Microbial transformation of limonene

Limonene (92) is the most widely distributed terpene in nature after a-pinene [68]. The (+)-isomer is present in Citrus peel oils at a concentration of over 90% a low concentration of the (-)-isomer is found in oils from the Mentha species and conifers [26]. The first data on the microbial transformation of limonene date back to the sixties. A soil Pseudomonad was isolated by enrichment culture technique on limonene as the sole source of carbon [69]. This Pseudomonad was also capable of growing on a-pinene, / -pinene, 1-p-menthene and p-cymene. The optimal level of limonene for growth was 0.3-0.6% (v/v) although no toxicity was observed at 2% levels. Fermentation of limonene by this bacterium in a mineral-salts medium resulted in the formation of a large number of neutral and acidic products. Dihydrocarvone, carvone, carveol, 8-p-menthene-1,2-cw-diol, 8-p-menthen-1 -ol-2-one, 8-p-menthene-1,2-trans-diol and 1 -p-menthene-6,9-diol were among the neutral products isolated and identified. The acidic compounds isolated and identified were perillic acid, /Msopropenyl pimelic acid, 2-hydroxy-8-p-menthen-7-oic acid and... 

FIGURE 19.35 Biotransformation of (-)-limonene (68 ) by citrus pathogenic fungi, Penicillium digitatum (Pers. Fr.) Sacc. KCPYN. (Modi ed from Noma, Y. and Asakawa, Y Microbial transformation of limonene and related compounds, Proceedings of 51st TEAC, 2007b, pp. 299-301.)... 

Bowen, E.R., 1975. Potential by-products from microbial transformation of [Pg.896]

Noma, Y. and Y. T akawa, 2007b. Microbial transformation of limonene and related compounds. Proceedings of the 51st TEAC, pp. 299 301. 

The main products of limonene oxidation, carvone and carveol, cause a terpenic off-flavour in essential oils and juices. Valencene oxidation products, such as (-F)-nootkatone, cause a grapefruit-like off-flavour in orange juices. Large amounts of alcohol (-F)-o(-terpineol, which arises, for example, during storing of juices by acid catalysed hydration or microbial transformation of limonene, is also perceived as an off-flavour. 

Rama-Devi, J. and Battacharyya, P.K. 1977. Microbial transformation of terpenes Part XXIV. Pathways of degradation of geraniol, nerol and limonene by Pseudomonas incognita (linalool strain). Indian J. Biochem. Biophys. 14 359-363. 

The production of glycols from limonene (68) and other terpenes with a 1-menthene skeleton was reported by Corynespora cassiicola DSM 62475 and D. gossypina ATCC 10936 (Abraham et al., 1984). Accumulation of glycols during fermentation was observed. An extensive overview on the microbial transformations of terpenoids with a 1-p-menthene skeleton was published by Abraham et al. (1986). 

Dhavalikar, R.S. and P.K. Bhattacharyya, 1966. Microbial transformation of terpenes. Part VIII. Fermentation of limonene by a soil Pseudomonad. Indian J. Biochem., 3 144-157. 

Saeki, M. and N. Hashimoto, 1968. Microbial transformation of terpene hydrocarbons. Part I. Oxidation products of li limonene and [Pg.904]

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