| soil fungistasis: elevation of the exogenous carbon and nitrogen requirements for spore germination by fungistatic volatiles in soils. | axenic, washed conidia of fusarium solani f. sp. phaseoli, aspergillus flavus, and verticillium albo-atrum were placed on washed difco purified agar discs along with an inorganic salt solution containing various levels of carbon and nitrogen substrates. these discs were exposed to volatiles from six soils (ph 5.1-8.6). fusarium solani macroconidial germination was inhibited mostly by volatiles from soils of ph 5.1, 6.1, 7.0, and 7.5, but high levels of glucose and nh4cl reversed this inhibition, ... | 1975 | 135 |
| a modified minimal medium for aspergillus nidulans. | | 1975 | 328 |
| formation and cleavage of 2-keto-3-deoxygluconate by 2-keto-3-deoxygluconate aldolase of aspergillus niger. | 2-keto-3-deoxygluconate aldolase of aspergillus niger, an enzyme that has not been reported previously, was purified 468-fold. maximal activity was obtained at ph 8.0 and 50 c. the enzyme exhibited relative stereochemical specificity with respect to glyceraldehyde. the km values for 2-keto-3-deoxygluconate, glyceraldehyde, and pyruvate were 10, 13.3, and 3.0 mm, respectively. the effects of some compounds and inhibitors on enzyme activity were examined. stability of the enzyme under different co ... | 1975 | 358 |
| hydrolyzable and nonhydrolyzable 3,4-dichloroaniline-humus complexes and their respective rates of biodegradation. | | 1976 | 1429 |
| basic and neutral amino acid transport in aspergillus nidulans. | arginine and methionine transport by aspergillus nidulans mycelium was investigated. a single uptake system is responsible for the transport of arginine, lysine and ornithine. transport is energy-dependent and specific for these basic amino acids. the km value for arginine is 1 x 10(-5) m, and vmax is 2-8 nmol/mg dry wt/min; km for lysine is 8 x 10(-6) m; kt for lysine as inhibitor of arginine uptake is 12 mum, and ki for ornithine is mm. on minimal medium, methionine is transported with a km of ... | 1976 | 1466 |
| effect of ph on the enzymic activity of the fungi trichothecium roseum and aspergillus niger hydrolyzing nonstarch polysaccharides. | the purpose of the study was to determine optimal ph values for the enzymic activity of the fungi trichothecium roseum and aspergillus niger hydrolyzing nonstarch polysaccharides of barley and disrupting cell walls (cytolysis) of grain, the so called cytolytic enzymes. the effect of the acidity of the medium on the stability of these enzymes was also investigated. in this connection total cytolytic activity (i. e. total activity of the enzymes hydrolyzing nonstarch polysaccharides of cell walls ... | 1975 | 1722 |
| effect of the composition of the nutrient medium on the synthesis of acid-fast alpha-amylase by different strains of aspergillus. | the capacity of 86 strains of the aspergillus fungus to synthesize acid stable alpha-amylase was examined. the strains of asp. niger showing a high capacity of synthesizing the enzyme were isolated. repeated cultivation of the selected cultures on the minoda agar medium led to a 200% increase in the enzyme activity in the submerged culture. addition of sodium nitrate to the minoda medium during submerged cultivation allowed a 3-fold increase of the synthesis of acid stable alpha-amylase. | 1975 | 1736 |
| analysis of acid proteinases from aspergillus terricola. | the specific action and composition of the functional groups of active centres of three fractions of acid proteinases from aspergillus terricola have been studied. with respect to the hydrolysis rates of acetyl-l-phenylalanyl-l-tyrosine and carbobenzoxy-d, l-glycyl-phenylalanine by the three fractions it is suggested that the interaction of acid proteinases with the substrate involves hydrophobic forces. it has been shown that the above fractions are no metal enzymes. by means of the diazocarbon ... | 1975 | 1740 |
| conditions for splitting protodioscine--the main glycoside from tribulus terrestris l. by the enzymatic preparation from aspergillus niger bkmt-33. | the conditions for splitting protodioscine--the main steroid saponine isolated from tribulus terrestris l. by the enzymic preparation of aspergillus niger str. bkmt-33 were investigated. the optimal conditions were found to be as follows: ph 4-5, temperature 30-37 degrees (the substrate concentration--5 mg%, concentration of the enzymic preparation--1%). under these conditions the enzymolysis continued 24 hours. mg+2 and k+ ions accelerated the reaction twice. as a result of the enzymic hydrolys ... | 1975 | 1743 |
| effect of initial ph on aflatoxin production. | the effect of initial ph on aflatoxin production by aspergillus parasiticus nrrl 2999 was examined in a semisynthetic medium. maximal growth, aflatoxin production, and aflatoxin production per unit of growth occurred at initial ph levels of 5.0, 6.0, and 7.0 respectively. initial ph levels less than ph 6.0 favored production of the b toxins, whereas levels greater than ph 6.0 favored production of the g toxins. | 1975 | 2104 |
| high-temperature production of protein-enriched feed from cassava by fungi. | a simple, nonaseptic, low-cast process for the conversion of cassava, a starchy tropical root crop, into microbial protein for use as animal feed was sought. screening tests culminated in the isolation of a thermotolerant, amylase-producing mold, designated i-21, which was identified as aspergillus fumigatus. the optimum ph for protein synthesis was 3-5, but the optimum temperature was less than the desired temperature (larger than or equal to 45 c) required for a nonaseptic fermentation. a. fum ... | 1975 | 2105 |
| caffeine enhancement of digestion of dna by nuclease s1. | the activity of aspergillus orzae nuclease s1 on dna has been investigated under varying ph and metal ion conditions. nuclease s1 was found to preferentially digest denatured dna. with native dna as substrate the enzyme could only digest the dna when caffeine was added to the reaction mixture. the enzyme was more active in sodium acetate buffer (ph 4.5), than in either standard saline citrate (ph 7.0) or sodium phosphate buffer (ph 6.8). caffeine was also found to affect the thermal stability of ... | 1976 | 2867 |
| analysis of acetate non-utilizing (acu) mutants in aspergillus nidulans. | genetic analysis of 119 acetate non-utilizing (acu) mutants in aspergillus nidulans revealed ten new loci affecting acetate metabolism in addition to the three previously recognized on the basis of resistance to fluoroacetate and acetate non-utilization. the enzyme lesions associated with mutations at seven of the acu loci are described. these are: faca (= acua), acetyl-coa synthase; acud, isocitrate lyase; acue, malate synthase; acuf, phosphoenolpyruvate carboxykinase; acug, fructose 1,6-diphos ... | 1976 | 3622 |
