganisms. the results show pseudomonas aeruginosa to be the most frequently isolated microorganism. 76.5% of the otitis studied were unimicrobia ... | 1994 | 7873104 |
| interactions of enzymes and fungi with crosslinked polyurethanes prepared for biomedical applications. | shelf life and long-term environmental stability of polyurethanes intended for percutaneous applications and various biomedical applications are largely depend on their resistance to fungal attack and growth. two classes of aliphatic crosslinked polyurethanes based on hexamethylene diisocyanate (hdi) and bicyclo-hexyl-methane diisocyanate (sm di) were subjected to cell-free enzymatic degradation using hydrolytic and oxidative enzymes and to fungal attack and fungal growth using aspergillus niger ... | 1994 | 7877571 |
| a human erythrocyte-derived growth-promoting factor with a wide target cell spectrum: identification as catalase. | we have reported previously that a factor with a molecular weight of 53,000 under sds-polyacrylamide gel electrophoresis purified from human erythrocyte extracts promoted the growth of a wide variety of cell types from different species, including t cells, b cells, myeloid leukemia cells, melanoma cells, and mastocytoma cells, as well as normal and transformed fibroblast cells. in the present study, amino acid sequence analysis revealed that this factor has homology with human catalase. the puri ... | 1995 | 7882369 |
| cloning and characterization of a novel polygalacturonase-encoding gene from aspergillus parasiticus. | pectinases produced by aspergillus flavus and a. parasiticus are believed to play a significant role in the ability of these fungi to spread in cotton bolls and other crops. utilizing a dna probe, generated by pcr, of the aspergillus niger pgaii gene, we have isolated a novel, constitutively expressed polygalacturonase (pg)-encoding gene (peca) from an a. parasiticus cdna library. dna sequence analysis and the deduced amino acid (aa) sequence of peca demonstrated significant identity at the nucl ... | 1995 | 7883176 |
| expression and secretion of glucoamylase of aspergillus niger in saccharomyces cerevisiae. | glucoamylase cdna synthesized from a. niger mutant t21 was modified at 5' and 3' ends in order to clone it into yeast shuttle plasmid yfd18 and to cause fusion between cdna and the leader region of the yeast-mating pheromone alpha-factor. the modified cdna was then inserted into yfd18 at hindiii site. saccharomyces cerevisiae y33 was transformed with the resultant recombinant plasmid yfd18hh6. analysis of transformants including halo formation on starch medium plate, sds-page of culture filtrati ... | 1994 | 7893936 |
| development of a mutant strain of aspergillus niger and optimization of some physical factors for improved calcium gluconate production. | in the course of mutation studies of aspergillus niger strain ab with ethylene imine (1:4000), a mutant a. niger ab 501, produced greater amount of calcium gluconate in the culture broth (88.0 g/lit) as against the parent strain (36.0 g/lit) by the surface culture method of fermentation. this mutant was then exposed to uv-rays and a mutant, a.niger ab 1801, was found to produce high calcium gluconate in the culture broth (120 g/lit). the optimum cultural conditions for the production of calcium ... | 1994 | 7896318 |
| cutaneous infection with rhizopus oryzae and aspergillus niger following bone marrow transplantation. | we describe a case of mixed rhizopus oryzae and aspergillus niger infection in a 38 year-old woman who had undergone allogeneic bone marrow transplantation for multiple myeloma. the fungi were isolated from a necrotic ulcer under a plaster cast stabilizing a pathological fracture of the left humerus. we emphasize the necessity for frequent inspection of any covered area of skin and the use of sterile dressings as far as possible in neutropenic patients. | 1993 | 7907626 |
