Optimization of R-(+)-alpha-terpineol production by the biotransformation of R-(+)-limonene.
R-(+)-limonene is an abundant and non-expensive by-product of the citrus industry and is, therefore, a suitable starting material for the production of natural flavor and fragrance compounds. The biotransformation of R-(+)-limonene to R-(+)-alpha-terpineol by Fusarium oxysporum 152b has already been reported, although the influence of the main process parameters on the production has not yet been evaluated. In this paper, a Plackett-Burman screening design was used to define the effects of the medium composition (glucose, peptone, yeast extract, malt extract and pH), the presence of a co-substrate (biosurfactant), the cultivation conditions (temperature, agitation), the substrate concentration and the inoculum/culture medium ratio on the absolute amount of R-(+)-alpha-terpineol resulting from this biotransformation. The process conditions were further optimized applying response surface methodology (RSM). The volatiles were extracted using a SPME device and were subsequently quantified by GC-FID and identified by GC-MS. The best results were obtained using 0.5% (v/m) R-(+)-limonene in pure distilled water as the culture medium with an inoculum/culture medium ratio of 0.25 (m/m) and 72 h cultivation at 26 degrees C/240 rpm. Under these conditions the concentration of R-(+)-alpha-terpineol in the culture medium reached 2.4 g L(-1), a production almost six times greater than in earlier trials. The presence of a biosurfactant (0-500 mg L(-1)) did not significantly increase the yield.
Laboratório de Bioaromas, Departamento de Ciência de Alimentos - FEA, Universidade Estadual de Campinas, Rua Monteiro Lobato, 80. Cx. Postal 6121, Campinas, SP, 13083-862, Brazil, juliano@fea.unicamp.br.
Juliano Lemos
JL
Bicas
Francisco Fábio Cavalcante
FF
Barros
Roger
R
Wagner
Helena Teixeira
HT
Godoy
Gláucia Maria
GM
Pastore
D000704:Analysis of Variance; D001711:Biotransformation; D003470:Culture Media; D000081005:Cyclohexane Monoterpenes; D053138:Cyclohexenes / Q000138:chemical synthesis* / Q000378:metabolism*; D005524:Food Technology; D005670:Fusarium / Q000378:metabolism*; D016018:Least-Squares Analysis; D000077222:Limonene; D039821:Monoterpenes / Q000138:chemical synthesis*; D013696:Temperature; D013729:Terpenes / Q000378:metabolism*
D003470:Culture Media; D000081005:Cyclohexane Monoterpenes; D053138:Cyclohexenes; D039821:Monoterpenes; D013729:Terpenes; C016775:alpha-terpineol; D000077222:Limonene