| formation of optically-active metabolites of the organophosphorus pesticide phorate by nematodes and microorganisms. | | 1976 | 5242 |
| assimilation of ammonia and growth of biotin deficient aspergillus nidulans. | biotin deficiency in aspergillus nidulans has been found to increase the uptake of ammonium ions, associated with a marked increase in the activity of nadp-linked glutamate dehydrogenase, which is found to be the major route of ammonia assimilation in this culture. the results obtained are discussed with respect to the growth of aspergillus nidulans during biotin deficiency. | 1976 | 5283 |
| enzymatic conversion of sterigmatocystin into aflatoxin b1 by cell-free extracts of aspergillus parasiticus. | a cell-free extract, prepared from aspergillus parasiticus atcc 15517 grown in synthetic medium, was active in converting 14csterigmatocystin into aflatoxin b1 in the presence of reduced nicotinamide adenine dinucleotide phosphate. the activity was demonstrated by the time course of conversion and the linear dependence of the yield of product on enzyme concentrations. optimum activity was obtained at ph 7.5 to 7.8 at 27 c. the results confirm sterigmatocystin as a biogenetic precursor of aflatox ... | 1976 | 5954 |
| adsorption, desorption, and activity of glucose oxidase on selected clay species. | the adsorption of the enzyme glucose oxidase (ec 1.1.3.4) to clays followed the pattern described for other proteins as being ph dependent. maximum adsorption occurred at or below the isoelectric point of the enzyme. the amount of enzyme adsorbed to clay was influenced by the type of clay used, and also the saturating cations. initially adsorbed enzyme showed low specific activities, and as amounts of enzyme adsorbed approached maximum stauration of clay, specific activities increased approachin ... | 1976 | 6139 |
| effect of sugars, hydrogen ion concentration and ammonium nitrate on the formation of citric acid by aspergillus niger. | aspergillus niger mulder strain when grown on a synthetic medium containing urea as the sole source of nitrogen at ph 5.2, formed a mixture of citric and gluconic acids. on growing the organism at ph 2.0 the gluconic acid content was reduced but citric acid yield remained low. addition of nh4no3 to the medium lowered the gluconic acid yields to undetectable levels with a simultaneous increase in the citric acid content. of the sugars used for the production of citric acid, sucrose in an unautocl ... | 1976 | 7101 |
| advantages of x-ray microanalysis in the field of medical mycology. | a new apparatus, which combines an electron microprobe and a scanning electron microscope, has been used. this apparatus enabled to conduct a systematic elemental analysis of two species among aspergillaceae. all elements in the periodic table whose atomic numbers lie between boron and uranium can be detected. | 1975 | 7122 |
| a new method using p-benzoquinone for coupling antigens and antibodies to marker substances. | a method using p-benzoquinone for coupling antigens and antibodies to enzymes and erythrocytes is described. the method involves the treatment of proteins (or polysaccharides) at ph 6 or 7 with an excess of p-benzoquinone. after removal of the unreacted reagent by gel filtration, the "activated" proteins were coupled at ph 8-9 with enzymes or erythrocytes. biological activities of the proteins were not substantially modified by this treatment since 80-100% of the antigen binding capacity was fou ... | 1976 | 7179 |
| purification and characterization of the two molecular forms of aspergillus oryzae acid protease. | the isolation and partial characterization of the acid proteases a1 and a2 (ec3.4.23.6) from aspergillus oryzae grown on solid bran culture are described. the purified preparations were essentially homogeneous by several criteria including sedimentation analysis and polyacrylamide gel electrophoresis. the physiochemical properties of the proteases a1 and a2 were as follows (in the order: a1, a2): molecular weight: 63 000 & 32 000; sedimentation coefficient s20, w: 3.93 and 3.16 s; diffusion cons ... | 1976 | 8138 |
| chlorate toxicity in aspergillus nidulans. studies of mutants altered in nitrate assimilation. | it had previously been held that chlorate is not itself toxic, but is rendered toxic as a result of nitrate reductase-catalysed conversion to chlorite. this however cannot be the explanation of chlorate toxicity in aspergillus nidulans, even though nitrate reductase is known to have chlorate reductase activity. among other evidence against the classical theory for the mechanism of chlorate toxicity, is the finding that not all mutants lacking nitrate reductase are clorate resistant. both chlorat ... | 1976 | 8697 |
| tryptophanyl and carboxylic acid residues in the active centre of glucoamylase i from aspergillus niger. | the ph-dependence of the photo-oxidation of l-tryptophan, in the presence of rose bengal and methylene blue, has been investigated. true, initial rate constants were determined in order to circumvent errors due to secondary processes. photo-oxidation of glycoamylase i from a. niger in the presence of methylene blue or rose bengal resulted in a ph-dependent loss of enzymic activity, which was analogous to the destruction of free l-tryptophan during photo-oxidation. the loss of enzymic activity wa ... | 1976 | 9197 |
| fluorescence behavior of sterigmatocystin. | | 1976 | 9436 |
| studies on the active site of ribonucleases from aspergillus saitoi (author's transl). | | 1976 | 9458 |
| metabolism of dl-(+/-)-phenylalanine by aspergillus niger. | a fungus capable of degrading dl-phenylalanine was isolated from the soil and identified as aspergillus niger. it was found to metabolize dl-phenylalanine by a new pathway involving 4-hydroxymandelic acid. d-amino acid oxidase and l-phenylalanine: 2-oxoglutaric acid aminotransferase initiated the degradation of d- and l-phenylalanine, respectively. both phenylpyruvate oxidase and phenylpyruvate decarboxylase activities could be demonstrated in the cell-free system. phenylacetate hydroxylase, whi ... | 1976 | 10273 |
