| biological activity of ukrain in vitro and in vivo. | | 1987 | 3334662 |
| trapping of different lipase conformers in water-restricted environments. | based on a recently reported strategy to rationally activate lipolytic enzymes for use in nonaqueous media [mingarro, i., et al. (1995) proc. natl. acad. sci. u.s.a. 92, 3308-3312], we compared the behavior in water-restricted environments of activated vs nonactivated forms of different lipases toward their natural substrates, triacylglycerols. to this end, nine lipases from varied origins (mammalian, fungal, and bacterial) were assayed using simple acidolyses as nonaqueous model reactions. the ... | 1996 | 8703968 |
| efficacy of phytase in improving the bioavailability of phosphorus in soybean meal and corn-soybean meal diets for pigs. | four experiments involving 225 pigs were conducted to assess the efficacy of a microbial phytase (finase, alko ltd. biotechnology, rajamäki, finland) produced by aspergillus niger in corn-soybean meal or dextrose-cornstarch-soybean meal-based diets. in two experiments with growing-finishing pigs, fortified corn-soybean meal diets were formulated to be adequate (.50%) or inadequate (.40 or .30%) in p during the growing phase followed by adequate (.40%) or inadequate (.30%) p in the finishing phas ... | 1993 | 8394307 |
| nonaldehyde sterilization of biologic tissue for use in implantable medical devices. | biologic tissue stabilized by dye-mediated photooxidation has found application in implantable devices. the desire to avoid aldehydes in the processing of photooxidized tissues led to the development of a nonaldehyde, iodine based sterilant. the interaction of tissue with iodine was indicated by a change in tissue shrinkage temperature, dependent upon solution and incubation parameters. the amino acid tyrosine also was altered, presumably because of aromatic ring iodination. transmission electro ... | 1997 | 9116349 |
| interaction of phlorizin, a potent inhibitor of the na+/d-glucose cotransporter, with the nadph-binding site of mammalian catalases. | phlorizin is a reversible inhibitor of the renal and small intestinal na+/d-glucose cotransporter. in an attempt to purify the na+/d-glucose cotransporter from a pig kidney brush border membrane fraction, we used an affi-gel affinity chromatography column to which 3-aminophlorizin had been coupled. a protein, composed according to crosslinking experiments of at least 3 subunits of molecular weight 60 kda, was found to bind specifically to the phlorizin column. this protein was subsequently ident ... | 1994 | 8003987 |
| [the decomposition of maillard reaction products by amylolytic enzymes. 1. reversible inhibition of alpha- and glucoamylase and alpha-glucosidase by oligosaccharide amidori compounds]. | the influence of amadori-compounds (fructosyl-, maltulosyl- and maltotriulosylglycin) on the activity of the enzymes alpha-glucosidase (from saccharomyces cerevisiae), glucoamylase (from aspergillus niger) and alpha-amylase (from porcine pancreas) was studied. fructosylglycin was not hydrolyzed by all three enzymes. alpha-glucosidase hydrolyzes maltulosylglycin 10 times slower than maltotriulosylglycin. glucoamylase and alpha-amylase catalyze only the cleavage of maltotriulosylglycin to form glu ... | 1994 | 7839734 |
| supplementing corn-soybean meal diets with microbial phytase linearly improves phytate phosphorus utilization by weanling pigs. | two experiments were conducted with weanling pigs to determine the effectiveness of a dietary supplement of aspergillus niger phytase in improving the availability of phytate-p in corn-soybean meal diets without supplemental inorganic p. experiment 1 consisted of two p and ca balance trials and two feeding trials. twelve pigs (8.18 +/- .44 kg bw) were housed individually in stainless steel metabolism cages. six pigs received 750 phytase units (pu)/g of basal diet and the other six pigs received ... | 1993 | 8294288 |
| efficacy of low-activity, microbial phytase in improving the bioavailability of phosphorus in corn-soybean meal diets for pigs. | two experiments involving 115 pigs were conducted to assess the efficacy of a microbial phytase (allzyme phytase; alltech, nicholasville, ky) produced by aspergillus niger in low-p, corn-soybean meal-based diets. the phytase supplement contained 50 phytase units/g and 1.43% p. in exp. 1, growing-finishing pigs were fed fortified corn-soybean meal diets formulated to be adequate (.50%) or inadequate (.30%) in p during the growing phase (38 to 57 kg bw) followed by adequate (.40%) or inadequate (. ... | 1995 | 7601778 |
| efficacy of a recombinant-derived phytase in improving the bioavailability of phosphorus in corn-soybean meal diets for pigs. | three experiments involving 162 pigs were conducted to assess the efficacy of phytase (natuphos; basf, mount olive, nj) in low-p, corn-soybean meal-based diets. the phytase was produced by a recombinant aspergillus niger. the phytase supplement contained 5,000 phytase units (ptu)/g. in exp. 1 (66 pigs) and 2 (60 pigs), growing-finishing pigs were fed fortified corn-soybean meal diets formulated to be adequate (.50%), marginal (.425%), or inadequate (.35%) in p during the growing phase (23 to 60 ... | 1995 | 7592084 |
| actions of porcine pancreatic and bacillus subtilis alpha-amylases and aspergillus niger glucoamylase on phosphorylated (1--4)-alpha-d-glucan. | porcine pancreatic alpha-amylase (1,4-alpha-d-glucan glucanohydrolase, ec 3.2.1.1) produced o-6-phosphoryl-alpha-d-glucopyranosyl-(1--4)-o-alpha-d-glucopyranosyl -(1--4)-d-glucopyranose (6(3)-phosphoryl maltotriose) and o-alpha-d-glucopyranosyl-(1--4)-o-alpha-d-glucopyranosyl- o-3-phosphoryl-alpha-d-glucopyranosyl-(1--4)-d-glucopyranose (3(2)-phosphoryl maltotetraose) from potato starch upon exhaustive hydrolysis, while bacillus subtilis alpha-amylase (liquefying type) yielded o-alpha-d-glucopyr ... | 1983 | 6419777 |
