In this work we study the kinetic of Catalase and Guaiacol peroxidase and the effect of : pH, temperature, enzyme concentration and substrate concentration on the activity of these enzymes in the mesocotyles of Zea mays ( Ghoto82 ) 6 day old.
تاثير الميكورايزا في مكافحة مرض سقوط بادرات البندورة من خلال تنشيط إفراز بعض الهرمونات والإنزيمات الدفاعية
45 samples were collected from various sources (soil, degraded wood and
mushroom compost) from three cities (Damascus, Homs and Lattakia). 18
Trichoderma isolates were isolated and identified by microscope. These isolates
were screened using CMC m
edium with Congo red dy to identify their ability
to produce cellulase complex. The amount of enzyme production was
determined depending on the radius of clear zone around the colony. Results
showed that the most productive isolate was Tr with radius 7 ± 0.2 cm followed
by Tg and Ti. Optimization of cellulase production was performed using
response surface methodology (RSM). The optimal parameters were:
temperature 29.5 ˚C, pH = 6، incubation time 4 days, aeration speed 175 rpm
and wheat straw concentration 3%. All studied parameters had significant
effect on cellulase enzyme activity.
A partial purification was performed for the fungal hydroxycinnamic acid
esterase (HCAE) from Humicola sp. by precipitation using either ammonium
sulfate or acetone.
β-galactosidase enzyme was isolated from the new born goat brain by nine
methods, It was found that the sodium acetate 0.2 Mole/Liter +0.2Mole/Liter
NaCl PH5 method have given the highest specific activity of crude enzyme in
comparison with the ot
her methods. Also, this enzyme was purified by using
four methods, the second one (cold acetone) was the butter. As a result the
purification fold was about 135.46 times and the yield about 77.14% by using
Sephacryl S200 (second step). This enzyme is 187.437 KDa as a molecular
weight.
Some characteristics of β-galactosidase enzyme that was isolated from a new
born goat brain were studied. This study concluded that the enzyme is glucoenzyme
in which the carbohydrate part constitutes 22.1% in accordance with
phenol –sulfate acid
method.
The optimum pH for the enzyme activity is 5.5. The enzyme lost its activity
completely at pH8.5, and showed great stability at the range of pH 4-6.
The results indicated that the optimum temperature for the enzyme activity
is 55Co at the optimum pH. The stability temperature for the enzyme is
35-60Co.
The analytical results of 5%lactose solution hydrolyzed by the enzyme have
indicated that the hydrolysis rate is between 40% after 60 minutes, to 95%
after 270 minutes.
The present work was undertaken to study the properties and varations in
the activities of castor bean lipase under different condition.
Enzymes were extracted from dormant seed by phosphate buffer, then
characterizations were conducted.
Ten isolates of fungi-producing amylase were isolated from six different
sources (different kinds of soils - air-spoilage bread) on malt extract agar
(MEA) and potato dextrose agar (PDA). Four isolates were identified in
Museum of Natural History
Paris- France and six isolates were identified in the
College of Agriculture, Damascus University.
The ability of fungal isolates for secretion aflatoxins B1, B2 and G1 was
detected by thin layer chromatography technique and the quantity of toxins
was determined by using electronic scanner in Syrian Atomic Agency by
comparison with similar standard toxins.