| cleavage of alpha-l-arabinofuranoside, beta-d-glucopyranoside and beta-cellobioside of 4-nitrophenol by enzymes of various fungi - a contribution to increase the selectivity of tumor therapy. | to carry out long-term experiments as part of a therapy concept of malignant tumours using inactive transport forms of cancerostatic substances and their specific cleavage in the acidic ph region of the tumours by application of extraneous enzymes, we require enzymes with similar catalytic and pharmacokinetic properties which differ from each other in immunological respect. in the search for such enzymes, the alpha-l-arabinofuranosidases from 12 different fungi, among them 9 basidiomycetes, were ... | 1976 | 10689 |
| preparative isolation of terrilytin components and study of their enzymatic properties. | by ion-exchange chromatography the composition of the fibrinolytic enzyme from aspergillus terricola-terrilytine-was studied. the preparation contained five components that differed in their substrate specificity. three of the components and proteolytic and fibrinolytic activities. the isolated fractions were examined with respect to their ph stability, ph optima (casein, hemoglobin and fibrin used as substrates), fibrinolytic and fibrinohenolytic activities. | 1976 | 11462 |
| differential binding of methyl benzimidazol-2-yl carbamate to fungal tubulin as a mechanism of resistance to this antimitotic agent in mutant strains of aspergillus nidulans. | the antimitotic compound methyl benzimidazol-2-yl carbamate (mbc) formed a complex in vitro with a protein present in mycelial extracts of fungi. the binding protein of aspergillus nidulans showed a set of properties which is unique for tubulin. binding occurred rapidly at 4 degrees c and was competitively inhibited by oncodazole and colchicine. other inhibitors of microtubule function such as podophyllotoxin, vinblastine sulfate, melatonin, and griseofulvin did not interfere with binding of mbc ... | 1977 | 12184 |
| cultivation conditions of the aspergillus terricola mutant producing proteolytic enzyme. | the effect of temperature, aeration and various foam suppressors on the growth of a mutant of aspergillus terricola h-20 and on its production of proteolytic enzymes was studied. a high level of the proteolytic activity (12-15 pu/ml) was found at 28-30 degree c in conditions of aeration with the rate of oxygen dissolution being 0.38-0.86 g of oxygen per litre per hour. synthesis of the enzyme was inhibited by a decrease in temperature to 22-24 degree c, a surplass (1.07 g o2 per litre per hour) ... | 1976 | 12453 |
| lytic enzymes in the autolysis of filamentous fungi. | the degrees of autolysis attained by five different genera of filamentous fungi during an incubation period of 60 days, under the same culture conditions were: 87.3% for penicillium oxalicum; 65.9% for neurospora crassa; 62.7% for polystictus versicolor; 51.7% for aspergillus niger and 23.5% for nectria galligena. n. crassa, a. niger and p. versicolor reached the end of the autolysis during this incubation period (60 days), whereas p. oxalicum and n. galligena did not. the excretion of the lytic ... | 1976 | 13304 |
| evidence for the presence of membrane-bound forms of acid protease in aspergillus oryzae. | | 1977 | 13792 |
| characterization of beta-galactosidase from a special strain of aspergillus oryzae. | beta-galactosidase ec 3.2.1.23 was isolated from a partially purified preparation obtained from cultured cells of a special strain of aspergillus oryzae, rt 102 (ferm-p1680). the enzyme preparation gave a single protein band on polyacrylamide gel electrophoresis and was free from alpha-galactosidase, alpha- and beta-mannosidase, alpha- and beta-n-acetylhexosaminidase, and protease activities. the beta-galactosidase was capable of acting on aryl beta-galactosides, lactose, and lactosides. it also ... | 1976 | 14118 |
| mechanism of amylase action on glucoside starch bonds. | functional groups of glucoamylase and alpha-amylase from asp. awamori, alpha-amylase from asp. oryzae and alpha- and beta-amylases from barley malt are identified. kinetic curves of the activity dependency on ph, values of ionization heats and photooxidative inactivation draw to the conclusion that carboxyl-imidazole system enters into the active site of the enzymes. a hypothetic mechanism of hydrolysis of alpha-1,4-glucoside bond in starch molecule by alpha- and beta-amylases and of alpha-1,4- ... | 1976 | 14726 |
| aminoacylase pellets. | aminoacylase was immobilized on the mycelium pellets of aspergillus ochraceus by using albumin and glutaraldehyde. no difference in the optimum ph was observed between native aminoacylase and aminoacylase pellets. the aminoacylase pellets were stable in ph 4-8 but they were unstable in alkaline conditions. the aminoacylase pellets were more stable against heavy metal ions and inhibitors than native aminoacylase. however, the degree of the activation of aminoacylase with cobalt ion decreased with ... | 1977 | 14748 |
| use of amylum derivatives for isolation of amylolytic enzymes. | in a leading article literature is reviewed concerning isolation of amylolytic enzymes by adsorption on differently modified starches, resp. on other adsorbents. deae amylum, deahp amylum and deae-sephadex a 25 were found to be most suitable adsorbents. the other adsorbents examined did not reach claimed parameters. | 1977 | 15219 |
| isolation of amylolytic system of aspergillus oryzae by sorption on deahp amylum. | conditions of effective sorption of amylolytic enzyme from a solution or from fermentative liquid on deahp amylum were studied. isolating action is in a direct dependence on the relation between activity and amount of deahp amylum, the curve of this dependence was illustrated. the enzyme can be released by elution or adsorbate can be used in a pulverised from. in the conclusion of the work laboratory isolation technique is described. | 1977 | 15220 |
| mycotoxicoses. | | 1976 | 15366 |
| 6-mfa, an antiviral agent from aspergillus ochraceus atcc 28706: influence of body weight and mineral oil administration of the antiviral activity in mice. | sera obtained from mice treated with 6-mfa, an antiviral agent from aspergillus ochraceus atcc 28706 showing high interferon activity, could be transferred to healthy animals to make them resistant to semliki forest virus (sfv) infection. body weight of mice directly influenced, within limits, the proportion of treated mice surviving challenge virus infection as well as interferon production. mineral oil (liquid paraffin, b. p.) administered prior to 6-mfa increased both the level of interferon ... | 1977 | 15439 |