| [synthesis and properties of digitoxigenin-3 beta-o-alpha-l-arabinofuranoside]. | the synthesis of a cardenolide glycoside with a furanoide sugar component, digitoxigenin-3 beta-o-alpha-l-arabinofuranoside (4), is described for the first time. 4 was prepared by the reaction of digitoxigenin with 2,3,5-tri-o-benzoyl-alpha-l-arabinofuranosylchloride and fétizon-reagent in benzene/dioxan followed by debenzoylation with ammonia in dry methanol. compound 4 is cleaved by alpha-l-arabinofuranosidase (aspergillus niger k1) into digitoxigenin and l-arabinose. hydrolytic stability agai ... | 1982 | 6298840 |
| supplementing corn-soybean meal diets with microbial phytase maximizes phytate phosphorus utilization by weanling pigs. | two experiments were conducted with crossbred weanling pigs to determine the optimal dietary supplement of aspergillus niger phytase activity to a low-p, corn-soybean meal basal diet (bd). in exp. 1, 50 pigs (7.61 +/- .56 kg bw) received the bd supplemented with 750, 1,050, 1,250, or 1,350 phytase units (pu)/g, or .21% p as mono-dibasic calcium phosphate (mdcap) for 4 wk. in exp. 2, 12 pigs (6.39 +/- .74 kg bw) were individually housed in metabolism cages and received bd, bd plus the optimal phy ... | 1993 | 8294289 |
| stereochemical studies of d-glucal hydration by alpha-glucosidases and exo-alpha-glucanases: indications of plastic and conserved phases in catalysis by glycosylases. | alpha-glucosidases from aspergillus niger, pig serum, ungerminated rice, buckwheat, and sugar beet seeds (but not from brewers' yeast or honeybee) were found to catalyze the hydration of d-glucal. each reactive alpha-glucosidase, incubated with d-glucal in d2o, was shown to protonate (deuteriate) this prochiral substrate from above its re face, i.e., from a direction opposite that assumed for protonating alpha-d-glucosidic substrates. at the same time, d-glucal hydration catalyzed by three of th ... | 1988 | 3284583 |
| purification of glucoamylase by acarbose (bay g-5421) affinity chromatography. | aspergillus niger and rhizopus sp. glucoamylases were purified on an affinity chromatography column from commercially available, impure enzyme preparations. up to 2 mg of glucoamylase protein was bound without leakage to a 1-ml affinity gel column (0.7 x 2.5 cm) possessing a covalently linked acarbose ligand (1 mg acarbose/g wet gel), and the bound enzyme was specifically released by irrigation of the column with a solution of maltose. a complete cycle of purification was accomplished in about 8 ... | 1986 | 3091050 |
| 8-azidoflavins as photoaffinity labels for flavoproteins. | 8-azidoflavins have been synthesized and their potential as photoaffinity labels for flavoproteins has been explored. they are very photolabile, and in aqueous media they react with solvent to yield 8-aminoflavins and 8-hydroxlaminoflavins as the main products. they fulfill the criteria expected of a good photoaffinity label, since they bind stoichiometrically at the flavin-binding site of flavoproteins, thus minimizing problems of nonspecific labeling. second, they absorb strongly in the visibl ... | 1985 | 2861204 |
| formation of a stable l-ascorbic acid alpha-glucoside by mammalian alpha-glucosidase-catalyzed transglucosylation. | enzymatic transglucosylation from maltose to l-ascorbic acid (aa) with mammalian tissue homogenates was determined by a high-performance liquid chromatography method and compared with the reaction catalyzed by alpha-glucosidase from aspergillus niger. the homogenates of small intestine and kidney had a high transglucosylase activity to form a new type of glucosylated aa, which was associated with alpha-glucosidase activity. the new compound was demonstrated to be an equimolar conjugate of aa and ... | 1990 | 2200520 |
| [evaluation of aspergillus niger phytase and phosphate in weaned piglets. 2. content and gain of fat, energy, ash, ca and p in the animal body]. | a high phytic acid diet (barley, wheat, soya bean meal, 4 g p/kg diet, of that 2/3 phytate p) without added phytase, with phytase supplement (1000 u/kg diet) or with supplementary phosphate (2.2 g p/kg diet) was examined with 3 x 12 weaned piglets. the three diets contained 8 g ca/kg. at the end of experiment 6 pigs/group were slaughtered. in animal body (as empty body) the content and gain of ash, p, ca, protein and fat were detected. p supplementation and supplementary phytase had no effect on ... | 1995 | 7668982 |
| use of monoclonal antibodies, enzyme-linked immunosorbent assay and immunoaffinity column chromatography to determine ochratoxin a in porcine sera, coffee products and toxin-producing fungi. | ochratoxin a, produced by a number of fungal species, has been found in many milieu, including porcine sera and coffee beans. it was therefore analysed by enzyme-linked immunosorbent assay (elisa) in porcine sera, coffee products and fungal cultures, using monoclonal antibodies, a monoclonal antibody-linked immunoaffinity column (iac) and high-performance liquid chromatography (hplc). the chloroform extracts of acidified porcine sera were assayed directly by elisa, with alkaline phosphatase and ... | 1991 | 1820356 |
| heterologous gene expression in aspergillus niger: a glucoamylase-porcine pancreatic prophospholipase a2 fusion protein is secreted and processed to yield mature enzyme. | the cdna gene encoding porcine pancreatic prophospholipase a2 (propla2) was cloned into an aspergillus niger expression vector downstream of the glucoamylase (glaa) gene promoter region. when this construct was transformed into a. niger, no detectable pla2 was produced. 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 deg ... | 1992 | 1452022 |
