The rhlA/rhlB/rhlC orthologs of these two Burkholderia species are highly similar to one another with nucleotide identity ranging from 89% to 96%. Furthermore, the

protein encoded by these genes share almost 50% identity with those of P. aeruginosa PAO1, which possesses a single copy of these genes on its genome. Another interesting observation is that for P. aeruginosa, rhlA and rhlB are found in one operon whereas rhlC is found in a different Akt inhibitor bicistronic operon (Figure 1). Finally, Table 1 shows that the remaining ORFs present in the rhl gene clusters, including the one adjacent to rhlC in P. aeruginosa, all seem to have functions related to MEK inhibitor transport or efflux. Table 1 Predicted functions of the remaining ORFs Gene annotation Predicted function1 PA1131 Probable Major Facilitator Superfamily (MFS) Transporter BTH_II1077/BTH_II1879 Drug Resistance Transporter, EmrB/QacA Family BTH_II1078/BTH_II1878 Hypothetical Protein BTH_II1080/BTH_II1876 RND Efflux System, Outer Membrane Lipoprotein, NodT Family BTH_II1081/BTH_II1875 Multidrug Resistance Protein (EmrA) BURPS1710b_0372/BURPS1710b_2096 Multidrug Resistance Protein (BcrA) BURPS1710b_0370/BURPS1710b_2098 RND Efflux System, Outer Membrane Lipoprotein, NodT Family BURPS1710b_0368/BURPS1710b_2100 Multidrug Selleck CP673451 Resistance Protein (EmrA) 1 Predicted functions from http://​www.​pseudomonas.​com and

http://​www.​burkholderia.​com. Predicted functions of the remaining ORFs present in the

rhl gene cluster in B. thailandensis and B. pseudomallei, including the one adjacent to rhlC in P. aeruginosa. Figure 1 Genetic arrangement of rhlA, rhlB and rhlC in the genomes. Schematic representation of the bicistronic P. aeruginosa PAO1 http://​www.​pseudomonas.​com regions containing the rhlAB and rhlC genes as well as the two identical gene clusters containing the homologous rhlA, rhlB and rhlC genes in B. thailandensis E264 and B. pseudomallei 1710b http://​www.​burkholderia.​com. Bumetanide Rhamnolipid production by B. thailandensis and B. pseudomallei Due to the high similarity between the rhlA/rhlB/rhlC genes found in P. aeruginosa and their homologs in B. thailandensis, the latter was tested for the production of rhamnolipids. Using B. thailandensis in various rhamnolipid production growth conditions, the initial results from liquid chromatography/mass spectrometry (LC/MS) analysis revealed a dominant peak in the total-ion chromatograph (TIC). This peak presented a pseudomolecular ion of m/z 761 in negative-ion mode, a value that is compatible with a compound consisting of two L-rhamnose molecules as well as two β-hydroxytetradecanoic acids. A corresponding rhamnolipid, 2-O-α-L-rhamnopyranosyl-α-L-rhamnopyranosyl-β-hydroxytetradecanoyl-β-hydroxytetradecanoate (Rha-Rha-C14-C14), with a molecular weight of 762 Da, has been previously reported from B. pseudomallei and B. plantarii cultures [22, 23, 27].