Microbial biofilms in the food processing industry--should they be a concern?

Biofilm formation will occur on solid surfaces in contact with a liquid. Organic and inorganic material in the liquid sediment onto the solid material. Subsequently, biologically active microorganisms will be attracted to this conditioned surface and adhere to it. The microbial cells will initiate growth, form an attachment matrix and develop into a complex community forming a microbial biofilm. Such microbial biofilms are common on solid surfaces in contact with many different kinds of liquids, fresh water, sea water, oil, milk and so on. These biofilms may be of benefit or be detrimental to the environment where they form. The goal of this review has been to summarize the literature on the development of microbial biofilms in these different environments with particular emphasis on what occurs in the environment of a food processing plant. Methods to control adherent microorganisms and subsequent biofilms in the food processing plant are discussed. It is apparent from the data that has been reviewed that the potential for the development of microbial biofilms in the environment of the food processing plant exists. However, the cleaning and sanitizing practices carried out in the food industry have been shown to control biofilm formation on food contact surfaces. Microbial attachment has been shown to occur on non-food contact surfaces and these attached microbes, if left undisturbed, will form biofilms. The potential for contamination of food with undesirable spoilage and pathogenic bacteria from attached microbes and biofilms exists in these food processing systems. Biofilm formation on non-food contact surfaces needs to be studied further and methods developed to prevent and control these biofilms.