Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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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)

Twenty-four Hansenula polymorpha transformants were passaged and stabilised in glucose medium and screened in glycerol medium for recombinant phytase in shaken test tubes. The cultivations were performed under either limited or non-limited oxygen supply. Maximum oxygen transfer capacities of test tubes were assessed by sulfite oxidation. Oxygen-limited glucose cultures resulted in a partially anaerobic metabolism and formation of 4.1 g ethanol l(-1), which was subsequently aerobically metabolised. Non-limited oxygen supply led to overflow metabolism and to accumulation of 2.1 g acetic acid l(-1), reducing the biomass yield. The use of glycerol in the screening main cultures prevented by-product formation irrespective of oxygen supply. Preculturing in glucose medium under non-limited oxygen supply resulted in a 20-h lag phase of the screening main culture. This lag phase was not observed when preculturing was performed under oxygen limitation. Phytase activity was on average 25% higher in cultures passaged, stabilised and screened under limited oxygen supply than in cultures under non-limited oxygen supply.
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PMID:Effect of oxygen supply on passaging, stabilising and screening of recombinant Hansenula polymorpha production strains in test tube cultures. 1461 84

Two experiments were conducted to determine the effect of phytase on plasma metabolites and AA and energy digestibility in swine. In Exp. 1, eight barrows (surgery BW = 52 kg) were fitted with steered ileocecal cannulas. The experiment was a Latin rectangle and the treatments were 1) corn-soybean meal diet adequate in Ca and P (0.5% Ca, 0.19% available P [aP]), 2) corn-soybean meal diet with reduced Ca and P (0.4% Ca, 0.09% aP), 3) Diet 1 with 500 phytase units/kg, or 4) Diet 2 with 500 phytase units/kg. Pigs were fed twice daily to a total daily energy intake of 2.6 x maintenance (106 kcal of ME/kg of BW(0.75)). For each ileal digesta sample, digesta samples were collected for two 24-h periods and combined for each pig. The combination of supplementing with phytase and decreasing the concentration of dietary Ca and P increased average ileal AA (P < 0.02), starch (P < 0.02), GE (P < 0.04), and DM (P < 0.03) digestibilities. In Exp. 2, a feeding challenge was conducted with barrows (eight per treatment; average BW of 53 kg). The treatments consisted of a corn-soybean meal diet or corn-soybean meal diet + 500 phytase units per kilogram of diet. In the diet with no phytase, Ca and aP were at 0.50% and 0.19%, respectively, and, in the diet with phytase, Ca and aP were each decreased by 0.12%. A catheter was surgically inserted into the anterior vena cava of each pig 6 d before the start of the feeding challenge. The barrows were penned individually, and the diets were fed for 3 d before the challenge. The pigs were held without feed for 16 h, and blood samples were obtained at -60, -30, and 0 min before the pigs were fed (2% of BW). Blood samples were then collected at 10, 20, 30, 40, 50, 60, 75, 90, 105, 120, 150, 180, 210, 240, 270, and 300 min after feeding. Glucose area under the response curve and plasma glucose, insulin, urea N, and total alpha-amino N concentrations were increased (P < 0.05) in pigs fed the diet with reduced Ca and P and the phytase addition. Area under the response curve for insulin, urea N, and total alpha-amino N; insulin:glucose; and plasma NEFA concentration, clearance, and half-life were not affected by diet. In conclusion, the combination of Ca and P reduction and phytase addition increased nutrient and energy digestibility in diets for pigs and increased plasma concentrations of glucose, insulin, urea N, and alpha-amino N.
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PMID:Effect of phytase addition and dietary calcium and phosphorus levels on plasma metabolites and ileal and total-tract nutrient digestibility in pigs. 1503 27

