Long-lasting cough in an adult German population: incidence, symptoms, and related pathogens.

Studies of the incidence of pertussis in adults have shown that it accounts for only 5-15% cases of prolonged coughing. We assessed the burden of suffering related to prolonged coughing and tried to identify further causative agents. Based on a sentinel study with 35 general practitioners in two German cities (Krefeld, Rostock), with 3,946 patients fulfilling the inclusion criteria, we estimated the incidence of prolonged coughing in adults.

Lrp of Corynebacterium glutamicum controls expression of the brnFE operon encoding the export system for L-methionine and branched-chain amino acids.

Corynebacterium glutamicum possesses export systems for various amino acids including BrnFE, a two-component export system for L-methionine and the branched-chain amino acids L-valine, L-isoleucine and L-leucine. A gene for a putative transcriptional regulator of the Lrp family is transcribed divergently to the brnFE operon and is required for L-isoleucine export. By comparing global gene expression changes due to L-isoleucine addition we revealed increased brnFE expression in response to L-isoleucine in C.

Metabolic engineering of Corynebacterium glutamicum for L-serine production.

Although L-serine proceeds in just three steps from the glycolytic intermediate 3-phosphoglycerate, and as much as 8% of the carbon assimilated from glucose is directed via L-serine formation, previous attempts to obtain a strain producing L-serine from glucose have not been successful. We functionally identified the genes serC and serB from Corynebacterium glutamicum, coding for phosphoserine aminotransferase and phosphoserine phosphatase, respectively. The overexpression of these genes, together with the third biosynthetic serA gene, serA(delta197), encoding an L-serine-insensitive 3-phosphoglycerate dehydrogenase, yielded only traces of L-serine, as did the overexpression of these genes in a strain with the L-serine dehydratase gene sdaA deleted.

Functional analysis of all aminotransferase proteins inferred from the genome sequence of Corynebacterium glutamicum.

Twenty putative aminotransferase (AT) proteins of Corynebacterium glutamicum, or rather pyridoxal-5'-phosphate (PLP)-dependent enzymes, were isolated and assayed among others with L-glutamate, L-aspartate, and L-alanine as amino donors and a number of 2-oxo-acids as amino acceptors. One outstanding AT identified is AlaT, which has a broad amino donor specificity utilizing (in the order of preference) L-glutamate > 2-aminobutyrate > L-aspartate with pyruvate as acceptor. Another AT is AvtA, which utilizes L-alanine to aminate 2-oxo-isovalerate, the L-valine precursor, and 2-oxo-butyrate.

Export of L-isoleucine from Corynebacterium glutamicum: a two-gene-encoded member of a new translocator family.

Bacteria possess amino acid export systems, and Corynebacterium glutamicum excretes L-isoleucine in a process dependent on the proton motive force. In order to identify the system responsible for L-isoleucine export, we have used transposon mutagenesis to isolate mutants of C. glutamicum sensitive to the peptide isoleucyl-isoleucine.