Showing papers on "Aspergillus niger published in 1992"
Journal Article•
TL;DR: The results show that Asp f I is selectively expressed in Aspergillus fumigatus, and suggest that this cytotoxin could be a specific virulence factor for A. fumigsatus, a member of the mitogillin family of cytotoxins.
Abstract: Asp f I is a major 18-kDa Aspergillus fumigatus allergen and a member of the mitogillin family of cytotoxins. The nucleotide sequence of the Asp f I gene was determined by sequencing polymerase chain reaction products amplified from A. fumigatus spore DNA. The entire 678-bp DNA includes an 81-bp leader sequence, preceding the N-terminal alanine codon, a 52-bp intron, and a 444-bp open reading frame, encoding a 149-amino acid protein (M(r) 16,899), which is 99% homologous to mitogillin from Aspergillus restrictus. A mAb-based ELISA was used to compare Asp f I levels in spores, mycelia, and culture filtrate, and to determine the kinetics of allergen production. Disrupted hyphae or spore extracts had a 1000-fold lower level of Asp f I than culture filtrate, suggesting that germination of spores and growth of the fungus are essential for allergen production. Asp f I levels in A. fumigatus and A. restrictus peaked at day 3 (0.87 to 12.1 micrograms/ml), however, the allergen was not detected in Aspergillus flavus, Aspergillus niger, Aspergillus terreus, and Aspergillus nidulans cultures (< 1.5 ng/ml) on either days 3 or 8. Northern analysis confirmed that Asp f I mRNA was detected only in A. fumigatus and A. restrictus, but not in the other four Aspergillus spp. Asp f I-specific DNA was generated after polymerase chain reaction amplification of genomic mycelial DNA obtained from A. fumigatus and A. restrictus, but not from the other Aspergillus spp. The results show that Asp f I is selectively expressed in A. fumigatus, and suggest that this cytotoxin could be a specific virulence factor for A. fumigatus.
162 citations
TL;DR: A novel polygalacturonase (PGC) was produced at high levels by A. niger transformants and a sequence of ten conserved nucleotides comprising a CCAAT sequence was found, likely to represent a binding site for a regulatory protein as it shows a high similarity to the yeast CYC1 upstream activation site recognized by the HAP2/3/4 activation complex.
Abstract: Aspergillusniger produces several polygalacturonases that, with other enzymes, are involved in the degradation of pectin. One of the two previously characterized genes coding for the abundant polygalacturonases I and II (PGI and PGII) found in a commercial pectinase preparation was used as a probe to isolate five more genes by screening a genomic DNA library in phage λEMBL4 using conditions of moderate stringency. The products of these genes were detected in the culture medium of Aspergillus nidulans transformants on the basis of activity measurements and Western-blot analysis using a polyclonal antibody raised against PGI. These transformants were, with one exception, constructed using phage DNA. A. nidulans transformants secreted high amounts of PGI and PGII in comparison to the previously characterized A. niger transformants and a novel polygalacturonase (PGC) was produced at high levels by A. nidulans transformed with the subcloned pgaC gene. This gene was sequenced and the protein-coding region was found to be interrupted by three introns; the different intron/exon organization of the three sequenced A. niger polygalacturonase genes can be explained by the gain or loss of two single introns. The pgaC gene encodes a putative 383-amino-acid prepro-protein that is cleaved after a pair of basic amino acids and shows approximately 60% amino acid sequence similarity to the other polygalacturonases in the mature protein. The N-terminal amino acid sequences of the A. niger polygalacturonases display characteristic amino acid insertions or deletions that are also observed in polygalacturonases of phytopathogenic fungi. In the upstream regions of the A. niger polygalacturonase genes, a sequence of ten conserved nucleotides comprising a CCAAT sequence was found, which is likely to represent a binding site for a regulatory protein as it shows a high similarity to the yeast CYC1 upstream activation site recognized by the HAP2/3/4 activation complex.
128 citations
TL;DR: Beta-glucosidase was purified from a crude cellulase preparation from Aspergillus niger by affinity chromatography on a methacrylamide-N-methylene-bis-methacryamide copolymer bearing cellobiamine to yield 4-O-beta-gentiobiosylglucose in the presence of organic solvents or under neutral conditions.
