Showing papers on "Aspergillus niger published in 1972"
TL;DR: Green-spored strains of Aspergillus nidulans contain a p-diphenol oxidase (laccase) which is only formed during sporulation and is absent from yellow-sporing mutants, while indirect evidence suggests that the enzyme also contains copper.
Abstract: SUMMARY: Green-spored strains of Aspergillus nidulans contain a p-diphenol oxidase (laccase) which is only formed during sporulation and is absent from yellow-spored mutants. The enzyme was assayed colorimetrically using N,N-dimethyl-p-phenylenediamine as substrate. Other substrates oxidized were pyrogallol, gallic acid and 2,6-dimethoxyphenol. Quinol, catechol and p-cresol were not detectably oxidized. Experiments with a temperature-sensitive yellow-spored mutant showed that the yA locus of A. nidulans is a structural gene for at least a component of the enzyme, while indirect evidence suggests that the enzyme also contains copper. Yellow-green-spored mutants of the ygA locus produce an inactive enzyme whose activity can be restored by dialysis against copper salts. Under certain conditions the enzyme itself can diffuse from a wild-type colony to a yellow-spored mutant colony and there act to give green spore pigment. From this it is deduced that the normal site of action of the enzyme may be external to the cell membrane. A similar enzyme has also been found in conidiating cultures of Aspergillus niger and Penicillium brevicompactum.
180 citations
TL;DR: The detailed specificity studies indicate that it is highly specific for nonreducing terminal l-fucose residues linked to d-galactose residues by 1 → 2-α linkage, and extremely active against human blood group substance H, destroying virtually all of the detectable activity.
98 citations
76 citations
TL;DR: Exogenous carbon and nitrogen sources were necessary for complete swelling (spherical growth) and germ-tube formation from Aspergillus niger spores and under conditions of spore crowding an inhibition became apparent which affec...
Abstract: Exogenous carbon and nitrogen sources were necessary for complete swelling (spherical growth) and germ-tube formation from Aspergillus niger spores. The rate of spherical growth was low at 30°, max...
61 citations
TL;DR: The induction of glucoamylase by maltose was independent of sulfate concentration but showed a dependency on low pH and the absence of utilizable carbon sources.
Abstract: Low levels of glucoamylase are produced when Aspergillus niger is grown on sorbitol, but substitution of the latter by glucose, maltose, or starch results in greater formation of glucoamylase as measured by enzymatic activity. Both glucoamylase I and glucoamylase II are formed in a yeast extract medium; however, glucoamylase I appears to be the only form produced when ammonium chloride is the nitrogen source. Maltose or isomaltose (1.4 × 10−4m), but no other disaccharides or monosaccharides, dextrins, dextrans, or starches, stimulated glucoamylase formation when added to mycelia pregrown on sorbitol-ammonium salts. The induction of glucoamylase by maltose was independent of sulfate concentration but showed a dependency on low pH and the absence of utilizable carbon sources.
55 citations
TL;DR: A chromatographic method for endopolygalacturonase purification was developed based on observations made during incubation of a mixture of extracellular pectolytic enzymes of Aspergillus niger with insoluble pectic acid cross-linked by epichlorhydrine.
53 citations
TL;DR: Pullulan 4-glucanohydrolase, a novel pullulan-hydrolyzing enzyme from Aspergillus niger, was highly purified by means of acetone precipitation, chromatography on P-cellulose and DEAE- cellulose, and gel filtration on Sephadex G-150.
48 citations
TL;DR: Calculated Km values for the free and bound enzymes with lactose as the substrate were comparable; however, the V of the bound enzyme was decreased by 60%.
48 citations
TL;DR: A 100-fold purified preparation of Aspergillus niger α-mannosidase free of α- and β-galactosidases, β-N-acetylglucosaminidase, and 1,2-α-mannOSidase has been obtained and hydrolyzes specific intersugar linkages involving nonreducing terminal mannose residues in large as well as small molecules.
42 citations
TL;DR: The structure of a fungal (1→3)-α- d -glucan, pseudonigeran (DP 330, [α] d 25 +252° in m sodium hydroxide), has been investigated by methylation, periodate oxidation, and partial acid hydrolysis.
36 citations
TL;DR: It is considered that the TCA cycle may be fully operational during citric acid production, as intermediates of the tricarboxylic acid (TCA) cycle were oxidized by these mitochondria.
