Regulation of ldh expression during biotin-limited growth of Corynebacterium glutamicum. - Archive ouverte HAL Accéder directement au contenu
Article Dans Une Revue Microbiology Année : 2009

Regulation of ldh expression during biotin-limited growth of Corynebacterium glutamicum.

Résumé

Corynebacterium glutamicum is a biotin-auxotrophic bacterium and some strains efficiently produce glutamic acid under biotin-limiting conditions. In an effort to understand C. glutamicum metabolism under biotin limitation, growth of the type strain ATCC 13032 was investigated in batch cultures and a time-course analysis was performed. A transient excretion of organic acids was observed and we focused our attention on lactate synthesis. Lactate synthesis was due to the ldh-encoded l-lactate dehydrogenase (Ldh). Features of Ldh activity and ldh transcription were analysed. The ldh gene was shown to be regulated at the transcriptional level by SugR, a pleiotropic transcriptional repressor also acting on most phosphotransferase system (PTS) genes. Electrophoretic mobility shift assays (EMSAs) and site-directed mutagenesis allowed the identification of the SugR-binding site. Effector studies using EMSAs and analysis of ldh expression in a ptsF mutant revealed fructose 1-phosphate as a highly efficient negative effector of SugR. Fructose 1,6-bisphosphate also affected SugR binding.

Dates et versions

hal-00374713 , version 1 (09-04-2009)

Identifiants

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Christiane Dietrich, Aimé Nato, Bruno Bost, Pierre Le Maréchal, Armel Guyonvarch. Regulation of ldh expression during biotin-limited growth of Corynebacterium glutamicum.. Microbiology, 2009, 155 (4), pp.1360-75. ⟨10.1099/mic.0.022004-0⟩. ⟨hal-00374713⟩
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