PURIFICATION AND CATALYTIC PROPERTIES OF A PHYTASE FROM SCALLION (ALLIUM-FISTULOSUM L.) LEAVES

Levels of phytase comparable to that in wheat germ were detected in a variety of fresh vegetables. Scallion leaf phytase was purified 31 000 -fold to an activity of 500 mu mol min(-1) mg(-1) at 37 degrees C and had a K-m of 200 mu M for inositol hexakisphosphate and maximum activi ty at pH 5.5. The enzyme had a temperature optimum of 51 degrees C and was inactivated by preincubation for 10 min at 65 degrees C. The prod uct specificity appeared similar to that of wheat phytase and was not altered by a 10-fold excess of magnesium. Vegetable phytases may be an alternative to seed and microbial phytases for use in the processing of food and feed products.