Huang Huoqing, Luo Huiying, Wang Yaru, Fu Dawei, Shao Na, Wang Guozeng, Yang Peilong, Yao Bin
Department of Microbial Engineering, Feed Research Institute, Chinese Academy of Agricultural Sciences, Beijing, People's Republic of China.
Appl Microbiol Biotechnol. 2008 Sep;80(3):417-26. doi: 10.1007/s00253-008-1556-5. Epub 2008 Jun 12.
Two novel phytase genes belonging to the histidine acid phosphatase family were cloned from Yersinia rohdei and Y. pestis and expressed in Pichia pastoris. Both the recombinant phytases had high activity at pH 1.5-6.0 (optimum pH 4.5) with an optimum temperature of 55 degrees C. Compared with the major commercial phytases from Aspergillus niger, Escherichia coli, and a potential commercial phytase from Y. intermedia, the Y. rohdei phytase was more resistant to pepsin, retained more activity under gastric conditions, and released more inorganic phosphorus (two to ten times) from soybean meal under simulated gastric conditions. These superior properties suggest that the Y. rohdei phytase is an attractive additive to animal feed. Our study indicated that, in order to better hydrolyze the phytate and release more inorganic phosphorus in the gastric passage, phytase should have high activity and stability, simultaneously, at low pH and high protease concentration.
从罗德氏耶尔森菌和鼠疫耶尔森菌中克隆出两个属于组氨酸酸性磷酸酶家族的新型植酸酶基因，并在毕赤酵母中表达。两种重组植酸酶在pH 1.5 - 6.0（最适pH 4.5）时具有高活性，最适温度为55℃。与来自黑曲霉、大肠杆菌的主要商业植酸酶以及来自中间耶尔森菌的一种潜在商业植酸酶相比，罗德氏耶尔森菌植酸酶对胃蛋白酶更具抗性，在胃部条件下保留更多活性，并且在模拟胃部条件下从豆粕中释放出更多无机磷（两到十倍）。这些优异特性表明，罗德氏耶尔森菌植酸酶是一种有吸引力的动物饲料添加剂。我们的研究表明，为了在胃部更好地水解植酸盐并释放更多无机磷，植酸酶应同时在低pH和高蛋白酶浓度下具有高活性和稳定性。
