Enzyme-based strategy to eradicate monospecies Macrococcus caseolyticus biofilm contamination in dairy industries

Abstract The formation of undesirable microbial biofilms in dairy industries is the main cause of chemical cleaning agent ineffectiveness. Biofilm-associated contamination represents one of the major threats to dairy industry. In this study, 197 bacterial strains were isolated from the milk collection centre and neighbouring farms. Six strains were selected according to their ability to form a thick biofilm on polystyrene microplates and on stainless steel surfaces. The biofilm formed by Macrococcus caseolyticus was used as a model for the evaluation of eradication efficacy. Protease, lipase, cellulase, α-amylase and DNase enzymes were applied to treat biofilms. Moreover, buffer composition was improved to increase the diffusion of molecules inside the formed biofilm and to kill bacteria by surfactin addition. Results revealed that Macrococcus monospecies biofilm removal exceeded 50%. Moreover, when an enzymatic cocktail was applied, the biofilm removal was more efficient compared with the use of the chemical detergent BASO CTC.