| isolation, purification and investigation of physico-chemical properties and specificity of leu-gly-gly-amino peptidase. | a highly purified (237-fold) preparation of extracellular leu-gly-gly aminopeptidase was isolated from the 716 strain of mould aspergillis flavus. the enzyme was found electrophoretically and enzymatically homogeneous, using leu-beta-naphthylimide as substrate. the ph optimum is 8.60; the temperature optimum is about 50 degrees c. the enzyme was inhibited by edta and completely reactivated by co2+ ions; ca2+ and mn2+ ions considerably restored the enzyme activity. the enzyme showed the optimal a ... | 1976 | 15640 |
| extracellular acid protease of aspergillus oryzae grown on liquid media: multiple forms due to association with heterogeneous polysaccharides. | the acid protease (ec 2.4.23.6) that is produced extracellularly when aspergillus oryzae is grown on liquid media has been isolated and characterized. the enzyme was purified by precipitation with tannic acid, chromatography on duolite a-2, and gel filtration on sephadex g-100. the last step yielded four active components, with varying molecular weights ranging from 42,000 to 60,000. two of them, designated e1 and e1a, with molecular weights of 60,000 and 55,000, respectively, were heterogeneous ... | 1977 | 15987 |
| studies on the toxin of aspergillus fumigatus. vii. purification and some properities of hemolytic toxin (asp-hemolysin) from culture filtrates and mycelia. | a hemolytic toxin has been obtained from mycelia and culture filtrates of aspergillus fumigatus by the procedures that included precipitation with ammonium sulfate, chromatography of deae-sephadex, affinity chromatography on concanavalin a-sepharose and gell filtration on sephadex g-50, g-100 and g-150. the purified homolytic toxin was homogeneous on immunological and disk electrophoretic analysis, and the toxin from culture filtrates was identical with that from mycelia by the immunodiffusion t ... | 1977 | 16196 |
| gluconic acid forming enzymes in aspergillus niger (author's transl). | at least three gluconic acid forming enzymes were identified in cell-free extracts of aspergillus niger: glucose oxidase (ec 1.1.3.4), a glucose dehydrogenase (ec 1.1.99.10), and an enzyme or a mixture of enzymes catalyzing the cleavage of 6-phosphogluconate into gluconate and inorganic phosphate. 2,6-dichlorphenolindophenol was one of the hydrogen acceptors in vitro of the glucose dehydrogenase. some properties of this enzyme (km values, ph-dependence, substrate and hydrogen acceptor specificit ... | 1977 | 16416 |
| in vivo and in vitro studies of nitrate reductase regulation in asperillus nidulans. | induced wildtype cells of a. nidulans rapidly lost nadph--linked nitrate reductase activity when subjected to carbon and or nitrogen starvation. a constitutive mutant at the regulatory gene for nitrate reductase, nir ac 1, rapidly lost nitrate reductase activity upon carbon starvation. this loss of activity is thought to be due to a decrease in the nadph concentration in the cells. cell free extracts from wildtype cells grown in the presence of nitrate, rapidly lost their nitrate reductase activ ... | 1977 | 17826 |
| effect of cadmium on fungi and on interactions between fungi and bacteria in soil: influence of clay minerals and ph. | fungi (rhizopus stolonifer, trichoderma viride, fusarium oxysporum f. sp. conglutinans, cunninghamella echinulata, and several species of aspergillus and penicillium) tolerated higher concentrations of cadmium (cd) when grown in soil than when grown on laboratory media, indicating that soil mitigated the toxic effects of cd. in soil amended with clay minerals, montmorillonite provided partial or total protection against fungistatic effects of cd, whereas additions of kaolinite provided little or ... | 1977 | 18085 |
| phosphate uptake and involvement of binding protein in tween-80 supplemented culture of aspergillus fumigatus. | tween-80 supplementation in submerged culture of aspergillus fumigatus resulted in an increase of phosphate uptake. the uptake system was characterized as saturable, energy-dependent and operating against the concentration gradient. control and tween 80 cultures showed similar km values for phosphate uptake (50 micrometer). cold osmotic shock treatment of the cultures was found to cause considerable reduction in the ability to take up phosphorus with concomitant release of the binding protein in ... | 1977 | 18385 |
| circular dichroism studies on the n-bromosuccinimide oxidation of ribonuclease from aspergillus saitoi. | | 1977 | 18443 |
| enzyme composition of the lysosomes of aspergillus clavatus. | | 1977 | 18654 |
| properties of chymotrypsin proteinase from aspergillus oryzae. | chymotrypsin-type proteinase is detected in the proteolytic system of asp. oryzae. the action of it and chymotrypsin is shown to depend on formaldehyde. hydrolysis of substrates, p-nitrophenyl acetate (p-npa) and n-benzoyl-tyrosine methyl ether (btme), by both preparations is almost the same. the obtained activity ph-optimum for the studied proteinase esterolytic activity is located in the alkaline zone as well as for crystalline chymotrypsin (substrate p-npa). it concerns ph of both enzymes sta ... | 1977 | 18830 |
| rapid induction of alpha-amylase by nongrowing mycelia of aspergillus oryzae. | a rapid induction system for synthesis of alpha-amylase by the funga aspergillus oryzae m-13 was established. the mycelia were prepared from 20-h cultures grown on a peptone-glycerol medium and starved for 5 h; maltose was the optimum inducer tested. during h 1 of induction, formation of both intra- and extracellular alpha-amylases occurred at an almost identical rate (70 to 80 microgram/g of cells-h) without a detectable lag period. after a 1-h induction period, a remarkable increase in the ext ... | 1977 | 18989 |
| purification and properties of a cellulase from aspergillus niger. | a cellulolytic enzyme was isolated from a commercial cellulase preparation form aspergillus niger. a yield of about 50mg of enzyme was obtained per 100g of commerial cellulase. the isolated enzyme was homogeneous in the ultracentrifuge at ph 4.0 and 8.0, and in sodium dodecyl sulphate/polyacrylamide-gel electrophoresis but showed one major and two minor bands in disc gel electrophoresis. no carbohydrate was associated with the protein. amino acid analysis revealed that the enzyme was rich in aci ... | 1977 | 19015 |
