Author/Authors :
Mohammadi Farsani, Masoud Department of Biology - Faculty of Science - Shahid Chamran University of Ahvaz, Ahvaz, Iran , Mohammadi, Mohammad Department of Biology - Faculty of Science - Shahid Chamran University of Ahvaz, Ahvaz, Iran , Ghezelbash, Gholam Reza Department of Biology - Faculty of Science - Shahid Chamran University of Ahvaz, Ahvaz, Iran , Shahriari, Ali Department of Basic Sciences - Faculty of Veterinary Medicine - Shahid Chamran University of Ahvaz, Ahvaz, Iran
Abstract :
Erythritol as a non-caloric and non-cariogenic sweetener is safe for diabetics. Both microbial fermentation
and chemical methods can be used to produce erythritol, but chemical methods failed to be industrialized due to
their low efficiency. Moniliella tomentosa, Aureobasidium sp. and Yarrowia lipolytica are industrial producers of
erythritol. Erythrose reductase (ER) is a key enzyme in the biosynthesis of erythritol and catalyzes the final step in
this pathway. Enzyme extract was obtained from Y. lipolytica by grinding cells with 0.5mm glass beads and ER
activity was performed using 10 μl enzyme extract, 7.5 mM NADPH and 12 mM D-erythrose in potassium
phosphate buffer (pH 7.5). Reaction was monitored with decreasing of NADPH absorbance in OD340 at 37 ˚C for 8
min by a microplate analyzer. In order to determine the activation energy (Ea), activity of enzyme was measured in
4-45 ˚C and results were analyzed with Kinetic software according to Arrhenius equation. The best enzyme activity
of ER was 6.268 mU. One unit of ER activity was defined as the amount of enzyme that catalyzes the oxidation of
1μmol of NADPH per minute. Specific activity of enzyme was equal to 3.24U/mg and finally the Ea was
determined to be 29.6208 KJ.ER specific activity in this study was lower than the only similar study that used Y.
lipolytica. Purification, overexpression and optimizing the reaction can help to increase enzyme performance.