| the effect of supplementary aspergillus niger phytase in diets for pigs on concentration and apparent digestibility of dry matter, total phosphorus, and phytic acid in different sections of the alimentary tract. | six barrows of approximately 37 kg bw, fitted with two simple t-cannulas in the duodenum (25 cm posterior to the pylorus) and terminal ileum (12 to 15 cm anterior to the ileocecal junction), were fed two diets containing 2.1 g of p/kg in the form of phytic acid and a low intrinsic phytase activity (corn-soybean meal based diet [diet a] or a typical dutch diet [diet b]) without or with supplementary microbial phytase from aspergillus niger (var. ficuum) equal to 1,500 phytase units per kilogram o ... | 1992 | 1316345 |
| phytase. | of all the sources of phytase that have been studied (plant, animal, and microorganisms), the highest yields are produced by a wild-type strain a. niger nrrl 3135 (12.7 mg p/hr/ml = 6.8 microns p/ml/min = 113.9 nkat/ml) in a mineral salt medium in which total phosphate (4 mg %) is limiting for growth and cornstarch and glucose are the carbon sources. synthesis of the enzyme is repressed by phosphate in the wild-type strain. aspergillus niger nrrl 3135 produces two phytases one with ph optima at ... | 1996 | 8865587 |
| effect of microbial phytase on cadmium accumulation in pigs. | 2 x 6 pigs continuously housed in metabolic cages from 25-100 kg weight were fed n-reduced diets based on barley, maize and soybean meal. diet i (control) contained in fm (fresh matter) 0.56%, 0.48% and 0.46% p (feeding phases a: 25-50 kg, b: 50-75 kg, c: 75-100 kg weight) and 0.76%, 0.71% and 0.68% ca. diet ii was low in p (0.46%, 0.40%, 0.32%) and ca (0.69%, 0.62%, 0.52%) and 800 u aspergillus-phytase per kg were added. analyzed cadmium concentrations in diet i were 23.4, 19.9 and 13.7 microgr ... | 1996 | 8988314 |
| supplemental microbial phytase improves bioavailability of dietary zinc to weanling pigs. | two experiments were conducted to determine the effects of supplemental microbial phytase on utilization of dietary zinc by weanling pigs. experiment 1 was a 2 x 3 factorial arrangement of treatments with 24 pigs for 4 wk. two levels of phytase activity (0 and 1350 units/g) and three levels of zinc (0, 30 and 60 mg/kg as znso4.7h2o) were added to a corn-soybean meal basal diet. weekly measures included growth performance, plasma alkaline phosphatase activity and plasma mineral concentrations. in ... | 1993 | 8389400 |
| supplemental phytases of microbial and cereal sources improve dietary phytate phosphorus utilization by pigs from weaning through finishing. | this experiment was conducted to measure the nutritional and metabolic responses of pigs fed diets with continuous supplementation of microbial and cereal phytase from weaning to finishing, and to determine the feasibility of complete replacement of inorganic p addition by supplemental phytase in swine diets. forty-eight landrace x hampshire x meishan pigs were divided into four groups. in phase 1 (10 to 50 kg bw), pigs in groups 1, 2, 3, and 4 were fed a low-p, corn-soybean meal basal diet (bd) ... | 1997 | 9110215 |
| microbial/enzymatic synthesis of chiral drug intermediates. | biocatalytic processes were used to prepare chiral intermediates for pharmaceuticals. these include the following processes. enzymatic synthesis of [4s-(4a,7a,10ab)]1-octahydro-5-oxo-4-[[(phenylmethoxy) carbonyl]amino]-7h-pyrido-[2,1-b] [1,3]thiazepine-7-carboxylic acid methyl ester (bms-199541-01), a key chiral intermediate for synthesis of a new vasopeptidase inhibitor. enzymatic oxidation of the epsilon-amino group of lysine in dipeptide dimer n2-[n[[(phenylmethoxy)carbonyl] l-homocysteinyl] ... | 2000 | 12876794 |
| soaking increases the efficacy of supplemental microbial phytase in a low-phosphorus corn-soybean meal diet for growing pigs. | sixty-three crossbred barrows averaging 18.7 kg initial bw were used in a 6-wk study of the effects of soaking on the efficacy of supplemental microbial phytase (natuphos, basf) in a low-p corn-soybean meal diet. the basal corn-soybean meal diet contained .06% available p, .32% total p, and .55% ca with no added inorganic p. the basal diet was supplemented with 0, 250, or 500 phytase units (pu)/kg of diet. the diet was fed dry or soaked (2 parts water:1 part diet and mixed for 2 h at 30 degrees ... | 1997 | 9159276 |
| purification and characterization of an extracellular aspartic proteinase from aspergillus fumigatus. | an aspartic proteinase (pep) from the culture supernatant of a clinical isolate of aspergillus fumigatus was purified to virtual homogeneity at a yield of 24%. the procedure involved affinity chromatography on pepstatin agarose, the interaction requiring a chaotropic salt (sodium trifluoroacetate) for complete elution of the enzyme. among 11 amino acids of the n-terminal region, nine were identical with the corresponding sequence of the aspartic proteinase aspergillopepsin a from aspergillus nig ... | 1994 | 7738725 |
| monoclonal antibodies to mitochondrial f1-atpase and oligomycin sensitivity conferring protein (oscp). tools for recognition of well conserved and essential antigenic sites. | the preparation of anti-oscp monoclonal antibodies is described for the first time. one of these antibodies prevents the activating effect of oscp in reconstitution experiments. these antibodies and antibodies previously obtained against the alpha- and beta-subunits of pig heart mitochondrial f1-atpase have been used to look for well conserved epitopes in various species. one anti-beta antibody can recognize all species tested while the anti-oscp antibodies only recognize the pig or beef enzyme. ... | 1984 | 6206858 |