Abstract: Beta-glucosidase was purified from a crude cellulase preparation from Aspergillus niger by affinity chromatography on a methacrylamide-N-methylene-bis-methacrylamide copolymer bearing cellobiamine. The purified enzyme was a dimer with an isoelectric point of 4.0. The molecular mass of the enzyme was estimated to be 240 kDa by gel-permeation chromatography. The enzyme hydrolyzed specifically beta-glucosidic bonds and catalyzed transglucosylation of the beta-glucosyl group of cellobiose to yield 4-O-beta-gentiobiosylglucose in the presence of organic solvents or under neutral conditions.
110 citations
TL;DR: Evidence was obtained showing that the PLA2 gene was transcribed and that PLA2 is extremely susceptible to both intracellular and extracellular proteases of A. niger, thus indicating that translation products would be rapidly degraded.
103 citations
TL;DR: Comparison of both protoplast and mycelial extracts indicated that, of two constitutive catalases, one is located outside the cell membrane whereas the other is intracellular, indicating that gluconate formation in A. niger occurs extracellularly.
Abstract: The subcellular localization of glucose oxidase (EC 1.1.3.4) in Aspergillus niger N400 (CBS 120.49) was investigated by (immuno)cytochemical methods. By these methods, the bulk of the enzyme was found to be localized in the cell wall. In addition, four different catalases (EC 1.11.1.6) were demonstrated by nondenaturing polyacrylamide gel electrophoresis of crude extracts of induced and noninduced cells. Comparison of both protoplast and mycelial extracts indicated that, of two constitutive catalases, one is located outside the cell membrane whereas the other is intracellular. Parallel with the induction of glucose oxidase, two other catalases are also induced, one located intracellularly and one located extracellularly. Furthermore, lactonase (EC 3.1.1.17) activity, catalyzing the hydrolysis of glucono-delta-lactone to gluconic acid, was found to be exclusively located outside the cell membrane, indicating that gluconate formation in A. niger occurs extracellularly.
102 citations
TL;DR: Proteolytic degradation of heterologous proteins expressed in the filamentous fungus Aspergillus niger reduces the yield of authentic target protein.
Abstract: Proteolytic degradation of heterologous proteins expressed in the filamentous fungusAspergillus niger reduces the yield of authentic target protein. The activities ofA. niger proteases are differentiated by their effects on two proteins expressed and secreted fromA. niger: hen egg-white lysozyme and porcine pancreatic phospholipase A2.
90 citations
TL;DR: The nucleotide sequence of pelB, a member of the Aspergillus niger pectin lyase multigene family, has been determined and two strategies to produce PLB in high amounts under conditions where few other extracellular enzymes are present are tried.
Abstract: The nucleotide sequence of pelB, a member of the Aspergillus niger pectin lyase multigene family, has been determined. The pelB gene product, PLB, shares 65% amino acid identity with pectin lyase A (PLA) and 60% with pectin lyase D (PLD). Although growth of pelB multicopy transformants on pectin-containing media results in elevated pelB mRNA levels, pectin lyase B (PLB) is barely detectable. This is probably due to degradation of PLB by acid proteases, since multicopy transformants grown on pectin medium with a high concentration of phosphate, leading to a less rapid decline in pH, secrete detectable amounts of PLB. To produce PLB in high amounts under conditions where few other extracellular enzymes are present, we tried two strategies. Firstly, heterologous expression of the pelB gene in A. nidulans, and secondly, expression of the pelB gene under control of the constitutive A. niger pki promoter.
79 citations
TL;DR: A lactose-utilizing Saccharomyces cerevisiae that expresses the cDNA for a secreted, thermostable β-galactosidase (lacA) from Aspergillus niger may offer a solution to the increasing problem of waste whey disposal.
Abstract: We describe the construction of a lactose-utilizing Saccharomyces cerevisiae that expresses the cDNA for a secreted, thermostable beta-galactosidase (lacA) from Aspergillus niger. Yeast cells expressing the lacA gene from the yeast ADH1 promotor on a multicopy plasmid secrete up to 40% of the total beta-galactosidase activity into the growth medium. The secreted product is extensively N-glycosylated, and cells expressing the lacA gene grow on whey permeate (4% w/v lactose) with a doubling time of 1.6 hours. Such strains may offer a solution to the increasing problem of waste whey disposal.
71 citations
TL;DR: The cloned gene (aglA) was shown to be functional by demonstrating that the 82 kDa α-galactosidase is absent from a strain with a disruption of the agIA gene, and is over-produced in strains containing multiple copies of the AglA gene.