Abstract: Tightly coupled mitochondria were isolated from Aspergillus niger during citric acid production. Intermediates of the tricarboxylic acid (TCA) cycle and reduced nicotinamide adenine dinucleotide (NADH) were oxidized by these mitochondria. Certain enzymes of the TCA cycle, condensing enzyme, aconitase, succinic dehydrogenase, fumarase, NAD-and NADP-linked isocitric dehydrogenase and malic dehydrogenase, were isolated at different stages of the citric acid fermentation. The activities of two enzymes of the glyoxylate cycle, isocitrate lyase and malate synthetase, were also assayed. All enzymes were functioning and there were no significant differences in activities during the citric acid fermentation. Thus it is considered that the TCA cycle may be fully operational during citric acid production.
TL;DR: Gases from cultures of a strain of Trichoderma harzianum Rifai inhibit growth and sporulation of Aspergillus niger and of Pestalotia rhododendri, and the coloration and rate of elongation of seedlings of Lactuca sativa var.
Abstract: Gases from cultures of a strain of Trichoderma harzianum Rifai inhibit growth and sporulation of Aspergillus niger and of Pestalotia rhododendri , and the coloration and rate of elongation of seedlings of Lactuca sativa var. sativa . The effects can be attributed to the amounts of carbon dioxide and ethanol formed by T. harzianum in the test conditions. Strains of Bacillus subtilis, Klebsiella aerogenes, Pseudomonas pyocyaneus, Staphylococcus aureus and Sarcina lutea were not inhibited by the culture gases.
TL;DR: Observations are interpreted as evidence that the thallus of A. niger contains a mannose transferase that uses the phosphate of exo-methylene-hexahydropolyprenol phosphate as an acceptor in the biosynthesis of bacterial wall mannan.
Abstract: Growth of Aspergillus niger in the presence of [2-(14)C]mevalonate and (32)P(i) led to the formation of a lipid, containing (14)C (0.14% of dose) and (32)P (0.009% of dose), that had chromatographic properties identical with those of exo-methylene-hexahydropolyprenol phosphate. When a particulate enzyme preparation from the thallus of A. niger was incubated with GDP-[(14)C]mannose, the main radioactive products were mannose 1-phosphate (57% of products) and mannose (18%). In addition radioactive mannan (8%) and a mannolipid (2%) were formed. The latter was identified as exo-methylene-hexahydropolyprenol phosphate mannose on the basis of its chromatographic properties, acid lability and on the increase in formation of the mannolipid when the phosphate of exo-methylene-hexahydropolyprenols was added to the incubation mixture. The phosphates of ficaprenols and cetyl alcohol caused no corresponding increase. These observations are interpreted as evidence that the thallus of A. niger contains a mannose transferase that uses the phosphate of exo-methylene-hexahydropolyprenols as an acceptor. This situation is discussed in the light of the analogous involvement of a prenol phosphate mannose as an intermediate in the biosynthesis of bacterial wall mannan.
TL;DR: The disaccharide has been synthesized by the condensation of α-acetobromomannose with 1,3,4,6-tetra-O-acetyl-d-mannose followed by deacetylation of the resulting product, which shows a pH optimum of 4.8 and is stable in the pH range of 5.0 to 8.0.
TL;DR: The interrelations of the momentary concentrations of the intermediates indicated that the phosphofructokinase step may be a control site in glycolysis in Aspergillus niger.
Abstract: Fluorometric methods have been used for the determination of the momentary levels of some glycolytic intermediates and adenylates during the development of Aspergillus niger in fermenter culture and also in a medium which allows vegetative growth but not conidiation. During periods of active glycolysis the levels of the hexose monophosphates were low while the other intermediates were high; during periods of low glycolysis this pattern was reversed. The interrelations of the momentary concentrations of the intermediates indicated that the phosphofructokinase step may be a control site in glycolysis in Aspergillus niger.
TL;DR: Details of the appearance of the virus particles within the infected yeast cells as determined by electron microscopy are given.
Abstract: LHOAS1 has demonstrated the infection of mating pairs of Saccharomyces cerevisiae with double stranded RNA viruses from Aspergillus niger and Penicillium stoloniferum (preceding communication). I wish to give details of the appearance of the virus particles within the infected yeast cells as determined by electron microscopy.
