| 摘要 |
A novel lactase having a molecular weight of about 3x105, an optimum pH value of about 6.0, an optimum temperature of about 60 DEG C. and at least 1 of the ratio of the activity for hydrolyzing lactose to the activity for hydrolyzing a synthetic substrate: o-nitrophenyl- beta -D-galactopyranoside (Lact/ONPG ratio), which is produced by cultivating a microorganism of the genus Bacillus being capable of producing the enzyme, particularly Bacillus circulans LOB 377 (ATCC No. 31382) and isolating from the culture broth. This novel lactase is characteristic in the excellent thermostability and the high Lact/ONPG ratio and hence is useful for treating milk and milk products as well as for preventing diarrhea due to lactose intolerance, especially in babies and infants. |
