Biotransformation Of Terpenes Research Articles

Biotransformation of Volatiles in Fermented Osmanthus (Osmanthus fragrans) Flowers by Yeast

Sweet osmanthus (Osmanthus fragrans) is a species of flowering plants in Asia prized for food, flavor and fragrance industries. This work studied biotransformation of volatiles in osmanthus flowers through monoculture fermentation of infusions of sweet osmanthus flowers using yeasts, Saccharomyces cerevisiae and Williopsis saturnus. The major volatiles in two osmanthus cultivars Jingui and Yingui before and after fermentation were terpenoids and ketones. Esters, alcohols and acetic acid were only present after fermentation, and aldehydes were largely depleted after fermentation. The volatile profile of sweet osmanthus flowers fermented with S. cerevisiae was described as sweet and floral, while that of sweet osmanthus flowers fermented with W. saturnus was fruity, sweet and floral. Addition of nutrients (glucose and diammonium phosphate) increased alcohol and ester production, decreased percentage reduction of ketones and terpenes. Biotransformation of terpenes varied with each compound and fermentation treatment. Overall, yeast fermentation proved to be effective in enhancing sweet osmanthus flower fragrance for production of unique essential oils from this invaluable flower.

Biotransformation of limonene by an endophytic fungus using synthetic and orange residue-based media

Aroma and fragrances have high commercial value for use in food, cosmetics and perfumes. The biotransformation of terpenes by microorganisms represents an attractive alternative method for production of flavourings. Endophytic fungi offer a great potential for the production of several groups of compounds; however, few studies have evaluated the biotransformation of limonene. Following preliminary studies on the biotransformation of limonene, submerged fermentation was carried out using an endophytic fungus isolated from Pinus taeda and identified as Phomopsis sp. The presence of several biotransformation products was detected and identified by mass spectrometry (GC–MS). The studied strain showed a divergent metabolic behaviour, as compounds of interest such as α-terpineol, carvone, and limoneno-1,2-diol were produced under different conditions. In addition to the minor metabolites terpinen-4-ol, menthol and carveol, this strain also produced major metabolites, including 0.536 g L−1 carvone and 2.08 g L−1 limonene-1,2-diol in synthetic medium and 2.10 g L−1 limonene-1,2-diol in a natural orange extract medium with single fed-batch, while the cyclic fed-batch resulted in concentrations less than 1 g L−1. Therefore, our study produced a wide variety of limonene derivatives at a high concentration using a natural medium and a newly isolated endophytic fungal strain.

An In Vivo Assay for Elucidating the Importance of Cytochromes P450 for the Ability of a Wild Mammalian Herbivore (Neotoma lepida) to Consume Toxic Plants

An in vivo assay using the cytochrome P450 (P450) suicide inhibitor 1-aminobenzotriazole (ABT) and 24-h food intake was developed to determine the relative importance of P450s in two populations of Neotoma lepida with respect to biotransformation of plant secondary compounds in the animals' natural diets. The efficacy of ABT as a P450 inhibitor was first validated using hypnotic-state assays with and without pretreatment with ABT. Pretreatment with 100 mg/kg ABT by gavage increased hexobarbital sleep times 3-4-fold in both populations, showing effective inhibition of P450s in woodrats. Next, the Great Basin population was fed a terpene-rich juniper diet, and the Mojave population was fed a phenolic-rich creosote diet, with rabbit chow serving as the control diet in each group. Treatment with ABT inhibited food intake in the Great Basin population fed the juniper diet to a greater extent (35%) than the Great Basin population fed the control diet (19%) or the Mojave population fed the creosote diet (16%). The food intake of the Mojave population fed the control diet was not significantly inhibited by ABT. The findings suggest that the biotransformation of terpenes in juniper relies more heavily on P450s than that of phenolics in creosote. This assay provides an inexpensive and noninvasive method to explore the relative importance of P450s in the biotransformation strategies of wild mammalian herbivores.

