Schöner, F. J., Hoppe, P. P. und Schwarz, G. (1991): Vergleich der Effekte von mikrobieller Phytase und anorganischem Phosphat auf die Leistungen und die Retention von Phosphor, Calcium und Rohasche bei
Ten different strains of
, isolated from composting soils were found to produce phytase when grown on PSM medium. The wild type strain CM was found to produce maximum amount of phytase (4.33 units/g DW substrate). Culturing
strain CM on medium containing wheat bran and optimizing other culture conditions (carbon source, media type, nitrogen source, level of nitrogen, temperature, pH, inoculum age, inoculum level and moisture), increased the phytase yield to 13.26 units/g substrate. This culture was further subjected to UV mutagenesis for developing phytase hyperproducing mutants. The mutant (TL-7) showed 2.29-fold increase in phytase activity as compared to the parental strain. Employing Box-Behnken factor factorial design of response surface methodology resulted in optimized phytase production (32.19 units/g of substrate) by mutant TL-7. A simple two-step purification (40.75-folds) of phytase from mutant TL-7 was achieved by anion exchange and gel filtration chromatography. The purified phytase (∼54 kDa) was characterized to be optimally active at pH 5.0 and temperature 70 °C, though the enzyme showed ∼70% activity over a wide pH and temperature range (2.0–10.0 and 30–90 °C, respectively). The phytase showed broad substrate specificity with activity against sodium phytate, ADP and riboflavin phosphate. The phytase from
was thermoacidstable as it showed up to 70% residual activity after exposure to 70 °C at pH 3.0 for 120 min. The enzyme showed K
4.55 μM and V
0.833 μM/min/mg against sodium phytate as substrate.
Authors:J. D. T. Arruda-Neto, A. C. Cestari, C. B. Zamboni, M. Saiki, G. P. Nogueira, L. E. C. Fonseca, M. V. Manso-Guevara, A. Deppman, V. P. Likhachev, J. Mesa, O. A. M. Helene, S. A. C. Jorge, M. N. Martins, A. N. Gouveia, O. Rodriguez, F. Guzmán, and F. Garcia
Neutron activation analysis has been used to study uranium incorporation in poultry bones as function of chow doped with: (a) uranium (20 ppm); (b) U-doped food (20 ppm) plus phytase (120 ppm) and (c) U-doped food (20 ppm) plus phytase (180 ppm). To investigate this situation experiments involving several groups of Cobb broilers was performed. Two animals per group were sacrificed weekly up to their adultness and uranium concentration in the tibia was measured. It was observed that the concentration of uranium (µg U/g bone) is decreasing all along the animal life spanning period of 14-42 days. This behavior suggests that the skeleton mass is growing faster than the corresponding accumulation of uranium. The administration of phytase seems not to alter this scenario.
A full length phytase (TaPAPhy_a1.1) gene was cloned and sequenced from Indian wheat cultivar DBW17. The 2,060 bp sequence has four introns of 63, 90, 94, 103 bp and encodes a polypeptide of 548 amino acids. N-terminal residues 5 to 19 contain a signaling peptide (SP) targeted to the vacuole. The predicted molecular weight and isoelectric point were 60.53 kDa and 6.74, respectively. A phylogenetic tree analysis revealed that TaPAPhy_a1.1 clustered on a branch with PAPhy_a1 from Aegilops tauschii cultivar NGB 9855. A structural model of TaPAPhy_a1.1 protein showed a single chain dimer containing two metal ions (Fe and Zn) bound at its active site. It belongs to the metallophosphoesterase group containing a characteristic set of seven amino acid residues (Asp, Asp, Tyr, Asn, His, His, His) involved in metal ligation. The full length TaPAPhy_a1.1 gene sequence from this investigation can be used for allele mining studies to identify superior alleles for higher phytase levels for improving the nutritional quality of wheat.
Authors:G. Šimić, A. Lalić, D. Horvat, I. Abičić, and I. Beraković
, L. , Haraldsson , A.K. , Andersson , R. , Alminger , M. , Sandberg , A.S. & Amen , P.
2002 : Effects of malting on ß-glucanase and phytase activity in barley grain . J. Sci. Food Agr. , 82 , 904 – 912
Authors:Nehla Labidi, Sana Snoussi, Manel Ammari, Wissal Metoui, N. Ben Yousfi, Lamia Hamrouni, and C. Abdelly
Loussert, R., Brousse, G. (1978) L’olivier . Editions Maisonneuve et Larose, pp. 167–175.
Lung, S. C., Leung, A., Kuang, R., Wang, Y., Leung, P., Lim, B. L. (2008) Phytase activity in tobacco (Nicotiana tabacum