الفهرس | Only 14 pages are availabe for public view |
Abstract Chitinase and laminarinases (A and B) were qualitatively and quantitatively determined in vegetative parts and seeds (dry and germinated) of some plants representing eleven families. Sugar beet leaves were found to be the most considerable source for these enzymes as demonstrated from the screening studies, and so these leaves were used for extraction and purification of the three enzymes. The three enzymes were extracted with water and purified by using CNfL1 )2 so4 then gel filtration on Sephadex G-120 followed by Sephadex G-200 columns. The molecular weights of the purified chitinase and laminarinases (A and B) as determined by gel filtration on Sephadex G-200 column were 64, 24 and 10 kDa, respectively. The . effect of different temperatures and buffers on the activity and stability of the three enzymes have been studied. The effect of different activators and inhibitors were also tested. The Km values of chitinase and laminarinases (A and B) were 0.2, 0.27 and 0.074 %, respectively. The purified chitinase and larninarinases (A and B) were found to have specific hydrolytic effect on 13-1,4; 13-1,3 and 13-1,3 glycosidic linkages, respectively. The three enzymes were able to inhibit the growth and to lyse the cell walls of pathogenic fungi such as Aspergillus species . |