Publications

resonance raman spectroscopic evidence for an anionic flavin semiquinone in bovine liver monoamine oxidase.	the flavoprotein monoamine oxidase b (mao b) from bovine liver, as isolated, has an unusual additional absorption band at 412 nm, which is similar to the absorption of its anionic flavin semiquinone form, (fl.-), and other typical (fl.-) flavoproteins. denaturation of the enzyme results in the elimination of this anomalous absorption. the resonance raman (rr) spectrum of mao b as isolated is virtually identical to that of its dithionite-reduced (fl.-) form. both spectra show features similar to ...	1993	8424650
functional roles of the invariant aspartic acid 55, tyrosine 306, and aspartic acid 309 in glucoamylase from aspergillus awamori studied by mutagenesis.	three mutants, asp55-gly, tyr306-->phe, and asp309-->asn, of aspergillus awamori glucoamylase (identical to aspergillus niger glucoamylase) were constructed to elucidate the roles of two conserved regions within fungal glucoamylases. kinetic studies indicate that both of these regions are closely associated with activity. the asp55-->gly mutation decreases the kcat approximately 200 times toward maltose and isomaltose, while km values remain similar to the wild-type. this localizes asp55 to subs ...	1993	8424940
induction of extracellular arabinases on monomeric substrates in aspergillus niger.	the induction of extracellular arabinases by pentose sugars and polyols generated by the metabolic pathway of l-arabinose and d-xylose catabolism in aspergillus niger was investigated. induction occurred with l-arabinose and l-arabitol but not with d-xylose or xylitol. l-arabitol in particular was found to be a good inducer for alpha-l-arabinofuranosidase and endo-arabinase activities. western blotting analysis showed both alpha-l-arabinofuranosidase a and b to be present. no induction was obser ...	1993	8427548
cloning, characterization, and use in strain improvement of the cephalosporium acremonium gene cefg encoding acetyl transferase.	a long open reading frame (orf) closely linked to the cephalosporium acremonium gene cefef was identified by dna sequencing. the cefef gene encodes the enzyme involved in cephalosporin c (cpc) biosynthesis known as expandase/hydroxylase. complementation of a c. acremonium cefg mutant, as well as expression of the gene in aspergillus niger, showed this orf to be the cefg gene, encoding cephalosporin c acetyltransferase, which catalyzes the last step in cpc biosynthesis. analysis of transformants ...	1993	8428381
genetic maps of eight linkage groups of aspergillus niger based on mitotic mapping.	this paper provides a genetic map of aspergillus niger. at present 84 markers have been assigned to eight linkage groups. the chromosomal location of 60 markers is presented in this paper. the allocation of markers is based on recombination due to mitotic crossing over. various methods for selection and analysis of homozygous recombinants were applied, using colour, auxotrophic and resistance markers. in addition, transformants carrying the heterologous aspergillus nidulans gene coding for aceta ...	1993	8428383
refined structure for the complex of 1-deoxynojirimycin with glucoamylase from aspergillus awamori var. x100 to 2.4-a resolution.	the three-dimensional structure of the complex of 1-deoxynojirimycin with glucoamylase ii-(471) from aspergillus awamori var. x100 has been determined to 2.4-a resolution. the model includes residues corresponding to residues 1-471 of glucoamylase i from aspergillus niger, two molecules of bound 1-deoxynojirimycin and 605 sites for water molecules. the crystallographic r factor from refinement is 0.119, and the root-mean-squared deviation in bond distances is 0.012 a. the inhibitor complex confi ...	1993	8431441
functional roles and subsite locations of leu177, trp178 and asn182 of aspergillus awamori glucoamylase determined by site-directed mutagenesis.	fungal glucoamylases contain four conserved regions. one region from the aspergillus niger enzyme contains three key carboxylic acid residues, the general acid catalytic group, glu179, along with asp176 and glu180. three site-directed mutations, leu177-->his, trp178-->arg and asn182-->ala, were constructed near these acidic groups to reveal the function of other conserved residues in this region. leu177 and trp178 are strictly conserved among fungal glucoamylases, while an amide, predominantly a ...	1993	8433972
characterization of the gene encoding alpha-sarcin, a ribosome-inactivating protein secreted by aspergillus giganteus.	the filamentous fungus, aspergillus giganteus, produces the extracellular ribosome-inactivating protein, alpha-sarcin (sar). the structural gene (sar) encoding sar was isolated and characterized by sequence analysis and expression in aspergillus niger. it codes for a precursor of 177 amino acids containing a secretion signal sequence that is absent in the mature protein. the nucleotide sequence contains several typical features of fungal genes, including a short intron of 65 bp. the transcriptio ...	1993	8444347
effect of formulation ph and storage temperatures on the preservative efficacy of some gases used as propellants in cosmetic aerosols.	the effects of changes in formulation ph and storage temperature on the preservative activities of some aerosol propellants--butane, carbon dioxide, dimethylether and their combinations were investigated. a preservative challenge test method was used to determine the survival rates of escherichia coli, pseudomonas aeruginosa, staphylococcus aureus, candida albicans and aspergillus niger at formulation ph levels 5.80, 7.28 and 8.10 and storage temperatures of 20 degrees, 30 degrees and 40 degrees ...	1993	8444651
cloning and characterisation of pepc, a gene encoding a serine protease from aspergillus niger.	we have cloned a gene, pepc, encoding a serine proteinase, pepc, from aspergillus niger by screening a phage lambda genomic dna library with a gene (prb1) from saccharomyces cerevisiae which codes for proteinase yscb. the nucleotide (nt) sequence of pepc revealed that the gene is composed of two exons of 369 nt and 1230 nt separated by a single 70-nt intron. the deduced protein of 533 amino acids (aa) has a putative signal sequence for transport into the endoplasmic reticulum. based on the exten ...	1993	8449413
isolation and characterization of the aspergillus oryzae gene encoding aspergillopepsin o.	we have cloned and determined the nucleotide sequence of a genomic dna segment from aspergillus oryzae which contains pepo, the gene encoding the aspartic proteinase, aspergillopepsin o (pepo). the organization of pepo is strikingly similar to that of pepa from a. niger var. awamori (previously called a. awamori) in that both are composed of four exons and three introns with virtually identical lengths, and the positions of the introns are exactly conserved. from the deduced amino acid (aa) sequ ...	1993	8462873
