Showing papers on "Aspergillus niger published in 1979"
TL;DR: In this paper, the amount of synthesized ester was estimated by alkalimetry, and products were identified by thin-layer chromatography and infrared spectroscopy, using homogeneous enzyme preparations.
151 citations
TL;DR: Five different xylanases and a β-D-xylosidase in the culture medium of Aspergillus niger have been purified to homogeneity from 13- to 52-fold by a procedure of gel and hydroxylapatite chromatography, and all seemed to be capable of liberating L-arabinose from either arabinoxylan or the arabinose–xylose oligosacc...
Abstract: Five different xylanases and a β-D-xylosidase in the culture medium of Aspergillus niger have been purified to homogeneity from 13- to 52-fold by a procedure of gel and hydroxylapatite chromatograp...
104 citations
01 Dec 1979
TL;DR: In this article, a production of macerating enzymes which liquefy and hydrolyze the mandarin orange peel was studied in a solid state cultivation of Aspergillus niger on wheat bran substrate.
Abstract: A production of macerating enzymes which liquefy and hydrolyze the mandarin orange peel was studied in a solid state cultivation of Aspergillus niger on wheat bran substrate. Solid state cultivation in a 2 l drum fermenter capable of interchangeable operation under dynamic or static conditions were carried out maintaining the moisture content of the substrate at 32, 39, 46, 56, 67, and 74%. Biomass grown on the solid substrate was estimated on the basis of a constant value of glucosamine content of A. niger, 50 mg glucosamine/g cell. A linear relationship between oxygen uptake rate and growth rate observed in all the experiments gave an oxygen growth yield, YX/O, of 28.5 g cell/mol O2. The rate of macerating enzyme formation was also in proportion to the growth rate irrespective of the difference of the moisture content of the substrate. The enzyme accumulation on the solid substrate, the growth rate and oxygen uptake rate were maximum when the moisture content of the substrate was maintained at ca. 56% ascending from 32 to 56 and descending from 56 to 74.
82 citations
TL;DR: Free amino acid pools have been investigated in a citric acid accumulating strain of Aspergillus niger during batch growth under manganese sufficient and deficient conditions by means of an improved chromatographic method and it was observed that theManganese deficient mycelia excreted high amounts of all amino acids suggesting that manganes deficiency may also affect membrane permeability.
Abstract: Free amino acid pools have been investigated in a citric acid accumulating strain of Aspergillus niger during batch growth under manganese sufficient and deficient conditions by means of an improved chromatographic method. Studies on the mycelial content of several nitrogenous compounds under manganese sufficient and deficient conditions showed that manganese deficiency resulted in lower amino acid pool sizes during trophophase and considerable accumulation during idiophase, and in a reduction of the protein and nucleic acid contents. Addition of cycloheximide to mycelia grown with sufficient manganese also caused an elevation of free amino acid pool sizes, thus indicating that impairment of protein synthesis by manganese deficiency is responsible for the observed rise in amino acid concentration. Furthermore it was observed that the manganese deficient mycelia excreted high amounts of all amino acids suggesting that manganese deficiency may also affect membrane permeability.
74 citations
TL;DR: The enzyme β-galactosidase from Aspergillus niger was purified and resolved into three multiple forms, using molecular sieving, ion-exchange, and hydrophobic chromatography, showing multiplicity was mainly due to dissimilar carbohydrate contents.
Abstract: The enzyme β-galactosidase (EC 32123) from Aspergillus niger was purified and resolved into three multiple forms, using molecular sieving, ion-exchange, and hydrophobic chromatography The isolated enzyme forms accounted for 83%, 8% and 9% of the total β-galactosidase activity, respectively They were glycoproteins with estimated molecular weights of 124000, 150000 and 173000, isoelectric points of about 46, and pH optima between 25 and 40 Amino acid and carbohydrate analyses showed that multiplicity was mainly due to dissimilar carbohydrate contents (about 125%, 205% and 29% neutral carbohydrates, respectively) The multiple form pattern might depend on the culture conditions
The β-galactosidase forms were heat-stable up to about 60°C The Km, values for lactose ranged from 85 mM to 125 mM, whereas those for the synthetic substrate o-nitrophenyl-β-d-galactopyranoside were equal to about 24 mM The V values obtained at 30°C for lactose and o-nitrophenyl-β-d-galactopyranoside were 104 units/mg enzyme protein and 121 units/mg enzyme protein, respectively (weighted averages for the three enzyme forms) The slight reactional dissimilarities between the three enzyme forms are unlikely to be physiologically relevant The biological significance of A nigerβ-galactosidase multiplicity might be related to the observed differences in carbohydrate content, as suggested by recent reports on other microbial glycoprotein enzymes
65 citations
59 citations
45 citations
TL;DR: The soil replica plating technique was used to evaluate the influence of clay minerals and pH on antagonistic interactions between fungi and bacteria in soil, and in general, the antagonistic activity of bacteria towards filamentous fungi was greater in soil than on agar.
