| identification of residues involved in active-site formation in aspergillus ficuum phytase. | | 1992 | 1335713 |
| molecular and kinetic properties of aspergillus ficuum inulinases. | the beta-fructosidases from the thermotolerant fungus, a. ficuum, were characterized. all were active as to inulin and sucrose hydrolysis with different specificity constants (kcat/km). the enzymes were classified according to the ratio (alpha) of the specificity constants for inulin (i) and sucrose (s). the invertase showed an alpha value of lower than one, while the inulinases had alpha values of higher than one. the alpha ratio is proposed for the classification of beta-fructosidases into the ... | 1990 | 1368526 |
| cyclohexanedione modification of arginine at the active site of aspergillus ficuum phytase. | reaction of aspergillus ficuum phytase with the arginine specific modifier 1,2-cyclohexanedione causes a rapid loss of activity. the inactivation can be partially reversed by 0.2 m hydroxylamine and exhibits pseudo-first order kinetics. the reaction order and second order rate constant of inactivation were 0.87 and 6.72 m-1 min-1, respectively. amino acid analysis of modified phytase indicates that about 7 arginine of the total 19 were modified. while the chymotryptic maps of treated and untreat ... | 1991 | 1648914 |
| aspergillus ficuum extracellular phytase. peptide mapping and purification by reverse phase chromatography. | | 1990 | 1963766 |
| extracellular alpha galactosidase (e.c. 3.2.1.22) from aspergillus ficuum nrrl 3135 purification and characterization. | extracellular alpha-galactosidase, a glycoprotein from the extracellular culture fluid of aspergillus ficuum grown on glucose and raffinose in a batch culture system, was purified to homogeneity in five steps by ion exchange and hydrophobic interaction chromatography. the molecular mass of the enzyme was 70.8 kd by sds polyacrylamide gel electrophoresis and 74.1 kd by gel permeation hplc. on the basis of a molecular mass of 70.7 kd, the molar extinction coefficient of the enzyme at 279 nm was es ... | 1990 | 2287609 |
| production, rapid purification and catalytic characterization of extracellular phytase from aspergillus ficuum. | a rapid purification scheme utilizing three chromatographic steps resulted in 6 fold purification of aspergillus ficuum phytase (myo-inositol-hexakisphosphate 3-phosphohydrolase, ec 3.1.3.8). at ph 5.0 and 60 degrees c the enzyme performed acceptably for 2.0 hr with only 30% diminished catalytic rate at the end. substrate concentration exceeding 2mm was inhibitory. the inorganic orthophosphate, the product and a weak inhibitor, exhibited a ki of 1.9 x 10(-3)m. the extracellular phytase has the p ... | 1988 | 2852806 |
| aspergillus ficuum phytase: partial primary structure, substrate selectivity, and kinetic characterization. | purified aspergillus ficuum phytase's partial primary structure and amino acid and sugar composition were elucidated. determination of kinetic parameters of the enzyme at different ph values and temperatures indicated no significant alteration of the km for phytate while the kcat was affected. the enzyme was able to release more than 51% of the total available pi from phytate in a 3.0 hr assay at 58 degrees c, but the kcat dropped to 15% of the initial rate. substrate selectivity studies reveale ... | 1988 | 2852807 |
| immobilization of aspergillus ficuum phytase: product characterization of the bioreactor. | aspergillus ficuum phytase was covalently immobilized on fractogel tsk hw-75 containing 2-oxy-l-alkylpyridinium salts. a packed-bed bioreactor was constructed with the immobilized phytase. an hplc ion-exchange method was used to analyze the enzymatic products of the bioreactor. immobilized fungal phytase was able to hydrolyze myo-inositol hexa-, penta-, tetra-, tri-, and diphosphates. when the substrate solution was recirculated for 5 hr in the bioreactor about 50% inorganic orthophosphate was r ... | 1988 | 2852808 |
| extracellular phytase (e.c. 3.1.3.8) from aspergillus ficuum nrrl 3135: purification and characterization. | extracellular phytase from aspergillus ficuum, a glycoprotein, was purified to homogeneity in 3 column chromatographic steps using ion exchange and chromatofocusing. results of gel filtration chromatography and sds-polyacrylamide gel electrophoresis indicated the approximate molecular weight of the native protein to be 85-100-kda. on the basis of a molecular weight of 85-kda, the molar extinction coefficient of the enzyme at 280 nm was estimated to be 1.2 x 10(4) m-1 cm-1. the isoelectric point ... | 1987 | 3035533 |
| extracellular ph 2.5 optimum acid phosphatase from aspergillus ficuum: immobilization on modified fractogel. | aspergillus ficuum ph 2.5 optimum acid phosphatase (orthophosphoric monoesters phosphohydrolase, e.c.3.1.3.2) was covalently immobolized on 2-fluoro-1-methylpyridinium toluene-4-sulfonate (fmp)-activated fractogel tsk hw-50f. the catalytic parameters and stability of the immobilized enzyme were compared with those of the free enzyme. while the km and the temperature optima were unchanged, the ki for orthophosphate was changed from 185 microm to 422 microm and greater stability was observed again ... | 1988 | 3231600 |
| aspergillus ficuum extracellular ph 6.0 optimum acid phosphatase: purification, n-terminal amino acid sequence, and biochemical characterization. | an extracellular acid phosphatase, ph optimum 6.0 from crude culture filtrate of aspergillus ficuum was purified to homogeneity using cation exchange chromatography and chromatofocusing steps. sds-page of the purified enzyme exhibited two stained bands at approximately 82-kda and 70-kda. the mobility of the active enzyme in gel permeation chromatography indicated the molecular mass to be about 85-kda. in the concentrated form the enzyme appeared to be purple, the visible absorption spectrum show ... | 1988 | 3375203 |
