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)

1. The effect of extrusion cooking of a high-fibre cereal product on digestibility of starch, fibre components and phytate in the stomach and small intestine was studied by in vivo digestion in ileostomy subjects, as well as its effect on ileostomy losses of fat, nitrogen, sodium and potassium. 2. Seven ileostomy subjects were studied during two periods (each of 4 d) while on a constant low-fibre diet supplemented with 54 g/d of a bran-gluten-starch mixture (period A) or the corresponding extruded product (period B). 3. Extrusion cooking, using mild conditions, did not change the content of starch, dietary fibre components or phytate of the bran product, but the phytase (EC 3.1.3.26) activity was lost. During the period using the extruded bran product, there was a significant increase in recovery of phytate-phosphorus (period A, 44% of intake; period B, 73% of intake). The amount of fibre components, fat, fatty acids, N, Na, K, water and the ash weight of the ileostomy contents did not differ between the two periods. Only 0.6 and 0.7% respectively of ingested starch was recovered in ileostomy contents in periods A and B, while the fibre components were almost completely recovered. 4. Extrusion cooking, using even mild conditions, may lead to a considerable impairment in the digestion of phytate, probably due to a qualitative change in phytate and a loss of phytase activity. Starch, before and after extrusion cooking, is almost completely digested in the stomach and small intestine while fibre components are digested to a very small extent.
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PMID:Extrusion cooking of a high-fibre cereal product. 1. Effects on digestibility and absorption of protein, fat, starch, dietary fibre and phytate in the small intestine. 282 63

Phytic acid in food is considered to be responsible for a reduced bioavailability of essential dietary minerals; its detrimental effects can be diminished by hydrolysis with phytase during processing. The average phytic acid content was 8.18 mg/g and 3.44 mg/g and average phytase activity was 3.7 U/g and 2.6 U/g in rye kernels and in flour (Type 997, 1.09 ash content), respectively. Phytate and Phytase were about equally distributed between the two kernel halves (cross sections). During the early stages of germination (3 days) phytase activity did not change, and phytic acid content was reduced to 67%. After milling most of the phytic acid and phytase activity were found in the bran fractions. It is concluded that substrate and enzyme are present in the same kernel structures but separate within the cells. Cooking of ground rye caused a phytate hydrolysis which was the more effective 1.) the smaller the particle sizes were, 2.) the more water was added, and 3.) the longer phytase worked at optimum temperature. Extrusion cooking of the rye whole flour at up to 100 degrees C did not influence the phytic acid level but caused a 23% reduction at 170 degrees C. Phytase activity was reduced by 80% by extrusion cooking at 80 degrees C.
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PMID:[Phytic acid and cereals and cereal products. I: Phytic acid and phytase in rye and rye products]. 301 3

The cause of marked inhibitory effect of bran on absorption of dietary nonheme iron was studied in man by double-radioiron technique. Washing bran with hydrochloric acid but not with water removed inhibitory factor(s). Inhibition was almost restored by reconstituting phytate level. Removal of phytates in bran by endogenous phytase significantly increased absorption of iron. Removing, by washing with water, phosphates formed from phytates during enzymatic dephytinization led to a bran fraction with only a small remaining inhibitory effect on iron absorption. Half the iron in bran is in the form of monoferric phytate, which is well-absorbed. When potassium and magnesium phytates were added in amounts present in bran, the same inhibitory effect on iron absorption was seen. Although there appear to be other factors in bran that partly explain the inhibition, phytates are the main cause of the inhibitory effect of bran on iron absorption.
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PMID:Phytates and the inhibitory effect of bran on iron absorption in man. 303 44

Low-phytate wheat bran was produced by enzymatic hydrolysis and extraction. Rat bioassay methods were utilized to determine bioavailability of iron and zinc in the low-phytate brans and to study the effect of dietary phytate/zinc molar ratio on zinc bioavailability when the phytate source was bran. Endogenous phytase activity hydrolyzed 80-100% of the phytate when wheat bran was incubated in water overnight. The relative biological values of the iron in raw bran and phytate-free bran were 98 and 113, respectively, compared to 100 for ferrous ammonium sulfate in a hemoglobin repletion assay. Low-phytate brans with phytate/zinc molar ratios of 8 or less were equivalent to zinc sulfate as dietary sources of zinc for growth of rats. Rats fed diets that contained wheat bran with zinc sulfate added to reduce the dietary phytate/zinc molar ratio from 40 or 50 to 20 grew at the same rate as rats fed a phytate-free diet, but femur zinc values were lower than those in the reference group. Gel filtration chromatography of extracts of raw and low-phytate brans suggested that zinc might be associated with phytate in wheat bran.
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PMID:Bioavailability to rats of iron and zinc in wheat bran: response to low-phytate bran and effect of the phytate/zinc molar ratio. 625 2

