SELECTION OF OPTIMAL CONDITIONS FOR OBTAINING A LIPOLYTIC ENZYME FROM THE SEEDS OF Nigella sativa T.A. Khudoiberdiev, Sh.Sh. Shomakhamatov, Yu.I. Oshchepkova Institute of Bioorganic Chemistry named after A.S. Sаdykov of the Academy of Sciences of Uzbekistan, Republic of Uzbekistan At present, the use of low-waste technologies, increasing their growth and increasing
the cost of phytopreparations is becoming more and more relevant for pharmaceutical
production. It is possible to achieve this goal by taking into account additional
biological groups and possibilities of medical preparations application.
Along with
other entered into practice microbial, plant and animal proteases, amylases, pectinases,
lipolytic enzymes are widely used.
Lipolytic enzymes (lipases) are a group of enzymes that catalyze the reactions of
hydrolytic cleavage of fats with the formation of mono- and diglycerides and free fatty
acids, with the greatest affinity of the enzyme to the ester bonds located on the outer
part of the triglyceride molecule. The seeds of
Nigella sativa , family
Rananculaceae , in
addition to valuable oil containing a complex of active substances and antimicrobial
peptides, also contain a lipolytic enzyme.
After degreasing the crushed seeds of
Nigella sativa , the isolation of lipolytic
enzyme was carried out. During the isolation, physicochemical properties such as the
effect of pH and temperature on the stability of the enzyme were studied. To determine
the pH optimum of lipolytic enzyme extraction was carried out with water in the pH
range of 8-12, since in the range of these values the lipolytic activity of the enzyme is
110-115 thousand units/g, with the optimum at pH 10-11 (140-150 thousand units/g).
For research, the pre-crushed seeds were degreased over hexane in a Soxhlet
apparatus for 72 hours. The meal was dried and 13 g portions were prepared for the
experiments.
During the studies, the activation time was varied in the range from 6 to 24 hours. To
determine the optimum activation temperature, activation was carried out in the range of
35
0
C - 40
0
C. It is known that the dependence of lipolytic activity on temperature is
explained by the fact that, on the one hand, this factor affects the protein part of the
enzyme, leading to its denaturation and a decrease in the level of activity, on the other
hand, the increase in temperature increases the reaction rate of formation of the enzyme-
substrate complex.
From the obtained results, it was determined that the pH optimum for the extraction
of the studied lipolytic enzyme is in the range 10.5±0.02 - 11.0±0.01, and the highest
yield of the target product is observed at pH = 10.5, when activated 37 degrees for 24
hours was 0.45 g (3.46% of the feedstock). The yield of the target product decreases
with increasing activation time. In this regard, we can conclude that the most optimal
activation time is 24 hours.