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Query: EC:3.1.3.8 (phytase)
 1,997 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Phytate is the major form of organic phosphorus in soil. Elevating the phyrase activity in transgenic plants may be an effective approach to promote their phytate-phosphorus utilization, but little is known about the applied conditions. In this study, several transgenic tobacco lines carrying Bacillus subtilis phytase gene were compared with wild-type tobacco, in terms of their ability in acquiring phosphorus from phytate in sterilized agar, sand and soil. In sterilized agar, transgenic tobacco plants were more efficient in phytate-phosphorus uptake and utilization, and their biomass and total phosphorus content were 3.6-10.7 and 2.2-4.6 fold of the wild-type's, respectively. In sand and soil systems, however, there were no significant differences in biomass and total phosphorus content between the trsansgenic and wild-type tobacco plants. These results indicated that Bacillus phytase transgene could only improve the phytate-phosphorus uptake by transgenic plants under sterilized condition, and its effectiveness might be limited under natural conditions because of microbial decomposition and mineral fixation. Therefore, further research is needed to understand the limiting factors on the functions of the transgene.
Ying Yong Sheng Tai Xue Bao 2005 Dec
PMID:[Phytate-phosphorus uptake and utilization by transgenic tobacco carrying Bacillus subtilis phytase gene]. 1651 94

A Yersinia intermedia strain producing phytase was isolated from glacier soil. The phytase gene, appA, was isolated by degenerate PCR and TAIL-PCR. The full-length fragment contained 2354bp with a 1326-bp open reading frame encoding 441 amino acids. APPA contained the active site RHGXRXP and HD sequence motifs that are typical of histidine acid phosphatases. To our knowledge, this is the first report of the detection of phytase activity and cloning of the relevant gene from Y. intermedia. The gene was overexpressed in Pichia pastoris, and the purified recombinant APPA had a specific activity for sodium phytate of 3960U/mg, which is higher than that of the Citrobacter braakii phytase (previously the highest specific activity known). Recombinant APPA had high activity from pH 2 to 6 (optimum 4.5) and optimal temperature of 55 degrees C; the enzyme was resistant to pepsin and trypsin. These characteristics suggest that APPA may be highly suitable for use in the feed industry.
Biochem Biophys Res Commun 2006 Dec 01
PMID:A novel phytase with preferable characteristics from Yersinia intermedia. 1703 58

Two studies were conducted to determine the efficacy of an Escherichia coli-derived phytase (ECP) and its equivalency relative to inorganic phosphorus (iP) from monosodium phosphate (MSP). In Exp. 1, one thousand two hundred 1-d-old male broilers were used in a 42-d trial to assess the effect of ECP and iP supplementation on growth performance and nutrient digestibility. Dietary treatments were based on corn-soybean meal basal diets (BD) containing 239 and 221 g of CP, 8.2 and 6.6 g of Ca, and 2.4 and 1.5 g of nonphytate P (nPP) per kg for the starter and grower phases, respectively. Treatments consisted of the BD; the BD + 0.6, 1.2, or 1.8 g of iP from MSP per kg; and the BD + 250, 500, 750, or 1,000 phytase units (FTU) of ECP per kg. Increasing levels of MSP improved gain, gain:feed, and tibia ash (linear, P < 0.01). Increasing levels of ECP improved gain, gain:feed, tibia ash (linear, P < 0.01), apparent ileal digestibility of P, N, Arg, His, Phe, and Trp at d 21 (linear, P < 0.05), and apparent retention of P at d 21 (linear, P < 0.05). Increasing levels of ECP decreased apparent retention of energy (linear, P < 0.01). Five hundred FTU of ECP per kg was determined to be equivalent to the addition of 0.72, 0.78, and 1.19 g of iP from MSP per kg in broiler diets based on gain, feed intake, and bone ash, respectively. In Exp. 2, forty-eight 10-kg pigs were used in a 28-d trial to assess the effect of ECP and iP supplementation on growth performance and nutrient digestibility. Dietary treatments consisted of a positive control containing 6.1 and 3.5 g of Ca and nPP, respectively, per kg; a negative control (NC) containing 4.8 and 1.7 g of Ca and nPP, respectively, per kg; the NC diet plus 0.4, 0.8, or 1.2 g of iP from MSP per kg; and the NC diet plus 500, 750, or 1,000 FTU of ECP per kg. Daily gain improved (linear, P < 0.05) with ECP addition, as did apparent digestibility of Ca and P (linear, P < 0.01). Five hundred FTU of ECP per kg was determined to be equivalent to the addition of 0.49 and 1.00 g of iP from MSP per kg in starter pigs diets, based on ADG and bone ash, respectively.
J Anim Sci 2006 Dec
PMID:Efficacy and equivalency of an Escherichia coli-derived phytase for replacing inorganic phosphorus in the diets of broiler chickens and young pigs. 1709 29

