Showing papers on "Aspergillus niger published in 2006"
Journal Article•
TL;DR: Gluconic acid is a mild organic acid derived from glucose by a simple oxidation reaction, the principal being sodium gluconate, which has wide applications in food and pharmaceutical industry.
Abstract: Summary Gluconic acid is a mild organic acid derived from glucose by a simple oxidation reaction. The reaction is facilitated by the enzyme glucose oxidase (fungi) and glucose dehydrogenase (bacteria such as Gluconobacter). Microbial production of gluconic acid is the preferred method and it dates back to several decades. The most studied and widely used fermentation process involves the fungus Aspergillus niger. Gluconic acid and its derivatives, the principal being sodium gluconate, have wide applications in food and pharmaceutical industry. This article gives a review of microbial gluconic acid production, its properties and applications.
490 citations
TL;DR: It is concluded that the essential oils from Thymus eriocalyx and T. x-porlock could be safely used as preservatives and showed irreversible damage to cell wall, cell membrane and cellular organelles.
234 citations
TL;DR: Five essential oils demonstrated marked inhibitory effect against hyphal growth and spore formation of Aspergillus niger, suggesting their use as strong aroma therapeutic agents.
Abstract: Aspergillus niger is an opportunistic human pathogen and a strong air pollutant. A study was conducted with 75 different essential oils for the inhibition of hyphal growth and spore formation in Aspergillus niger. Cinnamomum zeylanicum (bark), Cinnamomum zeylanicum (leaf), Cinnamomum cassia, Syzygium aromaticum and Cymbopogon citratus were the top five essential oils which demonstrated marked inhibitory effect against hyphal growth and spore formation of A. niger. The chemical composition of these five most active essential oils was investigated by gas chromatography-mass spectra (GC-MS). Most of the other essential oils were found challenging to combat A. niger, suggesting their use as strong aroma therapeutic agents.
218 citations
TL;DR: The rich amount of data resulting from these multiple A. niger genome sequences will be used for basic and applied research programs applicable to fermentation process development, morphology and pathogenicity.
Abstract: Aspergillus niger is a filamentous ascomycete fungus that is ubiquitous in the environment and has been implicated in opportunistic infections of humans. In addition to its role as an opportunistic human pathogen, A. niger is economically important as a fermentation organism used for the production of citric acid. Industrial citric acid production by A. niger represents one of the most efficient, highest yield bioprocesses in use currently by industry. The genome size of A. niger is estimated to be between 35.5 and 38.5 megabases (Mb) divided among eight chromosomes/linkage groups that vary in size from 3.5-6.6 Mb. Currently, there are three independent A. niger genome projects, an indication of the economic importance of this organism. The rich amount of data resulting from these multiple A. niger genome sequences will be used for basic and applied research programs applicable to fermentation process development, morphology and pathogenicity.
213 citations
TL;DR: The antimicrobial results of this study correspond positively with the claimed ethnomedical uses of the leaves of Vernonia amygdalina in the treatment of various infectious diseases.
199 citations
TL;DR: Findings indicate that A. tubingensis is able to produce ochratoxin and that, together with A. carbonarius and A. niger, it may be responsible for the ochRatoxin contamination of wine in Italy.