| the efficacy of aspergillus niger phytase in rendering phytate phosphorus available for absorption in pigs is influenced by pig physiological status. | we performed an experiment with 112 piglets, 32 growing-finishing pigs, and 12 sows during pregnancy and lactation to test the hypotheses that apparent total tract digestibilities of p and ca as well as the efficacy of aspergillus niger phytase in rendering phytate p available in pigs depend on pig physiological status. all pigs were fed diets with identical feedstuff composition either without or with added microbial phytase (natuphos, 500 ftu/kg diet). the diets contained 6.2 g ca, 4.8 g total ... | 1997 | 9263060 |
| the effects of sow parity on digestibility of proximate components and minerals during lactation as influenced by diet and microbial phytase supplementation. | ninety-six (finnish landrace x dutch landrace) reproductive sows were used at parities 1, 3, 5, and 7 + 8 from d 107 of gestation to d 21 of lactation to investigate the effects of diet and parity on apparent total tract digestibility (attd). animals were randomly assigned to one of four dietary treatments. dietary treatments were 1) a p-deficient (1.1 g digestible p [dp]/kg) dutch semipractical diet; 2) diet 1 supplemented with 400 ftu aspergillus niger phytase per kilogram of diet (1.7 g dp/kg ... | 1997 | 9263062 |
| studies of lipase-catalyzed esterification reactions of some acetylenic fatty acids. | esterification of five positional isomers of acetylenic fatty acids [viz. 9:1(2a), 11:1(10a), 18:1(6a), 18:1(9a) and 22:1(13a)] of different chain lengths with n-butanol in n-hexane in the presence of eight different lipases [lipozyme im 20 (rhizomucor miehei), lipolase 100t (r. miehei), novozyme 435 (candida antarctica), ppl (porcine pancreatic lipase), ccl (c. cylindracea), ps-d (pseudomonas cepacia), lipase a-12 (aspergillus niger) and lipase ay-30 (c. rugosa)] was studied. 2-nonynoic acid wa ... | 1998 | 9470175 |
| bioelectrochemical monitoring of phenols and aromatic amines in flow injection using novel plant peroxidases. | an amperometric flow system combined with a glucose oxidase-mutarotase reactor was optimized and used to determine aromatic amines and phenols using peroxidase-modified graphite electrodes. an increase in currents upon injection of the analyzed substrate was shown to be approximated by a michaelis-menten type dependence. the detection limit was calculated as 3 times the noise, and the sensitivity was calculated as imax/k(m)app. commercially available horseradish peroxidase was compared with toba ... | 1998 | 9666727 |
| [evaluation of aspergillus niger phytase and dietary phosphate in weaned piglets. 1. growth, blood serum and bone status]. | a high phytic acid diet (barley, wheat, soya bean meal, 4 g p/kg, of that 2/3 phytate p) without added phytase, with phytase supplement (1000 u/kg diet) or with supplementary phosphate (2,2g p/kg diet) was examined with 3 x 12 weaned piglets. the high dietary p level due to phosphate addition, significantly improved body weight gain and feed:gain ratio. the phytase effect on these criteria was small. the phytase but more the supplementary phosphate increased p concentration of serum. in case of ... | 1994 | 7668974 |
| calcium level affects the efficacy of supplemental microbial phytase in corn-soybean meal diets of weanling pigs. | a 2 x 2 x 2 factorial experiment was conducted with 64 pigs (4 wk old, 8.04 +/- .50 kg bw) to determine the effect of various dietary concentrations of ca, vitamin d, and microbial phytase (aspergillus niger) on phytate-p utilization. a low-p, corn-soybean meal diet was supplemented with two levels of phytase (unit/gram), 750 (suboptimal) and 1,200 (optimal); of vitamin d (international unit/kilogram), 660 (normal) and 6,660 (high); and of ca (percentage), .4 (low) and .8 (normal). pen feed cons ... | 1994 | 8138481 |
| apparent digestibility and retention of nutrients bound to phytate complexes as influenced by microbial phytase and feeding regimen in pigs. | five barrows of approximately 45 kg bw, fitted with post-valvular t-cecum cannulas at the ileo-cecal junction, were assigned randomly to five treatments (5 x 5 latin square design) to assess the effect of microbial phytase and feeding regimen (frequency and level) on the apparent digestibilities (total tract [attd] and ileal [aid]) and retention of nutrients. a corn-tapioca-soybean meal diet of low intrinsic phytase activity, containing no added inorganic p, was fed either without or with microb ... | 1994 | 8138479 |
| biophysical characterization of fungal phytases (myo-inositol hexakisphosphate phosphohydrolases): molecular size, glycosylation pattern, and engineering of proteolytic resistance. | phytases (myo-inositol hexakisphosphate phosphohydrolases) are found naturally in plants and microorganisms, particularly fungi. interest in these enzymes has been stimulated by the fact that phytase supplements increase the availability of phosphorus in pig and poultry feed and thereby reduce environmental pollution due to excess phosphate excretion in areas where there is intensive livestock production. the wild-type phytases from six different fungi, aspergillus niger, aspergillus terreus, as ... | 1999 | 9925554 |
| cloning, sequencing, and expression of an escherichia coli acid phosphatase/phytase gene (appa2) isolated from pig colon. | bacterial strains were isolated from the pig colon to screen for phytase and acid phosphatase activities. among 93 colonies, colony 88 had the highest activities for both enzymes and was identified as an escherichia coli strain. using primers derived from the e. coli ph 2.5 acid phosphatase appa sequence (dassa et al. (1990), j. bacteriol. 172, 5497-5500), we cloned a 1482 bp dna fragment from the isolate. in spite of 95% homology between the sequenced gene and the appa, 7 amino acids were diffe ... | 1999 | 10092520 |
