, 2010) and VctA and IrgA in Vibrio cholerae (Mey
et al., 2002). However, little is known about multiple receptors for a cognate siderophore with the exception of the type I ferric pyoverdine receptors FpvA and FpvB in Pseudomonas aeruginosa (Ghysels et al., 2004). Because fpvA and fpvB are located on separate replicons and both proteins exhibit 54% amino acid sequence similarity, our study presents the first examples of two IROMPs encoded by different tandem genes in the same operon functioning as the receptors for the same Tacrolimus datasheet cognate siderophore. This strategy may provide an alternative backup system – that is, protection against mutational loss – for VF-mediated iron acquisition in V. parahaemolyticus. However, the coexistence of pvuA1 and pvuA2 in the VF-utilization cluster raise the possibility that either pvuA1 or pvuA2 actually preferentially binds and transports an unknown siderophore ligand that is structurally related to VF. We also determined the specificities of the ferric VF receptors on three sets of TonB systems for ferric VF. It is noteworthy high throughput screening assay that TonB2 is exclusively required for the PvuA1-mediated transport of ferric VF; meanwhile, the PvuA2-mediated transport of ferric VF is supported by both TonB1 and TonB2. Further studies are needed to understand the specificities of TonB for other V. parahaemolyticus receptors for the uptake of heme/hemoglobin as well as exogenous siderophores such
as aerobactin (Funahashi et al., 2003) and ferrichrome (Funahashi
Aldol condensation et al., 2009). We thank T. Kuroda for providing E. coli β2155 and a suicide vector pXAC623 and for his helpful comments. This work was supported in part by a grant from the Cooperative and Collaboration Agreement between Ehime University and Matsuyama University. “
“Members of the genus Rhodococcus were investigated for their ability to produce glycogen during cultivation on gluconate or glucose. Strains belonging to Rhodococcus ruber, Rhodococcus opacus, Rhodococcus fascians, Rhodococcus erythropolis and Rhodococcus equi were able to produce glycogen up to 0.2–5.6% of cellular dry weight (CDW). The glycogen content varied from 0.8% to 3.2% of CDW in cells of R. opacus PD630, which is a well-known oleaginous bacterium, during the exponential growth phase, when cultivated on diverse carbon sources. Maltose and pyruvate promoted glycogen accumulation by cells of strain PD630 to a greater extent than glucose, gluconate, lactose, sucrose or acetate. This strain was able to produce triacylglycerols, polyhydroxyalkanoates and glycogen as storage compounds during growth on gluconate, although triacylglycerols were always the main product under the conditions of this study. Cerulenin, an inhibitor of de novo fatty acid synthesis, inhibited the accumulation of triacylglycerols from gluconate and increased the content of polyhydroxyalkanoates (from 2.0% to 4.2%, CDW) and glycogen (from 0.1% to 3.0%, CDW).