Enzymes of Opuntia ficus-indica (L.) Miller with potential industrial applications-I

We report on the screening of different enzymes such as arylamidases, lipas es, proteinases, and glucosidases in plant extracts of the Cactaceae family , genus Opuntia, as well as on a newly purified plant proteases from O. fic us-indica fruit extracts. These proteinases showed the maximum activity at pH 5.2 and 55 degrees C and FTC-casein was the best of the screened substra tes. Proteolytic activities were activated by anti-oxidant compounds and by some divalent cations. These proteinases were efficiently inhibited by cys tein proteinase inhibitors and by 1,10-phenanthroline. The estimated M-r fo r the main proteolytic activity was about 23.2 kDa. The results on milk clo tting characteristics suggest a potential use of the fruit cystein enzymes of this plant in dairy industries.