| identification and cloning of a second phytase gene (phyb) from aspergillus niger (ficuum). | an aspergillus niger (ficuum) genomic dna lambda embl3 library was probed with a 354-bp dna fragment obtained by polymerase chain reaction of a. niger dna with oligonucleotides based on partial amino acid sequence of a ph 2.5 optimum acid phosphatase. a clone containing a 1605 bp segment (phyb) encoding the 479 amino acid enzyme was isolated and found to contain four exons. global alignment revealed 23.5% homology to aspergillus niger phytase (phya); four regions of extensive homology were ident ... | 1993 | 7916610 |
| aspergillus niger as an unusual cause of scleritis and endophthalmitis. | | 1994 | 7918276 |
| mitochondrial dna restriction fragment length polymorphisms in field isolates of the aspergillus niger aggregate. | the mitochondrial dnas (mtdnas) and the ribosomal repeat unit (ribosomal dna, rdna) of black aspergillus isolates collected in various parts of the world were examined. wide-ranging mtdna variation was observed in natural populations of the aspergillus niger aggregate. most isolates were classifiable as a. niger or aspergillus tubingensis according to their rdna and mtdna patterns. the mtdna variation was distributed unevenly in the populations studied. the mtdnas of most of the isolates collect ... | 1994 | 7922884 |
| superoxide anion production in response to bacterial lipopolysaccharide and fungal spores implicated in organic dust toxic syndrome. | high amounts of fungal spores, bacteria, and bacterial endotoxin have been found in dust associated with the poorly characterized syndrome, organic dust toxic syndrome (odts). as part of an ongoing investigation to determine the etiopathogenesis for odts, this study has focused on activation of guinea pig bronchial alveolar lavage (bal) cells as evidenced by the production of superoxide anion in response to fungal spores and lipopolysaccharide (lps). fungal spores from aspergillus candidus, aspe ... | 1994 | 7925197 |
| thermodynamics of ligand binding to the starch-binding domain of glucoamylase from aspergillus niger. | the thermodynamics of ligand binding to the starch-binding domain (sbd) of glucoamylase from aspergillus niger has been studied using titration calorimetry. the ligand binding was studied both with the sbd fragment as well as glucoamylase g1 which contains both a catalytic domain and sbd. the ligands were beta-cyclodextrin and three thiopanose analogues [panose = alpha-d-glcp-(1-->6)-alpha-d-glcp-(1-->4)-d-glcp] each including an alpha-(1-->6) thioglycosidic linkage at the non-reducing end. beta ... | 1994 | 7925430 |
| general primer-mediated pcr for detection of aspergillus species. | a pcr assay was developed for the diagnosis of invasive aspergillosis in immunocompromised patients. for this purpose, the complete nucleotide sequences of the genes encoding the 18s rrna of aspergillus nidulans, aspergillus terreus, aspergillus niger, and aspergillus flavus were elucidated and aligned to the sequences of aspergillus fumigatus and other clinically relevant prokaryotic and eukaryotic microorganisms. genus-specific sequences could be identified in the v7 to v9 region of 18s rrna. ... | 1994 | 7929762 |
| crystallization and preliminary crystallographic characterization of endo-polygalacturonase ii from aspergillus niger. | the endo-polygalacturonase ii from aspergillus niger has been crystallized from an ammonium sulfate solution by the hanging drop method. the crystals belong to the monoclinic space group p2(1), with cell dimensions a = 69.6 a, b = 152.6 a, c = 74.0 a and beta = 91.2 degrees with four molecules per asymmetric unit. the crystals diffract to at least 2.8 a resolution and are suitable for x-ray analysis. | 1994 | 7932761 |
| the catr gene encoding a catalase from aspergillus niger: primary structure and elevated expression through increased gene copy number and use of a strong promoter. | synthetic oligonucleotide probes based on amino acid sequence data were used to identify and clone cdna sequences encoding a catalase (catalase-r) of aspergillus niger. one cdna clone was subsequently used to isolate the corresponding genomic dna sequences (designated catr). nucleotide sequence analysis of both genomic and cdna clones suggested that the catr coding region consists of five exons interrupted by four small introns. the deduced amino acid sequence of catalase-r spans 730 residues wh ... | 1993 | 7934925 |
