Enzyme Characteristics of Phytase from Spicaria Harting 26-13-4

A phytase-producing strain was isolated from humous soil near the root of crops in Heilongjiang province in China. According to the morphological results by microscope and transmission electron microscope, strain No. 26-13-4 was identified as Spicaria Harting. The enzyme characteristics of Spicaria Harting phytase were studied. The optimal temperature and pH for sodium-phytate hydrolysis by Spicaria Harting phytase was 45°C and 5.0 respectively. Phytase had better heat stability as temperature below 45°C. The phytase activity remained 90% when pH was 4.5 to 6.0. Fe²⁺ evaluated phytase activity as its concentration blow 455 mg·L^-1. Phytase was actived by Mn²⁺ or Ca²⁺ when their concentration less than 92 mg·L^-1 but inhibited when their concentration more than 92 mg·L^-1. Phytase was also inhibited by Fe³⁺, Cu²⁺, Mg²⁺, Zn²⁺, Al³⁺. There was no effect with K⁺ and low concentration of Fe³⁺. The Km was about 4.4×10^-5 mol·L^-1 when sodium phytase as substrate. The enzyme characteristics of Spicaria Harting 26-13-4 phytase make it could apply to food and feed to reduce the phosphorus exhausted to environment.