| validation of a viral and bacterial inactivation step during the extraction and purification process of porcine collagen. | in the last few years, regulations for biomolecule production, and especially for extraction and purification of animal molecules such as collagen, have been reinforced to ensure the sanitary safety of the materials. to be authorized to market biomaterials based on collagen, manufacturers now have to prove that at least one step of their process is described in guidelines to inactivate prion, viruses, and bacteria. the present study focuses on the inactivation step performed during the extractio ... | 2007 | 17611295 |
| the interaction of 1-fluoro-d-glucopyranosyl fluoride with glucosidases. | 1. 1-fluoro-d-glucopyranosyl fluoride undergoes ph-independent loss of f- ion at a rate of 1 x 10(-8) s-1 at 50.0 degrees c, some 10(3)-fold slower than alpha-d-glucopyranosyl fluoride and 4 x 10(4)-fold slower than beta-d-glucopyranosyl fluoride. 2. the (inverting) amyloglucosidase ii of aspergillus niger hydrolyses the difluoride according to michaelis-menten kinetics (km 34 mm and kcat. 0.27 s-1), by apparently the same (simple) mechanism by which it hydrolyses alpha-d-glucopyranosyl fluoride ... | 1991 | 1953653 |
| stability of porcine and microbial lipases to conditions that approximate the small intestine of young birds. | in vitro experiments were conducted to study the stability of lipase activities from bacterial, fungal, and animal sources under conditions that approximate the small intestine. in the first experiment, the effects of preincubation with trypsin (500, 1,000, and 2,000 u/ml), chymotrypsin (200, 400, and 800 u/ml), and trypsin plus chymotrypsin (tc; 2,000 u/ml trypsin + 800 u/inl chymotrypsin) for 30 min at 40 c, on lipase activities from sources of pseudomonas spp. (pl1, pl2), chromobacterium visc ... | 1998 | 9835342 |
| stability of porcine and microbial lipases to conditions that approximate the proventriculus of young birds. | in vitro experiments were conducted to characterize the activity and the stability of lipase from animal (crude porcine, cpl; lyophilized porcine, lpl), fungal (rhizopus arrhizus, ral; aspergillus niger, anl), and bacterial (two pseudomonas spp., pl1, pl2; and chromobacterium viscosum, cvl) sources when exposed to conditions associated with the glandular stomach. activity was measured at ph 3 to 8, 40 c and then monitored in response to temperature (40 c), time of exposure (0 and 30 min), ph (3 ... | 1998 | 9835341 |
| efficacy of yeast phytase in improving phosphorus bioavailability in a corn-soybean meal-based diet for growing pigs. | crossbred barrows (n = 66; 6 wk old) were used in a 6-wk experiment to evaluate the efficacy of phytase from yeast or aspergillus niger on performance, tibial characteristics, and serum inorganic p concentration. we also investigated the stability of these phytases in acidic solutions with pepsin, which simulated gastric conditions. pigs were fed a p-adequate diet containing .34% nonphytate-p or a low-p diet containing .20% nonphytate-p. the low-p diet was supplemented with 0, 1,000, 2,000, or 4 ... | 2000 | 10682807 |
| screening of aspergillus species for occurrence of lectins and their characterization. | ten species of aspergillus were screened for occurrence of lectins. each of the species was investigated for the occurrence of extracellular, surface-bound and intracellular lectin activities. as many as four species namely, aspergillus niger, aspergillus versicolor, aspergillus rugulosus and aspergillus nidulans, were found to possess intracellular lectin activities, while none of the species showed extracellular or surface-bound lectin activities. each of the lectin was characterized with resp ... | 2008 | 18383222 |
| penicillopepsin-jt2, a recombinant enzyme from penicillium janthinellum and the contribution of a hydrogen bond in subsite s3 to k(cat). | the nucleotide sequence of the gene (pepa) of a zymogen of an aspartic proteinase from penicillium janthinellum with a 71% identity in the deduced amino acid sequence to penicillopepsin (which we propose to call penicillopepsin-jt1) has been determined. the gene consists of 60 codons for a putative leader sequence of 20 amino acid residues, a sequence of about 150 nucleotides that probably codes for an activation peptide and a sequence with two introns that codes for the active aspartic proteina ... | 2000 | 10850809 |
| 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 |
| hydroxylation of the diterpenes ent-kaur-16-en-19-oic and ent-beyer-15-en-19-oic acids by the fungus aspergillus niger. | the diterpenes ent-kaur-16-en-19-oic acid (1) and ent-beyer-15-en-19-oic acid (2) are the major constituents of a spasmolytic diterpenic mixture obtained from the roots of viguiera hypargyrea, a mexican medicinal plant. microbial transformation of 1 and 2 was performed with aspergillus niger. two metabolites, ent-7alpha,11beta-dihydroxy-kaur-16-en-19-oic acid (4) and ent-1beta,7alpha-dihydroxy-kaur-16-en-19-oic acid (5), were isolated from the incubation of 1, and one metabolite, ent-1beta,7alph ... | 2009 | 19815245 |
| hydrolysis of phytic acid by intrinsic plant and supplemented microbial phytase (aspergillus niger) in the stomach and small intestine of minipigs fitted with re-entrant cannulas. 3. hydrolysis of phytic acid (ip6) and occurrence of hydrolysis products (ip5, ip4, ip3 and ip2). | hydrolysis of phytate in the stomach and the small intestine as influenced by intrinsic plant (wheat) and supplemented microbial phytase (aspergillus niger) were investigated with six minipigs (40-50 kg initial body weight) fitted with re-entrant cannulas in the duodenum, 30 cm posterior to the pylorus (animals 1, 4, 5 and 6) and ileocecal re-entrant cannulas, 5 cm prior the ileocecal junction (animals 1, 2 and 3), respectively. dietary treatments were as follows: (1) diet 1, a corn-based diet [ ... | 2001 | 11906566 |
