Production of aromas and fragrances through microbial oxidation of monoterpenes

Abstract

-Aromas and fragrances can be obtained through the microbial oxidation of monoterpenes. Many microorganisms can be used to carry out extremely specific conversions using substrates of low commercial value. However, for many species, these substrates are highly toxic, consequently inhibiting their metabolism. In this work, the conversion ability of Aspergillus niger IOC-3913 for terpenic compounds was examined. This species was preselected because of its high resistance to toxic monoterpenic substrates. Though it has been grown in media containing R-limonene (one of the cheapest monoterpenic hydrocarbons, which is widely available on the market), the species has not shown the ability to metabolize it, since biotransformation products were not detected in high resolution gas chromatography analyses. For this reason, other monoterpenes (alpha-pinene, beta-pinene and camphor) were used as substrates. These compounds were shown to be metabolized by the selected strain, producing oxidized compounds. Four reaction systems were used: a) biotransformation in a liquid medium with cells in growth b) with pre-grown cultures c) with cells immobilized in a synthetic polymer network and d) in a solid medium to which the substrate was added via the gas phase. The main biotransformation products were found in all the reaction systems, although the adoption of previously cultivated cells seemed to favor biotransformation. Cell immobilization seemed to be a feasible strategy for alleviating the toxic effect of the substrate. Through mass spectrometry it was possible to identify verbenone and alpha-terpineol as the biotransformation products of alpha-pinene and beta-pinene, respectively. The structures of the other oxidation products are described.

Biotransformation of α-Pinene to Terpineol by Resting Cell Suspension of Absidia corulea

“…Where as biotransformation of (-)-a-Pinene produced 28.146 ± 0.65 mg of a-Terpineol and 9.774 ± 1.44 mg of isoterpineol at the end of 72 h. The results obtained in this work indicate that the enzymes responsible for the biotransformation producing the metabolites found in all the reaction systems studied are probably not having stereoselectivity, since the bioconversions of both the substrates resulted in the production of same compounds. Aspergillus niger selectively transformed a-pinene to verbenone, verbenol and a-terpineol whereas b-pinene to only a-terpineol [12,13]. The biotransformation of (-)-a-Pinene and (?…”

Interfaces com a indústria

“…Nossos primeiros resultados mostraram que alfa-e beta-pineno eram passíveis de oxidação microbiológica (Figura 19), o que não acontecia com limoneno 59,60 . Este estudo que prossegue hoje na URI-Erechim 61 , foi parcialmente financiado pelo Programa PROCAD/CAPES e demonstrou ser possível a produção de alfaterpineol 62,63 (Figura 20).…”

Enantioselectivity of hydroxylation of racemic piperitone by fungi

“…2,3,[5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23] The substrates and products of these transformations are components of many essential oils of plants, and they are also important for flavor and fragrance industry. 2,3,19,24 Hydroxylation at allylic position of a,b-unsaturated monoterpene ketones by microorganisms 15,16,20,22,23 and plant cell cultures [12][13][14]18 has been well documented. Piperitone, a monoterpene ketone, is the major constituent of essential oils from some Eucalyptus, Mentha, and Cymbopogon species.…”