Biochemical properties of a thermostable phytase from Neurospora crassa.
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.
Zhou
Xiao-Ling
XL
The Key Laboratory of Industrial Biotechnology, Ministry of Education and School of Biotechnology, Southern Yangtze University, Wuxi, China.
Shen
Wei
W
Zhuge
Jian
J
Wang
Zheng-Xiang
ZX
D010832:6-Phytase / Q000235:genetics / Q000378:metabolism*; D004795:Enzyme Stability; D006863:Hydrogen-Ion Concentration; D009492:Neurospora crassa / Q000201:enzymology*; D013696:Temperature
D010832:6-Phytase