| stereospecificity of an enzymatic monoene 1,4-dehydrogenation reaction: conversion of (z)-11-tetradecenoic acid into (e,e)-10,12-tetradecadienoic acid. | in this article, we report the first stereochemical study of an enzymatic 1,4-dehydrogenation reaction, namely, the transformation of (z)-11-tetradecenoic acid into (e,e)-10,12-tetradecadienoic acid, involved in the sex pheromone biosynthesis of the moth spodoptera littoralis. the investigation was carried out using the labeled substrates (r)-[10-(2)h]- and (s)-[10-(2)h]-tridecanoic acids ((r)-2 and (s)-2, respectively) and (r)-[2,2,3,3,13-(2)h(5)]- and (s)-[2,2,3,3,13-(2)h(5)]-tetradecanoic aci ... | 2002 | 11925233 |
| detection of ochratoxin a in animal feeds and capacity to produce this mycotoxin by aspergillus section nigri in argentina. | ochratoxin a (oa) is a mycotoxin detected in a variety of food and feeds mostly from countries with a temperate climate because of the fungi that produce it, mainly aspergillus ochraceus and penicillium verrucosum. in argentina, there is no available information about the natural occurrence of oa and ochratoxigenic fungi from feedstuffs. the aim was to evaluate the natural occurrence of oa in poultry, pig and rabbit feeds over 8 months. likewise, the capacity to produce oa by aspergillus section ... | 2002 | 12456278 |
| degradation of vx and sulfur mustard by enzymatic haloperoxidation. | chloroperoxidase (cpo) isolated from caldariomyces fumago (20 u ml(-1)) together with urea hydrogenperoxide (uper, 0.5 mm) and sodium chloride as co-substrate (nacl, 0.5 m) caused rapid breakdown of vx (10 microm) (t((1/2)) = 8 s, 25 c, 50 mm tartarate, ph 2.75). glucose oxidase (gox, aspergillus niger) and glucose were used as an alternative source for h(2)o(2). a mixture of gox (20 u ml(-1)), glucose (glu 0.45 m), cpo (20 u ml(-1)) and nacl (0.5 m) caused a 3.8-fold slower degradation of vx (1 ... | 2003 | 12884405 |
| inhibition of beta-fructofuranosidases and alpha-glucosidases by synthetic thio-fructofuranoside. | a synthetic beta-thio-fructofuranoside of mercaptoethanol inhibited not only beta-fructofuranosidases but also alpha-glucosidases. the compound was hardly hydrolyzed by the glycosidases. the thio-fructoside competitively inhibited beta-fructofuranosidases from aspergillus niger, candida sp., and saccharomyces cerevisiae, but not arthrobacter beta-fructofuranosidase at all. sucrase activity of rat intestinal sucrase/isomaltase complex was also suppressed in the presence of the thio-fructoside. th ... | 2003 | 12951505 |
| redox-triggered ftir difference spectra of fad in aqueous solution and bound to flavoproteins. | flavin adenine dinucleotide (fad) and three different flavoproteins in aqueous solution were subjected to redox-triggered fourier transform infrared difference spectroscopy. the acquired vibrational spectra show a great number of positive and negative peaks, pertaining to the oxidized and reduced state of the molecule, respectively. density functional theory calculations on the b3lyp/6-31g(d) level were employed to assign several of the observed bands to vibrational modes of the isoalloxazine mo ... | 2003 | 14674755 |
| effects of combining three fungal phytases with a bacterial phytase on plasma phosphorus status of weanling pigs fed a corn-soy diet. | the objective of this study was to determine possible synergistic effects of supplementing one of three fungal phytases: aspergillus fumitagus phya (afp),a. niger phya (anp), or peniophora lyci phytase (plp) with an escherichia coli appa phytase (ep) in diets for pigs. three experiments, each lasting for 4 wk, were conducted with a total of 106 weanling pigs (5 wk old). the corn-soybean meal basal diet (bd) contained no supplemental inorganic p. in exp. 1, 35 pigs (8.6 +/- 1.0 kg bw) were fed (a ... | 2004 | 15217000 |
| molecular modelling of human microsomal epoxide hydrolase (eh) by homology with a fungal (aspergillus niger) eh crystal structure of 1.8 a resolution: structure-activity relationships in epoxides inhibiting eh activity. | homology modelling of the human microsomal epoxide hydrolase (eh) enzyme based on the fungal (aspergillus niger) eh crystallographic template is reported. the active site lies in a well-defined, essentially hydrophobic, pocket within the overall enzyme structure. two tyrosine residues, that are conserved in all known mammalian eh sequences, are able to form hydrogen bonds (one per tyrosine residue) with the epoxide oxygen atom on the known eh substrate, styrene oxide. there is also a small hydro ... | 2005 | 15826809 |
| surveillance of toxigenic fungi and ochratoxin a in feedstuffs from córdoba province, argentina. | the aim of this work was to evaluate the incidence of potential ochratoxigenic mycoflora and ochratoxin a (oa) in poultry, pig and rabbit feeds. eighty poultry, pig and rabbit feed samples were taken at random from factories located from córdoba province, argentina, over a period of 8 months. isolation and quantitative enumeration of fungal propagules were done on drbc and dg18 media. the predominant species were a. candidus, a. flavus, a. terreus, a. parasiticus, p. implicatum, p. minioluteum, ... | 2005 | 16195938 |
| cloning and sequencing of the chromosomal dna and cdna encoding the mitochondrial citrate synthase of aspergillus niger wu-2223l. | the complementary dna (cdna) and chromosomal dna encoding the citrate synthase (ec 4.1.3.7) gene (cit1) of aspergillus niger wu-2223l, a citric acid-producing strain, were cloned. synthetic oligonucleotide primers were designed according to the amino acid sequences of already known eukaryotic citrate synthases and the codon bias of a. niger genes. the 920-bp dna fragment was amplified by polymerase chain reaction with these primers using chromosomal dna of wu-2223l as a template, and was employe ... | 1999 | 16232605 |
