title: Synthesis of ethyl isovalerate using Rhizomucor miehei lipase: optimization.
abstract: Immobilized lipase from Rhizomucor miehei (Lipozyme IM-20) was used to catalyze the esterification reaction between isovaleric acid and ethanol to synthesize ethyl isovalerate in n-hexane. Response surface methodology based on five-level four-variable central composite rotatable design was employed to optimize four important reaction variables such as enzyme/substrate E/S ratio, substrate concentration, incubation time, and temperature affecting the synthesis of ethyl isovalerate. The optimum conditions predicted for achieving maximum ester yield (500 mM) are as follows: E/S ratio, 48.41 g/mol; substrate concentration, 1 M; reaction time, 60 h; temperature, 60 degrees C. The predicted value matched well with experimentally obtained value of 487 mM.
authors.affiliation: Fermentation Technology and Bioengineering Department, Central Food Technological Research Institute, Mysore 570 013, India.
authors.forename: G V
authors.initials: GV
authors.lastname: Chowdary
authors.forename: S G
authors.initials: SG
authors.lastname: Prapulla
mesh_terms: D000704:Analysis of Variance; D002384:Catalysis; D004800:Enzymes, Immobilized; D004951:Esterification; D000431:Ethanol / Q000737:chemistry; D045782:Hemiterpenes; D006586:Hexanes; D008049:Lipase / Q000737:chemistry*; D008432:Mathematical Computing; D010421:Pentanoic Acids / Q000737:chemistry; D020103:Rhizomucor / Q000737:chemistry*; D013379:Substrate Specificity; D013696:Temperature; D013997:Time Factors; D014631:Valerates / Q000138:chemical synthesis*
chemical_list: D004800:Enzymes, Immobilized; D045782:Hemiterpenes; D006586:Hexanes; D010421:Pentanoic Acids; D014631:Valerates; C008216:isovaleric acid; D000431:Ethanol; C475857:ethyl isovalerate; D008049:Lipase