Optimising the synthesis of isoamyl butyrate using Rhizopus sp. lipase with a central composite rotatable design

• Published in: Process biochemistry (1991) Vol. 39; no. 6; pp. 687 - 693
• Main Authors: Macedo, G.A, Pastore, G.M, Rodrigues, M.I
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 25-02-2004
• Subjects: Central composite rotatable design (CCRD); Enzymic synthesis; Esterification; Geotrichum sp. lipase; Isoamyl butyrate, Rhizopus sp. lipase; Response surface methodology (RSM); Central composite rotatable design (CCRD); Isoamyl butyrate, Rhizopus sp. lipase; Geotrichum sp. lipase; Enzymic synthesis; Response surface methodology (RSM); Esterification
• ISSN: 1359-5113; 1873-3298
• DOI: 10.1016/S0032-9592(03)00153-5

Microbial lipases (E.C. 3.1.1.3) produced by
Geotrichum sp. and
Rhizopus sp. were prepared and tested as catalysts in the esterification of isoamyl alcohol and butyric acid in a solvent-free system. Response surface methodology (RSM) based on a five-level, two-variable central composite rotatable design (CCRD) was used to optimise this process, with respect to important reaction variables-substrate molar ratio (RM), temperature and lipase concentration (L). The variables RM and L were the most significant in the process. An increase in alcohol concentration from 1:2 to 4:1 caused a decrease in yield to 18.45%, after 48 h of reaction time, and a variation of L from 1 to 10% caused an increase in yield to 32.2%. The optimum conditions found to achieve maximum ester yield (75%) are: RM=1.5:1; L=5.5% (w/w), 40
°C, after 48 h of reaction time.