1. The effects of myo-inositol hexaphosphate (IP6) and phytase (EC 3.1.3.26) on the excretion of endogenous compounds were investigated using growing broiler chickens. 2. A total of 32 female Ross broilers were used in a precision feeding assay involving a 2 x 2 factorial arrangement of treatments. The materials administered were glucose, glucose + 1000 units of phytase activity (FTU), glucose + 1 g of IP6 and glucose + 1 g of IP6 + 1000 FTU. Excreta were collected quantitatively over a 48-h period following intubation of the test materials. The excretion of nitrogen, amino acids, minerals, sialic acid and phytate phosphorus was determined. 3. The ingestion of 1 g of IP6 by broilers increased the excretion of endogenous nitrogen, amino acids, iron, sodium, sulphur and sialic acid compared with birds fed on glucose. Supplementation of IP6 with exogenous phytase reduced the excretion of endogenous amino acids, calcium, sodium, phytate phosphorus and sialic acid compared with birds fed IP6. 4. It can be concluded that IP6 increases the excretion of endogenous minerals and amino acids in broiler chickens. Part of the beneficial effects of the addition of exogenous phytases to the diets of poultry appears to be mediated through a reduction in endogenous losses of these nutrients.
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PMID:The effects of phytase and phytic acid on the loss of endogenous amino acids and minerals from broiler chickens. 1511 7

Phytases act on phytic acid, an antinutrient factor present in animal feeds, and release inorganic phosphate. We optimized the production parameters for phytase production using Thermoascus aurantiacus (TUB F 43), a thermophilic fungal culture, by submerged fermentation. A semisynthetic medium containing glucose, starch, peptone, and minerals supplemented with 3.75% (w/v) wheat bran particles was found to be the best production medium among the various combinations tried. Further supplementation of this medium with surfactants such as Tween-20 and Tween-80 considerably enhanced the enzyme yield. A maximum phytase activity (468.22 U/mL) was obtained using this production medium containing 2% (v/v) Tween-20 after 72 h of fermentation at 45 degrees C in shake-flask cultures with a rotation of 150 rpm. Herein we present details of a few of the process parameter optimizations. The phytase enzyme was found to be thermostable, and the optimal temperature for phytase activity was found to be 55 degrees C. However, 80% of the activity still remained when the temperature was shifted to 70 degrees C.
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PMID:Thermostable phytase production by Thermoascus aurantiacus in submerged fermentation. 1530 50

An experiment was conducted to determine the effects of phytase addition, reduced Ca and available P (aP), and removing the trace mineral premix (TMP) on growth performance, plasma metabolites, carcass traits, pork quality, and tissue mineral content in growing-finishing swine. One hundred twenty cross-bred pigs (initial and final BW of 22 and 109 kg, respectively) were allotted to five dietary treatments on the basis of weight within gender in a randomized complete block design. There were three replications of barrows and three replications of gilts, with four pigs per replicate pen. The dietary treatments were as follows: 1) corn-soybean meal (C-SBM), 2) C-SBM with reduced Ca and aP, 3) C-SBM with reduced Ca and aP plus 500 phytase units/kg of diet, 4) Diet 1 without the TMP, and 5) Diet 3 without the TMP. The Ca and aP were reduced by 0.10% in the low Ca and aP diets and the diets with added phytase. Daily gain, hot carcass weight, dressing percent, kilograms of carcass lean, bone ash percent, and bone strength were decreased (P = 0.10), but liver and kidney weight were increased (P = 0.10) in pigs fed diets with reduced Ca and aP; adding phytase reversed these responses (P = 0.10). The Commission Internationale de I'Eclairage L* was decreased (P = 0.09) in pigs fed the low Ca and aP diet plus phytase relative to those fed the control diet. Removing the TMP had no effect on overall growth performance, but it increased (P = 0.03) 10th-rib backfat thickness and fasting glucose and decreased (P = 0.03) carcass length and ham weight. Liver weight and liver weight as a percentage of final BW were not affected when phytase was added to the control diet, but removing the TMP increased liver weight and liver weight as a percentage of final BW; adding phytase reversed these responses (phytase x TMP, P = 0.06). Removing the TMP decreased (P = 0.08) Zn concentrations in the bone, muscle, and liver, and Cu and Fe concentrations in the bile but increased (P = 0.08) Mn concentrations in the bile and liver of pigs. The addition of phytase reversed the negative effects of the reduced Ca and aP diets. These data indicate that removing the TMP in diets for growing-finishing pigs has no negative effects on growth performance or pork quality, but it had negative effects on carcass traits and had variable effects on tissue mineral content.
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PMID:Effects of microbial phytase, low calcium and phosphorus, and removing the dietary trace mineral premix on carcass traits, pork quality, plasma metabolites, and tissue mineral content in growing-finishing pigs. 1544 80