release of volatile branched-chain and other fatty acids from ruminant milk fats by various lipases.	bovine, ovine, and caprine milk fats were treated with pregastric lipases (kid goat, calf, and lamb), microbial lipases (candida cylindracea, c. cylindracea ay30, aspergillus niger apf12, rhizopus arrhizus, penicillium roqueforti r10, and mucor zavanicus map 10), porcine pancreatic lipase, or milk lipase. all three pregastric lipases preferentially hydrolyzed volatile branched-chain and short n-chain fatty acids from each milk fat. pregastric lipases also released a relatively low proportion of ...	1993	8463483
[placental aspergillosis: myth or reality? apropos of a case with fetal death in utero].	the authors report an original case-history of massive aspergillosis of the placenta that occurred in a 24 year old primigravida who had had no previous history or clinical changes in pregnancy. it caused fetal death in utero with retention and maceration of the fetus. macroscopic examination showed that the left lip was cleft and that the placenta was studded with isolated confluent diffuse whitish granulations. histologic examination made us think that these appearances were those of aspergill ...	1993	8463573
microbial reduction of aromatic carboxylic acids.	several benzoic, cinnamic and phenylacetic acid derivatives were screened with 20 micro-organisms, mainly fungi, for the reduction of their carboxylic function. for all organisms several compounds were reduced in fairly good yields up to 80% to the corresponding alcohol. no general rule could be established, concerning the substitution pattern, as to which compounds were transformed to the alcohol. generally the reactions were accomplished within 48-70 h. only minor, if any, side products were d ...	1993	8471102
subsite affinities of aspergillus niger glucoamylase ii determined with p-nitrophenylmaltooligosaccharides.	kinetic parameters were obtained for glucoamylase catalysed hydrolysis of substrates of an alpha-(1,4)-maltooligosaccharide series and of a p-nitro-phenyl-alpha-maltooligosaccharide series. p-nitrophenyl substrates of chain length 11 and 17 were synthesized in 97% and 95% purity, respectively, to test the significance of binding at remote subsites. the affinities of the subsites > 4 are demonstrated to be insignificant. the subsite binding contributions for d-glucopyranosyl and for p-nitrophenyl ...	1993	8471180
a truncated glucoamylase gene fusion for heterologous protein secretion from aspergillus niger.	the secreted yield of hen egg-white lysozyme (hewl) from the filamentous fungus aspergillus niger was increased 10-20-fold by constructing a novel gene fusion. the cdna sequence encoding mature hewl was fused in frame to part of the native a. niger gene encoding glucoamylase (glaa), separated by a proteolytic cleavage site for in vivo processing. using this construct, peak secreted hewl yields of 1 g/l were obtained in a. niger shake flask cultures compared to about 50 mg/l when using an express ...	1993	8472909
comparison of several new chromogenic galactosides as substrates for various beta-d-galactosidases.	the kinetic characteristics of beta-galactosidases from bovine liver and testes, escherichia coli, aspergillus niger and jack bean were studied using five newly-developed colorimetric substrates. all the chromophores released by enzyme hydrolysis had high extinction coefficients in the visible region of the spectrum. varying amounts of substrate inhibition were found with each of these substrates (vbztm-gal, vlm-gal, vlpr-gal, vqm-gal and vqpr-gal), but this was not a significant problem if the ...	1993	8476929
mycoflora and mycotoxin of hazelnut (corylus avellana l.) and walnut (juglans regia l.) seeds in egypt.	fifty-one species and 3 varieties appertaining to 20 genera were collected from 20 samples of each of hazelnut and walnut seeds on glucose- and 40% (w/v) sucrose-czapek's agar at 25 degrees c and 45 degrees c with the most common mesophiles were aspergillus flavus, a. fumigatus, a. niger, cladosporium cladosporioides, c. herbarum, penicillium chrysogenum, p. citrinum and p. oxalicum. fusarium (represented by f. equiseti, f. moniliforme and f. oxysporum) was recovered from walnut seeds in moderat ...	1993	8480455
production of high concentrations of ethanol from inulin by simultaneous saccharification and fermentation using aspergillus niger and saccharomyces cerevisiae.	pure nonhydrolyzed inulin was directly converted to ethanol in a simultaneous saccharification and fermentation process. an inulinase-hyperproducing mutant, aspergillus niger 817, was grown in a submerged culture at 30 degrees c for 5 days. the inulin-digestive liquid culture (150 ml) was supplemented with 45 g of inulin, 0.45 g of (nh4)2so4, and 0.15 g of kh2po4. the medium (ph 5.0) was inoculated with an ethanol-tolerant strain, saccharomyces cerevisiae 1200, and fermentation was conducted at ...	1993	8481000
topical treatment of pulmonary aspergilloma by antifungals. relationship between duration of the disease and efficacy of therapy.	twelve patients with aspergilloma were treated with intracavitary or endobronchial administration of antifungals. patients with successful therapy had significantly shorter mean duration of the disease course (3.6 months) than the less effective group (44.4 months, p < 0.01). minimal inhibitory concentrations of antifungal agents against isolated strains of aspergilli were considerably lower than estimated intracavitary concentrations of the antifungals. a pathologic examination suggested that t ...	1993	8486021
antimicrobial activity determined in strains of bacillus circulans cluster.	wild-type strains of the genus bacillus were screened for antimicrobial activity. two strains exhibited antimicrobial activity against micrococcus luteus and were identified as bacillus polymyxa mir-23 and bacillus circulans mir-13. bacillus polymyxa mir-23 was active against escherichia coli, pseudomonas aeruginosa and aspergillus niger, whereas bacillus circulans mir-13 did not show activity against these microorganisms. bacillus subtilis atcc 6633 and b. polymyxa atcc 10401 were used as stand ...	1993	8500778
production, purification and characterization of the catalytic domain of glucoamylase from aspergillus niger.	the catalytic domain of glucoamylases g1 and g2 from aspergillus niger is produced in vitro in high yield by limited proteolysis using either subtilisin novo or subtilisin carlsberg. purification by affinity chromatography on an acarbose-sepharose column followed by ion-exchange chromatography on hiload q-sepharose leads to separation of a number of structurally closely related forms of domain. the cleavage occurs primarily between val-470 and ala-471 as indicated by c-terminal sequencing, where ...	1993	8503847
effect of processing on the mycoflora and aflatoxin b1 level of a cassava-based product.	cassava bread was prepared by pre-gelling, battering and baking cassava flour to which were added, in moderate amounts, sugar, yeast solution and edible oil. baking was at 215 degrees c for 40 min. no mould was isolated from the cassava bread and the mean value of aflatoxin b1 (afb1) for the three subsamples of cassava bread was 0.03 microgram/kg. the cassava tuber (manihot esculenta crantz), which was used for the production of cassava bread had an initial afb1 level of 1.91 micrograms/kg and t ...	1993	8506233
