| 摘要 |
PROBLEM TO BE SOLVED: To obtain a hyper-thermostable β-glycosidase resistant to deactivation even in an organism growing at a high temperature for the production of low- lactose milk by culturing a host cell containing a vector containing a DNA coding for the enzyme. SOLUTION: A chromosome DNA is separated from a hyper-thermophilic archaebacterium such as thermostable thiolprotease-producing KOD-1 strain (FERM P-15009, etc.), a library containing the chromosome DNA is prepared and screened to obtain a DNA coding for hyper-thermostable β-glycosidase, a transformant is prepared from the DNA by recombination technique and the transformant is cultured to obtain the objective hyper-thermostable β- glycosidase. The enzyme has an optimum pH of preferably about 100 deg.C and an optimum pH of preferably about 6.5. The above DNA contains the sequence of formula having a length of 1,452 bp. |
