Zhou Xiao-Ling, Shen Wei, Zhuge Jian, Wang Zheng-Xiang
The Key Laboratory of Industrial Biotechnology, Ministry of Education and School of Biotechnology, Southern Yangtze University, Wuxi, China.
FEMS Microbiol Lett. 2006 May;258(1):61-6. doi: 10.1111/j.1574-6968.2006.00205.x.
A gene (Ncphy) encoding a putative phytase in Neurospora crassa was cloned and expressed in Pichia pastoris, and the biochemical properties of the recombinant protein were examined in relation to the phytic acid hydrolysis in animal feed. The recombinant phytase (rNcPhy) hydrolyzed phytic acid with a specific activity of 125 U mg-1, Km of 228 micromol L-1, Vmax of 0.31 nmol (phosphate) s-1 mg-1, a temperature optimum of 60 degrees C and a pH optimum of 5.5 and a second pH optimum of 3.5. The enzyme displayed pH stability around pH 3.5-9.5 and showed satisfactory thermostability at 80 degrees C. The phytase from N. crassa has potential for improving animal feed processing at higher temperatures.
克隆了粗糙脉孢菌中一个编码假定植酸酶的基因（Ncphy），并在毕赤酵母中表达，还针对动物饲料中植酸水解情况检测了重组蛋白的生化特性。重组植酸酶（rNcPhy）水解植酸的比活性为125 U mg-1，米氏常数（Km）为228 μmol L-1，最大反应速度（Vmax）为0.31 nmol（磷酸盐）s-1 mg-1，最适温度为60℃，最适pH为5.5，还有一个第二最适pH为3.5。该酶在pH 3.5 - 9.5左右表现出pH稳定性，在80℃时显示出良好的热稳定性。粗糙脉孢菌的植酸酶在较高温度下改善动物饲料加工方面具有潜力。