Abstract: Ochratoxin A is a potent nephrotoxin and a possible human carcinogen that can contaminate various agricultural products, including grapes and wine. The capabilities of species other than Aspergillus carbonarius within Aspergillus section Nigri to produce ochratoxin A from grapes are uncertain, since strain identification is based primarily on morphological traits. We used amplified fragment length polymorphisms (AFLPs) and genomic DNA sequences (rRNA, calmodulin, and -tubulin genes) to identify 77 black aspergilli isolated from grape berries collected in a 2-year survey in 16 vineyards throughout Italy. Four main clusters were distinguished, and they shared an AFLP similarity of <25%. Twenty-two of 23 strains of A. carbonarius produced ochratoxin A (6 to 7,500 g/liter), 5 of 20 strains of A. tubingensis produced ochratoxin A (4 to 130 g/liter), 3 of 15 strains of A. niger produced ochratoxin A (250 to 360 g/liter), and none of the 19 strains of Aspergillus “uniseriate” produced ochratoxin A above the level of detection (4 g/liter). These findings indicate that A. tubingensis is able to produce ochratoxin and that, together with A. carbonarius and A. niger, it may be responsible for the ochratoxin contamination of wine in Italy. Ochratoxin A (OTA) is an important mycotoxin; is considered to be nephrotoxic, immunotoxic, genotoxic, and teratogenic; and has been classified by the International Agency for Research on Cancer as a possible human carcinogen (group
190 citations
TL;DR: Urea as a nitrogen source and pH 5.0 were found to be optimal for growth and cellulase production by Aspergillus niger and carboxymethylcellulose and sawdust at 1% supported maximum production of all three enzymes by A.niger.
Abstract: The production of cellulase (filter paper activity, endoglucanase and )-glucosidase) by Aspergillus niger on three media in liquid shake culture was compared. The culture filtrate of this organism exhibited relatively highest activity of all three enzymes and extracellular protein content at 7-day interval during the course of its growth on Czapek-Dox medium supplemented with 1.0% (w/v) cellulose. Urea as a nitrogen source and pH 5.0 were found to be optimal for growth and cellulase production by A.niger . Among various soluble organic carbon sources and lignocelluloses tested in this study, carboxymethylcellulose and sawdust at 1% supported maximum production of all three enzymes by A.niger . Keywords: Aspergillus niger , cellulase activity, nutrients, 6-glucosidase
185 citations
TL;DR: In vitro toxicity tests demonstrated that compounds 4d and 6a showed very less toxicity against human erythrocytes, and all synthesized compounds showed significant activity against bacterial strains but were found to be less active against tested fungi.
162 citations
TL;DR: Non-viable fungal biomass of Aspergillus niger, coated with iron oxide was investigated for its potential to remove arsenic from an aqueous solution and no strong relationship was observed between the surface charge of the biomass and arsenic removal.
158 citations
TL;DR: Two purified feruloyl esterases from Aspergillus niger, FAEA and FAEB were tested for their ability to release phenolic acids from coffee pulp, apple marc and wheat straw and show the ability of these enzymes to hydrolyze quinic esters and ester linkages between phenolic acid and lignin monomer.
155 citations
TL;DR: In this article, Aspergillus niger was applied to four agro-industrial wastes as substrates for microbial solubilization of rock phosphate (RP), including sugar beet wastes (SB), olive cake (OC), and olive mill wastewaters (OMWW).
Abstract: Four agro-industrial wastes were assayed as substrates for microbial solubilization of rock phosphate (RP). Sugar beet wastes (SB), olive cake (OC) and olive mill wastewaters (OMWW) were treated by Aspergillus niger, and dry olive cake (DOC) was treated by Phanerochaete chrysosporium. In conditions of solid-state fermentation 46% of SB and 21% of OC were mineralized by A. niger while 16% of DOC was mineralized by P. chrysosporium. Repeated-batch mode of fermentation was employed for treatment of OMWW by immobilized A. niger, which resulted in conversion of 80% of the fermentable sugars. Acidification of all media treated by A. niger was registered with a simultaneous solubilization of 59.7% (SB), 42.6% (OC), and 36.4% (OMWW) of the total P present in the RP. The same mechanism of RP solubilization was observed in DOC-based medium inoculated with P. chrysosporium but other mechanisms were probably involved during the process. A series of microcosm experiments were then performed in the greenhouse to evaluate the effectiveness of the resulting fermented products. All amendments improved plant growth and P acquisition, which were further enhanced by mycorrhizal inoculation. The level of all studied parameters including the root mycorrhizal colonization depended on the substrate characteristics. The reported biotechnological schemes offer a potential application particularly for degraded soils.
TL;DR: In this paper, the authors used the Plackett-burman design for the optimization of α-amylase (E.C. 16404) from Aspergillus niger ATCC 16404 fungus.