Abstract: An enzyme with α-galactosidase activity and an apparent molecular weight of 82 kDa was purified from culture medium of Aspergillus niger. The N-terminal amino acid sequence of the purified protein shows similarity to the N-terminal amino acid sequence of α-galactosidases from several other organisms. Oligonucleotides, based on the N-terminal amino acid sequence, were used as probes to clone the corresponding gene from a λ EMBL3 gene library of A. niger. The cloned gene (aglA) was shown to be functional by demonstrating that the 82 kDa α-galactosidase is absent from a strain with a disruption of the agIA gene, and is over-produced in strains containing multiple copies of the aglA gene. Enzyme activity assays revealed that the 82 kDa α-galactosidase A represents a minor extracellular α-galactosidase activity in A. niger.
69 citations
TL;DR: Fungal NR shows considerable aa homology with higher plant NR, particularly within the co-factor domains for flavin adenoside dinucleotide, heme and molybdopterin cofactor.
57 citations
TL;DR: Although the species Aspergillus niger is infrequently encountered, the endobronchial visualization of black necrotic debris or a fungus ball or the finding of black acidic sputum or pleural fluid suggests the presence of A niger and the destructive by-product of its fermentation, oxalic acid.
TL;DR: The biotic elicitors were effective, although the extent to which elicitation occurred differed from elicitor to elicitor, and the highest production increase was attained with the extract of Aspergillus niger, an increase of 85% compared to the control.
TL;DR: It is concluded that cassava peel might be a better substrate for the production of amylase by Aspergillus flavus and A. niger than commercial soluble starch.
Abstract: Aspergillus flavus andAspergillus niger produce extracellular amylase into the culture medium when grown on basal medium containing 2% (w/v) soluble starch or cassava peel as the sole carbon source. On soluble tarch the highest amylase activities were 1.6 and 5.2 mg of starch hydrolyzed/min per mg protein forA. flavus andA. niger, respectively. When grown on cassava peel, the highest amylase activity in the culture filtrate ofA. flavus was 170-times higher than that on soluble starch, while that ofA. niger was 16-times higher. The mycelial dry weight for both organisms was not significantly affected by the carbon sources. Maximum enzyme activity was obtained at the growth temperature of 29.0±1°C and pH 7 for both organisms. It is concluded that cassava peel might be a better substrate for the production of amylase byA. flavus andA. niger than commercial soluble starch.
TL;DR: Many mutant strains showing resistance to 2-deoxy-d-glucose (DG) on minimal medium containing glycerol as a carbon source were induced from Aspergillus niger WU-2223L, a citric acid-producing strain, and were classifiable into two types according to their growth characteristics.
Abstract: Many mutant strains showing resistance to 2-deoxy-d-glucose (DG) on minimal medium containing glycerol as a carbon source were induced from Aspergillus niger WU-2223L, a citric acid-producing strain. The mutant strains were classifiable into two types according to their growth characteristics. On the agar plates containing glucose as a sole carbon source, mutant strains of the first type showed good growth irrespective of the presence or absence of DG. When cultivated in shake cultures, some strains of the first type, such as DGR1–2, showed faster glucose consumption and growth than strain WU-2223L. The period for citric acid production shortened from 9 days for strain WU-2223L to 6–7 days for these mutant strains. The levels and yields of citric acid production of the mutant strains were almost the same as those of strain WU-2223L. The mutant strains of the second type, however, showed very slow or no growth on both the agar plates containing glucose and fructose as sole carbon sources. In shake cultures, mutant strains such as DGR2-8 showed decreased glucose consumption rates, resulting in very low production of citric acid.
TL;DR: The complete Amino Acid Sequence of Crystalline (α-glucosidase) from Aspergillus niger was published in 1992 as mentioned in this paper, with a focus on protein synthesis.
Abstract: (1992). Complete Amino Acid Sequence of Crystalline (α–Glucosidase from Aspergillus niger. Bioscience, Biotechnology, and Biochemistry: Vol. 56, No. 8, pp. 1368-1370.
TL;DR: Two extracellular β-glucosidases were isolated from Aspergillus nigerUSDB 0827 and A. niger USDB 0828 and were very similar in terms of molecular size, pH optimum, temperature optimum, stability at high temperatures and substrate preferences, but differed in inhibition by glucono-1,5-lactone and affinity for cellobiose.
