Showing papers on "Aspergillus niger published in 1976"
67 citations
01 Dec 1976
TL;DR: In this article, the degradation of aflatoxin B1 by Corynebacterium rubrum and Aspergillus niger was analysed by adding 14C-labeled aflat toxin B1 to cultures of these microorganisms.
Abstract: Degradation of aflatoxin B1 byCorynebacterium rubrum and byAspergillus niger was analysed by adding14C-labeled aflatoxin B1 to cultures of these microorganisms. Two blue fluorescent compounds, formed byA. niger from aflatoxin B1 with Rf-values 0.42 and 0.48 (Rf of aflatoxin B1=0.54) were accumulated and characterized by UV-, fluorescence and mass spectrometry. Based on their properties both products were identified to be aflatoxin Ro. Under the same conditionsMucor ambiguus andTrichoderma viride also produced aflatoxin Ro.
64 citations
TL;DR: A fungus capable of degrading DL-phenylalanine was isolated from the soil and identified as Aspergillus niger and it was found to metabolizeDL-phenYLalanine by a new pathway involving 4-hydroxymandelic acid.
Abstract: 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, which required reduced nicotinamide adenine dinucleotide phosphate, converted phenylacetic acid to 2- and 4-hydroxyphenylacetic acid. Although 4-hydroxyphenylacetate was converted to 4-hydroxymandelate, 2-hydroxyphenylacetate was not utilized until the onset of sporulation. During sporulation, it was converted rapidly into homogentisate and oxidized to ring-cleaved products. 4-Hydroxymandelate was degraded to protocatechuate via 4-hydroxybenzoylformate, 4-hydroxybenzaldehyde, and 4-hydroxybenzoate.
57 citations
TL;DR: Smith degradation, methylation, deamination, and optical rotation studies indicate that the galactosaminogalactan consists of a linear array of hexopyranosyl units joined almost exclusively by alpha-(1 leads to 4) linkages.
Abstract: A new heteropolysaccharide has been isolated by alkaline extraction of hyphal walls of Aspergillus niger NRRL 326 grown in surface culture. Its composition by weight, as determined by paper and gas chromatography and colorimetric analyses, is 70% galactose, 20% galactosamine, 6% glucose, and 1% acetyl. Two independent experiments have been used to ascertain copolymer structure: permeation chromatography in 6 M guanidinium hydrochloride, with controlled-pore glass columns of two fractionation ranges, and nitrous acid deaminative cleavage of galactosaminogalactan followed by reduction of fragments with [3H]borohydride and gel filtration chromatography. One of the tritiated fragments is tentatively identified as the disaccharide derivative galactopyranosyl 2,5-anhydrotalitol, on the basis of chromatographic properties and by kinetics of its acid hydrolysis. Smith degradation, methylation, deamination, and optical rotation studies indicate that the galactosaminogalactan consists of a linear array of hexopyranosyl units joined almost exclusively by alpha-(1 leads to 4) linkages. Hexosaminyl moieties are distributed randomly along the chains, which have an average degree of polymerization of about 100. The possible significance of this macromolecule in hyphal structure is considered.
55 citations
TL;DR: The excretion of the lytic enzymes β-N-acetyl-glucosaminidase, β -1–3 glucanase, chitinase, invertase and acid phosphatase into the culture medium during growth and autolysis was investigated and the excretion was consistent with the degree of Autolysis reached.
Abstract: 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.
53 citations
01 Jul 1976
TL;DR: An antifungal principle of the dried rhizomes of Curcuma zedoaria was extracted with hot ethanol and the structure of the most abundant one of these compounds was assigned as ethyl p-methoxycinnamate (EPMC), which inhibits the growth of Trichophyton rubrum.