| cloning and expression of aspergillus niger icda gene encoding mitochondrial nadp+-specific isocitrate dehydrogenase. | the complementary dna (cdna) and chromosomal dna (icda) encoding the nadp+-specific isocitrate dehydrogenase (ec 1.1.1.42) of aspergillus niger wu-2223l, a citric acid-producing strain, were cloned. two cdna clones (cdna-1, 2.0 kb; cdna-2, 1.5 kb) were obtained and sequenced, and an orf of 1494 base pairs (bp) encoding a protein of 498 amino acids (aa) was identified in cdna-1. the predicted amino acid sequence showed 73% and 67% sequence identities with those of the mitochondrial nadp+-icdhs fr ... | 2002 | 16233178 |
| shifting the ph profile of aspergillus niger phya phytase to match the stomach ph enhances its effectiveness as an animal feed additive. | 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 o ... | 2006 | 16751556 |
| quantification of inositol phosphates using (31)p nuclear magnetic resonance spectroscopy in animal nutrition. | a (31)p nmr method for quantitative determination of inositol phosphates in simple incubation samples of sodium phytate and aspergillus niger phytase and in different types of complex samples, such as diets, digesta, and feces, is described. the inositol phosphates in complex samples were extracted with hcl, concentrated, and purified using freeze-drying and filtration and subsequently determined at ph 12.6 in aqueous solution using a (31)p nmr method. the (31)p nmr technique has as its main adv ... | 1999 | 10606582 |
| adopting selected hydrogen bonding and ionic interactions from aspergillus fumigatus phytase structure improves the thermostability of aspergillus niger phya phytase. | although it has been widely used as a feed supplement to reduce manure phosphorus pollution of swine and poultry, aspergillus niger phya phytase is unable to withstand heat inactivation during feed pelleting. crystal structure comparisons with its close homolog, the thermostable aspergillus fumigatus phytase (afp), suggest associations of thermostability with several key residues (e35, s42, r168, and r248) that form a hydrogen bond network in the e35-to-s42 region and ionic interactions between ... | 2007 | 17351092 |
| occurrence of ochratoxin a and ochratoxigenic mycoflora in corn and corn based foods and feeds in some south american countries. | cereals and cereal- derived products constitute the base of human and animal feeding in south american countries. this review attempts to give an overview of the ochratoxin a (ota) occurrence and potential sources of ota contamination in those products. the environmental conditions as humidity and temperature in the colonization of the substrates by aspergillus section nigri isolated from corn kernels were also discussed. the available information on the ochratoxigenic mycoflora and ota presence ... | 2007 | 17390233 |
| transgenic maize plants expressing a fungal phytase gene. | maize seeds are the major ingredient of commercial pig and poultry feed. phosphorus in maize seeds exists predominantly in the form of phytate. phytate phosphorus is not available to monogastric animals and phosphate supplementation is required for optimal animal growth. undigested phytate in animal manure is considered a major source of phosphorus pollution to the environment from agricultural production. microbial phytase produced by fermentation as a feed additive is widely used to manage the ... | 2008 | 17932782 |
| cumulative improvements of thermostability and ph-activity profile of aspergillus niger phya phytase by site-directed mutagenesis. | aspergillus niger phytase (phya) has been used as a feed supplement to reduce manure phosphorus excretion of swine and poultry but lacks sufficient thermostability for feed pelleting and appropriate ph-activity profile for phytate hydrolysis in the stomach of animals. previously, a thermostable mutant phya18 and two ph-activity profile-improved mutants e228k and k300e were developed. in this study, the mutations were combined to determine if both improvements were cumulative. four substitutions ... | 2008 | 17968540 |
| effect of body weight on phosphorus digestibility and efficacy of a microbial phytase in young pigs. | the effect of body weight on p digestibility and on efficacy of supplemental aspergillus niger phytase was studied in two experiments with young growing pigs. excreta were collected quantitatively. all diets contained 2.0 g digestible p per kg dry matter at a maximum and renal p excretion never exceeded 15 mg/d. when dietary p mainly originated from monocalcium-phosphate, both p digestibility and ca net absorption linearly increased by 3.6 and 5.6 percentage units, respectively, when bw increase ... | 1999 | 10548967 |
| effect of low doses of aspergillus niger phytase on growth performance, bone strength, and nutrient absorption and excretion by growing and finishing swine fed corn-soybean meal diets deficient in available phosphorus and calcium. | two experiments were conducted to evaluate the efficacy of low doses of aspergillus niger (an) phytase for growing and finishing pigs fed corn-soybean meal (sbm) diets with narrow ca:p ratios that were about 0.9 g/kg deficient in available p and ca. experiment 1 utilized 120 pigs with an early finisher period from 51.5 +/- 0.2 to 89.7 +/- 0.9 kg of bw and a late finisher period that ended at 122.5 +/- 2.0 kg of bw. during each period, treatments were the low-p diets with 0, 150, 300, or 450 unit ... | 2008 | 18156343 |
