dc.creator | Mortera, Pablo | |
dc.creator | Pudlik, Agata | |
dc.creator | Magni, Christian | |
dc.creator | Alarcon, Sergio Hugo | |
dc.creator | Lolkema, Juke S. | |
dc.date.accessioned | 2016-06-07T15:27:22Z | |
dc.date.available | 2016-06-07T15:27:22Z | |
dc.date.created | 2016-06-07T15:27:22Z | |
dc.date.issued | 2013-08 | |
dc.identifier | Mortera, Pablo; Pudlik, Agata; Magni, Christian; Alarcon, Sergio Hugo; Lolkema, Juke S.; Ca2+-citrate uptake and metabolism in Lactobacillus casei ATCC334; American Society for Microbiology; Applied And Environmental Microbiology; 79; 15; 8-2013; 4603-4612 | |
dc.identifier | 0099-2240 | |
dc.identifier | http://hdl.handle.net/11336/6089 | |
dc.description.abstract | The putative citrate metabolic pathway in Lactobacillus casei ATCC 334 consists of the transporter CitH, a proton symporter of the citrate-divalent metal ion family of transporters CitMHS, citrate lyase, and the membrane-bound oxaloacetate decarboxylase complex OAD-ABDH. Resting cells of Lactobacillus casei ATCC 334 metabolized citrate in complex with Ca2+ and not as free citrate or the Mg2+-citrate complex, thereby identifying Ca2+-citrate as the substrate of the transporter CitH. The pathway was induced in the presence of Ca2+ and citrate during growth and repressed by the presence of glucose and of galactose, most likely by a carbon catabolite repression mechanism. The end products of Ca2+-citrate metabolism by resting cells of Lb. casei were pyruvate, acetate, and acetoin, demonstrating the activity of the membrane-bound oxaloacetate decarboxylase complex OAD-ABDH. Following pyruvate, the pathway splits into two branches. One branch is the classical citrate fermentation pathway producing acetoin by α-acetolactate synthase and α-acetolactate decarboxylase. The other branch yields acetate, for which the route is still obscure. Ca2+-citrate metabolism in a modified MRS medium lacking a carbohydrate did not significantly affect the growth characteristics, and generation of metabolic energy in the form of proton motive force (PMF) was not observed in resting cells. In contrast, carbohydrate/Ca2+-citrate cometabolism resulted in a higher biomass yield in batch culture. However, also with these cells, no generation of PMF was associated with Ca2+-citrate metabolism. It is concluded that citrate metabolism in Lb. casei is beneficial when it counteracts acidification by carbohydrate metabolism in later growth stages. | |
dc.language | eng | |
dc.publisher | American Society for Microbiology | |
dc.relation | info:eu-repo/semantics/altIdentifier/ark/http://aem.asm.org/content/79/15/4603.long | |
dc.relation | info:eu-repo/semantics/altIdentifier/doi/http://dx.doi.org/10.1128/AEM.00925-13 | |
dc.rights | https://creativecommons.org/licenses/by-nc-sa/2.5/ar/ | |
dc.rights | info:eu-repo/semantics/openAccess | |
dc.subject | Lactobacillus Casei | |
dc.subject | Citrate Fermentation | |
dc.subject | Metabolic Energy | |
dc.title | Ca2+-citrate uptake and metabolism in Lactobacillus casei ATCC334 | |
dc.type | info:eu-repo/semantics/article | |
dc.type | info:ar-repo/semantics/artículo | |
dc.type | info:eu-repo/semantics/publishedVersion | |