Abstract:In this study, Klebsiella spp., Enterobacter cloacae, and Pantoea agglomerans, which are dominant biogenic amine-producing bacteria in smoked and fermented horsemeat sausages, were used as test strains; quorum-sensing compounds were detected by a parallel line assay of Agrobacterium tumefaciens A136, and experimental evidence showed that quorum sensing was observed in all three of the dominant strains. N-acylhomoserine lactone (AHL) activity assay, detection, and quantification of biogenic amines, as well as correlation analysis between β-galactosidase activity and biogenic amines were conducted. The results indicated that both Klebsiella spp. and the β-galactosidase activity in P. agglomerans showed a significant positive correlation (RPearson > 0.817, P < 0.01) with putrescine, cadaverine, histamine, and tyramine. The β-galactosidase activity in E. cloacae was significantly correlated with cadaverine (RPearson is 0.923, P = 0.00 < 0.01). In addition, the secretion of AHLs affected the accumulation of biogenic amines, showing a synergistic effect. Meanwhile, biofilm formation and cell hydrophobicity experiments were carried out at 28 ℃ and 37 ℃, respectively. The results indicated that the absorption capacities of xylene, chloroform, and ethyl acetate, as well as cell hydrophobicity values were different for the three dominant strains. Furthermore, the ability of Klebsiella spp. to form biofilms did not show significant difference (P = 0.095 > 0.05), while significant differences (P = 0.0315 < 0.05, P = 0.047 < 0.05) were observed for E. cloacae and P. agglomerans. Therefore, cell hydrophobicity, incubation time, and temperature affected the ability of the dominant bacteria to form biofilms.