Journal Article•
TL;DR: Lipase production in Aspergillus niger J-1 was tested using both submerged fermentation (SmF) and solid-state fermentation (SSF) on a mineral culture medium and wheat bran, respectively and the optimization of the culture medium was carried out for both SmF and SSF.
Abstract: Summary Lipase production in Aspergillus niger J-1 was tested using both submerged fermentation (SmF) and solid-state fermentation (SSF) on a mineral culture medium and wheat bran, respectively. The optimization of the culture medium was carried out for both SmF and SSF. The maximum lipase activity, 1.46 IU/mL, was obtained during the submerged fermentation in a medium containing glucose at 2 % and olive oil at 2 % under conditions of 1 vvm and 450 m –1 . However, 9.14 IU/g of dry solid substrate equivalent to 4.8 IU/mL of lipase activity was reached using solid-state fermentation process with a medium containing 0.75 % of ammonium sulphate and 0.34 % of urea. The optimum pH and temperature for enzymatic activity were pH=6 and 40 °C, respectively. The enzyme also exhibited 80 % of its initial activity in neutral and mildly acid media and at temperatures between 20 and 30 °C for a period of 24 hours.
TL;DR: Detailed surveys of Australian wines have determined that the frequency and level of OTA contamination are low, and Bentonite in white wine and yeast hulls in red wine were the most effective non-carbonaceous fining agents for the removal of Ota.
TL;DR: There is a wide range of biotechnological applications for amylases, including the textile, pharmaceutical, food and laundry industries, and the potential uses of this enzyme in detergents, different formulations were tested using the A. niger amylase extract.
TL;DR: In this article, the synthesis of amylase and protease by Aspergillus niger strain UO-1 was followed in media prepared with brewery ( BW) and meat (MPW) wastewaters supplemented with different starch concentrations.
TL;DR: Thiazolidin-4-ones 3c, 3j, 3g, 3d, and 3e showed potent antimicrobial activity, when compared to standard drugs, according to the single crystal X-ray diffraction method.
TL;DR: Data about the inhibition effect of ethylenediaminetetraacetic acid and phenylmethanesulfonyl fluoride on the involved hydrolytic enzymes showed that enzymes involved in ochratoxin A hydrolysis are metalloproteins.
Abstract: Ochratoxin A is a mycotoxin present in food commodities as cereals, wine, coffee, figs, dried vine fruits or beer and in feeds for animals. The enhancement of its conversion into ochratoxin α is considered to be a way to reduce its presence in the body and, therefore, its toxicity. In this paper we report the ability of several commercial proteases to hydrolyze ochratoxin A into ochratoxin α in different amounts. After an incubation period of 25 h., a significant hydrolytic activity at pH 7.5 for Protease A (87.3%), and for Pancreatin (43.4%) was detected. At pH 3.0, a weak hydrolytic activity was detected for Prolyve PAC (3%). None of the other commercial enzymes tested were able to hydrolyze ochratoxin A in the tested conditions. Also, the isolation of an enzyme extract from an Aspergillus niger strain with very strong ochratoxin A hydrolytic activity at pH 7.5 (99.8%) is reported. This activity is similar to the activity detected in Protease A. Data about the inhibition effect of ethylenediaminetetraac...
TL;DR: Studies were carried out on the production of pectinases using deseeded sunflower head by Aspergillus niger DMF 27 and DMF 45 in submerged fermentation (SmF) and solid-state fermentation (SSF); higher titres of endo- and exo-pectinases were observed when medium was supplemented with carbon and nitrogen.
TL;DR: The study suggests that choosing an appropriate substrate when coupled with process level optimization improves enzyme production markedly and developing an asparaginase production process based on bran of G. max as a substrate in SSF is economically attractive as it is a cheap and readily available raw material in agriculture-based countries.
