EXTRACTION OF LACTATE DEHYDROGENASE (LDH) FROM RICE FOR THE CONVERSION OF PYRUVIC ACID INTO LACTIC ACID

• Main Author: Alif Akbar Syach, Muhammad
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/65853
• Institution: Institut Teknologi Bandung

Lactic acid is a compound that is often encountered in various industries because it can be converted into a variety of high-value chemicals. Most of the lactic acid in the industry is still produced using chemical catalysts where the operating conditions are relatively high, the availability of raw materials is not sustainable, and the raw material costs are relatively expensive. The enzymatic pathway is expected to be an alternative conversion pathway because of its relatively easy operating conditions and the availability of sustainable raw materials. Biochemically, the conversion of glycerol into lactic acid is possible by first converting glycerol into pyruvic acid. Then, pyruvic acid is converted to lactic acid using the enzyme lactate dehydrogenase (LDH). It is known that this LDH enzyme is found in rice seeds (Oryza sativa). This research was conducted to determine the potential of the LDH enzyme in rice extract to convert pyruvic acid to lactic acid. In this study, the extraction of LDH from rice seeds with variations in extraction temperature was carried out and analyzed by the Bradford test. In this experiment, the highest protein concentration obtained by varying extraction temperature is 30,73 g/L at 5°C. In addition, variations were also carried out on the conversion reaction process of pyruvic acid to lactic acid using crude rice extract. The reaction products were analyzed by High Performance Liquid Chromatography (HPLC). In this experiment, variations in reaction temperature produced the highest concentration at 57°C (1,12 g/L). Meanwhile, the variation of crude rice extract content yields the highest concentration at 40%-v/v (0.53 g/L). These results indicate the presence of LDH enzyme in the crude rice extract which has the potential to convert pyruvic acid to lactic acid although the amount is still very small because there are other compounds with high concentration in the reaction product. There is a need to identify these dominant compounds in the reaction and the addition of more