glucoamylase overexpression in aspergillus niger: molecular genetic analysis of strains containing multiple copies of the glaa gene.	a strategy, based on the usage of the amds selection marker and a cosmid vector containing four copies of the glucoamylase gene (glaa), was developed to obtain glucoamylase (gla)-overproducing a. niger strains. with this strategy, fungal strains carrying up to 200 copies of the glaa gene could be isolated at a relatively high frequency. in each transformant analysed, integration occurred in a single chromosome. a significant increase in the extracellular gla production was observed in most of th ...	1993	8513339
purification, characterization, and lytic activity against naegleria fowleri of two amoebicins produced by bacillus licheniformis a12.	bacillus licheniformis a12 produces two amoebolytic substances (amoebicins a12-a and a12-b) in liquid media during sporulation. both substances have been purified and characterized. they are heat- and protease-resistant peptides containing aspartic acid, glutamic acid, serine, proline, and tyrosine in a molar ratio of 5:2:2:2:2. no fatty acids or carbohydrates have been detected. their molecular weight is 1,430. purified amoebicins a12-a and a12-b exhibit amoebolytic action against naegleria fow ...	1993	8517742
synthesis, cloning and sequencing of glucoamylase cdna from aspergillus niger mutant t21.	poly(a)+ rna was isolated from aspergillus niger t21, a glucoamylase overproducing strain and was used as template to synthesize double stranded cdna. a cdna library was then constructed. the e. coli transformants were screened for the glucoamylase cdna by in situ colony hybridization with p-labeled fragment of glucoamylase gene as probe. the positive rate was 1.6%. restriction analysis proved that 32% of the positive clones carried the inserts of 2.1 kb of full length glucoamylase cdna. sequenc ...	1993	8199326
antifungal activity of essential oil from artemisia afra jacq.	artemisia afra is indigenous to the eastern highlands of zimbabwe where it is used in folk medicine. hydro-distilled volatile oil from the aerial parts of the plant was tested for antifungal activity against 10 fungal species using the dry weight method. the results obtained showed that the essential oil exhibited significant activity against aspergillus ochraceus, candida albicans, alternaria alternata, geotrichum candidum, aspergillus niger, penicillium citrium and aspergillus parasiticus.	1993	8205606
filamentous fungi and mycotoxin detected in coconut.	fifty-nine species and one variety belonging to 25 genera of fungi were isolated from 25 coconut samples on glucose-czapek's (25 genera and 55 species + 1 variety) and dichloran-glycerol (8 genera and 32 species + 1 variety) agar media at 28 degrees c. the common fungi on both media used were aspergillus flavus, a. niger, penicillium chrysogenum and cladosporium cladosporioides. on glucose-czapek's agar, a. flavus var. columnaris, p. oxalicum, alternaria alternata, rhizopus stolonifer and tricho ...	1993	8212938
survey of airborne culturable and non-culturable fungi at different sites in delhi metropolis.	a two year aerobiological survey for culturable and non-culturable fungi was conducted at human height at five different sites in delhi metropolis. burkard personal volumetric sampler for petriplates and slide exposures were used for sampling the air. with simultaneous petriplate and slide exposure a total of 98 fungal forms were recorded. cladosporium contributed for 25-40% of total airborne fungi followed by ustilago (smuts) (24%) aspergillus flavus (10-13%), alternaria (11%) and a. niger (8%) ...	1993	8216555
heat resistance of fungi from soil.	the survival of fungi from soil samples has been investigated after exposure to temperatures of 60, 70, 80 and 90 degrees c in sabouraud agar. the least resistant fungi surviving 60 degrees c for 60 min were the aspergillus (a.) niger group, chaetomium spp, penicillium spp, and scytalidium lignicola. none of these survived 70 degrees c for 10 min. the next group surviving 70 degrees c for 60 min included the a. glaucus group, byssochlamys nivea, dichotomomyces cejpii, gelasinospora spp, rhizocto ...	1993	8217516
lipolytic activity and degradation of rapeseed oil and rapeseed by spoilage fungi.	aspergillus, eurotium and penicillium spp. from rapeseed were able to grow and produce lipases over a range of water activities (aw) at both 15 and 25 degrees c on tributyrin agar. the ability to produce lipases was not directly related to growth rate. the clearing zone: growth rate ratios gave lipase indices which varied markedly between test fungi and with aw. the fungi with the highest indices were aspergillus candidus and aspergillus versicolor and penicillium expansum and penicillium hordei ...	1993	8217518
heterologous protein secretion directed by a repressible acid phosphatase system of aspergillus niger.	a new expression-secretion system of aspergillus niger which directs the secretion of heterologous proteins is described. the promoter and signal peptide-encoding region of the phosphate-repressible apha gene of a. niger, when fused to the coding region of the human interferon alpha 2 (hifn alpha 2)-encoding gene (hifn alpha 2), drives the expression of this gene and the secretion of the hifn alpha 2 protein. synthesis of hifn alpha 2 in either a. niger or a. nidulans transformants carrying thes ...	1993	8224863
the cloning and sequencing of the genes encoding phytase (phy) and ph 2.5-optimum acid phosphatase (aph) from aspergillus niger var. awamori.	the genes encoding phytase (ec 3.1.3.8) and ph 2.5-optimum acid phosphatase (ec 3.1.3.2) have been cloned and sequenced from aspergillus niger var. awamori. the translated nucleotide sequences yielded polypeptides of 467 and 479 amino acids (aa) for phytase and acid phosphatase, respectively. the genes were isolated using oligodeoxyribonucleotide probes based on the aa sequences of the purified proteins. recombinant a. niger var. awamori strains carrying additional copies of the gene sequences d ...	1993	8224894
survey of mycoflora and mycotoxins of some dried fruits in egypt.	fifty-five species and two varieties appertaing to 23 genera were collected and identified from 4 samples of dried fig and 3 dried samples of each of apricot, plum and raisin. forty-nine species and two varieties belonging to 20 genera were isolated on 1% glucose-czapek's while 31 species and one variety belonging to 16 genera were isolated on 40% sucrose-czapek's agar medium at 28 +/- 2 degrees c. penicillium, aspergillus and cladosporium were the common genera on the two types of media used. a ...	1993	8229671
