Bacteria can adhere to foods or food contact surfaces and form biofilms, which may cause equipment damage, food spoilage, and even human diseases. As the major form of bacteria in the food industry, mixed-species biofilms often have a stronger resistance to disinfectants and antibiotics compared with single-species biofilm. However, the formation and inter-species interactions of mixed-species biofilms are quite complicated, and its potential effects in the food industry remain to be explored. In this review, we summarize the formation and inter-species interactions of mixed-species biofilms and novel control strategies developed in recent years, and discuss future trends in the prevention and control of mixedspecies biofilms in the food industry. This review aims to provide a theoretical basis for further research of mixed-species biofilms in the food industry and the development of efficient novel control strategies, in order to better safeguard food safety and public health.

The photodynamic inactivation of common pathogenic (Vibrio parahaemolyticus) and spoilage (Shewanella putrefaction) bacteria in aquatic products was investigated using curcumin as a photosensitizer. Viable cell counts, cell regrowth capacity, cell surface morphology, reactive oxygen species (ROS) level, biofilm biomass and cell viability were detected before and after photodynamic treatment, and the structural parameters of biofilms were further analyzed. The results showed that when the final concentration of curcumin was 3.0 or 10 μmol/L, and the illumination time was 8 min, the colony number of V. parahaemolyticus and S. putrefaciens were reduced by more than 7 (lg(CFU/mL)). The antibacterial mechanism was by producing a large amount of ROS, leading to the breakdown of the bacterial cell wall and eventually cell lysis and death. In addition, when the illumination time was 60 min, the eradication rates of V. parahaemolyticus and S. putrefaciens biofilms were about 70% and 62% for curcumin concentrations of 30 and 50 μmol/L, respectively. This study may provide new ideas for the design of a new photodynamic technology (PDT) for use in the food industry.