Abstract
Bacillus No. P-4-N isolated from soil produced an alkaline polygalacturonase (APGase) in alkaline media. The characteristic point of this microorganism was especially good growth in alkaline media, and that very poor growth was detected in neutral media such as nutrient broth. An important factor for the production of APGase was the addition of manganese to the medium containing sodium carbonate, which was also another imporant factor. The APGase of Bacillus No. P-4-N was purified by Sephadex G-100 and DEAE-cellulose columns followed by Sephadex G-200 gel filtration. The enzyme was most active at pH 10_??_10.5 and stable pH was about 6. The enzyme was heat stable: about 80% of the activity remained after heating at 80°C for 5 min. Calcium ion was effective to stimulate the activity and to stabilize the enzyme. The molecular weight estimated by Sephadex gel filtration method was 6_??_7×104. The enzyme was completely inactivated by EDTA, but not by urea, NaCl and PCMB. The enzyme split poly, galacturonic acid at random and yielded galacturonic acid, digalacturonic acid and higher oligogalacturonic acids. If the enzyme is a single entity, it is a type of liquefying APGase.
