Novozymes A/S, Krogshoejvej 36, 2880 Bagsvaerd, Denmark.
J Sci Food Agric. 2011 Jun;91(8):1398-405. doi: 10.1002/jsfa.4324. Epub 2011 Mar 8.
Phytases increase utilization of phytate phosphorus in feed. Since wheat is rich in endogenous phytase activity it was examined whether wheat phytases could improve phytate degradation compared to microbial phytases. Moreover, it was investigated whether enzymatic degradation of phytate is influenced by the matrix surrounding it. Phytate degradation was defined as the decrease in the sum of InsP₆ + InsP₅.
Endogenous wheat phytase effectively degraded wheat Ins₆ + InsP₅ at pH 4 and pH 5, while this was not true for a recombinant wheat phytase or phytase extracted from wheat bran. Only microbial phytases were able to degrade InsP₆ + InsP₅ in the entire pH range from 3 to 5, which is relevant for feed applications. A microbial phytase was efficient towards InsP₆ + InsP₅ in different phytate samples, whereas the ability to degrade InsP₆ + InsP₅ in the different phytate samples ranged from 12% to 70% for the recombinant wheat phytase.
Wheat phytase appeared to have an interesting potential. However, the wheat phytases studied could not improve phytate degradation compared to microbial phytases. The ability to degrade phytate in different phytate samples varied greatly for some phytases, indicating that phytase efficacy may be affected by the phytate matrix.
植酸酶可以提高饲料中植酸磷的利用率。由于小麦富含内源性植酸酶活性，因此研究了小麦植酸酶是否可以比微生物植酸酶更有效地降解植酸盐。此外，还研究了植酸盐的酶解是否受其周围基质的影响。植酸盐的降解定义为 InsP₆ + InsP₅的减少量。
内源性小麦植酸酶在 pH 值为 4 和 5 时能有效地降解小麦 Ins₆ + InsP₅，而重组小麦植酸酶或从麦麸中提取的植酸酶则不然。只有微生物植酸酶能够在 pH 值为 3 到 5 的整个范围内降解 InsP₆ + InsP₅，这对于饲料应用很重要。一种微生物植酸酶对不同植酸盐样品中的 InsP₆ + InsP₅都有效，而重组小麦植酸酶对不同植酸盐样品中 InsP₆ + InsP₅的降解能力从 12%到 70%不等。
小麦植酸酶似乎具有很大的潜力。然而，与微生物植酸酶相比，研究中的小麦植酸酶并不能提高植酸盐的降解率。一些植酸酶对不同植酸盐样品中植酸盐的降解能力差异很大，表明植酸酶的功效可能受到植酸盐基质的影响。