Abstract: The soil replica plating technique was used to evaluate the influence of clay minerals and pH on antagonistic interactions between fungi and bacteria in soil. In general, the antagonistic activity of bacteria towards filamentous fungi was greater in soil than on agar. The spread of Aspergillus niger through soil was inhibited by Serratia marcescens when the organisms were inoculated into separate sites in soil, and this antagonistic effect was maintained when the soil was amended with 3, 6, 9, or 12% (vol/vol) montmorillonite, whereas the addition of kaolinite at a concentration of 3% reduced the antagonism and at 6, 9, or 12% totally eliminated it. Similar results were obtained with the inhibition of A. niger by Agrobacterium radiobacter and of Penicillium vermiculatum by either S. marcescens or Nocardia paraffinae. When A. niger and S. marcescens were inoculated into the same soil site, A. niger was inhibited in all soils, regardless of clay content, although the extent of inhibition was greater as the concentration of montmorillonite, but not of kaolinite, increased. A. niger was inhibited more when inoculated as spores than as mycelial fragments and when inoculated 96 h after S. marcescens, but a 1% glucose solution reduced the amount of inhibition when the fungus was inoculated 96 h after the bacterium. When the pH of the soil-clay mixtures was altered, the amount of antagonism usually increased as the pH increased. Antagonism appeared to be related to the cation-exchange capacity and the pH of the soil-clay mixtures. Bacillus cereus and another species of Bacillus showed no activity in soil towards A. niger under any of the environmental conditions tested, even though the Bacillus sp. significantly inhibited A. niger and seven other fungi on agar.
39 citations
38 citations
01 Sep 1979
TL;DR: Growth of Aspergillus niger and Cladosporium herbarum occurred in shake cultures with polyurethane as the sole nutrient source, though both fungi penetrated into the resilient foam tested.
Abstract: Growth of Aspergillus niger and Cladosporium herbarum occurred in shake cultures with polyurethane as the sole nutrient source. Simultaneously, the isocyanate almost completely disappeared from the polyurethane as determined with an IR-spectroscope. Otherwise, no structural changes were found in the polyurethane, though both fungi penetrated into the resilient foam tested.
37 citations
TL;DR: Several fungi isolated from decomposing wheat straw were tested for their ability to utilize whole straw and its components, holocellulose and cellulose, for the production of single-cell protein (SCP); it was found that C. specifer was the most efficient fungus for protein synthesis with the three substrates.
Abstract: Several fungi (Aspergillus niger, A. terreus, Cochliobolus specifer, Myrothecium verrucaria. Rhizoctonia solani, Spicaria fusispora. Penicillium sp., and Gliocladium sp.) were isolated from decomposing wheat straw and tested for their ability to utilize whole straw and its components, holocellulose (hemicellulose and cellulose) and cellulose, for the production of single-cell protein (SCP). It was found that C. specifer was the most efficient fungus for protein synthesis with the three substrates. Using potassium nitrate as N source in mixtures of 0.04 g N/g substrate (0.04% wt./vol.) at pH 4.5, it was found that incubation periods of 3. 4, and 5 days were optimal for protein production on cellulose and holocellulose fractions, and whole straw, respectively. Whole native straw was found to be the most recalcitrant to bioconversion into SCP; however, protein production was almost doubled when the lignin component was removed using a mixture of sodium chlorite and acetic acid.
TL;DR: Three fractions of A. fumigatus extract proved to be markedly specific for this species and cross reactivity was associated primarily with carbohydrate and glycoprotein fractions.
Abstract: Antigenic relationships between strains of Aspergillus fumigatus, Aspergillus fumigatus var. elipticus, Aspergillus phialiseptus, Aspergillus flavus, and Aspergillus niger were analyzed by fused rocket immunoelectrophoresis and by skin tests. Seventy-three to 89 % of the numbers of antigens detected between strains and species of the A. fumigatus series were shared. The degree of sharing between antigens of A. flavus, A. fumigatus series, and A. niger was much lower and ranged from 19 to 35 %. In reciprocal skin tests in sensitized guinea pigs, similar relationships were shown. Three fractions of A. fumigatus extract proved to be markedly specific for this species. Cross reactivity was associated primarily with carbohydrate and glycoprotein fractions.