| preparation and properties of a new dnase from aspergillus oryzae. | a dnase present in commercial preparations of aspergillus oryzae alpha-amylase was purified 1550-fold in 25% yield by acetone precipitation and by chromatography on diethylaminoethyl- and carboxymethylcellulose. the enzyme was isolated free of contaminating rnases and dnases. the molecular weight of the enzyme determined by gel filtration on sephadex g-100 was 48 000, while a molecular weight of 58 000 was determined for the single band observed upon polyacrylamide gel electrophoresis in sodium ... | 1977 | 19042 |
| isolation and properties of leucine aminopeptidase from aspergillus oryzae. | homogenious leucine aminopeptidase is purified from "oryzine"--mixture of enzymes produced by surface culture of asperigillus oryzae using treatment with activated characoal, followed by deae-cellulose and hydroxylapatite chromatographies, biogel p-100 gel-filtration and polyacrylamide-gel electrophoresis. the enzyme has ph optimum 9.0 and the molecular weight 37500 as estimated by gil-filtration through sephadex g-100 (superfine) and sds-polyacrylamide gel electrophoresis. leucine aminopeptidas ... | 1977 | 19097 |
| induction of the acetamidase of aspergillus nidulans by acetate metabolism. | growth tests and enzyme determinations strongly suggest that the acetamidase of aspergillus nidulans is induced by a product of acetate metabolism rather than the substrate, acetamide. the cis-dominant mutation, amdi9, which is closely linked to amds, the structural gene for the acetamidase, results in greatly increased sensitivity to induction by acetate metabolism. propionate, l-threonine, and ethanol also result in acetamidase induction. mutations in the faca, facb, and facc genes, which lead ... | 1977 | 19418 |
| interaction of asp. melleus semi-alkaline protease with benzeneboronic acid. | benzeneboronic acid (bba), a possible transition-state analog for serine proteases, was found to inhibit asp. melleus semi-alkaline protease ec 3.4.21.15. the ph dependence of inhibitor constants was studied by the ph-stat method using n-acetyl-l-tyrosine ethyl ester as a substrate at 25 degrees c. from the ph dependence of the association constant (reciprocal inhibitor constant), a pk value of 6.6, which may be attributable to the catalytic histidine residue of the enzyme, was estimated. the bb ... | 1977 | 19429 |
| c-terminal peptidyl-l-proline hydrolase activity of aspergillus acid carboxypeptidase. | aspergillus saitoi acid carboxypeptidase hydrolyzed c-terminal peptidyl-l-proline bonds and released the c-terminal proline from z-gly-pro-leu-gly-pro and z-gly-pro at ph 3.3. proline liberated by the enzymic reaction was measured by a sensitive colorimetric ninhydrin method in glacial acetic acid at 513 nm. a km value of 1.0 mm and a kcat value of 0.09 s-1 for z-gly-pro-leu-gly-pro hydrolysis, and a km value of 5.0 mm and a kcat value of 0.0045 s-1 for z-gly-pro hydrolysis were calculated from ... | 1977 | 19444 |
| effects of various acids and salts on growth and aflatoxin production by aspergillus flavus nrrl 3145. | the effects of sodium chloride, sodium acetate, benzoic acid, sodium benzoate, malonic acid, and sodium malonate on growth and aflatoxin production by aspergillus flavus were investigated in synthetic media. sodium chloride at concentrations equivalent to or greater than 12 g/100 ml inhibited growth and aflatoxin production, while at 8 g or less/100 ml, growth and aflatoxin production were stimulated. at 2 g or less/100 ml, sodium acetate also stimulated growth and aflatoxin production, but redu ... | 1976 | 19682 |
| purification of an acid proteinase from aspergillus saitoi and determination of peptide bond specificity. | the specificity and mode of action of an acid proteinase (ec 3.4.23.6) from aspergillus saitoi were investigated with oxidized b-chain of insulin, angiotensin ii and bradykinin. further purification of acid proteinase was performed with n,o-dibenzyloxycarbonyl-tyrosine hexamethylene-diamino-sepharose 4b affinity chromatography and isoelectric focusing. the purified enzyme was free of any other proteolytic activity demonstrated in asp. saitoi. acid proteinase from asp. saitoi hydrolyzed primarily ... | 1977 | 21699 |
| metabolism of mandelic acid by neurospora crassa. | preliminary studies on the metabolism of manelic acid by neurospora crassa reveal the operation of a pathway for its degradation which involves benzoyl formic acid, benzaldehyde, benzoic acid, 4-hydroxybenzoic acid, and protocatechuic acid as the intermediates. this pathway is different from the followed by bacterial systems and is the same as that observed in aspergillus niger. | 1977 | 21739 |
| penicillic acid production in submerged culture. | twenty known penicillic acid (pa)-producing aspergillus and penicillium cultures were grown under various conditions in shaken flasks to determine the highest yielding strains and their requirements for maximum toxin production. abilities of the cultures to utilize eight different carbon sources in raulin-thom medium for mycotoxin synthesis were determined at four different incubation temperatures: 15, 20, 25, and 28 degrees c. of the 20 cultures, p. cyclopium nrrl 1888 was superior, yielding up ... | 1977 | 22310 |
| mutagenic and recombinogenic action of pesticides in aspergillus nidulans. | thirteen pesticides, aminotriazole, benomyl, captafol, captan, dalapon-na, dichlorvos, dinobuton, dodine, ioxynil, mecoprop, neburon, picloram and tordon were tested for ability to induce (1) point mutations to 8-azaguanine resistance, (2) mitotic crossing-over, and (3) mitotic non-disjunction and haploidization in aspergillus nidulans. tests were performed at three different phs, i.e. 4.5, 7, 8.2. three of the pesticides, captan , captafol and dichlorvos induced point mutations; dichlorvos also ... | 1977 | 22812 |
| photooxidation and carbethoxylation of a minor ribonuclease from aspergillus saitoi. | in order to investigate the nature of amino acid residues involved in the active in the active site of a ribonuclease from aspergillus saitoi, the ph dependence of the rates of inactivation of rnase ms by photooxidation and modification with diethylpyrocarbonate were studied. (1) rnase ms was inactivated by illumination in the presence of methylene blue at various ph's. the ph dependence of the rate of photooxidative inactivation of rnase ms indicated that at least one functional group having pk ... | 1977 | 23378 |
| increased and decreased sensitivity to carbon catabolite repression of enzymes of acetate metabolism in mutants of aspergillus nidulans. | the crea204, creb15 and crec27 mutations have been shown to cause carbon catabolite derepression of acetly coa synthase and isocitrate lyase in aspergillus nidulans. a recessive mutation, cre-34, which is linked to the crec gene, results in these enzymes being more sensitive than cre or wildtype strains to catabolite repression. the acetamidase levels of strains containing cre mutations have been investigated and provide support for the hypothesis that an acetate metabolite, rather than acetamid ... | 1977 | 23491 |