Abstract: Two extracellular β-glucosidases (EC 3.2.1.21) were isolated from Aspergillus niger USDB 0827 and A. niger USDB 0828, and their physical and kinetic properties studied. Both enzymes were very similar in terms of molecular size (230000 Da), pH optimum (pH 4.6), temperature optimum (65° C), stability at high temperatures and substrate preferences. They were capable of hydrolysing β-linked disaccharides, phenyl β-d-glucoside, p-nitrophenyl β-d-glucoside (PNPG), o-nitrophenyl β-d-glucoside, salicin and methyl β-d-glucoside but lacked activity towards α-linked disaccharides, a range of p-nitrophenyl monoglycosides and p-nitrophenyl diglycosides. Both β-glucosidases were better at hydrolysing cellobiose than cellotriose, cellotetraose or cellopentaose. For both enzymes, glucose showed competitive inhibition with PNPG as substrate but had no effect with cellobiose. However, the two β-glucosidases differed in inhibition by glucono-1,5-lactone and affinity for cellobiose. β-Glucosidase from A. niger USDB 0827 also gave lower specific activity, and was more susceptible to metal ions (Ag+, Fe2+ and Fe3+) inhibition than that of A. niger USDB 0828.
TL;DR: Two kinds of α-glucuronidases, CM-I and CM-II, were purified from a cell-free extract of Aspergillus niger 5–16 and were strongly inhibited by Ag+, Hg2+, Pb2+, Sn2, Fe2+, Fe3+, Al3+, sodium dodecyl sulfate, monoiodoacetic acid, and N-bromosuccinimide.
Abstract: Two kinds of α-glucuronidases, CM-I and CM-II, were purified from a cell-free extract of Aspergillus niger 5–16. Molecular weights of both CM-I and CM-II were 130,000 by SOS–PAGE, and 150,000 by gel filtration. The optimum temperature and pH for both enzyme reactions were 60°C and 4.8. Both en-zymes were stable up to 50°C, and between pHs 4.5 to 7.0 for 1 hr. Both enzymes were strongly inhibited by Ag+, Hg2+, Pb2+, Sn2+, Fe2+, Fe3+, Al3+, sodium dodecyl sulfate, monoiodoacetic acid, and N-bromosuccinimide.The Km of CM-I toward glucuronosyl-xylotriose and 4-O-methyl-glucuronosyl-xylotriose were 0.77 and 0.37, and those of CM-II were 0.82 and 0.47 mM, respectively. The Vmax of CM-I toward glucuronosyl-xylotriose and 4-0-methyl-glucuronosyl-xylotriose were 5.20 and 1.42, and those of CM-II were 17.1 and 4.68μmol of glucuronic acid formed/min/mg of protein, respectively.
TL;DR: Analysis of Aspergillus niger pyrA co-transformants with multiple copies of the gene (pgaII) encoding the major endopolygalacturonase indicated that the most frequent event involved is the excision of part of the array of tandemly integrated plasmids, without “scrambling” of the plasmid remaining in the chromosome.
Abstract: Aspergillus niger pyrA co-transformants with multiple copies of the gene (pgaII) encoding the major endopolygalacturonase were characterized in detail. Typically, these transformants produced tenfold or more polygalacturonase from plasmids that had integrated in most cases at ectopic sites, in comparison to the untransformed strain. Some mitotic instability was observed upon application of a positive selection procedure for reversion of the pyrA marker. Analysis of these strains indicated that the most frequent event involved is the excision of part of the array of tandemly integrated plasmids, without “scrambling” of the plasmids remaining in the chromosome. From promoter deletion analysis it was concluded that the pgaII gene is subject to positive control. The putative positive regulatory protein appears not to be limiting for overexpression of the pgaII gene.
Patent•
23 Mar 1992TL;DR: In this paper, a process for expression of a protein product in Aspergillus niger is described, which enables industrial production of many different polypeptides and proteins.
Abstract: A process for expression of a protein product in Aspergillus is disclosed. The process comprises transforming an Aspergillus strain with a vector system comprising DNA-sequences encoding a promoter including upstream activating sequences derived from an A. niger amylase, a suitable marker for selection of transformants, and a DNA-sequence encoding the desired protein product. The process enables industrial production of many different polypeptides and proteins in Aspergillus, preferably A. niger. Examples of such products are chymosin or prochymosin and other rennets, proteases, lipases and amylases. Also disclosed is an effective promoter for expression of a protein in Aspergillus, preferably Aspergillus niger being derived from a gene encoding an A. niger amylase. The A. niger amylases are the neutral and acid stable α-amylases and a new amylase not so far described and designated XA amylase. Also disclosed is the novel amylase from A. niger XA amylase.