Abstract: This article reports the production of high levels of L-asparaginase from a new isolate of Aspergillus niger in solid state fermentation (SSF) using agro-wastes from three leguminous crops (bran of Cajanus cajan, Phaseolus mungo, and Glycine max). When used as the sole source for growth in SSF, bran of G. max showed maximum enzyme production followed by that of P. mungo and C. cajan. A 96-h fermentation time under aerobic condition with moisture content of 70%, 30 min of cooking time and 1205-1405 micro range of particle size in SSF appeared optimal for enzyme production. Enzyme yield was maximum (40.9 +/- 3.35 U/g of dry substrate) at pH 6.5 and temperature 30 +/- 2 degrees C. The optimum temperature and pH for enzyme activity were 40 degrees C and 6.5, respectively. The study suggests that choosing an appropriate substrate when coupled with process level optimization improves enzyme production markedly. Developing an asparaginase production process based on bran of G. max as a substrate in SSF is economically attractive as it is a cheap and readily available raw material in agriculture-based countries.
TL;DR: Remarkable differences in the morphology of A. niger and dry cell weight between SM and GM were observed, and the difference in morphology may have caused a reduction of oxygen transfer, resulting in a decrease in gluconic acid production rate in SM.
TL;DR: Aspergillus niger isolated from soil of leather tanning effluent had higher activity to remove chromium then the other fungal isolates as mentioned in this paper and was evaluated in shake flask culture by absorption of chromium at pH 6, temperature 30°C.
Abstract: Aspergillus niger isolated from soil of leather tanning effluent had higher activity to remove chromium then the other fungal isolates. The potency of A. niger was evaluated in shake flask culture by absorption of chromium at pH 6, temperature 30 °C. The toxicity of chromium evaluated in petriplates and soil microcosm seed bioassay test had indicated increase in toxicity with the higher concentration of chromate. A. niger introduced in soil microcosm (40% moisture content) with different concentration of chromate (250, 500, 1000, 1500 and 2000 ppm) removed more than 70% chromium in soil contaminated by 250 and 500 ppm of chromate. However, chromium-contaminated soil (2000 ppm of potassium chromate) mixed with compost (5% and 10%) significantly removed chromium in presence of fungus, A. niger. The results of chromate toxicity in the wheat plants revealed that the peroxidases was induced due to increase of metal stress which was reversed in soil microcosm amended with compost.
TL;DR: The antimicrobial activities of pigment derivatives are considered to be related to the reduced availability of oxygen for the cells adsorbed with pigment at the surface of Escherichia coli cells.
Abstract: Amino acid derivatives of monascus pigments were produced by fermentation, and their antimicrobial activities were determined. Thirty-nine l- and d-forms of amino acids were added as a precursor to the fermentation medium for derivation of pigments. Derivatives with L-Phe, D-Phe, L-Tyr, and D-Tyr exhibited high activities against Gram(+) and Gram(-) bacteria with MIC values of c. 4-8 microg mL(-1). The control red pigment exhibited minimal inhibitory concentration (MIC) values higher than 32 microg mL(-1). Derivatives with L-Asp, D-Asp, L-Tyr, and D-Tyr were effective against the filamentous fungi Aspergillus niger, Penicillium citrinum, and Candida albicans. Monascus derivatives of amino acids having a phenyl ring like Phe and Tyr derivatives showed high antimicrobial activities. Incubation of the l-Phe derivative with Bacillus subtilis caused cells to aggregate with formation of pellets. Easy adsorption of the L-Phe pigment derivative to the surface of Escherichia coli cells was observed via SEM and TEM. Addition of monascus pigment derivatives decreased the oxygen uptake rate of E. coli in culture. The antimicrobial activities of pigment derivatives are considered to be related to the reduced availability of oxygen for the cells adsorbed with pigment.
TL;DR: It is feasible to improve the function of PhyA phytase under stomach pH conditions by rational protein engineering and the improved efficacy of the enzyme was confirmed in an animal feed trial and was characterized by biochemical analysis of the purified mutant enzymes.