Using a screening procedure developed for detection of phytate hydrolysing enzymes, the gene agpE encoding glucose-1-phosphatase was cloned from an Enterobacter cloacae VKPM B2254 plasmid library. Sequence analysis revealed 78% identity on nucleotide and 79% identity on peptide level to Escherichia coli glucose-1-phosphatase characterising the respective gene product as a representative of acid histidine phosphatases harbouring the RH(G/N)RXRP motif. The purified recombinant protein displayed maximum specific activity of 196 U mg(-1) protein against glucose-1-phosphate but was also active against other sugar phosphates and p-nitrophenyl phosphate. High-performance ion chromatography of hydrolysis products revealed that AgpE can act as a 3-phytase but is only able to cleave off the third phosphate group from the myo-inositol sugar ring. Based on sequence comparison and catalytic behaviour against phytate, we propose to classify bacterial acid histidine phosphatases/phytases in the three following subclasses: (1) AppA-related phytases, (2) PhyK-related phytases and (3) Agp-related phytases. A distinguished activity of 32 U mg(-1) of protein towards myo-inositol-hexa-phosphate, which is two times higher than that of E. coli Agp, suggests that possibly functional differences in terms of phytase activity between Agp- and AppA-like acid histidine phosphatases are fluent.
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PMID:Glucose-1-phosphatase (AgpE) from Enterobacter cloacae displays enhanced phytase activity. 1619 76

In our previous study, it was determined that phytase produced by Aspergillus oryzae plays an important role in supplying phosphate to yeast in the process of making sake. During koji making, two types of phytase (Phy-I and Phy-II) are produced. The purified phytases have high thermal and pH stability, in comparison to phytase purified from a submerged culture (ACP-II). In the present study, Phy-I and Phy-II retained their activities for 45 h. The NH2-terminal sequence of Phy-1, which is eight amino acids in length, was identical to that of ACP-II, but the molecular weights of these two forms, as estimated by SDS-PAGE, were quite different from each other (Phy-I, 120 kDa; ACP-II, 58 kDa). From the NH2-terminal amino acid sequence analysis of the predominant phytase (Phy-II), a molecular weight of 116 kDa was expected to reflect a new type of phytase produced only in koji culture. The substrate specificity of Phy-II was sufficiently broad that it hydrolyzed not only phytic acid and p-nitro phenyl phosphate, but also glucose 6-phosphate and glycerol 1-phosphate. In the process of making koji, Phy-I was produced at an early stage, followed by Phy-II; with both phytases being thought to function to hydrolyze phytic acid cooperatively.
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PMID:Production of two types of phytase from Aspergillus oryzae during industrial koji making. 1623 40