| purification, n-terminal amino acid sequence and characterization of ph 2.5 optimum acid phosphatase (e.c. 3.1.3.2) from aspergillus ficuum. | an acid phosphatase from crude culture filtrate of aspergillus ficuum was purified to homogeneity using three ion exchange chromatographic steps. sds-page of the purified enzyme gave a single stained band at approximately 68-kda. the mobility of the native enzyme in gel filtration chromatography, however, indicated that the molecular mass to be about 130-kda implying the active form to be a dimer. on the basis of a molecular mass of 68-kda, the molar extinction coefficient of the enzyme at 280 n ... | 1987 | 3438253 |
| regulation of the formation of acid phosphatases by inorganic phosphate in aspergillus ficuum. | two types of extracellular acid phosphatases are synthesized by aspergillus ficuum nrrl 3135: a nonspecific orthophosphoric monoester phosphohydrolase (ec 3.1.3.2) with an optimum ph of 2.0, and an enzyme with restricted specificity, a mesoinositol-hexaphosphate phosphohydrolase (ec 3.1.3.8; phytase) with an optimum ph of 5.5. although the ph 5.5 enzyme is termed a phytase, both enzymes hydrolyze phytin. synthesis of the enzymes is repressed by high orthophosphate concentrations in the fermentat ... | 1969 | 4311867 |
| inositol phosphate phosphatases of microbiological origin: the inositol pentaphosphate products of aspergillus ficuum phytases. | the fungus aspergillus ficuum nrrl 3135 is known to produce an extracellular nonspecific orthophosphoric monoester phosphohydrolase (ec 3.1.3.2) with a ph optimum of 2.0, as well as an extracellular myo-inositol hexaphosphate phosphohydrolase (ec 3.1.3.8; phytase) with ph optima of 2.0 and 5.5. both these enzymes are also known to hydrolyze myo-inositol hexaphosphate. the pentaphosphates liberated in the first step of this hydrolysis have been isolated and identified by ion-exchange chromatograp ... | 1972 | 4342816 |
| inositol phosphate phosphatases of microbiological origin. some properties of the partially purified phosphatases of aspergillus ficuum nrrl 3135. | | 1974 | 4372982 |
| aspergillus ficuum phytase active site: involvement of arg and trp residues. | | 1995 | 7785880 |
| an acid phosphatase from aspergillus ficuum has homology to penicillium chrysogenum phoa. | three secreted acid phosphatases had previously been characterized from aspergillus ficuum grown under conditions of limited phosphate. one of these could not be readily separated from afphyb, a ph 2.5 optimum acid phosphatase with phytase activity. from extensive protein sequence analysis and subsequent cloning of the gene, we have shown that the afphyb protein fraction contains a fourth secreted acid phosphatase (afphoa) that has 64% homology to a phosphate-repressible acid phosphatase from pe ... | 1994 | 7945393 |
| the complete primary structure elucidation of aspergillus ficuum (niger), ph 6.0, optimum acid phosphatase by edman degradation. | the primary structure of the aspergillus ficuum (niger) nrrl 3135 extracellular, ph 6.0, optimum acid phosphatase (e.c.3.1.3.2) was elucidated by gas phase sequencing. it was deduced by sequence overlap of peptides obtained from trypsin, chymotrypsin, clostripain, and cyanogen bromide digests of the pyridylethylated protein. the mature, active protein is composed of 583 amino acids, including 13 glycosylated asn residues. the unglycosylated protein has a mw of 64,245-kda and a pi of 4.97. two pu ... | 1994 | 8074654 |
| use of polyethylene glycol and high-performance liquid chromatography for preparative separation of aspergillus ficuum acid phosphatases. | proteins of aspergillus ficuum culture filtrate were sequentially fractionated with 4, 9, 15, 19, 24, 30 and 36% polyethylene glycol (peg) into seven acid phosphatases (apases) with 93% and 52% overall recoveries of activity and protein, respectively. crude extract was also separated into seven apase peaks on a 30 cm x 2.5 cm i.d. anion-exchange column using 0.1 m tris-hcl (ph 8.0) and a 0-0.4 m kcl gradient as the eluent, but their resolution was incomplete. however, when individual peg precipi ... | 1994 | 8118550 |
| aspergillus ficuum phytase: complete primary structure elucidation by chemical sequencing. | the primary structure of aspergillus ficuum phytase was deduced from overlaps in peptide sequences. the unglycosylated enzyme is a 441 residue protein with a molecular mass of 48.5-kda, as calculated from the total covalent structure. the estimated pl of the protein is about 4.76. of the 19 asn residues, 9 were found to be glycosylated. the phytase consists of 37% non-polar, 42% polar, 11.5% acidic, and 9.5% basic amino acids. the putative active site of the enzyme containing the sequence rhg is ... | 1993 | 8387289 |
| identification of active-site residues in aspergillus ficuum extracellular ph 2.5 optimum acid phosphatase. | primary structure elucidation of peptides generated by cyanogen bromide, endoproteinase glu-c, and clostripain cleavage of an aspergillus ficuum extracellular ph optimum 2.5 acid phosphatase identified a region which contains the active site of the enzyme. the 23-residue segment contains the fragment rhgxrxp, which is homologous to acid phosphatase from saccharomyces spp., aspergillus ficuum, mammals, and bacteria. homologous or conservative substitutions are observed in the 10-amino acid fragme ... | 1993 | 8484781 |