Application of fungal endophytes in biotechnological processes

The term “endophytes” includes a family of microorganisms that grow intra-and/or intercelullarly in the tissues of higher plants without causing over symptoms on the plants in which they live. These microorganisms represent a potential source of novel natural products for medicinal, agricultural and industrial uses, such as antibiotics, anticancer agents, biological control agents, and other bioactive compounds. The aim of the present work was to investigate the biotechnological potential of fungal endophytes isolated from Baru (Dipteryx alata Vog.). Accordingly, the antimicrobial activity, the enzymatic profile and the biotransformation of terpenes in aroma compounds were evaluated. A total of 5 fungal strains were isolated from Baru and identified in the present work. Screening of the antimicrobial activity of endophytic extracts revealed a considerable activity against the pathogenic cultures tested. Most of the extracts inhibited the growth of Candida albicans, Escherichia coli and Sthaphylococcus aureus. Meanwhile, the production of proteases was not detected, however all showed potential of amylase and lipase production. The preliminary results obtained from the biotransformation process showed that three fungal strains bioconverted α-pinene into verbenol (85 % similarity in MS results), compound with great industrial interest. The use of endophytic microorganisms isolated from Brazilian biome demonstrates their potential for application in biotechnological processes.

Biotransformation of terpenes and related compounds by suspension culture ofGlycyrrhiza glabra L. (Papilionaceae)

Biotransformation of monoterpene aldehydes and related compounds, carvone and bornyl acetate was carried out by cell suspension culture of Glycyrrhiza glabra L. Cells reduced most saturated and unsaturated terpene aldehydes, aromatic and related aldehydes to corresponding primary alcohols. Furthermore, the C=C bonds in the side chain of cinnamaldehyde and in the cyclohexene ring of carvone were converted into corresponding saturated compounds, hydrocinnamylalcohol, cis- and trans-dihydrocarvone. Bornyl acetate hydrolyzed to two isomers, isoborneol and endo-borneol. Copyright © 2004 John Wiley & Sons, Ltd.

Biotransformation of terpenes from Stemodia maritima by Aspergillus niger ATCC 9142

Incubation of stemodin ( 1) in cultures of Aspergillus niger ATCC 9142 resulted in the production of 2α,3β,13-trihydroxystemodane ( 2), 2α,7β,13-trihydroxystemodane ( 3) and 2α,13,16β-trihydroxystemodane ( 4), while stemodinone ( 5) afforded 13,18-dihydroxystemodan-2-one ( 6) and 13,16β-dihydroxystemodan-2-one ( 7). Four novel metabolites were obtained from the bioconversion of stemarin ( 8) by the fungus, namely 18-hydroxystemaran-19-oic acid ( 9), 7β,18-dihydroxystemaran-19-oic acid ( 10), 7α,18,19-trihydroxystemarane ( 11) and 1β-hydroxystemaran-19-oic acid ( 12). 19- N,N-Dimethylcarbamoxy-13-hydroxystemarane ( 13) was also transformed to afford 19- N,N-dimethylcarbamoxy-13,17ξ,18-trihydroxystemarane ( 14).

Biotransformation of terpenes by fungi: Study of the pathways involved

The biotransformation of the pure terpene alcohols geraniol and nerol, the mixture of the alcohols, ‘citrol’, and the mixture of the aldehydes, citral, to 6-methyl-5-hepten-2-one by sporulated surface cultures of Penicilliumdigitatum was compared. It was found that citral was converted faster than the alcohols but gave a lower overall yield of ≈76%, whereas the pure alcohols and their mixture, ‘citrol’, gave a yield of ≈83%. It was also established that the bioconversion over prolonged periods was possible with an overall yield of 80–90% depending on the substrate used. The bioconversion of nerol to 6-methyl-5-hepten-2-one by a spore suspension was also shown. The pathways involved in the biotransformation of geraniol and citral to 6-methyl-5-hepten-2-one are also discussed.

Enhanced biotransformation of terpenes in plant cell suspensions using controlled release polymer

Plant cell cultures of Peganum harmala converted geranyl acetate to geraniol. Although the reaction started immediately after feeding, there was disappearance of both product and substrate. Geranyl acetate at 100 mg l−1 when fed to 100 ml Peganum harmala suspensions (16% packed cell volume) was completely used within 24 h without accumulation of any product. Similarly, linalyl acetate and its biotransformation products, linalool and α-terpineol, disappeared. Controlled-release polymer discs made from poly-2-hydroxyethyl methacrylate and containing concentrations of geranyl acetate or linalyl acetate produced greatly extended concentrations of these substrates and their biotransformation products (from about 1 day to over 12 days). The concentrations of substrates remained at around 5 mg l−1throughout the experiments, while the concentrations of biotransformation products increased from 10 mg l−1to 55.5 mg l−1 for geraniol, from 5 mg l−1 to 14 mg l−1 for linalool, and 5 mg l−1 to 12 mg l−1 for α-terpineol compared to the control value. Also low concentrations (30–200 μg/disc) of product were taken up by the polymer over 10 days.