Abstract: An antifungal principle of the dried rhizomes of Curcuma zedoaria was extracted with hot ethanol. By successive chromatography on neutral alumina and silica gel, three antibiotic compounds A, B, and C, all active against Trichophyton rubrum, Aspergillus niger and Saccharomyces cerevisiae, were obtained in chemically pure form. By uv, ir, pmr and ms analysis, the structure of the most abundant one of these compounds (C, 69.8%; H, 6,8%; and 0.23.4%) was assigned as ethyl p-methoxycinnamate (EPMC). The proposed structure was confirmed by synthesis and comparison of the chemical and biological properties of the natural and synthetic products. EPMC inhibits the growth of Trichophyton rubrum, Aspergillus niger, Saccharomyces cerevisiae and Epidermophyton floccosum at a concentration less than 10 mug/ml; A. fumigatus, Penicillium purpurogenum, Trignoposis variabilis, Microsporum gypseum, Sclerotium rolifsii, Geotricular candiade, Fusarium oxysporum and Helminthosporium oryzale at a concentration less than 25 mug/ml; and Candida krusei and T. mentagrophytes At a concentration less than 50 mug/ml. The spores of T. rubrum Lose viability or ability to germinate when wxposed to its ethanolic solution (30 mug/ml) for 2 hours.
44 citations
38 citations
TL;DR: The results suggest that zinc plays a role in the regulation of growth and citric acid accumulation and Iron, manganese, calcium at concentrations as high as 5-10 muM had no influence on either growth or citrate accumulation.
Abstract: The citric acid fermentation by Aspergillus niger is divided into two consecutive phases, a growth phase when the cells proliferate but do not accumulate citrate, followed by an accumulating phase when they produce citrate but do not proliferate, or else do so at a much reduced rate. When studied in a low sucrose (0.4-0.8%) mpinimal salts medium the growth-accumulation alternative was controlled by the concentration of zinc: high zinc (about 1-2 muM) maintained growth phase, while at low zinc (below 1 muM) growth became limited by zinc deficiency and the cultures passed into accumulating phase. Addition of zinc to accumulating cultures resulted in their reversion to growth phase. Iron, manganese, calcium at concentrations as high as 5-10 muM had no influence on either growth or citrate accumulation. These results suggest that zinc plays a role in the regulation of growth and citric acid accumulation.
37 citations
TL;DR: In this article, the action of glucoamylase I and II (α-1,4-glucan gluhydrolase, E.C. 3.2.3) from Aspergillus niger and the glu coamyl enzyme from Rhizopus niveus on native wheat and corn starch granules was followed by using scanning electron microscopy (SEM) and by measuring the glucose released by enzymatic attack.
Abstract: The action of glucoamylase I and II (α-1,4-glucan glucohydrolase, E.C. 3.2.1.3) from Aspergillus niger and the glucoamylase from Rhizopus niveus on native wheat and corn starch granules was followed by using scanning electron microscopy (SEM) and by measuring the glucose released by enzymatic attack. Two distinct patterns of attack were observed. Glucoamylase I and the glucoamylase from R. niveus attacked the granule surface relatively uniformly, resulting in large disclike depressions. Glucoamylase II, while showing some disc-like depressions, produced small grooves (furrows) in the surface of the granule. Similar patterns were observed for both corn and wheat starch granules, except that attack by glucoamylase I and the glucoamylase from R. niveus on wheat starch granules also developed along the equatorial groove (not easily seen until the granules were exposed to enzyme solutions). Measuring glucose released indicated that hydrolysis by glucoamylase I and by the glucoamylase from R. niveus were nearly equal in extent and were about twice that by glucoamylase II.
29 citations
Journal Article•
TL;DR: 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, and sucrose in an unautoclaved medium was found to be the best carbon source.
Abstract: 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 unautoclaved medium was found to be the best carbon source. Sucrose medium if autoclaved at pH 2.0, or a mixture of glucose and fructose instead of sucrose gave lower yields of citric acid. Under optimum conditions only citric acid was produced and the yield was 66-68 per litre after a growth period of about 10 days.
27 citations
TL;DR: Very few compounds alone or in combination could prevent growth of all three organisms and the only FDA approved additive that was effective alone was propylene glycol.
