OCCURRENCE OF A THERMOACIDOPHILIC CELL-BOUND EXO-PECTINASE IN ALICYCLOBACILLUS-ACIDOCALDARIUS

Alicyclobacillus acidocaldarius was able to degrade pectin under therm oacidophilic conditions of high temperature and acidity. Both extracel lullar and cell-bound pectolytic activities were found (28 and 72 % of total activity, respectively). When A. acidocaldarius was subjected t o lysozyme or sonication, more than 50 % of the activity was found to be bound with the cell debris. The cell-bound enzyme presented princip ally exopectolytic activity. SDS-PAGE and zymogram showed that the est imated molar mass of the crude enzyme was 52 kDa. pH optimum was betwe en 15 and 2.0 and the enzyme was thermostable at 70 degrees C for 1 h at pH 2.0.