Bacteria Help Create Tropical Grass' Pleasant Aroma

Vetiver is the only grass cultivated for the essential oil produced by its roots. It turns out that bacteria within the plant roots are responsible for producing many of the compounds that give the tropical plant's essential oil—used in perfumes and cosmetics—its earthy, woody, and slightly sweet aroma, a team of Italian scientists reports (Environ. Microbiol. 2008, 10, 2824).

Previous research had shown that vetiver raised under sterile conditions isn't able to create the complex essential oil. Pietro Alifano of the University of Salento, in Lecce; Massimo E. Maffei of the University of Turin; and colleagues found that microbes metabolize sesquiterpenes produced by the plant to create the array of compounds, including β-bourbonene and δ-cadinene, that make up the oil.

The researchers say the results show that bacteria can play a role in essential-oil biosynthesis and could conceivably be manipulated to alter the content of plant oils. Pharmaceutical, perfume, and flavor manufacturers could find this flexibility useful for producing novel compounds.