TL;DR: The production of the enzyme appeared to be inducible as it was only produced when apiin, an apiosylglucoside, was present in the culture medium and the influence of apiin concentration, nitrogen source, and surfactants on enzyme production was studied.
Abstract: Various aspects of fungus-originated β-apiosidase were studied. The production of the enzyme on various carbon sources by fungi appeared to be inducible as it was only produced when apiin, an apiosylglucoside, was present in the culture medium. The influence of apiin concentration, nitrogen source, and surfactants on enzyme production was studied. The enzyme was partially purified by filtration chromatography on Ultrogel AcA44 and ion-exchange chromatography on DEAE-Sepharose CL6B
TL;DR: A ferrocene-derivatised detergent, (11-ferrocenylundecyl) trimethylammonium bromide (FTMAB), when oxidised to the corresponding ferricinium ion, was found by electrochemical studies to be an effective electron acceptor for reduced glucose oxidation of Aspergillus niger and thus acts as a electron-transfer mediator between glucose oxidase and a working electrode held at a potential sufficiently positive to reox
TL;DR: Several 2-chloro and 2-bromo-3-(substituted)-1,4-naphthoquinone derivatives demonstrated a broad spectrum of activities in vitro against Bacillus subtilis and Pseudomonas aeruginosa, Candida albicans, Aspergillus niger.
Abstract: In order to evaluate the antimicrobial effect of 2,3-disubstituted-1,4-naphthoquinone derivatives we newly synthesized several 2-chloro and 2-bromo-3-(substituted)-1,4-naphthoquninones. Amination reaction of 2,3-dihalo-1,4-naphthoquinones with aryl and aliphatic amines in ethanol gave 2-halo-3-(N-alkyl or N-aryl)-1,4-naphthoquinone derivatives (1a,b–10a,b) in 60%–90% yield. These derivatives subjected to antibacterial and antifungal activities,in vitro, againstBacillus subtilis ATCC 6633, Candida albicans 10231 and local, Pseudomonas aeruginosa NCTC10490, Staphylococcus aureus ATCC 6538p, Escherichia coli NIHJ, Aspergillus niger KCTC 1231. Tricophyton mentagrophytes KCTC 6085. Among these derivatives,1b, 6b and7a showed the potent antibacterial activities.1b, 8b and9b have the antifungal activities.1b is most effective in preventing the growth ofBacillus subtilis and Pseudomonas aeruginosa, Candida albicans, Aspergillus niger. Tricophyton mentagrophytes. The several of these compounds demonstrated a broad spectrum of activitiesin vitro.
TL;DR: A process of continuous citric acid production from sugarcane molasses by fermentation with immobilized whole cells of A. niger KCU 520 is described and both calcium alginate beads and polyacrylamide gel (PAG) slab entrapment methods were used for immobilization of cells.
Abstract: A process of continuous citric acid production from sugarcane molasses by fermentation with immobilized whole cells of A. niger KCU 520 is described. Both calcium alginate beads and polyacrylamide gel (PAG) slab entrapment methods were used for immobilization of cells. The optimum fermentation conditions for citric acid fermentation by immobilized cells were sugars, 10%; pH, 4.0; inoculum size, 20%, and temperature, 32-35°C. With calcium-alginate and PAG-immobilized cells, an overall citric acid production rate of 8.5g and 12.0g/l/day (9.3% and 12% sugar conversion to citric acid per day), respectively was achieved in a single-stage bioreactor. When the PAG-immobilized cells were used in a two-stage bioreactor, approximately 20.0g citric acid/l/day (20% sugar conversion to citric acid per day) was produced and the PAG-immobilized cells were continuously used for at least 20 days without any significant loss of productivity.
TL;DR: Aspergillus niger was used for the hydrolysis of sugar cane bagasse and the resulting hydrolyzate was used as a substrate for single cell protein (SCP) production using Candida utilis, and highest protein content was observed at an early stage of growth.
Abstract: Aspergillus niger was used for the hydrolysis of sugar cane bagasse and the resulting hydrolyzate was used as a substrate for single cell protein (SCP) production using Candida utilis . Up to 7.8% of fermentable sugar was produced after growing A. niger on optimized bagasse medium for 4 days. Delignification of bagasse greatly improved the saccharification process. Supplementation of the growth medium with 4 g l −1 yeast extract and 4 g l −1 (NH 4 ) 2 S0 4 , improved the yield of biomass, carbohydrate consumption and protein content of Candida utilis . Highest protein content was observed at an early stage of growth (24 h). The kinetic model for SCP production used and the kinetic parameters were calculated. The specific growth rate of Candida utilis was also calculated.