arabinan degrading enzymes from aspergillus nidulans: induction and purification.	the presence in aspergillus nidulans of two enzymes related to the aspergillus niger endo-arabinase and alpha-l-arabinofuranosidase b has been established using antibodies against the purified a. niger enzymes. moreover, the absence of an equivalent in a. nidulans to the alpha-l-arabinofuranosidase a of a. niger has been confirmed both at the protein and at the dna level. both a. nidulans arabinases have been purified and physico-chemically and kinetically characterized. they have a much higher ...	1993	8243977
influence of medium components and metabolic inhibitors on citric acid production by penicillium simplicissimum.	penicillium simplicissimum excreted more than 100 mmol citric acid l-1 [2.9 mmol (g dry wt)-1; 9 d] if an industrial filter dust (> 50% zno) providing a high extracellular buffering capacity was present in the medium. a similar specific [2 mmol (g dry wt)-1], but lower absolute (26 mmol l-1), citric acid excretion occurred in the absence of an extracellular buffer and if amino acids or urea were used as nitrogen source. p. simplicissimum excreted no citric acid under conditions where aspergillus ...	1993	8245837
structural analysis of tamarind seed xyloglucan oligosaccharides using beta-galactosidase digestion and spectroscopic methods.	the borohydride-reduced forms (oligoglycosyl alditols) of two isomeric octasaccharides (glc4xyl3gal) that are released from xyloglucans of various plant species upon treatment with a fungal endo-(1-->4)-beta-glucanase were isolated and structurally characterized. a mixture of oligosaccharides that is released from tamarind seed xyloglucan by the endo-(1-->4)-beta- glucanase was digested with a commercially available beta-galactosidase (aspergillus niger). the beta-galactosidase selectively hydro ...	1993	8252539
isoelectric focusing in a multicompartment electrolyzer with zwitterionic membranes, exemplified by purification of glucoamylase.	a highly purified preparation of glucoamylase g1 from aspergillus niger was found, by isoelectric focusing in immobilized ph gradients, to contain a major form with a pi of 3.50 and a number of minor, more acidic and more basic contaminants. the major isoform was purified to homogeneity by recycling isoelectric focusing in a multicompartment electrolyzer, by confining this form in between two zwitterionic membranes, with pi 3.49 at the anodic side and pi 3.52 at the cathodic side. recoveries wer ...	1993	8258640
biocidal effects and residual glutaraldehyde in cellulosic and synthetic polymers.	the amount of leachable glutaraldehyde from medical grade cuprophan 150pm (cellulose based) and an69s (a copolymer of acrylonitrile and sodium methallyl sulphonate) membranes, and polyproprene plates following 72 hr immersion in 2% alkaline glutaraldehyde was determined. after rinsing the materials for 30 minutes in distilled water at 37 degrees c, the mean concentration of leachable glutaraldehyde from cuprophan 150 pm (8. 60 +/- 0.55 micrograms/g) was significantly greater than that from an69s ...	1993	8261949
spectroscopic study of the temperature-dependent conformation of glucoamylase.	vibrational circular dichroism, electronic circular dichroism and infrared absorption with fourier self-deconvolution have been used for a conformational study of the small form, g2, of glucoamylase, 1,4-alpha-d-glucan glucohydrolase from aspergillus niger (ec 3.2.1.3) in aqueous solution. from the temperature dependence of spectra measured from 25 degrees c to 60 degrees c it was seen that the helical content is relatively constant to 50 degrees c and then sharply decreases by a factor of more ...	1993	8268213
survey of mycoflora and mycotoxins in egyptian soybean seeds.	after four months in commercial storage, 100 soybean samples from different places of egyptian governorates were assayed for filamentous fungal growth at two incubation temperatures (28 and 45 degrees c). 73 species and 8 varieties belonging to 32 genera were isolated by the dilution plate method. at 28 degrees c, the common species were aspergillus flavus, a. fumigatus, a. niger and a. alutaceus, followed by a. terreus, penicillium chrysogenum, p. citrinum, mucor hiemalis, m. racemosus, emerice ...	1993	8271157
a new crystal form of proteinase a, a non-pepsin-type acid proteinase from aspergillus niger var. macrosporus.	proteinase a from aspergillus niger var. macrosporus is a non-pepsin-type acid proteinase, whose catalytic residues and mechanism remain to be elucidated. a new form of proteinase a crystals more suitable for crystallography than that obtained previously was prepared from an ammonium sulfate solution at ph 3.5 by the hanging-drop vapor diffusion method. the space group of the crystals was p2(1)2(1)2(1), with unit cell dimensions of a = 69.75 +/- 0.06 a, b = 87.55 +/- 0.05 a, and c = 60.83 +/- 0. ...	1993	8276753
purification and characterization of glucose-6-phosphate dehydrogenase from aspergillus niger and aspergillus nidulans.	glucose-6-phosphate dehydrogenase (g6pd; d-glucose 6-phosphate:nadp+ oxidoreductase, ec 1.1.1.49) has been purified from aspergillus nidulans and aspergillus niger by a combination of affinity and anion exchange chromatography. a 500-1000-fold purification was obtained and the final enzyme preparations were shown to be pure but not homogeneous. for both fungi the purified enzyme preparation gave two bands on native and denaturing gels. the catalytically active form is a multimer. the molecular m ...	1993	8277259
growth and product formation in chemostat and recycling cultures by aspergillus niger n402 and a glucoamylase overproducing transformant, provided with multiple copies of the glaa gene.	continuous and recycling cultures were carried out with aspergillus niger n402 wild-type and a glucoamylase overproducing transformant to investigate growth and product formation characteristics. in shake flask cultures, the amount of glucoamylase produced by the transformant was about five times more than by the wild-type strain. in contrast with these results, a twofold overproduction was found in glucose-limited continuous cultures, while no overproduction was found under maltodextrin-limitat ...	1993	8277260
amylase activity of aspergillus strains--producers of organic acids.	the ability of fungi from genus aspergillus (producers of organic acids) to synthesize amylase enzymes (alpha-amylase and glucoamylase) was investigated. the productivity of the strains on czapek-dox agar and in liquid czapec-dox media with 3% soluble starch as a carbon source was established.	1993	8285132
kinetics of the gluconic acid biosynthesis by strain aspergillus niger 13-73.	the kinetics of gluconic acid biosynthesis of the strain aspergillus niger 13-73 by submerged cultivation in a medium containing 26% glucose was investigated. the maximum amount of the product was obtained at minimum biomass growth. the yield of the product compared to the theoretical one was 95% and the fermentation period was 42 hours. the results regarding the limitation theory are discussed.	1993	8285133
