title: Differential Gene Expression by Lactobacillus plantarum WCFS1 in Response to Phenolic Compounds Reveals New Genes Involved in Tannin Degradation.
abstract: Lactobacillus plantarumis a lactic acid bacterium that can degrade food tannins by the successive action of tannase and gallate decarboxylase enzymes. In theL. plantarumgenome, the gene encoding the catalytic subunit of gallate decarboxylase (lpdC, orlp_2945) is only 6.5 kb distant from the gene encoding inducible tannase (L. plantarumtanB[tanBLp], orlp_2956). This genomic context suggests concomitant activity and regulation of both enzymatic activities. Reverse transcription analysis revealed that subunits B (lpdB, orlp_0271) and D (lpdD, orlp_0272) of the gallate decarboxylase are cotranscribed, whereas subunit C (lpdC, orlp_2945) is cotranscribed with a gene encoding a transport protein (gacP, orlp_2943). In contrast, the tannase gene is transcribed as a monocistronic mRNA. Investigation of knockout mutations of genes located in this chromosomal region indicated that only mutants of the gallate decarboxylase (subunits B and C), tannase, GacP transport protein, and TanR transcriptional regulator (lp_2942) genes exhibited altered tannin metabolism. The expression profile of genes involved in tannin metabolism was also analyzed in these mutants in the presence of methyl gallate and gallic acid. It is noteworthy that inactivation oftanRsuppresses the induction of all genes overexpressed in the presence of methyl gallate and gallic acid. This transcriptional regulator was also induced in the presence of other phenolic compounds, such as kaempferol and myricetin. This study complements the catalog ofL. plantarumexpression profiles responsive to phenolic compounds, which enable this bacterium to adapt to a plant food environment.IMPORTANCELactobacillus plantarumis a bacterial species frequently found in the fermentation of vegetables when tannins are present.L. plantarumstrains degrade tannins to the less-toxic pyrogallol by the successive action of tannase and gallate decarboxylase enzymes. The genes encoding these enzymes are located close to each other in the chromosome, suggesting concomitant regulation. Proteins involved in tannin metabolism and regulation, such GacP (gallic acid permease) and TanR (tannin transcriptional regulator), were identified by differential gene expression in knockout mutants with mutations in genes from this region. This study provides insights into the highly coordinated mechanisms that enableL. plantarumto adapt to plant food fermentations.
authors.affiliation: Laboratorio de Biotecnología Bacteriana, Instituto de Ciencia y Tecnología de Alimentos y Nutrición, ICTAN-CSIC, Madrid, Spain.
authors.forename: Inés
authors.initials: I
authors.lastname: Reverón
authors.affiliation: Laboratorio de Biotecnología Bacteriana, Instituto de Ciencia y Tecnología de Alimentos y Nutrición, ICTAN-CSIC, Madrid, Spain.
authors.forename: Natalia
authors.initials: N
authors.lastname: Jiménez
authors.affiliation: Laboratorio de Biotecnología Bacteriana, Instituto de Ciencia y Tecnología de Alimentos y Nutrición, ICTAN-CSIC, Madrid, Spain.
authors.forename: José Antonio
authors.initials: JA
authors.lastname: Curiel
authors.affiliation: Laboratorio de Biotecnología Bacteriana, Instituto de Ciencia y Tecnología de Alimentos y Nutrición, ICTAN-CSIC, Madrid, Spain.
authors.forename: Elena
authors.initials: E
authors.lastname: Peñas
authors.affiliation: Laboratorio de Biotecnología Bacteriana, Instituto de Ciencia y Tecnología de Alimentos y Nutrición, ICTAN-CSIC, Madrid, Spain.
authors.forename: Félix
authors.initials: F
authors.lastname: López de Felipe
authors.affiliation: Laboratorio de Biotecnología Bacteriana, Instituto de Ciencia y Tecnología de Alimentos y Nutrición, ICTAN-CSIC, Madrid, Spain.
authors.forename: Blanca
authors.initials: B
authors.lastname: de Las Rivas
authors.affiliation: Laboratorio de Biotecnología Bacteriana, Instituto de Ciencia y Tecnología de Alimentos y Nutrición, ICTAN-CSIC, Madrid, Spain rmunoz@ictan.csic.es.
authors.forename: Rosario
authors.initials: R
authors.lastname: Muñoz
mesh_terms: D002262:Carboxy-Lyases / Q000235:genetics / Q000378:metabolism; D002265:Carboxylic Ester Hydrolases / Q000235:genetics / Q000378:metabolism; D005285:Fermentation; D005707:Gallic Acid / Q000031:analogs & derivatives* / Q000494:pharmacology*; D020869:Gene Expression Profiling; D055786:Gene Knockout Techniques; D048191:Lactiplantibacillus plantarum / Q000187:drug effects* / Q000201:enzymology / Q000235:genetics* / Q000378:metabolism; D009154:Mutation; D013634:Tannins / Q000378:metabolism*
chemical_list: D013634:Tannins; C052082:methyl gallate; D005707:Gallic Acid; D002265:Carboxylic Ester Hydrolases; C022711:tannase; D002262:Carboxy-Lyases
keywords: fermentation; food phenolics; lactic acid bacteria; tannins