| 摘要 |
PURPOSE:To stably produce a large amount of acidic urease by cultivation in a nutrient culture medium by selecting a specific microorganism and gene as a host microorganism and a utilizable gene. CONSTITUTION:A DNA of a microorganism capable of donating acidic urease gene is separated and purified. The resultant DNA is then cleaved using ultrasonic waves, a restriction enzyme, etc., and the cleaved DNA is bound to a vector converted into a linear shape by cleaving at the smooth terminal or adhesive terminal of both DNAs and cyclized with a DNA ligase, etc. Thereby, a recombinant DNA vector is obtained. In producing the acidic urease, the aforementioned transformed microorganism is cultured in a nutrient culture medium to normally produce and accumulate the acidic urease in a culture solution or microbial cells. After completing the culture, the objective acidic urease may be separated and purified from the obtained culture solution or microbial cells. A microorganism of the genus Lactobacillus, preferably Lactobacillus fermentum JCM5869 (FERM BP-3050) is cited as the donative microorganism which is a donor of the DNA. |