Journal Article•
TL;DR: In this paper, homogeneous and heterogeneous biocatalysis tools for barley starch syrup production were investigated, and it was concluded that barley starch may be used as an alternative raw material for biOCatalytic starch syrup synthesis.
TL;DR: The respiratory rates of mycelia of the mesophilic fungus, Aspergillus niger, and the thermophobic fungus, Thermomyces lanuginosus, were comparable at their respective temperature optima for growth.
Abstract: The respiratory rates of mycelia of the mesophilic fungus, Aspergillus niger, and the thermophilic fungus, Thermomyces lanuginosus, were comparable at their respective temperature optima for growth The respiratory rate of A niger was independent of changes in temperature between 15 and 40 C The respiratory rate of T lanuginosus increased with increase in temperature between 25 and 55 C
TL;DR: The nature of thermophilic amylolytic enzymes produced by a strain of Aspergillus niger Van Tieghem was influenced by media composition, with deletion of the growth factors pyridoxine-hydrochloride and inositol suppressed enzyme production, while the absence of riboflavin had the opposite effect.
Abstract: The nature of thermophilic amylolytic enzymes produced by a strain of Aspergillus niger Van Tieghem was influenced by media composition. While glucose, maltose, dextrin and soluble starch induced the production of amyloglucosidase, pectin and sodium polypectate almost exclusively induced the formation of α-amylase. Alkali ions suppressed the formation of amyloglucosidase. NH4NO3, (NH4)2HPO4 and (NH4)2C4H4O6 served as good inorganic nitrogen sources, while casein, groundnut protein and corn steep liquor served to a similar capacity as nitrogen sources from organic material. Deletion of the growth factors pyridoxine-hydrochloride and inositol suppressed enzyme production, while the absence of riboflavin had the opposite effect.
TL;DR: In this paper, solid-substrate fermentations for extraction of protein from pressed alfalfa residues with Aspergillus Sp. QM 9994, Asgergillus niger QM 877, and Rhizopus nigricans QM 387 were conducted in shake flasks.
Abstract: Solid-substrate fermentations for extraction of protein from pressed alfalfa residues with Aspergillus Sp. QM 9994, Aspergillus niger QM 877, and Rhizopus nigricans QM 387 were conducted in shake flasks. Upon reimbibing and second pressing, total protein recovery from alfalfa was increased from 47.2% for control samples and up to 64.5% for fermented samples. Analysis of juice from fermented samples indicated the presence of cellulase as well as pectinase activities. Dialysis cultures of cellulase-producing fungi showed that total biomass production and solids consumption were much higher than those of a mutant strain lacking the ability to produce cellulase, indicating significant utilization of cellulosic materials in alfalfa. The biomass yields in the former case ranged from 39-47% based on total solids consumption. Since some of the cellulosic and other carbohydrate constituents in alfalfa may be converted into fungal protein, final alfalfa residues following protein extraction in a commercial process would be less bulky for storage and handling and would be more digestible as a nonruminant animal feed.
01 Dec 1979
TL;DR: The peel of the mandarin orange could be macerated by the crude enzymes produced by isolated A. niger and the test of the macerating activity of commercially available hydrolases on the orange peel showed that the two samples of pectinase originating from A.Niger had about the same activity as isolated Aspergillus niger.
Abstract: Thirty-nine fungal cultures belonging to the genera of Aspergillus, Podospora, Sordaria, Cbaetomium, Iodophanus, Scleotinia, Coniella, Pellicularia and others, were examined for the production of enzymes which macerate the mandarin orange peel using a wheat bran as substrate. An isolated strain of Aspergillus niger was an excellent producer of macerating enzymes compared to other organisms tested. The peel of the mandarin orange could be macerated by the crude enzymes produced by isolated A. niger. The maceration of 1 g of peel/24 h yielded 0.57 g of reducing sugars. Expressed differently, 83% of solid peel materials were released from the peel into the water/24 h under the following conditions: a peel concentration of 8 g peel/l, a crude enzyme concentration of 1 g protein/l, a temperature of 40°C, a pH of 5, a 24 h incubation time and 120 rpm reciprocal shaking. The test of the macerating activity of commercially available hydrolases on the orange peel showed that the two samples of pectinase originating from A. niger had about the same activity as isolated A. niger whereas the two samples of cellulase originating from Trichoderma viride had remarkably lower activities than A. niger.
TL;DR: The antibody covalently coupled to horseradish peroxidase (Ab-Px) was used as a probe to determine the cellular location of α-glu E by electron microscopic immunocytology and it was found on both sides of the plasma membrane (pm) and in the outer of the two layers of the cell wall.
TL;DR: The properties of a glucose oxidase from Aspergillus niger var.
