DdvK, a Novel Major Facilitator Superfamily Transporter Essential for 5,5′-Dehydrodivanillate Uptake by Sphingobium sp. Strain SYK-6

The bioengineering of bacteria to selectively transport and metabolize natural substrates into specific metabolites is a valuable strategy for industrial-scale chemical production. The uptake of many substrates into cells requires specific transport systems, and so the identification and characterization of transporter genes are essential for industrial applications. A number of bacterial major facilitator superfamily transporters of aromatic acids have been identified and characterized, but many transporters of lignin-derived aromatic acids remain unidentified. The efficient conversion of lignin, an abundant but unutilized aromatic biomass resource, to value-added metabolites using microbial catabolism requires the characterization of transporters for lignin-derived aromatics. In this study, we identified the transporter gene responsible for the uptake of 5,5′-dehydrodivanillate, a lignin-derived biphenyl compound, inSphingobium sp. strain SYK-6. In addition to characterizing its function, we applied this transporter gene to the production of a value-added metabolite from 5,5′-dehydrodivanillate.