Department of Biotechnology, Indian Institute of Technology Roorkee, Roorkee, Uttarakhand 247667, India.
Department of Biological Sciences, Indian Institute of Science Education and Research, Kolkata 741246, India.
Bioresour Technol. 2018 Feb;249:1000-1008. doi: 10.1016/j.biortech.2017.10.106. Epub 2017 Nov 4.
A novel protein tyrosine phosphatase like phytase (PTPLP), designated as PhyLf from probiotic bacterium Lactobacillus fermentum NKN51 was identified, cloned, expressed and characterized. The recombinant PhyLf showed specific activity of 174.5 U/mg. PhyLf exhibited strict specificity towards phytate and optimum temperature at 60 °C, pH 5.0 and ionic strength of 100 mM. K and K of PhyLf for phytate were 0.773 mM and 84.31 s, respectively. PhyLf exhibited high resistance against oxidative inactivation. PhyLf shares no homology, sans the active site with reported PTLPs, warranting classification as a new subclass. Dephytinization of durum wheat and finger millet under in vitro gastrointestinal conditions using PhyLf enhanced the bioaccessibility of mineral ions. Probiotic origin, phytate specificity, resistance to oxidative environment and gastric milieu coupled with ability to release micronutrients are unique properties of PhyLf which present a strong case for its use in ameliorating nutritional value of cereals and animal feed.
从益生菌乳杆菌 NKN51 中鉴定、克隆、表达和表征了一种新型的蛋白酪氨酸磷酸酶样植酸酶（PTPLP），命名为 PhyLf。重组 PhyLf 的比活性为 174.5 U/mg。PhyLf 对植酸表现出严格的特异性，最适温度为 60°C，pH 值为 5.0，离子强度为 100 mM。PhyLf 对植酸的 K 和 K 分别为 0.773 mM 和 84.31 s。PhyLf 对氧化失活具有很高的抗性。PhyLf 与报道的 PTLPs 没有同源性，除了活性位点，因此被归类为一个新的亚类。在体外胃肠道条件下，使用 PhyLf 对硬质小麦和手指小米进行脱植酸处理，提高了矿物质离子的生物利用度。益生菌来源、植酸特异性、对氧化环境和胃环境的抗性以及释放微量营养素的能力是 PhyLf 的独特特性，这为其在改善谷物和动物饲料的营养价值方面的应用提供了有力的依据。