| disulfide bonds are necessary for structure and activity in aspergillus ficuum phytase. | the function of disulfide bonds in aspergillus ficuum phytase was elucidated by unfolding studies, using guanidinium hydrochloride (gu.hcl) as denaturant. although the enzyme is totally inactivated by 0.8 m gu.hcl, at ph 5.0, the active conformation is instantaneously restored by 0.6 m gu.hcl, at ph 5.0. conditions which would permit refolding of phytase are completely negated by 10 mm beta-mercaptoethanol and causes its catalytic demise at ph 7.5. assay of free thiols using ellman's reagent ind ... | 1996 | 8878514 |
| deglycosylation of proteins for crystallization using recombinant fusion protein glycosidases. | obtaining high quality protein crystals remains a rate-limiting step in the determination of three-dimensional x-ray structures. a frequently encountered problem in this respect is the high or heterogeneous carbohydrate content of many eukaryotic proteins. a number of reports have demonstrated the use of enzymatic deglycosylation in the crystallization of certain glycoproteins. although this is an attractive tool, there are some problems that hinder the more widespread use of glycosidases in cry ... | 1996 | 8976570 |
| crystal structure of phytase from aspergillus ficuum at 2.5 a resolution. | phytase is a high molecular weight acid phosphatase. the structure has an alpha/beta-domain similar to that of rat acid phosphatase and an alpha-domain with a new fold. | 1997 | 9164457 |
| differences in the active site environment of aspergillus ficuum phytases. | while aspergillus ficuum phytasea (phya) was rapidly inactivated by 1,2-cyclohexanedione and phenylglyoxal, both specific modifiers of arginine, phytaseb (phyb) showed a markedly different behavior. first, phyb was totally insensitive to 1,2-cyclohexanedione even in the presence of 0.2 m guanidinium hydrochloride; second, the enzyme showed a great deal of resistance to inactivation by phenylglyoxal. taken together, these results indicate that the chemical environment of the active site of phyb i ... | 1998 | 9480830 |
| myo-inositol hexasulfate is a potent inhibitor of aspergillus ficuum phytase. | myo-inositol hexasulfate (mihs), a structural analog of the substrate myo-inositol hexaphosphate, is a potent competitive inhibitor of both phya and phyb enzymes. the ki of inhibition for the phya and phyb proteins were estimated to be 4.6 and 0.2 microm, respectively. thus, the phyb protein is 23-fold more sensitive to mihs inhibition than the phya protein. the active-site geometry of phyb protein is presumed to be very different from the phya protein as deduced by chemical probing of the enzym ... | 1998 | 9790943 |
| purification and characterization of aspergillus ficuum endoinulinase. | endoinulinase from aspergillus ficuum, which catalyzes the hydrolysis of inulin via an endo-cleavage mode, was purified by chromatography from novozym 230 as a starting commercial enzyme mixture on cm-sephadex and deae-sepharose, and by preparative electrophoresis under native conditions. the enzyme was estimated to be pure on the basis of its i/s ratio, whose value was infinite in our assay conditions. two forms separated by using this method. sds gel electrophoresis showed the two purified for ... | 1999 | 10052135 |
| dephosphorylation of phytate by using the aspergillus niger phytase with a high affinity for phytate. | a phytase (ec 3.1.3.8) with a high affinity for phytic acid was found in aspergillus niger sk-57 and purified to homogeneity in four steps by using ion-exchange chromatography (two types), gel filtration, and chromatofocusing. sodium dodecyl sulfate-polyacrylamide gel electrophoresis of the purified enzyme gave a single stained band at a molecular mass of approximately 60 kda. the michaelis constant of the enzyme for phytic acid (18.7 +/- 4.6 microm) was statistically analyzed. in regard to the ... | 1999 | 10508107 |
| characterization of recombinant fungal phytase (phya) expressed in tobacco leaves. | the phya gene from aspergillus ficuum coding for a 441-amino-acid full-length phytase was expressed in nicotiana tabacum (tobacco) leaves. the expressed phytase was purified to homogeneity using ion-exchange column chromatography. the purified phytase was characterized biochemically and its kinetic parameters were determined. when the recombinant phytase was compared with its counterpart from aspergillus ficuum for physical and enzymatic properties, it was found that catalytically the recombinan ... | 1999 | 10527865 |
| the rational design of semisynthetic peroxidases. | a semisynthetic peroxidase was designed by exploiting the structural similarity of the active sites of vanadium dependent haloperoxidases and acid phosphatases. incorporation of vanadate ion into the active site of phytase (e.c. 3.1.3.8), which mediates in vivo the hydrolysis of phosphate esters, leads to the formation of a semisynthetic peroxidase, which catalyzes the enantioselective oxidation of prochiral sulfides with h(2)o(2) affording the s-sulfoxide, e.g. in 66% ee at 100% conversion for ... | 2000 | 10581439 |
| comparative enzymatic hydrolysis of phytate in various animal feedstuff with two different phytases. | bacillus amyloliquefaciens ds11 phytase (ds11 phytase) and aspergillus ficuum phytase (af phytase) activities were investigated by measuring the release of phosphate from phytate in animal feedstuff such as wheat bran, corn meal, soybean meal and rice flour at ph 5 and 7. in all the tested feedstuff, the enzymatic activity of ds11 phytase was more active at ph 7, but that of af phytase was more active at ph 5. from these results, the phytate in the gastrointestinal tract could be degraded in the ... | 1999 | 10593587 |
| highly efficient immobilization of glycosylated enzymes into polyurethane foams. | glycosylated enzymes, including aminoacylase from aspergillus melleus, chloroperoxidase from caldariomyces fumago, and phytase from aspergillus ficuum, were covalently immobilized into polyurethane foams with very high enzyme loadings of up to 0.2 g protein per gram dry foam. the immobilization efficiency (retained activity) ranged from 100% at a low loading to 60% at high loadings. in contrast to many other immobilization methods no leaching of the enzyme from the support took place under the r ... | 2000 | 10992238 |
