<i>De Novo</i> Production of Xanthohumol by a Metabolically Engineered <i>Escherichia coli</i>

Xanthohumol is a prenylflavonoid from hops with relevant bioactivities. Microbial production has emerged as a sustainable and potentially economic solution to produce it. Herein, we constructed a pathway for the <i>de novo</i> production of xanthohumol in <i>Escherichia coli</i>. Since the xanthohumol pathway depends on the availability of dimethylallyl pyrophosphate (DMAPP) and <i>S-</i>adenosylmethionine (SAM), SAM synthase (<i>metK</i>) was integrated into the genome of <i>E. coli</i> strains with previously engineered DMAPP pathways. Eleven prenyltransferases (PT) and the <i>O</i>-methyltransferase (OMT) from <i>Humulus lupulus</i> (<i>Hl</i>OMT1) were tested. <i>E. coli</i> M-PAR-121:<i>Bl</i>IDI:<i>metK</i>, constructed by integrating <i>metK</i> into the <i>E. coli</i> strain with integration of isopentenyl diphosphate isomerase (IDI) from <i>Bacillus licheniformis</i> (<i>E. coli</i> M-PAR-121:<i>Bl</i>IDI) and expressing CdpC3PT from <i>Neosartorya fischeri</i> and <i>Hl</i>OMT1 in combination with the naringenin chalcone pathway, was the best producer. This strain was able to produce 7.3 mg/L of desmethylxanthohumol and 5.3 mg/L of xanthohumol in the bioreactor, representing the first report of <i>de novo</i> production of xanthohumol in <i>E. coli</i>.