1 - Biofilms in the food and beverage industries: an introduction

Abstract

Microbes, (bacteria, fungi, yeasts, moulds, viruses, etc.) are primarily found in two forms, either floating freely in water (planktonic), or attached to a surface (sessile) where they congregate in large numbers to form a film or slime layer known as a biofilm. Although planktonic microbes have been studied for many decades, it is only in the past two decades that industry has begun to understand and appreciate the complexity of a biofilm as a living organism and the huge problems biofilm formation causes in industry. It is now acknowledged that biofilms have huge cost implications to industry and can negatively affect a company's profitability. Biofilm is extremely difficult to remove and control. It is common knowledge that many chemical biocides are ineffective against biofilm and, at best, merely control planktonic microbes – leaving the biofilm intact to continue to recontaminate, corrode and to build resistance against antimicrobial compounds. The added danger then is when a particularly undesired pathogen (e.g., E. coli in food processing, Legionella in cooling towers, Pseudomonas in poultry rearing) enters a system and becomes attached to the biofilm, it becomes extremely difficult to remove and control, causing enormous problems that often result in production and plant shut-downs – costing companies millions in lost revenue.