Iron deficiency represents one of the most common global nutritional disorders in humans. Our objective was to determine whether and how supplemental inulin improved utilization of iron intrinsically present in a corn and soybean meal diet by young pigs for hemoglobin repletion. In Expt. 1, 3 groups (n = 8/group) of pigs were fed a corn and soybean meal-based diet (BD, without inorganic iron addition) or BD + 2 or 4% inulin (Synergy 1: a mixture of oligofructose and long-chain inulin HP, Orafti) for 5 wk. Final blood hemoglobin concentrations and the overall hemoglobin repletion efficiency of pigs were positively (r = 0.55 and 0.69, P < 0.01) correlated with dietary inulin concentrations. Compared with pigs fed the BD, those fed 4% inulin demonstrated a 28% improvement (P < 0.01) in hemoglobin repletion efficiency and 15% (P < 0.01) improvement in the final blood hemoglobin concentration. In Expt. 2, 12 weanling pigs (n = 6/group) were fed the BD or the BD + 4% inulin for 6 wk. Pigs fed 4% inulin had higher (P < 0.05) soluble Fe concentrations in the digesta of the proximal, mid, and distal colon, and lower (P < 0.05) sulfide concentrations in the digesta of the distal colon. Supplemental inulin had virtually no effect on pH or phytase activity of digesta from any of the tested segments. In conclusion, supplementing 4% inulin improved utilization of intrinsic iron in the corn and soybean meal diet by young pigs, and this benefit was associated with soluble Fe and sulfide concentrations but not pH or phytase activity in the digesta.
J Nutr 2006 Dec
PMID:Supplemental dietary inulin affects the bioavailability of iron in corn and soybean meal to young pigs. 1711 16

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 ectoine led to an increase in the relative hydrolytic rate of sodium phytate by 15.7% with heating at 80 degrees C for 15 min. Among the compatible solutes examined, ectoine was confirmed to be the most efficient thermoprotectant for PHYA II.
J Biosci Bioeng 2006 Dec
PMID:Supplementation effect of ectoine on thermostability of phytase. 1727 Jul 22

Aspergillus oryzae RIB40 niaD(-) was transformed using a plasmid constructed with the A. oryzae phytase gene and pNAN8142 vector. The culture broth of the transformant, which was grown in a medium containing starch as a carbon source and polyvinylpyrrolidone showed phytase activity of a maximum of 2.0 units ml(-1) at 37 degrees C, pH 5.5.
J Biosci Bioeng 2006 Dec
PMID:Expression of Aspergillus oryzae phytase gene in Aspergillus oryzae RIB40 niaD(-). 1727 Jul 23

Utilization of the phytase with high specific activity is an effective way to improve the fermentation potency of phytase in recombinant host and decrease the production cost. Up to now, the phytase APPA from Citrobacter braakii exhibits the highest specific activity in the all phytases recorded previously. The gene AppA encoding phytase was modified according to the bias in codon choice of the high expression gene in Pichia pastoris without changing the amino acid sequence and artificially synthesized. The modified gene, AppA ( m) , was inserted into the Pichia pastoris expression vector pPIC9 under the control of AOX1 promoter, and the resulted expression vector pPIC9-AppA ( m) was introduced into the host Pichia pastoris by electroporation. PCR analysis of the recombinant yeast indicated that AppA (m) gene was integrated into the chromosome of Pichia pastoris. The Pichia pastoris recombinants for phytase overexpression were screened by enzyme activity analysis and SDS-PAGE. The recombinant phytase APPA was purified by simple methods, such as dialysis, ultrafiltration and chromatography. After the simple purification, the purity of the recombinant phytase reached to electrophoresis purity, and the recombinant phytase was shown to be glycosylated by Endo-H treatment. The specific activity of the purified recombinant APPA was 3.5 x 10(6) IU/mg of protein. Recombinant phytase APPA showed activity at pH values from 2.0 through 7.0 with the optimum at 4.5. The temperature optimum was 55 degrees C at pH 4.5.The Km value for sodium phytate was 0.165mmol/L with a Vmax of 3.3 x 10(6)IU/mg min. In 5-liter fermentor in fed-batch fermentation, the expression level of phytase in recombinant Pichia pastoris was 3.2mg/mL and the fermentation potency exceeded 1.4 x 10(7) IU/mL, which is the highest level among all of the reported phytase recombinant strains at present.
Wei Sheng Wu Xue Bao 2006 Dec
PMID:[Overexpression of Citrobacter braakii phytase with high specific activity in Pichia pastoris]. 1730 59