Abstract: The properties of a glucose oxidase from Aspergillus niger var., immobilized by different methods were studied in a batch process. Dependencies between formation of gluconic acid and concentration of enzyme and glucose, supply with oxygen, pH-value and temperature were determined and the optimal parameters of reaction fixed. In this connexion consideration of the oxygen demand of the system was of special importance. Different “oxygen carriers” (pure oxygen, air, hydrogen peroxide) were used and their influences investigated not only on glucose oxidase but also on catalase, which is a conclusive fact in the reaction process. This led to very informative experiences on stability, re-usability and productivity of the carrier bound enzyme system. The results obtained should be applied to develop a continuous process for gluconic acid production and an enzyme preparation adapted to this process.
TL;DR: Normal spore germination showed the greatest susceptibility to inhibition, followed by conidiation, while giant cell formation was the least susceptible, and there was no apparent relationship between the amount of inhibitor added and the nature of the function inhibited.
Abstract: The effects of several metabolic inhibitors on normal spore germination and microcycle conidiation in Aspergillus niger van Teigh. were examined. Normal spore germination showed the greatest susceptibility to inhibition, followed by conidiation, while giant cell formation (vegetative growth) was the least susceptible. There was no apparent relationship between the amount of inhibitor added and the nature of the function inhibited.
TL;DR: A positive correlation (r = 0.77) between pH and the degree of autolysis was found and linear regression analysis indicated that the data were fitted by a line of slope 2.53 and an ordinate intercept of 41.83.
Abstract: The effect of pH on the degree of autolysis of cultures of Aspergillus niger autolysed at different pH values has been studied. In each experiment the fungus was grown in a chemically defined medium until autolysis commenced. At that time the pH was adjusted to values of 2, 4, 6, 8, or 10 and automatically controlled at that pH throughout the autolytic period. A positive correlation (r = 0.77) between pH and the degree of autolysis was found. Linear regression analysis indicated that the data were fitted by a line of slope 2.53 and an ordinate intercept of 41.83.
TL;DR: Thermostability of glucoamylase from Aspergillus niger is increased both by immobilization and substrate binding, but the total superimposed stabilization effect at a given condition is apparently restricted by a certain limit which hardly depends on the mode of immobilization.
Journal Article•
TL;DR: The results of re-incubation experiments with chitinase suggest that this enzyme may in some way be inhibited during the later stages of incubation, and this enzyme used in combination with beta-glucuronidase slightly enhanced protoplast release.
Abstract: The effects of beta-glucuronidase and chitinase have been tested on the hydrolysis of the cell walls of the economically important fungi, Aspergillus niger and Aspergillus fumigatus. The extent of wall hydrolysis was measured by assaying for total reducing sugars, N-acetyl sugars and protoplast production. Maximum reducing sugar release was attained after 40 min incubation, both with beta-glucuronidase supplemented with chitinase and beta-glucuronidase alone, whereas N-acetyl sugar release reached a maximum at 80 min incubation. beta-Glucuronidase was effective in releasing protoplasts from both species of Aspergillus. This release was enhanced by adding chitinase to the incubation medium at 0 and 20 min, but with addition at 60, 80 and 100 min increase in protoplast yield was much reduced. The results of re-incubation experiments with chitinase suggest that this enzyme may in some way be inhibited during the later stages of incubation. Pronase used in combination with beta-glucuronidase slightly enhanced protoplast release.
TL;DR: In this article, a 64-year-old man with a history of pulmonary tuberculosis, negative for M. tuberculosis, was found to have aspergilloma, colonization of the pulmonary cavity by A. niger and local oxalosis if the cavity wall.
Abstract: Haemoptysis occurred in a 64-year-old man with a history of pulmonary tuberculosis, negative for M. tuberculosis. Precipitating antibodies to Aspergillus niger were found in serum and the fungus found in sputum. Autopsy revealed aspergilloma, colonization of the pulmonary cavity by A. niger and local oxalosis if the cavity wall. Ornamental plant soil containing A. niger conidia, as well as the air in the patient's living-room, was the probable source of infection.
TL;DR: Autopsy revealed aspergilloma, colonization of the pulmonary cavity by A. niger and local oxalosis if the cavity wall in a 64-year-old man with a history of pulmonary tuberculosis, negative for M. tuberculosis.
Abstract: Haemoptysis occurred in a 64-year-old man with a history of pulmonary tuberculosis, negative for M. tuberculosis. Precipitating antibodies to Aspergillus niger were found in serum and the fungus found in sputum. Autopsy revealed aspergilloma, colonization of the pulmonary cavity by A. niger and local oxalosis if the cavity wall. Ornamental plant soil containing A. niger conidia, as well as the air in the patient's living-room, was the probable source of infection.