Rabbit anti-Human HPR polyclonal antibody

The HprK serine kinase is a component of the phosphoenolpyruvate phosphotransferase system (PTS) of bacteria that generally regulates catabolite repression through phosphorylation/dephosphorylation of the PTS protein PtsH at a conserved serine residue. However, many bacteria do not encode a complete PTS or even have an HprK homologue. Xanthomonas campestris pv. campestris (Xcc) is a pathogen that cause black rot disease in crucifer plants and one of the few Gram-negative bacteria that encodes a homologue of HprK protein (herein HprK(Xcc)). To gain insight into the role of HprK(Xcc) and other PTS-related components in Xcc we individually mutated and phenotypically assessed the resulting strains. Deletion of hprK(Xcc) demonstrated its requirement for virulence and other diverse cellular processes associated including extracellular enzyme activity, extracellular-polysaccharide production and cell motility. Global transcriptome analyses revealed the HprK(Xcc) had a broad regulatory role in Xcc. Additionally, through overexpression, double gene deletion and transcriptome analysis we demonstrated that hprK(Xcc) shares an epistatic relationship with ptsH. Furthermore, we demonstrate that HprK(Xcc) is a functional serine kinase, which has the ability to phosphorylate PtsH. Taken together, the data illustrates the previously unappreciated global regulatory role of HprK(Xcc) and previously uncharacterized PTS components that control virulence in this pathogen.

This study focused on continuous-flow hydrogen production by Thermotoga neapolitana at a hydraulic retention time (HRT) decreasing from 24 to 5 h. At each HRT reduction, the hydrogen yield (HY) immediately dropped, but recovered during prolonged cultivation at constant HRT. The final HY in each operating period decreased from 3.4 ( +/- 0.1) to 2.0 ( +/- 0.0) mol H-2/mol glucose when reducing the HRT from 24 to 7h. Simultaneously, the hydrogen production rate (HPR) and the liquid phase hydrogen concentration (H-2aq) increased from 82 ( +/- 1) to 192 ( +/- 4) mL/L/h and from 9.1 ( +/- 0.3) to 15.6 ( +/- 0.7) mL/L, respectively. Additionally, the effluent glucose concentration increased from 2.1 ( +/- 0.1) to above 10 mM. Recirculating H-2-rich biogas prevented the supersaturation of H-2aq reaching a value of 9.3 ( +/- 0.7) mL/L, resulting in complete glucose consumption and the highest HPR of 277 mL/L/h at an HRT of 5 h.