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Regulation of expression of the Lactococcus lactis subsp. lactis biovar diacetylactis citrate transport system

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Publication Date
Keywords
  • [Sdv:Aen] Life Sciences/Food And Nutrition
  • [Sdv:Aen] Sciences Du Vivant/Alimentation Et Nutrition
  • [Sdv:Ida] Life Sciences/Food Engineering
  • [Sdv:Ida] Sciences Du Vivant/Ingénierie Des Aliments
Disciplines
  • Biology

Abstract

Lait (1998) 78, 11-16 © InralElsevier, Paris Il Regulation of expression of the Lactococcus lactis subsp. lactis biovar diacetylactis citrate transport system Paloma L6pez a*, Djamel Drider ", Nièves Garcfa-Quintans a, Maria Angeles Corrales a, Christian Magni b, Mauricio Martin b, Diego de Mendoza b a Centro de Investigaciones Biolôgicas (C.S./.c.), Velâzquez 144,28006 Madrid, Spain b Programa Multidisciplinario de Biologia Experimental (Promubie, Conicet) and Departamento de Microbiologia, Facultad de Ciencias Bioquimicas y Farmaceûticas, Universidad Nacional de Rosario, Suipacha 531,2000 Rosario, Argentina Abstract - Citrate metabolism performed by a number of lactic acid bacteria yields volatile com- pounds, such as diacetyl and acetaldehyde, which are important for flavour development in fer- mented milk products. Citrate uptake in Lactococcus laetis subsp. laetis biovar diacetylactis and Leuconostoc mesenteroides subsp. mesenteroides is catalyzed by a secondary carrier, the citrate permease P (CitP). The presence of CitP is essential for citrate utilization, since in its absence no citrate metabolism is observed although ail enzymes involved in conversion of citrate are present inside the cells. In this review the genetic organization of the plasmid encoding the citrate transport system of lactococci is described, the posttranscriptional regulation of the citQRP operon is presented and the influence of external pH on citP transcription, citrate uptake and cometabolism of citrate and glucose is discussed. These last studies reveal a novel molecular mechanism that improves the adaptation of L. diacetylactis to acidic pH. © Inra/Elsevier, Paris. Lactococcus lactis subsp. lactis biovar diacetylactis / citrate transport 1 regulation of gene expression 1 lactic acid bacteria 1 acidic stress Résumé - Régulation de 1'expression du système de transport du citrate chez Lactococcus lactis subsp.lactis biovar diacetylactis. Le métabolisme du citrate chez certaines bactéries lac- tique

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