phosphorus (p) is a macro mineral in broiler nutrition. in growing broilers, besides its requirement for proper bone development, it is also involved in almost all metabolic processes. poor p availability results in decreased productivity and poor health status.phosphorus availability from plant derived feeds is affected by an anti-nutritional factor “phytate”, which forms a variety of insolubl...

Phytic acid (myo-inositol hexakisphosphate, InsP(6)) hydrolysis by Bacillus phytase (PhyC) was studied. The enzyme hydrolyses only three phosphates from phytic acid. Moreover, the enzyme seems to prefer the hydrolysis of every second phosphate over that of adjacent ones. Furthermore, it is very likely that the enzyme has two alternative pathways for the hydrolysis of phytic acid, resulting in t...

From the last few years, the inclusion of microbial phytase in poultry diets has increased significantly, mainly in response to heightened concerns over phosphorus pollution of the environment and as cheaper means to make phosphorus available to birds from phytate. Phytate is the major form of phosphorus, abundantly found in cereal grains, beans and oilseed meals used in poultry diet but the mo...

The overall objective of the studies reported here was to evaluate the growth and nutrient utilization responses of pigs to dietary supplementation of phytate- or nonstarch polysaccharide-degrading enzymes. In Exp. 1, growth performance and nutrient digestibility responses of forty-eight 10-kg pigs to dietary supplementation of phytase or a cocktail of xylanase, amylase, and protease (XAP) alon...

Previously, we determined the DNA and amino acid sequences as well as biochemical and biophysical properties of a series of fungal phytases. The amino acid sequences displayed 49-68% identity between species, and the catalytic properties differed widely in terms of specific activity, substrate specificity, and pH optima. With the ultimate goal to combine the most favorable properties of all phy...

A study was conducted to determine the additive effects of calcium (Ca) levels and the enzyme phytase, organic acids (citric, ascorbic acid), vitamin D on broiler performance and nutrient digestibility (d 3 1 to 21) in wheat-based diet. Broilers were fed the following diets at either 7.9, or 9 g/kg of dietary Ca with: 1) a negative control wheat-based diet, 3.15 g/kg available phosphorus (P) (N...

Phytase (myo-inositol-hexakisphosphate phosphohydrolase, EC 3.1.3.8) has been purified from 5-7-day-old maize (Zea mays) seedlings, using a four-step purification procedure. The native protein has a molecular mass of about 76 kDa and is built up from two 38 kDa subunits. The pH and temperature optima of the purified enzyme were respectively 4.8 and 55 degrees C. The apparent Km for phytate was ...

The phyA gene encoding an extracellular phytase from the thermophilic fungus Thermomyces lanuginosus was cloned and heterologously expressed, and the recombinant gene product was biochemically characterized. The phyA gene encodes a primary translation product (PhyA) of 475 amino acids (aa) which includes a putative signal peptide (23 aa) and propeptide (10 aa). The deduced amino acid sequence o...

Minerals can readily bind to phytic acid and thus have the potential to form mineral±phytate complexes that may be resistant to hydrolysis by phytase activity of animal, plant and microbial origin. In simple solution, at pH 7.0, mineral concentrations from 0.053 mM for Zn up to 4.87 mM for Mg caused a 50% inhibition of phytate-P hydrolysis by microbial phytase. The rank order of mineral potency...

Naturally-occurring phytases having the required level of thermostability for application in animal feeding have not been found in nature thus far. We decided to de novo construct consensus phytases using primary protein sequence comparisons. A consensus enzyme based on 13 fungal phytase sequences had normal catalytic properties, but showed an unexpected 15-22 degrees C increase in unfolding te...