| characterisation of the high-molecular weight fructan isolated from garlic (allium sativum l.). | a high molecular weight fructan was isolated from garlic and the structure determined by enzymatic, chemical and spectroscopic (nmr) methods. it was found that the garlic fructan belongs to the neokestose family. it has a (2 --> 1)-linked beta-d-fruf backbone with (2 --> 6)-linked beta-d-fruf side chains. a structural model was postulated for a degree of polymerisation of about 58. this model was substantiated using an endo-inulinase purified from aspergillus ficuum and by 1h and 13c nmr spectro ... | 2000 | 11028785 |
| comparison of phytase from genetically engineered aspergillus and canola in weanling pig diets. | ninety-six crossbred pigs with an average weight of 9.0 kg were used in a 5-wk trial to compare the efficacy of genetically engineered aspergillus ficuum phytase, expressed in aspergillus niger (natuphos) or in canola seed (phytaseed), for enhancing the utilization of phytate p in corn-soybean meal-based diets fed to young pigs and to evaluate the safety of phytaseed phytase. three levels of the two sources of phytase (250, 500, or 2,500 u/kg of diet) were added to a corn-soybean meal basal diet ... | 2000 | 11063311 |
| sucrose hydrolysis by thermostable immobilized inulinases from aspergillus ficuum. | the possibility of using thermostable inulinases from aspergillus ficuum in place of invertase for sucrose hydrolysis was explored. the commercial inulinases preparation was immobilized onto porous glass beads by covalent coupling using activation by a silane reagent and glutaraldehyde before adding the enzyme. the immobilization steps were optimized resulting in a support with 5,440 iu/g of support (sucrose hydrolysis) that is 77% of the activity of the free enzyme. enzymatic properties of the ... | 2001 | 11339940 |
| identification, classification and phylogeny of the aspergillus section nigri inferred from mitochondrial cytochrome b gene. | the partial mitochondrial cytochrome b gene from 32 strains of 12 species belonging to aspergillus section nigri was amplified by the polymerase chain reaction and sequenced directly. using 402 nucleotide characters, nucleotide-based and amino acid-based phylogenetic trees were inferred and the genetic divergence among the species was evaluated. based on analyses of the 402-bp nucleotide and 133-amino acid sequences, strains were divided into 11 dna types and five amino acid types. aspergillus n ... | 2001 | 11425482 |
| decolorization of direct black 22 by aspergillus ficuum. | the decolorization of direct black 22 by aspergillus ficuum has been studied. it was found that aspergillus ficuum could effectively decolorize direct black 22 especially when grown as pelleted mycelia. results showed that the media containing direct black 22 at 50 mg/l could be decolorized by 98.05% of the initial color in 24 h. the optimum ph and temperature of decolorization are 4.0 and 33 degrees c respectively. aeration was quite beneficial to decolorization. medium composition and the conc ... | 2001 | 11723935 |
| cloned and expressed fungal phya gene in alfalfa produces a stable phytase. | the phya gene from aspergillus ficuum that codes for a 441-amino-acid full-length phosphomonoesterase (phytase) was cloned and expressed in medicago sativa (alfalfa) leaves. the expressed enzyme from alfalfa leaves was purified to homogeneity and biochemically characterized, and its catalytic properties were elucidated. the expressed phytase in alfalfa leaves retained all the biochemical properties of the benchmark a. ficuum phytase. although the characteristic bi-hump ph optima were retained in ... | 2002 | 11812011 |
| microbial production of extra-cellular phytase using polystyrene as inert solid support. | aspergillus ficuum tub f-1165 and rhizopus oligosporus tub f-1166 produced extra-cellular phytase during solid-state fermentation (ssf) using polystyrene as inert support. maximal enzyme production (10.07 u/g dry substrate (u/gds) for a. ficuum and 4.52 u/gds for r. oligosporus) was observed when ssf was carried out with substrate ph 6.0 and moisture 58.3%, incubation temperature 30 degrees c, inoculum size of 1.3 x 10(7) spores/5 g substrate, for 72 h for a. ficuum and with substrate ph 7.0 and ... | 2002 | 12094799 |
| phya gene product of aspergillus ficuum and peniophora lycii produces dissimilar phytases. | phya gene products of aspergillus ficuum (af) and peniophora lycii (pl) as expressed in industrial strains of aspergillus niger and aspergillus oryzae, respectively, were purified to homogeneity and then characterized for both physical and biochemical properties. the pl phytase is 26 amino acid residues shorter than the af phytase. dynamic light scattering studies indicate that the active af phytase is a monomer while the pl phytase is a dimer. while both of the phytases retained four identical ... | 2003 | 12659840 |
| polyvalent cation effects on myo-inositol hexakis dihydrogenphosphate enzymatic dephosphorylation in dairy wastewater. | information is needed on organic polyphosphates such as myo-inositol 1,2,3,5/4,6-hexakis dihydrogenphosphate or phytate (ip6) contribution to the sources and sinks of dissolved phosphorus (po4-p) in the soil-manure-water system. effects of na+, ca2+, al3+, and fe3+ and cation to ip6-p mole ratios on the enzymatic dephosphorylation of ip6 were studied to determine controlling mechanisms of dephosphorylation and persistence in manure. phytate- and po4-p were analyzed by high-performance liquid chr ... | 2003 | 12708695 |