Abstract: Various microbial inhibitor systems were studied for their effectiveness in a semgmoist dog food formulation. The effectiveness was measured as inhibition of the natural contaminants Aspergillus glaucus and Staphylococcus epidermidis and of an inoculated challenge organism, Aspergillus niger. The study was carried out at aw 0.85 and 0.88 and at pH 5.4 and 6.3 giving a total of 108 systems. It was found that very few compounds alone or in combination could prevent growth of all three organisms. The only FDA approved additive that was effective alone was propylene glycol.
TL;DR: A comparative study on the mode of action of two highly purified acid endopeptidases from Aspergillus niger var.
TL;DR: A D-Galacturonanase catalyzing the degradation of D-galacturonans by terminal action pattern was purified from a culture filtrate of Aspergillus niger by a procedure including the salting-out with ammonium sulfate, precipitation by ethanol, chromatography on DEAE-cellulose, and gel chromatographyon Sephadex G-100.
TL;DR: 3 Phenylindole possibly interferes with phospholipid function in cell membranes, although the specific site of action has not yet been elucidated.
TL;DR: Bulk quantities of maize must be appraised on the basis of individual kernels because toxin-free kernels often are adjacent to highly contaminated kernels.
TL;DR: It is concluded that the active centre of glucoamylase I is a cleft lined with tryptophanyl residues that participate in the binding of the substrate and one or more carboxylic acid residues are involved in bond cleavage.
TL;DR: It is suggested that binding to phospholipids is the first effect of 3-phenylindole, and apparently this affects, consequently, several membrane-bound reactions, i.e., transport and biosynthetic processes.
TL;DR: A fermenter culture system is described for the production of enlarged spherical cells from the conidia of Aspergillus niger van Tiegh and ‘bursting’ of the spherical cells could be prevented by incubating the Conidia for 10 h at 41° then raising the temperature to 44° for a total time of 42 h.
Abstract: A fermenter culture system is described for the production of enlarged spherical cells from the conidia of Aspergillus niger van Tiegh In fermenter culture with synthetic medium maximum activation and spherical growth of the conidia could only be obtained by introducing 5 % CO2 into the gassing mixture At 41 °C the conidia underwent extensive spherical growth and in the presence of 5 % CO2 germ-tube formation from the enlarged cells was suppressed Maintenance of these conditions for more than 12 h induced ‘bursting’ and premature autolysis of the cells ‘Bursting’ of the spherical cells could be prevented by incubating the conidia for 10 h at 41° then raising the temperature to 44° for a total time of 42 h Analytical studies were carried out with respect to cell diameter cell volume, dry weight, glucose and ammonium uptake, pH, total carbohydrate, glycogen, trehalose, trehalase, DNA, RNA and protein
TL;DR: Ethyl 4-iodocrotonate was most toxic to the four fungi at pH 7.0 in the presence of 10% beef serum, and the mechanism of fungitoxicity is believed to be due, in part, to a nucleophilic reaction involving SH-containing compounds.
Abstract: Twenty-three 4-substituted crotonic acid esters were tested for antifungal activity against Candida albicans, Aspergillus niger, Mucor mucedo, and Trichophyton mentagrophytes. For the analogues of the methyl ester containing substituents in the 4 position, the following order of fungitoxicity was observed: I greater than Br greater than Cl greater than CH3S greater than CH3O greater than F=H. Of the homologues of the esters of the 4-iodo and 4-bromo compounds which included methyl, ethyl, n-propyl, n-butyl, n-pentyl, and n-hexyl, ethyl 4-iodocrotonate was most toxic to the four fungi at pH 7.0 in the presence of 10% beef serum (C. albicans, 18mug/ml, A. niger, 40 mug/ml, M. mucedo, 5 mug/ml, T. mentagrophytes, 4 mug/ml). It is believed that the mechanism of fungitoxicity is due, in part, to a nucleophilic reaction involving SH-containing compounds. This is based on the correlation of fungitoxicity with the order of leaving groups in the nucleophilic reaction and the protection against the toxicity of the test compounds to the fungi by cysteine and glutathione.
Patent•
10 Dec 1976
TL;DR: A broth medium for the detection of Candida yeasts, Saccharamyces cerevisiae, Torulopsis glabrata, and Aspergillus niger in urine is described in this article.