| optimal conditions of alpha-amylase production by aspergillus oryzae in liquid media. | the alpha-amylase secretion in a mineral culture medium containing starch and glucose follow the lysis of mycelium. this lysis seems to result from the hydrolysing action of dextranase and levulanase on cell wall. cell lysis and amylase secretion are greatly enhanced by ph elevation of culture medium (optimal ph 8,8). in such conditions of production the amylase is not stable but can be stabilized by addition of starch. a method is described using ph and starch content modifications, which allow ... | 1977 | 23718 |
| chemical modification of cellulase from aspergillus niger. | n-bromosuccinimide completely inactivated the cellulase, and titration experiments showed that oxidation of one tryptophan residue per cellulase molecule coincided with 100% inactivation. cm-cellulose protected the enzyme from inactivation by n-bromosuccinimide. the cellulase was inhibited by active benzyl halides, and reaction with 2-hydroxy-5-nitrobenzyl bromide resulted in the incorporation of 2.3 hydroxy-5-nitrobenzyl groups per enzyme molecule; one tryptophan residue was shown to be essenti ... | 1977 | 23759 |
| fractionation and purification of endo-1,4-beta-xylanases and exo-1,4-beta-xylosidases of aspergillus niger. | two endo-1,4-beta-zylanases (m. w. 24,000 and 41,000) and six exo-1,4-beta-xylosidases, differing in their molecular weights and isoelectric points, were found in a xylanase preparation from aspergillus niger, using different methods of fractionation. an electrophoretically homogeneous exo-1,4-beta-xylosidase (m. w. 30,000) purified 120-fold, with pi 4.6, having optimal effect on methyl-beta-d-xyloside at ph 3.0 was obtained. exo-1,4-beta-xylosidase splits off xylose from the ends of the xylan c ... | 1977 | 15659 |
| glycoprotein enzymes secreted by aspergillus niger: purification and properties of alpha-glaactosidase. | an alpha-galactosidase (alpha-d-galactoside galactohydrolase ec 3.2.1.22) was purified to homogeneity from the culture filtrate of aspergillus niger. the enzyme had an apparent molecular weight of 45,000 and was a glycoprotein. radioactive enzyme was prepared by growing cells in 14cfructose and this enzyme was used to prepare 14c-labeled glycopeptides. the glycopeptides emerged from sephadex g-50 between stachyose and the glycopeptide from ovalbumin. based on calibration of the column with vario ... | 1977 | 14112 |
| pharmaceutical studies on aminopeptidase from aspergillus japonica. | | 1976 | 13938 |
| immobilization of alpha-amylase on porous glass and silochrome. | immobilized forms of alpha-amylase from aspergillus oryzae were prepared on the porous glass and silochrome by the glutaraldehyde method. an addition of calcium ions at a concentration of 0.05 m to the reaction mixture during immobilization stabilized the enzyme activity. ph optimum of the insoluble form of alpha-amylase was 5.8 and that of the soluble form was 4.7. storage of the insoluble enzyme as water suspension in 0.015 m cacl2 at 4 degrees c for six months and twenty times repeated specif ... | 1978 | 24839 |
| purification and characterization of the two molecular forms of membrane acid protease from aspergillus oryzae. | two forms (m1 and m2) of the membrane-bound acid protease of aspergillus oryzae have been purified by extraction with triton x-100, washing with cold acetone, and repeated gel filtration on bio-gel a-15 m in the presence and absence of triton x-100. the purified membrane enzymes, m1 and m2, moved as a single band in acrylamide gel electrophoresis and had apparent molecular weights of 150 000 and 60 000, respectively, as estimated by sodium dodecyl sulfate/acrylamide gel electrophoresis. these tw ... | 1978 | 25177 |
| ph-profiles of the kinetic parameters of a minor ribonuclease from aspergillus saitoi. | | 1978 | 25272 |
| immobilization of aspergillus beta-glucosidase on chitosan. | beta-glucosidase of aspergillus phoenicis qm 329 was immobilized on chitosan, using the bifunctional agent glutaraldehyde. the most active preparation based on the amount of support contained a 1:2.5 enzyme-to-chitosan ratio (wt/wt). however, the specific activity of the bound enzyme decreased from 10 to 1% with increasing enzyme-to-chitosan ratio. compared with free beta-glucosidase, the immobilized enzyme exhibited: (i) a similar ph optimum but more activity at lower ph values; (ii) improved t ... | 1978 | 25624 |
| how much is secondary structure responsible for resistance of double-stranded rna to pancreatic ribonuclease a? | 1. double-stranded f2 sus11 or qbeta rnas, resistant to bovine pancreatic rnaase a in 0.15 m nacl/0.015 m sodium citrate (ssc), are quickly and completely degraded at 10-fold lower ionic strength (0.1 x ssc) under otherwise similar conditions. at this ionic strength the secondary structure of double-stranded rna is maintained, as judged by the following: (a) the unchanged resistance of double-stranded rna and dna, under similar low ionic strength conditions, to nuclease s1 from aspergillus oryza ... | 1978 | 26405 |
| purification and properties of one component of acid phosphatase produced by aspergillus niger. | one component, the i form, of acid phosphatase (orthophosphoric-monoester phosphohydrolase (acid optimum), ec 3.1.3.2) produced by aspergillus niger was purified from the mycelial extract. the purified enzyme was homogenous on sephadex g-200 gel filtration, disc electrophoresis and heat inactivation. the purified enzyme was studied and the following results were obtained: 1. the enzyme catalyzed the hydrolysis of a wide variety of phosphomonoesters, but not that of bis(p-nitrophenyl)phosphate, a ... | 1977 | 13843 |
| energy-driven uptake of humic acids by aspergillus niger. | the uptake of humic acids by mycelia of aspergillus niger was demonstrated to be energy-dependent with a sensitivity to sodium azide and to 2,4-dinitrophenol. greater uptake of humic acids by submerged mycelium occurred at ph 3.0 and at 32 degrees c. the rate of uptake was influenced by the concentration of humic acids with an apparent km of 0.2 grams/ml and with a vmax of 0.13 mg humic acids per gram mycelial dry weight.10 min-1. in the absence of added energy source, vmax of 0.05 mg humic acid ... | 1978 | 26456 |
