Combined Effects of the Phage and Sodium Hypochlorite for Reducing Biofilm.

are significant spoilage bacteria in raw milk and dairy products, primarily due to their ability to form biofilms and resist disinfection. This study explored the effects of the phage combined with sodium hypochlorite in reducing biofilms on stainless steel at various temperatures and ages. Biofilms were formed using UFV 041 in UHT milk, incubated at 4 °C and 30 °C for 2 and 7 days. Two lytic phages were compared, with showing superior activity, reducing cell counts by 0.8 to 2.0 logs CFU/cm depending on conditions. Increasing the contact time of the phage from 4 to 8 h did not significantly affect the reduction in mature biofilms. The individual treatments of the phage and sodium hypochlorite (100 mg/L) reduced bacterial counts by 0.9 and 0.6 log CFU/cm at 30 °C, and 1.3 and 1.2 log CFU/cm at 4 °C, respectively. However, their sequential application achieved greater reductions, reaching 1.3 and 1.8 log CFU/cm for biofilms formed at 30 °C and 4 °C, respectively. These findings suggest a promising strategy for controlling in the food industry. Our findings suggest that the phage combined with chlorine improves the removal of biofilms.