Phytase (myo-inositol-1,2,3,4,5,6-hexakisphosphate phosphohydrolase, EC 3.1.3.26) catalyses the stepwise hydrolysis of phytic acid (myo-inositol hexakisphosphate). Phytases are of great commercial importance due to their usage as supplement of food and animal feed, which can cater to nutrition demands and alleviate environmental problems, has been approved by many countries. Although acid phytases have been extensively studied, information regarding the phytases from Citrobacter is limited. In the work presented, a phytase was separated from Citrobacter freundii. After steps of electrophoretic homogeneity by successive ammonium sulfate between 60% and 80% saturation precipitation, DEAE-Sepharose ion-exchange chromatography and gel filtration through Superdex HR 10/30, final gel elution resulted in a 41.3-fold purification and yield of 9.3%. Gel elution is an effective method to purify the protein which contaminated with a few other proteins. The purified preparations were used in subsequent characterization studies. Based on SDS-PAGE analysis, the molecular weight of the purified phytase was calculated to be approximately 45.0kDa in monomeric form. The pure enzyme has an optimum pH of 4.0 to approximately 4.5. It was found stable between pH5.0 to approximately 7.0, about 90% of the enzyme activity was retained at 37 degrees C for 60min. The phytase has an optimum temperature of 40 degrees C which was lower than that of other phytases from Aspergillus or E. coli (average 50 to approximately 60 degrees C) and was close to the temperature of gastrointestinal tract in animals (37 to approximately 40 degrees C). Thus the enzyme is a promising candidate for animal feed applications. Activity of the purified phytase was influenced by changing the reaction temperature. Data showed that the enzyme retained its activity over a long period when stored at 4 degrees C, whereas thermal inactivation studies indicated that the enzyme lost 100% activity after treatment at 60 degrees C for 4min. The Km values of the phytase for dodecasodium phytate at 37 degrees C was 0.85nmol/L with a Vmax 0.53IU/(mg x min). Phytase activity was strongly inhibited by SDS, Zn2+ and moderately inhibited by Cu2+, Cr3+, Fe2+ and Fe3+. Activity was not significantly affected by EDTA, K+, Mg2+ and Ca2+. The phytase has excellent resistance to trypsin, but not pepsin. The N-terminal amino acids sequence of the phytase protein was determined as QCAPEGYQLQQVLMM which exhibited about 80% homology to Glucose-1-phosphatases from E. coli, Shigella flexneri and Salmonella, whereas it did not show apparent sequence similarity with any other phytase listed in the databases. Initial characterization of the purified enzyme suggested that it is a potential candidate for use as an animal feed supplement.
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PMID:[Purification and properties of Citrobacter freundii phytase]. 1657 82

The effect of the ingestion of myo-inositol hexaphosphate (IP6) and phytase (EC 3.1.3.26) on the digestibility of casein was investigated using growing broiler chickens. A total of 64 female Ross broilers were used in a precision feeding study. One group of 8 birds was fed a solution of glucose to estimate endogenous losses. Seven groups, each of 8 birds, were fed either casein, casein + 1,000 units of phytase activity (FTU), casein + 2,000 FTU, casein + 0.5 g of IP6, casein + 0.5 g of IP6 + 1,000 FTU, casein + 1 g of IP6, or casein + 1 g of IP6 + 1,000 FTU. The excretion of DM, amino acids, nitrogen, minerals, and phytate-phosphorus was determined over a 48-h period and nutrient digestibility coefficients were calculated. Casein was found to be highly digestible, with true coefficients of DM, N, and amino acid digestibility of between 0.85 and 1.0. However, the ingestion of IP6 reduced (P < 0.05) the digestibility coefficients of amino acids, N, and DM of casein compared with birds fed casein alone. Supplementation of the mixture of casein and IP6 with phytase improved (P < 0.05) the digestibility coefficients of amino acids compared with birds fed on casein and IP6 with no supplemental phytase. The excretion of endogenous minerals was increased (P < 0.05) by the ingestion of IP6 and reduced (P < 0.05) by the supplementation of IP6 with phytase. In the absence of exogenous phytase, the recovery of phytate-P in excreta was approximately 80%. However, the recovery of phytate-P was significantly reduced by the addition of exogenous phytase to the IP6/casein mixture. It can be concluded that the ingestion of IP6 reduces the digestibility coefficients of amino acids and the metabolizability of nitrogen of casein. This is likely to be mediated partially through increased endogenous losses. However, the addition of phytase can partially ameliorate the detrimental effects of IP6 on protein utilization.
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PMID:Phytic acid and phytase: implications for protein utilization by poultry. 1667 66

The phytase production by Sporotrichum thermophile TLR50 was recorded on all the commonly used animal feed ingredients tested to varying degrees in solid-state fermentation. Enzyme production increased to 180 U/g of dry moldy residue (DMR) in sesame oil cake at 120 h and 45 degrees C at the initial substrate-to-moisture ratio of 1:2.5 and aw of 0.95. Supplementation of sesame oil cake with glucose and ammonium sulfate further enhanced phytase titer (282 U/g of DMR). An overall 76% enhancement in phytase production was achieved owing to optimization. The mold secreted acid phosphatase, amylase, xylanase, and lipase along with phytase. By the action of phytase, inorganic phosphate was liberated efficiently, leading to dephytinization of sesame oil cake.
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PMID:Phytase production by thermophilic mold Sporotrichum thermophile in solid-state fermentation and its application in dephytinization of sesame oil cake. 1672 Sep 4


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