(a) Enterococcus faecium was inserted into the liquid medium to cultivate and detect tyramine content. “LM1, LM3, LM6, LM9 and LM24” in figure indicate Enterococcus faecium was inserted into the liquid medium to cultivate for 1, 3, 6, 9 and 24 h. (b) Enterococcus faecium was inserted into the sterile supernatant of LM1, LM3, LM6, LM9, and LM24 to cultivate detect tyramine content. “S1, S3, S6, S9 and S24” in figure indicate Enterococcus faecium was inserted into the sterile supernatant of LM1, LM3, LM6, LM9, and LM24 to cultivate for 1 h. (c) Expression of tyrDC genes in LM1 and S1, LM3 and S3, LM9 and S9. (d) Expression of tyrP genes in LM1 and S1, LM3 and S3, LM9 and S9. “*” in the figures indicate different groups with significant differences (p < .05). “**” in the figures indicate different groups with great significant differences (p < .01)