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- Title
High Level Expression of an Acid-Stable Phytase from Citrobacter freundii in Pichia pastoris.
- Authors
Zhao, Wei; Xiong, Aisheng; Fu, Xiaoyan; Gao, Feng; Tian, Yongsheng; Peng, Rihe
- Abstract
To obtain a high level expression of phytase with favorable characteristics, a codon-optimized phytase gene from Citrobacter freundii was synthesized and transferred into Pichia pastoris. Small-scale expression experiments and activity assays were used to screen positive colonies. After purified by Ni-NTA agarose affinity column, the characterizations of the recombinant phytase were determined. The recombinant phytase (r-phyC) had two distinct pH optima at 2.5 and 4.5 and an optimal temperature at 50 °C. It retained more than 80% activity after being incubated under various buffer (pH 1.5-8.0) at 37 °C for 1 h. The specific activity, Km, and Vmax values of r-phyC for sodium phytate were 2,072 ± 18 U mg, 0.52 ± 0.04 mM, and 2,380 ± 84 U mg min, respectively. The enzyme activity was significantly improved by 1 mM of K, Ca, and Mg. These characteristics contribute to its potential application in feed industry.
- Subjects
GENE expression; PHYTASES; CITROBACTER; PICHIA pastoris; ENZYMES; FEED industry; PHOSPHORUS; ANIMAL nutrition; MATHEMATICAL optimization
- Publication
Applied Biochemistry & Biotechnology, 2010, Vol 162, Issue 8, p2157
- ISSN
0273-2289
- Publication type
Article
- DOI
10.1007/s12010-010-8990-4