الفهرس 
Preparation and extraction of crude enzymesOnly 14 pages are availabe for public view
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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 .