The click here spray voltage was 3 kV, the tube lens offset −132 V and the skimmer offset 5 V. The ion transfer capillary temperature and vaporizer temperature were 250 and 300°C respectively. All the amines

give a m/z signals that correspond to the structure [M-H]-. Each amine was injected at 1 to 10 μg.mL-1 for mass characterization. Collision-induced dissociation (CID) was performed from 20 to 30 eV under 1.5 mTor of argon. PCR amplification L. plantarum identification was performed by 16S ribosomal RNA gene sequencing and multiplex PCR using recA gene-derived primers [43]. Chromosomal DNA from L. plantarum was extracted using the Wizard Genomic Kit (Promega, Charbonnières les Bains, France). Amplification and sequencing of the 16S gene was performed using the High Fidelity Taq polymerase (Roche, Meylan, France) and the universal primers BSF8 and

BSR1541 [54]. Amplification conditions were 94°C for 2 min, 10 cycles of 94°C for 15 s, 52°C for 30 s, and 72°C for 1 min 30 s, followed by 20 cycles with an additional time of 5 s for each elongation reaction and a final extension at 72°C for 10 min. Multiplex PCR protocol developed by Torriani et al. [43] was performed with Go Taq polymerase (Promega, Charbonnières JNK-IN-8 nmr les Bains, France) and was modified for dNTP concentration (0.2 mM inside of 12 μM) and for annealing time (20 s inside of 10 s). The L. plantarum IR BL0076 tyrDC and tyrP genes were amplified by PCR using High Fidelity Taq polymerase (Roche, Meylan, France) and primers tyrSa

and nhaCa based on the tyrS and nhaC sequences which flanked tyrDC and tyrP genes of L. brevis NS77 [GenBank : EU195891]. Amplification was performed in a final volume of 50 μL, with 5 μL of Expand High Fidelity buffer (Roche, Meylan, France), 1 μL of 10 mM dNTP mix (Fermentas, Villebon sur Yvette, SPTLC1 France), 1 μL of each primer at 20 μM, 2.6 U of Expand High Fidelity enzyme mix (Roche, Meylan, France), and 1 μL of extract DNA. The amplification program was applied in a Bio-Rad thermocycler following the manufacturer’s instructions for long fragments. PCR fragments were purified using the GenElute PCR purification kit (Sigma, Saint Quentin Fallavier, France) and sent to Benckman Coulter Genomics (United kingdom) for sequencing. Total RNA extraction and RT-PCR L. plantarum RNA was extracted after various periods of growth in media 1 and 2 (when the cultures reached at OD600nm = 1.1, 1.6 and 1.8). Aliquots of 25 mL of culture were harvested, and the cells pelleted and washed with 10 mL of Tris HCl 10 mM pH 8. The cells were then broken in 1 mL of Tri-Reagent (Sigma, Saint Quentin Fallavier, France) in a screw cap tube containing 200 mg of beads (100 μm) in a BIX 1294 Precellys 24 ultrasound device (Ozyme, Saint Quentin en Yvelines, France) programmed as follows: 6500, 3 × 30 s, twice. Cell fragments were pelleted by centrifugation (12,000 × g, 10 min, 4°C) and the supernatant was transferred to an Eppendorf tube and 200 μL of chloroform was added.