| chemoenzymatic synthesis of both enantiomers of 3-hydroxy-2,2-dimethylcyclohexanone. | the stereoselective acetylation of meso-2,2-dimethyl-1,3-cyclohexanediol by vinyl acetate in the presence of three lipases gave the (1r,3s)-monoester in high enantiomeric excess (ee > or = 98%). the hydrolysis of the corresponding meso-diacetate in the presence of candida antarctica lipase in phosphate buffer provided the opposite enantiomer. optically active monoacetates were converted to both enantiomers of 3-hydroxy-2,2-dimethylcyclohexanone, a versatile chiral building block. | 2008 | 18991382 |
| aspergillus niger absorbs copper and zinc from swine wastewater. | wastewater from swine confined-housing operations contains elevated levels of copper and zinc due to their abundance in feed. these metals may accumulate to phytotoxic levels in some agricultural soils of north carolina due to land application of treated swine effluent. we evaluated fungi for their ability to remove these metals from wastewater and found aspergillus niger best suited for this purpose. a. niger was able to grow on plates amended with copper at a level five times that inhibitory t ... | 2001 | 11211074 |
| hydrolysis of phytic acid by intrinsic plant or supplemented microbial phytase (aspergillus niger) in the stomach and small intestine of minipigs fitted with re-entrant cannulas. | hydrolysis of phytate in the stomach and the small intestine as influenced by intrinsic plant (wheat) and supplemented microbial phytase (a. niger) were investigated with six minipigs (40-50 kg initial bw) fitted with re-entrant-cannulas in the duodenum, 30 cm posterior to the pylorus (animals 1, 4, 5, and 6) and ileocecal re-entrant cannulas, 5 cm prior the ileocecal junction (animals 1, 2, and 3), respectively. dietary treatments were as follows: (1) diet 1, a corn-based diet (43 u phytase/kg ... | 2001 | 11906564 |
| hydrolysis of phytic acid by intrinsic plant and supplemented microbial phytase (aspergillus niger) in the stomach and small intestine of minipigs fitted with re-entrant cannulas. 2. phytase activity. | hydrolysis of phytate in the stomach and the small intestine as influenced by intrinsic plant (wheat) and supplemented microbial phytase (a. niger) were investigated with six minipigs (40-50 kg initial bw) fitted with re-entrant cannulas in the duodenum, 30 cm posterior to the pylorus (animals 1, 4, 5, and 6) and ileocecal re-entrant cannulas, 5 cm prior the ileocecal junction (animals 1, 2, and 3), respectively. dietary treatments were as follows: (1) diet 1, a corn-based diet (43 u phytase/kg ... | 2001 | 11906565 |
| 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 |
| modeling the fate of dietary phosphorus in the digestive tract of growing pigs. | environmental effects of the excess of p from manure and the soaring price of phosphates are major issues in pig production. to optimize p utilization, it is crucial to improve our capacity to predict the amount of p absorbed, while taking into account the main factors of variation. mathematical modeling can represent the complexity of the processes and interactions in determining the digestive utilization of phosphorus in growing pigs. this paper describes and evaluates a model developed to sim ... | 2011 | 21680789 |
| responses of pigs to aspergillus niger phytase supplementation of low-protein or high-phytin diets. | growth and n utilization responses of pigs to aspergillus niger phytase supplementation of low-protein or high-phytin diets were examined in 2 experiments. in the first experiment, 6 diets arranged in a 3 x 2 factorial with aspergillus niger phytase at 0, 600, or 1,200 units/kg and dietary protein at 160 or 200 g/kg; and 12 pigs (growth) or 6 pigs (n utilization) per diet were used to test the hypothesis that phytase ameliorates dietary protein effects on growth and nutrient balance. in the seco ... | 2009 | 19395519 |
| ochratoxin a in serum of swine from different brazilian states. | the aims of the current study were to monitor the presence of ochratoxin a (ota) in the serum of slaughtered swine and to investigate its distribution in 4 major geographical regions of brazil. a total of 400 samples of serum were collected from 4 major states of brazil (100 samples each). ochratoxin a concentrations were determined by high-performance liquid chromatography. in santa catarina state, 60% of the samples had ota concentrations ranging from 4.01 to 75.4 mg/l. in mato grosso state, 7 ... | 2010 | 20807935 |
| comparison of aspergillus niger phytase and trichoderma reesei phytase and acid phosphatase on phytate phosphorus availability in pigs fed on maize-soybean meal or barley-soybean meal diets. | the efficacy of aspergillus niger (aphy) phytase, trichoderma reesei (tphy) phytase and acid phosphatase (tacph) preparations in improving the utilization of phytin-phosphorus in the maize-soybean meal (sbm) or barley-sbm (800:200 g kg-1) diets was studied in two separate digestibility and balance trials with ten growing pigs using 5 x 5 latin square designs. the positive control diet contained a total phosphorus (p) of 6.5 g kg-1, while the negative control as well as the aphy, tphy and tacph s ... | 1999 | 10548973 |
| estimation of fungal growth using the ergosterol assay: a rapid tool in assessing the microbiological status of grains and feeds. | to use ergosterol assay as a rapid tool to assess the extent of fungal contamination in grains and feeds. | 2008 | 18086192 |
| protein buffering in model systems and in whole human saliva. | the aim of this study was to quantify the buffer attributes (value, power, range and optimum) of two model systems for whole human resting saliva, the purified proteins from whole human resting saliva and single proteins. two model systems, the first containing amyloglucosidase and lysozyme, and the second containing amyloglucosidase and alpha-amylase, were shown to provide, in combination with hydrogencarbonate and di-hydrogenphosphate, almost identical buffer attributes as whole human resting ... | 2007 | 17327922 |