Title : Whole-cell bioconversion of naringenin using Yarrowia lipolytica 2.2ab in surface and liquid cultures
Abstract:
Naringenin is a polyphenolic molecule considered within the subgroup of flavanones that in addition to the important antioxidant activity, several beneficial effects on health have been attributed to this molecule. Flavonoids are natural phenolic compounds that exert several biological acivities suchlike antioxidant, antiinflammatory, antibacterial, antiviral, estrogenic, vasodilator, hepatoprotective, antihemorrhagic, and many others. Naringenin is a polyphenolic molecule considered within the subgroup of flavanones, which in addition to the important antioxidant activity, several beneficial effects on health have been attributed to this molecule. For this reason, the study of this molecule has attracted the attention of various research groups. The flavanones also called bioactive compounds, are plant origin and their industrial production is limited due to their complex extraction from vegetal substrates and the low extraction obtained. To overcome these limitations, the microbial biosynthesis may represent a suitable alternative to increase its production. The antioxidant activity exerted by the flavonoids is related to the hydroxyl groups in the polyphenol B ring, reason why the increase of the antioxidant activity in the flavonoids is directly related to the hydroxylation degree. The increase in the hydroxylation degree of the flavonoid molecules can be directed from specific molecules by means of its bioconversion by enzymes or whole microbial cells. This study aims to identify the resulted products from naringenin bioconversion by whole cells of Yarrowia lipolytica 2.2ab (Yl2.2ab) either superficial and liquid culture media. Identification of the hydroxylated products was performed by HPLC and HPLC-MS-MS. Antioxidant activity was measured by ABTS and DPPH methods. Increase on hydroxylated and dehydrogenated groups from naringenin bioconversion by Yl2.2ab was observed in both culture media; apigenin, luteolin, aromadrine, ampelopsin and myricetin compounds were identified. These molecules are highly desired by the pharmaceutical and food industries; then are considered as compounds with high value added. Additionally, the compounds obtained have greater antioxidant activity with respect to naringenin, the molecule used as precursors during bioconversion by complete cells of Yl2.2ab shown in this work.
Audience Take Away:
- The audience will learn that the biological properties of flavonoids with important beneficial effects on human health might be enhanced by increasing the adding more hydroxylated and / or methoxylated groups of an original precursor. They will also learn that bioconversion processes consist of enzymatic modifications to a given substrate by biological systems (microbial whole cells) as biocatalysts.
- The industrial production of flavonoids is restricted due to low concentrations in plant tissues, low presence in species, and difficulties find during its extraction from plants. To overcome these restrictions a promising strategy is the bioconversion mechanism. In this study, the biological properties of the flavonoids are analyzed focusing on the relationship between their antioxidant activity and the degree of hydroxylation which occur through alternative processes such as microbial bioconversion, obtaining compounds with greater added value.
- This simple process of microbial bioconversion for the efficient production of polyhydroxylated compounds from naringenin by yeast Y. lipolytica 2.2ab gives rise to future research projects where this type of process is carried out with whole cells and bioactive compounds serving as a direct antecedent and as a basis for an optimization of the process.
- Because this process of bioconversion is simple it represents a practical and efficient solution in the obtaining of compounds of interest.
- The bioconversion process can be optimized to provide new information, selection of the appropriate bioreactor and obtain better production.
