PURPOSE: To obtain the novel enzyme stable at a pH during the use of a reagent for measuring CO2 without being inhibited with ADP by culturing a microorganism, belonging to the genus Acetobacter and having the ability to produce a specific thermostable phosphoenolpyruvate carboxylase.
CONSTITUTION: A strain, belonging to the genus Acetobacter and having the ability to produce a thermostable phosphoenolpyruvate carboxylase (e.g. Acetobacter pasteurianus IFO14814) is cultured in a nutrient culture medium to collect the resultant product from the culture. Thereby, the objective thermostable phosphoenolpyruvate carboxylase, capable of catalyzing the reaction expressed by the formula and having the following physico-chemical properties is obtained: optimum action pH: 7.0; pH stability: pH6.0-8.5 (treatment at 25°C for 24hr); optimum action temperature: 60°C; thermostability: stable to 55°C (treatment at pH7.0 for 15min) and molecular weight: 390000±10000 (measured by a gel filtration method) and 100000±5000 (measured by an SDS- PAGE method).
HATTORI SHIZUO
TEJIMA SHINICHI
