A new family of putative signaling molecules having a 2(5H)-furanone configuration has been described in Lactobacillus helveticus, L. plantarum, L. paraplantarum, L. sanfranciscensis, Enterococcus faecalis and Salmonella enterica. The release of these molecules was cell density dependant and was enhanced by oxidative, acid and heat stresses. The cell exposure to conditioned media containing 2(5H)-furanones triggered morphological changes and autolysin production in L. helveticus and E. faecalis. Experimental evidences of the involvement of these furanones in the intra- and inter-specific communication have been obtained. The principal aim of this work was the identification of the precursors of these molecules and their biosynthetic mechanism on the basis of the hypothesis that the endogenous conversion of cell unsaturated fatty acids and the enzymatic routes giving rise to the family of the oxylipins are involved in their biosynthesis. Lactobacillus helveticus, L. sanfranciscensis, Enterococcus faecalis and Salmonella enterica were grown in presence of labeled unsaturated fatty acids in order to trace their integration in the membrane phospholipids and their metabolic fate by using GC-Mass spectrometer and the single ion monitoring technique also associated with solid phase microextraction. Compounds derived from the oxidative metabolism of polyunsaturated fatty acids were detected with GC-Mass spectrometry. Intra- and inter-specific activity was evaluated by detecting the production of autolysins with renaturating SDS–Page electrophoresis as well as by quantifying violacein produced by Chromobacterium violaceum 30191 which was used as indicator organism for quorum sensing bioassay. The analysis of the distribution of the labelled carbon of the supplemented unsaturated fatty acids into the various cell components and in the released metabolites allowed the formulation of a biosynthesis hypothesis.
Ndagijimana M., Vannini L., Sado S., Montanari C., Vernocchi P., Guerzoni M. E. (2008). 2(5H)-furanones as signaling molecole in some Gram + and Gram – species: biosynthesis and intra and interspecific activity. ABERDEEN : University of Aberdeen Central Printing Service.
2(5H)-furanones as signaling molecole in some Gram + and Gram – species: biosynthesis and intra and interspecific activity
NDAGIJIMANA, MAURICE;VANNINI, LUCIA;SADO KAMDEM, SYLVAIN LEROY;MONTANARI, CHIARA;VERNOCCHI, PAMELA;GUERZONI, MARIA ELISABETTA
2008
Abstract
A new family of putative signaling molecules having a 2(5H)-furanone configuration has been described in Lactobacillus helveticus, L. plantarum, L. paraplantarum, L. sanfranciscensis, Enterococcus faecalis and Salmonella enterica. The release of these molecules was cell density dependant and was enhanced by oxidative, acid and heat stresses. The cell exposure to conditioned media containing 2(5H)-furanones triggered morphological changes and autolysin production in L. helveticus and E. faecalis. Experimental evidences of the involvement of these furanones in the intra- and inter-specific communication have been obtained. The principal aim of this work was the identification of the precursors of these molecules and their biosynthetic mechanism on the basis of the hypothesis that the endogenous conversion of cell unsaturated fatty acids and the enzymatic routes giving rise to the family of the oxylipins are involved in their biosynthesis. Lactobacillus helveticus, L. sanfranciscensis, Enterococcus faecalis and Salmonella enterica were grown in presence of labeled unsaturated fatty acids in order to trace their integration in the membrane phospholipids and their metabolic fate by using GC-Mass spectrometer and the single ion monitoring technique also associated with solid phase microextraction. Compounds derived from the oxidative metabolism of polyunsaturated fatty acids were detected with GC-Mass spectrometry. Intra- and inter-specific activity was evaluated by detecting the production of autolysins with renaturating SDS–Page electrophoresis as well as by quantifying violacein produced by Chromobacterium violaceum 30191 which was used as indicator organism for quorum sensing bioassay. The analysis of the distribution of the labelled carbon of the supplemented unsaturated fatty acids into the various cell components and in the released metabolites allowed the formulation of a biosynthesis hypothesis.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
