Thermostable collagenolytic activity of a novel thermophilic isolate, Bacillus sp strain NTAP-1

We isolated an acidophilic thermophile belonging to the genus Bacillus, str ain NTAP-1, which secreted a thermostable collagenolytic activity into the culture medium. The collagenolytic activity exhibited an optimum pH for Azo coll hydrolysis of pH 3.9 and was not completely inhibited by 10 mM ethylen ediaminetetraacetic acid (residual activity, 63%), suggesting that Bacillus NTAP-1 produces a novel acid proteinase with highest activity for collagen . The collagenolytic activity was thermostable; more than 80% of the origin al activity was retained after incubation of the culture supernatant at pH 4.0 and 60 degrees C for 4 h.