Characterization of bacterial transporters involved in the uptake of lignin-derived aromatic compounds.

Abstract

Chemically depolymerized low-molecular-weight lignin can be converted into polymer building blocks using bacterial convergent metabolic systems called biological funneling. Various bacterial enzyme genes involved in the catabolism of lignin-derived aromatic compounds have been identified and characterized in detail. This information is essential for developing the bioproduction of high-value-added chemicals from lignin. Transporters responsible for the first step in catabolism mediate the transport of substrates across biological membranes. Since substrate uptake in biological membranes can be an obstacle or a rate-limiting process in the bacterial production of value-added compounds, it is vital to understand not only enzyme functions but also uptake systems. In this chapter, we focus on the bacterial transporters for lignin-derived aromatic compounds that have been reported and introduce methods for the characterization of transporters, primarily through in vivo analyses. In addition, we will present an antibody-based analysis of the cellular localization of transporters.