| optimization of phytase production by solid substrate fermentation. | the production of phytase by three feed-grade filamentous fungi ( aspergillus ficuum nrrl 3135, mucor racemosus nrrl 1994 and rhizopus oligosporus nrrl 5905) on four commonly used natural feed ingredients (canola meal, cracked corn, soybean meal, wheat bran) was studied in solid substrate fermentation (ssf). a. ficuum nrrl 3135 had the highest yield [15 iu phytase activity/g dry matter (dm)] on wheat bran. by optimizing the supplementation of wheat bran with starch and (nh(4))(2)so(4), phytase p ... | 2003 | 12715256 |
| fungal phya gene expressed in potato leaves produces active and stable phytase. | fungal phya gene from aspergillus ficuum (niger) was cloned and expressed in potato leaves. the recombinant enzyme was stable and catalytically active. the expressed protein in the leaves of the dicotyledonous plant retained most physical and catalytic properties of the benchmark a. ficuum phytase. the expressed enzyme was, however, 15% less glycosylated than the native phytase. the usual bi-hump ph optima profile, which is characteristic of the fungal phytase, was altered; however, the ph optim ... | 2003 | 12804608 |
| decolourization of reactive brilliant blue kn-r by immobilized cells of aspergillus ficuum. | aspergillus ficuum was immobilized with sodium alginate, and decolourization of reactive brilliant blue kn-r was studied on immobilized and free aspergillus ficuum. the optimal preparation condition of the strain immobilization was obtained by the orthogonal test, it is sodium alginate 3%, cacl2 5%, wet mycelia 30 g/l, calcific time 8 h. it was found that the immobilized cells could effectively decolourize reactive brilliant blue kn-r, the optimum temperature and ph were 33 degrees c and 5.0, re ... | 2003 | 12938990 |
| trp17 and glu20 residues in conserved wmn(d/e)pn motif are essential for aspergillus ficuum endoinulinase (ec 3.2.1.7) activity. | the importance of the wmn(d/e)pn motif, which is well conserved among beta-fructofuranosidases grouped in the glycosylhydrolase family 32, in aspergillus ficuum endoinulinase was accessed. each mutant enzyme generated by site-directed mutagenesis of trp17 in the conserved motif to gln, leu, ser, pro, thr, or met had an activity of less than 1% of the wild type. another mutant enzyme obtained by mutation of glu20 in the motif to ser, leu, thr, gln, ala, or val had an enzyme activity of less than ... | 2003 | 12943511 |
| decolorization of anthraquinone dye by aspergillus ficuum in various physiological states. | decolorization of reactive brilliant blue kn-r by aspergillus ficuum was investigated on suspended spores, mycelial pellets, immobilized cells. it was found that aspergillus ficuum could effectively decolorize reactive brilliant blue kn-r especially when grown as pelleted mycelia. many factors affecting the decolorization process in nitrogen-limited media (nlm) were studied, including: initial ph, temperature, and mycelial age. results showed that the media containing reactive brilliant blue kn- ... | 2003 | 12974461 |
| separation and identification of exo- and endoinulinase from aspergillus ficuum. | a new and convenient method was developed to separate and identify exo- and endoinulinase from aspergillus ficuum by native polyacrylamide gel electrophoresis. eight protein bands were obtained. three bands were identified as exoinulinase, and two bands were endoinulinase, by using tlc and hplc. the five bands were all detected as glycoproteins with the sensitive periodic acid-silver stain. | 2003 | 14506856 |
| organic ligand effects on enzymatic dephosphorylation of myo-inositol hexakis dihydrogenphosphate in dairy wastewater. | animal manure contains partially digested feed fiber and grains where phosphorus (p) is bound in organic compounds that include myo-inositol 1,2,3,5/4,6-hexakis dihydrogenphosphate or phytic acid (ip6). information is needed on the effects of other (non-ip6) organic ligands (lignd) on the enzymatic dephosphorylation of ip6, which is a potential source of dissolved orthophosphate p (po4-p) in the soil-manure-water system. the effects of 1,2-cyclohexane diamino-tetraacetate (cdta), diethylenetriam ... | 2004 | 14964390 |
| supplementation effect of ectoine on thermostability of phytase. | in this study, we elucidated the supplementation effect of compatible solutes on the thermostability of phytase, designated as phya ii, which was encoded by the phytase gene phya i (genebank ay013315) from aspergillus ficuum as3.324 and expressed in pichia pastoris gs115. when phya ii in acetate buffer was heated at 90 degrees c for 15 min, more than 80% of the residual activity was retained by adding the cyclic amino acid ectoine, a representative compatible solute. furthermore, the presence of ... | 2006 | 17270722 |
| molecular cloning, and characterization of a modular acetyl xylan esterase from the edible straw mushroom volvariella volvacea. | a new volvariella volvacea gene encoding an acetyl xylan esterase (designated as vvaxe1) was cloned and expressed in pichia pastoris. the cdna contained an orf of 1047 bp encoding 349 amino acids with a calculated mass of 39 990 da. vvaxe1 is a modular enzyme consisting of an n-terminal signal peptide, a catalytic domain, and a cellulose-binding domain. the amino acid sequence of the enzyme exhibited a high degree of similarity to cinnamoyl esterase b from penicillium funiculosum, and acetyl xyl ... | 2007 | 17623028 |
| purification and characterization of xylanase from aspergillus ficuum af-98. | the purification and characterization of xylanase from aspergillus ficuum af-98 were investigated in this work. the extracellular xylanase from this fungal was purified 32.6-fold to homogeneity throughout the precipitation with 50-80% (nh(4))(2)so(4), deae-sephadex a-50 ion exchange chromatography and sephadex g-100 chromatography. the purified xylanase (specific activity at 288.7 u/ mg protein) was a monomeric protein with a molecular mass of 35.0 kda as determined by sds-page. the optimal temp ... | 2008 | 18068974 |
