Biofilms of thermophilic bacilli isolated from dairy processing plants and efficacy of sanitizers.

In many environments, bacteria can attach to a surface and grow into multicellular structures, otherwise known as biofilms. Many systems for studying these biofilms in the laboratory are available. To study biofilms of the thermophilic bacilli in milk powder-manufacturing plants, standard laboratory biofilm techniques need to be adapted. The focus of this chapter is on techniques that can be used for growing and analyzing biofilms of thermophilic bacilli that are isolated from dairy processing plants. These techniques include laboratory methods as well as how to set up a pilot-scale experiment. The laboratory methods consist of a microtiter plate assay, which is used for strain selection, and the CDC reactor, which is used for testing sanitizers and antimicrobial surfaces. In dairy processing, if a new sanitizer or antimicrobial surface appears to be promising, it is useful to carry out pilot-scale experiments before introducing it to a manufacturing plant. We describe how to set up a pilot-scale experiment for testing the efficacy of sanitizers against the thermophilic bacilli.