Xanthomonas albilineans is a xylem-invading plant pathogen that causes leaf scald disease of sugarcane. Unlike most plant pathogenic bacteria, X. albilineans does not possess a Hrp-Type Three Secretion System. Pathogenicity of this bacterial species must therefore rely on other virulence factors. X. albilineans produces albicidin, a toxin and potent inhibitor of DNA gyrase which inhibits proplastic DNA replication. Consequently, chloroplast differentiation is blocked and disease symptoms develop. Albicidin is also bactericidal at nanomolar concentrations against a range of Gram-positive and Gram-negative bacteria. This potent and novel antibiotic is especially of interest because of its activity against Escherichia coli, a species causing nosocomial diseases. Sequencing and annotation of the entire genome of X. albilineans recently revealed that X. albilineans possesses 12 large genes encoding nonribosomal peptide synthetases (NRPSs) which are located in four gene clusters covering 4% of the genome (1). One of these NRPS clusters corresponds to the previously identified albicidin biosynthesis gene cluster. The mode of action of this antibiotic was extensively studied but its structure remains unknown. Characterization of albicidin is the main bottleneck which slows development of its therapeutic application. X. albilineans is a slow growing bacterium and production yields of albicidin are low, i.e. it turned out to be extremely tedious to obtain sufficient amounts for structure elucidation. To overcome this problem, we successfully considered heterologous overproduction by transferring all albicidin biosynthesis genes into the fast growing bacterium Xanthomonas axonopodis pv. vesicatoria (2). Production of albicidin in this heterologous system already allowed us to obtain several milligrams of pure compound and promising preliminary results regarding the structural characterization of albicidin. As an example, 1H-NMR analyses showed the presence of a number of para-