INITIAL STUDIES OF MICROBIAL PRODUCTION OF ISOPRENE

• Main Author: Amirah June, Rahmah
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/48549
• Institution: Institut Teknologi Bandung

Isoprene or 2-methyl-1,3-butadiene is C-5 hydrocarbon which being the monomer of terpenoids. Isoprene has an important role as raw material to produce synthetic rubber, adhesive, and used as an additive for gasoline, solar and avtur. Nowadays, the utilization of isoprene in industries still relies on petroleum as main raw material. In line with the increasing demand of isoprene, the availability of petroleum is threatened. Moreover, isoprene is produced by plants but unfeasible for commercial used owing to the difficulty of harvesting this volatile product, and isoprene has an important role in plant physiology. Related to these issues, renewable resources are urgently needed to replace petroleum and plants. The utilization of microbial metabolic pathways was studied further as a solution for these issues. Bacillus has great potential to produce isoprene through methylerythritol 4-phosphate (MEP) metabolic pathways. This research aims to study about isoprene production from Bacillus subtilis, B. amyloliquefaciens, and B. megaterium through a fermentation process. The study aims to get the optimum temperature for the growth of microbes and the isoprene production. This study chooses Luria-Bertani as medium fermentation with temperature processes are 37ºC, 45ºC, and 52ºC. The fermentation was in aerobic condition, the oxygen rate was 3,5L/min. This study used spectrophotometer to examine concentration cell of biomass. The optimum temperatures for growth and isoprene production for each B. subtilis, B. megaterium, and B. amyloliquefaciens are 52ºC, 45ºC, and 37ºC. These conditions can produce higher cells and have a rapid growth rate. Based on the results of Monod modeling, the substrate utilization constant (Ks) of glucose is 1.3 mg/L and the maximum specific growth rate is 0.42 h-1. Estimates of isoprene concentration for each B. subtilis, B. megaterium, and B. amyloliquefaciens are 1.035x10-10 g/ml; 1.904x10-10 g/ml; and 2.074x10-10 g/ml. Thus, B. amyloliquefaciens has great potential for isoprene production.