TL;DR: The sulfoxidation of p-thioanisidine by mammals is a microsomal mixed function oxidation, which is not stereospecific and both stereoselective reactions seem to be the cause of the formation of optically active sulfoxides in vivo.
TL;DR: A causal relationship between a biochemical event and a morphological character in a fungus has been firmly established and Aspergillus niger was observed to have a low basal esterase activity.
Abstract: Esterase activity was induced in Aspergillus niger only during conidiation and not in sterile cultures, irrespective of the source of nitrogen for growth. The increase in esterase activity during conidiation was observed cytochemically to occur in the conidiophore tip prior to the formation of the vesicle and phialides and in the latter structures after their formation. Electrophoresis of cell-free extracts of conidiating mycelia revealed a multimolecular esterase profile; with one exception (this only contained one band and was therefore unimolecular) no esterase profile was obtained from sterile cultures although such extracts contained a low basal esterase activity. In this study a causal relationship between a biochemical event and a morphological character in a fungus has been firmly established.
TL;DR: 2-Methyl-8-quinolinol and sixteen 5-, 7-, and 5,7-substituted derivatives with fluoro, chloro, bromo, iodo, nitro, and amino substituents were tested for in vitro antifungal activity against five fungi.
Abstract: 2-Methyl-8-quinolinol and sixteen 5-, 7-, and 5,7-substituted derivatives with fluoro, chloro, bromo, iodo, nitro, and amino substituents were tested for in vitro antifungal activity against five fungi, Aspergillus niger, A. oryzae, Trichoderma viride, Myrothecium verrucaria , and Trichophyton mentagrophytes . The 5,7-dichloro and 5,7-dibromo derivatives were the most fungitoxic of the compounds tested. With the exception of these two compounds and 5-iodo-2-methyl-8-quinolinol, the 2-methyl analogues were less active than the corresponding 8-quinolinols.
Journal Article•
Journal Article•
TL;DR: The lipids from conidia of Aspergillus niger were extracted and identified, and freeze-etched replicas of dormant conidia revealed the presence of lipid bodies.
Abstract: The lipids from conidia of Aspergillus niger were extracted and identified. The polar lipid content was higher (54.3%) than the neutral lipid fraction (45.7%). The major fatty acids present were C1...
TL;DR: Comparisons between A. niger and T. viride suggest that the faster the swelling rate of a spore, the more resistant that spore will be to changes in the physical and chemical environment.
Abstract: Swelling curves obtained from Coulter counter data show the influence of temperature and media, and the effects of the pharmaceutical preservative methyl p-hydroxybenzoate on spore swelling of Aspergillus niger van Tieghem and Trichoderma viride Pers. ex Fr. The optimal temperature for linear growth was lower than that for spore swelling. Comparisons between A. niger and T. viride suggest that the faster the swelling rate of a spore, the more resistant that spore will be to changes in the physical and chemical environment.
TL;DR: Analysis of the superior substrains showed gamma irradiation to be most effective in producing the greatest number of superior mutants.
Abstract: Aspergillus niger C was treated with UV and gamma irradiation (60Co), nitrogen mustard and colchicine. Mutagenic treatments resulted in substrains with either increased or decreased citric acid production, while some were unchanged in this respect. Low-yielding strains predominated in all the experiments. Analysis of the superior substrains showed gamma irradiation to be most effective in producing the greatest number of superior mutants.
Patent•
02 May 1972
TL;DR: In this paper, the authors present a new ANTIVIRAL SUBSTance that has been found to be effective against BOTH DNA and RNA VIRUSES is LABORATORY ANIMALS.
Abstract: THE PRESENT INVENTION RELATES TO A NEW ANTIVIRAL SUBSTANCE. MORE PARTICULARLY, THE PRESENT INVENTION RELATES TO A NEW ANTIVIRAL SUBSTANCE OBTAINED FROM A FERMENTATION PROCESS UTILIZING A NOVEL MICROORGANISM OF THE SPECIES ASPERGILLUS NIGER. THE ANTIVIRAL SUBSTANCE HAS BEEN FOUND TO BE EFFECTIVE AGAINST BOTH DNA AND RNA VIRUSES IS LABORATORY ANIMALS.