Alkaline protease for detergent use etc. - having max. activity at pH 10 to pH 11 and at 45 to 50 degrees C

摘要

Alkaline protease, API-21, has the following properties: (1) It hydrolyses casein under alkaline conditions, the optimal pH being 10-11 and optimal temp. being 45-50 deg.C. (2) There is no decrease in enzymic activity after 10 minutes at pH 10 and at 40 deg.C, but the same at 50 deg.C gives a 90% decrease in activity. Deactivation is produced within 10 minutes at 50 deg.C, pH 8. The enzyme is stable to cooling and may be freeze dried. (3) API -21 has a mol. wt. of 22000, and isoelectric point of 7.4, uv absorption maxima at 275-282nm, a serine residue at the active site, and a characteristic IR spectrum. The enzyme is isolated from a new bacterium Bacillus sp. nov. NKS - 21 FERM BP -93. Aerobic cultures of NKS-21 are sepd. to give the culture prod. and a clear soln. Addn. of an organic solvent such as ethanol to the clear soln. pptes. API -21. API -21 may be used in the leather, food, textile, fibre, medical and pharmaceutical industries. It is esp. useful as a detergent additive, being a very active at a lower temp. than most commercially-available enzymes. It may therefore be used with very delicate fabrics.