TL;DR: From mild acid hydrolysis, methylation analysis and ROESY spectral analysis, it was ascertained that the galactosyl residue in two oligosaccharides was in the furanose form and was bound to mannose at the nonreducing end with an α1–2 linkage.
Abstract: Structures of oligosaccharides fromAspergillus niger α-d-galactosidase [EC 3.2.1.22] were studied. Purified α-d-galactosidase was treated withN-glycosidase F, and six kinds of oligosaccharides were isolated by gel chromatography and anion-exchange chromatography. The structures of the oligosaccharides were determined by1H-NMR and compositional analysis to be Man5GlcNAc2, Man6GlcNAc2, Man9GlcNAc2, GlcMan9GlcNAc2, GalMan4GlcNAc2 and GalMan5GlcNAc2. From mild acid hydrolysis, methylation analysis and ROESY spectral analysis, it was ascertained that the galactosyl residue in two oligosaccharides was in the furanose form and was bound to mannose at the nonreducing end with an α1–2 linkage (GalfMan4GlcNAc2 and GalfMan5GlcNAc2).
TL;DR: In A. niger, regulation of PFK 2 by phosphorylation/dephosphorylation does not occur, and this is related to the development of high glycolytic flow and citrate accumulation under conditions of supplying high sugar concentrations.
Abstract: Phosphofructokinase 2 (PFK 2) was isolated from mycelia of the citric-acid-accumulating fungus Aspergillus niger, and partially purified by Trisacryl-Blue chromatography and Mono Q fast protein liquid chromatography. The appearance of a 96/94-kDa double band correlated with PFK 2 activity during purification. Purified PFK 2 had a half-life of 240 min at 4° C. The enzyme exhibited Michaelis-Menten type kinetics with respect to its substrates fructose-6-phosphate and ATP, required inorgaic phosphate for activity, and was only weakly inhibited by phospho(enol)pyruvate, AMP and citrate. The enzyme activity was not influenced by incubating partially purified PFK 2 preparations with ATP, MG2+ and the catalytic subunit of bovine heart protein kinase, although such treatment phosphorylated the 96/94-kDa protein. Consistently, treatment with alkaline phosphatase had no effect on PFK 2 activity. Also, no influence on PFK 2 activity was observed when cell-free extracts (containing A. niger protein kinases) from either glucose or citrate-grown mycelia were incubated with ATP and Mg2+ alone. It is concluded that, in A. niger, regulation of PFK 2 by phosphorylation/dephosphorylation does not occur, and this is related to the development of high glycolytic flow and citrate accumulation under conditions of supplying high sugar concentrations.
TL;DR: The production of gluconic acid was carried out with high catalase containing Aspergillus niger mutant, which enables to convert the concentrated solutions of D-glucose to D-gluconic acids without gasing using hydrogen peroxide as oxygen source.
Abstract: The production of gluconic acid was carried out with high catalase containing Aspergillus niger mutant. This osmofil strain enables to convert the concentrated solutions of D-glucose (300g/l) to D-gluconic acid without gasing using hydrogen peroxide as oxygen source. A controlled addition of hydrogen peroxide based on the pO2 measurement was performed. The conversion of 300g/l glucose solution was achieved with 7 hours and triple conversion (with biomass recycling) within 27 hours with yield with regard to the substrate over 98%. Kinetics of inactivation of glucose oxidasecatalase complex as a whole was examined. Some general factors influencing the inactivation of glucose oxidase and catalase in mycelium are discussed.
TL;DR: Tests performed on nine commercial native collagens have showed the enzyme being able to hydrolyze the collagen chain without amino acid being released and to liberate low molecular weight peptides of potential interest in therapeutics.
Patent•
09 Dec 1992
TL;DR: In this article, the authors described methods for the isolation and characterization of DNA sequences from Aspergillus niger var. awamori which are involved in the expression and secretion of endoxylanase II (exlA) by said Asgergillus mould.
Abstract: Methods are described for the isolation and characterization of DNA sequences from Aspergillus niger var. awamori which are involved in the expression and secretion of endoxylanase II (exlA) by said Aspergillus mould. A process using these expression and/or secretion regulating regions to direct the production and optionally the secretion of proteins other than endoxylanase II by transformed moulds is provided.
TL;DR: This paper investigated the necessary treatments of beet molasses to improve its suitability as a substrate for citric acid (CA) production by a potent strain of Aspergillus niger van Tieghem.