fermentation of lactose by yeast cells secreting recombinant fungal lactase.	strains of saccharomyces cerevisiae transformed with a yeast multicopy expression vector carrying the cdna for aspergillus niger secretory beta-galactosidase under the control of adh1 promoter and terminator were studied for their fermentation properties on lactose (v. kumar, s. ramakrishnan, t. t. teeri, j. k. c. knowles, and b. s. hartley, biotechnology 10:82-85, 1992). lactose was hydrolyzed extracellularly into glucose and galactose, and both sugars were utilized simultaneously. diauxic grow ...	1993	8285714
[microbiology of acute external otitis in our environment].	the paper deals with the review done by the aa. about the microbiology of 135 acute diffuse external otitis cases, treated at their department in one year term. in the series is emphasized the seasonal distribution, steadily uniform in the studied period, being the pseudomonas aeruginosa and candida albicans the paramount responsible for these otitis.	1993	8291664
supplementing corn-soybean meal diets with microbial phytase linearly improves phytate phosphorus utilization by weanling pigs.	two experiments were conducted with weanling pigs to determine the effectiveness of a dietary supplement of aspergillus niger phytase in improving the availability of phytate-p in corn-soybean meal diets without supplemental inorganic p. experiment 1 consisted of two p and ca balance trials and two feeding trials. twelve pigs (8.18 +/- .44 kg bw) were housed individually in stainless steel metabolism cages. six pigs received 750 phytase units (pu)/g of basal diet and the other six pigs received ...	1993	8294288
supplementing corn-soybean meal diets with microbial phytase maximizes phytate phosphorus utilization by weanling pigs.	two experiments were conducted with crossbred weanling pigs to determine the optimal dietary supplement of aspergillus niger phytase activity to a low-p, corn-soybean meal basal diet (bd). in exp. 1, 50 pigs (7.61 +/- .56 kg bw) received the bd supplemented with 750, 1,050, 1,250, or 1,350 phytase units (pu)/g, or .21% p as mono-dibasic calcium phosphate (mdcap) for 4 wk. in exp. 2, 12 pigs (6.39 +/- .74 kg bw) were individually housed in metabolism cages and received bd, bd plus the optimal phy ...	1993	8294289
effects of 1,5-anhydro-d-fructose on selected glucose-metabolizing enzymes.	it was verified, by n.m.r. and fast-atom-bombardment-m.s. studies, that the c-2 position of 1,5-anhydro-d-fructose, which was prepared by the reaction of immobilized glucose 2-oxidase from coriolus versicolor (with 1,5-anhydro-d-glucitol), is hydrated to the acetal form in water. the effects of 1,5-anhydro-d-fructose on several glucose-metabolizing enzymes were compared with those of 1,5-anhydro-d-glucitol. glucose 1-oxidase from aspergillus niger was inhibited by 1,5-anhydro-d-fructose (ki 6.6 ...	1993	8297506
purification of endo-polygalacturonase by affinity precipitation using alginate.	the precipitation of alginate by ca2+ at ph 3.8 was found to occur concomitantly with the precipitation of endo-polygalacturonase from aspergillus niger. under optimum conditions, 92% of the enzyme activity was precipitated. the enzyme could be recovered from the precipitate by washing with 0.5 m nacl/0.2 m ca2+. all the precipitated endo-polygalacturonase activity could be recovered in this way. the enzyme thus obtained was purified 10-fold. a comparison of sds/page gel patterns of the crude pr ...	1993	8297509
induction of glucose oxidase, catalase, and lactonase in aspergillus niger.	the induction of glucose oxidase, catalase, and lactonase activities was studied both in wild-type and in glucose oxidase regulatory and structural mutants of aspergillus niger. the structural gene for glucose oxidase was isolated and used for northern analysis and in transformation experiments using various gox mutations. wild-type phenotype could be restored in the glucose oxidase-negative mutant (goxc) by transformation with the structural gene. we conclude, therefore, that the goxc marker wh ...	1993	8299156
cloning and characterization of the abfb gene coding for the major alpha-l-arabinofuranosidase (abf b) of aspergillus niger.	based on amino-acid sequence data from aspergillus niger alpha-l-arabinofuranosidase b (abf b), and cyanogen bromide fragments derived thereof, deoxyoligonucleotide mixtures were designed to be employed as primers in a polymerase chain reaction (pcr) on a. niger genomic dna. this resulted in amplification of three related pcr products. the abfb gene encoding abf b was isolated from a genomic library using such an amplification product as a probe. a 5.1-kb bamhi fragment was subcloned to result i ...	1993	8299175
a study of the use of rapid methods for preservative efficacy testing of pharmaceuticals and cosmetics.	three rapid microbiological methods, impedance, the direct epifluorescence technique (deft-mem) and atp bioluminescence (atp-b) were evaluated for their applicability to preservative efficacy testing (pet) of pharmaceuticals and cosmetics. a good correlation between rapid method response and total colony counts was obtained for untreated suspensions of staphylococcus aureus, pseudomonas aeruginosa and candida albicans with all three methods but, for aspergillus niger, with impedance only. for ch ...	1993	8300446
evaluation and control of worker exposure to fungi in a beet sugar refinery.	a study of worker exposure to airborne fungi was undertaken in a sugar beet refinery to evaluate the level of exposure and to determine if controls could be implemented that would lower these exposures. a previous study at this refinery identified one worker who reacted on challenge testing to the moldy but not the fresh sugar beet pulp, had specific immunoglobulin g to aspergillus niger, and specific immunoglobulin e to aspergillus. also, two employees were diagnosed with occupational asthma. i ...	1993	8304278
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
the normal mycoflora of commodities from thailand. 1. nuts and oilseeds.	a comprehensive study was carried out of the fungi occurring in commodities normally traded in thailand. samples of major commodities were obtained from farmers' stocks and middlemen in major producing areas throughout the country. retail samples were obtained from outlets in and around bankok. samples were divided into two portions, one being examined in bangkok, and the second in sydney. after surface disinfection, fungi were enumerated by direct plating on dichloran rose bengal chloramphenico ...	1993	8110599
enhancement of zinc utilization from phytate-rich soy protein isolate by microbial phytase.	a study with three groups, each with 11 male, individually housed albino rats (initial average weight = 50 g) was undertaken to examine the effect of microbial phytase (added to a diet containing phytate) on the availability of zinc. the rats were fed diets on the basis of soy protein isolate and corn starch over a 3-week period. all diets contained 15-16 mg zn/kg diet and 0.40% pa. thus, molar pa:zn-ratios of 26:1 were obtained. group i (control) was fed the phytase-free basal diet. in groups i ...	1993	8128752
