Preliminary comparison of vetiver root essential oils from cleansed (bacteria- and fungus-free) versus non-cleansed (normal) vetiver plants

The 'Sunshine' cultivar of vetiver (Vetiveria zizanioides (L.) Nash, = Chrysopogon ZiZanioides (L.) Roberty) was subjected to meristerm tissue culture in order to produce plants that were bacteria- and fungi-free. Tissue cultured ("cleansed" or phytosanitary) vetiver was grown for five months in pots of sterilized soil, and the oil compared to non-cleansed (normal) vetiver plants grown in the same conditions except using pots of unsterilized soil. The steam distilled (24 h) oil of the roots from tissue cultured (cleansed) vetiver yielded 0.02% clear oil compared to a 0.35% yield of light yellow oil for the normal vetiver plants, a 17-fold smaller yield. GC/MS analyses of the oils revealed that the non-cleansed (normal) vetiver had the typical vetiver oil profile, whereas the tissue cultured (cleansed) vetiver produced large amounts Of C-19-C-29 alkanes plus several alkanols along with typical vetiver oil compounds, but lacked presumed fungal metabolites such as beta-funebrene, prezizaene, alpha-amorphene, and beta-vetispirene. An unidentified biotic factor (apparently bacteria or fungi) appears to enhance the oil production in normal vetiver by both increasing yield and by the generation of signature oil compounds. These preliminary results of endogenous microbial transformations of plant chemistry may have broader physiological implications, especially among monocotyledons (including cereals). (C) 2004 Elsevier Ltd. All rights reserved.