Contribution to the study of biofilms in the dairy industry: characterization and control strategies

The presence of biofilms in the dairy industry is a major problem in terms of quality, technology and potentially public health. Biofilms can form on different surface types and particularly on stainless steel, which is used for the majority of dairy processing equipment. Dairy biofilms include a complex microbial ecosystem that includes pathogen or spoiling microorganisms. These undesirable microorganisms are responsible for product rejection, economic losses or even foodborne illnesses. In addition to these problems, biofilms are responsible for mechanical blockages and the impedance of the heat transfer process and increase the corrosion rate of the surfaces. For these reasons, the contact surfaces must be cleaned and disinfected adequately to avoid or control the formation of biofilm. Despite data from the literature on the nature and formation of biofilms in the dairy sector, the results are incomplete and disregard many parameters such as milk composition, organic or inorganic content, and environmental or operational conditions. Different laboratory works on the formation of biofilms using pure culture bacteria found in the dairy sector have been realized. However, studies on the formation and dynamics of biofilms from complex indigenous flora of milk have, to our knowledge, never been investigated on stainless steel surfaces. Recent developments in metagenomics, including high-throughput sequencing, generate new information on microbial populations. These data will make it possible to understand the priority of research aimed at promoting the development and establishment of new strategies for the elimination of present biofilms and/or slowing down their formation on industrial surfaces.

The general objective of this project is to develop new knowledge on the formation, structure and composition of dairy biofilms and to use this new data for the development of an effective approach for better control of phenomenon in the dairy industry. An approach using biofilm model systems in a bioreactor combined with metagenomics. The following specific objectives will be pursued: 1) Characterize the physicochemical and microbiological plans of the biofilms encountered in dairy processing plants; 2) Simulate the formation of biofilms and study the technological and compositional parameters; 3) Develop new formulas and assess their potential to fight biofilms in the dairyindustry.