Microbes in the system
‘Microbe’ is an overly general term for a wide range of bacteria, fungi and yeasts that are frequently found in air and water, and are capable of building themselves a comfortable home in fuel supply storage tanks and distribution systems. These micron-sized cells (much smaller than the diameter of a human hair) readily multiply to form organised microbial communities in the presence of water, trace elements required for cell growth, and a suitable food source such as biodiesel or aviation fuel. Once growth has started, these communities can rapidly form microbial mats or ‘biofilms’ that can coat tank walls, plug fuel supply filters, and even lead to the corrosion of tanks and other metal parts. Fortunately, in-line filters at service station pumps are effective at removing microbes from the fuel during the dispensing process. However, frequently blocked fuel filters often provide an early warning that microbial growth may be flourishing in storage tanks.