| dephosphorylation and quantification of organic phosphorus in poultry litter by purified phytic-acid high affinity aspergillus phosphohydrolases. | extracellular phosphohydrolases mediate the dephosphorylation of phosphoesters and influence bioavailability and loss of agricultural p to the environment to pose risks of impairment of sensitive aquatic ecosystems. induction and culture of five strains of aspergillus were conducted to develop a source of high-affinity and robust phosphohydrolases for detecting environmental p and quantifying bioactive p pools in heterogeneous environmental specimens. enzyme stability and activity against organi ... | 2008 | 18555509 |
| hydrolysis of inulin: a kinetic study of the reaction catalyzed by an inulinase from aspergillus ficuum. | a kinetic study of the hydrolysis of inulin was performed by using as catalyst a commercial inulinase from aspergillus ficuum. the reaction was studied carrying out initial rate as well as time course measurements. both inulinase and invertase activities of the enzyme were taken into account, and the corresponding kinetic parameters were determined in the temperature range 30-50 degrees c. the activation energies of the turnover constant for inulinase and invertase activities were found to be si ... | 1991 | 18600646 |
| controlled production of fructose by an exoinulinase from aspergillus ficuum. | an exoinulinase has been isolated, purified and characterised from a commercially available broth of aspergillus ficuum. the enzyme was purified 4.2-fold in a 21% yield with a specific activity of 12,300 u mg(-1)(protein) after dialysis, ammonium sulphate fractionation and sephacryl s-200 size exclusion and ion exchange chromatography. the molecular weight of this enzyme was estimated to be 63 kda by sds-page. it exhibited a ph and temperature optima of 5.4 and 50 degrees c respectively and unde ... | 2009 | 19127444 |
| functional analysis of an aspergillus ficuum phytase gene in saccharomyces cerevisiae and its root-specific, secretory expression in transgenic soybean plants. | phytases release inorganic phosphates from phytate in soil. a gene encoding phytase (afphya) was isolated from aspergillus ficuum and its ability to degrade phytase and release phosphate was demonstrated in saccharomyces cerevisiae. a promoter from the arabidopsis pky10 gene and the carrot extensin signal peptide were used to drive the root-specific and secretory expression of the afphya gene in soybean plants. the phytase activity and inorganic phosphate levels in transgenic soybean root secret ... | 2009 | 19357813 |
| phytase gene expression in lactobacillus and analysis of its biochemical characteristics. | a 1.4-kb dna containing the coding region of phytase gene from aspergillus ficuum (a. ficuum) was connected with the plasmid of piabeta8 to construct shuffling vector, which was inserted into lactobacillus casei (l. casei) by electroporation. the lactobacillus with phytase gene was selected and incubated in anaerobic liquid medium. the results indicated that the highest phytase activities in the supernatant and cells were 22.12 and 4.49 uml(-1) (p<0.05) at the fourth day of incubation; the optim ... | 2010 | 19717291 |
| vinegar production residue as substrates for phytase production by aspergillus ficuum. | two kinds of vinegar production residues, sorghum vinegar residue (svr) and corn vinegar residue (cvr), were used as a substrate for phytase production in solid-state fermentation (ssf) by aspergillus ficuum. various process parameters influencing phytase production were evaluated by single factor design experiments; further study involved cvr and its goodness-of-fit levels. an incubation time of 48 hours, initial moisture of 55% and an inoculum of 1.2 x 10(7) spores per millilitre were the opti ... | 2010 | 19748935 |
| purification, characterization, and cloning of a novel phytase with low ph optimum and strong proteolysis resistance from aspergillus ficuum ntg-23. | a novel phytase was isolated from aspergillus ficuum ntg-23 with a procedure involving ion-exchange chromatography on deae-cellulose, cm-cellulose and fplc-gel filtration on superdex 75. the protein exhibited a molecular mass of 65.5kda in gel filtration and sds-page. it possessed an optimal ph of 1.3 and an optimal temperature of 67 degrees c, and manifested a k(m) of 0.295mm and a v(max) of 55.9nmol (phosphate)/min. phytase activity was not significantly affected by metal ions such as ca(2+), ... | 2010 | 20144543 |
| a large scale enzyme screen in the search for new methods of silicon-oxygen bond formation. | biotransformations make use of biological systems to catalyze or promote specific chemical reactions. transformations that utilize enzymes as "greener" and milder catalysts compared to traditional reaction conditions are of particular interest. recently, organosilicon compounds have begun to be explored as non-natural enzymatic substrates for biotransformations. the aims of this study were to screen readily available (approximately eighty) enzymes for their ability to catalyze in vitro siloxane ... | 2010 | 21194627 |
| waste vinegar residue as substrate for phytase production. | waste vinegar residue, the by-product of vinegar processing, was used as substrate for phytase production from aspergillus ficuum ntg-23 in solid-state fermentation to investigate the potential for the efficient re-utilization or recycling of waste vinegar residue. statistical designs were applied in the processing of phytase production. first, a plackett-burman (pb) design was used to evaluate eleven parameters: glucose, starch, wheat bran, (nh(4))(2)so(4), nh(4)no(3), tryptone, soybean meal, m ... | 2011 | 21447611 |
