Embrapa Instrumentation, Rua XV de Novembro 1452, Sao Carlos, SP, 13560-970, Brazil.
Graduate Program of Chemical Engineering, Federal University of São Carlos, Sao Carlos, SP, 13565-905, Brazil.
Appl Biochem Biotechnol. 2020 Jan;190(1):270-292. doi: 10.1007/s12010-019-03116-9. Epub 2019 Jul 25.
The enzyme phytase has important applications in animal feed, because it favors the bioavailability of phosphorus present in phytate, an antinutritional compound widely found associated with plant proteins. However, for feed applications, the phytase must withstand high temperatures during the feed pelleting process, as well as the gastrointestinal conditions of the animal. This work evaluates the feasibility of immobilizing phytase on hydroxyapatite (HA) nanoparticles, in order to improve its properties. HA is a material with excellent physicochemical characteristics for enzyme immobilization, and it can also act as an inorganic source of phosphorus and calcium in animal feed. The strong affinity of the phytase for the support resulted in rapid adsorption, with total immobilization yield and recovered activity greater than 100%. After immobilization, the phytase showed a broader activity profile in terms of pH and temperature, together with considerably higher thermoresistance at 80 and 90 °C. As a proof of concept, it was shown that the phytase immobilized on HA presented good resistance to acidic conditions and resistance to proteolysis when passing through simulated gastrointestinal conditions of fish. The findings showed that phytase immobilized onto HA presents suitable properties and has great potential for use in animal feed.
植酸酶在动物饲料中有重要的应用，因为它有利于植酸中磷的生物利用，植酸是一种广泛存在于植物蛋白中的抗营养化合物。然而，对于饲料应用，植酸酶必须在饲料制粒过程中耐受高温以及动物的胃肠道条件。本工作评估了将植酸酶固定在羟基磷灰石（HA）纳米颗粒上以改善其性能的可行性。HA 是一种具有优异理化特性的酶固定化材料，它也可以作为动物饲料中磷和钙的无机来源。植酸酶与载体之间的强亲和力导致快速吸附，总固定化产率和回收活性均大于 100%。固定化后，植酸酶在 pH 和温度方面表现出更宽的活性谱，并且在 80 和 90°C 时具有相当高的耐热性。作为概念验证，结果表明固定在 HA 上的植酸酶在通过模拟鱼类胃肠道条件时表现出良好的耐酸性和抗蛋白水解性。研究结果表明，固定在 HA 上的植酸酶具有合适的性质，在动物饲料中有很大的应用潜力。
