Proteomic analysis of hexahydro-β-acids/hydroxypropyl-β-cyclodextrin inhibit Listeria monocytogenes.

Food safety affected by food-borne pathogen has received increasing attention by researchers. Listeria monocytogenes (L. monocytogenes), widespread in the environment, could easily cause some diseases. The aim of this study was to investigate how L. monocytogenes ATCC 19,115 regulated and shaped its proteome in response to hexahydro-β-acids (HBA) formed inclusion complex with hydroxypropyl-β-cyclodextrin (HP-β-CD), compared to untreated cells growing under optimal conditions. HP-β-CD enhanced the solubility of HBA to 0.589 g/100 mL. The minimum inhibitory concentration (MIC) and the minimal bactericidal concentration (MBC) of HBA/HP-β-CD to L. monocytogenes were 25 μg/mL and 100 μg/mL, respectively. Scanning electron microscope (SEM) images demonstrated that HBA could destroy the cell membrane of L. monocytogenes. The proteomic analysis revealed that 2882 proteins were initially identified, among which 153 and 201 proteins were differentially upregulated and downregulated respectively. Changes of L. monocytogenes proteome in response to treatments were mainly related to carbohydrate metabolism, protein synthesis, ribosome composition proteins, cell wall composition proteins, and cell division anomalies process. This research is conducive to understanding the molecular mechanisms underlying the inhibiting effects of HBA/HP-β-CD against L. monocytogenes, providing novel insights for further development of HBA/HP-β-CD antimicrobial agents. KEY POINTS: • MIC and MBC of HBA/HP-β-CD to L. monocytogenes were 25 μg/mL and 100 μg/mL. • HBA/HP-β-CD cause significant changes in bacterial proteome. • The process of ribosome composition and carbohydrate metabolism was inhibited.