antifungal activities of crude extracts of mitracarpus villosus (rubiaceae).	extracts of mitracarpus villosus leaves and inflorescences were investigated individually for in vitro antifungal activities by agar-diffusion and tube-dilution techniques. ethanolic extracts produced definite antifungal activities against trichophyton rubrum, microsporum gypseum, candida albicans, aspergillus niger and fusarium solani. the aqueous extracts and the glycerol vehicle control did not inhibit any of the fungi tested. the zones of inhibition produced by the ethanol extracts ranged fr ...	1993	8133654
[inhibition of growth of microscopic fungi with organic acids].	fungicidal effects of five selected organic acids (lactic, acetic, formic, oxalic, and propionic) in concentrations 3, 5, 10, 20 and 50 ml/l on nine selected species of moulds were tested. lactic and oxalic acids did not prove the satisfactory fungicidal activity in any of the chosen concentrations. the antifungal effect of the other three acids, manifested by the growth inhibition of the tested moulds is shown in tab. i and it can be expressed by sequence: propionic acid, formic acid, and aceti ...	1993	8122343
the influence of flow rate on biosensors based on redox enzymes incorporated in a redox polymer mounted in a thin-layer flow cell.	enzyme electrodes, based on redox enzymes immobilized in redox polymers at electrode surfaces, were mounted in a thin-layer flow cell. the catalytic currents at different flow rates and concentrations for a continuous flow of substrate solution were measured and compared with the peak currents for injections of a plug of substrate solution, under corresponding conditions. the catalytic steady-state current for continuous-flow measurements increased with increasing flow rate, i.e., with increasin ...	1993	8122787
hydrolysis of glycosylpyridinium ions by anomeric-configuration-inverting glycosidases.	the hydrolyses of five beta-d-xylopyranosylpyridinium ions by the beta-d-xylosidase of bacillus pumilus proceed with kcat values 10(8)-10(9)-fold larger than the rates of spontaneous hydrolysis of the same compounds. log(kcat) values correlate well with aglycon pk(a) [b1g(v) = -0.52, r = 0.99], whereas the correlation of log(kcat/km) is poor [r = 0.77; beta 1g(v/k) = approximately -0.6]. the (1-->3)-beta-d-glucanase of sporotrichum dimorphosporum hydrolyses 4-bromo-2-(beta-d-glucopyranosyl)isoqu ...	1993	8143292
in-vitro activity of the new triazole d0870 compared with amphotericin b and itraconazole against aspergillus spp.	the in-vitro activity of d0870, a new triazole, was compared with amphotericin b (amp b) and itraconazole (itz) against 40 aspergillus isolates, which included 25 isolates of aspergillus fumigatus, using a broth macro-dilution method at 37 degrees c. minimum inhibitory concentration (mic) and minimum fungicidal concentration (mfc) (killing of > or = 98%) were measured. for 40 isolates, geometric mean (gm) mic values and ranges were d0870 10.55 and 2-32, itz 2.26 and 0.5-64, amp b 2.42 and 1-64 m ...	1993	8144422
fungal flora and mycotoxins of six kinds of nut seeds for human consumption in saudi arabia.	a wide range of moulds representing several genera and species, was recorded in this study from 5 seed samples of each almond, cashew nut, chestnut, hazelnut, pistachio nut and walnut collected from different markets in ar' ar, saudi arabia. the total counts of fungi were widely fluctuated between 1960-7704 and 1948-7434 colonies/g dry seeds on glucose-czapek's and glycerol agar media at 28 degrees c, respectively, and represented twenty genera, 53 species and 2 varieties of fungi. the prevalent ...	1993	8159218
glutathione synthetase from the fission yeast. purification and its unique heteromeric subunit structure.	glutathione (gsh) synthetase (ec 6.3.2.3) was purified from the fission yeast schizosaccharomyces pombe l972h- and from the gsh synthetase deficient mutant mn101/pys41, which harbors a plasmid containing the gsh synthetase gene of the fission yeast. gsh synthetase is expressed at 10 times higher the amount in mn101/pys41 than in wild-type l972h-. the purified enzyme gave a single band on polyacrylamide gel electrophoresis in the absence of sodium dodecyl sulfate (native page). the molecular weig ...	1993	8192897
lipase production by aspergillus niger under various growth conditions using solid state fermentation.	ricinus seed litters were chosen as a cheap carbon source for lipase production by a. niger under solid state fermentation (ssf). maximum lipase production was achieved upon using an enriched (potassium citrate and casein) waste at ph 7.8 and 30 degrees c for 8 days incubation. nitrogen sources as nh4cl, nh4no3, (nh4)2so4, urea and amino acids repressed the lipolytic activity. the chloride salts of ba2+, co2+, cu2+, fe3+, hg2+, k+, mg2+, mn2+, na+ and sn2+ inhibited, while zn+2 did not affect li ...	1993	8172691
growth of three fungi on poultry fat or beef tallow.	aspergillus niger, geotrichum candidum and mucor miehei, when grown on a medium containing beef tallow or poultry fat for 5 days at 28°c, in roux bottles, shake-flasks or fermenters, synthesized from 0.4 to 3.2 g lipids/i. the degree of fat utilization varied from 15 to 70%. the type of fat in the medium, the species of fungi and its cultivation method all influenced the fatty acid composition of fats remaining in the medium, as well as the intracellular lipids of the fungi.	1993	24420293
antimycotic effect of fixed oils treated with herbal seeds on the growth of fungi causing otomycosis.	invitro antimycotic effect of the coconut, mustard, groundnut & soyabeen oils and the seeds of trigonella, ajwoin, mustard and garlic bulbs were mixed in the above oil samples to determine their effect on the spore germination of five pathogenic fungi i.e., aspergillus niger, a.flavus, absidia corymbifera, penicilium nigricans and candida albicans, isolated from otitic fungal infection of external ear (tympanic membrane) of human beings of different places. growth of these fungi was completely i ...	1993	22556643
sugarcane-pressmud as a novel substrate for production of citric acid by solid-state fermentation.	sugarcane-pressmud, a by-product of cane-sugar manufacture, was used as a substrate for production of citric acid by aspergillus niger cftri 30, in a solid-state fermentation system. of the 170 g of sugar supplied, 131 g were consumed, with a 79% yield of citric acid over 120 h. potassium ferrocyanide improved the conversion to about 88% and lowered the fermentation time by 24 h. enrichment with sugar and nh4no3 was essential to improve productivity. about 174 g citric acid/kg dry sugarcane-pres ...	1993	24420047
microbial leaching of lateritic nickel ore.	lateritic nickel ore from the sukinda mines, orissa, india, was leached using thiobacillus ferrooxidans, bacillus circulans, bacillus licheniformis and aspergillus niger at 5% (w/v) solid: liquid ratio for 5-20 days. maximum leaching of ni was achieved with b. circulans (85%) and aspergillus niger (92%) after 20 days. bacillus circulans showed significantly higher rate of leaching than the other organisms giving 80% ni extraction after 15 days. the importance and usefulness of heterotrophic orga ...	1993	24419960
