Identification and characterization of a phytase of potential commercial interest

Effect of a mixed substrate on phytase production by Rhizopus oligosporus MTCC 556 using solid state fermentation and determination of dephytinization activities in food grains

“…Generally, the Rhizopusderived enzyme exhibits an optimal phytase activity level at 50-60 o C and at a pH of 2.0 to 6.0. These are important values for feed applications and commercial perspectives (5,28). Agricultural feed additives containing phytic acid have caused nutritional deficiencies and higher rates of environmental pollution due to a maximum load of phosphorus excreted by monogastric animals due to lack of a phytic acid degrading enzyme in the gastrointestinal tract (2).…”

“…The maximum amount of phytase hydrolytic products was obtained using RF and CF. Carbohydrate rich food grains produced the maximum amounts of phytase hydrolytic products using R. oligosporus phytase, perhaps due to high carbohydrate contents (30.5%) (5). In the presence of a glycosylatic enzyme, the R. oligosporus phytase has been shown to exhibit high catalytic efficiency and stability (30).…”

“…Recent studies have focused on phytase production by Rhizopus sp. and phytase from R. oligosporus has been purified and characterized by Casey and Walsh (5). Preference for use of R. oligosporus phytase in animal feed area makes it a promising candidate for phytic acid hydrolysis and commercial application.…”

Effect of different cultural conditions for phytase production by Aspergillus niger CFR 335 in submerged and solid-state fermentations

“…The metal ion requirement of Bacillus subtilis phytase has been studied and their removal from the medium by EDTA resulted in complete inactivation of the product while the enzymatic activities of fungal phytases are reported not to require metal ion [20]. Rhizopus oligosporus phytase activity was found to be unaVected or moderately stimulated by a range of metal ions [4]. Similarly, Aspergillus niger CFR 335 phytase was activated in presence of Ca 2+ in SmF at 0.01% (0.036 moles/L) level indicating Ca 2+ ion dependency of phytase, which might be acting as its cofactor.…”

Nutritional and energetic value of rice by-products, with or without phytase, for growing pigs

“…According to HURRELL (2004), removing phytic acid facilitates ingredient digestion because it prevents the chelation of myoinositol hexaphosphate molecules with multivalent metal ions, especially zinc and calcium. Phytate also binds with proteins, amino acids, starch and enzymes such pepsin, trypsin and alpha amylase, compromising digestion and absorption (CASEY & WALSH, 2004). The low nutrient digestibility observed with DRB compared to DRB+Phy was also observed by SILVA et al (2005), when phytase supplementation improved the apparent ileal digestibility of amino acids from defatted rice bran and soybean meal in growing pigs.…”