Abstract: A broth medium for the detection of Candida yeasts, Saccharamyces cerevisiae, Torulopsis glabrata, and Aspergillus niger in urine. The medium employs chloramphenicol and potassium tellurite to inhibit the growth of gram-positive and gram-negative organisms. The medium also uses reduced aniline blue biological pH indicator.
TL;DR: It was demonstrated that the affinity chromatography on omega-aminohexyl-Sepharose can be used as a powerful means of purifying this enzyme from crude extracts of Aspergillus niger.
TL;DR: This time, microbial transformation of dehydroepiandrosterone with Aspergillus niger was tried, and a new compound, 16β-hydroxy-4-androstene-3,17-dione, was obtained by the fermentation of 4-and frostene- 3, 17-Dione and testosterone.
Abstract: Microbial 16β-hydroxylation of some steroids with Wojnowicia graminis, Corticium centrifugum and Bacillus megaterium has been reported, but not 16β-hydroxylation of normal 17-oxo steroids with Aspergillus niger. This time, we tried microbial transformation of dehydroepiandrosterone with this fungus, and obtained 4-androstene-3,17-dione, 17β-hydroxy-4-androstene-3,16-dione, 16β,17β-dihydroxy-4-androsten-3-one and a new compound, 16β-hydroxy-4-androstene-3,17-dione. This new compound was also obtained by the fermentation of 4-androstene-3,17-dione and testosterone.
TL;DR: The pentachlorophenyl ester of benzo[b]-3-methyl-2-furancarbamic acid was the most active substance and the only compound to show antibacterial activity against Staphylococcus aureus.
Journal Article•
TL;DR: Tannase isolated from the culture medium of Aspergillus niger and purified gave a single band, suggesting that the carbohydrate-peptide linkage is of the O-glycoside type, involving mannose linked to threonine and serine.
Abstract: 1. Tannase (tannin acyl-hydrolase, EC 3.1.1.20) was isolated from the culture medium of Aspergillus niger and purified about 200-fold. On polyacrylamide-gel electrophoresis it gave a single band. 2. The molecular weight of the enzyme was of the order of 55 000 as determined by gel filtration. The enzyme contains 21.5% of carbohydrates (mannose and glucose). 3. Treatment of tannase with alkaline borohydride decreased the content of threonine, serine and mannose, suggesting that the carbohydrate-peptide linkage is of the O-glycoside type, involving mannose linked to threonine and serine.
Patent•
24 May 1976
TL;DR: In this paper, the authors describe the production of the antibiotic lucknomycin by culturing Streptomyces diastatochromogenes var. Krains in an aqueous nutrient medium under submerged aerobic conditions.
Abstract: Antifungal and antiprotozoal antibiotic lucknomycin is producible by culturing Streptomyces diastatochromogenes var. Krains in an aqueous nutrient medium under submerged aerobic conditions. Lucknomycin is active against Candida albicans, Candida tropicalis, Candida krusei, Aspergillus niger and more particularly against Trichomonas vaginalis.
TL;DR: The biotransformation, time dependent changes of metabolites and differences of the mode of metabolism among five fungi, which were all isolated from the soil of rice field treated with o-sec-buthylpenyl N-methylcarbamate (BPMC) (I) were investigated using 3H- BPMC.
Abstract: The biotransformation, time dependent changes of metabolites and differences of the mode of metabolism among five fungi, which were all isolated from the soil of rice field treated with o-sec-buthylpenyl N-methylcarbamate (BPMC) (I) were investigated using 3H-BPMC. In every fungus used in the present study, a common metabolic pathway was that through hydroxylation at the alkyl side-chain. The metabolic breakdown of I by A. niger reached the maximum at 2 or 3 days cultivation and hydroxylation at alkyl side-chain of I was attained at the early stage of cultivation. Remarkable differences have been shown to exist among the various species as to formation of metabolites.
TL;DR: Repeated experiments showed that, although mutagenic reatment of the wild type culture did produce strains with slightly higher yields of citric acid, no single strain could produce a strain with an appreciable improvement of productivi ty in cane molasses medium, so efforts were made to obtain a strain through a stepwise induction of mutat ions contributing to higher yield.