methanol utilization by a strain of aspergillus niger: influence on the synthesis and activity of pectinases.	during the production of pectinases by a strain of aspergillus niger isolated from rotten lemons, methanol was liberated into the medium due to the cleavage of the pectin molecule used as the carbon source. the methanol was subsequently consumed by the microorganism but neither the synthesis nor the activity of pectinesterase and polygalacturonase was affected. although not studied in detail, the mechanism involved in the utilization of methanol is similar to that described for methylotrophic ye ...	1993	24419947
structure of malformin a, a phytotoxic metabolite produced by aspergillus niger.	malformins-produced by aspergillus niger were separated by hplc and subjected to structural determination. amino acid analyses and mass spectra suggested that all of them structurally resembled cyclic pentapeptide malformin a1. two-dimensional nmr experiments and ms/ms experiments led us to deduce cyclo-d-cysteinyl-d-cysteinyl-l-amino acid-d-amino acid-l-amino acid as being the essential structure of malformins.	1993	27314776
structures of antafumicins a and b, novel antifungal substances produced by the fungus aspergillus niger nh-401.	novel antifungal substances, antafumicins a and b, were isolated from a culture of aspergillus niger nh-401 and determined to be trans- and cis-4-(3-acetyl-2,6-dihydroxyphenyl)-2-methoxy-4- butanolide, respectively, by spectroscopic and single crystal x-ray analyses.	1993	27281011
aerobic microorganisms associated with alfalfa leafcutter bees (megachile rotundata).	characterization of microorganisms associated with alfalfa leaf-cutter bee (megachile rotundata) nectar, pollen, provisions, larval guts, and frass (excreta) in alberta demonstrated a varied aerobic microflora. yeasts were isolated frequently from nectar, pollen, and provisions but rarely from guts or frass. the most prevalent yeast taxa were: candida bombicola, cryptococcus albidus, metschnikowia reukaufii, and rhodotorula glutinis. although few filamentous fungi were found in nectar, they were ...	1993	24190009
aspergillus flavus and other mycoflora of groundnut kernels in israel and the absence of aflatoxin.	more than 300 groundnut (peanut) samples collected from different regions of israel were examined by elisa for aflatoxin contamination. samples were designated for export, local consumption or for sowing. none of the samples were contaminated with the toxin. however, when kernels were kept at high humidity (rh≊99%), aflatoxin could be frequently detected seven days after incubation and the toxin was not uniformly distributed among kernels.aspergillus niger, a flavus, penicillium citrinum andp pi ...	1994	23605921
microbial contaminants of commercially bottled non-alcoholic drinks produced in nigeria.	when microbiological analyses were conducted on 90 samples of soft drinks representing 30 different products commercially available in nigeria, contaminants were detected in 50% of them. the isolates were mainly saprophytic and non-pathogenic: bacillus spp. (35%), lactobacillus spp. (26%), pediococcus spp. (6%), staphylococcus epidermidis (6%) and micrococcus spp. (3%) accounted for the bacterial isolates while aspergillus niger (6%) and saccharomyces spp. (16%) accounted for the fungal isolates ...	1994	24421108
influence of water activity on growth and activity of aspergillus niger for glycoamylase production in solid-state fermentation.	growth of aspergillus niger and glucoamylase production correlated well with the water activity of the substrate (wheat bran plus corn flour) in a solid-state fermentation. both were maximal at an initial water activity of 0.936. glycoamylase reached 550 units/g dry substrate after 96 h.	1994	24421106
glucoamylase production by aspergillus niger on rice bran is improved by adding nitrogen sources.	corn steep liquor, peptone or nh inf4 (sup+) salts increased the yield of glucoamylase from aspergillus niger growing in a solid-state fermentation on rice bran up to 360 iu/g dry substrate over 96 h at 30°c.	1994	24421026
coffee husk: an inexpensive substrate for production of citric acid by aspergillus niger in a solid-state fermentation system.	aspergillus niger cftri 30 produced 1.3 g citric acid/10 g dry coffee husk in 72 h solid-state fermentation when the substrate was moistened with 0.075 m naoh solution. production was increased by 17% by adding a mixture of iron, copper and zinc to the medium but enrichment of the moist solid medium with (nh4)2so4, sucrose or any of four enzymes did not improve production. the production of about 1.5 g citric acid/10 g dry coffee husk at a conversion of 82% (based on sugar consumed) under standa ...	1994	24420939
protein enrichment of apple pomace by co-culture of cellulolytic moulds and yeasts.	the co-culture of cellulolytic moulds and yeasts on apple pomace in solid-state fermentation (ssf) and liquid-state fermentation (lsf) increased the protein content of apple pomace. the co-culture of candida utilis and aspergillus niger was the best among several combinations and increased the protein content of dried and pectin-extracted apple pomace to 20% and 17%, respectively, under ssf conditions.	1994	24420900
refined crystal structures of glucoamylase from aspergillus awamori var. x100.	the refined crystal structures of a proteolytic fragment of glucoamylase from aspergillus awamori var. x100 have been determined at ph 6 and 4 to a resolution of 2.2 a and 2.4 a, respectively. the models include the equivalent of residues 1 to 471 of glucoamylase from aspergillus niger and a complete interpretation of the solvent structure. the r-factors of the ph 6 and 4 structures are 0.14 and 0.12, respectively, with root-mean-square deviations of 0.014 a and 0.012 a from expected bondlengths ...	1994	8176747
the pectin lyase-encoding gene (pnl) family from glomerella cingulata: characterization of pnla and its expression in yeast.	oligodeoxyribonucleotide primers were designed from conserved amino acid (aa) sequences between pectin lyase d (pnld) from aspergillus niger and pectate lyases a and e (pela/e) from erwinia chrysanthemi. the polymerase chain reaction (pcr) was used with these primers to amplify genomic dna from the plant pathogenic fungus glomerella cingulata. three different 220-bp fragments with homology to pnl-encoding genes from a. niger, and a 320-bp fragment with homology to pel-encoding genes from nicotia ...	1994	8181749
novel structures of n-linked high-mannose type oligosaccharides containing alpha-d-galactofuranosyl linkages in aspergillus niger alpha-d-glucosidase.	seven oligosaccharides were isolated from alpha-d-glucosidase (ec 3.2.1.20) from aspergillus niger, and the structures of these oligosaccharides were studied by 1h nmr spectroscopy. after treatment of the alpha-d-glucosidase with n-glycosidase f, seven major oligosaccharide peaks were detected by dionex anion-exchange hplc. the structures corresponding to the three peaks os-1, os-2, and os-4 were determined to be man8glcnac2, man9glcnac2, and glcman9glcnac2, respectively, from 1h nmr spectra of ...	1994	8194071
