Soleucine, and L-valine (Eggeling and Sahm, 2003). Hashimoto et al. lately showed that L-glutamate, L-aspartate and BNP Protein MedChemExpress L-phenylalanine are secreted by means of a mechano-sensitive channel by passive diffusion in C. glutamicum (Hashimoto et al., 2012). Inside the past, the export of amino acids by bacteria was believed to be an artificial result of industrial overproduction and to have no biological relevance. But, next to regulation with the biosynthesis of an amino acid and degradation, the corresponding export may be an essential possibility to preserve amino acid homoeostasis, specially in peptide-rich environments (Eggeling and Sahm, 2003). Genes for histidine utilization, that are present in several pathogenic Corynebacterium species, are missing in C. glutamicum (Schr er et al., 2012). Nonetheless, Bellmann and colleagues (2001) demonstrated the potential of C. glutamicum to export histidine, which may well enable to retain histidine homoeostasis in an environment wealthy in histidine-containing peptides. Addition of two mM His-Ala dipeptide to a C. glutamicum culture resulted within a steady raise of external histidine concentration (Bellmann et al., 2001). The export, nonetheless, seems to become rather inefficient as internal histidine concentration rises from zero to 200 mM just after addition in the dipeptide (Bellmann et al., 2001). Considering the fact that C. glutamicum will not secrete any peptidases (Erdmann et al., 1993), the only explanation for the rising external histidine?2013 The Authors. Microbial Biotechnology published by John Wiley Sons Ltd and Society for Applied Microbiology, Microbial Biotechnology, 7, five?Histidine in C. glutamicum concentration is export of histidine that was cleaved of in the dipeptide itracellularly. On the other hand, no candidate gene encoding the exporter has been proposed so far. Interestingly, histidine acts as a TRAIL/TNFSF10 Protein custom synthesis co-inducers of lysE transcription, a gene encoding the L-lysine and L-arginine efflux program in C. glutamicum, despite the fact that histidine is just not exported by LysE (Bellmann et al., 2001). There is no explanation, why histidine acts as co-inducer in the exporter, that is unable to export L-histidine. In fact, this may trigger a disadvantageous circumstance for the cell as higher histidine concentrations could trigger efflux of L-lysine and L-arginine though their concentrations are low. This negative effect, nevertheless, could possibly somehow be counteracted by the higher Km worth of 20 mM for L-lysine export (Br r and Kr er, 1991).Acknowledgements R. K. Kulis-Horn is supported by a CLIB-GC (Graduate Cluster Industrial Biotechnology) Phd grant co-funded by the Ministry of Innovation, Science and Research on the federal state of North Rhine-Westphalia (MIWF). This perform was a part of the SysEnCor investigation project (Grant 0315598E) funded by the German Federal Ministry of Education and Analysis (BMBF). We thank Katharina Pfeifer-Sancar and Dr. Christian R kert for delivering unpublished RNA-Seq data for C. glutamicum. Extra thanks goes to Elisabeth Zelle (Investigation Centre J ich) for assistance with metabolic modelling of C. glutamicum.Conflict of interest None declared.
Chiu et al. BMC Microbiology 2013, 13:190 biomedcentral/1471-2180/13/RESEARCH ARTICLEOpen AccessLactobacillus plantarum MYL26 induces endotoxin tolerance phenotype in Caco-2 cellsYi-Heng Chiu1, Ying-Chen Lu2, Chu-Chyn Ou1,3,four, Shiao-Lin Lin5, Chin-Chi Tsai1, Chien-Tsai Huang1 and Meei-Yn Lin1AbstractBackground: Crohn’s disease and ulcerative colitis will be the significant varieties of chronic inflammatory bowel disease occ.