Abstract: The importance of mutational improvement of industrial microorganisms has been well emphasized (Alikhanian, 1962; Calam, 1964, 1970). Variations in growth conditions as well as the composition of fermentable raw materials often warrant the selection of new strains of the organisms concerned for the desired yields (Thoma, 1971). Mutagenic techniques have been employed successfully in Aspergillus niger for enhancement of citric acid product ivi ty (Das and Nandi, 1969; Sauchez-Marroquin et al., 1970). A number of radiation induced mutants of Aspergillus niger were found to show a remarkable increase in citric acid production in sucrose solution (Hannah et al., 1973). However, such mutants exhibited very poor performance in fermentation medium prepared with cane molasses as carbon source. Our repeated experiments showed that , although mutagenic t reatment of the wild type culture did produce strains with slightly higher yields of citric acid, no single t rea tment could produce a strain with an appreciable improvement of productivi ty in cane molasses medium. Fur ther a t tempts were therefore made to obtain such a strain through a stepwise induction of mutat ions contributing to higher yield. Gamma-irradiation (Co 60 source) was used for mutagenic t reatments in all experiments. The wild type strain, CA16, and the methods of growth and maintenance of cultures, mutagenic t reatments and selection of new strains, and estimations of total sugar, total acid and citric acid in fermentation medium were the same as those described earlier (Hannah, 1972; Hannan et al., 1973). In the present study, however, crude cane molasses, diluted with distilled water to contain 10--14% total sugar, were used as carbon source in the fermentation medium. The inorganic salts were the same as those used by Doelger and Prescott (1934), and the initial p H of the medium was adjusted to 3.5 with 1M HC1. Fermentat ion was run for 7-9 days at 30 i 1 ~ and then the medium fermented by each strain was assayed. Citric acid yield was determined as percent o f the total sugar initially present in the medium (w/w). The results achieved are briefly presented in Fig. 1 showing the stepwise development of high yielding strains. I t can be seen that the wild type isolate, CA16 was able to show only about 15% yield of citric acid in cane molasses while the
TL;DR: In all sixty two new fluorinated heterocyclic compounds have been prepared as mentioned in this paper, out of which thirty six were screened against Aspergillus niger and aspergilli flavus for their antifungal activity.
Abstract: 2-Arylamino-4-fluoroarylthiazoles have been synthesized by the condensation of fluoroke-tones with arylthioureas in presence of iodine. The resulting compounds were mercurated with mercuric acetate. 2-Arylideneamino-4-fluoroarylthiazoles and 2-arylsulfonamido-4-fluoroaryl-5-H/alkyl thiazoles have been synthesised by the condensation of 2-amino-4-fluoro-aryl-5-H/alkylthiazoles with aldehydes and halogenated benzenesulfonyl chlorides respectively. 2-Acetamido-4-fluoroaryl-5-aryloxythiazoles have been synthesized from 2-acetamido-4-fluoroaryl-5-bromothiazoles and sodium salts of phenols. In all sixty two new fluorinated heterocyclic compounds have been prepared. Out of these thirty six were screened against Aspergillus niger and Aspergillus flavus for their antifungal activity. Most of them showed promising results.
Journal Article•
TL;DR: Of a number of other micro-organisms tested, Pseudomonas sp.
Abstract: The yeasts Saccharomyces and Rhodotorula were grown on spent lucerne whey under continuous culture and other culture conditions; cell yield was 5–6 g/1. The amount of protein and amino acids remaining in the whey after fermentation was determined as a means of checking the ability of these yeasts to scavenge this “amino acid fraction” from the whey. Saccharomyces in continuous culture gave the greater depletion of 2.8 g/1, which was improved by the addition of carbohydrate to 3.7 g/1. These figures were, however, only 50% of the total amino acid fraction in the whey. Of a number of other micro-organisms tested, Pseudomonas sp. and Aspergillus niger showed the most promise, but neither were as convenient as the yeasts.