| sustrate-specificity of glucomylase (e.c. 3.2.1.3) exemplified by p-nitroaniline n-glucosides. | the present paper supplements the previous investigations on the mechanism of reactions catalyzed by amylolytic enzymes. the performed experiments corroborated the data on transglucosylative properties of animal glucoamylases which were found to depend on the structure and concentration of substrate. the p-nitroanilines were first introduced in this type of research enabling to find the differences of activity mechanism of animal glucoamylases and aspergillus niger glucoamylase. in complement to ... | 1976 | 13765 |
| effect of the composition of the medium and the conditions of aspergillus foetidus cultivation on the biosynthesis of glucoamylase. | the optimal conditions for biosynthesis of exocellular glucoamylase were found in the course of submerged cultivation of aspergillus foetidus atcc 14916: ph 4.5 at the beginning of cultivation, cultivation for four days, a temperature of 30 degrees c, and an aeration in the fermenter of 1.5 volumes of the air per 1 volume of the medium with a stirring of 280 rpm. the material can be inoculated either as spores (1 x 10(7) spores per 100 ml of the medium) or a material germinated from spores (5% b ... | 1978 | 26852 |
| purification and properties of d-amino acid oxidas of aspergillus niger. | | 1976 | 13036 |
| the structure and function of acid proteases. vi. effects of acid protease-specific inhibitors on the acid proteases from aspergillus niger var. macrosporus. | 1. the type b acid protease from aspergillus niger var. macrosporus was inactivated by reaction with diazoacetyl-dl-norleucine methyl ester (dan), dl-1-diazo-3-tosylamido-2-heptanone (dth), and l-1-diazo-3-tosylamido-4-phenyl-2-butanone (dtpb) in the presence of cupric ions. the reaction with dan took place with 1:1 stoichiometry. the enzyme was also inactivated by reaction with 1, 2-epoxy-3-(p-nitrophenoxy)-propane (epnp) with concomitant incorporation of approximately two epnp molecules per mo ... | 1976 | 12156 |
| use of aspergillus flavus to evaluate the relative nutritive value in cultivars of rye, wheat and triticale. | | 1976 | 11366 |
| synthesis of chitin by particulate preparations from aspergillus flavus. | cell-free extracts from aspergillus flavus catalyzed the synthesis of chitin from udp-glcnac. most of the activity was associated with membrane-rich fractions whereas no activity was detected in the cell walls. chitin synthetase was activated by fungal acid proteases; animal and plant proteases destroyed it. upon incubation at 0 c and 28 c chitin synthetase was inactivated, probably by the action of proteases present in the particulate preparations. maximal activity was obtained at ph 6.6-7.1 an ... | 1976 | 10833 |
| microbial biodegradation of cellophase. | the microbial biodegradation of cellophane (u.c.b.--division sidac) was studied. preliminary experiments with pure cultures of seven cellulolytic microorganisms (aspergillus sp., penicillium sp., chaetomium crispatum, ch. globosum, sclerotium rolfsii and two actinomycetes) revealed that the substrate as such was very recalcitrant, probably due to the occurrence of insoluble coating agents. therefore, mixed cultures of the above mentioned cellulolytic microorganisms were used as inoculum. the cel ... | 1978 | 29381 |
| presence and partial characterization of internal acid protease of aspergillus oryzae. | the presence and partial characterization of the internal acid protease (ec 2.4.23.6) of aspergillus oryzae has been investigated. although the majority of the acid protease is external and present in the culture filtrate, a significant amount of the active enzyme is firmly bound to the cells; it is not released by repeated extraction of cells with 0.9% sodium chloride but is liberated into the soluble fraction during disruption of cells. the internal acid protease, as well as the external one, ... | 1978 | 29561 |
| prevalence of fungi during skylab missions. | samples for mycological analysis were collected from surfaces in the skylab spacecraft before launch and during flight for each manned mission. fungal contamination levels were low during the first two flights; however, the species recovered were different for each mission. on the third mission, widespread contamination of the skylab spacecraft with aspergillus and pencillium spp. was detected. this contamination was traced to several contaminated space suit undergarments. | 1978 | 29562 |
| the structure and function of acid proteases. v. comparative studies on the specific inhibition of acid proteases by diazoacetyl-dl-norleucine methyl ester, 1,2-epoxy-3-(p-nitrophenoxy) propane and pepstatin. | comparative studies have been made on the effects of diazoacetyl-dl-norleucine methyl ester (dan), 1,2-epoxy-3-(p-nitrophenoxy)propane (epnp) and pepstatin on acid proteases, including those from acrocylindrium sp., aspergillus niger, aspergillus saitoi, mucor pusillus, paecilomyces varioti, rhizopus chinensis, and trametes sanguinea, and also porcine pepsin ec 3.4.23.1 and calf rennin ec 3.4.23.4 for comparative purposes. these enzymes were rapidly inactivated at similar rates and in 1:1 stioch ... | 1976 | 10290 |
| [acid-stable and acid-unstable alpha-amylases of the mold fungi aspergillus]. | acid-sable alpha-amylase of asp. niger and acid-unstable, alpha-amylase of asp. oryzae were studied. it was demonstrated, that beside being a more acid-stable properties, alpha-amylase asp. niger has increased thermal stability as compared to alpha-amylase asp. oryzae. the molecular weights of acid-stable alpha-amylase and acid-unstable alpha-amylase are 58 000 and 51 000, respectively. the amino acid composition, and the c- and n-terminal amino acids of both forms of alpha-amylases were determi ... | 1978 | 31203 |
| [properties of immobilized acid proteinase from aspergillus awamori]. | ph-optimum, thermal stability and storage stability of immobilized acid proteinase from aspergillus awamori obtained by covalent binding on silochrome through glutaraldehyde were studied. acid proteinase immobilization was found to shift towards the acid range by a unit. thermal stability of the immobilized preparation was lower than that of the native enzyme. | 1978 | 31618 |
| current status of treatment in storage disorders. | | 1976 | 10023 |