Using a combination of High-Performance Ion Chromatography analysis and kinetic studies, the pathway of myo-inositol hexakisphosphate dephosphorylation by a phytase from a Malaysian waste-water bacterium was established. The data demonstrate that the phytase preferably dephosphorylates myo-inositol hexakisphosphate in a stereospecific way by sequential removal of phosphate groups via D-I(1,2,3,4,5)P(5), D-I(2,3,4,5)P(4), D-I(2,3,4)P(3), D-I(2,3)P(2) to finally I(2)P. It was estimated that more than 90% of phytate hydrolysis occurs via D-I(1,2,3,4,5)P(5). Thus, the phytase from the Malaysian waste-water bacterium has to be considered a 6-phytase (E.C. 3.1.3.26). A second pathway of minor importance could be proposed which is in accordance with the results obtained from analysis of the dephosphorylation products formed by the action of the phytase under investigation on myo-inositol hexakisphosphate. It proceeds via D/L-I(1,2,4,5,6)P(5), D/L-I(1,2,4,5)P(4), D/L-I(1,2,4)P(3), D/L-I(2,4)P(2) to finally I(2)P.
Protein J 2007 Dec
PMID:myo-inositol phosphate isomers generated by the action of a phytase from a malaysian waste-water bacterium. 1780 50

1. A total of 30 varieties and selection lines of triticale grown under similar conditions were characterised. Thousand grain weight, specific weight, Hagberg falling number and N were 50.2 +/- 5.0 g, 72.4 +/- 2.1 kg/hl, 96 +/- 48 s and 16.1 +/- 0.11 g/kg, respectively. 2. Mean phosphorus (P) concentration was 2.86 +/- 0.31 g/kg, of which 77% was of phytic origin. Mean phytase activity was 1018 +/- 319 phytase units (PU)/kg. A genotypic effect on phytase activity was detected amongst 5 varieties studied out of 30. Potential and real applied viscosities were positively correlated and mean values were 3.53 +/- 0.66 and 2.15 +/- 0.31 ml/g, respectively. 3. The efficacy of plant phytase in improving P availability was assessed in chickens up to 3 weeks of age. Growth performance and bone ash concentration were compared in birds given either a maize (450 g/kg) and soybean meal (230 g/kg) phosphorus deficient diet containing 3.5 g P/kg, this basal diet supplemented with 1 or 2 g P/kg as monocalcium phosphate (MCP) or triticale (450 g/kg) and soybean meal (230 g/kg) diets containing 3.2 to 3.8 g P/kg with no MCP. To achieve graded levels of phytase activity, 4 varieties of triticale, intact or in which phytase was denaturated by heat treatment, were used. Estimated metabolisable energy, protein, amino acids and calcium concentrations were similar in all diets. 4. Phytase activity in the triticale-based diets ranged between 135 and 1390 PU/kg. Growth performance and bone ash were responsive to plant phytase and to MCP. Non-linear models of these responses were adjusted with the best fit for bone ash parameters. The values of 250, 500 and 1000 PU of plant phytase were estimated to be equivalent to 0.46, 0.67 and 0.81 g P as MCP, respectively.
Br Poult Sci 2007 Dec
PMID:Characterisation of European varieties of triticale with special emphasis on the ability of plant phytase to improve phytate phosphorus availability to chickens. 1808 50

1. The purpose of this study was to investigate the effects of Bioplex Zn (a chelated zinc proteinate) and phytase supplementation in a maize-soybean meal diet on the performance and tissue zinc (Zn) content of broiler chicks. Treatment structure consisted of a 2 x 6 factorial arrangement with two inclusions of phytase (0 or 500 PU/kg) and 6 of Bioplex Zn providing 0, 2, 4, 8, 16 and 32 mg Zn/kg diet. A total of 864 chicks were randomly assigned to each of 12 dietary treatments with 6 replicate cages of 12 chicks. 2. Dietary inclusion of phytase increased feed intake, weight gain, plasma Zn content, tibia Zn content, tibia and ash weight. 3. Dietary supplementation of Bioplex Zn linearly increased feed intake, weight gain, gain to feed ratio, plasma Zn concentration, liver Zn concentration, tibia Zn content, tibia and ash weight. 4. An interactive effect of phytase and Bioplex Zn on feed intake, weight gain, tibia Zn concentration and tibia ash weight was found. 5. One slope, straight broken-line analysis of weight gain regressed on the supplemental Zn level provided as Bioplex Zn indicated that 12 mg/kg supplemental Zn without phytase and 7.4 mg/kg supplemental Zn with phytase were required for the optimal weight gain of chicks.
Br Poult Sci 2007 Dec
PMID:Effects of organic zinc and phytase supplementation in a maize-soybean meal diet on the performance and tissue zinc content of broiler chicks. 1808 51


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