SCREENING OF LOCCAL LIPASE ISOLATES FROM PSEUDOMONAS STUTZERI AND GEOBACILLUS THERMOLEOVORANS FOR THE MANUFACTURE OF BIOLUBRICANT

• Main Author: Khoirunnisa', Zulfa
• Format: Final Project
• Language: Indonesia
• Subjects: Kimia
• Online Access: https://digilib.itb.ac.id/gdl/view/79571
• Institution: Institut Teknologi Bandung

Each lipase LK2 and PPD have good hydrolysis and transesterification activities as biocatalysts in synthesis biodiesel. The research aims to determine the lipase transesterification activity of local isolates using experimental and biocomputational approaches for synthesis biolubricant. Lipase transesterification activity was tested by synthesizing pNP esters using methyl laurate as a substrate in acetone solvent. Reaction transesterification was carried out at a shaking speed of 120 rpm, temperature 50 °C for 6 hours. The progress of the reaction was analyzed by looking at changes in the concentration of the pNP substrate with UV-VIS spectrophotometer at 400 nm. The crude extract resulting from sonication-lysozyme lysis had the highest transesterification activity of the LK2 enzyme at 1,578 0,013 U/mg, compared to the PPD transesterification activity of 1,100 0,007 U/mg. The same results were also seen in the crude extract resulting from SDS-boiling lysis. The transesterfication activity of LK2 crude extract was 1,287 0,027 U/mg, while PPD was 0,936 0,001 U/mg. Bioubricant synthesis was carried out using the reflux method. The results of thin layer chromatography showed that the local isolate lipase LK2 gave a light stain, while PPD did not show a stain. The protein-ligand docking process is carried out to see the interaction between the receptor and the ligand during a catalysis reaction using the AutodockVina application. The LK2 enzyme has hydrogen interactions between oxygen substrate carbonyl with the carbonyl oxygen atom at residue S109. The PPD enzyme has a hydrogen interaction between the ester oxygen atom on the substrate and the hydrogen atom in the imidazole group of residue H387. Bioinformatics studies using the CASTp server show that LK2 has an area of 543,362 Å2 and a catalytic pocket volume of 640,821 Å3, while PPD has an area of 173,333 Å2 and a catalytic pocket volume of 142,587 Å3. With these results, the transesterification activity of the LK2 and PPD enzymes has been confirmed biocomputationally.