Abstract: Environmental pollution by phosphorus from animal waste is a major problem in agriculture because simple-stomached animals, such as swine, poultry, and fish, cannot digest phosphorus (as phytate) present in plant feeds. To alleviate this problem, a phytase from Aspergillus niger PhyA is widely used as a feed additive to hydrolyze phytate-phosphorus. However, it has the lowest relative activity at the pH of the stomach (3.5), where the hydrolysis occurs. Our objective was to shift the pH optima of PhyA to match the stomach condition by substituting amino acids in the substrate-binding site with different charges and polarities. Based on the crystal structure of PhyA, we prepared 21 single or multiple mutants at Q50, K91, K94, E228, D262, K300, and K301 and expressed them in Pichia pastoris yeast. The wild-type (WT) PhyA showed the unique bihump, two-pH-optima profile, whereas 17 mutants lost one pH optimum or shifted the pH optimum from pH 5.5 to the more acidic side. The mutant E228K exhibited the best overall changes, with a shift of pH optimum to 3.8 and 266% greater (P < 0.05) hydrolysis of soy phytate at pH 3.5 than the WT enzyme. The improved efficacy of the enzyme was confirmed in an animal feed trial and was characterized by biochemical analysis of the purified mutant enzymes. In conclusion, it is feasible to improve the function of PhyA phytase under stomach pH conditions by rational protein engineering.
TL;DR: Fungal culturing of PKC brought about an increase in the level of unsaturated- and a decrease in thelevel of the saturated-fatty acids, which affected amino acid, fatty acid, cellulose and hemicellulose fractions.
TL;DR: F3 and F4 strains of Aspergillus niger were screened from five strains of fungi to produce multienzyme preparations (containing cellulase, hemicellulase, glucoamylase, pectinase, and acidic proteinase) as dietary supplementation to optimize media.
Abstract: F3 and F4 strains of Aspergillus niger were screened from five strains of fungi to produce multienzyme preparations (containing cellulase, hemicellulase, glucoamylase, pectinase, and acidic proteinase) as dietary supplementation. Enzyme activities indicated that 1:4 (F3 to F4) was the optimum mixture proportion, and 0.3% (W/W) was the preferable pitching rate. In bran mash containing 54.5% (W/W) water, F3 and F4 could produce the supplementation better when cultured 30 to 36 h at 30 °C. Monofactorial and orthogonal experiments were performed to optimize media. Results of the variance and range analysis showed that the optimum medium contained 80 g of bran, 20 g of cottonseed powder, 1 g of (NH4)2SO4, and 0.1 g of KH2PO4. When F3 and F4 strains were cultured in the optimum medium containing 54.5% (W/W) water, the activity of cellulase, hemicellulase, glucoamylase, pectinase, and acidic proteinase reached 996; 15,863; 13,378; 7,621; and 5,583 U/g, respectively.
TL;DR: Toxin was produced in young colonies after and, typically, did not continue to accumulate the entire surface area of the plate was colonised, rather, the amount decreased as colonies aged.
TL;DR: The enzyme responsible for the esterification was purified and characterized, and was found to be quite similar to an A. niger ferulic acid esterase (FAE-III) in terms of molecular mass, pH and temperature optima, substrate specificity on synthetic substrates, and the N-terminal amino acid sequence.
TL;DR: Three fungal strains of Aspergillus niger, Trichoderma viride and Penicillium spp.
TL;DR: Cellulases are a group of hydrolytic enzymes capable of degrading cellulose to the smaller glucose units that are produced by fungi and bacteria and were observed in R. stolonifer mediated fermentation in solid state fermentation of solid waste of sago industry using cassava tubers.
Abstract: Cellulases are a group of hydrolytic enzymes capable of degrading cellulose to the smaller glucose units. These enzymes are produced by fungi and bacteria. The solid waste of sago industry using cassava tubers was fermented by Aspergillus niger , Aspergillus terreus and Rhizopus stolonifer in solid state fermentation. The cassava waste contained dry wt of 13.4% cellulose and 2.9% protein by dry weight. The highest cellulase activity was observed on the 10 th day in R. stolonifer mediated fermentation. R. stolonifer was more efficient in bioconverting cassava waste into fungal protein (9%) compared to A. niger and A. terreus .