| antifungal properties of alpha,omega-alkanedicarboxylic acids and their dimethyl esters. | thirteen alpha, omega-alkanedicarboxylic acids (c2-c12, c14, and c16) and their dimethyl esters were tested against aspergillus niger, trichoderma viride, and myrothecium verrucaria in sabourauc dextrose agar at ph 4.0 and 5.6. toxicity to canadida albicans, trichophyton mentagrophytes, and mucor mucedo was determined in the same medium at ph 5.6 and 7.0 in the absence and presence of 10% beef serum. the dicarboxylic acids possessed very poor to no antifungal activity against all six fungi. the ... | 1976 | 9194 |
| further characterization of the reduced nicotinamide adenine dinucleotide phosphate: nitrate oxidoreductase in aspergillus nidulans. | the reduced nicotinamide adenine dinucleotide phosphate (nadph):nitrate oxidoreductase (ec 1.6.6.2) from aspergillus nidulans wild-type bi-1 was purified by means of salt fractionation, gel filtration, affinity chromatography, and polyacrylamide gel electrophoresis. enzyme which was adsorbed on cibacron blue agarose could be eluted with 2 mm nadph or 2 mm oxidized nadp (nadp(+)), the former being about three times more effective than the latter. about half the total nadph:nitrate reductase activ ... | 1979 | 33144 |
| a particulate chitin synthase from aspergillus flavus link: the properties, location, and levels of activity in mycelium and regenerating protoplast preparations. | chitin synthase (ed 2.4.1.16) has been characterized in aspergillus flavus. a k(m) value of 2.5 m(m) was obtained for the substrate udpglcnac. the enzyme had a requirement for glcnac, and mg2+ and activity was increased in the presence of soluble chitodextrins f1 and f2. the optimum activity was obtained using tris--hcl buffer, ph 7.5, with a secondary peak at ph 6.2 and an incubation temperature of 29.5 degrees c. distribution patterns of chitin synthase in protoplasts and mycelial material wer ... | 1976 | 9191 |
| citrate regulation of nadp+-specific isocitrate dehydrogenase of aspergillus niger [proceedings]. | | 1978 | 33856 |
| comparative studies of three exo-beta-glycosidases of aspergillus oryzae. | beta-glucosidase [beta-d-glucoside glucohydrolase ec 3.2.1.21] and beta-galactosidase [beta-d-galactoside galactohydrolase, ec 3.2.1.23] of takadiastase were purified by acetone fractionation, deae-cellulose, and hydroxylapatite chromatography. purity was confirmed by disc electrophoresis, ultracentrifugation and measurement of other glycosidase activities which coexisted in takadiastase. molecular weight of the beta-glucosidase was 218,000 by sedimentation equilibrium and 110,000-116,000 by sds ... | 1979 | 33973 |
| pepstatin-insenstive acid proteases from scytalidium lignicolum. kinetic study with synthetic peptides. | a kinetic study was conducted on the acid proteases a-1 and a-2 from scytalidium lignicolum using synthetic peptides as substrates. almost maximum activity was attained with n-acylated tetrapeptides as the molecular size of substrates was increased. suitable amino acid residues were required at the p1-p2 and p1'-p2' positions [notation of schechter and berger (14)]. hydrophobic or bulky residues such as leucine were specifically required at the p1 and p1' positions, with the specificity at the l ... | 1979 | 34596 |
| the role of precipitins and complement activation in the etiology of allergic lung disease. | an experimental model of allergic lung disease has been described that is monitored by analysis of arterial oxygen tension following aerosol challenge with antigen. rabbits immunized to a classical soluble antigen, human serum albumin (hsa), to the point where severe arthus skin reactivity was demonstrable, were aerosol-challenged with antigen. arterial oxygen tension measurements made on pre- and post-challenge samples yielded early, late, and continuous response patterns, reminiscent of those ... | 1976 | 7583 |
| single-stranded regions in streptococcus pneumoniae chromosomal deoxyribonucleic acid and their relation to transformation. | deoxyribonucleic acid (dna) in lysates of both completent and noncompetent streptococcus pneumoniae cells was characterized by chromatography on benzoylated, naphthoylated diethylaminoethyl-cellulose columns, by sensitivity to aspergillus oryzae s1 endonuclease, and by sucrose gradient analysis. the dnas from both competent and noncompetent cells were found to contain similar extents of single-stranded regions. these single-stranded regions appeared to be intact, unpaired regions in double-stran ... | 1979 | 35514 |
| [stability of alpha-amylase with immobilization through its different functional groups]. | the paper deals with stability of aspergillus aryzae alpha-amylase immobilized on cm- and ae-celluloses using n,n'-dicyclohexylcarbodiimide by means of binding through its amine or carboxylic groups. the binding of the enzyme with cm-cellulose makes its preparations more stable to the effect of edta and elevated temperature (50 degrees c) than under fixation on ae-cellulose. | 1979 | 36704 |
| clostridium botulinum growth and toxin production in tomato juice containing aspergillus gracilis. | the ability of spores of one type a and one type b strain of clostridium botulinum to grow and produce toxin in tomato juice was investigated. the type a strain grew at ph 4.9, but not at ph 4.8; the type b strain grew at ph 5.1, but not at ph 5.0. aspergillus gracilis was inoculated along with c. botulinum spores into ph 4.2 tomato juice; in a nonhermetic unit, a ph gradient developed under the mycelial mat, resulting in c. botulinum growth and toxin production. in a hermetic unit, mold growth ... | 1979 | 36843 |
| interaction of radical anion probes with glucoamylase i from aspergillus niger. | the radical anions (scn)2.- and br2.- produced during a pulse radiolysis of the respective potassium salts have been used to study the tryptophan residues of the glucoenzyme, glucoamylase i (ec 3.2.1.3.). at neutral ph, br2.- reacted with the tryptophan residues of glucoamylase i as expected from previous studies of proteins and free amino acids. however, (scn)2.- at neutral and high ph was surprisingly unreactive towards the native enzyme. reaction did occur, however, between (scn)2.- and gluco ... | 1978 | 38219 |
| [immobilization of aspergillus oryzae aminopeptidase on organic and inorganic carriers]. | the process of asp. oryzae aminopeptidase immobilization on organic (ae-cellulose, sepharose 4b, sephadex g-200) and inorganic (sch-2, sch-3 sylochromes and kck n 1 silicagel) carriers was studied. aminopeptidase immobilized on sephadex g-200 contains the largest amount of protein (80 mg per 1 g of carrier) and is the most active of all other preparations. the immobilized preparations retain the temperature optimum, like the soluble form, at 60 degrees c, except the preparation immobilized on ae ... | 1979 | 38548 |