Table 1

Production of tyramine and putrescine by L. brevis IOEB 9809 in the presence of diverse BA precursors
BA precursor Agmatine Tyrosine Agmatine +Tyrosine
BA produced Put (μM) Tym (μM) Put (μM) Tym (μM)
Saliva 22.33 ± 2.52a 26.08 ± 0.13a 32.66 ± 2.76ab 56.46 ± 3.06ad
G pH 5.0 37.67 ± 3.06b 78.29 ± 1.07b 57.27 ± 11.69c 194.63 ± 9.69e
G pH 4.1 36.00 ± 3.00b 122.30 ± 2.55c 39.22 ± 5.01b 174.46 ± 8.07f
G pH 3.0 11.59 ± 0.56d 82.18 ± 1.10bc 15.33 ± 1.05da 113.87 ± 5.27c
G pH 2.1 10.54 ± 0.46d 74.21 ± 1.07bd 14.32 ± 1.08da 76.10 ± 3.53b
G pH 1.8 11.21 ± 0.45d 62.26 ± 1.09d 13.42 ± 1.01da 50.91 ± 2.36ad

Tyramine (Tym) and putrescine (Put) production were detected by RP-HPLC during the saliva and gastric stress simulation in presence of 10 mM tyrosine, 4.38 mM agmatine or both. Results are expressed in μM of BA produced by 108 CFU mL-1 in 20 min, they are the mean of three independent experiments and there are corrected for the CFU added to the experiment. Putrescine and tyramine were below the detection limits (2 nM and 2.5 nM) in the uninoculated MRS and in absence of the corresponding BA precursor. Differences were assessed by Anova test. Different superscript letters associated with values of the same BA indicate statistically significant differences (P < 0.05).

Russo et al.

Russo et al. BMC Microbiology 2012 12:247   doi:10.1186/1471-2180-12-247

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