Biotransformation of citral by botrytis cinerea

Abstract

Biotransformation of citral(1)was studied with four strains of Botrytis cinerea using grape must(A), a synthetic medium(B) and mixtures of A and B. Whereas in A complete metabolization of 1 without evidence of any volatile product was observed, in Bnerol (2) and geraniol (3) were found as predominant volatile bioconversion products; in minor amounts (£, Z)-2, 6-dim ethylocta-2,6 -dien-l,8-diol(4)and (£, E)-2,6-dimethylocta-2, 6-dien-l,8 -diol(5),2-methyl-2-hepten-6-one(6),2-m ethyl-2-hepten-6-ol(7),2-methyl-2-hepten-6-one-l-ol(8) and 2-methyl-y-butyrolactone(9) were identified. Using small amounts of A in B (1:700 to 5:700) low yields of 2 and 3 were obtained, whereas the quantities of 4,5,6 and 8 increased. Quantitatively, the results were strongly d ependent on the strains used. The bioconversion products were all identified by capillary gas chromatography (HRGC) and coupled HRGC techniques, i.e.-mass spectrom etry(HRGC-MS) and-Fourier transform infrared spectroscopy (HRGC-FTIR). © 1987, Walter de Gruyter. All rights reserved.