Phytase produced from Citrobacter braakii

摘要

PURPOSE: Phytase derived from Citrobacter braakii is provided, which phytase can be used in domestic animal feed because it has improved enzyme activity, cannot be decomposed in the stomach and intestines because it has tolerance to hydrolase. CONSTITUTION: The phytase derived from Citrobacter braakii has the following properties: (a) 47 kDa of molecular weight on SDS-PAGE, (b) pH 3.5 to 4.5 of optimal pH, (c) 45 to 55 deg. C of optimal temperature, (d) substrate specificity wherein the substrates are phytate, p-nitrophenyl phosphate, tetrasodium pyrophosphate, ATP or ADP, (e) 3.5 to 0.5 mM of Michaelis constant when the substrate is phytate, and (f) high tolerance to a protein decomposing enzyme selected from pepsin, trypsin, papain, elastase and pancreatin, wherein the phytase comprises the amino acid sequence set forth in SEQ ID NO: 2 in the N-terminal. A gene encoding the phytase derived from Citrobacter braakii has the nucleotide sequence set forth in SEQ ID NO: 6. A phytase producing Citrobacter braakii YH-15(KCCM 10427) is provided.