| Effect of colour LEDs on mycelia growth of Aspergillus ficuum and phytase production in photo-fermentations. | Aspergillus ficuum grown on plates and in liquid cultures were illuminated by a white fluorescent light and four different colour LED lights (white, blue, green and red) to evaluate the regulation of LED lights on fungal growth. Biomass conversion, pellet size and phytase activity were examined. In liquid culture, luminous intensity was highly correlated with the rate of biomass conversion but did not affect pellet size. The white fluorescent light contained several different wavelengths, and th ... | 2012 | 22082775 |
| Degradation of phytate by Pichia kudriavzevii TY13 and Hanseniaspora guilliermondii TY14 in Tanzanian togwa. | The fermented cereal-based gruel togwa is used as weaning food for children in Tanzania. Togwa is rich in minerals but these are often not available for uptake in the human intestine due to natural inhibitors, such as phytate (IP(6)). The yeasts Pichia kudriavzevii TY13, Hanseniaspora guilliermondii TY14 and TY20, isolated from Tanzanian togwa, and selected for high phytase activity in complex yeast medium YPD, were now studied regarding their ability to degrade IP(6) in maize-based model togwa. ... | 2011 | 22112916 |
| [investigation of inulinase permolecular organization from producers of the genus aspergillus by means of some computing and experimental methods]. | the computer model for a dimer of inulinase from aspergillus ficuum is designed. the permolecular organization of inulinase from aspergillus niger is experimentally investigated. the question about the role of various inulinase forms in manifestation of their functional activity is discussed. it is shown, that in the process of inulinase dimerization when contacts between monomeric forms of the enzyme are formed, a key role belongs to the nonpolar amino acid residues. | 2015 | 26394462 |
| phytase production by aspergillus niger cfr 335 and aspergillus ficuum sga 01 through submerged and solid-state fermentation. | fermentation is one of the industrially important processes for the development of microbial metabolites that has immense applications in various fields. this has prompted to employ fermentation as a major technique in the production of phytase from microbial source. in this study, a comparison was made between submerged (smf) and solid-state fermentations (ssf) for the production of phytase from aspergillus niger cfr 335 and aspergillus ficuum sga 01. it was found that both the fungi were capab ... | 2014 | 24688383 |
| efficient secretory overexpression of endoinulinase in escherichia coli and the production of inulooligosaccharides. | endoinulinase production was achieved by heteroexpression of endoinulinase-encoding gene from aspergillus ficuum which is an eukaryotic organism in escherichia coli bl21 (de3). further analysis demonstrated that the native signal peptide existed in inu2 gene lowered the enzyme expression level. to realize extracellular accumulation of target protein and improve its expression level, native signal peptide was substituted with pelb, ompc, and pelb fusing with the native signal peptides; then, the ... | 2016 | 27000060 |
| expression of an exoinulinase gene from aspergillus ficuum in escherichia coli and its characterization. | an exoinulinase gene from aspergillus ficuum jnsp5-06 was overexpressed in escherichia coli. two exons of the exoinulinase gene were amplified separately, joined together by an overlap pcr, and expressed in e. coli. the molecular weight of the recombinant exoinulinase was estimated to be 63 kda. the k(m) and v(max) values for inulin were (7.1±0.2) mm and (1000.0±0.1) μmol/(min mg protein), respectively. the k(m) and v(max) values for sucrose were (347.6±25.9)mm and (12,037.0±801.9) μmol/(min mg ... | 2013 | 23399248 |
| aspergillus ficuum phytase activity is inhibited by cereal grain components. | in the current study, we report for the first time that grain components of barley, rice, wheat and maize can inhibit the activity of aspergillus ficuum phytase. the phytase inhibition is dose dependent and varies significantly between cereal species, between cultivars of barley and cultivars of wheat and between fusarium graminearum infected and non-infected wheat grains. the highest endpoint level of phytase activity inhibition was 90%, observed with grain protein extracts (gpe) from f. gramin ... | 2017 | 28472144 |
| in silico design of high-affinity ligands for the immobilization of inulinase. | using computer modeling, virtual screening of high-affinity ligands for immobilization of inulinase - an enzyme that cleaves inulin and fructose-containing polymers to fructose - has been performed. the inulinase molecule from aspergillus ficuum (pdb: 3sc7) taken from the database of protein structures was used as a protein model and the target for flexible docking. the set of ligands studied included simple sugars (activators, inhibitors, products of enzymatic catalysis), as well as high-molecu ... | 2016 | 26945599 |
| optimization of phytase production from potato waste using aspergillus ficuum. | solid-state fermentation (ssf) can divert food waste from landfills and produce high-value products. this study was aimed to investigate the feasibility of using ssf and optimize the conditions of production of phytase by aspergillus ficuum from potato waste. different parameters including ph of the potato waste, inoculum level, moisture content, incubation period, temperature, and supplementary nitrogen and carbon sources were evaluated. the results indicated that ph, inoculum level, and moistu ... | 2016 | 28330328 |