| a study of the alkaline proteases secreted by different aspergillus species. | strains from several species of aspergillus were grown in the presence of soluble collagen, and the major secreted proteins present in the culture fluid were examined for proteolytic activity. the possibility of relatedness among the alkaline proteases secreted by aspergillus was studied by probing extracts from the various species with polyclonal antisera raised to the isolated alkaline proteases of a. fumigatus and a. oryzae. the pathogenic species a. flavus, a. terreus and a. nidulans hydroly ... | 1993 | 7935565 |
| site-directed mutagenesis of the catalytic base glutamic acid 400 in glucoamylase from aspergillus niger and of tyrosine 48 and glutamine 401, both hydrogen-bonded to the gamma-carboxylate group of glutamic acid 400. | replacement of the catalytic base glu400 by glutamine in glucoamylase from aspergillus niger affects both substrates ground-state binding and transition-state stabilization. compared to those of the wild-type enzyme, km values for maltose and maltoheptaose are 12- and 3-fold higher for the glu400-->gln mutant, with kcat values 35- and 60-fold lower, respectively, for the same substrates. this unusually high residual activity for a glycosylase mutant at a putative catalytic group is tentatively e ... | 1994 | 7947792 |
| transcriptional and post-transcriptional events affect the production of secreted hen egg white lysozyme by aspergillus niger. | the relationship between heterologous gene copy number, mrna and secreted protein yields has been studied in aspergillus niger transformants containing either the hen egg-white lysozyme (hewl) cdna gene or a glucoamylase-hewl gene fusion (incorporating the a. niger glaa gene). the results support a direct relationship between hewl gene copy number, mrna and secreted hewl protein levels at low (< 25) copy numbers. high protein yields are associated with multiple copies of the recombinant gene at ... | 1994 | 7951332 |
| adaptation of aspergillus niger to several antifungal agents. | adaptation of aspergillus niger to short-term stress induced by three antifungal agents [amphotericin b (amph), miconazole (mcz), and ketoconazole (kcz)] was observed and evaluated quantitatively using individual hyphae. spores were inoculated onto a poly-l-lysine-coated glass plate making up the base of a culture vessel. potato dextrose broth (pdb) was added and the vessel incubated for 24 h at 28 degrees c. the growth rate of an arbitrarily selected test hypha was measured automatically. expos ... | 1994 | 7952192 |
| active-site covalent modifications of quinoprotein amine oxidases from aspergillus niger. evidence for binding of the mechanism-based inhibitor, 1,4-diamino-2-butyne, to residue lys356 involved in the catalytic cycle. | interactions of two distinct quinoprotein amine oxidases from aspergillus niger, ao-i and ao-ii, with active-site covalent modifiers have been investigated. both enzymes are inhibited similarly by phenylhydrazine or p-nitrophenylhydrazine, forming an orange schiff base with a carbonyl group of topaquinone cofactor. modification of histidyl and tyrosyl residues by diethylpyrocarbonate and sulfhydryl groups by 5,5'-dithio-bis-(2-nitrobenzoic acid) and 4-chloro-7-nitrobenzo-2-oxa-1,3-diazole have b ... | 1994 | 7957232 |
| wf11899a, b and c, novel antifungal lipopeptides. ii. biological properties. | wf11899a, b and c, novel water-soluble lipopeptides related to the echinocandins, possess potent anti-candida activities. the ic50s of the compounds against four clinical isolates of candida albicans ranged from 0.004 to 0.03 microgram/ml by microbroth dilution assay. these compounds mildly suppressed the growth of aspergillus fumigatus and a. niger. wf11899a, b and c showed a potent in vivo anti-candida activity. particularly, wf11899a was superior to cilofungin, and equal to fluconazole. 1,3-b ... | 1994 | 7961157 |