Valorisation des huiles végétales d’origine béninoise par alcoolyse enzymatique

Abstract

Fatty acid esters synthesized from vegetable oils by alcoholysis reaction are potentially applied in cosmetic and as biodiesel fuel. The alcoholysis of cottonseed oil by lipases from various microorganisms was investigated. Among several microbial lipases tested in this work, some strains showed high hydrolytic activity, allowing activity for alcoholysis reaction. To select suitable alcohols and biocatalysts, alcoholysis screening in n-hexane and in a solvent free medium was developed. In organic solvent, only crude lipases from Pseudomonas strain were active in all alcohol tested. The best conversion (93%) was found with Pseudomonas fluorescens lipase (AK). In a solvent free medium, except Pseudomonas strain lipase, all crude microbial lipases were almost inactivated. To solve such lipase inhibition, a three step protocol addition of methanol was used. By using this enzymatic process, Pseudomonas fluorescens lipase immobilized on polypropylene support displayed high conversion (> 61%) in various beninese vegetable oils. Thus, giving added value to cheaper vegetable oils.

Keywords

• alcoholysis reaction
• lipases
• immobilization
• natural vegetable oils
• organic solvent
• fatty acid esters