refined structure for the complex of acarbose with glucoamylase from aspergillus awamori var. x100 to 2.4-a resolution.	the three-dimensional structure of the pseudotetrasaccharide acarbose complexed with glucoamylase ii(471) from aspergillus awamori var. x100 has been determined to 2.4-a resolution. the model includes residues corresponding to 1-471 of glucoamylase i from aspergillus niger, a single molecule of bound acarbose, and 535 sites for water molecules. the crystallographic r factor from refinement is 0.124, and the root-mean-squared deviation in bond distances is 0.013 a. electron density for a single m ...	1994	8195212
xylanolytic enzyme production by an aspergillus niger isolate.	production of xylanolytic enzymes by an aspergillus niger ccmi 850 isolate was investigated in batch cultures. the effect of the composition of a fermentation medium that did not include chemical inducers, on beta-xylanase, beta-xylosidase, alpha-l-arabinofuranosidase, and total cellulase activity was studied. with 4% xylan as the carbon source, about 65 u/ml of beta-xylanase was obtained, whereas the total cellulase activity was undetectable, under the specified conditions. this beta-xylanase a ...	1994	8198405
phytase from aspergillus niger.	132 microorganisms, isolates from soil and decayed fruits, were tested for phytase production. all isolates intensively producing active extracellular phytase were of fungal origin. the most active fungal isolates with phytase activity were identified as aspergillus niger. at the end of the growth phase, the extracellular phytase activity produced by a. niger strain 92 was 132 nkat/ml, with strain 89 it was 53 nkat/ml. in both strains the extracellular enzyme activity exhibited two marked activi ...	1994	8549996
aspergilli and lignocellulosics: enzymology and biotechnological applications.	aspergilli are versatile ascomycetes that are able to transform at a rapid rate a wide spectrum of lignin-related aromatic compounds. while it is clear that these fungi can degrade phenolic and polysaccharide components from lignocellulosic material, the status regarding degradation of high-molecular mass lignins is controversial. this review compiles data from the literature as well as that from the authors' laboratory with the aim of clarifying this point. the main body of evidence points towa ...	1994	8167035
investigation on the toxicity of fungi from rootstock snacks.	chicken embryo bioassay was used to monitor the toxicity of extracts from rootstock snack samples during a 210-day storage period. results show that the relative toxicity values which were initially very low increased significantly as from 120th day (when 32% mortality was recorded) up till the last day when 73% was obtained. toxicity of extracts from axenic cultures of 12 fungal species isolated from the snack samples was also determined. the strains of aspergillus chevalieri, rhizopus nigrican ...	1994	8145803
nutritional profile and antimicrobial spectrum of the spice aframomum danielli k. schum.	the spice, aframomum danielli, on a wet weight basis with a moisture content of 10.5%, protein content of 8.2% (dry matter basis) and caloric value of 469.7 kcal/100 g, contains in varying amounts, minerals like calcium, magnesium, sodium, manganese, phosphorus, zinc and copper. amino acids found in varying concentrations in a. danielli include l-threonine, l-serine, l-valine, l-proline, l-glutamic acid, glycine, l-leucine and l-lysine. using minimum inhibition zone of 20-22 mm in diameter, a. d ...	1994	8153068
the use of impedance for preservative efficacy testing of pharmaceuticals and cosmetic products.	impedance was investigated for its applicability to preservative efficacy testing of pharmaceuticals and cosmetics. a good correlation between impedance detection time (td) and total colony counts (colony-forming units (cfu)) was obtained for untreated suspensions of staphylococcus aureus, candida albicans, aspergillus niger and pseudomonas aeruginosa in phosphate-buffered saline (pbs). a good correlation between td and the number of cfu was also obtained for suspensions of test organisms treate ...	1994	8144407
clinical reactions to aspergillus niger in a biotechnology plant: an eight year follow up.	the manufacture of citric acid by fermentation of molasses with aspergillus niger has previously been described as a cause of occupational asthma in a factory. a longitudinal survey of the workforce of this factory has been carried out from 1984 to 1991. over this period 160 of the original 278 workers left the workforce, together with 39 of 76 new recruits. partial enclosure of the process and exhaust ventilation, installed in 1984, was effective in preventing any new cases of occupational asth ...	1994	8124465
apparent digestibility and retention of nutrients bound to phytate complexes as influenced by microbial phytase and feeding regimen in pigs.	five barrows of approximately 45 kg bw, fitted with post-valvular t-cecum cannulas at the ileo-cecal junction, were assigned randomly to five treatments (5 x 5 latin square design) to assess the effect of microbial phytase and feeding regimen (frequency and level) on the apparent digestibilities (total tract [attd] and ileal [aid]) and retention of nutrients. a corn-tapioca-soybean meal diet of low intrinsic phytase activity, containing no added inorganic p, was fed either without or with microb ...	1994	8138479
calcium level affects the efficacy of supplemental microbial phytase in corn-soybean meal diets of weanling pigs.	a 2 x 2 x 2 factorial experiment was conducted with 64 pigs (4 wk old, 8.04 +/- .50 kg bw) to determine the effect of various dietary concentrations of ca, vitamin d, and microbial phytase (aspergillus niger) on phytate-p utilization. a low-p, corn-soybean meal diet was supplemented with two levels of phytase (unit/gram), 750 (suboptimal) and 1,200 (optimal); of vitamin d (international unit/kilogram), 660 (normal) and 6,660 (high); and of ca (percentage), .4 (low) and .8 (normal). pen feed cons ...	1994	8138481
cloning and characterization of the pepd gene of aspergillus niger which codes for a subtilisin-like protease.	serine proteases constitute an important group of extra- and intracellular proteases in fungi. these enzymes are characterized by conserved regions around the active site residues, asp, his and ser. based on this amino acid (aa) sequence conservation, we have used degenerate primer pcr to isolate subtilisin-specific genomic probes from aspergillus niger, and cloned a gene, pepd, by screening a lambda genomic library using a pcr probe. the pepd gene contains three putative introns, which are 51-, ...	1994	8112588
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
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