An in vitro method was developed to predict inorganic P release from maize-soyabean poultry feeds containing supplemental phytase (EC 3.1.3.8), and to quantify the effect of acid phosphatase (EC 3.1.3.2), fungal protease (EC 3.4.23.6) and Aspergillus niger cellulase (EC 3.2.1.4) on phytate dephosphorylation. Pepsin (EC 3.4.23.1) and pancreatin digestion periods were preceded by a 30 min pre-incubation at pH 5.25 to simulate digestion in the crop of poultry. Pancreatin digestion was carried out in dialysis tubing, with a ratio of about 1:25 (v/v) between the digesta and dialysing medium, to simulate gradient absorption from the duodenum. The feed:water ratio was kept within physiological limits and a constant proportion of feed weight to digestive enzymes was maintained. There was a linear response to increasing dosages of phytase up to 1000 phytase units (FTU)/kg feed, and to increasing phosphate concentration in feeds. In vivo validation was performed with growing turkeys (1-3 weeks) fed on diets containing 12 g Ca/kg and 0, 500 or 1000 FTU phytase/kg in a factorial arrangement with 0, 1, 2 or 3 g supplemental phosphate/kg (from KH2PO4). After a simple transformation (variable/in vitro P = f (in vitro P)), amounts of P hydrolysed from feed samples by in vitro digestions correlated with 3-week body-weight gain (R 0.986, P < 0.0001), toe ash (R 0.952, P < 0.0001), feed intake (R 0.994, P < 0.0001) and feed efficiency (R 0.992, P < 0.0001). The dephosphorylating ability of phytase in vitro was significantly enhanced (P < 0.05) by the addition of acid phosphatase. Fungal acid protease and Aspergillus niger cellulase also enhanced the dephosphorylation process in vitro.
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PMID:An in vitro procedure for studying enzymic dephosphorylation of phytate in maize-soyabean feeds for turkey poults. 754 27

Effects of a supplemental Aspergillus niger-phytase on digestibility and utilization of dietary phosphorus (P) were studied in three experiments with rainbow trout. P concentration in the diets was 4.8 and 5.8 g/kg DM, respectively. The P contained in the diet originated solely from plants, mainly soy-products. Digestibility of P was studied using the stripping method and hydrochloride insoluble ash as marker. Utilization was studied in growth trials by use of the comparative body analysis. At a water temperature of 15 degrees C, both digestibility and utilization of P were increased from 25 to 57% and from 17 to 49%, respectively when 1000 U/kg phytase were supplemented. Feed consumption and gain of trout were significantly increased. At a water temperature of 10 degrees C, utilization of P was also increased from 6 to 25%. However, feed consumption and gain of trout were very low at this water temperature and not influenced by the supplemental phytase.
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PMID:[Effect of a supplemental Aspergillus niger phytase on the utilization of plant phosphorus by rainbow trout (Oncorhynchus mykiss)]. 852 27

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 C before feeding) in a 3 x 2 factorial arrangement. A positive control diet was supplemented with inorganic P and provided .23% available P, .48% total P, and .60% Ca. Pigs were individually penned and fed their respective diets to appetite in four equal meals daily. There were no soaking x phytase interactions (P > .1 to .6) for growth performance criteria. Daily gain and gain/feed ratio were increased (P < .01) by soaking and increased linearly (P < .01) by phytase. Daily feed intake was increased linearly (P < .01) by phytase. There were soaking x phytase quadratic interactions (P < .01) for apparent P absorption criteria because soaking the 250 PU/kg diet increased P absorption similar to that obtained with the 500 PU/kg diet fed dry. Apparent P absorption criteria were increased by soaking (P < .01) and were increased linearly (P < .001) and quadratically (P < .03) by phytase. Phytase reduced fecal P excretion 37 to 40% with dry feeding (P < .03) and 48 to 49% with soaking (P < .01).
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PMID:Soaking increases the efficacy of supplemental microbial phytase in a low-phosphorus corn-soybean meal diet for growing pigs. 915 76