| enhanced aspergillus ficuum phytase production in fed-batch and continuous fermentations in the presence of talcum microparticles. | this study aimed to enhance aspergillus ficuum phytase production in fed-batch and continuous fermentations with addition of talcum microparticles. phytase activity almost doubled in fed-batch and continuous fermentations by addition of 15 g/l of talcum compared to the control. effect of talcum on fungal morphology was also shown that addition of talcum provided smaller fungal pellets and more homogenized fermentation broth compared to the control. average fungal pellet radius decreased from 500 ... | 2015 | 25732541 |
| microparticle-enhanced aspergillus ficuum phytase production and evaluation of fungal morphology in submerged fermentation. | phytase can be used in animal's diets to increase the absorption of several divalent ions, amino acids and proteins and to decrease the excessive phosphorus release in manure to prevent negative effects on the environment. this study aimed to enhance the current submerged fungal phytase productions with a novel fermentation technique by evaluating the effect of the various microparticles on aspergillus ficuum phytase production. it was observed that microparticles prevented bulk fungal pellet gr ... | 2015 | 25555703 |
| production and partial purification of tannase from aspergillus ficuum gim 3.6. | a novel fungal strain, aspergillus ficuum gim 3.6, was evaluated for its tannase-producing capability in a wheat bran-based solid-state fermentation. thin-layer chromatography (tlc) analysis revealed that the strain was able to degrade tannic acid to gallic acid and pyrogallol during the fermentation process. quantitation of enzyme activity demonstrated that this strain was capable of producing a relatively high yield of extracellular tannase. single-factor optimization of process parameters res ... | 2015 | 25126886 |
| enhanced submerged aspergillus ficuum phytase production by implementation of fed-batch fermentation. | phytase is an important feed and food additive, which is both used in animal and human diets. phytase has been used to increase the absorption of several divalent ions, amino acids, and proteins in the bodies and to decrease the excessive phosphorus release in the manure to prevent negative effects on the environment. to date, microbial phytase has been mostly produced in solid-state fermentations with insignificant production volumes. there are only a few studies in the literature that phytase ... | 2014 | 24958522 |
| asparagine 42 of the conserved endo-inulinase inu2 motif wmndpn from aspergillus ficuum plays a role in activity specificity. | endo-inulinase inu2 from aspergillus ficuum belongs to glycosidase hydrolase family 32 (gh32) that degrades inulin into fructo oligosaccharides consisting mainly of inulotriose and inulotetraose. the 3d structure of inu2 was recently obtained (pouyez et al., 2012, biochimie, 94, 2423-2430). an enlarged cavity compared to exo-inulinase formed by the conserved motif w-m(i)-n-d(e)-p-n-g, the so-called loop 1 and the loop 4, was identified. in the present study we have characterized the importance o ... | 2013 | 24251113 |
| screening of phytase producers and optimization of culture conditions for submerged fermentation. | phytase (myo-inositol-hexakisphosphate phosphohydrolase) is an enzyme, which breaks down phytate to inositol and orthophosphoric acid. phytase has been used as feed additive, and in some medical applications for years. to date, phytase production has been usually performed as a solid-state fermentation with small production volumes. therefore, the aim of this study was to increase the phytase activity in submerged fermentations by screening several microorganism strains based on the literature t ... | 2014 | 23943047 |
| efficiency of phosphorus utilization in phya-expressing cotton lines. | to evaluate and characterize the stability of traits conferred by phya from aspergillus ficuum, we examined expression of phya in sexually-derived transgenic cotton progeny and assessed the capacity for phytate-utilization in t4 progeny. the gene (phya) was expressed only in the roots, but not in the stem and leaf tissues. phytase activity was 2.38-fold higher in transgenic line l2 than in wild-type (wt) plants. the amount of phosphorus in the leaves was also significantly higher in transgenic l ... | 2012 | 23077786 |
| beneficial effect of protracted sterilization of lentils on phytase production by aspergillus ficuum in solid state fermentation. | water addition to the solid substrate preceding autoclaving increased substrate porosity and phytase production in solid state fermentation. in comparison with dry sterilization, the phytase activity increased 6-, 8.5-, and 10-fold when the autoclaving time was 20, 40, and 60 min, respectively. autoclaving increased the void space of sterilized lentils, and the increase was 16% higher when water was supplemented to the lentils before sterilization. image analysis of sem pictures of the solid sub ... | 2012 | 22848026 |
| first crystal structure of an endo-inulinase, inu2, from aspergillus ficuum: discovery of an extra-pocket in the catalytic domain responsible for its endo-activity. | endo-inulinase is a member of glycosidase hydrolase family 32 (gh32) degrading fructans of the inulin type with an endo-cleavage mode and is an important class of industrial enzyme. in the present study, we report the first crystal structure of an endo-inulinase, inu2, from aspergillus ficuum at 1.5 å. it was solved by molecular replacement with the structure of exo-inulinase as search model. the 3d structure presents a bimodular arrangement common to other gh32 enzymes: a n-terminal 5-fold β-pr ... | 2012 | 22750808 |