Metabolic engineering of Escherichia coli for the production of isoflavonoid ‐4′‐O‐methoxides and their biological activities

AbstractIsoflavonoid representatives such as genistein and daidzein are highly potent anticancer, antibacterial, and antioxidant agents. It have been demonstrated that methylation of flavonoids enhanced the transporting ability, which lead to facilitated absorption and greatly increased bioavailability. In this paper, genetically engineeredEscherichia coli was reconstructed by harboringE. coli K12 ‐derivedmetK encodingS‐adenosine‐l‐methionine (SAM) synthase (accession number: K02129) for enhancement of SAM as a precursor andStreptomyces avermitilis originatedSaOMT2 (O‐methyltransferase, accession number: NP_823558) for methylation of daidzein and genistein as preferred substrates. The formation of desired products via biotransformation including 4′‐O‐methyl‐genistein and 4′‐O‐methyl‐daidzein was confirmed individually by using chromatographical methods such as high‐performance liquid chromatography, liquid chromatography/time‐of‐flight/mass spectrometry (LC‐TOF‐MS), and nuclear magnetic resonance (NMR), and NMR (1H and13C). Furthermore, substrates concentration, incubation time, and media parameters were optimized using flask culture. Finally, the most fit conditions were applied for fed ‐batch fermentation with scale‐up to 3 L (working volume) to obtain the maximum yield of the products including 164.25 µM (46.81 mg/L) and 382.50 µM (102.88 mg/L) for 4′‐O‐methyl genistein and 4′‐O‐methyl daidzein, respectively. In pa...
Source: Biotechnology and Applied Biochemistry - Category: Biochemistry Authors: Tags: Original Article Source Type: research