In two experiments, we investigated various factors that affect the estimation of the apparent total tract digestibility (ATTD) of DM, Ca, and total P in diets for growing-finishing pigs. In Exp. 1, the effects of age, housing, and calculation method (indicator [Cr2O3] vs 10-d total collection) were determined. Eighteen barrows and gilts (40 to 95 kg BW) were housed in six pens, and ATTD was estimated using the indicator method. Twelve barrows were housed in metabolic crates, and ATTD was estimated using both calculation methods. Dietary treatments were 1) a tapioca-soybean-barley-based diet, 2) Diet 1 supplemented with 400 FTU microbial phytase/kg of diet, and 3) a corn-soybean meal-based diet: In Exp. 2, six barrows (95 to 120 kg BW) were fed a phytase-deficient diet to investigate the effects of coprophagy (40 g fresh feces/kg of diet) and movement. Pigs were fed at 2.8 times maintenance requirement (418 kJ ME/BW.75); water supply was 2.5 L/kg of feed. The ATTD increased as BW increased. Phytase enhanced total P ATTD by an average of 18.1 percentage units. The ATTD of DM was higher and the ATTD of Ca and total P (P < .001) were lower in pigs housed in pens than in pigs housed in metabolic crates. Fecal consumption and movement led to numerical increases in Ca (P = .217) and total P (P = .103) ATTD. Estimates of Ca and total P ATTD using pigs in metabolic crates are lower than estimates in practice.
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PMID:Factors affecting phosphorus and calcium digestibility in diets for growing-finishing pigs. 926 61

This paper focuses on research with pigs carried out primarily at the ID-DLO in the Netherlands with the aim to reduce environmental pollution with nitrogen and phosphorus by changing the diet of the animals while maintaining their health and performance. The excretion of phosphorus (P) per growing pig has been more than halved in the last 20 years as a result of intensive nutritional research on P digestibility, requirements for P, and on the efficacy of microbial phytase in pig feeds. Also, nitrogen (N) excretion can be reduced substantially, but this knowledge has not been put into practice as yet. Preliminary results show that ammonia production can be reduced considerably by altering the diet. Studies to reduce the overproduction of sow manure (up to 98% water) showed that voluntary water consumption by non-pregnant sows under thermal neutral conditions was approximately 1.4 higher than the requirements. A water:feed ratio of 2:1 for pregnant sows kept at an ambient temperature of 18-20 degrees C had no detrimental effect on health and nutrient digestibility, but diminished urine production by 3.6 L/day, as compared to that with ad libitum water consumption.
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PMID:Impact of nutrition on reduction of environmental pollution by pigs: an overview of recent research. 932 55

Two trials were conducted to determine the effects on broiler chicken performance and health of reducing dietary phosphorus levels by treating feed with the enzyme phytase, formulating diets using high available phosphorus (HAP) corn, or when diets were formulated with HAP corn and treated with phytase. Cobb x Cobb male broiler chickens were placed in an experimental design consisting of four dietary treatments with six replicate pens of 50 broilers per pen. The dietary treatments consisted of untreated control feed, phytase-supplemented feed (500 U/kg), diets prepared with HAP corn, and diets prepared with HAP corn and supplemented with phytase. The chickens were maintained on these dietary treatments from 1 to 49 d of age with feed and water made available for ad libitum consumption. When the two trials were combined, there was a significant (P < or = 0.05) increase in body weight in the broilers fed the phytase treated diets at 49 d of age. The serum activity of alkaline phosphatase was significantly decreased in the diets supplemented with phytase, and serum cholesterol was significantly decreased in the diets prepared with HAP corn. These data indicate that total phosphorus can be reduced by at least 11% in diets prepared with HAP corn, or in diets supplemented with phytase, without affecting the performance or health of broiler chickens. When diets are prepared with HAP corn and supplemented with phytase, the dietary addition of total phosphorus can be reduced by at least 25% without affecting broiler chicken performance or health.
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PMID:Effect of dietary phytase and high available phosphorus corn on broiler chicken performance. 987 94


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